Switch to keybase go-crypto (for some elliptic curve key) + test (#1925)

* Switch to keybase go-crypto (for some elliptic curve key) + test

* Use assert.NoError 

and add a little more context to failing test description

* Use assert.(No)Error everywhere 🌈

and assert.Error in place of .Nil/.NotNil
This commit is contained in:
Antoine GIRARD 2017-06-14 02:43:43 +02:00 committed by Lunny Xiao
parent 5e92b82ac6
commit 274149dd14
56 changed files with 10621 additions and 925 deletions

27
vendor/github.com/keybase/go-crypto/LICENSE generated vendored Normal file
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Copyright (c) 2009 The Go Authors. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google Inc. nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

22
vendor/github.com/keybase/go-crypto/PATENTS generated vendored Normal file
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Additional IP Rights Grant (Patents)
"This implementation" means the copyrightable works distributed by
Google as part of the Go project.
Google hereby grants to You a perpetual, worldwide, non-exclusive,
no-charge, royalty-free, irrevocable (except as stated in this section)
patent license to make, have made, use, offer to sell, sell, import,
transfer and otherwise run, modify and propagate the contents of this
implementation of Go, where such license applies only to those patent
claims, both currently owned or controlled by Google and acquired in
the future, licensable by Google that are necessarily infringed by this
implementation of Go. This grant does not include claims that would be
infringed only as a consequence of further modification of this
implementation. If you or your agent or exclusive licensee institute or
order or agree to the institution of patent litigation against any
entity (including a cross-claim or counterclaim in a lawsuit) alleging
that this implementation of Go or any code incorporated within this
implementation of Go constitutes direct or contributory patent
infringement, or inducement of patent infringement, then any patent
rights granted to you under this License for this implementation of Go
shall terminate as of the date such litigation is filed.

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// Package brainpool implements Brainpool elliptic curves.
// Implementation of rcurves is from github.com/ebfe/brainpool
// Note that these curves are implemented with naive, non-constant time operations
// and are likely not suitable for enviroments where timing attacks are a concern.
package brainpool
import (
"crypto/elliptic"
"math/big"
"sync"
)
var (
once sync.Once
p256t1, p384t1, p512t1 *elliptic.CurveParams
p256r1, p384r1, p512r1 *rcurve
)
func initAll() {
initP256t1()
initP384t1()
initP512t1()
initP256r1()
initP384r1()
initP512r1()
}
func initP256t1() {
p256t1 = &elliptic.CurveParams{Name: "brainpoolP256t1"}
p256t1.P, _ = new(big.Int).SetString("A9FB57DBA1EEA9BC3E660A909D838D726E3BF623D52620282013481D1F6E5377", 16)
p256t1.N, _ = new(big.Int).SetString("A9FB57DBA1EEA9BC3E660A909D838D718C397AA3B561A6F7901E0E82974856A7", 16)
p256t1.B, _ = new(big.Int).SetString("662C61C430D84EA4FE66A7733D0B76B7BF93EBC4AF2F49256AE58101FEE92B04", 16)
p256t1.Gx, _ = new(big.Int).SetString("A3E8EB3CC1CFE7B7732213B23A656149AFA142C47AAFBC2B79A191562E1305F4", 16)
p256t1.Gy, _ = new(big.Int).SetString("2D996C823439C56D7F7B22E14644417E69BCB6DE39D027001DABE8F35B25C9BE", 16)
p256t1.BitSize = 256
}
func initP256r1() {
twisted := p256t1
params := &elliptic.CurveParams{
Name: "brainpoolP256r1",
P: twisted.P,
N: twisted.N,
BitSize: twisted.BitSize,
}
params.Gx, _ = new(big.Int).SetString("8BD2AEB9CB7E57CB2C4B482FFC81B7AFB9DE27E1E3BD23C23A4453BD9ACE3262", 16)
params.Gy, _ = new(big.Int).SetString("547EF835C3DAC4FD97F8461A14611DC9C27745132DED8E545C1D54C72F046997", 16)
z, _ := new(big.Int).SetString("3E2D4BD9597B58639AE7AA669CAB9837CF5CF20A2C852D10F655668DFC150EF0", 16)
p256r1 = newrcurve(twisted, params, z)
}
func initP384t1() {
p384t1 = &elliptic.CurveParams{Name: "brainpoolP384t1"}
p384t1.P, _ = new(big.Int).SetString("8CB91E82A3386D280F5D6F7E50E641DF152F7109ED5456B412B1DA197FB71123ACD3A729901D1A71874700133107EC53", 16)
p384t1.N, _ = new(big.Int).SetString("8CB91E82A3386D280F5D6F7E50E641DF152F7109ED5456B31F166E6CAC0425A7CF3AB6AF6B7FC3103B883202E9046565", 16)
p384t1.B, _ = new(big.Int).SetString("7F519EADA7BDA81BD826DBA647910F8C4B9346ED8CCDC64E4B1ABD11756DCE1D2074AA263B88805CED70355A33B471EE", 16)
p384t1.Gx, _ = new(big.Int).SetString("18DE98B02DB9A306F2AFCD7235F72A819B80AB12EBD653172476FECD462AABFFC4FF191B946A5F54D8D0AA2F418808CC", 16)
p384t1.Gy, _ = new(big.Int).SetString("25AB056962D30651A114AFD2755AD336747F93475B7A1FCA3B88F2B6A208CCFE469408584DC2B2912675BF5B9E582928", 16)
p384t1.BitSize = 384
}
func initP384r1() {
twisted := p384t1
params := &elliptic.CurveParams{
Name: "brainpoolP384r1",
P: twisted.P,
N: twisted.N,
BitSize: twisted.BitSize,
}
params.Gx, _ = new(big.Int).SetString("1D1C64F068CF45FFA2A63A81B7C13F6B8847A3E77EF14FE3DB7FCAFE0CBD10E8E826E03436D646AAEF87B2E247D4AF1E", 16)
params.Gy, _ = new(big.Int).SetString("8ABE1D7520F9C2A45CB1EB8E95CFD55262B70B29FEEC5864E19C054FF99129280E4646217791811142820341263C5315", 16)
z, _ := new(big.Int).SetString("41DFE8DD399331F7166A66076734A89CD0D2BCDB7D068E44E1F378F41ECBAE97D2D63DBC87BCCDDCCC5DA39E8589291C", 16)
p384r1 = newrcurve(twisted, params, z)
}
func initP512t1() {
p512t1 = &elliptic.CurveParams{Name: "brainpoolP512t1"}
p512t1.P, _ = new(big.Int).SetString("AADD9DB8DBE9C48B3FD4E6AE33C9FC07CB308DB3B3C9D20ED6639CCA703308717D4D9B009BC66842AECDA12AE6A380E62881FF2F2D82C68528AA6056583A48F3", 16)
p512t1.N, _ = new(big.Int).SetString("AADD9DB8DBE9C48B3FD4E6AE33C9FC07CB308DB3B3C9D20ED6639CCA70330870553E5C414CA92619418661197FAC10471DB1D381085DDADDB58796829CA90069", 16)
p512t1.B, _ = new(big.Int).SetString("7CBBBCF9441CFAB76E1890E46884EAE321F70C0BCB4981527897504BEC3E36A62BCDFA2304976540F6450085F2DAE145C22553B465763689180EA2571867423E", 16)
p512t1.Gx, _ = new(big.Int).SetString("640ECE5C12788717B9C1BA06CBC2A6FEBA85842458C56DDE9DB1758D39C0313D82BA51735CDB3EA499AA77A7D6943A64F7A3F25FE26F06B51BAA2696FA9035DA", 16)
p512t1.Gy, _ = new(big.Int).SetString("5B534BD595F5AF0FA2C892376C84ACE1BB4E3019B71634C01131159CAE03CEE9D9932184BEEF216BD71DF2DADF86A627306ECFF96DBB8BACE198B61E00F8B332", 16)
p512t1.BitSize = 512
}
func initP512r1() {
twisted := p512t1
params := &elliptic.CurveParams{
Name: "brainpoolP512r1",
P: twisted.P,
N: twisted.N,
BitSize: twisted.BitSize,
}
params.Gx, _ = new(big.Int).SetString("81AEE4BDD82ED9645A21322E9C4C6A9385ED9F70B5D916C1B43B62EEF4D0098EFF3B1F78E2D0D48D50D1687B93B97D5F7C6D5047406A5E688B352209BCB9F822", 16)
params.Gy, _ = new(big.Int).SetString("7DDE385D566332ECC0EABFA9CF7822FDF209F70024A57B1AA000C55B881F8111B2DCDE494A5F485E5BCA4BD88A2763AED1CA2B2FA8F0540678CD1E0F3AD80892", 16)
z, _ := new(big.Int).SetString("12EE58E6764838B69782136F0F2D3BA06E27695716054092E60A80BEDB212B64E585D90BCE13761F85C3F1D2A64E3BE8FEA2220F01EBA5EEB0F35DBD29D922AB", 16)
p512r1 = newrcurve(twisted, params, z)
}
// P256t1 returns a Curve which implements Brainpool P256t1 (see RFC 5639, section 3.4)
func P256t1() elliptic.Curve {
once.Do(initAll)
return p256t1
}
// P256r1 returns a Curve which implements Brainpool P256r1 (see RFC 5639, section 3.4)
func P256r1() elliptic.Curve {
once.Do(initAll)
return p256r1
}
// P384t1 returns a Curve which implements Brainpool P384t1 (see RFC 5639, section 3.6)
func P384t1() elliptic.Curve {
once.Do(initAll)
return p384t1
}
// P384r1 returns a Curve which implements Brainpool P384r1 (see RFC 5639, section 3.6)
func P384r1() elliptic.Curve {
once.Do(initAll)
return p384r1
}
// P512t1 returns a Curve which implements Brainpool P512t1 (see RFC 5639, section 3.7)
func P512t1() elliptic.Curve {
once.Do(initAll)
return p512t1
}
// P512r1 returns a Curve which implements Brainpool P512r1 (see RFC 5639, section 3.7)
func P512r1() elliptic.Curve {
once.Do(initAll)
return p512r1
}

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package brainpool
import (
"crypto/elliptic"
"math/big"
)
var _ elliptic.Curve = (*rcurve)(nil)
type rcurve struct {
twisted elliptic.Curve
params *elliptic.CurveParams
z *big.Int
zinv *big.Int
z2 *big.Int
z3 *big.Int
zinv2 *big.Int
zinv3 *big.Int
}
var (
two = big.NewInt(2)
three = big.NewInt(3)
)
func newrcurve(twisted elliptic.Curve, params *elliptic.CurveParams, z *big.Int) *rcurve {
zinv := new(big.Int).ModInverse(z, params.P)
return &rcurve{
twisted: twisted,
params: params,
z: z,
zinv: zinv,
z2: new(big.Int).Exp(z, two, params.P),
z3: new(big.Int).Exp(z, three, params.P),
zinv2: new(big.Int).Exp(zinv, two, params.P),
zinv3: new(big.Int).Exp(zinv, three, params.P),
}
}
func (curve *rcurve) toTwisted(x, y *big.Int) (*big.Int, *big.Int) {
var tx, ty big.Int
tx.Mul(x, curve.z2)
tx.Mod(&tx, curve.params.P)
ty.Mul(y, curve.z3)
ty.Mod(&ty, curve.params.P)
return &tx, &ty
}
func (curve *rcurve) fromTwisted(tx, ty *big.Int) (*big.Int, *big.Int) {
var x, y big.Int
x.Mul(tx, curve.zinv2)
x.Mod(&x, curve.params.P)
y.Mul(ty, curve.zinv3)
y.Mod(&y, curve.params.P)
return &x, &y
}
func (curve *rcurve) Params() *elliptic.CurveParams {
return curve.params
}
func (curve *rcurve) IsOnCurve(x, y *big.Int) bool {
return curve.twisted.IsOnCurve(curve.toTwisted(x, y))
}
func (curve *rcurve) Add(x1, y1, x2, y2 *big.Int) (x, y *big.Int) {
tx1, ty1 := curve.toTwisted(x1, y1)
tx2, ty2 := curve.toTwisted(x2, y2)
return curve.fromTwisted(curve.twisted.Add(tx1, ty1, tx2, ty2))
}
func (curve *rcurve) Double(x1, y1 *big.Int) (x, y *big.Int) {
return curve.fromTwisted(curve.twisted.Double(curve.toTwisted(x1, y1)))
}
func (curve *rcurve) ScalarMult(x1, y1 *big.Int, scalar []byte) (x, y *big.Int) {
tx1, ty1 := curve.toTwisted(x1, y1)
return curve.fromTwisted(curve.twisted.ScalarMult(tx1, ty1, scalar))
}
func (curve *rcurve) ScalarBaseMult(scalar []byte) (x, y *big.Int) {
return curve.fromTwisted(curve.twisted.ScalarBaseMult(scalar))
}

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vendor/github.com/keybase/go-crypto/cast5/cast5.go generated vendored Normal file
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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package cast5 implements CAST5, as defined in RFC 2144. CAST5 is a common
// OpenPGP cipher.
package cast5
import "errors"
const BlockSize = 8
const KeySize = 16
type Cipher struct {
masking [16]uint32
rotate [16]uint8
}
func NewCipher(key []byte) (c *Cipher, err error) {
if len(key) != KeySize {
return nil, errors.New("CAST5: keys must be 16 bytes")
}
c = new(Cipher)
c.keySchedule(key)
return
}
func (c *Cipher) BlockSize() int {
return BlockSize
}
func (c *Cipher) Encrypt(dst, src []byte) {
l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
l, r = r, l^f1(r, c.masking[0], c.rotate[0])
l, r = r, l^f2(r, c.masking[1], c.rotate[1])
l, r = r, l^f3(r, c.masking[2], c.rotate[2])
l, r = r, l^f1(r, c.masking[3], c.rotate[3])
l, r = r, l^f2(r, c.masking[4], c.rotate[4])
l, r = r, l^f3(r, c.masking[5], c.rotate[5])
l, r = r, l^f1(r, c.masking[6], c.rotate[6])
l, r = r, l^f2(r, c.masking[7], c.rotate[7])
l, r = r, l^f3(r, c.masking[8], c.rotate[8])
l, r = r, l^f1(r, c.masking[9], c.rotate[9])
l, r = r, l^f2(r, c.masking[10], c.rotate[10])
l, r = r, l^f3(r, c.masking[11], c.rotate[11])
l, r = r, l^f1(r, c.masking[12], c.rotate[12])
l, r = r, l^f2(r, c.masking[13], c.rotate[13])
l, r = r, l^f3(r, c.masking[14], c.rotate[14])
l, r = r, l^f1(r, c.masking[15], c.rotate[15])
dst[0] = uint8(r >> 24)
dst[1] = uint8(r >> 16)
dst[2] = uint8(r >> 8)
dst[3] = uint8(r)
dst[4] = uint8(l >> 24)
dst[5] = uint8(l >> 16)
dst[6] = uint8(l >> 8)
dst[7] = uint8(l)
}
func (c *Cipher) Decrypt(dst, src []byte) {
l := uint32(src[0])<<24 | uint32(src[1])<<16 | uint32(src[2])<<8 | uint32(src[3])
r := uint32(src[4])<<24 | uint32(src[5])<<16 | uint32(src[6])<<8 | uint32(src[7])
l, r = r, l^f1(r, c.masking[15], c.rotate[15])
l, r = r, l^f3(r, c.masking[14], c.rotate[14])
l, r = r, l^f2(r, c.masking[13], c.rotate[13])
l, r = r, l^f1(r, c.masking[12], c.rotate[12])
l, r = r, l^f3(r, c.masking[11], c.rotate[11])
l, r = r, l^f2(r, c.masking[10], c.rotate[10])
l, r = r, l^f1(r, c.masking[9], c.rotate[9])
l, r = r, l^f3(r, c.masking[8], c.rotate[8])
l, r = r, l^f2(r, c.masking[7], c.rotate[7])
l, r = r, l^f1(r, c.masking[6], c.rotate[6])
l, r = r, l^f3(r, c.masking[5], c.rotate[5])
l, r = r, l^f2(r, c.masking[4], c.rotate[4])
l, r = r, l^f1(r, c.masking[3], c.rotate[3])
l, r = r, l^f3(r, c.masking[2], c.rotate[2])
l, r = r, l^f2(r, c.masking[1], c.rotate[1])
l, r = r, l^f1(r, c.masking[0], c.rotate[0])
dst[0] = uint8(r >> 24)
dst[1] = uint8(r >> 16)
dst[2] = uint8(r >> 8)
dst[3] = uint8(r)
dst[4] = uint8(l >> 24)
dst[5] = uint8(l >> 16)
dst[6] = uint8(l >> 8)
dst[7] = uint8(l)
}
type keyScheduleA [4][7]uint8
type keyScheduleB [4][5]uint8
// keyScheduleRound contains the magic values for a round of the key schedule.
// The keyScheduleA deals with the lines like:
// z0z1z2z3 = x0x1x2x3 ^ S5[xD] ^ S6[xF] ^ S7[xC] ^ S8[xE] ^ S7[x8]
// Conceptually, both x and z are in the same array, x first. The first
// element describes which word of this array gets written to and the
// second, which word gets read. So, for the line above, it's "4, 0", because
// it's writing to the first word of z, which, being after x, is word 4, and
// reading from the first word of x: word 0.
//
// Next are the indexes into the S-boxes. Now the array is treated as bytes. So
// "xD" is 0xd. The first byte of z is written as "16 + 0", just to be clear
// that it's z that we're indexing.
//
// keyScheduleB deals with lines like:
// K1 = S5[z8] ^ S6[z9] ^ S7[z7] ^ S8[z6] ^ S5[z2]
// "K1" is ignored because key words are always written in order. So the five
// elements are the S-box indexes. They use the same form as in keyScheduleA,
// above.
type keyScheduleRound struct{}
type keySchedule []keyScheduleRound
var schedule = []struct {
a keyScheduleA
b keyScheduleB
}{
{
keyScheduleA{
{4, 0, 0xd, 0xf, 0xc, 0xe, 0x8},
{5, 2, 16 + 0, 16 + 2, 16 + 1, 16 + 3, 0xa},
{6, 3, 16 + 7, 16 + 6, 16 + 5, 16 + 4, 9},
{7, 1, 16 + 0xa, 16 + 9, 16 + 0xb, 16 + 8, 0xb},
},
keyScheduleB{
{16 + 8, 16 + 9, 16 + 7, 16 + 6, 16 + 2},
{16 + 0xa, 16 + 0xb, 16 + 5, 16 + 4, 16 + 6},
{16 + 0xc, 16 + 0xd, 16 + 3, 16 + 2, 16 + 9},
{16 + 0xe, 16 + 0xf, 16 + 1, 16 + 0, 16 + 0xc},
},
},
{
keyScheduleA{
{0, 6, 16 + 5, 16 + 7, 16 + 4, 16 + 6, 16 + 0},
{1, 4, 0, 2, 1, 3, 16 + 2},
{2, 5, 7, 6, 5, 4, 16 + 1},
{3, 7, 0xa, 9, 0xb, 8, 16 + 3},
},
keyScheduleB{
{3, 2, 0xc, 0xd, 8},
{1, 0, 0xe, 0xf, 0xd},
{7, 6, 8, 9, 3},
{5, 4, 0xa, 0xb, 7},
},
},
{
keyScheduleA{
{4, 0, 0xd, 0xf, 0xc, 0xe, 8},
{5, 2, 16 + 0, 16 + 2, 16 + 1, 16 + 3, 0xa},
{6, 3, 16 + 7, 16 + 6, 16 + 5, 16 + 4, 9},
{7, 1, 16 + 0xa, 16 + 9, 16 + 0xb, 16 + 8, 0xb},
},
keyScheduleB{
{16 + 3, 16 + 2, 16 + 0xc, 16 + 0xd, 16 + 9},
{16 + 1, 16 + 0, 16 + 0xe, 16 + 0xf, 16 + 0xc},
{16 + 7, 16 + 6, 16 + 8, 16 + 9, 16 + 2},
{16 + 5, 16 + 4, 16 + 0xa, 16 + 0xb, 16 + 6},
},
},
{
keyScheduleA{
{0, 6, 16 + 5, 16 + 7, 16 + 4, 16 + 6, 16 + 0},
{1, 4, 0, 2, 1, 3, 16 + 2},
{2, 5, 7, 6, 5, 4, 16 + 1},
{3, 7, 0xa, 9, 0xb, 8, 16 + 3},
},
keyScheduleB{
{8, 9, 7, 6, 3},
{0xa, 0xb, 5, 4, 7},
{0xc, 0xd, 3, 2, 8},
{0xe, 0xf, 1, 0, 0xd},
},
},
}
func (c *Cipher) keySchedule(in []byte) {
var t [8]uint32
var k [32]uint32
for i := 0; i < 4; i++ {
j := i * 4
t[i] = uint32(in[j])<<24 | uint32(in[j+1])<<16 | uint32(in[j+2])<<8 | uint32(in[j+3])
}
x := []byte{6, 7, 4, 5}
ki := 0
for half := 0; half < 2; half++ {
for _, round := range schedule {
for j := 0; j < 4; j++ {
var a [7]uint8
copy(a[:], round.a[j][:])
w := t[a[1]]
w ^= sBox[4][(t[a[2]>>2]>>(24-8*(a[2]&3)))&0xff]
w ^= sBox[5][(t[a[3]>>2]>>(24-8*(a[3]&3)))&0xff]
w ^= sBox[6][(t[a[4]>>2]>>(24-8*(a[4]&3)))&0xff]
w ^= sBox[7][(t[a[5]>>2]>>(24-8*(a[5]&3)))&0xff]
w ^= sBox[x[j]][(t[a[6]>>2]>>(24-8*(a[6]&3)))&0xff]
t[a[0]] = w
}
for j := 0; j < 4; j++ {
var b [5]uint8
copy(b[:], round.b[j][:])
w := sBox[4][(t[b[0]>>2]>>(24-8*(b[0]&3)))&0xff]
w ^= sBox[5][(t[b[1]>>2]>>(24-8*(b[1]&3)))&0xff]
w ^= sBox[6][(t[b[2]>>2]>>(24-8*(b[2]&3)))&0xff]
w ^= sBox[7][(t[b[3]>>2]>>(24-8*(b[3]&3)))&0xff]
w ^= sBox[4+j][(t[b[4]>>2]>>(24-8*(b[4]&3)))&0xff]
k[ki] = w
ki++
}
}
}
for i := 0; i < 16; i++ {
c.masking[i] = k[i]
c.rotate[i] = uint8(k[16+i] & 0x1f)
}
}
// These are the three 'f' functions. See RFC 2144, section 2.2.
func f1(d, m uint32, r uint8) uint32 {
t := m + d
I := (t << r) | (t >> (32 - r))
return ((sBox[0][I>>24] ^ sBox[1][(I>>16)&0xff]) - sBox[2][(I>>8)&0xff]) + sBox[3][I&0xff]
}
func f2(d, m uint32, r uint8) uint32 {
t := m ^ d
I := (t << r) | (t >> (32 - r))
return ((sBox[0][I>>24] - sBox[1][(I>>16)&0xff]) + sBox[2][(I>>8)&0xff]) ^ sBox[3][I&0xff]
}
func f3(d, m uint32, r uint8) uint32 {
t := m - d
I := (t << r) | (t >> (32 - r))
return ((sBox[0][I>>24] + sBox[1][(I>>16)&0xff]) ^ sBox[2][(I>>8)&0xff]) - sBox[3][I&0xff]
}
var sBox = [8][256]uint32{
{
0x30fb40d4, 0x9fa0ff0b, 0x6beccd2f, 0x3f258c7a, 0x1e213f2f, 0x9c004dd3, 0x6003e540, 0xcf9fc949,
0xbfd4af27, 0x88bbbdb5, 0xe2034090, 0x98d09675, 0x6e63a0e0, 0x15c361d2, 0xc2e7661d, 0x22d4ff8e,
0x28683b6f, 0xc07fd059, 0xff2379c8, 0x775f50e2, 0x43c340d3, 0xdf2f8656, 0x887ca41a, 0xa2d2bd2d,
0xa1c9e0d6, 0x346c4819, 0x61b76d87, 0x22540f2f, 0x2abe32e1, 0xaa54166b, 0x22568e3a, 0xa2d341d0,
0x66db40c8, 0xa784392f, 0x004dff2f, 0x2db9d2de, 0x97943fac, 0x4a97c1d8, 0x527644b7, 0xb5f437a7,
0xb82cbaef, 0xd751d159, 0x6ff7f0ed, 0x5a097a1f, 0x827b68d0, 0x90ecf52e, 0x22b0c054, 0xbc8e5935,
0x4b6d2f7f, 0x50bb64a2, 0xd2664910, 0xbee5812d, 0xb7332290, 0xe93b159f, 0xb48ee411, 0x4bff345d,
0xfd45c240, 0xad31973f, 0xc4f6d02e, 0x55fc8165, 0xd5b1caad, 0xa1ac2dae, 0xa2d4b76d, 0xc19b0c50,
0x882240f2, 0x0c6e4f38, 0xa4e4bfd7, 0x4f5ba272, 0x564c1d2f, 0xc59c5319, 0xb949e354, 0xb04669fe,
0xb1b6ab8a, 0xc71358dd, 0x6385c545, 0x110f935d, 0x57538ad5, 0x6a390493, 0xe63d37e0, 0x2a54f6b3,
0x3a787d5f, 0x6276a0b5, 0x19a6fcdf, 0x7a42206a, 0x29f9d4d5, 0xf61b1891, 0xbb72275e, 0xaa508167,
0x38901091, 0xc6b505eb, 0x84c7cb8c, 0x2ad75a0f, 0x874a1427, 0xa2d1936b, 0x2ad286af, 0xaa56d291,
0xd7894360, 0x425c750d, 0x93b39e26, 0x187184c9, 0x6c00b32d, 0x73e2bb14, 0xa0bebc3c, 0x54623779,
0x64459eab, 0x3f328b82, 0x7718cf82, 0x59a2cea6, 0x04ee002e, 0x89fe78e6, 0x3fab0950, 0x325ff6c2,
0x81383f05, 0x6963c5c8, 0x76cb5ad6, 0xd49974c9, 0xca180dcf, 0x380782d5, 0xc7fa5cf6, 0x8ac31511,
0x35e79e13, 0x47da91d0, 0xf40f9086, 0xa7e2419e, 0x31366241, 0x051ef495, 0xaa573b04, 0x4a805d8d,
0x548300d0, 0x00322a3c, 0xbf64cddf, 0xba57a68e, 0x75c6372b, 0x50afd341, 0xa7c13275, 0x915a0bf5,
0x6b54bfab, 0x2b0b1426, 0xab4cc9d7, 0x449ccd82, 0xf7fbf265, 0xab85c5f3, 0x1b55db94, 0xaad4e324,
0xcfa4bd3f, 0x2deaa3e2, 0x9e204d02, 0xc8bd25ac, 0xeadf55b3, 0xd5bd9e98, 0xe31231b2, 0x2ad5ad6c,
0x954329de, 0xadbe4528, 0xd8710f69, 0xaa51c90f, 0xaa786bf6, 0x22513f1e, 0xaa51a79b, 0x2ad344cc,
0x7b5a41f0, 0xd37cfbad, 0x1b069505, 0x41ece491, 0xb4c332e6, 0x032268d4, 0xc9600acc, 0xce387e6d,
0xbf6bb16c, 0x6a70fb78, 0x0d03d9c9, 0xd4df39de, 0xe01063da, 0x4736f464, 0x5ad328d8, 0xb347cc96,
0x75bb0fc3, 0x98511bfb, 0x4ffbcc35, 0xb58bcf6a, 0xe11f0abc, 0xbfc5fe4a, 0xa70aec10, 0xac39570a,
0x3f04442f, 0x6188b153, 0xe0397a2e, 0x5727cb79, 0x9ceb418f, 0x1cacd68d, 0x2ad37c96, 0x0175cb9d,
0xc69dff09, 0xc75b65f0, 0xd9db40d8, 0xec0e7779, 0x4744ead4, 0xb11c3274, 0xdd24cb9e, 0x7e1c54bd,
0xf01144f9, 0xd2240eb1, 0x9675b3fd, 0xa3ac3755, 0xd47c27af, 0x51c85f4d, 0x56907596, 0xa5bb15e6,
0x580304f0, 0xca042cf1, 0x011a37ea, 0x8dbfaadb, 0x35ba3e4a, 0x3526ffa0, 0xc37b4d09, 0xbc306ed9,
0x98a52666, 0x5648f725, 0xff5e569d, 0x0ced63d0, 0x7c63b2cf, 0x700b45e1, 0xd5ea50f1, 0x85a92872,
0xaf1fbda7, 0xd4234870, 0xa7870bf3, 0x2d3b4d79, 0x42e04198, 0x0cd0ede7, 0x26470db8, 0xf881814c,
0x474d6ad7, 0x7c0c5e5c, 0xd1231959, 0x381b7298, 0xf5d2f4db, 0xab838653, 0x6e2f1e23, 0x83719c9e,
0xbd91e046, 0x9a56456e, 0xdc39200c, 0x20c8c571, 0x962bda1c, 0xe1e696ff, 0xb141ab08, 0x7cca89b9,
0x1a69e783, 0x02cc4843, 0xa2f7c579, 0x429ef47d, 0x427b169c, 0x5ac9f049, 0xdd8f0f00, 0x5c8165bf,
},
{
0x1f201094, 0xef0ba75b, 0x69e3cf7e, 0x393f4380, 0xfe61cf7a, 0xeec5207a, 0x55889c94, 0x72fc0651,
0xada7ef79, 0x4e1d7235, 0xd55a63ce, 0xde0436ba, 0x99c430ef, 0x5f0c0794, 0x18dcdb7d, 0xa1d6eff3,
0xa0b52f7b, 0x59e83605, 0xee15b094, 0xe9ffd909, 0xdc440086, 0xef944459, 0xba83ccb3, 0xe0c3cdfb,
0xd1da4181, 0x3b092ab1, 0xf997f1c1, 0xa5e6cf7b, 0x01420ddb, 0xe4e7ef5b, 0x25a1ff41, 0xe180f806,
0x1fc41080, 0x179bee7a, 0xd37ac6a9, 0xfe5830a4, 0x98de8b7f, 0x77e83f4e, 0x79929269, 0x24fa9f7b,
0xe113c85b, 0xacc40083, 0xd7503525, 0xf7ea615f, 0x62143154, 0x0d554b63, 0x5d681121, 0xc866c359,
0x3d63cf73, 0xcee234c0, 0xd4d87e87, 0x5c672b21, 0x071f6181, 0x39f7627f, 0x361e3084, 0xe4eb573b,
0x602f64a4, 0xd63acd9c, 0x1bbc4635, 0x9e81032d, 0x2701f50c, 0x99847ab4, 0xa0e3df79, 0xba6cf38c,
0x10843094, 0x2537a95e, 0xf46f6ffe, 0xa1ff3b1f, 0x208cfb6a, 0x8f458c74, 0xd9e0a227, 0x4ec73a34,
0xfc884f69, 0x3e4de8df, 0xef0e0088, 0x3559648d, 0x8a45388c, 0x1d804366, 0x721d9bfd, 0xa58684bb,
0xe8256333, 0x844e8212, 0x128d8098, 0xfed33fb4, 0xce280ae1, 0x27e19ba5, 0xd5a6c252, 0xe49754bd,
0xc5d655dd, 0xeb667064, 0x77840b4d, 0xa1b6a801, 0x84db26a9, 0xe0b56714, 0x21f043b7, 0xe5d05860,
0x54f03084, 0x066ff472, 0xa31aa153, 0xdadc4755, 0xb5625dbf, 0x68561be6, 0x83ca6b94, 0x2d6ed23b,
0xeccf01db, 0xa6d3d0ba, 0xb6803d5c, 0xaf77a709, 0x33b4a34c, 0x397bc8d6, 0x5ee22b95, 0x5f0e5304,
0x81ed6f61, 0x20e74364, 0xb45e1378, 0xde18639b, 0x881ca122, 0xb96726d1, 0x8049a7e8, 0x22b7da7b,
0x5e552d25, 0x5272d237, 0x79d2951c, 0xc60d894c, 0x488cb402, 0x1ba4fe5b, 0xa4b09f6b, 0x1ca815cf,
0xa20c3005, 0x8871df63, 0xb9de2fcb, 0x0cc6c9e9, 0x0beeff53, 0xe3214517, 0xb4542835, 0x9f63293c,
0xee41e729, 0x6e1d2d7c, 0x50045286, 0x1e6685f3, 0xf33401c6, 0x30a22c95, 0x31a70850, 0x60930f13,
0x73f98417, 0xa1269859, 0xec645c44, 0x52c877a9, 0xcdff33a6, 0xa02b1741, 0x7cbad9a2, 0x2180036f,
0x50d99c08, 0xcb3f4861, 0xc26bd765, 0x64a3f6ab, 0x80342676, 0x25a75e7b, 0xe4e6d1fc, 0x20c710e6,
0xcdf0b680, 0x17844d3b, 0x31eef84d, 0x7e0824e4, 0x2ccb49eb, 0x846a3bae, 0x8ff77888, 0xee5d60f6,
0x7af75673, 0x2fdd5cdb, 0xa11631c1, 0x30f66f43, 0xb3faec54, 0x157fd7fa, 0xef8579cc, 0xd152de58,
0xdb2ffd5e, 0x8f32ce19, 0x306af97a, 0x02f03ef8, 0x99319ad5, 0xc242fa0f, 0xa7e3ebb0, 0xc68e4906,
0xb8da230c, 0x80823028, 0xdcdef3c8, 0xd35fb171, 0x088a1bc8, 0xbec0c560, 0x61a3c9e8, 0xbca8f54d,
0xc72feffa, 0x22822e99, 0x82c570b4, 0xd8d94e89, 0x8b1c34bc, 0x301e16e6, 0x273be979, 0xb0ffeaa6,
0x61d9b8c6, 0x00b24869, 0xb7ffce3f, 0x08dc283b, 0x43daf65a, 0xf7e19798, 0x7619b72f, 0x8f1c9ba4,
0xdc8637a0, 0x16a7d3b1, 0x9fc393b7, 0xa7136eeb, 0xc6bcc63e, 0x1a513742, 0xef6828bc, 0x520365d6,
0x2d6a77ab, 0x3527ed4b, 0x821fd216, 0x095c6e2e, 0xdb92f2fb, 0x5eea29cb, 0x145892f5, 0x91584f7f,
0x5483697b, 0x2667a8cc, 0x85196048, 0x8c4bacea, 0x833860d4, 0x0d23e0f9, 0x6c387e8a, 0x0ae6d249,
0xb284600c, 0xd835731d, 0xdcb1c647, 0xac4c56ea, 0x3ebd81b3, 0x230eabb0, 0x6438bc87, 0xf0b5b1fa,
0x8f5ea2b3, 0xfc184642, 0x0a036b7a, 0x4fb089bd, 0x649da589, 0xa345415e, 0x5c038323, 0x3e5d3bb9,
0x43d79572, 0x7e6dd07c, 0x06dfdf1e, 0x6c6cc4ef, 0x7160a539, 0x73bfbe70, 0x83877605, 0x4523ecf1,
},
{
0x8defc240, 0x25fa5d9f, 0xeb903dbf, 0xe810c907, 0x47607fff, 0x369fe44b, 0x8c1fc644, 0xaececa90,
0xbeb1f9bf, 0xeefbcaea, 0xe8cf1950, 0x51df07ae, 0x920e8806, 0xf0ad0548, 0xe13c8d83, 0x927010d5,
0x11107d9f, 0x07647db9, 0xb2e3e4d4, 0x3d4f285e, 0xb9afa820, 0xfade82e0, 0xa067268b, 0x8272792e,
0x553fb2c0, 0x489ae22b, 0xd4ef9794, 0x125e3fbc, 0x21fffcee, 0x825b1bfd, 0x9255c5ed, 0x1257a240,
0x4e1a8302, 0xbae07fff, 0x528246e7, 0x8e57140e, 0x3373f7bf, 0x8c9f8188, 0xa6fc4ee8, 0xc982b5a5,
0xa8c01db7, 0x579fc264, 0x67094f31, 0xf2bd3f5f, 0x40fff7c1, 0x1fb78dfc, 0x8e6bd2c1, 0x437be59b,
0x99b03dbf, 0xb5dbc64b, 0x638dc0e6, 0x55819d99, 0xa197c81c, 0x4a012d6e, 0xc5884a28, 0xccc36f71,
0xb843c213, 0x6c0743f1, 0x8309893c, 0x0feddd5f, 0x2f7fe850, 0xd7c07f7e, 0x02507fbf, 0x5afb9a04,
0xa747d2d0, 0x1651192e, 0xaf70bf3e, 0x58c31380, 0x5f98302e, 0x727cc3c4, 0x0a0fb402, 0x0f7fef82,
0x8c96fdad, 0x5d2c2aae, 0x8ee99a49, 0x50da88b8, 0x8427f4a0, 0x1eac5790, 0x796fb449, 0x8252dc15,
0xefbd7d9b, 0xa672597d, 0xada840d8, 0x45f54504, 0xfa5d7403, 0xe83ec305, 0x4f91751a, 0x925669c2,
0x23efe941, 0xa903f12e, 0x60270df2, 0x0276e4b6, 0x94fd6574, 0x927985b2, 0x8276dbcb, 0x02778176,
0xf8af918d, 0x4e48f79e, 0x8f616ddf, 0xe29d840e, 0x842f7d83, 0x340ce5c8, 0x96bbb682, 0x93b4b148,
0xef303cab, 0x984faf28, 0x779faf9b, 0x92dc560d, 0x224d1e20, 0x8437aa88, 0x7d29dc96, 0x2756d3dc,
0x8b907cee, 0xb51fd240, 0xe7c07ce3, 0xe566b4a1, 0xc3e9615e, 0x3cf8209d, 0x6094d1e3, 0xcd9ca341,
0x5c76460e, 0x00ea983b, 0xd4d67881, 0xfd47572c, 0xf76cedd9, 0xbda8229c, 0x127dadaa, 0x438a074e,
0x1f97c090, 0x081bdb8a, 0x93a07ebe, 0xb938ca15, 0x97b03cff, 0x3dc2c0f8, 0x8d1ab2ec, 0x64380e51,
0x68cc7bfb, 0xd90f2788, 0x12490181, 0x5de5ffd4, 0xdd7ef86a, 0x76a2e214, 0xb9a40368, 0x925d958f,
0x4b39fffa, 0xba39aee9, 0xa4ffd30b, 0xfaf7933b, 0x6d498623, 0x193cbcfa, 0x27627545, 0x825cf47a,
0x61bd8ba0, 0xd11e42d1, 0xcead04f4, 0x127ea392, 0x10428db7, 0x8272a972, 0x9270c4a8, 0x127de50b,
0x285ba1c8, 0x3c62f44f, 0x35c0eaa5, 0xe805d231, 0x428929fb, 0xb4fcdf82, 0x4fb66a53, 0x0e7dc15b,
0x1f081fab, 0x108618ae, 0xfcfd086d, 0xf9ff2889, 0x694bcc11, 0x236a5cae, 0x12deca4d, 0x2c3f8cc5,
0xd2d02dfe, 0xf8ef5896, 0xe4cf52da, 0x95155b67, 0x494a488c, 0xb9b6a80c, 0x5c8f82bc, 0x89d36b45,
0x3a609437, 0xec00c9a9, 0x44715253, 0x0a874b49, 0xd773bc40, 0x7c34671c, 0x02717ef6, 0x4feb5536,
0xa2d02fff, 0xd2bf60c4, 0xd43f03c0, 0x50b4ef6d, 0x07478cd1, 0x006e1888, 0xa2e53f55, 0xb9e6d4bc,
0xa2048016, 0x97573833, 0xd7207d67, 0xde0f8f3d, 0x72f87b33, 0xabcc4f33, 0x7688c55d, 0x7b00a6b0,
0x947b0001, 0x570075d2, 0xf9bb88f8, 0x8942019e, 0x4264a5ff, 0x856302e0, 0x72dbd92b, 0xee971b69,
0x6ea22fde, 0x5f08ae2b, 0xaf7a616d, 0xe5c98767, 0xcf1febd2, 0x61efc8c2, 0xf1ac2571, 0xcc8239c2,
0x67214cb8, 0xb1e583d1, 0xb7dc3e62, 0x7f10bdce, 0xf90a5c38, 0x0ff0443d, 0x606e6dc6, 0x60543a49,
0x5727c148, 0x2be98a1d, 0x8ab41738, 0x20e1be24, 0xaf96da0f, 0x68458425, 0x99833be5, 0x600d457d,
0x282f9350, 0x8334b362, 0xd91d1120, 0x2b6d8da0, 0x642b1e31, 0x9c305a00, 0x52bce688, 0x1b03588a,
0xf7baefd5, 0x4142ed9c, 0xa4315c11, 0x83323ec5, 0xdfef4636, 0xa133c501, 0xe9d3531c, 0xee353783,
},
{
0x9db30420, 0x1fb6e9de, 0xa7be7bef, 0xd273a298, 0x4a4f7bdb, 0x64ad8c57, 0x85510443, 0xfa020ed1,
0x7e287aff, 0xe60fb663, 0x095f35a1, 0x79ebf120, 0xfd059d43, 0x6497b7b1, 0xf3641f63, 0x241e4adf,
0x28147f5f, 0x4fa2b8cd, 0xc9430040, 0x0cc32220, 0xfdd30b30, 0xc0a5374f, 0x1d2d00d9, 0x24147b15,
0xee4d111a, 0x0fca5167, 0x71ff904c, 0x2d195ffe, 0x1a05645f, 0x0c13fefe, 0x081b08ca, 0x05170121,
0x80530100, 0xe83e5efe, 0xac9af4f8, 0x7fe72701, 0xd2b8ee5f, 0x06df4261, 0xbb9e9b8a, 0x7293ea25,
0xce84ffdf, 0xf5718801, 0x3dd64b04, 0xa26f263b, 0x7ed48400, 0x547eebe6, 0x446d4ca0, 0x6cf3d6f5,
0x2649abdf, 0xaea0c7f5, 0x36338cc1, 0x503f7e93, 0xd3772061, 0x11b638e1, 0x72500e03, 0xf80eb2bb,
0xabe0502e, 0xec8d77de, 0x57971e81, 0xe14f6746, 0xc9335400, 0x6920318f, 0x081dbb99, 0xffc304a5,
0x4d351805, 0x7f3d5ce3, 0xa6c866c6, 0x5d5bcca9, 0xdaec6fea, 0x9f926f91, 0x9f46222f, 0x3991467d,
0xa5bf6d8e, 0x1143c44f, 0x43958302, 0xd0214eeb, 0x022083b8, 0x3fb6180c, 0x18f8931e, 0x281658e6,
0x26486e3e, 0x8bd78a70, 0x7477e4c1, 0xb506e07c, 0xf32d0a25, 0x79098b02, 0xe4eabb81, 0x28123b23,
0x69dead38, 0x1574ca16, 0xdf871b62, 0x211c40b7, 0xa51a9ef9, 0x0014377b, 0x041e8ac8, 0x09114003,
0xbd59e4d2, 0xe3d156d5, 0x4fe876d5, 0x2f91a340, 0x557be8de, 0x00eae4a7, 0x0ce5c2ec, 0x4db4bba6,
0xe756bdff, 0xdd3369ac, 0xec17b035, 0x06572327, 0x99afc8b0, 0x56c8c391, 0x6b65811c, 0x5e146119,
0x6e85cb75, 0xbe07c002, 0xc2325577, 0x893ff4ec, 0x5bbfc92d, 0xd0ec3b25, 0xb7801ab7, 0x8d6d3b24,
0x20c763ef, 0xc366a5fc, 0x9c382880, 0x0ace3205, 0xaac9548a, 0xeca1d7c7, 0x041afa32, 0x1d16625a,
0x6701902c, 0x9b757a54, 0x31d477f7, 0x9126b031, 0x36cc6fdb, 0xc70b8b46, 0xd9e66a48, 0x56e55a79,
0x026a4ceb, 0x52437eff, 0x2f8f76b4, 0x0df980a5, 0x8674cde3, 0xedda04eb, 0x17a9be04, 0x2c18f4df,
0xb7747f9d, 0xab2af7b4, 0xefc34d20, 0x2e096b7c, 0x1741a254, 0xe5b6a035, 0x213d42f6, 0x2c1c7c26,
0x61c2f50f, 0x6552daf9, 0xd2c231f8, 0x25130f69, 0xd8167fa2, 0x0418f2c8, 0x001a96a6, 0x0d1526ab,
0x63315c21, 0x5e0a72ec, 0x49bafefd, 0x187908d9, 0x8d0dbd86, 0x311170a7, 0x3e9b640c, 0xcc3e10d7,
0xd5cad3b6, 0x0caec388, 0xf73001e1, 0x6c728aff, 0x71eae2a1, 0x1f9af36e, 0xcfcbd12f, 0xc1de8417,
0xac07be6b, 0xcb44a1d8, 0x8b9b0f56, 0x013988c3, 0xb1c52fca, 0xb4be31cd, 0xd8782806, 0x12a3a4e2,
0x6f7de532, 0x58fd7eb6, 0xd01ee900, 0x24adffc2, 0xf4990fc5, 0x9711aac5, 0x001d7b95, 0x82e5e7d2,
0x109873f6, 0x00613096, 0xc32d9521, 0xada121ff, 0x29908415, 0x7fbb977f, 0xaf9eb3db, 0x29c9ed2a,
0x5ce2a465, 0xa730f32c, 0xd0aa3fe8, 0x8a5cc091, 0xd49e2ce7, 0x0ce454a9, 0xd60acd86, 0x015f1919,
0x77079103, 0xdea03af6, 0x78a8565e, 0xdee356df, 0x21f05cbe, 0x8b75e387, 0xb3c50651, 0xb8a5c3ef,
0xd8eeb6d2, 0xe523be77, 0xc2154529, 0x2f69efdf, 0xafe67afb, 0xf470c4b2, 0xf3e0eb5b, 0xd6cc9876,
0x39e4460c, 0x1fda8538, 0x1987832f, 0xca007367, 0xa99144f8, 0x296b299e, 0x492fc295, 0x9266beab,
0xb5676e69, 0x9bd3ddda, 0xdf7e052f, 0xdb25701c, 0x1b5e51ee, 0xf65324e6, 0x6afce36c, 0x0316cc04,
0x8644213e, 0xb7dc59d0, 0x7965291f, 0xccd6fd43, 0x41823979, 0x932bcdf6, 0xb657c34d, 0x4edfd282,
0x7ae5290c, 0x3cb9536b, 0x851e20fe, 0x9833557e, 0x13ecf0b0, 0xd3ffb372, 0x3f85c5c1, 0x0aef7ed2,
},
{
0x7ec90c04, 0x2c6e74b9, 0x9b0e66df, 0xa6337911, 0xb86a7fff, 0x1dd358f5, 0x44dd9d44, 0x1731167f,
0x08fbf1fa, 0xe7f511cc, 0xd2051b00, 0x735aba00, 0x2ab722d8, 0x386381cb, 0xacf6243a, 0x69befd7a,
0xe6a2e77f, 0xf0c720cd, 0xc4494816, 0xccf5c180, 0x38851640, 0x15b0a848, 0xe68b18cb, 0x4caadeff,
0x5f480a01, 0x0412b2aa, 0x259814fc, 0x41d0efe2, 0x4e40b48d, 0x248eb6fb, 0x8dba1cfe, 0x41a99b02,
0x1a550a04, 0xba8f65cb, 0x7251f4e7, 0x95a51725, 0xc106ecd7, 0x97a5980a, 0xc539b9aa, 0x4d79fe6a,
0xf2f3f763, 0x68af8040, 0xed0c9e56, 0x11b4958b, 0xe1eb5a88, 0x8709e6b0, 0xd7e07156, 0x4e29fea7,
0x6366e52d, 0x02d1c000, 0xc4ac8e05, 0x9377f571, 0x0c05372a, 0x578535f2, 0x2261be02, 0xd642a0c9,
0xdf13a280, 0x74b55bd2, 0x682199c0, 0xd421e5ec, 0x53fb3ce8, 0xc8adedb3, 0x28a87fc9, 0x3d959981,
0x5c1ff900, 0xfe38d399, 0x0c4eff0b, 0x062407ea, 0xaa2f4fb1, 0x4fb96976, 0x90c79505, 0xb0a8a774,
0xef55a1ff, 0xe59ca2c2, 0xa6b62d27, 0xe66a4263, 0xdf65001f, 0x0ec50966, 0xdfdd55bc, 0x29de0655,
0x911e739a, 0x17af8975, 0x32c7911c, 0x89f89468, 0x0d01e980, 0x524755f4, 0x03b63cc9, 0x0cc844b2,
0xbcf3f0aa, 0x87ac36e9, 0xe53a7426, 0x01b3d82b, 0x1a9e7449, 0x64ee2d7e, 0xcddbb1da, 0x01c94910,
0xb868bf80, 0x0d26f3fd, 0x9342ede7, 0x04a5c284, 0x636737b6, 0x50f5b616, 0xf24766e3, 0x8eca36c1,
0x136e05db, 0xfef18391, 0xfb887a37, 0xd6e7f7d4, 0xc7fb7dc9, 0x3063fcdf, 0xb6f589de, 0xec2941da,
0x26e46695, 0xb7566419, 0xf654efc5, 0xd08d58b7, 0x48925401, 0xc1bacb7f, 0xe5ff550f, 0xb6083049,
0x5bb5d0e8, 0x87d72e5a, 0xab6a6ee1, 0x223a66ce, 0xc62bf3cd, 0x9e0885f9, 0x68cb3e47, 0x086c010f,
0xa21de820, 0xd18b69de, 0xf3f65777, 0xfa02c3f6, 0x407edac3, 0xcbb3d550, 0x1793084d, 0xb0d70eba,
0x0ab378d5, 0xd951fb0c, 0xded7da56, 0x4124bbe4, 0x94ca0b56, 0x0f5755d1, 0xe0e1e56e, 0x6184b5be,
0x580a249f, 0x94f74bc0, 0xe327888e, 0x9f7b5561, 0xc3dc0280, 0x05687715, 0x646c6bd7, 0x44904db3,
0x66b4f0a3, 0xc0f1648a, 0x697ed5af, 0x49e92ff6, 0x309e374f, 0x2cb6356a, 0x85808573, 0x4991f840,
0x76f0ae02, 0x083be84d, 0x28421c9a, 0x44489406, 0x736e4cb8, 0xc1092910, 0x8bc95fc6, 0x7d869cf4,
0x134f616f, 0x2e77118d, 0xb31b2be1, 0xaa90b472, 0x3ca5d717, 0x7d161bba, 0x9cad9010, 0xaf462ba2,
0x9fe459d2, 0x45d34559, 0xd9f2da13, 0xdbc65487, 0xf3e4f94e, 0x176d486f, 0x097c13ea, 0x631da5c7,
0x445f7382, 0x175683f4, 0xcdc66a97, 0x70be0288, 0xb3cdcf72, 0x6e5dd2f3, 0x20936079, 0x459b80a5,
0xbe60e2db, 0xa9c23101, 0xeba5315c, 0x224e42f2, 0x1c5c1572, 0xf6721b2c, 0x1ad2fff3, 0x8c25404e,
0x324ed72f, 0x4067b7fd, 0x0523138e, 0x5ca3bc78, 0xdc0fd66e, 0x75922283, 0x784d6b17, 0x58ebb16e,
0x44094f85, 0x3f481d87, 0xfcfeae7b, 0x77b5ff76, 0x8c2302bf, 0xaaf47556, 0x5f46b02a, 0x2b092801,
0x3d38f5f7, 0x0ca81f36, 0x52af4a8a, 0x66d5e7c0, 0xdf3b0874, 0x95055110, 0x1b5ad7a8, 0xf61ed5ad,
0x6cf6e479, 0x20758184, 0xd0cefa65, 0x88f7be58, 0x4a046826, 0x0ff6f8f3, 0xa09c7f70, 0x5346aba0,
0x5ce96c28, 0xe176eda3, 0x6bac307f, 0x376829d2, 0x85360fa9, 0x17e3fe2a, 0x24b79767, 0xf5a96b20,
0xd6cd2595, 0x68ff1ebf, 0x7555442c, 0xf19f06be, 0xf9e0659a, 0xeeb9491d, 0x34010718, 0xbb30cab8,
0xe822fe15, 0x88570983, 0x750e6249, 0xda627e55, 0x5e76ffa8, 0xb1534546, 0x6d47de08, 0xefe9e7d4,
},
{
0xf6fa8f9d, 0x2cac6ce1, 0x4ca34867, 0xe2337f7c, 0x95db08e7, 0x016843b4, 0xeced5cbc, 0x325553ac,
0xbf9f0960, 0xdfa1e2ed, 0x83f0579d, 0x63ed86b9, 0x1ab6a6b8, 0xde5ebe39, 0xf38ff732, 0x8989b138,
0x33f14961, 0xc01937bd, 0xf506c6da, 0xe4625e7e, 0xa308ea99, 0x4e23e33c, 0x79cbd7cc, 0x48a14367,
0xa3149619, 0xfec94bd5, 0xa114174a, 0xeaa01866, 0xa084db2d, 0x09a8486f, 0xa888614a, 0x2900af98,
0x01665991, 0xe1992863, 0xc8f30c60, 0x2e78ef3c, 0xd0d51932, 0xcf0fec14, 0xf7ca07d2, 0xd0a82072,
0xfd41197e, 0x9305a6b0, 0xe86be3da, 0x74bed3cd, 0x372da53c, 0x4c7f4448, 0xdab5d440, 0x6dba0ec3,
0x083919a7, 0x9fbaeed9, 0x49dbcfb0, 0x4e670c53, 0x5c3d9c01, 0x64bdb941, 0x2c0e636a, 0xba7dd9cd,
0xea6f7388, 0xe70bc762, 0x35f29adb, 0x5c4cdd8d, 0xf0d48d8c, 0xb88153e2, 0x08a19866, 0x1ae2eac8,
0x284caf89, 0xaa928223, 0x9334be53, 0x3b3a21bf, 0x16434be3, 0x9aea3906, 0xefe8c36e, 0xf890cdd9,
0x80226dae, 0xc340a4a3, 0xdf7e9c09, 0xa694a807, 0x5b7c5ecc, 0x221db3a6, 0x9a69a02f, 0x68818a54,
0xceb2296f, 0x53c0843a, 0xfe893655, 0x25bfe68a, 0xb4628abc, 0xcf222ebf, 0x25ac6f48, 0xa9a99387,
0x53bddb65, 0xe76ffbe7, 0xe967fd78, 0x0ba93563, 0x8e342bc1, 0xe8a11be9, 0x4980740d, 0xc8087dfc,
0x8de4bf99, 0xa11101a0, 0x7fd37975, 0xda5a26c0, 0xe81f994f, 0x9528cd89, 0xfd339fed, 0xb87834bf,
0x5f04456d, 0x22258698, 0xc9c4c83b, 0x2dc156be, 0x4f628daa, 0x57f55ec5, 0xe2220abe, 0xd2916ebf,
0x4ec75b95, 0x24f2c3c0, 0x42d15d99, 0xcd0d7fa0, 0x7b6e27ff, 0xa8dc8af0, 0x7345c106, 0xf41e232f,
0x35162386, 0xe6ea8926, 0x3333b094, 0x157ec6f2, 0x372b74af, 0x692573e4, 0xe9a9d848, 0xf3160289,
0x3a62ef1d, 0xa787e238, 0xf3a5f676, 0x74364853, 0x20951063, 0x4576698d, 0xb6fad407, 0x592af950,
0x36f73523, 0x4cfb6e87, 0x7da4cec0, 0x6c152daa, 0xcb0396a8, 0xc50dfe5d, 0xfcd707ab, 0x0921c42f,
0x89dff0bb, 0x5fe2be78, 0x448f4f33, 0x754613c9, 0x2b05d08d, 0x48b9d585, 0xdc049441, 0xc8098f9b,
0x7dede786, 0xc39a3373, 0x42410005, 0x6a091751, 0x0ef3c8a6, 0x890072d6, 0x28207682, 0xa9a9f7be,
0xbf32679d, 0xd45b5b75, 0xb353fd00, 0xcbb0e358, 0x830f220a, 0x1f8fb214, 0xd372cf08, 0xcc3c4a13,
0x8cf63166, 0x061c87be, 0x88c98f88, 0x6062e397, 0x47cf8e7a, 0xb6c85283, 0x3cc2acfb, 0x3fc06976,
0x4e8f0252, 0x64d8314d, 0xda3870e3, 0x1e665459, 0xc10908f0, 0x513021a5, 0x6c5b68b7, 0x822f8aa0,
0x3007cd3e, 0x74719eef, 0xdc872681, 0x073340d4, 0x7e432fd9, 0x0c5ec241, 0x8809286c, 0xf592d891,
0x08a930f6, 0x957ef305, 0xb7fbffbd, 0xc266e96f, 0x6fe4ac98, 0xb173ecc0, 0xbc60b42a, 0x953498da,
0xfba1ae12, 0x2d4bd736, 0x0f25faab, 0xa4f3fceb, 0xe2969123, 0x257f0c3d, 0x9348af49, 0x361400bc,
0xe8816f4a, 0x3814f200, 0xa3f94043, 0x9c7a54c2, 0xbc704f57, 0xda41e7f9, 0xc25ad33a, 0x54f4a084,
0xb17f5505, 0x59357cbe, 0xedbd15c8, 0x7f97c5ab, 0xba5ac7b5, 0xb6f6deaf, 0x3a479c3a, 0x5302da25,
0x653d7e6a, 0x54268d49, 0x51a477ea, 0x5017d55b, 0xd7d25d88, 0x44136c76, 0x0404a8c8, 0xb8e5a121,
0xb81a928a, 0x60ed5869, 0x97c55b96, 0xeaec991b, 0x29935913, 0x01fdb7f1, 0x088e8dfa, 0x9ab6f6f5,
0x3b4cbf9f, 0x4a5de3ab, 0xe6051d35, 0xa0e1d855, 0xd36b4cf1, 0xf544edeb, 0xb0e93524, 0xbebb8fbd,
0xa2d762cf, 0x49c92f54, 0x38b5f331, 0x7128a454, 0x48392905, 0xa65b1db8, 0x851c97bd, 0xd675cf2f,
},
{
0x85e04019, 0x332bf567, 0x662dbfff, 0xcfc65693, 0x2a8d7f6f, 0xab9bc912, 0xde6008a1, 0x2028da1f,
0x0227bce7, 0x4d642916, 0x18fac300, 0x50f18b82, 0x2cb2cb11, 0xb232e75c, 0x4b3695f2, 0xb28707de,
0xa05fbcf6, 0xcd4181e9, 0xe150210c, 0xe24ef1bd, 0xb168c381, 0xfde4e789, 0x5c79b0d8, 0x1e8bfd43,
0x4d495001, 0x38be4341, 0x913cee1d, 0x92a79c3f, 0x089766be, 0xbaeeadf4, 0x1286becf, 0xb6eacb19,
0x2660c200, 0x7565bde4, 0x64241f7a, 0x8248dca9, 0xc3b3ad66, 0x28136086, 0x0bd8dfa8, 0x356d1cf2,
0x107789be, 0xb3b2e9ce, 0x0502aa8f, 0x0bc0351e, 0x166bf52a, 0xeb12ff82, 0xe3486911, 0xd34d7516,
0x4e7b3aff, 0x5f43671b, 0x9cf6e037, 0x4981ac83, 0x334266ce, 0x8c9341b7, 0xd0d854c0, 0xcb3a6c88,
0x47bc2829, 0x4725ba37, 0xa66ad22b, 0x7ad61f1e, 0x0c5cbafa, 0x4437f107, 0xb6e79962, 0x42d2d816,
0x0a961288, 0xe1a5c06e, 0x13749e67, 0x72fc081a, 0xb1d139f7, 0xf9583745, 0xcf19df58, 0xbec3f756,
0xc06eba30, 0x07211b24, 0x45c28829, 0xc95e317f, 0xbc8ec511, 0x38bc46e9, 0xc6e6fa14, 0xbae8584a,
0xad4ebc46, 0x468f508b, 0x7829435f, 0xf124183b, 0x821dba9f, 0xaff60ff4, 0xea2c4e6d, 0x16e39264,
0x92544a8b, 0x009b4fc3, 0xaba68ced, 0x9ac96f78, 0x06a5b79a, 0xb2856e6e, 0x1aec3ca9, 0xbe838688,
0x0e0804e9, 0x55f1be56, 0xe7e5363b, 0xb3a1f25d, 0xf7debb85, 0x61fe033c, 0x16746233, 0x3c034c28,
0xda6d0c74, 0x79aac56c, 0x3ce4e1ad, 0x51f0c802, 0x98f8f35a, 0x1626a49f, 0xeed82b29, 0x1d382fe3,
0x0c4fb99a, 0xbb325778, 0x3ec6d97b, 0x6e77a6a9, 0xcb658b5c, 0xd45230c7, 0x2bd1408b, 0x60c03eb7,
0xb9068d78, 0xa33754f4, 0xf430c87d, 0xc8a71302, 0xb96d8c32, 0xebd4e7be, 0xbe8b9d2d, 0x7979fb06,
0xe7225308, 0x8b75cf77, 0x11ef8da4, 0xe083c858, 0x8d6b786f, 0x5a6317a6, 0xfa5cf7a0, 0x5dda0033,
0xf28ebfb0, 0xf5b9c310, 0xa0eac280, 0x08b9767a, 0xa3d9d2b0, 0x79d34217, 0x021a718d, 0x9ac6336a,
0x2711fd60, 0x438050e3, 0x069908a8, 0x3d7fedc4, 0x826d2bef, 0x4eeb8476, 0x488dcf25, 0x36c9d566,
0x28e74e41, 0xc2610aca, 0x3d49a9cf, 0xbae3b9df, 0xb65f8de6, 0x92aeaf64, 0x3ac7d5e6, 0x9ea80509,
0xf22b017d, 0xa4173f70, 0xdd1e16c3, 0x15e0d7f9, 0x50b1b887, 0x2b9f4fd5, 0x625aba82, 0x6a017962,
0x2ec01b9c, 0x15488aa9, 0xd716e740, 0x40055a2c, 0x93d29a22, 0xe32dbf9a, 0x058745b9, 0x3453dc1e,
0xd699296e, 0x496cff6f, 0x1c9f4986, 0xdfe2ed07, 0xb87242d1, 0x19de7eae, 0x053e561a, 0x15ad6f8c,
0x66626c1c, 0x7154c24c, 0xea082b2a, 0x93eb2939, 0x17dcb0f0, 0x58d4f2ae, 0x9ea294fb, 0x52cf564c,
0x9883fe66, 0x2ec40581, 0x763953c3, 0x01d6692e, 0xd3a0c108, 0xa1e7160e, 0xe4f2dfa6, 0x693ed285,
0x74904698, 0x4c2b0edd, 0x4f757656, 0x5d393378, 0xa132234f, 0x3d321c5d, 0xc3f5e194, 0x4b269301,
0xc79f022f, 0x3c997e7e, 0x5e4f9504, 0x3ffafbbd, 0x76f7ad0e, 0x296693f4, 0x3d1fce6f, 0xc61e45be,
0xd3b5ab34, 0xf72bf9b7, 0x1b0434c0, 0x4e72b567, 0x5592a33d, 0xb5229301, 0xcfd2a87f, 0x60aeb767,
0x1814386b, 0x30bcc33d, 0x38a0c07d, 0xfd1606f2, 0xc363519b, 0x589dd390, 0x5479f8e6, 0x1cb8d647,
0x97fd61a9, 0xea7759f4, 0x2d57539d, 0x569a58cf, 0xe84e63ad, 0x462e1b78, 0x6580f87e, 0xf3817914,
0x91da55f4, 0x40a230f3, 0xd1988f35, 0xb6e318d2, 0x3ffa50bc, 0x3d40f021, 0xc3c0bdae, 0x4958c24c,
0x518f36b2, 0x84b1d370, 0x0fedce83, 0x878ddada, 0xf2a279c7, 0x94e01be8, 0x90716f4b, 0x954b8aa3,
},
{
0xe216300d, 0xbbddfffc, 0xa7ebdabd, 0x35648095, 0x7789f8b7, 0xe6c1121b, 0x0e241600, 0x052ce8b5,
0x11a9cfb0, 0xe5952f11, 0xece7990a, 0x9386d174, 0x2a42931c, 0x76e38111, 0xb12def3a, 0x37ddddfc,
0xde9adeb1, 0x0a0cc32c, 0xbe197029, 0x84a00940, 0xbb243a0f, 0xb4d137cf, 0xb44e79f0, 0x049eedfd,
0x0b15a15d, 0x480d3168, 0x8bbbde5a, 0x669ded42, 0xc7ece831, 0x3f8f95e7, 0x72df191b, 0x7580330d,
0x94074251, 0x5c7dcdfa, 0xabbe6d63, 0xaa402164, 0xb301d40a, 0x02e7d1ca, 0x53571dae, 0x7a3182a2,
0x12a8ddec, 0xfdaa335d, 0x176f43e8, 0x71fb46d4, 0x38129022, 0xce949ad4, 0xb84769ad, 0x965bd862,
0x82f3d055, 0x66fb9767, 0x15b80b4e, 0x1d5b47a0, 0x4cfde06f, 0xc28ec4b8, 0x57e8726e, 0x647a78fc,
0x99865d44, 0x608bd593, 0x6c200e03, 0x39dc5ff6, 0x5d0b00a3, 0xae63aff2, 0x7e8bd632, 0x70108c0c,
0xbbd35049, 0x2998df04, 0x980cf42a, 0x9b6df491, 0x9e7edd53, 0x06918548, 0x58cb7e07, 0x3b74ef2e,
0x522fffb1, 0xd24708cc, 0x1c7e27cd, 0xa4eb215b, 0x3cf1d2e2, 0x19b47a38, 0x424f7618, 0x35856039,
0x9d17dee7, 0x27eb35e6, 0xc9aff67b, 0x36baf5b8, 0x09c467cd, 0xc18910b1, 0xe11dbf7b, 0x06cd1af8,
0x7170c608, 0x2d5e3354, 0xd4de495a, 0x64c6d006, 0xbcc0c62c, 0x3dd00db3, 0x708f8f34, 0x77d51b42,
0x264f620f, 0x24b8d2bf, 0x15c1b79e, 0x46a52564, 0xf8d7e54e, 0x3e378160, 0x7895cda5, 0x859c15a5,
0xe6459788, 0xc37bc75f, 0xdb07ba0c, 0x0676a3ab, 0x7f229b1e, 0x31842e7b, 0x24259fd7, 0xf8bef472,
0x835ffcb8, 0x6df4c1f2, 0x96f5b195, 0xfd0af0fc, 0xb0fe134c, 0xe2506d3d, 0x4f9b12ea, 0xf215f225,
0xa223736f, 0x9fb4c428, 0x25d04979, 0x34c713f8, 0xc4618187, 0xea7a6e98, 0x7cd16efc, 0x1436876c,
0xf1544107, 0xbedeee14, 0x56e9af27, 0xa04aa441, 0x3cf7c899, 0x92ecbae6, 0xdd67016d, 0x151682eb,
0xa842eedf, 0xfdba60b4, 0xf1907b75, 0x20e3030f, 0x24d8c29e, 0xe139673b, 0xefa63fb8, 0x71873054,
0xb6f2cf3b, 0x9f326442, 0xcb15a4cc, 0xb01a4504, 0xf1e47d8d, 0x844a1be5, 0xbae7dfdc, 0x42cbda70,
0xcd7dae0a, 0x57e85b7a, 0xd53f5af6, 0x20cf4d8c, 0xcea4d428, 0x79d130a4, 0x3486ebfb, 0x33d3cddc,
0x77853b53, 0x37effcb5, 0xc5068778, 0xe580b3e6, 0x4e68b8f4, 0xc5c8b37e, 0x0d809ea2, 0x398feb7c,
0x132a4f94, 0x43b7950e, 0x2fee7d1c, 0x223613bd, 0xdd06caa2, 0x37df932b, 0xc4248289, 0xacf3ebc3,
0x5715f6b7, 0xef3478dd, 0xf267616f, 0xc148cbe4, 0x9052815e, 0x5e410fab, 0xb48a2465, 0x2eda7fa4,
0xe87b40e4, 0xe98ea084, 0x5889e9e1, 0xefd390fc, 0xdd07d35b, 0xdb485694, 0x38d7e5b2, 0x57720101,
0x730edebc, 0x5b643113, 0x94917e4f, 0x503c2fba, 0x646f1282, 0x7523d24a, 0xe0779695, 0xf9c17a8f,
0x7a5b2121, 0xd187b896, 0x29263a4d, 0xba510cdf, 0x81f47c9f, 0xad1163ed, 0xea7b5965, 0x1a00726e,
0x11403092, 0x00da6d77, 0x4a0cdd61, 0xad1f4603, 0x605bdfb0, 0x9eedc364, 0x22ebe6a8, 0xcee7d28a,
0xa0e736a0, 0x5564a6b9, 0x10853209, 0xc7eb8f37, 0x2de705ca, 0x8951570f, 0xdf09822b, 0xbd691a6c,
0xaa12e4f2, 0x87451c0f, 0xe0f6a27a, 0x3ada4819, 0x4cf1764f, 0x0d771c2b, 0x67cdb156, 0x350d8384,
0x5938fa0f, 0x42399ef3, 0x36997b07, 0x0e84093d, 0x4aa93e61, 0x8360d87b, 0x1fa98b0c, 0x1149382c,
0xe97625a5, 0x0614d1b7, 0x0e25244b, 0x0c768347, 0x589e8d82, 0x0d2059d1, 0xa466bb1e, 0xf8da0a82,
0x04f19130, 0xba6e4ec0, 0x99265164, 0x1ee7230d, 0x50b2ad80, 0xeaee6801, 0x8db2a283, 0xea8bf59e,
},
}

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@ -0,0 +1,20 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This code was translated into a form compatible with 6a from the public
// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
// +build amd64,!gccgo,!appengine
DATA ·REDMASK51(SB)/8, $0x0007FFFFFFFFFFFF
GLOBL ·REDMASK51(SB), 8, $8
DATA ·_121666_213(SB)/8, $996687872
GLOBL ·_121666_213(SB), 8, $8
DATA ·_2P0(SB)/8, $0xFFFFFFFFFFFDA
GLOBL ·_2P0(SB), 8, $8
DATA ·_2P1234(SB)/8, $0xFFFFFFFFFFFFE
GLOBL ·_2P1234(SB), 8, $8

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@ -0,0 +1,88 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This code was translated into a form compatible with 6a from the public
// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
// +build amd64,!gccgo,!appengine
// func cswap(inout *[5]uint64, v uint64)
TEXT ·cswap(SB),7,$0
MOVQ inout+0(FP),DI
MOVQ v+8(FP),SI
CMPQ SI,$1
MOVQ 0(DI),SI
MOVQ 80(DI),DX
MOVQ 8(DI),CX
MOVQ 88(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,0(DI)
MOVQ DX,80(DI)
MOVQ CX,8(DI)
MOVQ R8,88(DI)
MOVQ 16(DI),SI
MOVQ 96(DI),DX
MOVQ 24(DI),CX
MOVQ 104(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,16(DI)
MOVQ DX,96(DI)
MOVQ CX,24(DI)
MOVQ R8,104(DI)
MOVQ 32(DI),SI
MOVQ 112(DI),DX
MOVQ 40(DI),CX
MOVQ 120(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,32(DI)
MOVQ DX,112(DI)
MOVQ CX,40(DI)
MOVQ R8,120(DI)
MOVQ 48(DI),SI
MOVQ 128(DI),DX
MOVQ 56(DI),CX
MOVQ 136(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,48(DI)
MOVQ DX,128(DI)
MOVQ CX,56(DI)
MOVQ R8,136(DI)
MOVQ 64(DI),SI
MOVQ 144(DI),DX
MOVQ 72(DI),CX
MOVQ 152(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,64(DI)
MOVQ DX,144(DI)
MOVQ CX,72(DI)
MOVQ R8,152(DI)
MOVQ DI,AX
MOVQ SI,DX
RET

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@ -0,0 +1,841 @@
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// We have a implementation in amd64 assembly so this code is only run on
// non-amd64 platforms. The amd64 assembly does not support gccgo.
// +build !amd64 gccgo appengine
package curve25519
// This code is a port of the public domain, "ref10" implementation of
// curve25519 from SUPERCOP 20130419 by D. J. Bernstein.
// fieldElement represents an element of the field GF(2^255 - 19). An element
// t, entries t[0]...t[9], represents the integer t[0]+2^26 t[1]+2^51 t[2]+2^77
// t[3]+2^102 t[4]+...+2^230 t[9]. Bounds on each t[i] vary depending on
// context.
type fieldElement [10]int32
func feZero(fe *fieldElement) {
for i := range fe {
fe[i] = 0
}
}
func feOne(fe *fieldElement) {
feZero(fe)
fe[0] = 1
}
func feAdd(dst, a, b *fieldElement) {
for i := range dst {
dst[i] = a[i] + b[i]
}
}
func feSub(dst, a, b *fieldElement) {
for i := range dst {
dst[i] = a[i] - b[i]
}
}
func feCopy(dst, src *fieldElement) {
for i := range dst {
dst[i] = src[i]
}
}
// feCSwap replaces (f,g) with (g,f) if b == 1; replaces (f,g) with (f,g) if b == 0.
//
// Preconditions: b in {0,1}.
func feCSwap(f, g *fieldElement, b int32) {
var x fieldElement
b = -b
for i := range x {
x[i] = b & (f[i] ^ g[i])
}
for i := range f {
f[i] ^= x[i]
}
for i := range g {
g[i] ^= x[i]
}
}
// load3 reads a 24-bit, little-endian value from in.
func load3(in []byte) int64 {
var r int64
r = int64(in[0])
r |= int64(in[1]) << 8
r |= int64(in[2]) << 16
return r
}
// load4 reads a 32-bit, little-endian value from in.
func load4(in []byte) int64 {
var r int64
r = int64(in[0])
r |= int64(in[1]) << 8
r |= int64(in[2]) << 16
r |= int64(in[3]) << 24
return r
}
func feFromBytes(dst *fieldElement, src *[32]byte) {
h0 := load4(src[:])
h1 := load3(src[4:]) << 6
h2 := load3(src[7:]) << 5
h3 := load3(src[10:]) << 3
h4 := load3(src[13:]) << 2
h5 := load4(src[16:])
h6 := load3(src[20:]) << 7
h7 := load3(src[23:]) << 5
h8 := load3(src[26:]) << 4
h9 := load3(src[29:]) << 2
var carry [10]int64
carry[9] = (h9 + 1<<24) >> 25
h0 += carry[9] * 19
h9 -= carry[9] << 25
carry[1] = (h1 + 1<<24) >> 25
h2 += carry[1]
h1 -= carry[1] << 25
carry[3] = (h3 + 1<<24) >> 25
h4 += carry[3]
h3 -= carry[3] << 25
carry[5] = (h5 + 1<<24) >> 25
h6 += carry[5]
h5 -= carry[5] << 25
carry[7] = (h7 + 1<<24) >> 25
h8 += carry[7]
h7 -= carry[7] << 25
carry[0] = (h0 + 1<<25) >> 26
h1 += carry[0]
h0 -= carry[0] << 26
carry[2] = (h2 + 1<<25) >> 26
h3 += carry[2]
h2 -= carry[2] << 26
carry[4] = (h4 + 1<<25) >> 26
h5 += carry[4]
h4 -= carry[4] << 26
carry[6] = (h6 + 1<<25) >> 26
h7 += carry[6]
h6 -= carry[6] << 26
carry[8] = (h8 + 1<<25) >> 26
h9 += carry[8]
h8 -= carry[8] << 26
dst[0] = int32(h0)
dst[1] = int32(h1)
dst[2] = int32(h2)
dst[3] = int32(h3)
dst[4] = int32(h4)
dst[5] = int32(h5)
dst[6] = int32(h6)
dst[7] = int32(h7)
dst[8] = int32(h8)
dst[9] = int32(h9)
}
// feToBytes marshals h to s.
// Preconditions:
// |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
//
// Write p=2^255-19; q=floor(h/p).
// Basic claim: q = floor(2^(-255)(h + 19 2^(-25)h9 + 2^(-1))).
//
// Proof:
// Have |h|<=p so |q|<=1 so |19^2 2^(-255) q|<1/4.
// Also have |h-2^230 h9|<2^230 so |19 2^(-255)(h-2^230 h9)|<1/4.
//
// Write y=2^(-1)-19^2 2^(-255)q-19 2^(-255)(h-2^230 h9).
// Then 0<y<1.
//
// Write r=h-pq.
// Have 0<=r<=p-1=2^255-20.
// Thus 0<=r+19(2^-255)r<r+19(2^-255)2^255<=2^255-1.
//
// Write x=r+19(2^-255)r+y.
// Then 0<x<2^255 so floor(2^(-255)x) = 0 so floor(q+2^(-255)x) = q.
//
// Have q+2^(-255)x = 2^(-255)(h + 19 2^(-25) h9 + 2^(-1))
// so floor(2^(-255)(h + 19 2^(-25) h9 + 2^(-1))) = q.
func feToBytes(s *[32]byte, h *fieldElement) {
var carry [10]int32
q := (19*h[9] + (1 << 24)) >> 25
q = (h[0] + q) >> 26
q = (h[1] + q) >> 25
q = (h[2] + q) >> 26
q = (h[3] + q) >> 25
q = (h[4] + q) >> 26
q = (h[5] + q) >> 25
q = (h[6] + q) >> 26
q = (h[7] + q) >> 25
q = (h[8] + q) >> 26
q = (h[9] + q) >> 25
// Goal: Output h-(2^255-19)q, which is between 0 and 2^255-20.
h[0] += 19 * q
// Goal: Output h-2^255 q, which is between 0 and 2^255-20.
carry[0] = h[0] >> 26
h[1] += carry[0]
h[0] -= carry[0] << 26
carry[1] = h[1] >> 25
h[2] += carry[1]
h[1] -= carry[1] << 25
carry[2] = h[2] >> 26
h[3] += carry[2]
h[2] -= carry[2] << 26
carry[3] = h[3] >> 25
h[4] += carry[3]
h[3] -= carry[3] << 25
carry[4] = h[4] >> 26
h[5] += carry[4]
h[4] -= carry[4] << 26
carry[5] = h[5] >> 25
h[6] += carry[5]
h[5] -= carry[5] << 25
carry[6] = h[6] >> 26
h[7] += carry[6]
h[6] -= carry[6] << 26
carry[7] = h[7] >> 25
h[8] += carry[7]
h[7] -= carry[7] << 25
carry[8] = h[8] >> 26
h[9] += carry[8]
h[8] -= carry[8] << 26
carry[9] = h[9] >> 25
h[9] -= carry[9] << 25
// h10 = carry9
// Goal: Output h[0]+...+2^255 h10-2^255 q, which is between 0 and 2^255-20.
// Have h[0]+...+2^230 h[9] between 0 and 2^255-1;
// evidently 2^255 h10-2^255 q = 0.
// Goal: Output h[0]+...+2^230 h[9].
s[0] = byte(h[0] >> 0)
s[1] = byte(h[0] >> 8)
s[2] = byte(h[0] >> 16)
s[3] = byte((h[0] >> 24) | (h[1] << 2))
s[4] = byte(h[1] >> 6)
s[5] = byte(h[1] >> 14)
s[6] = byte((h[1] >> 22) | (h[2] << 3))
s[7] = byte(h[2] >> 5)
s[8] = byte(h[2] >> 13)
s[9] = byte((h[2] >> 21) | (h[3] << 5))
s[10] = byte(h[3] >> 3)
s[11] = byte(h[3] >> 11)
s[12] = byte((h[3] >> 19) | (h[4] << 6))
s[13] = byte(h[4] >> 2)
s[14] = byte(h[4] >> 10)
s[15] = byte(h[4] >> 18)
s[16] = byte(h[5] >> 0)
s[17] = byte(h[5] >> 8)
s[18] = byte(h[5] >> 16)
s[19] = byte((h[5] >> 24) | (h[6] << 1))
s[20] = byte(h[6] >> 7)
s[21] = byte(h[6] >> 15)
s[22] = byte((h[6] >> 23) | (h[7] << 3))
s[23] = byte(h[7] >> 5)
s[24] = byte(h[7] >> 13)
s[25] = byte((h[7] >> 21) | (h[8] << 4))
s[26] = byte(h[8] >> 4)
s[27] = byte(h[8] >> 12)
s[28] = byte((h[8] >> 20) | (h[9] << 6))
s[29] = byte(h[9] >> 2)
s[30] = byte(h[9] >> 10)
s[31] = byte(h[9] >> 18)
}
// feMul calculates h = f * g
// Can overlap h with f or g.
//
// Preconditions:
// |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
// |g| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
//
// Postconditions:
// |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
//
// Notes on implementation strategy:
//
// Using schoolbook multiplication.
// Karatsuba would save a little in some cost models.
//
// Most multiplications by 2 and 19 are 32-bit precomputations;
// cheaper than 64-bit postcomputations.
//
// There is one remaining multiplication by 19 in the carry chain;
// one *19 precomputation can be merged into this,
// but the resulting data flow is considerably less clean.
//
// There are 12 carries below.
// 10 of them are 2-way parallelizable and vectorizable.
// Can get away with 11 carries, but then data flow is much deeper.
//
// With tighter constraints on inputs can squeeze carries into int32.
func feMul(h, f, g *fieldElement) {
f0 := f[0]
f1 := f[1]
f2 := f[2]
f3 := f[3]
f4 := f[4]
f5 := f[5]
f6 := f[6]
f7 := f[7]
f8 := f[8]
f9 := f[9]
g0 := g[0]
g1 := g[1]
g2 := g[2]
g3 := g[3]
g4 := g[4]
g5 := g[5]
g6 := g[6]
g7 := g[7]
g8 := g[8]
g9 := g[9]
g1_19 := 19 * g1 // 1.4*2^29
g2_19 := 19 * g2 // 1.4*2^30; still ok
g3_19 := 19 * g3
g4_19 := 19 * g4
g5_19 := 19 * g5
g6_19 := 19 * g6
g7_19 := 19 * g7
g8_19 := 19 * g8
g9_19 := 19 * g9
f1_2 := 2 * f1
f3_2 := 2 * f3
f5_2 := 2 * f5
f7_2 := 2 * f7
f9_2 := 2 * f9
f0g0 := int64(f0) * int64(g0)
f0g1 := int64(f0) * int64(g1)
f0g2 := int64(f0) * int64(g2)
f0g3 := int64(f0) * int64(g3)
f0g4 := int64(f0) * int64(g4)
f0g5 := int64(f0) * int64(g5)
f0g6 := int64(f0) * int64(g6)
f0g7 := int64(f0) * int64(g7)
f0g8 := int64(f0) * int64(g8)
f0g9 := int64(f0) * int64(g9)
f1g0 := int64(f1) * int64(g0)
f1g1_2 := int64(f1_2) * int64(g1)
f1g2 := int64(f1) * int64(g2)
f1g3_2 := int64(f1_2) * int64(g3)
f1g4 := int64(f1) * int64(g4)
f1g5_2 := int64(f1_2) * int64(g5)
f1g6 := int64(f1) * int64(g6)
f1g7_2 := int64(f1_2) * int64(g7)
f1g8 := int64(f1) * int64(g8)
f1g9_38 := int64(f1_2) * int64(g9_19)
f2g0 := int64(f2) * int64(g0)
f2g1 := int64(f2) * int64(g1)
f2g2 := int64(f2) * int64(g2)
f2g3 := int64(f2) * int64(g3)
f2g4 := int64(f2) * int64(g4)
f2g5 := int64(f2) * int64(g5)
f2g6 := int64(f2) * int64(g6)
f2g7 := int64(f2) * int64(g7)
f2g8_19 := int64(f2) * int64(g8_19)
f2g9_19 := int64(f2) * int64(g9_19)
f3g0 := int64(f3) * int64(g0)
f3g1_2 := int64(f3_2) * int64(g1)
f3g2 := int64(f3) * int64(g2)
f3g3_2 := int64(f3_2) * int64(g3)
f3g4 := int64(f3) * int64(g4)
f3g5_2 := int64(f3_2) * int64(g5)
f3g6 := int64(f3) * int64(g6)
f3g7_38 := int64(f3_2) * int64(g7_19)
f3g8_19 := int64(f3) * int64(g8_19)
f3g9_38 := int64(f3_2) * int64(g9_19)
f4g0 := int64(f4) * int64(g0)
f4g1 := int64(f4) * int64(g1)
f4g2 := int64(f4) * int64(g2)
f4g3 := int64(f4) * int64(g3)
f4g4 := int64(f4) * int64(g4)
f4g5 := int64(f4) * int64(g5)
f4g6_19 := int64(f4) * int64(g6_19)
f4g7_19 := int64(f4) * int64(g7_19)
f4g8_19 := int64(f4) * int64(g8_19)
f4g9_19 := int64(f4) * int64(g9_19)
f5g0 := int64(f5) * int64(g0)
f5g1_2 := int64(f5_2) * int64(g1)
f5g2 := int64(f5) * int64(g2)
f5g3_2 := int64(f5_2) * int64(g3)
f5g4 := int64(f5) * int64(g4)
f5g5_38 := int64(f5_2) * int64(g5_19)
f5g6_19 := int64(f5) * int64(g6_19)
f5g7_38 := int64(f5_2) * int64(g7_19)
f5g8_19 := int64(f5) * int64(g8_19)
f5g9_38 := int64(f5_2) * int64(g9_19)
f6g0 := int64(f6) * int64(g0)
f6g1 := int64(f6) * int64(g1)
f6g2 := int64(f6) * int64(g2)
f6g3 := int64(f6) * int64(g3)
f6g4_19 := int64(f6) * int64(g4_19)
f6g5_19 := int64(f6) * int64(g5_19)
f6g6_19 := int64(f6) * int64(g6_19)
f6g7_19 := int64(f6) * int64(g7_19)
f6g8_19 := int64(f6) * int64(g8_19)
f6g9_19 := int64(f6) * int64(g9_19)
f7g0 := int64(f7) * int64(g0)
f7g1_2 := int64(f7_2) * int64(g1)
f7g2 := int64(f7) * int64(g2)
f7g3_38 := int64(f7_2) * int64(g3_19)
f7g4_19 := int64(f7) * int64(g4_19)
f7g5_38 := int64(f7_2) * int64(g5_19)
f7g6_19 := int64(f7) * int64(g6_19)
f7g7_38 := int64(f7_2) * int64(g7_19)
f7g8_19 := int64(f7) * int64(g8_19)
f7g9_38 := int64(f7_2) * int64(g9_19)
f8g0 := int64(f8) * int64(g0)
f8g1 := int64(f8) * int64(g1)
f8g2_19 := int64(f8) * int64(g2_19)
f8g3_19 := int64(f8) * int64(g3_19)
f8g4_19 := int64(f8) * int64(g4_19)
f8g5_19 := int64(f8) * int64(g5_19)
f8g6_19 := int64(f8) * int64(g6_19)
f8g7_19 := int64(f8) * int64(g7_19)
f8g8_19 := int64(f8) * int64(g8_19)
f8g9_19 := int64(f8) * int64(g9_19)
f9g0 := int64(f9) * int64(g0)
f9g1_38 := int64(f9_2) * int64(g1_19)
f9g2_19 := int64(f9) * int64(g2_19)
f9g3_38 := int64(f9_2) * int64(g3_19)
f9g4_19 := int64(f9) * int64(g4_19)
f9g5_38 := int64(f9_2) * int64(g5_19)
f9g6_19 := int64(f9) * int64(g6_19)
f9g7_38 := int64(f9_2) * int64(g7_19)
f9g8_19 := int64(f9) * int64(g8_19)
f9g9_38 := int64(f9_2) * int64(g9_19)
h0 := f0g0 + f1g9_38 + f2g8_19 + f3g7_38 + f4g6_19 + f5g5_38 + f6g4_19 + f7g3_38 + f8g2_19 + f9g1_38
h1 := f0g1 + f1g0 + f2g9_19 + f3g8_19 + f4g7_19 + f5g6_19 + f6g5_19 + f7g4_19 + f8g3_19 + f9g2_19
h2 := f0g2 + f1g1_2 + f2g0 + f3g9_38 + f4g8_19 + f5g7_38 + f6g6_19 + f7g5_38 + f8g4_19 + f9g3_38
h3 := f0g3 + f1g2 + f2g1 + f3g0 + f4g9_19 + f5g8_19 + f6g7_19 + f7g6_19 + f8g5_19 + f9g4_19
h4 := f0g4 + f1g3_2 + f2g2 + f3g1_2 + f4g0 + f5g9_38 + f6g8_19 + f7g7_38 + f8g6_19 + f9g5_38
h5 := f0g5 + f1g4 + f2g3 + f3g2 + f4g1 + f5g0 + f6g9_19 + f7g8_19 + f8g7_19 + f9g6_19
h6 := f0g6 + f1g5_2 + f2g4 + f3g3_2 + f4g2 + f5g1_2 + f6g0 + f7g9_38 + f8g8_19 + f9g7_38
h7 := f0g7 + f1g6 + f2g5 + f3g4 + f4g3 + f5g2 + f6g1 + f7g0 + f8g9_19 + f9g8_19
h8 := f0g8 + f1g7_2 + f2g6 + f3g5_2 + f4g4 + f5g3_2 + f6g2 + f7g1_2 + f8g0 + f9g9_38
h9 := f0g9 + f1g8 + f2g7 + f3g6 + f4g5 + f5g4 + f6g3 + f7g2 + f8g1 + f9g0
var carry [10]int64
// |h0| <= (1.1*1.1*2^52*(1+19+19+19+19)+1.1*1.1*2^50*(38+38+38+38+38))
// i.e. |h0| <= 1.2*2^59; narrower ranges for h2, h4, h6, h8
// |h1| <= (1.1*1.1*2^51*(1+1+19+19+19+19+19+19+19+19))
// i.e. |h1| <= 1.5*2^58; narrower ranges for h3, h5, h7, h9
carry[0] = (h0 + (1 << 25)) >> 26
h1 += carry[0]
h0 -= carry[0] << 26
carry[4] = (h4 + (1 << 25)) >> 26
h5 += carry[4]
h4 -= carry[4] << 26
// |h0| <= 2^25
// |h4| <= 2^25
// |h1| <= 1.51*2^58
// |h5| <= 1.51*2^58
carry[1] = (h1 + (1 << 24)) >> 25
h2 += carry[1]
h1 -= carry[1] << 25
carry[5] = (h5 + (1 << 24)) >> 25
h6 += carry[5]
h5 -= carry[5] << 25
// |h1| <= 2^24; from now on fits into int32
// |h5| <= 2^24; from now on fits into int32
// |h2| <= 1.21*2^59
// |h6| <= 1.21*2^59
carry[2] = (h2 + (1 << 25)) >> 26
h3 += carry[2]
h2 -= carry[2] << 26
carry[6] = (h6 + (1 << 25)) >> 26
h7 += carry[6]
h6 -= carry[6] << 26
// |h2| <= 2^25; from now on fits into int32 unchanged
// |h6| <= 2^25; from now on fits into int32 unchanged
// |h3| <= 1.51*2^58
// |h7| <= 1.51*2^58
carry[3] = (h3 + (1 << 24)) >> 25
h4 += carry[3]
h3 -= carry[3] << 25
carry[7] = (h7 + (1 << 24)) >> 25
h8 += carry[7]
h7 -= carry[7] << 25
// |h3| <= 2^24; from now on fits into int32 unchanged
// |h7| <= 2^24; from now on fits into int32 unchanged
// |h4| <= 1.52*2^33
// |h8| <= 1.52*2^33
carry[4] = (h4 + (1 << 25)) >> 26
h5 += carry[4]
h4 -= carry[4] << 26
carry[8] = (h8 + (1 << 25)) >> 26
h9 += carry[8]
h8 -= carry[8] << 26
// |h4| <= 2^25; from now on fits into int32 unchanged
// |h8| <= 2^25; from now on fits into int32 unchanged
// |h5| <= 1.01*2^24
// |h9| <= 1.51*2^58
carry[9] = (h9 + (1 << 24)) >> 25
h0 += carry[9] * 19
h9 -= carry[9] << 25
// |h9| <= 2^24; from now on fits into int32 unchanged
// |h0| <= 1.8*2^37
carry[0] = (h0 + (1 << 25)) >> 26
h1 += carry[0]
h0 -= carry[0] << 26
// |h0| <= 2^25; from now on fits into int32 unchanged
// |h1| <= 1.01*2^24
h[0] = int32(h0)
h[1] = int32(h1)
h[2] = int32(h2)
h[3] = int32(h3)
h[4] = int32(h4)
h[5] = int32(h5)
h[6] = int32(h6)
h[7] = int32(h7)
h[8] = int32(h8)
h[9] = int32(h9)
}
// feSquare calculates h = f*f. Can overlap h with f.
//
// Preconditions:
// |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
//
// Postconditions:
// |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
func feSquare(h, f *fieldElement) {
f0 := f[0]
f1 := f[1]
f2 := f[2]
f3 := f[3]
f4 := f[4]
f5 := f[5]
f6 := f[6]
f7 := f[7]
f8 := f[8]
f9 := f[9]
f0_2 := 2 * f0
f1_2 := 2 * f1
f2_2 := 2 * f2
f3_2 := 2 * f3
f4_2 := 2 * f4
f5_2 := 2 * f5
f6_2 := 2 * f6
f7_2 := 2 * f7
f5_38 := 38 * f5 // 1.31*2^30
f6_19 := 19 * f6 // 1.31*2^30
f7_38 := 38 * f7 // 1.31*2^30
f8_19 := 19 * f8 // 1.31*2^30
f9_38 := 38 * f9 // 1.31*2^30
f0f0 := int64(f0) * int64(f0)
f0f1_2 := int64(f0_2) * int64(f1)
f0f2_2 := int64(f0_2) * int64(f2)
f0f3_2 := int64(f0_2) * int64(f3)
f0f4_2 := int64(f0_2) * int64(f4)
f0f5_2 := int64(f0_2) * int64(f5)
f0f6_2 := int64(f0_2) * int64(f6)
f0f7_2 := int64(f0_2) * int64(f7)
f0f8_2 := int64(f0_2) * int64(f8)
f0f9_2 := int64(f0_2) * int64(f9)
f1f1_2 := int64(f1_2) * int64(f1)
f1f2_2 := int64(f1_2) * int64(f2)
f1f3_4 := int64(f1_2) * int64(f3_2)
f1f4_2 := int64(f1_2) * int64(f4)
f1f5_4 := int64(f1_2) * int64(f5_2)
f1f6_2 := int64(f1_2) * int64(f6)
f1f7_4 := int64(f1_2) * int64(f7_2)
f1f8_2 := int64(f1_2) * int64(f8)
f1f9_76 := int64(f1_2) * int64(f9_38)
f2f2 := int64(f2) * int64(f2)
f2f3_2 := int64(f2_2) * int64(f3)
f2f4_2 := int64(f2_2) * int64(f4)
f2f5_2 := int64(f2_2) * int64(f5)
f2f6_2 := int64(f2_2) * int64(f6)
f2f7_2 := int64(f2_2) * int64(f7)
f2f8_38 := int64(f2_2) * int64(f8_19)
f2f9_38 := int64(f2) * int64(f9_38)
f3f3_2 := int64(f3_2) * int64(f3)
f3f4_2 := int64(f3_2) * int64(f4)
f3f5_4 := int64(f3_2) * int64(f5_2)
f3f6_2 := int64(f3_2) * int64(f6)
f3f7_76 := int64(f3_2) * int64(f7_38)
f3f8_38 := int64(f3_2) * int64(f8_19)
f3f9_76 := int64(f3_2) * int64(f9_38)
f4f4 := int64(f4) * int64(f4)
f4f5_2 := int64(f4_2) * int64(f5)
f4f6_38 := int64(f4_2) * int64(f6_19)
f4f7_38 := int64(f4) * int64(f7_38)
f4f8_38 := int64(f4_2) * int64(f8_19)
f4f9_38 := int64(f4) * int64(f9_38)
f5f5_38 := int64(f5) * int64(f5_38)
f5f6_38 := int64(f5_2) * int64(f6_19)
f5f7_76 := int64(f5_2) * int64(f7_38)
f5f8_38 := int64(f5_2) * int64(f8_19)
f5f9_76 := int64(f5_2) * int64(f9_38)
f6f6_19 := int64(f6) * int64(f6_19)
f6f7_38 := int64(f6) * int64(f7_38)
f6f8_38 := int64(f6_2) * int64(f8_19)
f6f9_38 := int64(f6) * int64(f9_38)
f7f7_38 := int64(f7) * int64(f7_38)
f7f8_38 := int64(f7_2) * int64(f8_19)
f7f9_76 := int64(f7_2) * int64(f9_38)
f8f8_19 := int64(f8) * int64(f8_19)
f8f9_38 := int64(f8) * int64(f9_38)
f9f9_38 := int64(f9) * int64(f9_38)
h0 := f0f0 + f1f9_76 + f2f8_38 + f3f7_76 + f4f6_38 + f5f5_38
h1 := f0f1_2 + f2f9_38 + f3f8_38 + f4f7_38 + f5f6_38
h2 := f0f2_2 + f1f1_2 + f3f9_76 + f4f8_38 + f5f7_76 + f6f6_19
h3 := f0f3_2 + f1f2_2 + f4f9_38 + f5f8_38 + f6f7_38
h4 := f0f4_2 + f1f3_4 + f2f2 + f5f9_76 + f6f8_38 + f7f7_38
h5 := f0f5_2 + f1f4_2 + f2f3_2 + f6f9_38 + f7f8_38
h6 := f0f6_2 + f1f5_4 + f2f4_2 + f3f3_2 + f7f9_76 + f8f8_19
h7 := f0f7_2 + f1f6_2 + f2f5_2 + f3f4_2 + f8f9_38
h8 := f0f8_2 + f1f7_4 + f2f6_2 + f3f5_4 + f4f4 + f9f9_38
h9 := f0f9_2 + f1f8_2 + f2f7_2 + f3f6_2 + f4f5_2
var carry [10]int64
carry[0] = (h0 + (1 << 25)) >> 26
h1 += carry[0]
h0 -= carry[0] << 26
carry[4] = (h4 + (1 << 25)) >> 26
h5 += carry[4]
h4 -= carry[4] << 26
carry[1] = (h1 + (1 << 24)) >> 25
h2 += carry[1]
h1 -= carry[1] << 25
carry[5] = (h5 + (1 << 24)) >> 25
h6 += carry[5]
h5 -= carry[5] << 25
carry[2] = (h2 + (1 << 25)) >> 26
h3 += carry[2]
h2 -= carry[2] << 26
carry[6] = (h6 + (1 << 25)) >> 26
h7 += carry[6]
h6 -= carry[6] << 26
carry[3] = (h3 + (1 << 24)) >> 25
h4 += carry[3]
h3 -= carry[3] << 25
carry[7] = (h7 + (1 << 24)) >> 25
h8 += carry[7]
h7 -= carry[7] << 25
carry[4] = (h4 + (1 << 25)) >> 26
h5 += carry[4]
h4 -= carry[4] << 26
carry[8] = (h8 + (1 << 25)) >> 26
h9 += carry[8]
h8 -= carry[8] << 26
carry[9] = (h9 + (1 << 24)) >> 25
h0 += carry[9] * 19
h9 -= carry[9] << 25
carry[0] = (h0 + (1 << 25)) >> 26
h1 += carry[0]
h0 -= carry[0] << 26
h[0] = int32(h0)
h[1] = int32(h1)
h[2] = int32(h2)
h[3] = int32(h3)
h[4] = int32(h4)
h[5] = int32(h5)
h[6] = int32(h6)
h[7] = int32(h7)
h[8] = int32(h8)
h[9] = int32(h9)
}
// feMul121666 calculates h = f * 121666. Can overlap h with f.
//
// Preconditions:
// |f| bounded by 1.1*2^26,1.1*2^25,1.1*2^26,1.1*2^25,etc.
//
// Postconditions:
// |h| bounded by 1.1*2^25,1.1*2^24,1.1*2^25,1.1*2^24,etc.
func feMul121666(h, f *fieldElement) {
h0 := int64(f[0]) * 121666
h1 := int64(f[1]) * 121666
h2 := int64(f[2]) * 121666
h3 := int64(f[3]) * 121666
h4 := int64(f[4]) * 121666
h5 := int64(f[5]) * 121666
h6 := int64(f[6]) * 121666
h7 := int64(f[7]) * 121666
h8 := int64(f[8]) * 121666
h9 := int64(f[9]) * 121666
var carry [10]int64
carry[9] = (h9 + (1 << 24)) >> 25
h0 += carry[9] * 19
h9 -= carry[9] << 25
carry[1] = (h1 + (1 << 24)) >> 25
h2 += carry[1]
h1 -= carry[1] << 25
carry[3] = (h3 + (1 << 24)) >> 25
h4 += carry[3]
h3 -= carry[3] << 25
carry[5] = (h5 + (1 << 24)) >> 25
h6 += carry[5]
h5 -= carry[5] << 25
carry[7] = (h7 + (1 << 24)) >> 25
h8 += carry[7]
h7 -= carry[7] << 25
carry[0] = (h0 + (1 << 25)) >> 26
h1 += carry[0]
h0 -= carry[0] << 26
carry[2] = (h2 + (1 << 25)) >> 26
h3 += carry[2]
h2 -= carry[2] << 26
carry[4] = (h4 + (1 << 25)) >> 26
h5 += carry[4]
h4 -= carry[4] << 26
carry[6] = (h6 + (1 << 25)) >> 26
h7 += carry[6]
h6 -= carry[6] << 26
carry[8] = (h8 + (1 << 25)) >> 26
h9 += carry[8]
h8 -= carry[8] << 26
h[0] = int32(h0)
h[1] = int32(h1)
h[2] = int32(h2)
h[3] = int32(h3)
h[4] = int32(h4)
h[5] = int32(h5)
h[6] = int32(h6)
h[7] = int32(h7)
h[8] = int32(h8)
h[9] = int32(h9)
}
// feInvert sets out = z^-1.
func feInvert(out, z *fieldElement) {
var t0, t1, t2, t3 fieldElement
var i int
feSquare(&t0, z)
for i = 1; i < 1; i++ {
feSquare(&t0, &t0)
}
feSquare(&t1, &t0)
for i = 1; i < 2; i++ {
feSquare(&t1, &t1)
}
feMul(&t1, z, &t1)
feMul(&t0, &t0, &t1)
feSquare(&t2, &t0)
for i = 1; i < 1; i++ {
feSquare(&t2, &t2)
}
feMul(&t1, &t1, &t2)
feSquare(&t2, &t1)
for i = 1; i < 5; i++ {
feSquare(&t2, &t2)
}
feMul(&t1, &t2, &t1)
feSquare(&t2, &t1)
for i = 1; i < 10; i++ {
feSquare(&t2, &t2)
}
feMul(&t2, &t2, &t1)
feSquare(&t3, &t2)
for i = 1; i < 20; i++ {
feSquare(&t3, &t3)
}
feMul(&t2, &t3, &t2)
feSquare(&t2, &t2)
for i = 1; i < 10; i++ {
feSquare(&t2, &t2)
}
feMul(&t1, &t2, &t1)
feSquare(&t2, &t1)
for i = 1; i < 50; i++ {
feSquare(&t2, &t2)
}
feMul(&t2, &t2, &t1)
feSquare(&t3, &t2)
for i = 1; i < 100; i++ {
feSquare(&t3, &t3)
}
feMul(&t2, &t3, &t2)
feSquare(&t2, &t2)
for i = 1; i < 50; i++ {
feSquare(&t2, &t2)
}
feMul(&t1, &t2, &t1)
feSquare(&t1, &t1)
for i = 1; i < 5; i++ {
feSquare(&t1, &t1)
}
feMul(out, &t1, &t0)
}
func scalarMult(out, in, base *[32]byte) {
var e [32]byte
copy(e[:], in[:])
e[0] &= 248
e[31] &= 127
e[31] |= 64
var x1, x2, z2, x3, z3, tmp0, tmp1 fieldElement
feFromBytes(&x1, base)
feOne(&x2)
feCopy(&x3, &x1)
feOne(&z3)
swap := int32(0)
for pos := 254; pos >= 0; pos-- {
b := e[pos/8] >> uint(pos&7)
b &= 1
swap ^= int32(b)
feCSwap(&x2, &x3, swap)
feCSwap(&z2, &z3, swap)
swap = int32(b)
feSub(&tmp0, &x3, &z3)
feSub(&tmp1, &x2, &z2)
feAdd(&x2, &x2, &z2)
feAdd(&z2, &x3, &z3)
feMul(&z3, &tmp0, &x2)
feMul(&z2, &z2, &tmp1)
feSquare(&tmp0, &tmp1)
feSquare(&tmp1, &x2)
feAdd(&x3, &z3, &z2)
feSub(&z2, &z3, &z2)
feMul(&x2, &tmp1, &tmp0)
feSub(&tmp1, &tmp1, &tmp0)
feSquare(&z2, &z2)
feMul121666(&z3, &tmp1)
feSquare(&x3, &x3)
feAdd(&tmp0, &tmp0, &z3)
feMul(&z3, &x1, &z2)
feMul(&z2, &tmp1, &tmp0)
}
feCSwap(&x2, &x3, swap)
feCSwap(&z2, &z3, swap)
feInvert(&z2, &z2)
feMul(&x2, &x2, &z2)
feToBytes(out, &x2)
}

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package curve25519
import (
"crypto/elliptic"
"math/big"
"sync"
)
var cv25519 cv25519Curve
type cv25519Curve struct {
*elliptic.CurveParams
}
func copyReverse(dst []byte, src []byte) {
// Curve 25519 multiplication functions expect scalars in reverse
// order than PGP. To keep the curve25519Curve type consistent
// with other curves, we reverse it here.
for i, j := 0, len(src)-1; j >= 0; i, j = i+1, j-1 {
dst[i] = src[j]
}
}
func (cv25519Curve) ScalarMult(x1, y1 *big.Int, scalar []byte) (x, y *big.Int) {
// Assume y1 is 0 with cv25519.
var dst [32]byte
var x1Bytes [32]byte
var scalarBytes [32]byte
copy(x1Bytes[:], x1.Bytes()[:32])
copyReverse(scalarBytes[:], scalar[:32])
scalarMult(&dst, &scalarBytes, &x1Bytes)
x = new(big.Int).SetBytes(dst[:])
y = new(big.Int)
return x, y
}
func (cv25519Curve) ScalarBaseMult(scalar []byte) (x, y *big.Int) {
var dst [32]byte
var scalarBytes [32]byte
copyReverse(scalarBytes[:], scalar[:32])
scalarMult(&dst, &scalarBytes, &basePoint)
x = new(big.Int).SetBytes(dst[:])
y = new(big.Int)
return x, y
}
func (cv25519Curve) IsOnCurve(bigX, bigY *big.Int) bool {
return bigY.Sign() == 0 // bigY == 0 ?
}
// More information about 0x40 point format:
// https://tools.ietf.org/html/draft-koch-eddsa-for-openpgp-00#section-3
// In addition to uncompressed point format described here:
// https://tools.ietf.org/html/rfc6637#section-6
func (cv25519Curve) MarshalType40(x, y *big.Int) []byte {
byteLen := 32
ret := make([]byte, 1+byteLen)
ret[0] = 0x40
xBytes := x.Bytes()
copy(ret[1+byteLen-len(xBytes):], xBytes)
return ret
}
func (cv25519Curve) UnmarshalType40(data []byte) (x, y *big.Int) {
if len(data) != 1+32 {
return nil, nil
}
if data[0] != 0x40 {
return nil, nil
}
x = new(big.Int).SetBytes(data[1:])
// Any x is a valid curve point.
return x, new(big.Int)
}
// ToCurve25519 casts given elliptic.Curve type to Curve25519 type, or
// returns nil, false if cast was unsuccessful.
func ToCurve25519(cv elliptic.Curve) (cv25519Curve, bool) {
cv2, ok := cv.(cv25519Curve)
return cv2, ok
}
func initCv25519() {
cv25519.CurveParams = &elliptic.CurveParams{Name: "Curve 25519"}
// Some code relies on these parameters being available for
// checking Curve coordinate length. They should not be used
// directly for any calculations.
cv25519.P, _ = new (big.Int).SetString("7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed", 16)
cv25519.N, _ = new (big.Int).SetString("1000000000000000000000000000000014def9dea2f79cd65812631a5cf5d3ed", 16)
cv25519.Gx, _ = new (big.Int).SetString("9", 16)
cv25519.Gy, _ = new (big.Int).SetString("20ae19a1b8a086b4e01edd2c7748d14c923d4d7e6d7c61b229e9c5a27eced3d9", 16)
cv25519.BitSize = 256
}
var initonce sync.Once
// Cv25519 returns a Curve which (partially) implements Cv25519. Only
// ScalarMult and ScalarBaseMult are valid for this curve. Add and
// Double should not be used.
func Cv25519() elliptic.Curve {
initonce.Do(initCv25519)
return cv25519
}
func (curve cv25519Curve) Params() *elliptic.CurveParams {
return curve.CurveParams
}

23
vendor/github.com/keybase/go-crypto/curve25519/doc.go generated vendored Normal file
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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package curve25519 provides an implementation of scalar multiplication on
// the elliptic curve known as curve25519. See http://cr.yp.to/ecdh.html
package curve25519
// basePoint is the x coordinate of the generator of the curve.
var basePoint = [32]byte{9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
// ScalarMult sets dst to the product in*base where dst and base are the x
// coordinates of group points and all values are in little-endian form.
func ScalarMult(dst, in, base *[32]byte) {
scalarMult(dst, in, base)
}
// ScalarBaseMult sets dst to the product in*base where dst and base are the x
// coordinates of group points, base is the standard generator and all values
// are in little-endian form.
func ScalarBaseMult(dst, in *[32]byte) {
ScalarMult(dst, in, &basePoint)
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This code was translated into a form compatible with 6a from the public
// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
// +build amd64,!gccgo,!appengine
// func freeze(inout *[5]uint64)
TEXT ·freeze(SB),7,$96-8
MOVQ inout+0(FP), DI
MOVQ SP,R11
MOVQ $31,CX
NOTQ CX
ANDQ CX,SP
ADDQ $32,SP
MOVQ R11,0(SP)
MOVQ R12,8(SP)
MOVQ R13,16(SP)
MOVQ R14,24(SP)
MOVQ R15,32(SP)
MOVQ BX,40(SP)
MOVQ BP,48(SP)
MOVQ 0(DI),SI
MOVQ 8(DI),DX
MOVQ 16(DI),CX
MOVQ 24(DI),R8
MOVQ 32(DI),R9
MOVQ ·REDMASK51(SB),AX
MOVQ AX,R10
SUBQ $18,R10
MOVQ $3,R11
REDUCELOOP:
MOVQ SI,R12
SHRQ $51,R12
ANDQ AX,SI
ADDQ R12,DX
MOVQ DX,R12
SHRQ $51,R12
ANDQ AX,DX
ADDQ R12,CX
MOVQ CX,R12
SHRQ $51,R12
ANDQ AX,CX
ADDQ R12,R8
MOVQ R8,R12
SHRQ $51,R12
ANDQ AX,R8
ADDQ R12,R9
MOVQ R9,R12
SHRQ $51,R12
ANDQ AX,R9
IMUL3Q $19,R12,R12
ADDQ R12,SI
SUBQ $1,R11
JA REDUCELOOP
MOVQ $1,R12
CMPQ R10,SI
CMOVQLT R11,R12
CMPQ AX,DX
CMOVQNE R11,R12
CMPQ AX,CX
CMOVQNE R11,R12
CMPQ AX,R8
CMOVQNE R11,R12
CMPQ AX,R9
CMOVQNE R11,R12
NEGQ R12
ANDQ R12,AX
ANDQ R12,R10
SUBQ R10,SI
SUBQ AX,DX
SUBQ AX,CX
SUBQ AX,R8
SUBQ AX,R9
MOVQ SI,0(DI)
MOVQ DX,8(DI)
MOVQ CX,16(DI)
MOVQ R8,24(DI)
MOVQ R9,32(DI)
MOVQ 0(SP),R11
MOVQ 8(SP),R12
MOVQ 16(SP),R13
MOVQ 24(SP),R14
MOVQ 32(SP),R15
MOVQ 40(SP),BX
MOVQ 48(SP),BP
MOVQ R11,SP
MOVQ DI,AX
MOVQ SI,DX
RET

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build amd64,!gccgo,!appengine
package curve25519
// These functions are implemented in the .s files. The names of the functions
// in the rest of the file are also taken from the SUPERCOP sources to help
// people following along.
//go:noescape
func cswap(inout *[5]uint64, v uint64)
//go:noescape
func ladderstep(inout *[5][5]uint64)
//go:noescape
func freeze(inout *[5]uint64)
//go:noescape
func mul(dest, a, b *[5]uint64)
//go:noescape
func square(out, in *[5]uint64)
// mladder uses a Montgomery ladder to calculate (xr/zr) *= s.
func mladder(xr, zr *[5]uint64, s *[32]byte) {
var work [5][5]uint64
work[0] = *xr
setint(&work[1], 1)
setint(&work[2], 0)
work[3] = *xr
setint(&work[4], 1)
j := uint(6)
var prevbit byte
for i := 31; i >= 0; i-- {
for j < 8 {
bit := ((*s)[i] >> j) & 1
swap := bit ^ prevbit
prevbit = bit
cswap(&work[1], uint64(swap))
ladderstep(&work)
j--
}
j = 7
}
*xr = work[1]
*zr = work[2]
}
func scalarMult(out, in, base *[32]byte) {
var e [32]byte
copy(e[:], (*in)[:])
e[0] &= 248
e[31] &= 127
e[31] |= 64
var t, z [5]uint64
unpack(&t, base)
mladder(&t, &z, &e)
invert(&z, &z)
mul(&t, &t, &z)
pack(out, &t)
}
func setint(r *[5]uint64, v uint64) {
r[0] = v
r[1] = 0
r[2] = 0
r[3] = 0
r[4] = 0
}
// unpack sets r = x where r consists of 5, 51-bit limbs in little-endian
// order.
func unpack(r *[5]uint64, x *[32]byte) {
r[0] = uint64(x[0]) |
uint64(x[1])<<8 |
uint64(x[2])<<16 |
uint64(x[3])<<24 |
uint64(x[4])<<32 |
uint64(x[5])<<40 |
uint64(x[6]&7)<<48
r[1] = uint64(x[6])>>3 |
uint64(x[7])<<5 |
uint64(x[8])<<13 |
uint64(x[9])<<21 |
uint64(x[10])<<29 |
uint64(x[11])<<37 |
uint64(x[12]&63)<<45
r[2] = uint64(x[12])>>6 |
uint64(x[13])<<2 |
uint64(x[14])<<10 |
uint64(x[15])<<18 |
uint64(x[16])<<26 |
uint64(x[17])<<34 |
uint64(x[18])<<42 |
uint64(x[19]&1)<<50
r[3] = uint64(x[19])>>1 |
uint64(x[20])<<7 |
uint64(x[21])<<15 |
uint64(x[22])<<23 |
uint64(x[23])<<31 |
uint64(x[24])<<39 |
uint64(x[25]&15)<<47
r[4] = uint64(x[25])>>4 |
uint64(x[26])<<4 |
uint64(x[27])<<12 |
uint64(x[28])<<20 |
uint64(x[29])<<28 |
uint64(x[30])<<36 |
uint64(x[31]&127)<<44
}
// pack sets out = x where out is the usual, little-endian form of the 5,
// 51-bit limbs in x.
func pack(out *[32]byte, x *[5]uint64) {
t := *x
freeze(&t)
out[0] = byte(t[0])
out[1] = byte(t[0] >> 8)
out[2] = byte(t[0] >> 16)
out[3] = byte(t[0] >> 24)
out[4] = byte(t[0] >> 32)
out[5] = byte(t[0] >> 40)
out[6] = byte(t[0] >> 48)
out[6] ^= byte(t[1]<<3) & 0xf8
out[7] = byte(t[1] >> 5)
out[8] = byte(t[1] >> 13)
out[9] = byte(t[1] >> 21)
out[10] = byte(t[1] >> 29)
out[11] = byte(t[1] >> 37)
out[12] = byte(t[1] >> 45)
out[12] ^= byte(t[2]<<6) & 0xc0
out[13] = byte(t[2] >> 2)
out[14] = byte(t[2] >> 10)
out[15] = byte(t[2] >> 18)
out[16] = byte(t[2] >> 26)
out[17] = byte(t[2] >> 34)
out[18] = byte(t[2] >> 42)
out[19] = byte(t[2] >> 50)
out[19] ^= byte(t[3]<<1) & 0xfe
out[20] = byte(t[3] >> 7)
out[21] = byte(t[3] >> 15)
out[22] = byte(t[3] >> 23)
out[23] = byte(t[3] >> 31)
out[24] = byte(t[3] >> 39)
out[25] = byte(t[3] >> 47)
out[25] ^= byte(t[4]<<4) & 0xf0
out[26] = byte(t[4] >> 4)
out[27] = byte(t[4] >> 12)
out[28] = byte(t[4] >> 20)
out[29] = byte(t[4] >> 28)
out[30] = byte(t[4] >> 36)
out[31] = byte(t[4] >> 44)
}
// invert calculates r = x^-1 mod p using Fermat's little theorem.
func invert(r *[5]uint64, x *[5]uint64) {
var z2, z9, z11, z2_5_0, z2_10_0, z2_20_0, z2_50_0, z2_100_0, t [5]uint64
square(&z2, x) /* 2 */
square(&t, &z2) /* 4 */
square(&t, &t) /* 8 */
mul(&z9, &t, x) /* 9 */
mul(&z11, &z9, &z2) /* 11 */
square(&t, &z11) /* 22 */
mul(&z2_5_0, &t, &z9) /* 2^5 - 2^0 = 31 */
square(&t, &z2_5_0) /* 2^6 - 2^1 */
for i := 1; i < 5; i++ { /* 2^20 - 2^10 */
square(&t, &t)
}
mul(&z2_10_0, &t, &z2_5_0) /* 2^10 - 2^0 */
square(&t, &z2_10_0) /* 2^11 - 2^1 */
for i := 1; i < 10; i++ { /* 2^20 - 2^10 */
square(&t, &t)
}
mul(&z2_20_0, &t, &z2_10_0) /* 2^20 - 2^0 */
square(&t, &z2_20_0) /* 2^21 - 2^1 */
for i := 1; i < 20; i++ { /* 2^40 - 2^20 */
square(&t, &t)
}
mul(&t, &t, &z2_20_0) /* 2^40 - 2^0 */
square(&t, &t) /* 2^41 - 2^1 */
for i := 1; i < 10; i++ { /* 2^50 - 2^10 */
square(&t, &t)
}
mul(&z2_50_0, &t, &z2_10_0) /* 2^50 - 2^0 */
square(&t, &z2_50_0) /* 2^51 - 2^1 */
for i := 1; i < 50; i++ { /* 2^100 - 2^50 */
square(&t, &t)
}
mul(&z2_100_0, &t, &z2_50_0) /* 2^100 - 2^0 */
square(&t, &z2_100_0) /* 2^101 - 2^1 */
for i := 1; i < 100; i++ { /* 2^200 - 2^100 */
square(&t, &t)
}
mul(&t, &t, &z2_100_0) /* 2^200 - 2^0 */
square(&t, &t) /* 2^201 - 2^1 */
for i := 1; i < 50; i++ { /* 2^250 - 2^50 */
square(&t, &t)
}
mul(&t, &t, &z2_50_0) /* 2^250 - 2^0 */
square(&t, &t) /* 2^251 - 2^1 */
square(&t, &t) /* 2^252 - 2^2 */
square(&t, &t) /* 2^253 - 2^3 */
square(&t, &t) /* 2^254 - 2^4 */
square(&t, &t) /* 2^255 - 2^5 */
mul(r, &t, &z11) /* 2^255 - 21 */
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This code was translated into a form compatible with 6a from the public
// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
// +build amd64,!gccgo,!appengine
// func mul(dest, a, b *[5]uint64)
TEXT ·mul(SB),0,$128-24
MOVQ dest+0(FP), DI
MOVQ a+8(FP), SI
MOVQ b+16(FP), DX
MOVQ SP,R11
MOVQ $31,CX
NOTQ CX
ANDQ CX,SP
ADDQ $32,SP
MOVQ R11,0(SP)
MOVQ R12,8(SP)
MOVQ R13,16(SP)
MOVQ R14,24(SP)
MOVQ R15,32(SP)
MOVQ BX,40(SP)
MOVQ BP,48(SP)
MOVQ DI,56(SP)
MOVQ DX,CX
MOVQ 24(SI),DX
IMUL3Q $19,DX,AX
MOVQ AX,64(SP)
MULQ 16(CX)
MOVQ AX,R8
MOVQ DX,R9
MOVQ 32(SI),DX
IMUL3Q $19,DX,AX
MOVQ AX,72(SP)
MULQ 8(CX)
ADDQ AX,R8
ADCQ DX,R9
MOVQ 0(SI),AX
MULQ 0(CX)
ADDQ AX,R8
ADCQ DX,R9
MOVQ 0(SI),AX
MULQ 8(CX)
MOVQ AX,R10
MOVQ DX,R11
MOVQ 0(SI),AX
MULQ 16(CX)
MOVQ AX,R12
MOVQ DX,R13
MOVQ 0(SI),AX
MULQ 24(CX)
MOVQ AX,R14
MOVQ DX,R15
MOVQ 0(SI),AX
MULQ 32(CX)
MOVQ AX,BX
MOVQ DX,BP
MOVQ 8(SI),AX
MULQ 0(CX)
ADDQ AX,R10
ADCQ DX,R11
MOVQ 8(SI),AX
MULQ 8(CX)
ADDQ AX,R12
ADCQ DX,R13
MOVQ 8(SI),AX
MULQ 16(CX)
ADDQ AX,R14
ADCQ DX,R15
MOVQ 8(SI),AX
MULQ 24(CX)
ADDQ AX,BX
ADCQ DX,BP
MOVQ 8(SI),DX
IMUL3Q $19,DX,AX
MULQ 32(CX)
ADDQ AX,R8
ADCQ DX,R9
MOVQ 16(SI),AX
MULQ 0(CX)
ADDQ AX,R12
ADCQ DX,R13
MOVQ 16(SI),AX
MULQ 8(CX)
ADDQ AX,R14
ADCQ DX,R15
MOVQ 16(SI),AX
MULQ 16(CX)
ADDQ AX,BX
ADCQ DX,BP
MOVQ 16(SI),DX
IMUL3Q $19,DX,AX
MULQ 24(CX)
ADDQ AX,R8
ADCQ DX,R9
MOVQ 16(SI),DX
IMUL3Q $19,DX,AX
MULQ 32(CX)
ADDQ AX,R10
ADCQ DX,R11
MOVQ 24(SI),AX
MULQ 0(CX)
ADDQ AX,R14
ADCQ DX,R15
MOVQ 24(SI),AX
MULQ 8(CX)
ADDQ AX,BX
ADCQ DX,BP
MOVQ 64(SP),AX
MULQ 24(CX)
ADDQ AX,R10
ADCQ DX,R11
MOVQ 64(SP),AX
MULQ 32(CX)
ADDQ AX,R12
ADCQ DX,R13
MOVQ 32(SI),AX
MULQ 0(CX)
ADDQ AX,BX
ADCQ DX,BP
MOVQ 72(SP),AX
MULQ 16(CX)
ADDQ AX,R10
ADCQ DX,R11
MOVQ 72(SP),AX
MULQ 24(CX)
ADDQ AX,R12
ADCQ DX,R13
MOVQ 72(SP),AX
MULQ 32(CX)
ADDQ AX,R14
ADCQ DX,R15
MOVQ ·REDMASK51(SB),SI
SHLQ $13,R9:R8
ANDQ SI,R8
SHLQ $13,R11:R10
ANDQ SI,R10
ADDQ R9,R10
SHLQ $13,R13:R12
ANDQ SI,R12
ADDQ R11,R12
SHLQ $13,R15:R14
ANDQ SI,R14
ADDQ R13,R14
SHLQ $13,BP:BX
ANDQ SI,BX
ADDQ R15,BX
IMUL3Q $19,BP,DX
ADDQ DX,R8
MOVQ R8,DX
SHRQ $51,DX
ADDQ R10,DX
MOVQ DX,CX
SHRQ $51,DX
ANDQ SI,R8
ADDQ R12,DX
MOVQ DX,R9
SHRQ $51,DX
ANDQ SI,CX
ADDQ R14,DX
MOVQ DX,AX
SHRQ $51,DX
ANDQ SI,R9
ADDQ BX,DX
MOVQ DX,R10
SHRQ $51,DX
ANDQ SI,AX
IMUL3Q $19,DX,DX
ADDQ DX,R8
ANDQ SI,R10
MOVQ R8,0(DI)
MOVQ CX,8(DI)
MOVQ R9,16(DI)
MOVQ AX,24(DI)
MOVQ R10,32(DI)
MOVQ 0(SP),R11
MOVQ 8(SP),R12
MOVQ 16(SP),R13
MOVQ 24(SP),R14
MOVQ 32(SP),R15
MOVQ 40(SP),BX
MOVQ 48(SP),BP
MOVQ R11,SP
MOVQ DI,AX
MOVQ SI,DX
RET

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This code was translated into a form compatible with 6a from the public
// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
// +build amd64,!gccgo,!appengine
// func square(out, in *[5]uint64)
TEXT ·square(SB),7,$96-16
MOVQ out+0(FP), DI
MOVQ in+8(FP), SI
MOVQ SP,R11
MOVQ $31,CX
NOTQ CX
ANDQ CX,SP
ADDQ $32, SP
MOVQ R11,0(SP)
MOVQ R12,8(SP)
MOVQ R13,16(SP)
MOVQ R14,24(SP)
MOVQ R15,32(SP)
MOVQ BX,40(SP)
MOVQ BP,48(SP)
MOVQ 0(SI),AX
MULQ 0(SI)
MOVQ AX,CX
MOVQ DX,R8
MOVQ 0(SI),AX
SHLQ $1,AX
MULQ 8(SI)
MOVQ AX,R9
MOVQ DX,R10
MOVQ 0(SI),AX
SHLQ $1,AX
MULQ 16(SI)
MOVQ AX,R11
MOVQ DX,R12
MOVQ 0(SI),AX
SHLQ $1,AX
MULQ 24(SI)
MOVQ AX,R13
MOVQ DX,R14
MOVQ 0(SI),AX
SHLQ $1,AX
MULQ 32(SI)
MOVQ AX,R15
MOVQ DX,BX
MOVQ 8(SI),AX
MULQ 8(SI)
ADDQ AX,R11
ADCQ DX,R12
MOVQ 8(SI),AX
SHLQ $1,AX
MULQ 16(SI)
ADDQ AX,R13
ADCQ DX,R14
MOVQ 8(SI),AX
SHLQ $1,AX
MULQ 24(SI)
ADDQ AX,R15
ADCQ DX,BX
MOVQ 8(SI),DX
IMUL3Q $38,DX,AX
MULQ 32(SI)
ADDQ AX,CX
ADCQ DX,R8
MOVQ 16(SI),AX
MULQ 16(SI)
ADDQ AX,R15
ADCQ DX,BX
MOVQ 16(SI),DX
IMUL3Q $38,DX,AX
MULQ 24(SI)
ADDQ AX,CX
ADCQ DX,R8
MOVQ 16(SI),DX
IMUL3Q $38,DX,AX
MULQ 32(SI)
ADDQ AX,R9
ADCQ DX,R10
MOVQ 24(SI),DX
IMUL3Q $19,DX,AX
MULQ 24(SI)
ADDQ AX,R9
ADCQ DX,R10
MOVQ 24(SI),DX
IMUL3Q $38,DX,AX
MULQ 32(SI)
ADDQ AX,R11
ADCQ DX,R12
MOVQ 32(SI),DX
IMUL3Q $19,DX,AX
MULQ 32(SI)
ADDQ AX,R13
ADCQ DX,R14
MOVQ ·REDMASK51(SB),SI
SHLQ $13,R8:CX
ANDQ SI,CX
SHLQ $13,R10:R9
ANDQ SI,R9
ADDQ R8,R9
SHLQ $13,R12:R11
ANDQ SI,R11
ADDQ R10,R11
SHLQ $13,R14:R13
ANDQ SI,R13
ADDQ R12,R13
SHLQ $13,BX:R15
ANDQ SI,R15
ADDQ R14,R15
IMUL3Q $19,BX,DX
ADDQ DX,CX
MOVQ CX,DX
SHRQ $51,DX
ADDQ R9,DX
ANDQ SI,CX
MOVQ DX,R8
SHRQ $51,DX
ADDQ R11,DX
ANDQ SI,R8
MOVQ DX,R9
SHRQ $51,DX
ADDQ R13,DX
ANDQ SI,R9
MOVQ DX,AX
SHRQ $51,DX
ADDQ R15,DX
ANDQ SI,AX
MOVQ DX,R10
SHRQ $51,DX
IMUL3Q $19,DX,DX
ADDQ DX,CX
ANDQ SI,R10
MOVQ CX,0(DI)
MOVQ R8,8(DI)
MOVQ R9,16(DI)
MOVQ AX,24(DI)
MOVQ R10,32(DI)
MOVQ 0(SP),R11
MOVQ 8(SP),R12
MOVQ 16(SP),R13
MOVQ 24(SP),R14
MOVQ 32(SP),R15
MOVQ 40(SP),BX
MOVQ 48(SP),BP
MOVQ R11,SP
MOVQ DI,AX
MOVQ SI,DX
RET

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vendor/github.com/keybase/go-crypto/ed25519/ed25519.go generated vendored Normal file
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package ed25519 implements the Ed25519 signature algorithm. See
// http://ed25519.cr.yp.to/.
//
// These functions are also compatible with the “Ed25519” function defined in
// https://tools.ietf.org/html/draft-irtf-cfrg-eddsa-05.
package ed25519
// This code is a port of the public domain, “ref10” implementation of ed25519
// from SUPERCOP.
import (
"crypto"
cryptorand "crypto/rand"
"crypto/sha512"
"crypto/subtle"
"errors"
"io"
"strconv"
"github.com/keybase/go-crypto/ed25519/internal/edwards25519"
)
const (
// PublicKeySize is the size, in bytes, of public keys as used in this package.
PublicKeySize = 32
// PrivateKeySize is the size, in bytes, of private keys as used in this package.
PrivateKeySize = 64
// SignatureSize is the size, in bytes, of signatures generated and verified by this package.
SignatureSize = 64
)
// PublicKey is the type of Ed25519 public keys.
type PublicKey []byte
// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
type PrivateKey []byte
// Public returns the PublicKey corresponding to priv.
func (priv PrivateKey) Public() crypto.PublicKey {
publicKey := make([]byte, PublicKeySize)
copy(publicKey, priv[32:])
return PublicKey(publicKey)
}
// Sign signs the given message with priv.
// Ed25519 performs two passes over messages to be signed and therefore cannot
// handle pre-hashed messages. Thus opts.HashFunc() must return zero to
// indicate the message hasn't been hashed. This can be achieved by passing
// crypto.Hash(0) as the value for opts.
func (priv PrivateKey) Sign(rand io.Reader, message []byte, opts crypto.SignerOpts) (signature []byte, err error) {
if opts.HashFunc() != crypto.Hash(0) {
return nil, errors.New("ed25519: cannot sign hashed message")
}
return Sign(priv, message), nil
}
// GenerateKey generates a public/private key pair using entropy from rand.
// If rand is nil, crypto/rand.Reader will be used.
func GenerateKey(rand io.Reader) (publicKey PublicKey, privateKey PrivateKey, err error) {
if rand == nil {
rand = cryptorand.Reader
}
privateKey = make([]byte, PrivateKeySize)
publicKey = make([]byte, PublicKeySize)
_, err = io.ReadFull(rand, privateKey[:32])
if err != nil {
return nil, nil, err
}
digest := sha512.Sum512(privateKey[:32])
digest[0] &= 248
digest[31] &= 127
digest[31] |= 64
var A edwards25519.ExtendedGroupElement
var hBytes [32]byte
copy(hBytes[:], digest[:])
edwards25519.GeScalarMultBase(&A, &hBytes)
var publicKeyBytes [32]byte
A.ToBytes(&publicKeyBytes)
copy(privateKey[32:], publicKeyBytes[:])
copy(publicKey, publicKeyBytes[:])
return publicKey, privateKey, nil
}
// Sign signs the message with privateKey and returns a signature. It will
// panic if len(privateKey) is not PrivateKeySize.
func Sign(privateKey PrivateKey, message []byte) []byte {
if l := len(privateKey); l != PrivateKeySize {
panic("ed25519: bad private key length: " + strconv.Itoa(l))
}
h := sha512.New()
h.Write(privateKey[:32])
var digest1, messageDigest, hramDigest [64]byte
var expandedSecretKey [32]byte
h.Sum(digest1[:0])
copy(expandedSecretKey[:], digest1[:])
expandedSecretKey[0] &= 248
expandedSecretKey[31] &= 63
expandedSecretKey[31] |= 64
h.Reset()
h.Write(digest1[32:])
h.Write(message)
h.Sum(messageDigest[:0])
var messageDigestReduced [32]byte
edwards25519.ScReduce(&messageDigestReduced, &messageDigest)
var R edwards25519.ExtendedGroupElement
edwards25519.GeScalarMultBase(&R, &messageDigestReduced)
var encodedR [32]byte
R.ToBytes(&encodedR)
h.Reset()
h.Write(encodedR[:])
h.Write(privateKey[32:])
h.Write(message)
h.Sum(hramDigest[:0])
var hramDigestReduced [32]byte
edwards25519.ScReduce(&hramDigestReduced, &hramDigest)
var s [32]byte
edwards25519.ScMulAdd(&s, &hramDigestReduced, &expandedSecretKey, &messageDigestReduced)
signature := make([]byte, SignatureSize)
copy(signature[:], encodedR[:])
copy(signature[32:], s[:])
return signature
}
// Verify reports whether sig is a valid signature of message by publicKey. It
// will panic if len(publicKey) is not PublicKeySize.
func Verify(publicKey PublicKey, message, sig []byte) bool {
if l := len(publicKey); l != PublicKeySize {
panic("ed25519: bad public key length: " + strconv.Itoa(l))
}
if len(sig) != SignatureSize || sig[63]&224 != 0 {
return false
}
var A edwards25519.ExtendedGroupElement
var publicKeyBytes [32]byte
copy(publicKeyBytes[:], publicKey)
if !A.FromBytes(&publicKeyBytes) {
return false
}
edwards25519.FeNeg(&A.X, &A.X)
edwards25519.FeNeg(&A.T, &A.T)
h := sha512.New()
h.Write(sig[:32])
h.Write(publicKey[:])
h.Write(message)
var digest [64]byte
h.Sum(digest[:0])
var hReduced [32]byte
edwards25519.ScReduce(&hReduced, &digest)
var R edwards25519.ProjectiveGroupElement
var b [32]byte
copy(b[:], sig[32:])
edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &b)
var checkR [32]byte
R.ToBytes(&checkR)
return subtle.ConstantTimeCompare(sig[:32], checkR[:]) == 1
}

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package armor implements OpenPGP ASCII Armor, see RFC 4880. OpenPGP Armor is
// very similar to PEM except that it has an additional CRC checksum.
package armor // import "github.com/keybase/go-crypto/openpgp/armor"
import (
"bufio"
"bytes"
"encoding/base64"
"io"
"strings"
"unicode"
"github.com/keybase/go-crypto/openpgp/errors"
)
// A Block represents an OpenPGP armored structure.
//
// The encoded form is:
// -----BEGIN Type-----
// Headers
//
// base64-encoded Bytes
// '=' base64 encoded checksum
// -----END Type-----
// where Headers is a possibly empty sequence of Key: Value lines.
//
// Since the armored data can be very large, this package presents a streaming
// interface.
type Block struct {
Type string // The type, taken from the preamble (i.e. "PGP SIGNATURE").
Header map[string]string // Optional headers.
Body io.Reader // A Reader from which the contents can be read
lReader lineReader
oReader openpgpReader
}
var ArmorCorrupt error = errors.StructuralError("armor invalid")
const crc24Init = 0xb704ce
const crc24Poly = 0x1864cfb
const crc24Mask = 0xffffff
// crc24 calculates the OpenPGP checksum as specified in RFC 4880, section 6.1
func crc24(crc uint32, d []byte) uint32 {
for _, b := range d {
crc ^= uint32(b) << 16
for i := 0; i < 8; i++ {
crc <<= 1
if crc&0x1000000 != 0 {
crc ^= crc24Poly
}
}
}
return crc
}
var armorStart = []byte("-----BEGIN ")
var armorEnd = []byte("-----END ")
var armorEndOfLine = []byte("-----")
// lineReader wraps a line based reader. It watches for the end of an armor
// block and records the expected CRC value.
type lineReader struct {
in *bufio.Reader
buf []byte
eof bool
crc *uint32
}
// ourIsSpace checks if a rune is either space according to unicode
// package, or ZeroWidthSpace (which is not a space according to
// unicode module). Used to trim lines during header reading.
func ourIsSpace(r rune) bool {
return r == '\u200b' || unicode.IsSpace(r)
}
func (l *lineReader) Read(p []byte) (n int, err error) {
if l.eof {
return 0, io.EOF
}
if len(l.buf) > 0 {
n = copy(p, l.buf)
l.buf = l.buf[n:]
return
}
line, _, err := l.in.ReadLine()
if err != nil {
return
}
line = bytes.TrimFunc(line, ourIsSpace)
if len(line) == 5 && line[0] == '=' {
// This is the checksum line
var expectedBytes [3]byte
var m int
m, err = base64.StdEncoding.Decode(expectedBytes[0:], line[1:])
if m != 3 || err != nil {
return
}
crc := uint32(expectedBytes[0])<<16 |
uint32(expectedBytes[1])<<8 |
uint32(expectedBytes[2])
l.crc = &crc
for {
line, _, err = l.in.ReadLine()
if err != nil && err != io.EOF {
return
}
if len(strings.TrimSpace(string(line))) > 0 {
break
}
}
if !bytes.HasPrefix(line, armorEnd) {
return 0, ArmorCorrupt
}
l.eof = true
return 0, io.EOF
}
if bytes.HasPrefix(line, armorEnd) {
// Unexpected ending, there was no checksum.
l.eof = true
l.crc = nil
return 0, io.EOF
}
n = copy(p, line)
bytesToSave := len(line) - n
if bytesToSave > 0 {
if cap(l.buf) < bytesToSave {
l.buf = make([]byte, 0, bytesToSave)
}
l.buf = l.buf[0:bytesToSave]
copy(l.buf, line[n:])
}
return
}
// openpgpReader passes Read calls to the underlying base64 decoder, but keeps
// a running CRC of the resulting data and checks the CRC against the value
// found by the lineReader at EOF.
type openpgpReader struct {
lReader *lineReader
b64Reader io.Reader
currentCRC uint32
}
func (r *openpgpReader) Read(p []byte) (n int, err error) {
n, err = r.b64Reader.Read(p)
r.currentCRC = crc24(r.currentCRC, p[:n])
if err == io.EOF {
if r.lReader.crc != nil && *r.lReader.crc != uint32(r.currentCRC&crc24Mask) {
return 0, ArmorCorrupt
}
}
return
}
// Decode reads a PGP armored block from the given Reader. It will ignore
// leading garbage. If it doesn't find a block, it will return nil, io.EOF. The
// given Reader is not usable after calling this function: an arbitrary amount
// of data may have been read past the end of the block.
func Decode(in io.Reader) (p *Block, err error) {
r := bufio.NewReaderSize(in, 100)
var line []byte
ignoreNext := false
TryNextBlock:
p = nil
// Skip leading garbage
for {
ignoreThis := ignoreNext
line, ignoreNext, err = r.ReadLine()
if err != nil {
return
}
if ignoreNext || ignoreThis {
continue
}
line = bytes.TrimSpace(line)
if len(line) > len(armorStart)+len(armorEndOfLine) && bytes.HasPrefix(line, armorStart) {
break
}
}
p = new(Block)
p.Type = string(line[len(armorStart) : len(line)-len(armorEndOfLine)])
p.Header = make(map[string]string)
nextIsContinuation := false
var lastKey string
// Read headers
for {
isContinuation := nextIsContinuation
line, nextIsContinuation, err = r.ReadLine()
if err != nil {
p = nil
return
}
if isContinuation {
p.Header[lastKey] += string(line)
continue
}
line = bytes.TrimFunc(line, ourIsSpace)
if len(line) == 0 {
break
}
i := bytes.Index(line, []byte(": "))
if i == -1 {
goto TryNextBlock
}
lastKey = string(line[:i])
p.Header[lastKey] = string(line[i+2:])
}
p.lReader.in = r
p.oReader.currentCRC = crc24Init
p.oReader.lReader = &p.lReader
p.oReader.b64Reader = base64.NewDecoder(base64.StdEncoding, &p.lReader)
p.Body = &p.oReader
return
}

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package armor
import (
"encoding/base64"
"io"
)
var armorHeaderSep = []byte(": ")
var blockEnd = []byte("\n=")
var newline = []byte("\n")
var armorEndOfLineOut = []byte("-----\n")
// writeSlices writes its arguments to the given Writer.
func writeSlices(out io.Writer, slices ...[]byte) (err error) {
for _, s := range slices {
_, err = out.Write(s)
if err != nil {
return err
}
}
return
}
// lineBreaker breaks data across several lines, all of the same byte length
// (except possibly the last). Lines are broken with a single '\n'.
type lineBreaker struct {
lineLength int
line []byte
used int
out io.Writer
haveWritten bool
}
func newLineBreaker(out io.Writer, lineLength int) *lineBreaker {
return &lineBreaker{
lineLength: lineLength,
line: make([]byte, lineLength),
used: 0,
out: out,
}
}
func (l *lineBreaker) Write(b []byte) (n int, err error) {
n = len(b)
if n == 0 {
return
}
if l.used == 0 && l.haveWritten {
_, err = l.out.Write([]byte{'\n'})
if err != nil {
return
}
}
if l.used+len(b) < l.lineLength {
l.used += copy(l.line[l.used:], b)
return
}
l.haveWritten = true
_, err = l.out.Write(l.line[0:l.used])
if err != nil {
return
}
excess := l.lineLength - l.used
l.used = 0
_, err = l.out.Write(b[0:excess])
if err != nil {
return
}
_, err = l.Write(b[excess:])
return
}
func (l *lineBreaker) Close() (err error) {
if l.used > 0 {
_, err = l.out.Write(l.line[0:l.used])
if err != nil {
return
}
}
return
}
// encoding keeps track of a running CRC24 over the data which has been written
// to it and outputs a OpenPGP checksum when closed, followed by an armor
// trailer.
//
// It's built into a stack of io.Writers:
// encoding -> base64 encoder -> lineBreaker -> out
type encoding struct {
out io.Writer
breaker *lineBreaker
b64 io.WriteCloser
crc uint32
blockType []byte
}
func (e *encoding) Write(data []byte) (n int, err error) {
e.crc = crc24(e.crc, data)
return e.b64.Write(data)
}
func (e *encoding) Close() (err error) {
err = e.b64.Close()
if err != nil {
return
}
e.breaker.Close()
var checksumBytes [3]byte
checksumBytes[0] = byte(e.crc >> 16)
checksumBytes[1] = byte(e.crc >> 8)
checksumBytes[2] = byte(e.crc)
var b64ChecksumBytes [4]byte
base64.StdEncoding.Encode(b64ChecksumBytes[:], checksumBytes[:])
return writeSlices(e.out, blockEnd, b64ChecksumBytes[:], newline, armorEnd, e.blockType, armorEndOfLine, []byte{'\n'})
}
// Encode returns a WriteCloser which will encode the data written to it in
// OpenPGP armor.
func Encode(out io.Writer, blockType string, headers map[string]string) (w io.WriteCloser, err error) {
bType := []byte(blockType)
err = writeSlices(out, armorStart, bType, armorEndOfLineOut)
if err != nil {
return
}
for k, v := range headers {
err = writeSlices(out, []byte(k), armorHeaderSep, []byte(v), newline)
if err != nil {
return
}
}
_, err = out.Write(newline)
if err != nil {
return
}
e := &encoding{
out: out,
breaker: newLineBreaker(out, 64),
crc: crc24Init,
blockType: bType,
}
e.b64 = base64.NewEncoder(base64.StdEncoding, e.breaker)
return e, nil
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package openpgp
import "hash"
// NewCanonicalTextHash reformats text written to it into the canonical
// form and then applies the hash h. See RFC 4880, section 5.2.1.
func NewCanonicalTextHash(h hash.Hash) hash.Hash {
return &canonicalTextHash{h, 0}
}
type canonicalTextHash struct {
h hash.Hash
s int
}
var newline = []byte{'\r', '\n'}
func (cth *canonicalTextHash) Write(buf []byte) (int, error) {
start := 0
for i, c := range buf {
switch cth.s {
case 0:
if c == '\r' {
cth.s = 1
} else if c == '\n' {
cth.h.Write(buf[start:i])
cth.h.Write(newline)
start = i + 1
}
case 1:
cth.s = 0
}
}
cth.h.Write(buf[start:])
return len(buf), nil
}
func (cth *canonicalTextHash) Sum(in []byte) []byte {
return cth.h.Sum(in)
}
func (cth *canonicalTextHash) Reset() {
cth.h.Reset()
cth.s = 0
}
func (cth *canonicalTextHash) Size() int {
return cth.h.Size()
}
func (cth *canonicalTextHash) BlockSize() int {
return cth.h.BlockSize()
}

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package ecdh
import (
"bytes"
"crypto"
"crypto/aes"
"crypto/elliptic"
"encoding/binary"
"errors"
"github.com/keybase/go-crypto/curve25519"
"io"
"math/big"
)
type PublicKey struct {
elliptic.Curve
X, Y *big.Int
}
type PrivateKey struct {
PublicKey
X *big.Int
}
// KDF implements Key Derivation Function as described in
// https://tools.ietf.org/html/rfc6637#section-7
func (e *PublicKey) KDF(S []byte, kdfParams []byte, hash crypto.Hash) []byte {
sLen := (e.Curve.Params().P.BitLen() + 7) / 8
buf := new(bytes.Buffer)
buf.Write([]byte{0, 0, 0, 1})
if sLen > len(S) {
// zero-pad the S. If we got invalid S (bigger than curve's
// P), we are going to produce invalid key. Garbage in,
// garbage out.
buf.Write(make([]byte, sLen-len(S)))
}
buf.Write(S)
buf.Write(kdfParams)
hashw := hash.New()
hashw.Write(buf.Bytes())
key := hashw.Sum(nil)
return key
}
// AESKeyUnwrap implements RFC 3394 Key Unwrapping. See
// http://tools.ietf.org/html/rfc3394#section-2.2.1
// Note: The second described algorithm ("index-based") is implemented
// here.
func AESKeyUnwrap(key, cipherText []byte) ([]byte, error) {
if len(cipherText)%8 != 0 {
return nil, errors.New("cipherText must by a multiple of 64 bits")
}
cipher, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
nblocks := len(cipherText)/8 - 1
// 1) Initialize variables.
// - Set A = C[0]
var A [aes.BlockSize]byte
copy(A[:8], cipherText[:8])
// For i = 1 to n
// Set R[i] = C[i]
R := make([]byte, len(cipherText)-8)
copy(R, cipherText[8:])
// 2) Compute intermediate values.
for j := 5; j >= 0; j-- {
for i := nblocks - 1; i >= 0; i-- {
// B = AES-1(K, (A ^ t) | R[i]) where t = n*j+i
// A = MSB(64, B)
t := uint64(nblocks*j + i + 1)
At := binary.BigEndian.Uint64(A[:8]) ^ t
binary.BigEndian.PutUint64(A[:8], At)
copy(A[8:], R[i*8:i*8+8])
cipher.Decrypt(A[:], A[:])
// R[i] = LSB(B, 64)
copy(R[i*8:i*8+8], A[8:])
}
}
// 3) Output results.
// If A is an appropriate initial value (see 2.2.3),
for i := 0; i < 8; i++ {
if A[i] != 0xA6 {
return nil, errors.New("Failed to unwrap key (A is not IV)")
}
}
return R, nil
}
// AESKeyWrap implements RFC 3394 Key Wrapping. See
// https://tools.ietf.org/html/rfc3394#section-2.2.2
// Note: The second described algorithm ("index-based") is implemented
// here.
func AESKeyWrap(key, plainText []byte) ([]byte, error) {
if len(plainText)%8 != 0 {
return nil, errors.New("plainText must be a multiple of 64 bits")
}
cipher, err := aes.NewCipher(key) // NewCipher checks key size
if err != nil {
return nil, err
}
nblocks := len(plainText) / 8
// 1) Initialize variables.
var A [aes.BlockSize]byte
// Section 2.2.3.1 -- Initial Value
// http://tools.ietf.org/html/rfc3394#section-2.2.3.1
for i := 0; i < 8; i++ {
A[i] = 0xA6
}
// For i = 1 to n
// Set R[i] = P[i]
R := make([]byte, len(plainText))
copy(R, plainText)
// 2) Calculate intermediate values.
for j := 0; j <= 5; j++ {
for i := 0; i < nblocks; i++ {
// B = AES(K, A | R[i])
copy(A[8:], R[i*8:i*8+8])
cipher.Encrypt(A[:], A[:])
// (Assume B = A)
// A = MSB(64, B) ^ t where t = (n*j)+1
t := uint64(j*nblocks + i + 1)
At := binary.BigEndian.Uint64(A[:8]) ^ t
binary.BigEndian.PutUint64(A[:8], At)
// R[i] = LSB(64, B)
copy(R[i*8:i*8+8], A[8:])
}
}
// 3) Output results.
// Set C[0] = A
// For i = 1 to n
// C[i] = R[i]
return append(A[:8], R...), nil
}
// PadBuffer pads byte buffer buf to a length being multiple of
// blockLen. Additional bytes appended to the buffer have value of the
// number padded bytes. E.g. if the buffer is 3 bytes short of being
// 40 bytes total, the appended bytes will be [03, 03, 03].
func PadBuffer(buf []byte, blockLen int) []byte {
padding := blockLen - (len(buf) % blockLen)
if padding == 0 {
return buf
}
padBuf := make([]byte, padding)
for i := 0; i < padding; i++ {
padBuf[i] = byte(padding)
}
return append(buf, padBuf...)
}
// UnpadBuffer verifies that buffer contains proper padding and
// returns buffer without the padding, or nil if the padding was
// invalid.
func UnpadBuffer(buf []byte, dataLen int) []byte {
padding := len(buf) - dataLen
outBuf := buf[:dataLen]
for i := dataLen; i < len(buf); i++ {
if buf[i] != byte(padding) {
// Invalid padding - bail out
return nil
}
}
return outBuf
}
func (e *PublicKey) Encrypt(random io.Reader, kdfParams []byte, plain []byte, hash crypto.Hash, kdfKeySize int) (Vx *big.Int, Vy *big.Int, C []byte, err error) {
// Vx, Vy - encryption key
// Note for Curve 25519 - curve25519 library already does key
// clamping in scalarMult, so we can use generic random scalar
// generation from elliptic.
priv, Vx, Vy, err := elliptic.GenerateKey(e.Curve, random)
if err != nil {
return nil, nil, nil, err
}
// Sx, Sy - shared secret
Sx, _ := e.Curve.ScalarMult(e.X, e.Y, priv)
// Encrypt the payload with KDF-ed S as the encryption key. Pass
// the ciphertext along with V to the recipient. Recipient can
// generate S using V and their priv key, and then KDF(S), on
// their own, to get encryption key and decrypt the ciphertext,
// revealing encryption key for symmetric encryption later.
plain = PadBuffer(plain, 8)
key := e.KDF(Sx.Bytes(), kdfParams, hash)
// Take only as many bytes from key as the key length (the hash
// result might be bigger)
encrypted, err := AESKeyWrap(key[:kdfKeySize], plain)
return Vx, Vy, encrypted, nil
}
func (e *PrivateKey) DecryptShared(X, Y *big.Int) []byte {
Sx, _ := e.Curve.ScalarMult(X, Y, e.X.Bytes())
return Sx.Bytes()
}
func countBits(buffer []byte) int {
var headerLen int
switch buffer[0] {
case 0x4:
headerLen = 3
case 0x40:
headerLen = 7
default:
// Unexpected header - but we can still count the bits.
val := buffer[0]
headerLen = 0
for val > 0 {
val = val / 2
headerLen++
}
}
return headerLen + (len(buffer)-1)*8
}
// elliptic.Marshal and elliptic.Unmarshal only marshals uncompressed
// 0x4 MPI types. These functions will check if the curve is cv25519,
// and if so, use 0x40 compressed type to (un)marshal. Otherwise,
// elliptic.(Un)marshal will be called.
// Marshal encodes point into either 0x4 uncompressed point form, or
// 0x40 compressed point for Curve 25519.
func Marshal(curve elliptic.Curve, x, y *big.Int) (buf []byte, bitSize int) {
// NOTE: Read more about MPI encoding in the RFC:
// https://tools.ietf.org/html/rfc4880#section-3.2
// We are required to encode size in bits, counting from the most-
// significant non-zero bit. So assuming that the buffer never
// starts with 0x00, we only need to count bits in the first byte
// - and in current implentation it will always be 0x4 or 0x40.
cv, ok := curve25519.ToCurve25519(curve)
if ok {
buf = cv.MarshalType40(x, y)
} else {
buf = elliptic.Marshal(curve, x, y)
}
return buf, countBits(buf)
}
// Unmarshal converts point, serialized by Marshal, into x, y pair.
// For 0x40 compressed points (for Curve 25519), y will always be 0.
// It is an error if point is not on the curve, On error, x = nil.
func Unmarshal(curve elliptic.Curve, data []byte) (x, y *big.Int) {
cv, ok := curve25519.ToCurve25519(curve)
if ok {
return cv.UnmarshalType40(data)
}
return elliptic.Unmarshal(curve, data)
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package elgamal implements ElGamal encryption, suitable for OpenPGP,
// as specified in "A Public-Key Cryptosystem and a Signature Scheme Based on
// Discrete Logarithms," IEEE Transactions on Information Theory, v. IT-31,
// n. 4, 1985, pp. 469-472.
//
// This form of ElGamal embeds PKCS#1 v1.5 padding, which may make it
// unsuitable for other protocols. RSA should be used in preference in any
// case.
package elgamal // import "github.com/keybase/go-crypto/openpgp/elgamal"
import (
"crypto/rand"
"crypto/subtle"
"errors"
"io"
"math/big"
)
// PublicKey represents an ElGamal public key.
type PublicKey struct {
G, P, Y *big.Int
}
// PrivateKey represents an ElGamal private key.
type PrivateKey struct {
PublicKey
X *big.Int
}
// Encrypt encrypts the given message to the given public key. The result is a
// pair of integers. Errors can result from reading random, or because msg is
// too large to be encrypted to the public key.
func Encrypt(random io.Reader, pub *PublicKey, msg []byte) (c1, c2 *big.Int, err error) {
pLen := (pub.P.BitLen() + 7) / 8
if len(msg) > pLen-11 {
err = errors.New("elgamal: message too long")
return
}
// EM = 0x02 || PS || 0x00 || M
em := make([]byte, pLen-1)
em[0] = 2
ps, mm := em[1:len(em)-len(msg)-1], em[len(em)-len(msg):]
err = nonZeroRandomBytes(ps, random)
if err != nil {
return
}
em[len(em)-len(msg)-1] = 0
copy(mm, msg)
m := new(big.Int).SetBytes(em)
k, err := rand.Int(random, pub.P)
if err != nil {
return
}
c1 = new(big.Int).Exp(pub.G, k, pub.P)
s := new(big.Int).Exp(pub.Y, k, pub.P)
c2 = s.Mul(s, m)
c2.Mod(c2, pub.P)
return
}
// Decrypt takes two integers, resulting from an ElGamal encryption, and
// returns the plaintext of the message. An error can result only if the
// ciphertext is invalid. Users should keep in mind that this is a padding
// oracle and thus, if exposed to an adaptive chosen ciphertext attack, can
// be used to break the cryptosystem. See ``Chosen Ciphertext Attacks
// Against Protocols Based on the RSA Encryption Standard PKCS #1'', Daniel
// Bleichenbacher, Advances in Cryptology (Crypto '98),
func Decrypt(priv *PrivateKey, c1, c2 *big.Int) (msg []byte, err error) {
s := new(big.Int).Exp(c1, priv.X, priv.P)
s.ModInverse(s, priv.P)
s.Mul(s, c2)
s.Mod(s, priv.P)
em := s.Bytes()
firstByteIsTwo := subtle.ConstantTimeByteEq(em[0], 2)
// The remainder of the plaintext must be a string of non-zero random
// octets, followed by a 0, followed by the message.
// lookingForIndex: 1 iff we are still looking for the zero.
// index: the offset of the first zero byte.
var lookingForIndex, index int
lookingForIndex = 1
for i := 1; i < len(em); i++ {
equals0 := subtle.ConstantTimeByteEq(em[i], 0)
index = subtle.ConstantTimeSelect(lookingForIndex&equals0, i, index)
lookingForIndex = subtle.ConstantTimeSelect(equals0, 0, lookingForIndex)
}
if firstByteIsTwo != 1 || lookingForIndex != 0 || index < 9 {
return nil, errors.New("elgamal: decryption error")
}
return em[index+1:], nil
}
// nonZeroRandomBytes fills the given slice with non-zero random octets.
func nonZeroRandomBytes(s []byte, rand io.Reader) (err error) {
_, err = io.ReadFull(rand, s)
if err != nil {
return
}
for i := 0; i < len(s); i++ {
for s[i] == 0 {
_, err = io.ReadFull(rand, s[i:i+1])
if err != nil {
return
}
}
}
return
}

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package errors contains common error types for the OpenPGP packages.
package errors // import "github.com/keybase/go-crypto/openpgp/errors"
import (
"strconv"
)
// A StructuralError is returned when OpenPGP data is found to be syntactically
// invalid.
type StructuralError string
func (s StructuralError) Error() string {
return "openpgp: invalid data: " + string(s)
}
// UnsupportedError indicates that, although the OpenPGP data is valid, it
// makes use of currently unimplemented features.
type UnsupportedError string
func (s UnsupportedError) Error() string {
return "openpgp: unsupported feature: " + string(s)
}
// InvalidArgumentError indicates that the caller is in error and passed an
// incorrect value.
type InvalidArgumentError string
func (i InvalidArgumentError) Error() string {
return "openpgp: invalid argument: " + string(i)
}
// SignatureError indicates that a syntactically valid signature failed to
// validate.
type SignatureError string
func (b SignatureError) Error() string {
return "openpgp: invalid signature: " + string(b)
}
type keyIncorrectError int
func (ki keyIncorrectError) Error() string {
return "openpgp: incorrect key"
}
var ErrKeyIncorrect error = keyIncorrectError(0)
type unknownIssuerError int
func (unknownIssuerError) Error() string {
return "openpgp: signature made by unknown entity"
}
var ErrUnknownIssuer error = unknownIssuerError(0)
type keyRevokedError int
func (keyRevokedError) Error() string {
return "openpgp: signature made by revoked key"
}
var ErrKeyRevoked error = keyRevokedError(0)
type UnknownPacketTypeError uint8
func (upte UnknownPacketTypeError) Error() string {
return "openpgp: unknown packet type: " + strconv.Itoa(int(upte))
}

902
vendor/github.com/keybase/go-crypto/openpgp/keys.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package openpgp
import (
"crypto/hmac"
"encoding/binary"
"io"
"time"
"github.com/keybase/go-crypto/openpgp/armor"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/packet"
"github.com/keybase/go-crypto/rsa"
)
// PublicKeyType is the armor type for a PGP public key.
var PublicKeyType = "PGP PUBLIC KEY BLOCK"
// PrivateKeyType is the armor type for a PGP private key.
var PrivateKeyType = "PGP PRIVATE KEY BLOCK"
// An Entity represents the components of an OpenPGP key: a primary public key
// (which must be a signing key), one or more identities claimed by that key,
// and zero or more subkeys, which may be encryption keys.
type Entity struct {
PrimaryKey *packet.PublicKey
PrivateKey *packet.PrivateKey
Identities map[string]*Identity // indexed by Identity.Name
Revocations []*packet.Signature
// Revocations that are signed by designated revokers. Reading keys
// will not verify these revocations, because it won't have access to
// issuers' public keys, API consumers should do this instead (or
// not, and just assume that the key is probably revoked).
UnverifiedRevocations []*packet.Signature
Subkeys []Subkey
BadSubkeys []BadSubkey
}
// An Identity represents an identity claimed by an Entity and zero or more
// assertions by other entities about that claim.
type Identity struct {
Name string // by convention, has the form "Full Name (comment) <email@example.com>"
UserId *packet.UserId
SelfSignature *packet.Signature
Signatures []*packet.Signature
Revocation *packet.Signature
}
// A Subkey is an additional public key in an Entity. Subkeys can be used for
// encryption.
type Subkey struct {
PublicKey *packet.PublicKey
PrivateKey *packet.PrivateKey
Sig *packet.Signature
Revocation *packet.Signature
}
// BadSubkey is one that failed reconstruction, but we'll keep it around for
// informational purposes.
type BadSubkey struct {
Subkey
Err error
}
// A Key identifies a specific public key in an Entity. This is either the
// Entity's primary key or a subkey.
type Key struct {
Entity *Entity
PublicKey *packet.PublicKey
PrivateKey *packet.PrivateKey
SelfSignature *packet.Signature
KeyFlags packet.KeyFlagBits
}
// A KeyRing provides access to public and private keys.
type KeyRing interface {
// KeysById returns the set of keys that have the given key id.
// fp can be optionally supplied, which is the full key fingerprint.
// If it's provided, then it must match. This comes up in the case
// of GPG subpacket 33.
KeysById(id uint64, fp []byte) []Key
// KeysByIdAndUsage returns the set of keys with the given id
// that also meet the key usage given by requiredUsage.
// The requiredUsage is expressed as the bitwise-OR of
// packet.KeyFlag* values.
// fp can be optionally supplied, which is the full key fingerprint.
// If it's provided, then it must match. This comes up in the case
// of GPG subpacket 33.
KeysByIdUsage(id uint64, fp []byte, requiredUsage byte) []Key
// DecryptionKeys returns all private keys that are valid for
// decryption.
DecryptionKeys() []Key
}
// primaryIdentity returns the Identity marked as primary or the first identity
// if none are so marked.
func (e *Entity) primaryIdentity() *Identity {
var firstIdentity *Identity
for _, ident := range e.Identities {
if firstIdentity == nil {
firstIdentity = ident
}
if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId {
return ident
}
}
return firstIdentity
}
// encryptionKey returns the best candidate Key for encrypting a message to the
// given Entity.
func (e *Entity) encryptionKey(now time.Time) (Key, bool) {
candidateSubkey := -1
// Iterate the keys to find the newest key
var maxTime time.Time
for i, subkey := range e.Subkeys {
// NOTE(maxtaco)
// If there is a Flags subpacket, then we have to follow it, and only
// use keys that are marked for Encryption of Communication. If there
// isn't a Flags subpacket, and this is an Encrypt-Only key (right now only ElGamal
// suffices), then we implicitly use it. The check for primary below is a little
// more open-ended, but for now, let's be strict and potentially open up
// if we see bugs in the wild.
//
// One more note: old DSA/ElGamal keys tend not to have the Flags subpacket,
// so this sort of thing is pretty important for encrypting to older keys.
//
if ((subkey.Sig.FlagsValid && subkey.Sig.FlagEncryptCommunications) ||
(!subkey.Sig.FlagsValid && subkey.PublicKey.PubKeyAlgo == packet.PubKeyAlgoElGamal)) &&
subkey.PublicKey.PubKeyAlgo.CanEncrypt() &&
!subkey.Sig.KeyExpired(now) &&
subkey.Revocation == nil &&
(maxTime.IsZero() || subkey.Sig.CreationTime.After(maxTime)) {
candidateSubkey = i
maxTime = subkey.Sig.CreationTime
}
}
if candidateSubkey != -1 {
subkey := e.Subkeys[candidateSubkey]
return Key{e, subkey.PublicKey, subkey.PrivateKey, subkey.Sig, subkey.Sig.GetKeyFlags()}, true
}
// If we don't have any candidate subkeys for encryption and
// the primary key doesn't have any usage metadata then we
// assume that the primary key is ok. Or, if the primary key is
// marked as ok to encrypt to, then we can obviously use it.
//
// NOTE(maxtaco) - see note above, how this policy is a little too open-ended
// for my liking, but leave it for now.
i := e.primaryIdentity()
if (!i.SelfSignature.FlagsValid || i.SelfSignature.FlagEncryptCommunications) &&
e.PrimaryKey.PubKeyAlgo.CanEncrypt() &&
!i.SelfSignature.KeyExpired(now) {
return Key{e, e.PrimaryKey, e.PrivateKey, i.SelfSignature, i.SelfSignature.GetKeyFlags()}, true
}
// This Entity appears to be signing only.
return Key{}, false
}
// signingKey return the best candidate Key for signing a message with this
// Entity.
func (e *Entity) signingKey(now time.Time) (Key, bool) {
candidateSubkey := -1
for i, subkey := range e.Subkeys {
if (!subkey.Sig.FlagsValid || subkey.Sig.FlagSign) &&
subkey.PrivateKey.PrivateKey != nil &&
subkey.PublicKey.PubKeyAlgo.CanSign() &&
subkey.Revocation == nil &&
!subkey.Sig.KeyExpired(now) {
candidateSubkey = i
break
}
}
if candidateSubkey != -1 {
subkey := e.Subkeys[candidateSubkey]
return Key{e, subkey.PublicKey, subkey.PrivateKey, subkey.Sig, subkey.Sig.GetKeyFlags()}, true
}
// If we have no candidate subkey then we assume that it's ok to sign
// with the primary key.
i := e.primaryIdentity()
if (!i.SelfSignature.FlagsValid || i.SelfSignature.FlagSign) &&
e.PrimaryKey.PubKeyAlgo.CanSign() &&
!i.SelfSignature.KeyExpired(now) &&
e.PrivateKey.PrivateKey != nil {
return Key{e, e.PrimaryKey, e.PrivateKey, i.SelfSignature, i.SelfSignature.GetKeyFlags()}, true
}
return Key{}, false
}
// An EntityList contains one or more Entities.
type EntityList []*Entity
func keyMatchesIdAndFingerprint(key *packet.PublicKey, id uint64, fp []byte) bool {
if key.KeyId != id {
return false
}
if fp == nil {
return true
}
return hmac.Equal(fp, key.Fingerprint[:])
}
// KeysById returns the set of keys that have the given key id.
// fp can be optionally supplied, which is the full key fingerprint.
// If it's provided, then it must match. This comes up in the case
// of GPG subpacket 33.
func (el EntityList) KeysById(id uint64, fp []byte) (keys []Key) {
for _, e := range el {
if keyMatchesIdAndFingerprint(e.PrimaryKey, id, fp) {
var selfSig *packet.Signature
for _, ident := range e.Identities {
if selfSig == nil {
selfSig = ident.SelfSignature
} else if ident.SelfSignature.IsPrimaryId != nil && *ident.SelfSignature.IsPrimaryId {
selfSig = ident.SelfSignature
break
}
}
var keyFlags packet.KeyFlagBits
for _, ident := range e.Identities {
keyFlags.Merge(ident.SelfSignature.GetKeyFlags())
}
keys = append(keys, Key{e, e.PrimaryKey, e.PrivateKey, selfSig, keyFlags})
}
for _, subKey := range e.Subkeys {
if keyMatchesIdAndFingerprint(subKey.PublicKey, id, fp) {
// If there's both a a revocation and a sig, then take the
// revocation. Otherwise, we can proceed with the sig.
sig := subKey.Revocation
if sig == nil {
sig = subKey.Sig
}
keys = append(keys, Key{e, subKey.PublicKey, subKey.PrivateKey, sig, sig.GetKeyFlags()})
}
}
}
return
}
// KeysByIdAndUsage returns the set of keys with the given id that also meet
// the key usage given by requiredUsage. The requiredUsage is expressed as
// the bitwise-OR of packet.KeyFlag* values.
// fp can be optionally supplied, which is the full key fingerprint.
// If it's provided, then it must match. This comes up in the case
// of GPG subpacket 33.
func (el EntityList) KeysByIdUsage(id uint64, fp []byte, requiredUsage byte) (keys []Key) {
for _, key := range el.KeysById(id, fp) {
if len(key.Entity.Revocations) > 0 {
continue
}
if key.SelfSignature.RevocationReason != nil {
continue
}
if requiredUsage != 0 {
var usage byte
switch {
case key.KeyFlags.Valid:
usage = key.KeyFlags.BitField
case key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoElGamal:
// We also need to handle the case where, although the sig's
// flags aren't valid, the key can is implicitly usable for
// encryption by virtue of being ElGamal. See also the comment
// in encryptionKey() above.
usage |= packet.KeyFlagEncryptCommunications
usage |= packet.KeyFlagEncryptStorage
case key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoDSA ||
key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoECDSA ||
key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoEdDSA:
usage |= packet.KeyFlagSign
// For a primary RSA key without any key flags, be as permissiable
// as possible.
case key.PublicKey.PubKeyAlgo == packet.PubKeyAlgoRSA &&
keyMatchesIdAndFingerprint(key.Entity.PrimaryKey, id, fp):
usage = (packet.KeyFlagCertify | packet.KeyFlagSign |
packet.KeyFlagEncryptCommunications | packet.KeyFlagEncryptStorage)
}
if usage&requiredUsage != requiredUsage {
continue
}
}
keys = append(keys, key)
}
return
}
// DecryptionKeys returns all private keys that are valid for decryption.
func (el EntityList) DecryptionKeys() (keys []Key) {
for _, e := range el {
for _, subKey := range e.Subkeys {
if subKey.PrivateKey != nil && subKey.PrivateKey.PrivateKey != nil && (!subKey.Sig.FlagsValid || subKey.Sig.FlagEncryptStorage || subKey.Sig.FlagEncryptCommunications) {
keys = append(keys, Key{e, subKey.PublicKey, subKey.PrivateKey, subKey.Sig, subKey.Sig.GetKeyFlags()})
}
}
}
return
}
// ReadArmoredKeyRing reads one or more public/private keys from an armor keyring file.
func ReadArmoredKeyRing(r io.Reader) (EntityList, error) {
block, err := armor.Decode(r)
if err == io.EOF {
return nil, errors.InvalidArgumentError("no armored data found")
}
if err != nil {
return nil, err
}
if block.Type != PublicKeyType && block.Type != PrivateKeyType {
return nil, errors.InvalidArgumentError("expected public or private key block, got: " + block.Type)
}
return ReadKeyRing(block.Body)
}
// ReadKeyRing reads one or more public/private keys. Unsupported keys are
// ignored as long as at least a single valid key is found.
func ReadKeyRing(r io.Reader) (el EntityList, err error) {
packets := packet.NewReader(r)
var lastUnsupportedError error
for {
var e *Entity
e, err = ReadEntity(packets)
if err != nil {
// TODO: warn about skipped unsupported/unreadable keys
if _, ok := err.(errors.UnsupportedError); ok {
lastUnsupportedError = err
err = readToNextPublicKey(packets)
} else if _, ok := err.(errors.StructuralError); ok {
// Skip unreadable, badly-formatted keys
lastUnsupportedError = err
err = readToNextPublicKey(packets)
}
if err == io.EOF {
err = nil
break
}
if err != nil {
el = nil
break
}
} else {
el = append(el, e)
}
}
if len(el) == 0 && err == nil {
err = lastUnsupportedError
}
return
}
// readToNextPublicKey reads packets until the start of the entity and leaves
// the first packet of the new entity in the Reader.
func readToNextPublicKey(packets *packet.Reader) (err error) {
var p packet.Packet
for {
p, err = packets.Next()
if err == io.EOF {
return
} else if err != nil {
if _, ok := err.(errors.UnsupportedError); ok {
err = nil
continue
}
return
}
if pk, ok := p.(*packet.PublicKey); ok && !pk.IsSubkey {
packets.Unread(p)
return
}
}
panic("unreachable")
}
// ReadEntity reads an entity (public key, identities, subkeys etc) from the
// given Reader.
func ReadEntity(packets *packet.Reader) (*Entity, error) {
e := new(Entity)
e.Identities = make(map[string]*Identity)
p, err := packets.Next()
if err != nil {
return nil, err
}
var ok bool
if e.PrimaryKey, ok = p.(*packet.PublicKey); !ok {
if e.PrivateKey, ok = p.(*packet.PrivateKey); !ok {
packets.Unread(p)
return nil, errors.StructuralError("first packet was not a public/private key")
} else {
e.PrimaryKey = &e.PrivateKey.PublicKey
}
}
if !e.PrimaryKey.PubKeyAlgo.CanSign() {
return nil, errors.StructuralError("primary key cannot be used for signatures")
}
var current *Identity
var revocations []*packet.Signature
designatedRevokers := make(map[uint64]bool)
EachPacket:
for {
p, err := packets.Next()
if err == io.EOF {
break
} else if err != nil {
return nil, err
}
switch pkt := p.(type) {
case *packet.UserId:
// Make a new Identity object, that we might wind up throwing away.
// We'll only add it if we get a valid self-signature over this
// userID.
current = new(Identity)
current.Name = pkt.Id
current.UserId = pkt
case *packet.Signature:
if pkt.SigType == packet.SigTypeKeyRevocation {
// These revocations won't revoke UIDs (see
// SigTypeIdentityRevocation). Handle these first,
// because key might have revocation coming from
// another key (designated revoke).
revocations = append(revocations, pkt)
continue
}
// These are signatures by other people on this key. Let's just ignore them
// from the beginning, since they shouldn't affect our key decoding one way
// or the other.
if pkt.IssuerKeyId != nil && *pkt.IssuerKeyId != e.PrimaryKey.KeyId {
continue
}
// If this is a signature made by the keyholder, and the signature has stubbed out
// critical packets, then *now* we need to bail out.
if e := pkt.StubbedOutCriticalError; e != nil {
return nil, e
}
// Next handle the case of a self-signature. According to RFC8440,
// Section 5.2.3.3, if there are several self-signatures,
// we should take the newer one. If they were both created
// at the same time, but one of them has keyflags specified and the
// other doesn't, keep the one with the keyflags. We have actually
// seen this in the wild (see the 'Yield' test in read_test.go).
// If there is a tie, and both have the same value for FlagsValid,
// then "last writer wins."
//
// HOWEVER! We have seen yet more keys in the wild (see the 'Spiros'
// test in read_test.go), in which the later self-signature is a bunch
// of junk, and doesn't even specify key flags. Does it really make
// sense to overwrite reasonable key flags with the empty set? I'm not
// sure what that would be trying to achieve, and plus GPG seems to be
// ok with this situation, and ignores the later (empty) keyflag set.
// So further tighten our overwrite rules, and only allow the later
// signature to overwrite the earlier signature if so doing won't
// trash the key flags.
if current != nil &&
(current.SelfSignature == nil ||
(!pkt.CreationTime.Before(current.SelfSignature.CreationTime) &&
(pkt.FlagsValid || !current.SelfSignature.FlagsValid))) &&
(pkt.SigType == packet.SigTypePositiveCert || pkt.SigType == packet.SigTypeGenericCert) &&
pkt.IssuerKeyId != nil &&
*pkt.IssuerKeyId == e.PrimaryKey.KeyId {
if err = e.PrimaryKey.VerifyUserIdSignature(current.Name, e.PrimaryKey, pkt); err == nil {
current.SelfSignature = pkt
// NOTE(maxtaco) 2016.01.11
// Only register an identity once we've gotten a valid self-signature.
// It's possible therefore for us to throw away `current` in the case
// no valid self-signatures were found. That's OK as long as there are
// other identies that make sense.
//
// NOTE! We might later see a revocation for this very same UID, and it
// won't be undone. We've preserved this feature from the original
// Google OpenPGP we forked from.
e.Identities[current.Name] = current
} else {
// We really should warn that there was a failure here. Not raise an error
// since this really shouldn't be a fail-stop error.
}
} else if current != nil && pkt.SigType == packet.SigTypeIdentityRevocation {
if err = e.PrimaryKey.VerifyUserIdSignature(current.Name, e.PrimaryKey, pkt); err == nil {
// Note: we are not removing the identity from
// e.Identities. Caller can always filter by Revocation
// field to ignore revoked identities.
current.Revocation = pkt
}
} else if pkt.SigType == packet.SigTypeDirectSignature {
if err = e.PrimaryKey.VerifyRevocationSignature(e.PrimaryKey, pkt); err == nil {
if desig := pkt.DesignatedRevoker; desig != nil {
// If it's a designated revoker signature, take last 8 octects
// of fingerprint as Key ID and save it to designatedRevokers
// map. We consult this map later to see if a foreign
// revocation should be added to UnverifiedRevocations.
keyID := binary.BigEndian.Uint64(desig.Fingerprint[len(desig.Fingerprint)-8:])
designatedRevokers[keyID] = true
}
}
} else if current == nil {
// NOTE(maxtaco)
//
// See https://github.com/keybase/client/issues/2666
//
// There might have been a user attribute picture before this signature,
// in which case this is still a valid PGP key. In the future we might
// not ignore user attributes (like picture). But either way, it doesn't
// make sense to bail out here. Keep looking for other valid signatures.
//
// Used to be:
// return nil, errors.StructuralError("signature packet found before user id packet")
} else {
current.Signatures = append(current.Signatures, pkt)
}
case *packet.PrivateKey:
if pkt.IsSubkey == false {
packets.Unread(p)
break EachPacket
}
err = addSubkey(e, packets, &pkt.PublicKey, pkt)
if err != nil {
return nil, err
}
case *packet.PublicKey:
if pkt.IsSubkey == false {
packets.Unread(p)
break EachPacket
}
err = addSubkey(e, packets, pkt, nil)
if err != nil {
return nil, err
}
default:
// we ignore unknown packets
}
}
if len(e.Identities) == 0 {
return nil, errors.StructuralError("entity without any identities")
}
for _, revocation := range revocations {
if revocation.IssuerKeyId == nil || *revocation.IssuerKeyId == e.PrimaryKey.KeyId {
// Key revokes itself, something that we can verify.
err = e.PrimaryKey.VerifyRevocationSignature(e.PrimaryKey, revocation)
if err == nil {
e.Revocations = append(e.Revocations, revocation)
} else {
return nil, errors.StructuralError("revocation signature signed by alternate key")
}
} else if revocation.IssuerKeyId != nil {
if _, ok := designatedRevokers[*revocation.IssuerKeyId]; ok {
// Revocation is done by certified designated revoker,
// but we can't verify the revocation.
e.UnverifiedRevocations = append(e.UnverifiedRevocations, revocation)
}
}
}
return e, nil
}
func addSubkey(e *Entity, packets *packet.Reader, pub *packet.PublicKey, priv *packet.PrivateKey) error {
var subKey Subkey
subKey.PublicKey = pub
subKey.PrivateKey = priv
var lastErr error
for {
p, err := packets.Next()
if err == io.EOF {
break
}
if err != nil {
return errors.StructuralError("subkey signature invalid: " + err.Error())
}
sig, ok := p.(*packet.Signature)
if !ok {
// Hit a non-signature packet, so assume we're up to the next key
packets.Unread(p)
break
}
if st := sig.SigType; st != packet.SigTypeSubkeyBinding && st != packet.SigTypeSubkeyRevocation {
// Note(maxtaco):
// We used to error out here, but instead, let's fast-forward past
// packets that are in the wrong place (like misplaced 0x13 signatures)
// until we get to one that works. For a test case,
// see TestWithBadSubkeySignaturePackets.
continue
}
err = e.PrimaryKey.VerifyKeySignature(subKey.PublicKey, sig)
if err != nil {
// Non valid signature, so again, no need to abandon all hope, just continue;
// make a note of the error we hit.
lastErr = errors.StructuralError("subkey signature invalid: " + err.Error())
continue
}
switch sig.SigType {
case packet.SigTypeSubkeyBinding:
// Does the "new" sig set expiration to later date than
// "previous" sig?
if subKey.Sig == nil || subKey.Sig.ExpiresBeforeOther(sig) {
subKey.Sig = sig
}
case packet.SigTypeSubkeyRevocation:
// First writer wins
if subKey.Revocation == nil {
subKey.Revocation = sig
}
}
}
if subKey.Sig != nil {
e.Subkeys = append(e.Subkeys, subKey)
} else {
if lastErr == nil {
lastErr = errors.StructuralError("Subkey wasn't signed; expected a 'binding' signature")
}
e.BadSubkeys = append(e.BadSubkeys, BadSubkey{Subkey: subKey, Err: lastErr})
}
return nil
}
const defaultRSAKeyBits = 2048
// NewEntity returns an Entity that contains a fresh RSA/RSA keypair with a
// single identity composed of the given full name, comment and email, any of
// which may be empty but must not contain any of "()<>\x00".
// If config is nil, sensible defaults will be used.
func NewEntity(name, comment, email string, config *packet.Config) (*Entity, error) {
currentTime := config.Now()
bits := defaultRSAKeyBits
if config != nil && config.RSABits != 0 {
bits = config.RSABits
}
uid := packet.NewUserId(name, comment, email)
if uid == nil {
return nil, errors.InvalidArgumentError("user id field contained invalid characters")
}
signingPriv, err := rsa.GenerateKey(config.Random(), bits)
if err != nil {
return nil, err
}
encryptingPriv, err := rsa.GenerateKey(config.Random(), bits)
if err != nil {
return nil, err
}
e := &Entity{
PrimaryKey: packet.NewRSAPublicKey(currentTime, &signingPriv.PublicKey),
PrivateKey: packet.NewRSAPrivateKey(currentTime, signingPriv),
Identities: make(map[string]*Identity),
}
isPrimaryId := true
e.Identities[uid.Id] = &Identity{
Name: uid.Name,
UserId: uid,
SelfSignature: &packet.Signature{
CreationTime: currentTime,
SigType: packet.SigTypePositiveCert,
PubKeyAlgo: packet.PubKeyAlgoRSA,
Hash: config.Hash(),
IsPrimaryId: &isPrimaryId,
FlagsValid: true,
FlagSign: true,
FlagCertify: true,
IssuerKeyId: &e.PrimaryKey.KeyId,
},
}
e.Subkeys = make([]Subkey, 1)
e.Subkeys[0] = Subkey{
PublicKey: packet.NewRSAPublicKey(currentTime, &encryptingPriv.PublicKey),
PrivateKey: packet.NewRSAPrivateKey(currentTime, encryptingPriv),
Sig: &packet.Signature{
CreationTime: currentTime,
SigType: packet.SigTypeSubkeyBinding,
PubKeyAlgo: packet.PubKeyAlgoRSA,
Hash: config.Hash(),
FlagsValid: true,
FlagEncryptStorage: true,
FlagEncryptCommunications: true,
IssuerKeyId: &e.PrimaryKey.KeyId,
},
}
e.Subkeys[0].PublicKey.IsSubkey = true
e.Subkeys[0].PrivateKey.IsSubkey = true
return e, nil
}
// SerializePrivate serializes an Entity, including private key material, to
// the given Writer. For now, it must only be used on an Entity returned from
// NewEntity.
// If config is nil, sensible defaults will be used.
func (e *Entity) SerializePrivate(w io.Writer, config *packet.Config) (err error) {
err = e.PrivateKey.Serialize(w)
if err != nil {
return
}
for _, ident := range e.Identities {
err = ident.UserId.Serialize(w)
if err != nil {
return
}
if e.PrivateKey.PrivateKey != nil {
err = ident.SelfSignature.SignUserId(ident.UserId.Id, e.PrimaryKey, e.PrivateKey, config)
if err != nil {
return
}
}
err = ident.SelfSignature.Serialize(w)
if err != nil {
return
}
}
for _, subkey := range e.Subkeys {
err = subkey.PrivateKey.Serialize(w)
if err != nil {
return
}
// Workaround shortcoming of SignKey(), which doesn't work to reverse-sign
// sub-signing keys. So if requested, just reuse the signatures already
// available to us (if we read this key from a keyring).
if e.PrivateKey.PrivateKey != nil && !config.ReuseSignatures() {
err = subkey.Sig.SignKey(subkey.PublicKey, e.PrivateKey, config)
if err != nil {
return
}
}
if subkey.Revocation != nil {
err = subkey.Revocation.Serialize(w)
if err != nil {
return
}
}
err = subkey.Sig.Serialize(w)
if err != nil {
return
}
}
return nil
}
// Serialize writes the public part of the given Entity to w. (No private
// key material will be output).
func (e *Entity) Serialize(w io.Writer) error {
err := e.PrimaryKey.Serialize(w)
if err != nil {
return err
}
for _, ident := range e.Identities {
err = ident.UserId.Serialize(w)
if err != nil {
return err
}
err = ident.SelfSignature.Serialize(w)
if err != nil {
return err
}
for _, sig := range ident.Signatures {
err = sig.Serialize(w)
if err != nil {
return err
}
}
}
for _, subkey := range e.Subkeys {
err = subkey.PublicKey.Serialize(w)
if err != nil {
return err
}
if subkey.Revocation != nil {
err = subkey.Revocation.Serialize(w)
if err != nil {
return err
}
}
err = subkey.Sig.Serialize(w)
if err != nil {
return err
}
}
return nil
}
// SignIdentity adds a signature to e, from signer, attesting that identity is
// associated with e. The provided identity must already be an element of
// e.Identities and the private key of signer must have been decrypted if
// necessary.
// If config is nil, sensible defaults will be used.
func (e *Entity) SignIdentity(identity string, signer *Entity, config *packet.Config) error {
if signer.PrivateKey == nil {
return errors.InvalidArgumentError("signing Entity must have a private key")
}
if signer.PrivateKey.Encrypted {
return errors.InvalidArgumentError("signing Entity's private key must be decrypted")
}
ident, ok := e.Identities[identity]
if !ok {
return errors.InvalidArgumentError("given identity string not found in Entity")
}
sig := &packet.Signature{
SigType: packet.SigTypeGenericCert,
PubKeyAlgo: signer.PrivateKey.PubKeyAlgo,
Hash: config.Hash(),
CreationTime: config.Now(),
IssuerKeyId: &signer.PrivateKey.KeyId,
}
if err := sig.SignUserId(identity, e.PrimaryKey, signer.PrivateKey, config); err != nil {
return err
}
ident.Signatures = append(ident.Signatures, sig)
return nil
}
// CopySubkeyRevocations copies subkey revocations from the src Entity over
// to the receiver entity. We need this because `gpg --export-secret-key` does
// not appear to output subkey revocations. In this case we need to manually
// merge with the output of `gpg --export`.
func (e *Entity) CopySubkeyRevocations(src *Entity) {
m := make(map[[20]byte]*packet.Signature)
for _, subkey := range src.Subkeys {
if subkey.Revocation != nil {
m[subkey.PublicKey.Fingerprint] = subkey.Revocation
}
}
for i, subkey := range e.Subkeys {
if r := m[subkey.PublicKey.Fingerprint]; r != nil {
e.Subkeys[i].Revocation = r
}
}
}
// CheckDesignatedRevokers will try to confirm any of designated
// revocation of entity. For this function to work, revocation
// issuer's key should be found in keyring. First successfully
// verified designated revocation is returned along with the key that
// verified it.
func FindVerifiedDesignatedRevoke(keyring KeyRing, entity *Entity) (*packet.Signature, *Key) {
for _, sig := range entity.UnverifiedRevocations {
if sig.IssuerKeyId == nil {
continue
}
issuerKeyId := *sig.IssuerKeyId
issuerFingerprint := sig.IssuerFingerprint
keys := keyring.KeysByIdUsage(issuerKeyId, issuerFingerprint, packet.KeyFlagSign)
if len(keys) == 0 {
continue
}
for _, key := range keys {
err := key.PublicKey.VerifyRevocationSignature(entity.PrimaryKey, sig)
if err == nil {
return sig, &key
}
}
}
return nil, nil
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"compress/bzip2"
"compress/flate"
"compress/zlib"
"io"
"strconv"
"github.com/keybase/go-crypto/openpgp/errors"
)
// Compressed represents a compressed OpenPGP packet. The decompressed contents
// will contain more OpenPGP packets. See RFC 4880, section 5.6.
type Compressed struct {
Body io.Reader
}
const (
NoCompression = flate.NoCompression
BestSpeed = flate.BestSpeed
BestCompression = flate.BestCompression
DefaultCompression = flate.DefaultCompression
)
// CompressionConfig contains compressor configuration settings.
type CompressionConfig struct {
// Level is the compression level to use. It must be set to
// between -1 and 9, with -1 causing the compressor to use the
// default compression level, 0 causing the compressor to use
// no compression and 1 to 9 representing increasing (better,
// slower) compression levels. If Level is less than -1 or
// more then 9, a non-nil error will be returned during
// encryption. See the constants above for convenient common
// settings for Level.
Level int
}
func (c *Compressed) parse(r io.Reader) error {
var buf [1]byte
_, err := readFull(r, buf[:])
if err != nil {
return err
}
switch buf[0] {
case 1:
c.Body = flate.NewReader(r)
case 2:
c.Body, err = zlib.NewReader(r)
case 3:
c.Body = bzip2.NewReader(r)
default:
err = errors.UnsupportedError("unknown compression algorithm: " + strconv.Itoa(int(buf[0])))
}
return err
}
// compressedWriterCloser represents the serialized compression stream
// header and the compressor. Its Close() method ensures that both the
// compressor and serialized stream header are closed. Its Write()
// method writes to the compressor.
type compressedWriteCloser struct {
sh io.Closer // Stream Header
c io.WriteCloser // Compressor
}
func (cwc compressedWriteCloser) Write(p []byte) (int, error) {
return cwc.c.Write(p)
}
func (cwc compressedWriteCloser) Close() (err error) {
err = cwc.c.Close()
if err != nil {
return err
}
return cwc.sh.Close()
}
// SerializeCompressed serializes a compressed data packet to w and
// returns a WriteCloser to which the literal data packets themselves
// can be written and which MUST be closed on completion. If cc is
// nil, sensible defaults will be used to configure the compression
// algorithm.
func SerializeCompressed(w io.WriteCloser, algo CompressionAlgo, cc *CompressionConfig) (literaldata io.WriteCloser, err error) {
compressed, err := serializeStreamHeader(w, packetTypeCompressed)
if err != nil {
return
}
_, err = compressed.Write([]byte{uint8(algo)})
if err != nil {
return
}
level := DefaultCompression
if cc != nil {
level = cc.Level
}
var compressor io.WriteCloser
switch algo {
case CompressionZIP:
compressor, err = flate.NewWriter(compressed, level)
case CompressionZLIB:
compressor, err = zlib.NewWriterLevel(compressed, level)
default:
s := strconv.Itoa(int(algo))
err = errors.UnsupportedError("Unsupported compression algorithm: " + s)
}
if err != nil {
return
}
literaldata = compressedWriteCloser{compressed, compressor}
return
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"crypto"
"crypto/rand"
"io"
"time"
)
// Config collects a number of parameters along with sensible defaults.
// A nil *Config is valid and results in all default values.
type Config struct {
// Rand provides the source of entropy.
// If nil, the crypto/rand Reader is used.
Rand io.Reader
// DefaultHash is the default hash function to be used.
// If zero, SHA-256 is used.
DefaultHash crypto.Hash
// DefaultCipher is the cipher to be used.
// If zero, AES-128 is used.
DefaultCipher CipherFunction
// Time returns the current time as the number of seconds since the
// epoch. If Time is nil, time.Now is used.
Time func() time.Time
// DefaultCompressionAlgo is the compression algorithm to be
// applied to the plaintext before encryption. If zero, no
// compression is done.
DefaultCompressionAlgo CompressionAlgo
// CompressionConfig configures the compression settings.
CompressionConfig *CompressionConfig
// S2KCount is only used for symmetric encryption. It
// determines the strength of the passphrase stretching when
// the said passphrase is hashed to produce a key. S2KCount
// should be between 1024 and 65011712, inclusive. If Config
// is nil or S2KCount is 0, the value 65536 used. Not all
// values in the above range can be represented. S2KCount will
// be rounded up to the next representable value if it cannot
// be encoded exactly. When set, it is strongly encrouraged to
// use a value that is at least 65536. See RFC 4880 Section
// 3.7.1.3.
S2KCount int
// RSABits is the number of bits in new RSA keys made with NewEntity.
// If zero, then 2048 bit keys are created.
RSABits int
// ReuseSignatures tells us to reuse existing Signatures
// on serialized output.
ReuseSignaturesOnSerialize bool
}
func (c *Config) Random() io.Reader {
if c == nil || c.Rand == nil {
return rand.Reader
}
return c.Rand
}
func (c *Config) Hash() crypto.Hash {
if c == nil || uint(c.DefaultHash) == 0 {
return crypto.SHA256
}
return c.DefaultHash
}
func (c *Config) Cipher() CipherFunction {
if c == nil || uint8(c.DefaultCipher) == 0 {
return CipherAES128
}
return c.DefaultCipher
}
func (c *Config) Now() time.Time {
if c == nil || c.Time == nil {
return time.Now()
}
return c.Time()
}
func (c *Config) Compression() CompressionAlgo {
if c == nil {
return CompressionNone
}
return c.DefaultCompressionAlgo
}
func (c *Config) PasswordHashIterations() int {
if c == nil || c.S2KCount == 0 {
return 0
}
return c.S2KCount
}
func (c *Config) ReuseSignatures() bool {
return c != nil && c.ReuseSignaturesOnSerialize
}

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package packet
import (
"bytes"
"io"
"math/big"
"github.com/keybase/go-crypto/openpgp/ecdh"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/s2k"
)
// ECDHKdfParams generates KDF parameters sequence for given
// PublicKey. See https://tools.ietf.org/html/rfc6637#section-8
func ECDHKdfParams(pub *PublicKey) []byte {
buf := new(bytes.Buffer)
oid := pub.ec.oid
buf.WriteByte(byte(len(oid)))
buf.Write(oid)
buf.WriteByte(18) // ECDH TYPE
pub.ecdh.serialize(buf)
buf.WriteString("Anonymous Sender ")
buf.Write(pub.Fingerprint[:])
return buf.Bytes()
}
func decryptKeyECDH(priv *PrivateKey, X, Y *big.Int, C []byte) (out []byte, err error) {
ecdhpriv, ok := priv.PrivateKey.(*ecdh.PrivateKey)
if !ok {
return nil, errors.InvalidArgumentError("bad internal ECDH key")
}
Sx := ecdhpriv.DecryptShared(X, Y)
kdfParams := ECDHKdfParams(&priv.PublicKey)
hash, ok := s2k.HashIdToHash(byte(priv.ecdh.KdfHash))
if !ok {
return nil, errors.InvalidArgumentError("invalid hash id in private key")
}
key := ecdhpriv.KDF(Sx, kdfParams, hash)
keySize := CipherFunction(priv.ecdh.KdfAlgo).KeySize()
decrypted, err := ecdh.AESKeyUnwrap(key[:keySize], C)
if err != nil {
return nil, err
}
// We have to "read ahead" to discover real length of the
// encryption key and properly unpad buffer.
cipherFunc := CipherFunction(decrypted[0])
// +3 bytes = 1-byte cipher id and checksum 2-byte checksum.
out = ecdh.UnpadBuffer(decrypted, cipherFunc.KeySize()+3)
if out == nil {
return nil, errors.InvalidArgumentError("invalid padding while ECDH")
}
return out, nil
}
func serializeEncryptedKeyECDH(w io.Writer, rand io.Reader, header [10]byte, pub *PublicKey, keyBlock []byte) error {
ecdhpub := pub.PublicKey.(*ecdh.PublicKey)
kdfParams := ECDHKdfParams(pub)
hash, ok := s2k.HashIdToHash(byte(pub.ecdh.KdfHash))
if !ok {
return errors.InvalidArgumentError("invalid hash id in private key")
}
kdfKeySize := CipherFunction(pub.ecdh.KdfAlgo).KeySize()
Vx, Vy, C, err := ecdhpub.Encrypt(rand, kdfParams, keyBlock, hash, kdfKeySize)
if err != nil {
return err
}
mpis, mpiBitLen := ecdh.Marshal(ecdhpub.Curve, Vx, Vy)
packetLen := len(header) /* header length in bytes */
packetLen += 2 /* mpi length in bits */ + len(mpis)
packetLen += 1 /* ciphertext size in bytes */ + len(C)
err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
if err != nil {
return err
}
_, err = w.Write(header[:])
if err != nil {
return err
}
_, err = w.Write([]byte{byte(mpiBitLen >> 8), byte(mpiBitLen)})
if err != nil {
return err
}
_, err = w.Write(mpis[:])
if err != nil {
return err
}
w.Write([]byte{byte(len(C))})
w.Write(C[:])
return nil
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"encoding/binary"
"io"
"math/big"
"strconv"
"github.com/keybase/go-crypto/openpgp/ecdh"
"github.com/keybase/go-crypto/openpgp/elgamal"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/rsa"
)
const encryptedKeyVersion = 3
// EncryptedKey represents a public-key encrypted session key. See RFC 4880,
// section 5.1.
type EncryptedKey struct {
KeyId uint64
Algo PublicKeyAlgorithm
CipherFunc CipherFunction // only valid after a successful Decrypt
Key []byte // only valid after a successful Decrypt
encryptedMPI1, encryptedMPI2 parsedMPI
ecdh_C []byte
}
func (e *EncryptedKey) parse(r io.Reader) (err error) {
var buf [10]byte
_, err = readFull(r, buf[:])
if err != nil {
return
}
if buf[0] != encryptedKeyVersion {
return errors.UnsupportedError("unknown EncryptedKey version " + strconv.Itoa(int(buf[0])))
}
e.KeyId = binary.BigEndian.Uint64(buf[1:9])
e.Algo = PublicKeyAlgorithm(buf[9])
switch e.Algo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
e.encryptedMPI1.bytes, e.encryptedMPI1.bitLength, err = readMPI(r)
case PubKeyAlgoElGamal:
e.encryptedMPI1.bytes, e.encryptedMPI1.bitLength, err = readMPI(r)
if err != nil {
return
}
e.encryptedMPI2.bytes, e.encryptedMPI2.bitLength, err = readMPI(r)
case PubKeyAlgoECDH:
e.encryptedMPI1.bytes, e.encryptedMPI1.bitLength, err = readMPI(r)
if err != nil {
return err
}
_, err = readFull(r, buf[:1]) // read C len (1 byte)
if err != nil {
return err
}
e.ecdh_C = make([]byte, int(buf[0]))
_, err = readFull(r, e.ecdh_C)
}
if err != nil {
return err
}
_, err = consumeAll(r)
return err
}
func checksumKeyMaterial(key []byte) uint16 {
var checksum uint16
for _, v := range key {
checksum += uint16(v)
}
return checksum
}
// Decrypt decrypts an encrypted session key with the given private key. The
// private key must have been decrypted first.
// If config is nil, sensible defaults will be used.
func (e *EncryptedKey) Decrypt(priv *PrivateKey, config *Config) error {
var err error
var b []byte
// TODO(agl): use session key decryption routines here to avoid
// padding oracle attacks.
switch priv.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
b, err = rsa.DecryptPKCS1v15(config.Random(), priv.PrivateKey.(*rsa.PrivateKey), e.encryptedMPI1.bytes)
case PubKeyAlgoElGamal:
c1 := new(big.Int).SetBytes(e.encryptedMPI1.bytes)
c2 := new(big.Int).SetBytes(e.encryptedMPI2.bytes)
b, err = elgamal.Decrypt(priv.PrivateKey.(*elgamal.PrivateKey), c1, c2)
case PubKeyAlgoECDH:
// Note: Unmarshal checks if point is on the curve.
c1, c2 := ecdh.Unmarshal(priv.PrivateKey.(*ecdh.PrivateKey).Curve, e.encryptedMPI1.bytes)
if c1 == nil {
return errors.InvalidArgumentError("failed to parse EC point for encryption key")
}
b, err = decryptKeyECDH(priv, c1, c2, e.ecdh_C)
default:
err = errors.InvalidArgumentError("cannot decrypted encrypted session key with private key of type " + strconv.Itoa(int(priv.PubKeyAlgo)))
}
if err != nil {
return err
}
e.CipherFunc = CipherFunction(b[0])
e.Key = b[1 : len(b)-2]
expectedChecksum := uint16(b[len(b)-2])<<8 | uint16(b[len(b)-1])
checksum := checksumKeyMaterial(e.Key)
if checksum != expectedChecksum {
return errors.StructuralError("EncryptedKey checksum incorrect")
}
return nil
}
// Serialize writes the encrypted key packet, e, to w.
func (e *EncryptedKey) Serialize(w io.Writer) error {
var mpiLen int
switch e.Algo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
mpiLen = 2 + len(e.encryptedMPI1.bytes)
case PubKeyAlgoElGamal:
mpiLen = 2 + len(e.encryptedMPI1.bytes) + 2 + len(e.encryptedMPI2.bytes)
default:
return errors.InvalidArgumentError("don't know how to serialize encrypted key type " + strconv.Itoa(int(e.Algo)))
}
serializeHeader(w, packetTypeEncryptedKey, 1 /* version */ +8 /* key id */ +1 /* algo */ +mpiLen)
w.Write([]byte{encryptedKeyVersion})
binary.Write(w, binary.BigEndian, e.KeyId)
w.Write([]byte{byte(e.Algo)})
switch e.Algo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
writeMPIs(w, e.encryptedMPI1)
case PubKeyAlgoElGamal:
writeMPIs(w, e.encryptedMPI1, e.encryptedMPI2)
default:
panic("internal error")
}
return nil
}
// SerializeEncryptedKey serializes an encrypted key packet to w that contains
// key, encrypted to pub.
// If config is nil, sensible defaults will be used.
func SerializeEncryptedKey(w io.Writer, pub *PublicKey, cipherFunc CipherFunction, key []byte, config *Config) error {
var buf [10]byte
buf[0] = encryptedKeyVersion
binary.BigEndian.PutUint64(buf[1:9], pub.KeyId)
buf[9] = byte(pub.PubKeyAlgo)
keyBlock := make([]byte, 1 /* cipher type */ +len(key)+2 /* checksum */)
keyBlock[0] = byte(cipherFunc)
copy(keyBlock[1:], key)
checksum := checksumKeyMaterial(key)
keyBlock[1+len(key)] = byte(checksum >> 8)
keyBlock[1+len(key)+1] = byte(checksum)
switch pub.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
return serializeEncryptedKeyRSA(w, config.Random(), buf, pub.PublicKey.(*rsa.PublicKey), keyBlock)
case PubKeyAlgoElGamal:
return serializeEncryptedKeyElGamal(w, config.Random(), buf, pub.PublicKey.(*elgamal.PublicKey), keyBlock)
case PubKeyAlgoECDH:
return serializeEncryptedKeyECDH(w, config.Random(), buf, pub, keyBlock)
case PubKeyAlgoDSA, PubKeyAlgoRSASignOnly:
return errors.InvalidArgumentError("cannot encrypt to public key of type " + strconv.Itoa(int(pub.PubKeyAlgo)))
}
return errors.UnsupportedError("encrypting a key to public key of type " + strconv.Itoa(int(pub.PubKeyAlgo)))
}
func serializeEncryptedKeyRSA(w io.Writer, rand io.Reader, header [10]byte, pub *rsa.PublicKey, keyBlock []byte) error {
cipherText, err := rsa.EncryptPKCS1v15(rand, pub, keyBlock)
if err != nil {
return errors.InvalidArgumentError("RSA encryption failed: " + err.Error())
}
packetLen := 10 /* header length */ + 2 /* mpi size */ + len(cipherText)
err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
if err != nil {
return err
}
_, err = w.Write(header[:])
if err != nil {
return err
}
return writeMPI(w, 8*uint16(len(cipherText)), cipherText)
}
func serializeEncryptedKeyElGamal(w io.Writer, rand io.Reader, header [10]byte, pub *elgamal.PublicKey, keyBlock []byte) error {
c1, c2, err := elgamal.Encrypt(rand, pub, keyBlock)
if err != nil {
return errors.InvalidArgumentError("ElGamal encryption failed: " + err.Error())
}
packetLen := 10 /* header length */
packetLen += 2 /* mpi size */ + (c1.BitLen()+7)/8
packetLen += 2 /* mpi size */ + (c2.BitLen()+7)/8
err = serializeHeader(w, packetTypeEncryptedKey, packetLen)
if err != nil {
return err
}
_, err = w.Write(header[:])
if err != nil {
return err
}
err = writeBig(w, c1)
if err != nil {
return err
}
return writeBig(w, c2)
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"encoding/binary"
"io"
)
// LiteralData represents an encrypted file. See RFC 4880, section 5.9.
type LiteralData struct {
IsBinary bool
FileName string
Time uint32 // Unix epoch time. Either creation time or modification time. 0 means undefined.
Body io.Reader
}
// ForEyesOnly returns whether the contents of the LiteralData have been marked
// as especially sensitive.
func (l *LiteralData) ForEyesOnly() bool {
return l.FileName == "_CONSOLE"
}
func (l *LiteralData) parse(r io.Reader) (err error) {
var buf [256]byte
_, err = readFull(r, buf[:2])
if err != nil {
return
}
l.IsBinary = buf[0] == 'b'
fileNameLen := int(buf[1])
_, err = readFull(r, buf[:fileNameLen])
if err != nil {
return
}
l.FileName = string(buf[:fileNameLen])
_, err = readFull(r, buf[:4])
if err != nil {
return
}
l.Time = binary.BigEndian.Uint32(buf[:4])
l.Body = r
return
}
// SerializeLiteral serializes a literal data packet to w and returns a
// WriteCloser to which the data itself can be written and which MUST be closed
// on completion. The fileName is truncated to 255 bytes.
func SerializeLiteral(w io.WriteCloser, isBinary bool, fileName string, time uint32) (plaintext io.WriteCloser, err error) {
var buf [4]byte
buf[0] = 't'
if isBinary {
buf[0] = 'b'
}
if len(fileName) > 255 {
fileName = fileName[:255]
}
buf[1] = byte(len(fileName))
inner, err := serializeStreamHeader(w, packetTypeLiteralData)
if err != nil {
return
}
_, err = inner.Write(buf[:2])
if err != nil {
return
}
_, err = inner.Write([]byte(fileName))
if err != nil {
return
}
binary.BigEndian.PutUint32(buf[:], time)
_, err = inner.Write(buf[:])
if err != nil {
return
}
plaintext = inner
return
}

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// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// OpenPGP CFB Mode. http://tools.ietf.org/html/rfc4880#section-13.9
package packet
import (
"crypto/cipher"
)
type ocfbEncrypter struct {
b cipher.Block
fre []byte
outUsed int
}
// An OCFBResyncOption determines if the "resynchronization step" of OCFB is
// performed.
type OCFBResyncOption bool
const (
OCFBResync OCFBResyncOption = true
OCFBNoResync OCFBResyncOption = false
)
// NewOCFBEncrypter returns a cipher.Stream which encrypts data with OpenPGP's
// cipher feedback mode using the given cipher.Block, and an initial amount of
// ciphertext. randData must be random bytes and be the same length as the
// cipher.Block's block size. Resync determines if the "resynchronization step"
// from RFC 4880, 13.9 step 7 is performed. Different parts of OpenPGP vary on
// this point.
func NewOCFBEncrypter(block cipher.Block, randData []byte, resync OCFBResyncOption) (cipher.Stream, []byte) {
blockSize := block.BlockSize()
if len(randData) != blockSize {
return nil, nil
}
x := &ocfbEncrypter{
b: block,
fre: make([]byte, blockSize),
outUsed: 0,
}
prefix := make([]byte, blockSize+2)
block.Encrypt(x.fre, x.fre)
for i := 0; i < blockSize; i++ {
prefix[i] = randData[i] ^ x.fre[i]
}
block.Encrypt(x.fre, prefix[:blockSize])
prefix[blockSize] = x.fre[0] ^ randData[blockSize-2]
prefix[blockSize+1] = x.fre[1] ^ randData[blockSize-1]
if resync {
block.Encrypt(x.fre, prefix[2:])
} else {
x.fre[0] = prefix[blockSize]
x.fre[1] = prefix[blockSize+1]
x.outUsed = 2
}
return x, prefix
}
func (x *ocfbEncrypter) XORKeyStream(dst, src []byte) {
for i := 0; i < len(src); i++ {
if x.outUsed == len(x.fre) {
x.b.Encrypt(x.fre, x.fre)
x.outUsed = 0
}
x.fre[x.outUsed] ^= src[i]
dst[i] = x.fre[x.outUsed]
x.outUsed++
}
}
type ocfbDecrypter struct {
b cipher.Block
fre []byte
outUsed int
}
// NewOCFBDecrypter returns a cipher.Stream which decrypts data with OpenPGP's
// cipher feedback mode using the given cipher.Block. Prefix must be the first
// blockSize + 2 bytes of the ciphertext, where blockSize is the cipher.Block's
// block size. If an incorrect key is detected then nil is returned. On
// successful exit, blockSize+2 bytes of decrypted data are written into
// prefix. Resync determines if the "resynchronization step" from RFC 4880,
// 13.9 step 7 is performed. Different parts of OpenPGP vary on this point.
func NewOCFBDecrypter(block cipher.Block, prefix []byte, resync OCFBResyncOption) cipher.Stream {
blockSize := block.BlockSize()
if len(prefix) != blockSize+2 {
return nil
}
x := &ocfbDecrypter{
b: block,
fre: make([]byte, blockSize),
outUsed: 0,
}
prefixCopy := make([]byte, len(prefix))
copy(prefixCopy, prefix)
block.Encrypt(x.fre, x.fre)
for i := 0; i < blockSize; i++ {
prefixCopy[i] ^= x.fre[i]
}
block.Encrypt(x.fre, prefix[:blockSize])
prefixCopy[blockSize] ^= x.fre[0]
prefixCopy[blockSize+1] ^= x.fre[1]
if prefixCopy[blockSize-2] != prefixCopy[blockSize] ||
prefixCopy[blockSize-1] != prefixCopy[blockSize+1] {
return nil
}
if resync {
block.Encrypt(x.fre, prefix[2:])
} else {
x.fre[0] = prefix[blockSize]
x.fre[1] = prefix[blockSize+1]
x.outUsed = 2
}
copy(prefix, prefixCopy)
return x
}
func (x *ocfbDecrypter) XORKeyStream(dst, src []byte) {
for i := 0; i < len(src); i++ {
if x.outUsed == len(x.fre) {
x.b.Encrypt(x.fre, x.fre)
x.outUsed = 0
}
c := src[i]
dst[i] = x.fre[x.outUsed] ^ src[i]
x.fre[x.outUsed] = c
x.outUsed++
}
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"crypto"
"encoding/binary"
"io"
"strconv"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/s2k"
)
// OnePassSignature represents a one-pass signature packet. See RFC 4880,
// section 5.4.
type OnePassSignature struct {
SigType SignatureType
Hash crypto.Hash
PubKeyAlgo PublicKeyAlgorithm
KeyId uint64
IsLast bool
}
const onePassSignatureVersion = 3
func (ops *OnePassSignature) parse(r io.Reader) (err error) {
var buf [13]byte
_, err = readFull(r, buf[:])
if err != nil {
return
}
if buf[0] != onePassSignatureVersion {
err = errors.UnsupportedError("one-pass-signature packet version " + strconv.Itoa(int(buf[0])))
}
var ok bool
ops.Hash, ok = s2k.HashIdToHash(buf[2])
if !ok {
return errors.UnsupportedError("hash function: " + strconv.Itoa(int(buf[2])))
}
ops.SigType = SignatureType(buf[1])
ops.PubKeyAlgo = PublicKeyAlgorithm(buf[3])
ops.KeyId = binary.BigEndian.Uint64(buf[4:12])
ops.IsLast = buf[12] != 0
return
}
// Serialize marshals the given OnePassSignature to w.
func (ops *OnePassSignature) Serialize(w io.Writer) error {
var buf [13]byte
buf[0] = onePassSignatureVersion
buf[1] = uint8(ops.SigType)
var ok bool
buf[2], ok = s2k.HashToHashId(ops.Hash)
if !ok {
return errors.UnsupportedError("hash type: " + strconv.Itoa(int(ops.Hash)))
}
buf[3] = uint8(ops.PubKeyAlgo)
binary.BigEndian.PutUint64(buf[4:12], ops.KeyId)
if ops.IsLast {
buf[12] = 1
}
if err := serializeHeader(w, packetTypeOnePassSignature, len(buf)); err != nil {
return err
}
_, err := w.Write(buf[:])
return err
}

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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"io"
"io/ioutil"
"github.com/keybase/go-crypto/openpgp/errors"
)
// OpaquePacket represents an OpenPGP packet as raw, unparsed data. This is
// useful for splitting and storing the original packet contents separately,
// handling unsupported packet types or accessing parts of the packet not yet
// implemented by this package.
type OpaquePacket struct {
// Packet type
Tag uint8
// Reason why the packet was parsed opaquely
Reason error
// Binary contents of the packet data
Contents []byte
}
func (op *OpaquePacket) parse(r io.Reader) (err error) {
op.Contents, err = ioutil.ReadAll(r)
return
}
// Serialize marshals the packet to a writer in its original form, including
// the packet header.
func (op *OpaquePacket) Serialize(w io.Writer) (err error) {
err = serializeHeader(w, packetType(op.Tag), len(op.Contents))
if err == nil {
_, err = w.Write(op.Contents)
}
return
}
// Parse attempts to parse the opaque contents into a structure supported by
// this package. If the packet is not known then the result will be another
// OpaquePacket.
func (op *OpaquePacket) Parse() (p Packet, err error) {
hdr := bytes.NewBuffer(nil)
err = serializeHeader(hdr, packetType(op.Tag), len(op.Contents))
if err != nil {
op.Reason = err
return op, err
}
p, err = Read(io.MultiReader(hdr, bytes.NewBuffer(op.Contents)))
if err != nil {
op.Reason = err
p = op
}
return
}
// OpaqueReader reads OpaquePackets from an io.Reader.
type OpaqueReader struct {
r io.Reader
}
func NewOpaqueReader(r io.Reader) *OpaqueReader {
return &OpaqueReader{r: r}
}
// Read the next OpaquePacket.
func (or *OpaqueReader) Next() (op *OpaquePacket, err error) {
tag, _, contents, err := readHeader(or.r)
if err != nil {
return
}
op = &OpaquePacket{Tag: uint8(tag), Reason: err}
err = op.parse(contents)
if err != nil {
consumeAll(contents)
}
return
}
// OpaqueSubpacket represents an unparsed OpenPGP subpacket,
// as found in signature and user attribute packets.
type OpaqueSubpacket struct {
SubType uint8
Contents []byte
}
// OpaqueSubpackets extracts opaque, unparsed OpenPGP subpackets from
// their byte representation.
func OpaqueSubpackets(contents []byte) (result []*OpaqueSubpacket, err error) {
var (
subHeaderLen int
subPacket *OpaqueSubpacket
)
for len(contents) > 0 {
subHeaderLen, subPacket, err = nextSubpacket(contents)
if err != nil {
break
}
result = append(result, subPacket)
contents = contents[subHeaderLen+len(subPacket.Contents):]
}
return
}
func nextSubpacket(contents []byte) (subHeaderLen int, subPacket *OpaqueSubpacket, err error) {
// RFC 4880, section 5.2.3.1
var subLen uint32
if len(contents) < 1 {
goto Truncated
}
subPacket = &OpaqueSubpacket{}
switch {
case contents[0] < 192:
subHeaderLen = 2 // 1 length byte, 1 subtype byte
if len(contents) < subHeaderLen {
goto Truncated
}
subLen = uint32(contents[0])
contents = contents[1:]
case contents[0] < 255:
subHeaderLen = 3 // 2 length bytes, 1 subtype
if len(contents) < subHeaderLen {
goto Truncated
}
subLen = uint32(contents[0]-192)<<8 + uint32(contents[1]) + 192
contents = contents[2:]
default:
subHeaderLen = 6 // 5 length bytes, 1 subtype
if len(contents) < subHeaderLen {
goto Truncated
}
subLen = uint32(contents[1])<<24 |
uint32(contents[2])<<16 |
uint32(contents[3])<<8 |
uint32(contents[4])
contents = contents[5:]
}
if subLen > uint32(len(contents)) || subLen == 0 {
goto Truncated
}
subPacket.SubType = contents[0]
subPacket.Contents = contents[1:subLen]
return
Truncated:
err = errors.StructuralError("subpacket truncated")
return
}
func (osp *OpaqueSubpacket) Serialize(w io.Writer) (err error) {
buf := make([]byte, 6)
n := serializeSubpacketLength(buf, len(osp.Contents)+1)
buf[n] = osp.SubType
if _, err = w.Write(buf[:n+1]); err != nil {
return
}
_, err = w.Write(osp.Contents)
return
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package packet implements parsing and serialization of OpenPGP packets, as
// specified in RFC 4880.
package packet // import "github.com/keybase/go-crypto/openpgp/packet"
import (
"bufio"
"crypto/aes"
"crypto/cipher"
"crypto/des"
"crypto/elliptic"
"io"
"math/big"
"github.com/keybase/go-crypto/cast5"
"github.com/keybase/go-crypto/openpgp/errors"
)
// readFull is the same as io.ReadFull except that reading zero bytes returns
// ErrUnexpectedEOF rather than EOF.
func readFull(r io.Reader, buf []byte) (n int, err error) {
n, err = io.ReadFull(r, buf)
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return
}
// readLength reads an OpenPGP length from r. See RFC 4880, section 4.2.2.
func readLength(r io.Reader) (length int64, isPartial bool, err error) {
var buf [4]byte
_, err = readFull(r, buf[:1])
if err != nil {
return
}
switch {
case buf[0] < 192:
length = int64(buf[0])
case buf[0] < 224:
length = int64(buf[0]-192) << 8
_, err = readFull(r, buf[0:1])
if err != nil {
return
}
length += int64(buf[0]) + 192
case buf[0] < 255:
length = int64(1) << (buf[0] & 0x1f)
isPartial = true
default:
_, err = readFull(r, buf[0:4])
if err != nil {
return
}
length = int64(buf[0])<<24 |
int64(buf[1])<<16 |
int64(buf[2])<<8 |
int64(buf[3])
}
return
}
// partialLengthReader wraps an io.Reader and handles OpenPGP partial lengths.
// The continuation lengths are parsed and removed from the stream and EOF is
// returned at the end of the packet. See RFC 4880, section 4.2.2.4.
type partialLengthReader struct {
r io.Reader
remaining int64
isPartial bool
}
func (r *partialLengthReader) Read(p []byte) (n int, err error) {
for r.remaining == 0 {
if !r.isPartial {
return 0, io.EOF
}
r.remaining, r.isPartial, err = readLength(r.r)
if err != nil {
return 0, err
}
}
toRead := int64(len(p))
if toRead > r.remaining {
toRead = r.remaining
}
n, err = r.r.Read(p[:int(toRead)])
r.remaining -= int64(n)
if n < int(toRead) && err == io.EOF {
err = io.ErrUnexpectedEOF
}
return
}
// partialLengthWriter writes a stream of data using OpenPGP partial lengths.
// See RFC 4880, section 4.2.2.4.
type partialLengthWriter struct {
w io.WriteCloser
lengthByte [1]byte
}
func (w *partialLengthWriter) Write(p []byte) (n int, err error) {
for len(p) > 0 {
for power := uint(14); power < 32; power-- {
l := 1 << power
if len(p) >= l {
w.lengthByte[0] = 224 + uint8(power)
_, err = w.w.Write(w.lengthByte[:])
if err != nil {
return
}
var m int
m, err = w.w.Write(p[:l])
n += m
if err != nil {
return
}
p = p[l:]
break
}
}
}
return
}
func (w *partialLengthWriter) Close() error {
w.lengthByte[0] = 0
_, err := w.w.Write(w.lengthByte[:])
if err != nil {
return err
}
return w.w.Close()
}
// A spanReader is an io.LimitReader, but it returns ErrUnexpectedEOF if the
// underlying Reader returns EOF before the limit has been reached.
type spanReader struct {
r io.Reader
n int64
}
func (l *spanReader) Read(p []byte) (n int, err error) {
if l.n <= 0 {
return 0, io.EOF
}
if int64(len(p)) > l.n {
p = p[0:l.n]
}
n, err = l.r.Read(p)
l.n -= int64(n)
if l.n > 0 && err == io.EOF {
err = io.ErrUnexpectedEOF
}
return
}
// readHeader parses a packet header and returns an io.Reader which will return
// the contents of the packet. See RFC 4880, section 4.2.
func readHeader(r io.Reader) (tag packetType, length int64, contents io.Reader, err error) {
var buf [4]byte
_, err = io.ReadFull(r, buf[:1])
if err != nil {
return
}
if buf[0]&0x80 == 0 {
err = errors.StructuralError("tag byte does not have MSB set")
return
}
if buf[0]&0x40 == 0 {
// Old format packet
tag = packetType((buf[0] & 0x3f) >> 2)
lengthType := buf[0] & 3
if lengthType == 3 {
length = -1
contents = r
return
}
lengthBytes := 1 << lengthType
_, err = readFull(r, buf[0:lengthBytes])
if err != nil {
return
}
for i := 0; i < lengthBytes; i++ {
length <<= 8
length |= int64(buf[i])
}
contents = &spanReader{r, length}
return
}
// New format packet
tag = packetType(buf[0] & 0x3f)
length, isPartial, err := readLength(r)
if err != nil {
return
}
if isPartial {
contents = &partialLengthReader{
remaining: length,
isPartial: true,
r: r,
}
length = -1
} else {
contents = &spanReader{r, length}
}
return
}
// serializeHeader writes an OpenPGP packet header to w. See RFC 4880, section
// 4.2.
func serializeHeader(w io.Writer, ptype packetType, length int) (err error) {
var buf [6]byte
var n int
buf[0] = 0x80 | 0x40 | byte(ptype)
if length < 192 {
buf[1] = byte(length)
n = 2
} else if length < 8384 {
length -= 192
buf[1] = 192 + byte(length>>8)
buf[2] = byte(length)
n = 3
} else {
buf[1] = 255
buf[2] = byte(length >> 24)
buf[3] = byte(length >> 16)
buf[4] = byte(length >> 8)
buf[5] = byte(length)
n = 6
}
_, err = w.Write(buf[:n])
return
}
// serializeStreamHeader writes an OpenPGP packet header to w where the
// length of the packet is unknown. It returns a io.WriteCloser which can be
// used to write the contents of the packet. See RFC 4880, section 4.2.
func serializeStreamHeader(w io.WriteCloser, ptype packetType) (out io.WriteCloser, err error) {
var buf [1]byte
buf[0] = 0x80 | 0x40 | byte(ptype)
_, err = w.Write(buf[:])
if err != nil {
return
}
out = &partialLengthWriter{w: w}
return
}
// Packet represents an OpenPGP packet. Users are expected to try casting
// instances of this interface to specific packet types.
type Packet interface {
parse(io.Reader) error
}
// consumeAll reads from the given Reader until error, returning the number of
// bytes read.
func consumeAll(r io.Reader) (n int64, err error) {
var m int
var buf [1024]byte
for {
m, err = r.Read(buf[:])
n += int64(m)
if err == io.EOF {
err = nil
return
}
if err != nil {
return
}
}
panic("unreachable")
}
// packetType represents the numeric ids of the different OpenPGP packet types. See
// http://www.iana.org/assignments/pgp-parameters/pgp-parameters.xhtml#pgp-parameters-2
type packetType uint8
const (
packetTypeEncryptedKey packetType = 1
packetTypeSignature packetType = 2
packetTypeSymmetricKeyEncrypted packetType = 3
packetTypeOnePassSignature packetType = 4
packetTypePrivateKey packetType = 5
packetTypePublicKey packetType = 6
packetTypePrivateSubkey packetType = 7
packetTypeCompressed packetType = 8
packetTypeSymmetricallyEncrypted packetType = 9
packetTypeLiteralData packetType = 11
packetTypeUserId packetType = 13
packetTypePublicSubkey packetType = 14
packetTypeUserAttribute packetType = 17
packetTypeSymmetricallyEncryptedMDC packetType = 18
)
// peekVersion detects the version of a public key packet about to
// be read. A bufio.Reader at the original position of the io.Reader
// is returned.
func peekVersion(r io.Reader) (bufr *bufio.Reader, ver byte, err error) {
bufr = bufio.NewReader(r)
var verBuf []byte
if verBuf, err = bufr.Peek(1); err != nil {
return
}
ver = verBuf[0]
return
}
// Read reads a single OpenPGP packet from the given io.Reader. If there is an
// error parsing a packet, the whole packet is consumed from the input.
func Read(r io.Reader) (p Packet, err error) {
tag, _, contents, err := readHeader(r)
if err != nil {
return
}
switch tag {
case packetTypeEncryptedKey:
p = new(EncryptedKey)
case packetTypeSignature:
var version byte
// Detect signature version
if contents, version, err = peekVersion(contents); err != nil {
return
}
if version < 4 {
p = new(SignatureV3)
} else {
p = new(Signature)
}
case packetTypeSymmetricKeyEncrypted:
p = new(SymmetricKeyEncrypted)
case packetTypeOnePassSignature:
p = new(OnePassSignature)
case packetTypePrivateKey, packetTypePrivateSubkey:
pk := new(PrivateKey)
if tag == packetTypePrivateSubkey {
pk.IsSubkey = true
}
p = pk
case packetTypePublicKey, packetTypePublicSubkey:
var version byte
if contents, version, err = peekVersion(contents); err != nil {
return
}
isSubkey := tag == packetTypePublicSubkey
if version < 4 {
p = &PublicKeyV3{IsSubkey: isSubkey}
} else {
p = &PublicKey{IsSubkey: isSubkey}
}
case packetTypeCompressed:
p = new(Compressed)
case packetTypeSymmetricallyEncrypted:
p = new(SymmetricallyEncrypted)
case packetTypeLiteralData:
p = new(LiteralData)
case packetTypeUserId:
p = new(UserId)
case packetTypeUserAttribute:
p = new(UserAttribute)
case packetTypeSymmetricallyEncryptedMDC:
se := new(SymmetricallyEncrypted)
se.MDC = true
p = se
default:
err = errors.UnknownPacketTypeError(tag)
}
if p != nil {
err = p.parse(contents)
}
if err != nil {
consumeAll(contents)
}
return
}
// SignatureType represents the different semantic meanings of an OpenPGP
// signature. See RFC 4880, section 5.2.1.
type SignatureType uint8
const (
SigTypeBinary SignatureType = 0
SigTypeText = 1
SigTypeGenericCert = 0x10
SigTypePersonaCert = 0x11
SigTypeCasualCert = 0x12
SigTypePositiveCert = 0x13
SigTypeSubkeyBinding = 0x18
SigTypePrimaryKeyBinding = 0x19
SigTypeDirectSignature = 0x1F
SigTypeKeyRevocation = 0x20
SigTypeSubkeyRevocation = 0x28
SigTypeIdentityRevocation = 0x30
)
// PublicKeyAlgorithm represents the different public key system specified for
// OpenPGP. See
// http://www.iana.org/assignments/pgp-parameters/pgp-parameters.xhtml#pgp-parameters-12
type PublicKeyAlgorithm uint8
const (
PubKeyAlgoRSA PublicKeyAlgorithm = 1
PubKeyAlgoRSAEncryptOnly PublicKeyAlgorithm = 2
PubKeyAlgoRSASignOnly PublicKeyAlgorithm = 3
PubKeyAlgoElGamal PublicKeyAlgorithm = 16
PubKeyAlgoDSA PublicKeyAlgorithm = 17
// RFC 6637, Section 5.
PubKeyAlgoECDH PublicKeyAlgorithm = 18
PubKeyAlgoECDSA PublicKeyAlgorithm = 19
// RFC -1
PubKeyAlgoEdDSA PublicKeyAlgorithm = 22
)
// CanEncrypt returns true if it's possible to encrypt a message to a public
// key of the given type.
func (pka PublicKeyAlgorithm) CanEncrypt() bool {
switch pka {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoElGamal, PubKeyAlgoECDH:
return true
}
return false
}
// CanSign returns true if it's possible for a public key of the given type to
// sign a message.
func (pka PublicKeyAlgorithm) CanSign() bool {
switch pka {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly, PubKeyAlgoDSA, PubKeyAlgoECDSA, PubKeyAlgoEdDSA:
return true
}
return false
}
// CipherFunction represents the different block ciphers specified for OpenPGP. See
// http://www.iana.org/assignments/pgp-parameters/pgp-parameters.xhtml#pgp-parameters-13
type CipherFunction uint8
const (
Cipher3DES CipherFunction = 2
CipherCAST5 CipherFunction = 3
CipherAES128 CipherFunction = 7
CipherAES192 CipherFunction = 8
CipherAES256 CipherFunction = 9
)
// KeySize returns the key size, in bytes, of cipher.
func (cipher CipherFunction) KeySize() int {
switch cipher {
case Cipher3DES:
return 24
case CipherCAST5:
return cast5.KeySize
case CipherAES128:
return 16
case CipherAES192:
return 24
case CipherAES256:
return 32
}
return 0
}
// blockSize returns the block size, in bytes, of cipher.
func (cipher CipherFunction) blockSize() int {
switch cipher {
case Cipher3DES:
return des.BlockSize
case CipherCAST5:
return 8
case CipherAES128, CipherAES192, CipherAES256:
return 16
}
return 0
}
// new returns a fresh instance of the given cipher.
func (cipher CipherFunction) new(key []byte) (block cipher.Block) {
switch cipher {
case Cipher3DES:
block, _ = des.NewTripleDESCipher(key)
case CipherCAST5:
block, _ = cast5.NewCipher(key)
case CipherAES128, CipherAES192, CipherAES256:
block, _ = aes.NewCipher(key)
}
return
}
// readMPI reads a big integer from r. The bit length returned is the bit
// length that was specified in r. This is preserved so that the integer can be
// reserialized exactly.
func readMPI(r io.Reader) (mpi []byte, bitLength uint16, err error) {
var buf [2]byte
_, err = readFull(r, buf[0:])
if err != nil {
return
}
bitLength = uint16(buf[0])<<8 | uint16(buf[1])
numBytes := (int(bitLength) + 7) / 8
mpi = make([]byte, numBytes)
_, err = readFull(r, mpi)
return
}
// mpiLength returns the length of the given *big.Int when serialized as an
// MPI.
func mpiLength(n *big.Int) (mpiLengthInBytes int) {
mpiLengthInBytes = 2 /* MPI length */
mpiLengthInBytes += (n.BitLen() + 7) / 8
return
}
// writeMPI serializes a big integer to w.
func writeMPI(w io.Writer, bitLength uint16, mpiBytes []byte) (err error) {
_, err = w.Write([]byte{byte(bitLength >> 8), byte(bitLength)})
if err == nil {
_, err = w.Write(mpiBytes)
}
return
}
func WritePaddedBigInt(w io.Writer, length int, X *big.Int) (n int, err error) {
bytes := X.Bytes()
n1, err := w.Write(make([]byte, length-len(bytes)))
if err != nil {
return n1, err
}
n2, err := w.Write(bytes)
if err != nil {
return n2, err
}
return (n1 + n2), err
}
// Minimum number of bytes to fit the curve coordinates. All
// coordinates have to be 0-padded to this length.
func mpiPointByteLength(curve elliptic.Curve) int {
return (curve.Params().P.BitLen() + 7) / 8
}
// writeBig serializes a *big.Int to w.
func writeBig(w io.Writer, i *big.Int) error {
return writeMPI(w, uint16(i.BitLen()), i.Bytes())
}
// CompressionAlgo Represents the different compression algorithms
// supported by OpenPGP (except for BZIP2, which is not currently
// supported). See Section 9.3 of RFC 4880.
type CompressionAlgo uint8
const (
CompressionNone CompressionAlgo = 0
CompressionZIP CompressionAlgo = 1
CompressionZLIB CompressionAlgo = 2
)

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"crypto/cipher"
"crypto/dsa"
"crypto/ecdsa"
"crypto/sha1"
"fmt"
"io"
"io/ioutil"
"math/big"
"strconv"
"time"
"github.com/keybase/go-crypto/ed25519"
"github.com/keybase/go-crypto/openpgp/ecdh"
"github.com/keybase/go-crypto/openpgp/elgamal"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/s2k"
"github.com/keybase/go-crypto/rsa"
)
// PrivateKey represents a possibly encrypted private key. See RFC 4880,
// section 5.5.3.
type PrivateKey struct {
PublicKey
Encrypted bool // if true then the private key is unavailable until Decrypt has been called.
encryptedData []byte
cipher CipherFunction
s2k func(out, in []byte)
PrivateKey interface{} // An *rsa.PrivateKey or *dsa.PrivateKey.
sha1Checksum bool
iv []byte
s2kHeader []byte
}
type EdDSAPrivateKey struct {
PrivateKey
seed parsedMPI
}
func (e *EdDSAPrivateKey) Sign(digest []byte) (R, S []byte, err error) {
r := bytes.NewReader(e.seed.bytes)
publicKey, privateKey, err := ed25519.GenerateKey(r)
if err != nil {
return nil, nil, err
}
if !bytes.Equal(publicKey, e.PublicKey.edk.p.bytes[1:]) { // [1:] because [0] is 0x40 mpi header
return nil, nil, errors.UnsupportedError("EdDSA: Private key does not match public key.")
}
sig := ed25519.Sign(privateKey, digest)
sigLen := ed25519.SignatureSize / 2
return sig[:sigLen], sig[sigLen:], nil
}
func NewRSAPrivateKey(currentTime time.Time, priv *rsa.PrivateKey) *PrivateKey {
pk := new(PrivateKey)
pk.PublicKey = *NewRSAPublicKey(currentTime, &priv.PublicKey)
pk.PrivateKey = priv
return pk
}
func NewDSAPrivateKey(currentTime time.Time, priv *dsa.PrivateKey) *PrivateKey {
pk := new(PrivateKey)
pk.PublicKey = *NewDSAPublicKey(currentTime, &priv.PublicKey)
pk.PrivateKey = priv
return pk
}
func NewElGamalPrivateKey(currentTime time.Time, priv *elgamal.PrivateKey) *PrivateKey {
pk := new(PrivateKey)
pk.PublicKey = *NewElGamalPublicKey(currentTime, &priv.PublicKey)
pk.PrivateKey = priv
return pk
}
func NewECDSAPrivateKey(currentTime time.Time, priv *ecdsa.PrivateKey) *PrivateKey {
pk := new(PrivateKey)
pk.PublicKey = *NewECDSAPublicKey(currentTime, &priv.PublicKey)
pk.PrivateKey = priv
return pk
}
func (pk *PrivateKey) parse(r io.Reader) (err error) {
err = (&pk.PublicKey).parse(r)
if err != nil {
return
}
var buf [1]byte
_, err = readFull(r, buf[:])
if err != nil {
return
}
s2kType := buf[0]
switch s2kType {
case 0:
pk.s2k = nil
pk.Encrypted = false
case 254, 255:
_, err = readFull(r, buf[:])
if err != nil {
return
}
pk.cipher = CipherFunction(buf[0])
pk.Encrypted = true
pk.s2k, err = s2k.Parse(r)
if err != nil {
return
}
if s2kType == 254 {
pk.sha1Checksum = true
}
// S2K == nil implies that we got a "GNU Dummy" S2K. For instance,
// because our master secret key is on a USB key in a vault somewhere.
// In that case, there is no further data to consume here.
if pk.s2k == nil {
pk.Encrypted = false
return
}
default:
return errors.UnsupportedError("deprecated s2k function in private key")
}
if pk.Encrypted {
blockSize := pk.cipher.blockSize()
if blockSize == 0 {
return errors.UnsupportedError("unsupported cipher in private key: " + strconv.Itoa(int(pk.cipher)))
}
pk.iv = make([]byte, blockSize)
_, err = readFull(r, pk.iv)
if err != nil {
return
}
}
pk.encryptedData, err = ioutil.ReadAll(r)
if err != nil {
return
}
if !pk.Encrypted {
return pk.parsePrivateKey(pk.encryptedData)
}
return
}
func mod64kHash(d []byte) uint16 {
var h uint16
for _, b := range d {
h += uint16(b)
}
return h
}
// Encrypt is the counterpart to the Decrypt() method below. It encrypts
// the private key with the provided passphrase. If config is nil, then
// the standard, and sensible, defaults apply.
//
// A key will be derived from the given passphrase using S2K Specifier
// Type 3 (Iterated + Salted, see RFC-4880 Sec. 3.7.1.3). This choice
// is hardcoded in s2k.Serialize(). S2KCount is hardcoded to 0, which is
// equivalent to 65536. And the hash algorithm for key-derivation can be
// set with config. The encrypted PrivateKey, using the algorithm specified
// in config (if provided), is written out to the encryptedData member.
// When Serialize() is called, this encryptedData member will be
// serialized, using S2K Usage value of 254, and thus SHA1 checksum.
func (pk *PrivateKey) Encrypt(passphrase []byte, config *Config) (err error) {
if pk.PrivateKey == nil {
return errors.InvalidArgumentError("there is no private key to encrypt")
}
pk.sha1Checksum = true
pk.cipher = config.Cipher()
s2kConfig := s2k.Config{
Hash: config.Hash(),
S2KCount: 0,
}
s2kBuf := bytes.NewBuffer(nil)
derivedKey := make([]byte, pk.cipher.KeySize())
err = s2k.Serialize(s2kBuf, derivedKey, config.Random(), passphrase, &s2kConfig)
if err != nil {
return err
}
pk.s2kHeader = s2kBuf.Bytes()
// No good way to set pk.s2k but to call s2k.Parse(),
// even though we have all the information here, but
// most of the functions needed are private to s2k.
pk.s2k, err = s2k.Parse(s2kBuf)
pk.iv = make([]byte, pk.cipher.blockSize())
if _, err = config.Random().Read(pk.iv); err != nil {
return err
}
privateKeyBuf := bytes.NewBuffer(nil)
if err = pk.serializePrivateKey(privateKeyBuf); err != nil {
return err
}
checksum := sha1.Sum(privateKeyBuf.Bytes())
if _, err = privateKeyBuf.Write(checksum[:]); err != nil {
return err
}
pkData := privateKeyBuf.Bytes()
block := pk.cipher.new(derivedKey)
pk.encryptedData = make([]byte, len(pkData))
cfb := cipher.NewCFBEncrypter(block, pk.iv)
cfb.XORKeyStream(pk.encryptedData, pkData)
pk.Encrypted = true
return nil
}
func (pk *PrivateKey) Serialize(w io.Writer) (err error) {
buf := bytes.NewBuffer(nil)
err = pk.PublicKey.serializeWithoutHeaders(buf)
if err != nil {
return
}
privateKeyBuf := bytes.NewBuffer(nil)
if pk.PrivateKey == nil {
_, err = buf.Write([]byte{
254, // SHA-1 Convention
9, // Encryption scheme (AES256)
101, // GNU Extensions
2, // Hash value (SHA1)
'G', 'N', 'U', // "GNU" as a string
1, // Extension type 1001 (minus 1000)
})
} else if pk.Encrypted {
_, err = buf.Write([]byte{
254, // SHA-1 Convention
byte(pk.cipher), // Encryption scheme
})
if err != nil {
return err
}
if _, err = buf.Write(pk.s2kHeader); err != nil {
return err
}
if _, err = buf.Write(pk.iv); err != nil {
return err
}
if _, err = privateKeyBuf.Write(pk.encryptedData); err != nil {
return err
}
} else {
buf.WriteByte(0 /* no encryption */)
if err = pk.serializePrivateKey(privateKeyBuf); err != nil {
return err
}
}
ptype := packetTypePrivateKey
contents := buf.Bytes()
privateKeyBytes := privateKeyBuf.Bytes()
if pk.IsSubkey {
ptype = packetTypePrivateSubkey
}
totalLen := len(contents) + len(privateKeyBytes)
if !pk.Encrypted {
totalLen += 2
}
err = serializeHeader(w, ptype, totalLen)
if err != nil {
return
}
_, err = w.Write(contents)
if err != nil {
return
}
_, err = w.Write(privateKeyBytes)
if err != nil {
return
}
if len(privateKeyBytes) > 0 && !pk.Encrypted {
checksum := mod64kHash(privateKeyBytes)
var checksumBytes [2]byte
checksumBytes[0] = byte(checksum >> 8)
checksumBytes[1] = byte(checksum)
_, err = w.Write(checksumBytes[:])
}
return
}
func (pk *PrivateKey) serializePrivateKey(w io.Writer) (err error) {
switch priv := pk.PrivateKey.(type) {
case *rsa.PrivateKey:
err = serializeRSAPrivateKey(w, priv)
case *dsa.PrivateKey:
err = serializeDSAPrivateKey(w, priv)
case *elgamal.PrivateKey:
err = serializeElGamalPrivateKey(w, priv)
case *ecdsa.PrivateKey:
err = serializeECDSAPrivateKey(w, priv)
case *ecdh.PrivateKey:
err = serializeECDHPrivateKey(w, priv)
case *EdDSAPrivateKey:
err = serializeEdDSAPrivateKey(w, priv)
default:
err = errors.InvalidArgumentError("unknown private key type")
}
return err
}
func serializeRSAPrivateKey(w io.Writer, priv *rsa.PrivateKey) error {
err := writeBig(w, priv.D)
if err != nil {
return err
}
err = writeBig(w, priv.Primes[1])
if err != nil {
return err
}
err = writeBig(w, priv.Primes[0])
if err != nil {
return err
}
return writeBig(w, priv.Precomputed.Qinv)
}
func serializeDSAPrivateKey(w io.Writer, priv *dsa.PrivateKey) error {
return writeBig(w, priv.X)
}
func serializeElGamalPrivateKey(w io.Writer, priv *elgamal.PrivateKey) error {
return writeBig(w, priv.X)
}
func serializeECDSAPrivateKey(w io.Writer, priv *ecdsa.PrivateKey) error {
return writeBig(w, priv.D)
}
func serializeECDHPrivateKey(w io.Writer, priv *ecdh.PrivateKey) error {
return writeBig(w, priv.X)
}
func serializeEdDSAPrivateKey(w io.Writer, priv *EdDSAPrivateKey) error {
return writeMPI(w, priv.seed.bitLength, priv.seed.bytes)
}
// Decrypt decrypts an encrypted private key using a passphrase.
func (pk *PrivateKey) Decrypt(passphrase []byte) error {
if !pk.Encrypted {
return nil
}
// For GNU Dummy S2K, there's no key here, so don't do anything.
if pk.s2k == nil {
return nil
}
key := make([]byte, pk.cipher.KeySize())
pk.s2k(key, passphrase)
block := pk.cipher.new(key)
cfb := cipher.NewCFBDecrypter(block, pk.iv)
data := make([]byte, len(pk.encryptedData))
cfb.XORKeyStream(data, pk.encryptedData)
if pk.sha1Checksum {
if len(data) < sha1.Size {
return errors.StructuralError("truncated private key data")
}
h := sha1.New()
h.Write(data[:len(data)-sha1.Size])
sum := h.Sum(nil)
if !bytes.Equal(sum, data[len(data)-sha1.Size:]) {
return errors.StructuralError("private key checksum failure")
}
data = data[:len(data)-sha1.Size]
} else {
if len(data) < 2 {
return errors.StructuralError("truncated private key data")
}
var sum uint16
for i := 0; i < len(data)-2; i++ {
sum += uint16(data[i])
}
if data[len(data)-2] != uint8(sum>>8) ||
data[len(data)-1] != uint8(sum) {
return errors.StructuralError("private key checksum failure")
}
data = data[:len(data)-2]
}
return pk.parsePrivateKey(data)
}
func (pk *PrivateKey) parsePrivateKey(data []byte) (err error) {
switch pk.PublicKey.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly, PubKeyAlgoRSAEncryptOnly:
return pk.parseRSAPrivateKey(data)
case PubKeyAlgoDSA:
return pk.parseDSAPrivateKey(data)
case PubKeyAlgoElGamal:
return pk.parseElGamalPrivateKey(data)
case PubKeyAlgoECDSA:
return pk.parseECDSAPrivateKey(data)
case PubKeyAlgoECDH:
return pk.parseECDHPrivateKey(data)
case PubKeyAlgoEdDSA:
return pk.parseEdDSAPrivateKey(data)
}
panic("impossible")
}
func (pk *PrivateKey) parseRSAPrivateKey(data []byte) (err error) {
rsaPub := pk.PublicKey.PublicKey.(*rsa.PublicKey)
rsaPriv := new(rsa.PrivateKey)
rsaPriv.PublicKey = *rsaPub
buf := bytes.NewBuffer(data)
d, _, err := readMPI(buf)
if err != nil {
return
}
p, _, err := readMPI(buf)
if err != nil {
return
}
q, _, err := readMPI(buf)
if err != nil {
return
}
rsaPriv.D = new(big.Int).SetBytes(d)
rsaPriv.Primes = make([]*big.Int, 2)
rsaPriv.Primes[0] = new(big.Int).SetBytes(p)
rsaPriv.Primes[1] = new(big.Int).SetBytes(q)
if err := rsaPriv.Validate(); err != nil {
return err
}
rsaPriv.Precompute()
pk.PrivateKey = rsaPriv
pk.Encrypted = false
pk.encryptedData = nil
return nil
}
func (pk *PrivateKey) parseDSAPrivateKey(data []byte) (err error) {
dsaPub := pk.PublicKey.PublicKey.(*dsa.PublicKey)
dsaPriv := new(dsa.PrivateKey)
dsaPriv.PublicKey = *dsaPub
buf := bytes.NewBuffer(data)
x, _, err := readMPI(buf)
if err != nil {
return
}
dsaPriv.X = new(big.Int).SetBytes(x)
pk.PrivateKey = dsaPriv
pk.Encrypted = false
pk.encryptedData = nil
return nil
}
func (pk *PrivateKey) parseElGamalPrivateKey(data []byte) (err error) {
pub := pk.PublicKey.PublicKey.(*elgamal.PublicKey)
priv := new(elgamal.PrivateKey)
priv.PublicKey = *pub
buf := bytes.NewBuffer(data)
x, _, err := readMPI(buf)
if err != nil {
return
}
priv.X = new(big.Int).SetBytes(x)
pk.PrivateKey = priv
pk.Encrypted = false
pk.encryptedData = nil
return nil
}
func (pk *PrivateKey) parseECDHPrivateKey(data []byte) (err error) {
pub := pk.PublicKey.PublicKey.(*ecdh.PublicKey)
priv := new(ecdh.PrivateKey)
priv.PublicKey = *pub
buf := bytes.NewBuffer(data)
d, _, err := readMPI(buf)
if err != nil {
return
}
priv.X = new(big.Int).SetBytes(d)
pk.PrivateKey = priv
pk.Encrypted = false
pk.encryptedData = nil
return nil
}
func (pk *PrivateKey) parseECDSAPrivateKey(data []byte) (err error) {
ecdsaPub := pk.PublicKey.PublicKey.(*ecdsa.PublicKey)
ecdsaPriv := new(ecdsa.PrivateKey)
ecdsaPriv.PublicKey = *ecdsaPub
buf := bytes.NewBuffer(data)
d, _, err := readMPI(buf)
if err != nil {
return
}
ecdsaPriv.D = new(big.Int).SetBytes(d)
pk.PrivateKey = ecdsaPriv
pk.Encrypted = false
pk.encryptedData = nil
return nil
}
func (pk *PrivateKey) parseEdDSAPrivateKey(data []byte) (err error) {
eddsaPriv := new(EdDSAPrivateKey)
eddsaPriv.PublicKey = pk.PublicKey
buf := bytes.NewBuffer(data)
eddsaPriv.seed.bytes, eddsaPriv.seed.bitLength, err = readMPI(buf)
if err != nil {
return err
}
if bLen := len(eddsaPriv.seed.bytes); bLen != 32 { // 32 bytes private part of ed25519 key.
return errors.UnsupportedError(fmt.Sprintf("Unexpected EdDSA private key length: %d", bLen))
}
pk.PrivateKey = eddsaPriv
pk.Encrypted = false
pk.encryptedData = nil
return nil
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"crypto"
"crypto/dsa"
"crypto/ecdsa"
"crypto/elliptic"
"crypto/sha1"
_ "crypto/sha256"
_ "crypto/sha512"
"encoding/binary"
"fmt"
"hash"
"io"
"math/big"
"strconv"
"time"
"github.com/keybase/go-crypto/brainpool"
"github.com/keybase/go-crypto/curve25519"
"github.com/keybase/go-crypto/ed25519"
"github.com/keybase/go-crypto/openpgp/ecdh"
"github.com/keybase/go-crypto/openpgp/elgamal"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/rsa"
)
var (
// NIST curve P-256
oidCurveP256 []byte = []byte{0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x03, 0x01, 0x07}
// NIST curve P-384
oidCurveP384 []byte = []byte{0x2B, 0x81, 0x04, 0x00, 0x22}
// NIST curve P-521
oidCurveP521 []byte = []byte{0x2B, 0x81, 0x04, 0x00, 0x23}
// Brainpool curve P-256r1
oidCurveP256r1 []byte = []byte{0x2B, 0x24, 0x03, 0x03, 0x02, 0x08, 0x01, 0x01, 0x07}
// Brainpool curve P-384r1
oidCurveP384r1 []byte = []byte{0x2B, 0x24, 0x03, 0x03, 0x02, 0x08, 0x01, 0x01, 0x0B}
// Brainpool curve P-512r1
oidCurveP512r1 []byte = []byte{0x2B, 0x24, 0x03, 0x03, 0x02, 0x08, 0x01, 0x01, 0x0D}
// EdDSA
oidEdDSA []byte = []byte{0x2B, 0x06, 0x01, 0x04, 0x01, 0xDA, 0x47, 0x0F, 0x01}
// cv25519
oidCurve25519 []byte = []byte{0x2B, 0x06, 0x01, 0x04, 0x01, 0x97, 0x55, 0x01, 0x05, 0x01}
)
const maxOIDLength = 10
// ecdsaKey stores the algorithm-specific fields for ECDSA keys.
// as defined in RFC 6637, Section 9.
type ecdsaKey struct {
// oid contains the OID byte sequence identifying the elliptic curve used
oid []byte
// p contains the elliptic curve point that represents the public key
p parsedMPI
}
type edDSAkey struct {
ecdsaKey
}
func copyFrontFill(dst, src []byte, length int) int {
if srcLen := len(src); srcLen < length {
return copy(dst[length-srcLen:], src[:])
} else {
return copy(dst[:], src[:])
}
}
func (e *edDSAkey) Verify(payload []byte, r parsedMPI, s parsedMPI) bool {
const halfSigSize = ed25519.SignatureSize / 2
var sig [ed25519.SignatureSize]byte
// NOTE: The first byte is 0x40 - MPI header
// TODO: Maybe clean the code up and use 0x40 as a header when
// reading and keep only actual number in p field. Find out how
// other MPIs are stored.
key := e.p.bytes[1:]
// Note: it may happen that R + S do not form 64-byte signature buffer that
// ed25519 expects, but because we copy it over to an array of exact size,
// we will always pass correctly sized slice to Verify. Slice too short
// would make ed25519 panic().
copyFrontFill(sig[:halfSigSize], r.bytes, halfSigSize)
copyFrontFill(sig[halfSigSize:], s.bytes, halfSigSize)
return ed25519.Verify(key, payload, sig[:])
}
// parseOID reads the OID for the curve as defined in RFC 6637, Section 9.
func parseOID(r io.Reader) (oid []byte, err error) {
buf := make([]byte, maxOIDLength)
if _, err = readFull(r, buf[:1]); err != nil {
return
}
oidLen := buf[0]
if int(oidLen) > len(buf) {
err = errors.UnsupportedError("invalid oid length: " + strconv.Itoa(int(oidLen)))
return
}
oid = buf[:oidLen]
_, err = readFull(r, oid)
return
}
func (f *ecdsaKey) parse(r io.Reader) (err error) {
if f.oid, err = parseOID(r); err != nil {
return err
}
f.p.bytes, f.p.bitLength, err = readMPI(r)
return err
}
func (f *ecdsaKey) serialize(w io.Writer) (err error) {
buf := make([]byte, maxOIDLength+1)
buf[0] = byte(len(f.oid))
copy(buf[1:], f.oid)
if _, err = w.Write(buf[:len(f.oid)+1]); err != nil {
return
}
return writeMPIs(w, f.p)
}
func getCurveByOid(oid []byte) elliptic.Curve {
switch {
case bytes.Equal(oid, oidCurveP256):
return elliptic.P256()
case bytes.Equal(oid, oidCurveP384):
return elliptic.P384()
case bytes.Equal(oid, oidCurveP521):
return elliptic.P521()
case bytes.Equal(oid, oidCurveP256r1):
return brainpool.P256r1()
case bytes.Equal(oid, oidCurveP384r1):
return brainpool.P384r1()
case bytes.Equal(oid, oidCurveP512r1):
return brainpool.P512r1()
case bytes.Equal(oid, oidCurve25519):
return curve25519.Cv25519()
default:
return nil
}
}
func (f *ecdsaKey) newECDSA() (*ecdsa.PublicKey, error) {
var c = getCurveByOid(f.oid)
// Curve25519 should not be used in ECDSA.
if c == nil || bytes.Equal(f.oid, oidCurve25519) {
return nil, errors.UnsupportedError(fmt.Sprintf("unsupported oid: %x", f.oid))
}
// Note: Unmarshal already checks if point is on curve.
x, y := elliptic.Unmarshal(c, f.p.bytes)
if x == nil {
return nil, errors.UnsupportedError("failed to parse EC point")
}
return &ecdsa.PublicKey{Curve: c, X: x, Y: y}, nil
}
func (f *ecdsaKey) newECDH() (*ecdh.PublicKey, error) {
var c = getCurveByOid(f.oid)
if c == nil {
return nil, errors.UnsupportedError(fmt.Sprintf("unsupported oid: %x", f.oid))
}
// ecdh.Unmarshal handles unmarshaling for all curve types. It
// also checks if point is on curve.
x, y := ecdh.Unmarshal(c, f.p.bytes)
if x == nil {
return nil, errors.UnsupportedError("failed to parse EC point")
}
return &ecdh.PublicKey{Curve: c, X: x, Y: y}, nil
}
func (f *ecdsaKey) byteLen() int {
return 1 + len(f.oid) + 2 + len(f.p.bytes)
}
type kdfHashFunction byte
type kdfAlgorithm byte
// ecdhKdf stores key derivation function parameters
// used for ECDH encryption. See RFC 6637, Section 9.
type ecdhKdf struct {
KdfHash kdfHashFunction
KdfAlgo kdfAlgorithm
}
func (f *ecdhKdf) parse(r io.Reader) (err error) {
buf := make([]byte, 1)
if _, err = readFull(r, buf); err != nil {
return
}
kdfLen := int(buf[0])
if kdfLen < 3 {
return errors.UnsupportedError("Unsupported ECDH KDF length: " + strconv.Itoa(kdfLen))
}
buf = make([]byte, kdfLen)
if _, err = readFull(r, buf); err != nil {
return
}
reserved := int(buf[0])
f.KdfHash = kdfHashFunction(buf[1])
f.KdfAlgo = kdfAlgorithm(buf[2])
if reserved != 0x01 {
return errors.UnsupportedError("Unsupported KDF reserved field: " + strconv.Itoa(reserved))
}
return
}
func (f *ecdhKdf) serialize(w io.Writer) (err error) {
buf := make([]byte, 4)
// See RFC 6637, Section 9, Algorithm-Specific Fields for ECDH keys.
buf[0] = byte(0x03) // Length of the following fields
buf[1] = byte(0x01) // Reserved for future extensions, must be 1 for now
buf[2] = byte(f.KdfHash)
buf[3] = byte(f.KdfAlgo)
_, err = w.Write(buf[:])
return
}
func (f *ecdhKdf) byteLen() int {
return 4
}
// PublicKey represents an OpenPGP public key. See RFC 4880, section 5.5.2.
type PublicKey struct {
CreationTime time.Time
PubKeyAlgo PublicKeyAlgorithm
PublicKey interface{} // *rsa.PublicKey, *dsa.PublicKey or *ecdsa.PublicKey
Fingerprint [20]byte
KeyId uint64
IsSubkey bool
n, e, p, q, g, y parsedMPI
// RFC 6637 fields
ec *ecdsaKey
ecdh *ecdhKdf
// EdDSA fields (no RFC available), uses ecdsa scaffolding
edk *edDSAkey
}
// signingKey provides a convenient abstraction over signature verification
// for v3 and v4 public keys.
type signingKey interface {
SerializeSignaturePrefix(io.Writer)
serializeWithoutHeaders(io.Writer) error
}
func FromBig(n *big.Int) parsedMPI {
return parsedMPI{
bytes: n.Bytes(),
bitLength: uint16(n.BitLen()),
}
}
func FromBytes(bytes []byte) parsedMPI {
return parsedMPI{
bytes: bytes,
bitLength: uint16(8 * len(bytes)),
}
}
// NewRSAPublicKey returns a PublicKey that wraps the given rsa.PublicKey.
func NewRSAPublicKey(creationTime time.Time, pub *rsa.PublicKey) *PublicKey {
pk := &PublicKey{
CreationTime: creationTime,
PubKeyAlgo: PubKeyAlgoRSA,
PublicKey: pub,
n: FromBig(pub.N),
e: FromBig(big.NewInt(int64(pub.E))),
}
pk.setFingerPrintAndKeyId()
return pk
}
// NewDSAPublicKey returns a PublicKey that wraps the given dsa.PublicKey.
func NewDSAPublicKey(creationTime time.Time, pub *dsa.PublicKey) *PublicKey {
pk := &PublicKey{
CreationTime: creationTime,
PubKeyAlgo: PubKeyAlgoDSA,
PublicKey: pub,
p: FromBig(pub.P),
q: FromBig(pub.Q),
g: FromBig(pub.G),
y: FromBig(pub.Y),
}
pk.setFingerPrintAndKeyId()
return pk
}
// check EdDSA public key material.
// There is currently no RFC for it, but it doesn't mean it's not
// implemented or in use.
func (e *edDSAkey) check() error {
if !bytes.Equal(e.oid, oidEdDSA) {
return errors.UnsupportedError(fmt.Sprintf("Bad OID for EdDSA key: %v", e.oid))
}
if bLen := len(e.p.bytes); bLen != 33 { // 32 bytes for ed25519 key and 1 byte for 0x40 header
return errors.UnsupportedError(fmt.Sprintf("Unexpected EdDSA public key length: %d", bLen))
}
return nil
}
// NewElGamalPublicKey returns a PublicKey that wraps the given elgamal.PublicKey.
func NewElGamalPublicKey(creationTime time.Time, pub *elgamal.PublicKey) *PublicKey {
pk := &PublicKey{
CreationTime: creationTime,
PubKeyAlgo: PubKeyAlgoElGamal,
PublicKey: pub,
p: FromBig(pub.P),
g: FromBig(pub.G),
y: FromBig(pub.Y),
}
pk.setFingerPrintAndKeyId()
return pk
}
func NewECDSAPublicKey(creationTime time.Time, pub *ecdsa.PublicKey) *PublicKey {
pk := &PublicKey{
CreationTime: creationTime,
PubKeyAlgo: PubKeyAlgoECDSA,
PublicKey: pub,
ec: new(ecdsaKey),
}
switch pub.Curve {
case elliptic.P256():
pk.ec.oid = oidCurveP256
case elliptic.P384():
pk.ec.oid = oidCurveP384
case elliptic.P521():
pk.ec.oid = oidCurveP521
case brainpool.P256r1():
pk.ec.oid = oidCurveP256r1
case brainpool.P384r1():
pk.ec.oid = oidCurveP384r1
case brainpool.P512r1():
pk.ec.oid = oidCurveP512r1
}
pk.ec.p.bytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y)
pk.ec.p.bitLength = uint16(8 * len(pk.ec.p.bytes))
pk.setFingerPrintAndKeyId()
return pk
}
func (pk *PublicKey) parse(r io.Reader) (err error) {
// RFC 4880, section 5.5.2
var buf [6]byte
_, err = readFull(r, buf[:])
if err != nil {
return
}
if buf[0] != 4 {
return errors.UnsupportedError("public key version")
}
pk.CreationTime = time.Unix(int64(uint32(buf[1])<<24|uint32(buf[2])<<16|uint32(buf[3])<<8|uint32(buf[4])), 0)
pk.PubKeyAlgo = PublicKeyAlgorithm(buf[5])
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
err = pk.parseRSA(r)
case PubKeyAlgoDSA:
err = pk.parseDSA(r)
case PubKeyAlgoElGamal:
err = pk.parseElGamal(r)
case PubKeyAlgoEdDSA:
pk.edk = new(edDSAkey)
if err = pk.edk.parse(r); err != nil {
return err
}
err = pk.edk.check()
case PubKeyAlgoECDSA:
pk.ec = new(ecdsaKey)
if err = pk.ec.parse(r); err != nil {
return err
}
pk.PublicKey, err = pk.ec.newECDSA()
case PubKeyAlgoECDH:
pk.ec = new(ecdsaKey)
if err = pk.ec.parse(r); err != nil {
return
}
pk.ecdh = new(ecdhKdf)
if err = pk.ecdh.parse(r); err != nil {
return
}
pk.PublicKey, err = pk.ec.newECDH()
default:
err = errors.UnsupportedError("public key type: " + strconv.Itoa(int(pk.PubKeyAlgo)))
}
if err != nil {
return
}
pk.setFingerPrintAndKeyId()
return
}
func (pk *PublicKey) setFingerPrintAndKeyId() {
// RFC 4880, section 12.2
fingerPrint := sha1.New()
pk.SerializeSignaturePrefix(fingerPrint)
pk.serializeWithoutHeaders(fingerPrint)
copy(pk.Fingerprint[:], fingerPrint.Sum(nil))
pk.KeyId = binary.BigEndian.Uint64(pk.Fingerprint[12:20])
}
// parseRSA parses RSA public key material from the given Reader. See RFC 4880,
// section 5.5.2.
func (pk *PublicKey) parseRSA(r io.Reader) (err error) {
pk.n.bytes, pk.n.bitLength, err = readMPI(r)
if err != nil {
return
}
pk.e.bytes, pk.e.bitLength, err = readMPI(r)
if err != nil {
return
}
if len(pk.e.bytes) > 7 {
err = errors.UnsupportedError("large public exponent")
return
}
rsa := &rsa.PublicKey{
N: new(big.Int).SetBytes(pk.n.bytes),
E: 0,
}
for i := 0; i < len(pk.e.bytes); i++ {
rsa.E <<= 8
rsa.E |= int64(pk.e.bytes[i])
}
pk.PublicKey = rsa
return
}
// parseDSA parses DSA public key material from the given Reader. See RFC 4880,
// section 5.5.2.
func (pk *PublicKey) parseDSA(r io.Reader) (err error) {
pk.p.bytes, pk.p.bitLength, err = readMPI(r)
if err != nil {
return
}
pk.q.bytes, pk.q.bitLength, err = readMPI(r)
if err != nil {
return
}
pk.g.bytes, pk.g.bitLength, err = readMPI(r)
if err != nil {
return
}
pk.y.bytes, pk.y.bitLength, err = readMPI(r)
if err != nil {
return
}
dsa := new(dsa.PublicKey)
dsa.P = new(big.Int).SetBytes(pk.p.bytes)
dsa.Q = new(big.Int).SetBytes(pk.q.bytes)
dsa.G = new(big.Int).SetBytes(pk.g.bytes)
dsa.Y = new(big.Int).SetBytes(pk.y.bytes)
pk.PublicKey = dsa
return
}
// parseElGamal parses ElGamal public key material from the given Reader. See
// RFC 4880, section 5.5.2.
func (pk *PublicKey) parseElGamal(r io.Reader) (err error) {
pk.p.bytes, pk.p.bitLength, err = readMPI(r)
if err != nil {
return
}
pk.g.bytes, pk.g.bitLength, err = readMPI(r)
if err != nil {
return
}
pk.y.bytes, pk.y.bitLength, err = readMPI(r)
if err != nil {
return
}
elgamal := new(elgamal.PublicKey)
elgamal.P = new(big.Int).SetBytes(pk.p.bytes)
elgamal.G = new(big.Int).SetBytes(pk.g.bytes)
elgamal.Y = new(big.Int).SetBytes(pk.y.bytes)
pk.PublicKey = elgamal
return
}
// SerializeSignaturePrefix writes the prefix for this public key to the given Writer.
// The prefix is used when calculating a signature over this public key. See
// RFC 4880, section 5.2.4.
func (pk *PublicKey) SerializeSignaturePrefix(h io.Writer) {
var pLength uint16
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
pLength += 2 + uint16(len(pk.n.bytes))
pLength += 2 + uint16(len(pk.e.bytes))
case PubKeyAlgoDSA:
pLength += 2 + uint16(len(pk.p.bytes))
pLength += 2 + uint16(len(pk.q.bytes))
pLength += 2 + uint16(len(pk.g.bytes))
pLength += 2 + uint16(len(pk.y.bytes))
case PubKeyAlgoElGamal:
pLength += 2 + uint16(len(pk.p.bytes))
pLength += 2 + uint16(len(pk.g.bytes))
pLength += 2 + uint16(len(pk.y.bytes))
case PubKeyAlgoECDSA:
pLength += uint16(pk.ec.byteLen())
case PubKeyAlgoECDH:
pLength += uint16(pk.ec.byteLen())
pLength += uint16(pk.ecdh.byteLen())
case PubKeyAlgoEdDSA:
pLength += uint16(pk.edk.byteLen())
default:
panic("unknown public key algorithm")
}
pLength += 6
h.Write([]byte{0x99, byte(pLength >> 8), byte(pLength)})
return
}
func (pk *PublicKey) Serialize(w io.Writer) (err error) {
length := 6 // 6 byte header
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
length += 2 + len(pk.n.bytes)
length += 2 + len(pk.e.bytes)
case PubKeyAlgoDSA:
length += 2 + len(pk.p.bytes)
length += 2 + len(pk.q.bytes)
length += 2 + len(pk.g.bytes)
length += 2 + len(pk.y.bytes)
case PubKeyAlgoElGamal:
length += 2 + len(pk.p.bytes)
length += 2 + len(pk.g.bytes)
length += 2 + len(pk.y.bytes)
case PubKeyAlgoECDSA:
length += pk.ec.byteLen()
case PubKeyAlgoECDH:
length += pk.ec.byteLen()
length += pk.ecdh.byteLen()
case PubKeyAlgoEdDSA:
length += pk.edk.byteLen()
default:
panic("unknown public key algorithm")
}
packetType := packetTypePublicKey
if pk.IsSubkey {
packetType = packetTypePublicSubkey
}
err = serializeHeader(w, packetType, length)
if err != nil {
return
}
return pk.serializeWithoutHeaders(w)
}
// serializeWithoutHeaders marshals the PublicKey to w in the form of an
// OpenPGP public key packet, not including the packet header.
func (pk *PublicKey) serializeWithoutHeaders(w io.Writer) (err error) {
var buf [6]byte
buf[0] = 4
t := uint32(pk.CreationTime.Unix())
buf[1] = byte(t >> 24)
buf[2] = byte(t >> 16)
buf[3] = byte(t >> 8)
buf[4] = byte(t)
buf[5] = byte(pk.PubKeyAlgo)
_, err = w.Write(buf[:])
if err != nil {
return
}
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
return writeMPIs(w, pk.n, pk.e)
case PubKeyAlgoDSA:
return writeMPIs(w, pk.p, pk.q, pk.g, pk.y)
case PubKeyAlgoElGamal:
return writeMPIs(w, pk.p, pk.g, pk.y)
case PubKeyAlgoECDSA:
return pk.ec.serialize(w)
case PubKeyAlgoEdDSA:
return pk.edk.serialize(w)
case PubKeyAlgoECDH:
if err = pk.ec.serialize(w); err != nil {
return
}
return pk.ecdh.serialize(w)
}
return errors.InvalidArgumentError("bad public-key algorithm")
}
// CanSign returns true iff this public key can generate signatures
func (pk *PublicKey) CanSign() bool {
return pk.PubKeyAlgo != PubKeyAlgoRSAEncryptOnly && pk.PubKeyAlgo != PubKeyAlgoElGamal
}
// VerifySignature returns nil iff sig is a valid signature, made by this
// public key, of the data hashed into signed. signed is mutated by this call.
func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err error) {
if !pk.CanSign() {
return errors.InvalidArgumentError("public key cannot generate signatures")
}
signed.Write(sig.HashSuffix)
hashBytes := signed.Sum(nil)
// NOTE(maxtaco) 2016-08-22
//
// We used to do this:
//
// if hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1] {
// return errors.SignatureError("hash tag doesn't match")
// }
//
// But don't do anything in this case. Some GPGs generate bad
// 2-byte hash prefixes, but GPG also doesn't seem to care on
// import. See BrentMaxwell's key. I think it's safe to disable
// this check!
if pk.PubKeyAlgo != sig.PubKeyAlgo {
return errors.InvalidArgumentError("public key and signature use different algorithms")
}
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
rsaPublicKey, _ := pk.PublicKey.(*rsa.PublicKey)
err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes)
if err != nil {
return errors.SignatureError("RSA verification failure")
}
return nil
case PubKeyAlgoDSA:
dsaPublicKey, _ := pk.PublicKey.(*dsa.PublicKey)
// Need to truncate hashBytes to match FIPS 186-3 section 4.6.
subgroupSize := (dsaPublicKey.Q.BitLen() + 7) / 8
if len(hashBytes) > subgroupSize {
hashBytes = hashBytes[:subgroupSize]
}
if !dsa.Verify(dsaPublicKey, hashBytes, new(big.Int).SetBytes(sig.DSASigR.bytes), new(big.Int).SetBytes(sig.DSASigS.bytes)) {
return errors.SignatureError("DSA verification failure")
}
return nil
case PubKeyAlgoECDSA:
ecdsaPublicKey := pk.PublicKey.(*ecdsa.PublicKey)
if !ecdsa.Verify(ecdsaPublicKey, hashBytes, new(big.Int).SetBytes(sig.ECDSASigR.bytes), new(big.Int).SetBytes(sig.ECDSASigS.bytes)) {
return errors.SignatureError("ECDSA verification failure")
}
return nil
case PubKeyAlgoEdDSA:
if !pk.edk.Verify(hashBytes, sig.EdDSASigR, sig.EdDSASigS) {
return errors.SignatureError("EdDSA verification failure")
}
return nil
default:
return errors.SignatureError("Unsupported public key algorithm used in signature")
}
panic("unreachable")
}
// VerifySignatureV3 returns nil iff sig is a valid signature, made by this
// public key, of the data hashed into signed. signed is mutated by this call.
func (pk *PublicKey) VerifySignatureV3(signed hash.Hash, sig *SignatureV3) (err error) {
if !pk.CanSign() {
return errors.InvalidArgumentError("public key cannot generate signatures")
}
suffix := make([]byte, 5)
suffix[0] = byte(sig.SigType)
binary.BigEndian.PutUint32(suffix[1:], uint32(sig.CreationTime.Unix()))
signed.Write(suffix)
hashBytes := signed.Sum(nil)
if hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1] {
return errors.SignatureError("hash tag doesn't match")
}
if pk.PubKeyAlgo != sig.PubKeyAlgo {
return errors.InvalidArgumentError("public key and signature use different algorithms")
}
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
rsaPublicKey := pk.PublicKey.(*rsa.PublicKey)
if err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes); err != nil {
return errors.SignatureError("RSA verification failure")
}
return
case PubKeyAlgoDSA:
dsaPublicKey := pk.PublicKey.(*dsa.PublicKey)
// Need to truncate hashBytes to match FIPS 186-3 section 4.6.
subgroupSize := (dsaPublicKey.Q.BitLen() + 7) / 8
if len(hashBytes) > subgroupSize {
hashBytes = hashBytes[:subgroupSize]
}
if !dsa.Verify(dsaPublicKey, hashBytes, new(big.Int).SetBytes(sig.DSASigR.bytes), new(big.Int).SetBytes(sig.DSASigS.bytes)) {
return errors.SignatureError("DSA verification failure")
}
return nil
default:
panic("shouldn't happen")
}
panic("unreachable")
}
// keySignatureHash returns a Hash of the message that needs to be signed for
// pk to assert a subkey relationship to signed.
func keySignatureHash(pk, signed signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
updateKeySignatureHash(pk, signed, h)
return
}
// updateKeySignatureHash does the actual hash updates for keySignatureHash.
func updateKeySignatureHash(pk, signed signingKey, h hash.Hash) {
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
signed.SerializeSignaturePrefix(h)
signed.serializeWithoutHeaders(h)
}
// VerifyKeySignature returns nil iff sig is a valid signature, made by this
// public key, of signed.
func (pk *PublicKey) VerifyKeySignature(signed *PublicKey, sig *Signature) error {
h, err := keySignatureHash(pk, signed, sig.Hash)
if err != nil {
return err
}
if err = pk.VerifySignature(h, sig); err != nil {
return err
}
if sig.FlagSign {
// BUG(maxtaco)
//
// We should check for more than FlagsSign here, because if
// you read keys.go, we can sometimes use signing subkeys even if they're
// not explicitly flagged as such. However, so doing fails lots of currently
// working tests, so I'm not going to do much here.
//
// In other words, we should have this disjunction in the condition above:
//
// || (!sig.FlagsValid && pk.PubKeyAlgo.CanSign()) {
//
// Signing subkeys must be cross-signed. See
// https://www.gnupg.org/faq/subkey-cross-certify.html.
if sig.EmbeddedSignature == nil {
return errors.StructuralError("signing subkey is missing cross-signature")
}
// Verify the cross-signature. This is calculated over the same
// data as the main signature, so we cannot just recursively
// call signed.VerifyKeySignature(...)
if h, err = keySignatureHash(pk, signed, sig.EmbeddedSignature.Hash); err != nil {
return errors.StructuralError("error while hashing for cross-signature: " + err.Error())
}
if err := signed.VerifySignature(h, sig.EmbeddedSignature); err != nil {
return errors.StructuralError("error while verifying cross-signature: " + err.Error())
}
}
return nil
}
func keyRevocationHash(pk signingKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
return
}
// VerifyRevocationSignature returns nil iff sig is a valid signature, made by this
// public key.
func (pk *PublicKey) VerifyRevocationSignature(revokedKey *PublicKey, sig *Signature) (err error) {
h, err := keyRevocationHash(revokedKey, sig.Hash)
if err != nil {
return err
}
return pk.VerifySignature(h, sig)
}
type teeHash struct {
h hash.Hash
}
func (t teeHash) Write(b []byte) (n int, err error) {
fmt.Printf("hash -> %s %+v\n", string(b), b)
return t.h.Write(b)
}
func (t teeHash) Sum(b []byte) []byte { return t.h.Sum(b) }
func (t teeHash) Reset() { t.h.Reset() }
func (t teeHash) Size() int { return t.h.Size() }
func (t teeHash) BlockSize() int { return t.h.BlockSize() }
// userIdSignatureHash returns a Hash of the message that needs to be signed
// to assert that pk is a valid key for id.
func userIdSignatureHash(id string, pk *PublicKey, hashFunc crypto.Hash) (h hash.Hash, err error) {
if !hashFunc.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hashFunc.New()
updateUserIdSignatureHash(id, pk, h)
return
}
// updateUserIdSignatureHash does the actual hash updates for
// userIdSignatureHash.
func updateUserIdSignatureHash(id string, pk *PublicKey, h hash.Hash) {
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
var buf [5]byte
buf[0] = 0xb4
buf[1] = byte(len(id) >> 24)
buf[2] = byte(len(id) >> 16)
buf[3] = byte(len(id) >> 8)
buf[4] = byte(len(id))
h.Write(buf[:])
h.Write([]byte(id))
return
}
// VerifyUserIdSignature returns nil iff sig is a valid signature, made by this
// public key, that id is the identity of pub.
func (pk *PublicKey) VerifyUserIdSignature(id string, pub *PublicKey, sig *Signature) (err error) {
h, err := userIdSignatureHash(id, pub, sig.Hash)
if err != nil {
return err
}
return pk.VerifySignature(h, sig)
}
// VerifyUserIdSignatureV3 returns nil iff sig is a valid signature, made by this
// public key, that id is the identity of pub.
func (pk *PublicKey) VerifyUserIdSignatureV3(id string, pub *PublicKey, sig *SignatureV3) (err error) {
h, err := userIdSignatureV3Hash(id, pub, sig.Hash)
if err != nil {
return err
}
return pk.VerifySignatureV3(h, sig)
}
// KeyIdString returns the public key's fingerprint in capital hex
// (e.g. "6C7EE1B8621CC013").
func (pk *PublicKey) KeyIdString() string {
return fmt.Sprintf("%X", pk.Fingerprint[12:20])
}
// KeyIdShortString returns the short form of public key's fingerprint
// in capital hex, as shown by gpg --list-keys (e.g. "621CC013").
func (pk *PublicKey) KeyIdShortString() string {
return fmt.Sprintf("%X", pk.Fingerprint[16:20])
}
// A parsedMPI is used to store the contents of a big integer, along with the
// bit length that was specified in the original input. This allows the MPI to
// be reserialized exactly.
type parsedMPI struct {
bytes []byte
bitLength uint16
}
// writeMPIs is a utility function for serializing several big integers to the
// given Writer.
func writeMPIs(w io.Writer, mpis ...parsedMPI) (err error) {
for _, mpi := range mpis {
err = writeMPI(w, mpi.bitLength, mpi.bytes)
if err != nil {
return
}
}
return
}
// BitLength returns the bit length for the given public key. Used for
// displaying key information, actual buffers and BigInts inside may
// have non-matching different size if the key is invalid.
func (pk *PublicKey) BitLength() (bitLength uint16, err error) {
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
bitLength = pk.n.bitLength
case PubKeyAlgoDSA:
bitLength = pk.p.bitLength
case PubKeyAlgoElGamal:
bitLength = pk.p.bitLength
case PubKeyAlgoECDH:
ecdhPublicKey := pk.PublicKey.(*ecdh.PublicKey)
bitLength = uint16(ecdhPublicKey.Curve.Params().BitSize)
case PubKeyAlgoECDSA:
ecdsaPublicKey := pk.PublicKey.(*ecdsa.PublicKey)
bitLength = uint16(ecdsaPublicKey.Curve.Params().BitSize)
case PubKeyAlgoEdDSA:
// EdDSA only support ed25519 curves right now, just return
// the length. Also, we don't have any PublicKey.Curve object
// to look the size up from.
bitLength = 256
default:
err = errors.InvalidArgumentError("bad public-key algorithm")
}
return
}

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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"crypto"
"crypto/md5"
"encoding/binary"
"fmt"
"hash"
"io"
"math/big"
"strconv"
"time"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/rsa"
)
// PublicKeyV3 represents older, version 3 public keys. These keys are less secure and
// should not be used for signing or encrypting. They are supported here only for
// parsing version 3 key material and validating signatures.
// See RFC 4880, section 5.5.2.
type PublicKeyV3 struct {
CreationTime time.Time
DaysToExpire uint16
PubKeyAlgo PublicKeyAlgorithm
PublicKey *rsa.PublicKey
Fingerprint [16]byte
KeyId uint64
IsSubkey bool
n, e parsedMPI
}
// newRSAPublicKeyV3 returns a PublicKey that wraps the given rsa.PublicKey.
// Included here for testing purposes only. RFC 4880, section 5.5.2:
// "an implementation MUST NOT generate a V3 key, but MAY accept it."
func newRSAPublicKeyV3(creationTime time.Time, pub *rsa.PublicKey) *PublicKeyV3 {
pk := &PublicKeyV3{
CreationTime: creationTime,
PublicKey: pub,
n: FromBig(pub.N),
e: FromBig(big.NewInt(int64(pub.E))),
}
pk.setFingerPrintAndKeyId()
return pk
}
func (pk *PublicKeyV3) parse(r io.Reader) (err error) {
// RFC 4880, section 5.5.2
var buf [8]byte
if _, err = readFull(r, buf[:]); err != nil {
return
}
if buf[0] < 2 || buf[0] > 3 {
return errors.UnsupportedError("public key version")
}
pk.CreationTime = time.Unix(int64(uint32(buf[1])<<24|uint32(buf[2])<<16|uint32(buf[3])<<8|uint32(buf[4])), 0)
pk.DaysToExpire = binary.BigEndian.Uint16(buf[5:7])
pk.PubKeyAlgo = PublicKeyAlgorithm(buf[7])
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
err = pk.parseRSA(r)
default:
err = errors.UnsupportedError("public key type: " + strconv.Itoa(int(pk.PubKeyAlgo)))
}
if err != nil {
return
}
pk.setFingerPrintAndKeyId()
return
}
func (pk *PublicKeyV3) setFingerPrintAndKeyId() {
// RFC 4880, section 12.2
fingerPrint := md5.New()
fingerPrint.Write(pk.n.bytes)
fingerPrint.Write(pk.e.bytes)
fingerPrint.Sum(pk.Fingerprint[:0])
pk.KeyId = binary.BigEndian.Uint64(pk.n.bytes[len(pk.n.bytes)-8:])
}
// parseRSA parses RSA public key material from the given Reader. See RFC 4880,
// section 5.5.2.
func (pk *PublicKeyV3) parseRSA(r io.Reader) (err error) {
if pk.n.bytes, pk.n.bitLength, err = readMPI(r); err != nil {
return
}
if pk.e.bytes, pk.e.bitLength, err = readMPI(r); err != nil {
return
}
// RFC 4880 Section 12.2 requires the low 8 bytes of the
// modulus to form the key id.
if len(pk.n.bytes) < 8 {
return errors.StructuralError("v3 public key modulus is too short")
}
if len(pk.e.bytes) > 7 {
err = errors.UnsupportedError("large public exponent")
return
}
rsa := &rsa.PublicKey{N: new(big.Int).SetBytes(pk.n.bytes)}
for i := 0; i < len(pk.e.bytes); i++ {
rsa.E <<= 8
rsa.E |= int64(pk.e.bytes[i])
}
pk.PublicKey = rsa
return
}
// SerializeSignaturePrefix writes the prefix for this public key to the given Writer.
// The prefix is used when calculating a signature over this public key. See
// RFC 4880, section 5.2.4.
func (pk *PublicKeyV3) SerializeSignaturePrefix(w io.Writer) {
var pLength uint16
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
pLength += 2 + uint16(len(pk.n.bytes))
pLength += 2 + uint16(len(pk.e.bytes))
default:
panic("unknown public key algorithm")
}
pLength += 6
w.Write([]byte{0x99, byte(pLength >> 8), byte(pLength)})
return
}
func (pk *PublicKeyV3) Serialize(w io.Writer) (err error) {
length := 8 // 8 byte header
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
length += 2 + len(pk.n.bytes)
length += 2 + len(pk.e.bytes)
default:
panic("unknown public key algorithm")
}
packetType := packetTypePublicKey
if pk.IsSubkey {
packetType = packetTypePublicSubkey
}
if err = serializeHeader(w, packetType, length); err != nil {
return
}
return pk.serializeWithoutHeaders(w)
}
// serializeWithoutHeaders marshals the PublicKey to w in the form of an
// OpenPGP public key packet, not including the packet header.
func (pk *PublicKeyV3) serializeWithoutHeaders(w io.Writer) (err error) {
var buf [8]byte
// Version 3
buf[0] = 3
// Creation time
t := uint32(pk.CreationTime.Unix())
buf[1] = byte(t >> 24)
buf[2] = byte(t >> 16)
buf[3] = byte(t >> 8)
buf[4] = byte(t)
// Days to expire
buf[5] = byte(pk.DaysToExpire >> 8)
buf[6] = byte(pk.DaysToExpire)
// Public key algorithm
buf[7] = byte(pk.PubKeyAlgo)
if _, err = w.Write(buf[:]); err != nil {
return
}
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
return writeMPIs(w, pk.n, pk.e)
}
return errors.InvalidArgumentError("bad public-key algorithm")
}
// CanSign returns true iff this public key can generate signatures
func (pk *PublicKeyV3) CanSign() bool {
return pk.PubKeyAlgo != PubKeyAlgoRSAEncryptOnly
}
// VerifySignatureV3 returns nil iff sig is a valid signature, made by this
// public key, of the data hashed into signed. signed is mutated by this call.
func (pk *PublicKeyV3) VerifySignatureV3(signed hash.Hash, sig *SignatureV3) (err error) {
if !pk.CanSign() {
return errors.InvalidArgumentError("public key cannot generate signatures")
}
suffix := make([]byte, 5)
suffix[0] = byte(sig.SigType)
binary.BigEndian.PutUint32(suffix[1:], uint32(sig.CreationTime.Unix()))
signed.Write(suffix)
hashBytes := signed.Sum(nil)
if hashBytes[0] != sig.HashTag[0] || hashBytes[1] != sig.HashTag[1] {
return errors.SignatureError("hash tag doesn't match")
}
if pk.PubKeyAlgo != sig.PubKeyAlgo {
return errors.InvalidArgumentError("public key and signature use different algorithms")
}
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
if err = rsa.VerifyPKCS1v15(pk.PublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes); err != nil {
return errors.SignatureError("RSA verification failure")
}
return
default:
// V3 public keys only support RSA.
panic("shouldn't happen")
}
panic("unreachable")
}
// VerifyUserIdSignatureV3 returns nil iff sig is a valid signature, made by this
// public key, that id is the identity of pub.
func (pk *PublicKeyV3) VerifyUserIdSignatureV3(id string, pub *PublicKeyV3, sig *SignatureV3) (err error) {
h, err := userIdSignatureV3Hash(id, pk, sig.Hash)
if err != nil {
return err
}
return pk.VerifySignatureV3(h, sig)
}
// VerifyKeySignatureV3 returns nil iff sig is a valid signature, made by this
// public key, of signed.
func (pk *PublicKeyV3) VerifyKeySignatureV3(signed *PublicKeyV3, sig *SignatureV3) (err error) {
h, err := keySignatureHash(pk, signed, sig.Hash)
if err != nil {
return err
}
return pk.VerifySignatureV3(h, sig)
}
// userIdSignatureV3Hash returns a Hash of the message that needs to be signed
// to assert that pk is a valid key for id.
func userIdSignatureV3Hash(id string, pk signingKey, hfn crypto.Hash) (h hash.Hash, err error) {
if !hfn.Available() {
return nil, errors.UnsupportedError("hash function")
}
h = hfn.New()
// RFC 4880, section 5.2.4
pk.SerializeSignaturePrefix(h)
pk.serializeWithoutHeaders(h)
h.Write([]byte(id))
return
}
// KeyIdString returns the public key's fingerprint in capital hex
// (e.g. "6C7EE1B8621CC013").
func (pk *PublicKeyV3) KeyIdString() string {
return fmt.Sprintf("%X", pk.KeyId)
}
// KeyIdShortString returns the short form of public key's fingerprint
// in capital hex, as shown by gpg --list-keys (e.g. "621CC013").
func (pk *PublicKeyV3) KeyIdShortString() string {
return fmt.Sprintf("%X", pk.KeyId&0xFFFFFFFF)
}
// BitLength returns the bit length for the given public key.
func (pk *PublicKeyV3) BitLength() (bitLength uint16, err error) {
switch pk.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly, PubKeyAlgoRSASignOnly:
bitLength = pk.n.bitLength
default:
err = errors.InvalidArgumentError("bad public-key algorithm")
}
return
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"io"
"github.com/keybase/go-crypto/openpgp/errors"
)
// Reader reads packets from an io.Reader and allows packets to be 'unread' so
// that they result from the next call to Next.
type Reader struct {
q []Packet
readers []io.Reader
}
// New io.Readers are pushed when a compressed or encrypted packet is processed
// and recursively treated as a new source of packets. However, a carefully
// crafted packet can trigger an infinite recursive sequence of packets. See
// http://mumble.net/~campbell/misc/pgp-quine
// https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2013-4402
// This constant limits the number of recursive packets that may be pushed.
const maxReaders = 32
// Next returns the most recently unread Packet, or reads another packet from
// the top-most io.Reader. Unknown packet types are skipped.
func (r *Reader) Next() (p Packet, err error) {
if len(r.q) > 0 {
p = r.q[len(r.q)-1]
r.q = r.q[:len(r.q)-1]
return
}
for len(r.readers) > 0 {
p, err = Read(r.readers[len(r.readers)-1])
if err == nil {
return
}
if err == io.EOF {
r.readers = r.readers[:len(r.readers)-1]
continue
}
if _, ok := err.(errors.UnknownPacketTypeError); !ok {
return nil, err
}
}
return nil, io.EOF
}
// Push causes the Reader to start reading from a new io.Reader. When an EOF
// error is seen from the new io.Reader, it is popped and the Reader continues
// to read from the next most recent io.Reader. Push returns a StructuralError
// if pushing the reader would exceed the maximum recursion level, otherwise it
// returns nil.
func (r *Reader) Push(reader io.Reader) (err error) {
if len(r.readers) >= maxReaders {
return errors.StructuralError("too many layers of packets")
}
r.readers = append(r.readers, reader)
return nil
}
// Unread causes the given Packet to be returned from the next call to Next.
func (r *Reader) Unread(p Packet) {
r.q = append(r.q, p)
}
func NewReader(r io.Reader) *Reader {
return &Reader{
q: nil,
readers: []io.Reader{r},
}
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"crypto"
"crypto/dsa"
"crypto/ecdsa"
"encoding/binary"
"hash"
"io"
"strconv"
"time"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/s2k"
"github.com/keybase/go-crypto/rsa"
)
const (
// See RFC 4880, section 5.2.3.21 for details.
KeyFlagCertify = 1 << iota
KeyFlagSign
KeyFlagEncryptCommunications
KeyFlagEncryptStorage
)
// Signer can be implemented by application code to do actual signing.
type Signer interface {
hash.Hash
Sign(sig *Signature) error
KeyId() uint64
PublicKeyAlgo() PublicKeyAlgorithm
}
// RevocationKey represents designated revoker packet. See RFC 4880
// section 5.2.3.15 for details.
type RevocationKey struct {
Class byte
PublicKeyAlgo PublicKeyAlgorithm
Fingerprint []byte
}
// KeyFlagBits holds boolean whether any usage flags were provided in
// the signature and BitField with KeyFlag* flags.
type KeyFlagBits struct {
Valid bool
BitField byte
}
// Signature represents a signature. See RFC 4880, section 5.2.
type Signature struct {
SigType SignatureType
PubKeyAlgo PublicKeyAlgorithm
Hash crypto.Hash
// HashSuffix is extra data that is hashed in after the signed data.
HashSuffix []byte
// HashTag contains the first two bytes of the hash for fast rejection
// of bad signed data.
HashTag [2]byte
CreationTime time.Time
RSASignature parsedMPI
DSASigR, DSASigS parsedMPI
ECDSASigR, ECDSASigS parsedMPI
EdDSASigR, EdDSASigS parsedMPI
// rawSubpackets contains the unparsed subpackets, in order.
rawSubpackets []outputSubpacket
// The following are optional so are nil when not included in the
// signature.
SigLifetimeSecs, KeyLifetimeSecs *uint32
PreferredSymmetric, PreferredHash, PreferredCompression []uint8
PreferredKeyServer string
IssuerKeyId *uint64
IsPrimaryId *bool
IssuerFingerprint []byte
// FlagsValid is set if any flags were given. See RFC 4880, section
// 5.2.3.21 for details.
FlagsValid bool
FlagCertify, FlagSign, FlagEncryptCommunications, FlagEncryptStorage bool
// RevocationReason is set if this signature has been revoked.
// See RFC 4880, section 5.2.3.23 for details.
RevocationReason *uint8
RevocationReasonText string
// PolicyURI is optional. See RFC 4880, Section 5.2.3.20 for details
PolicyURI string
// Regex is a regex that can match a PGP UID. See RFC 4880, 5.2.3.14 for details
Regex string
// MDC is set if this signature has a feature packet that indicates
// support for MDC subpackets.
MDC bool
// EmbeddedSignature, if non-nil, is a signature of the parent key, by
// this key. This prevents an attacker from claiming another's signing
// subkey as their own.
EmbeddedSignature *Signature
// StubbedOutCriticalError is not fail-stop, since it shouldn't break key parsing
// when appearing in WoT-style cross signatures. But it should prevent a signature
// from being applied to a primary or subkey.
StubbedOutCriticalError error
// DesignaterRevoker will be present if this signature certifies a
// designated revoking key id (3rd party key that can sign
// revocation for this key).
DesignatedRevoker *RevocationKey
outSubpackets []outputSubpacket
}
func (sig *Signature) parse(r io.Reader) (err error) {
// RFC 4880, section 5.2.3
var buf [5]byte
_, err = readFull(r, buf[:1])
if err != nil {
return
}
if buf[0] != 4 {
err = errors.UnsupportedError("signature packet version " + strconv.Itoa(int(buf[0])))
return
}
_, err = readFull(r, buf[:5])
if err != nil {
return
}
sig.SigType = SignatureType(buf[0])
sig.PubKeyAlgo = PublicKeyAlgorithm(buf[1])
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly, PubKeyAlgoDSA, PubKeyAlgoECDSA, PubKeyAlgoEdDSA:
default:
err = errors.UnsupportedError("public key algorithm " + strconv.Itoa(int(sig.PubKeyAlgo)))
return
}
var ok bool
sig.Hash, ok = s2k.HashIdToHash(buf[2])
if !ok {
return errors.UnsupportedError("hash function " + strconv.Itoa(int(buf[2])))
}
hashedSubpacketsLength := int(buf[3])<<8 | int(buf[4])
l := 6 + hashedSubpacketsLength
sig.HashSuffix = make([]byte, l+6)
sig.HashSuffix[0] = 4
copy(sig.HashSuffix[1:], buf[:5])
hashedSubpackets := sig.HashSuffix[6:l]
_, err = readFull(r, hashedSubpackets)
if err != nil {
return
}
// See RFC 4880, section 5.2.4
trailer := sig.HashSuffix[l:]
trailer[0] = 4
trailer[1] = 0xff
trailer[2] = uint8(l >> 24)
trailer[3] = uint8(l >> 16)
trailer[4] = uint8(l >> 8)
trailer[5] = uint8(l)
err = parseSignatureSubpackets(sig, hashedSubpackets, true)
if err != nil {
return
}
_, err = readFull(r, buf[:2])
if err != nil {
return
}
unhashedSubpacketsLength := int(buf[0])<<8 | int(buf[1])
unhashedSubpackets := make([]byte, unhashedSubpacketsLength)
_, err = readFull(r, unhashedSubpackets)
if err != nil {
return
}
err = parseSignatureSubpackets(sig, unhashedSubpackets, false)
if err != nil {
return
}
_, err = readFull(r, sig.HashTag[:2])
if err != nil {
return
}
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
sig.RSASignature.bytes, sig.RSASignature.bitLength, err = readMPI(r)
case PubKeyAlgoDSA:
sig.DSASigR.bytes, sig.DSASigR.bitLength, err = readMPI(r)
if err == nil {
sig.DSASigS.bytes, sig.DSASigS.bitLength, err = readMPI(r)
}
case PubKeyAlgoEdDSA:
sig.EdDSASigR.bytes, sig.EdDSASigR.bitLength, err = readMPI(r)
if err == nil {
sig.EdDSASigS.bytes, sig.EdDSASigS.bitLength, err = readMPI(r)
}
case PubKeyAlgoECDSA:
sig.ECDSASigR.bytes, sig.ECDSASigR.bitLength, err = readMPI(r)
if err == nil {
sig.ECDSASigS.bytes, sig.ECDSASigS.bitLength, err = readMPI(r)
}
default:
panic("unreachable")
}
return
}
// parseSignatureSubpackets parses subpackets of the main signature packet. See
// RFC 4880, section 5.2.3.1.
func parseSignatureSubpackets(sig *Signature, subpackets []byte, isHashed bool) (err error) {
for len(subpackets) > 0 {
subpackets, err = parseSignatureSubpacket(sig, subpackets, isHashed)
if err != nil {
return
}
}
if sig.CreationTime.IsZero() {
err = errors.StructuralError("no creation time in signature")
}
return
}
type signatureSubpacketType uint8
const (
creationTimeSubpacket signatureSubpacketType = 2
signatureExpirationSubpacket signatureSubpacketType = 3
regularExpressionSubpacket signatureSubpacketType = 6
keyExpirationSubpacket signatureSubpacketType = 9
prefSymmetricAlgosSubpacket signatureSubpacketType = 11
revocationKey signatureSubpacketType = 12
issuerSubpacket signatureSubpacketType = 16
prefHashAlgosSubpacket signatureSubpacketType = 21
prefCompressionSubpacket signatureSubpacketType = 22
prefKeyServerSubpacket signatureSubpacketType = 24
primaryUserIdSubpacket signatureSubpacketType = 25
policyURISubpacket signatureSubpacketType = 26
keyFlagsSubpacket signatureSubpacketType = 27
reasonForRevocationSubpacket signatureSubpacketType = 29
featuresSubpacket signatureSubpacketType = 30
embeddedSignatureSubpacket signatureSubpacketType = 32
issuerFingerprint signatureSubpacketType = 33
)
// parseSignatureSubpacket parses a single subpacket. len(subpacket) is >= 1.
func parseSignatureSubpacket(sig *Signature, subpacket []byte, isHashed bool) (rest []byte, err error) {
// RFC 4880, section 5.2.3.1
var (
length uint32
packetType signatureSubpacketType
isCritical bool
)
switch {
case subpacket[0] < 192:
length = uint32(subpacket[0])
subpacket = subpacket[1:]
case subpacket[0] < 255:
if len(subpacket) < 2 {
goto Truncated
}
length = uint32(subpacket[0]-192)<<8 + uint32(subpacket[1]) + 192
subpacket = subpacket[2:]
default:
if len(subpacket) < 5 {
goto Truncated
}
length = uint32(subpacket[1])<<24 |
uint32(subpacket[2])<<16 |
uint32(subpacket[3])<<8 |
uint32(subpacket[4])
subpacket = subpacket[5:]
}
if length > uint32(len(subpacket)) {
goto Truncated
}
rest = subpacket[length:]
subpacket = subpacket[:length]
if len(subpacket) == 0 {
err = errors.StructuralError("zero length signature subpacket")
return
}
packetType = signatureSubpacketType(subpacket[0] & 0x7f)
isCritical = subpacket[0]&0x80 == 0x80
subpacket = subpacket[1:]
sig.rawSubpackets = append(sig.rawSubpackets, outputSubpacket{isHashed, packetType, isCritical, subpacket})
switch packetType {
case creationTimeSubpacket:
if !isHashed {
err = errors.StructuralError("signature creation time in non-hashed area")
return
}
if len(subpacket) != 4 {
err = errors.StructuralError("signature creation time not four bytes")
return
}
t := binary.BigEndian.Uint32(subpacket)
sig.CreationTime = time.Unix(int64(t), 0)
case signatureExpirationSubpacket:
// Signature expiration time, section 5.2.3.10
if !isHashed {
return
}
if len(subpacket) != 4 {
err = errors.StructuralError("expiration subpacket with bad length")
return
}
sig.SigLifetimeSecs = new(uint32)
*sig.SigLifetimeSecs = binary.BigEndian.Uint32(subpacket)
case keyExpirationSubpacket:
// Key expiration time, section 5.2.3.6
if !isHashed {
return
}
if len(subpacket) != 4 {
err = errors.StructuralError("key expiration subpacket with bad length")
return
}
sig.KeyLifetimeSecs = new(uint32)
*sig.KeyLifetimeSecs = binary.BigEndian.Uint32(subpacket)
case prefSymmetricAlgosSubpacket:
// Preferred symmetric algorithms, section 5.2.3.7
if !isHashed {
return
}
sig.PreferredSymmetric = make([]byte, len(subpacket))
copy(sig.PreferredSymmetric, subpacket)
case issuerSubpacket:
// Issuer, section 5.2.3.5
if len(subpacket) != 8 {
err = errors.StructuralError("issuer subpacket with bad length")
return
}
sig.IssuerKeyId = new(uint64)
*sig.IssuerKeyId = binary.BigEndian.Uint64(subpacket)
case prefHashAlgosSubpacket:
// Preferred hash algorithms, section 5.2.3.8
if !isHashed {
return
}
sig.PreferredHash = make([]byte, len(subpacket))
copy(sig.PreferredHash, subpacket)
case prefCompressionSubpacket:
// Preferred compression algorithms, section 5.2.3.9
if !isHashed {
return
}
sig.PreferredCompression = make([]byte, len(subpacket))
copy(sig.PreferredCompression, subpacket)
case primaryUserIdSubpacket:
// Primary User ID, section 5.2.3.19
if !isHashed {
return
}
if len(subpacket) != 1 {
err = errors.StructuralError("primary user id subpacket with bad length")
return
}
sig.IsPrimaryId = new(bool)
if subpacket[0] > 0 {
*sig.IsPrimaryId = true
}
case keyFlagsSubpacket:
// Key flags, section 5.2.3.21
if !isHashed {
return
}
if len(subpacket) == 0 {
err = errors.StructuralError("empty key flags subpacket")
return
}
sig.FlagsValid = true
if subpacket[0]&KeyFlagCertify != 0 {
sig.FlagCertify = true
}
if subpacket[0]&KeyFlagSign != 0 {
sig.FlagSign = true
}
if subpacket[0]&KeyFlagEncryptCommunications != 0 {
sig.FlagEncryptCommunications = true
}
if subpacket[0]&KeyFlagEncryptStorage != 0 {
sig.FlagEncryptStorage = true
}
case reasonForRevocationSubpacket:
// Reason For Revocation, section 5.2.3.23
if !isHashed {
return
}
if len(subpacket) == 0 {
err = errors.StructuralError("empty revocation reason subpacket")
return
}
sig.RevocationReason = new(uint8)
*sig.RevocationReason = subpacket[0]
sig.RevocationReasonText = string(subpacket[1:])
case featuresSubpacket:
// Features subpacket, section 5.2.3.24 specifies a very general
// mechanism for OpenPGP implementations to signal support for new
// features. In practice, the subpacket is used exclusively to
// indicate support for MDC-protected encryption.
sig.MDC = len(subpacket) >= 1 && subpacket[0]&1 == 1
case embeddedSignatureSubpacket:
// Only usage is in signatures that cross-certify
// signing subkeys. section 5.2.3.26 describes the
// format, with its usage described in section 11.1
if sig.EmbeddedSignature != nil {
err = errors.StructuralError("Cannot have multiple embedded signatures")
return
}
sig.EmbeddedSignature = new(Signature)
// Embedded signatures are required to be v4 signatures see
// section 12.1. However, we only parse v4 signatures in this
// file anyway.
if err := sig.EmbeddedSignature.parse(bytes.NewBuffer(subpacket)); err != nil {
return nil, err
}
if sigType := sig.EmbeddedSignature.SigType; sigType != SigTypePrimaryKeyBinding {
return nil, errors.StructuralError("cross-signature has unexpected type " + strconv.Itoa(int(sigType)))
}
case policyURISubpacket:
// See RFC 4880, Section 5.2.3.20
sig.PolicyURI = string(subpacket[:])
case regularExpressionSubpacket:
sig.Regex = string(subpacket[:])
if isCritical {
sig.StubbedOutCriticalError = errors.UnsupportedError("regex support is stubbed out")
}
case prefKeyServerSubpacket:
sig.PreferredKeyServer = string(subpacket[:])
case issuerFingerprint:
// The first byte is how many bytes the fingerprint is, but we'll just
// read until the end of the subpacket, so we'll ignore it.
sig.IssuerFingerprint = append([]byte{}, subpacket[1:]...)
case revocationKey:
// Authorizes the specified key to issue revocation signatures
// for a key.
// TODO: Class octet must have bit 0x80 set. If the bit 0x40
// is set, then this means that the revocation information is
// sensitive.
sig.DesignatedRevoker = &RevocationKey{
Class: subpacket[0],
PublicKeyAlgo: PublicKeyAlgorithm(subpacket[1]),
Fingerprint: append([]byte{}, subpacket[2:]...),
}
default:
if isCritical {
err = errors.UnsupportedError("unknown critical signature subpacket type " + strconv.Itoa(int(packetType)))
return
}
}
return
Truncated:
err = errors.StructuralError("signature subpacket truncated")
return
}
// subpacketLengthLength returns the length, in bytes, of an encoded length value.
func subpacketLengthLength(length int) int {
if length < 192 {
return 1
}
if length < 16320 {
return 2
}
return 5
}
// serializeSubpacketLength marshals the given length into to.
func serializeSubpacketLength(to []byte, length int) int {
// RFC 4880, Section 4.2.2.
if length < 192 {
to[0] = byte(length)
return 1
}
if length < 16320 {
length -= 192
to[0] = byte((length >> 8) + 192)
to[1] = byte(length)
return 2
}
to[0] = 255
to[1] = byte(length >> 24)
to[2] = byte(length >> 16)
to[3] = byte(length >> 8)
to[4] = byte(length)
return 5
}
// subpacketsLength returns the serialized length, in bytes, of the given
// subpackets.
func subpacketsLength(subpackets []outputSubpacket, hashed bool) (length int) {
for _, subpacket := range subpackets {
if subpacket.hashed == hashed {
length += subpacketLengthLength(len(subpacket.contents) + 1)
length += 1 // type byte
length += len(subpacket.contents)
}
}
return
}
// serializeSubpackets marshals the given subpackets into to.
func serializeSubpackets(to []byte, subpackets []outputSubpacket, hashed bool) {
for _, subpacket := range subpackets {
if subpacket.hashed == hashed {
n := serializeSubpacketLength(to, len(subpacket.contents)+1)
to[n] = byte(subpacket.subpacketType)
to = to[1+n:]
n = copy(to, subpacket.contents)
to = to[n:]
}
}
return
}
// KeyExpired returns whether sig is a self-signature of a key that has
// expired.
func (sig *Signature) KeyExpired(currentTime time.Time) bool {
if sig.KeyLifetimeSecs == nil {
return false
}
expiry := sig.CreationTime.Add(time.Duration(*sig.KeyLifetimeSecs) * time.Second)
return currentTime.After(expiry)
}
// ExpiresBeforeOther checks if other signature has expiration at
// later date than sig.
func (sig *Signature) ExpiresBeforeOther(other *Signature) bool {
if sig.KeyLifetimeSecs == nil {
// This sig never expires, or has infinitely long expiration
// time.
return false
} else if other.KeyLifetimeSecs == nil {
// This sig expires at some non-infinite point, but the other
// sig never expires.
return true
}
getExpiryDate := func(s *Signature) time.Time {
return s.CreationTime.Add(time.Duration(*s.KeyLifetimeSecs) * time.Second)
}
return getExpiryDate(other).After(getExpiryDate(sig))
}
// buildHashSuffix constructs the HashSuffix member of sig in preparation for signing.
func (sig *Signature) buildHashSuffix() (err error) {
hashedSubpacketsLen := subpacketsLength(sig.outSubpackets, true)
var ok bool
l := 6 + hashedSubpacketsLen
sig.HashSuffix = make([]byte, l+6)
sig.HashSuffix[0] = 4
sig.HashSuffix[1] = uint8(sig.SigType)
sig.HashSuffix[2] = uint8(sig.PubKeyAlgo)
sig.HashSuffix[3], ok = s2k.HashToHashId(sig.Hash)
if !ok {
sig.HashSuffix = nil
return errors.InvalidArgumentError("hash cannot be represented in OpenPGP: " + strconv.Itoa(int(sig.Hash)))
}
sig.HashSuffix[4] = byte(hashedSubpacketsLen >> 8)
sig.HashSuffix[5] = byte(hashedSubpacketsLen)
serializeSubpackets(sig.HashSuffix[6:l], sig.outSubpackets, true)
trailer := sig.HashSuffix[l:]
trailer[0] = 4
trailer[1] = 0xff
trailer[2] = byte(l >> 24)
trailer[3] = byte(l >> 16)
trailer[4] = byte(l >> 8)
trailer[5] = byte(l)
return
}
func (sig *Signature) signPrepareHash(h hash.Hash) (digest []byte, err error) {
err = sig.buildHashSuffix()
if err != nil {
return
}
h.Write(sig.HashSuffix)
digest = h.Sum(nil)
copy(sig.HashTag[:], digest)
return
}
// Sign signs a message with a private key. The hash, h, must contain
// the hash of the message to be signed and will be mutated by this function.
// On success, the signature is stored in sig. Call Serialize to write it out.
// If config is nil, sensible defaults will be used.
func (sig *Signature) Sign(h hash.Hash, priv *PrivateKey, config *Config) (err error) {
signer, hashIsSigner := h.(Signer)
if !hashIsSigner && (priv == nil || priv.PrivateKey == nil) {
err = errors.InvalidArgumentError("attempting to sign with nil PrivateKey")
return
}
sig.outSubpackets = sig.buildSubpackets()
digest, err := sig.signPrepareHash(h)
if err != nil {
return
}
if hashIsSigner {
err = signer.Sign(sig)
return
}
switch priv.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
sig.RSASignature.bytes, err = rsa.SignPKCS1v15(config.Random(), priv.PrivateKey.(*rsa.PrivateKey), sig.Hash, digest)
sig.RSASignature.bitLength = uint16(8 * len(sig.RSASignature.bytes))
case PubKeyAlgoDSA:
dsaPriv := priv.PrivateKey.(*dsa.PrivateKey)
// Need to truncate hashBytes to match FIPS 186-3 section 4.6.
subgroupSize := (dsaPriv.Q.BitLen() + 7) / 8
if len(digest) > subgroupSize {
digest = digest[:subgroupSize]
}
r, s, err := dsa.Sign(config.Random(), dsaPriv, digest)
if err == nil {
sig.DSASigR.bytes = r.Bytes()
sig.DSASigR.bitLength = uint16(8 * len(sig.DSASigR.bytes))
sig.DSASigS.bytes = s.Bytes()
sig.DSASigS.bitLength = uint16(8 * len(sig.DSASigS.bytes))
}
case PubKeyAlgoECDSA:
r, s, err := ecdsa.Sign(config.Random(), priv.PrivateKey.(*ecdsa.PrivateKey), digest)
if err == nil {
sig.ECDSASigR = FromBig(r)
sig.ECDSASigS = FromBig(s)
}
case PubKeyAlgoEdDSA:
r, s, err := priv.PrivateKey.(*EdDSAPrivateKey).Sign(digest)
if err == nil {
sig.EdDSASigR = FromBytes(r)
sig.EdDSASigS = FromBytes(s)
}
default:
err = errors.UnsupportedError("public key algorithm: " + strconv.Itoa(int(sig.PubKeyAlgo)))
}
return
}
// SignUserId computes a signature from priv, asserting that pub is a valid
// key for the identity id. On success, the signature is stored in sig. Call
// Serialize to write it out.
// If config is nil, sensible defaults will be used.
func (sig *Signature) SignUserId(id string, pub *PublicKey, priv *PrivateKey, config *Config) error {
h, err := userIdSignatureHash(id, pub, sig.Hash)
if err != nil {
return err
}
return sig.Sign(h, priv, config)
}
// SignUserIdWithSigner computes a signature from priv, asserting that pub is a
// valid key for the identity id. On success, the signature is stored in sig.
// Call Serialize to write it out.
// If config is nil, sensible defaults will be used.
func (sig *Signature) SignUserIdWithSigner(id string, pub *PublicKey, s Signer, config *Config) error {
updateUserIdSignatureHash(id, pub, s)
return sig.Sign(s, nil, config)
}
// SignKey computes a signature from priv, asserting that pub is a subkey. On
// success, the signature is stored in sig. Call Serialize to write it out.
// If config is nil, sensible defaults will be used.
func (sig *Signature) SignKey(pub *PublicKey, priv *PrivateKey, config *Config) error {
h, err := keySignatureHash(&priv.PublicKey, pub, sig.Hash)
if err != nil {
return err
}
return sig.Sign(h, priv, config)
}
// SignKeyWithSigner computes a signature using s, asserting that
// signeePubKey is a subkey. On success, the signature is stored in sig. Call
// Serialize to write it out. If config is nil, sensible defaults will be used.
func (sig *Signature) SignKeyWithSigner(signeePubKey *PublicKey, signerPubKey *PublicKey, s Signer, config *Config) error {
updateKeySignatureHash(signerPubKey, signeePubKey, s)
return sig.Sign(s, nil, config)
}
// Serialize marshals sig to w. Sign, SignUserId or SignKey must have been
// called first.
func (sig *Signature) Serialize(w io.Writer) (err error) {
if len(sig.outSubpackets) == 0 {
sig.outSubpackets = sig.rawSubpackets
}
if sig.RSASignature.bytes == nil &&
sig.DSASigR.bytes == nil &&
sig.ECDSASigR.bytes == nil &&
sig.EdDSASigR.bytes == nil {
return errors.InvalidArgumentError("Signature: need to call Sign, SignUserId or SignKey before Serialize")
}
sigLength := 0
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
sigLength = 2 + len(sig.RSASignature.bytes)
case PubKeyAlgoDSA:
sigLength = 2 + len(sig.DSASigR.bytes)
sigLength += 2 + len(sig.DSASigS.bytes)
case PubKeyAlgoEdDSA:
sigLength = 2 + len(sig.EdDSASigR.bytes)
sigLength += 2 + len(sig.EdDSASigS.bytes)
case PubKeyAlgoECDSA:
sigLength = 2 + len(sig.ECDSASigR.bytes)
sigLength += 2 + len(sig.ECDSASigS.bytes)
default:
panic("impossible")
}
unhashedSubpacketsLen := subpacketsLength(sig.outSubpackets, false)
length := len(sig.HashSuffix) - 6 /* trailer not included */ +
2 /* length of unhashed subpackets */ + unhashedSubpacketsLen +
2 /* hash tag */ + sigLength
err = serializeHeader(w, packetTypeSignature, length)
if err != nil {
return
}
_, err = w.Write(sig.HashSuffix[:len(sig.HashSuffix)-6])
if err != nil {
return
}
unhashedSubpackets := make([]byte, 2+unhashedSubpacketsLen)
unhashedSubpackets[0] = byte(unhashedSubpacketsLen >> 8)
unhashedSubpackets[1] = byte(unhashedSubpacketsLen)
serializeSubpackets(unhashedSubpackets[2:], sig.outSubpackets, false)
_, err = w.Write(unhashedSubpackets)
if err != nil {
return
}
_, err = w.Write(sig.HashTag[:])
if err != nil {
return
}
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
err = writeMPIs(w, sig.RSASignature)
case PubKeyAlgoDSA:
err = writeMPIs(w, sig.DSASigR, sig.DSASigS)
case PubKeyAlgoEdDSA:
err = writeMPIs(w, sig.EdDSASigR, sig.EdDSASigS)
case PubKeyAlgoECDSA:
err = writeMPIs(w, sig.ECDSASigR, sig.ECDSASigS)
default:
panic("impossible")
}
return
}
// outputSubpacket represents a subpacket to be marshaled.
type outputSubpacket struct {
hashed bool // true if this subpacket is in the hashed area.
subpacketType signatureSubpacketType
isCritical bool
contents []byte
}
func (sig *Signature) buildSubpackets() (subpackets []outputSubpacket) {
creationTime := make([]byte, 4)
binary.BigEndian.PutUint32(creationTime, uint32(sig.CreationTime.Unix()))
subpackets = append(subpackets, outputSubpacket{true, creationTimeSubpacket, false, creationTime})
if sig.IssuerKeyId != nil {
keyId := make([]byte, 8)
binary.BigEndian.PutUint64(keyId, *sig.IssuerKeyId)
subpackets = append(subpackets, outputSubpacket{true, issuerSubpacket, false, keyId})
}
if sig.SigLifetimeSecs != nil && *sig.SigLifetimeSecs != 0 {
sigLifetime := make([]byte, 4)
binary.BigEndian.PutUint32(sigLifetime, *sig.SigLifetimeSecs)
subpackets = append(subpackets, outputSubpacket{true, signatureExpirationSubpacket, true, sigLifetime})
}
// Key flags may only appear in self-signatures or certification signatures.
if sig.FlagsValid {
subpackets = append(subpackets, outputSubpacket{true, keyFlagsSubpacket, false, []byte{sig.GetKeyFlags().BitField}})
}
// The following subpackets may only appear in self-signatures
if sig.KeyLifetimeSecs != nil && *sig.KeyLifetimeSecs != 0 {
keyLifetime := make([]byte, 4)
binary.BigEndian.PutUint32(keyLifetime, *sig.KeyLifetimeSecs)
subpackets = append(subpackets, outputSubpacket{true, keyExpirationSubpacket, true, keyLifetime})
}
if sig.IsPrimaryId != nil && *sig.IsPrimaryId {
subpackets = append(subpackets, outputSubpacket{true, primaryUserIdSubpacket, false, []byte{1}})
}
if len(sig.PreferredSymmetric) > 0 {
subpackets = append(subpackets, outputSubpacket{true, prefSymmetricAlgosSubpacket, false, sig.PreferredSymmetric})
}
if len(sig.PreferredHash) > 0 {
subpackets = append(subpackets, outputSubpacket{true, prefHashAlgosSubpacket, false, sig.PreferredHash})
}
if len(sig.PreferredCompression) > 0 {
subpackets = append(subpackets, outputSubpacket{true, prefCompressionSubpacket, false, sig.PreferredCompression})
}
return
}
func (sig *Signature) GetKeyFlags() (ret KeyFlagBits) {
if !sig.FlagsValid {
return ret
}
ret.Valid = true
if sig.FlagCertify {
ret.BitField |= KeyFlagCertify
}
if sig.FlagSign {
ret.BitField |= KeyFlagSign
}
if sig.FlagEncryptCommunications {
ret.BitField |= KeyFlagEncryptCommunications
}
if sig.FlagEncryptStorage {
ret.BitField |= KeyFlagEncryptStorage
}
return ret
}
func (f *KeyFlagBits) HasFlagCertify() bool {
return f.BitField&KeyFlagCertify != 0
}
func (f *KeyFlagBits) HasFlagSign() bool {
return f.BitField&KeyFlagSign != 0
}
func (f *KeyFlagBits) HasFlagEncryptCommunications() bool {
return f.BitField&KeyFlagEncryptCommunications != 0
}
func (f *KeyFlagBits) HasFlagEncryptStorage() bool {
return f.BitField&KeyFlagEncryptStorage != 0
}
func (f *KeyFlagBits) Merge(other KeyFlagBits) {
if other.Valid {
f.Valid = true
f.BitField |= other.BitField
}
}

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@ -0,0 +1,146 @@
// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"crypto"
"encoding/binary"
"fmt"
"io"
"strconv"
"time"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/s2k"
)
// SignatureV3 represents older version 3 signatures. These signatures are less secure
// than version 4 and should not be used to create new signatures. They are included
// here for backwards compatibility to read and validate with older key material.
// See RFC 4880, section 5.2.2.
type SignatureV3 struct {
SigType SignatureType
CreationTime time.Time
IssuerKeyId uint64
PubKeyAlgo PublicKeyAlgorithm
Hash crypto.Hash
HashTag [2]byte
RSASignature parsedMPI
DSASigR, DSASigS parsedMPI
}
func (sig *SignatureV3) parse(r io.Reader) (err error) {
// RFC 4880, section 5.2.2
var buf [8]byte
if _, err = readFull(r, buf[:1]); err != nil {
return
}
if buf[0] < 2 || buf[0] > 3 {
err = errors.UnsupportedError("signature packet version " + strconv.Itoa(int(buf[0])))
return
}
if _, err = readFull(r, buf[:1]); err != nil {
return
}
if buf[0] != 5 {
err = errors.UnsupportedError(
"invalid hashed material length " + strconv.Itoa(int(buf[0])))
return
}
// Read hashed material: signature type + creation time
if _, err = readFull(r, buf[:5]); err != nil {
return
}
sig.SigType = SignatureType(buf[0])
t := binary.BigEndian.Uint32(buf[1:5])
sig.CreationTime = time.Unix(int64(t), 0)
// Eight-octet Key ID of signer.
if _, err = readFull(r, buf[:8]); err != nil {
return
}
sig.IssuerKeyId = binary.BigEndian.Uint64(buf[:])
// Public-key and hash algorithm
if _, err = readFull(r, buf[:2]); err != nil {
return
}
sig.PubKeyAlgo = PublicKeyAlgorithm(buf[0])
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly, PubKeyAlgoDSA:
default:
err = errors.UnsupportedError("public key algorithm " + strconv.Itoa(int(sig.PubKeyAlgo)))
return
}
var ok bool
if sig.Hash, ok = s2k.HashIdToHash(buf[1]); !ok {
return errors.UnsupportedError("hash function " + strconv.Itoa(int(buf[2])))
}
// Two-octet field holding left 16 bits of signed hash value.
if _, err = readFull(r, sig.HashTag[:2]); err != nil {
return
}
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
sig.RSASignature.bytes, sig.RSASignature.bitLength, err = readMPI(r)
case PubKeyAlgoDSA:
if sig.DSASigR.bytes, sig.DSASigR.bitLength, err = readMPI(r); err != nil {
return
}
sig.DSASigS.bytes, sig.DSASigS.bitLength, err = readMPI(r)
default:
panic("unreachable")
}
return
}
// Serialize marshals sig to w. Sign, SignUserId or SignKey must have been
// called first.
func (sig *SignatureV3) Serialize(w io.Writer) (err error) {
buf := make([]byte, 8)
// Write the sig type and creation time
buf[0] = byte(sig.SigType)
binary.BigEndian.PutUint32(buf[1:5], uint32(sig.CreationTime.Unix()))
if _, err = w.Write(buf[:5]); err != nil {
return
}
// Write the issuer long key ID
binary.BigEndian.PutUint64(buf[:8], sig.IssuerKeyId)
if _, err = w.Write(buf[:8]); err != nil {
return
}
// Write public key algorithm, hash ID, and hash value
buf[0] = byte(sig.PubKeyAlgo)
hashId, ok := s2k.HashToHashId(sig.Hash)
if !ok {
return errors.UnsupportedError(fmt.Sprintf("hash function %v", sig.Hash))
}
buf[1] = hashId
copy(buf[2:4], sig.HashTag[:])
if _, err = w.Write(buf[:4]); err != nil {
return
}
if sig.RSASignature.bytes == nil && sig.DSASigR.bytes == nil {
return errors.InvalidArgumentError("Signature: need to call Sign, SignUserId or SignKey before Serialize")
}
switch sig.PubKeyAlgo {
case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
err = writeMPIs(w, sig.RSASignature)
case PubKeyAlgoDSA:
err = writeMPIs(w, sig.DSASigR, sig.DSASigS)
default:
panic("impossible")
}
return
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"crypto/cipher"
"io"
"strconv"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/s2k"
)
// This is the largest session key that we'll support. Since no 512-bit cipher
// has even been seriously used, this is comfortably large.
const maxSessionKeySizeInBytes = 64
// SymmetricKeyEncrypted represents a passphrase protected session key. See RFC
// 4880, section 5.3.
type SymmetricKeyEncrypted struct {
CipherFunc CipherFunction
s2k func(out, in []byte)
encryptedKey []byte
}
const symmetricKeyEncryptedVersion = 4
func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error {
// RFC 4880, section 5.3.
var buf [2]byte
if _, err := readFull(r, buf[:]); err != nil {
return err
}
if buf[0] != symmetricKeyEncryptedVersion {
return errors.UnsupportedError("SymmetricKeyEncrypted version")
}
ske.CipherFunc = CipherFunction(buf[1])
if ske.CipherFunc.KeySize() == 0 {
return errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(buf[1])))
}
var err error
ske.s2k, err = s2k.Parse(r)
if err != nil {
return err
}
if ske.s2k == nil {
return errors.UnsupportedError("can't use dummy S2K for symmetric key encryption")
}
encryptedKey := make([]byte, maxSessionKeySizeInBytes)
// The session key may follow. We just have to try and read to find
// out. If it exists then we limit it to maxSessionKeySizeInBytes.
n, err := readFull(r, encryptedKey)
if err != nil && err != io.ErrUnexpectedEOF {
return err
}
if n != 0 {
if n == maxSessionKeySizeInBytes {
return errors.UnsupportedError("oversized encrypted session key")
}
ske.encryptedKey = encryptedKey[:n]
}
return nil
}
// Decrypt attempts to decrypt an encrypted session key and returns the key and
// the cipher to use when decrypting a subsequent Symmetrically Encrypted Data
// packet.
func (ske *SymmetricKeyEncrypted) Decrypt(passphrase []byte) ([]byte, CipherFunction, error) {
key := make([]byte, ske.CipherFunc.KeySize())
ske.s2k(key, passphrase)
if len(ske.encryptedKey) == 0 {
return key, ske.CipherFunc, nil
}
// the IV is all zeros
iv := make([]byte, ske.CipherFunc.blockSize())
c := cipher.NewCFBDecrypter(ske.CipherFunc.new(key), iv)
plaintextKey := make([]byte, len(ske.encryptedKey))
c.XORKeyStream(plaintextKey, ske.encryptedKey)
cipherFunc := CipherFunction(plaintextKey[0])
if cipherFunc.blockSize() == 0 {
return nil, ske.CipherFunc, errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(cipherFunc)))
}
plaintextKey = plaintextKey[1:]
if l := len(plaintextKey); l == 0 || l%cipherFunc.blockSize() != 0 {
return nil, cipherFunc, errors.StructuralError("length of decrypted key not a multiple of block size")
}
return plaintextKey, cipherFunc, nil
}
// SerializeSymmetricKeyEncrypted serializes a symmetric key packet to w. The
// packet contains a random session key, encrypted by a key derived from the
// given passphrase. The session key is returned and must be passed to
// SerializeSymmetricallyEncrypted.
// If config is nil, sensible defaults will be used.
func SerializeSymmetricKeyEncrypted(w io.Writer, passphrase []byte, config *Config) (key []byte, err error) {
cipherFunc := config.Cipher()
keySize := cipherFunc.KeySize()
if keySize == 0 {
return nil, errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(cipherFunc)))
}
s2kBuf := new(bytes.Buffer)
keyEncryptingKey := make([]byte, keySize)
// s2k.Serialize salts and stretches the passphrase, and writes the
// resulting key to keyEncryptingKey and the s2k descriptor to s2kBuf.
err = s2k.Serialize(s2kBuf, keyEncryptingKey, config.Random(), passphrase, &s2k.Config{Hash: config.Hash(), S2KCount: config.PasswordHashIterations()})
if err != nil {
return
}
s2kBytes := s2kBuf.Bytes()
packetLength := 2 /* header */ + len(s2kBytes) + 1 /* cipher type */ + keySize
err = serializeHeader(w, packetTypeSymmetricKeyEncrypted, packetLength)
if err != nil {
return
}
var buf [2]byte
buf[0] = symmetricKeyEncryptedVersion
buf[1] = byte(cipherFunc)
_, err = w.Write(buf[:])
if err != nil {
return
}
_, err = w.Write(s2kBytes)
if err != nil {
return
}
sessionKey := make([]byte, keySize)
_, err = io.ReadFull(config.Random(), sessionKey)
if err != nil {
return
}
iv := make([]byte, cipherFunc.blockSize())
c := cipher.NewCFBEncrypter(cipherFunc.new(keyEncryptingKey), iv)
encryptedCipherAndKey := make([]byte, keySize+1)
c.XORKeyStream(encryptedCipherAndKey, buf[1:])
c.XORKeyStream(encryptedCipherAndKey[1:], sessionKey)
_, err = w.Write(encryptedCipherAndKey)
if err != nil {
return
}
key = sessionKey
return
}

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@ -0,0 +1,291 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"crypto/cipher"
"crypto/sha1"
"crypto/subtle"
"hash"
"io"
"strconv"
"github.com/keybase/go-crypto/openpgp/errors"
)
// SymmetricallyEncrypted represents a symmetrically encrypted byte string. The
// encrypted contents will consist of more OpenPGP packets. See RFC 4880,
// sections 5.7 and 5.13.
type SymmetricallyEncrypted struct {
MDC bool // true iff this is a type 18 packet and thus has an embedded MAC.
contents io.Reader
prefix []byte
}
const symmetricallyEncryptedVersion = 1
func (se *SymmetricallyEncrypted) parse(r io.Reader) error {
if se.MDC {
// See RFC 4880, section 5.13.
var buf [1]byte
_, err := readFull(r, buf[:])
if err != nil {
return err
}
if buf[0] != symmetricallyEncryptedVersion {
return errors.UnsupportedError("unknown SymmetricallyEncrypted version")
}
}
se.contents = r
return nil
}
// Decrypt returns a ReadCloser, from which the decrypted contents of the
// packet can be read. An incorrect key can, with high probability, be detected
// immediately and this will result in a KeyIncorrect error being returned.
func (se *SymmetricallyEncrypted) Decrypt(c CipherFunction, key []byte) (io.ReadCloser, error) {
keySize := c.KeySize()
if keySize == 0 {
return nil, errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(c)))
}
if len(key) != keySize {
return nil, errors.InvalidArgumentError("SymmetricallyEncrypted: incorrect key length")
}
if se.prefix == nil {
se.prefix = make([]byte, c.blockSize()+2)
_, err := readFull(se.contents, se.prefix)
if err != nil {
return nil, err
}
} else if len(se.prefix) != c.blockSize()+2 {
return nil, errors.InvalidArgumentError("can't try ciphers with different block lengths")
}
ocfbResync := OCFBResync
if se.MDC {
// MDC packets use a different form of OCFB mode.
ocfbResync = OCFBNoResync
}
s := NewOCFBDecrypter(c.new(key), se.prefix, ocfbResync)
if s == nil {
return nil, errors.ErrKeyIncorrect
}
plaintext := cipher.StreamReader{S: s, R: se.contents}
if se.MDC {
// MDC packets have an embedded hash that we need to check.
h := sha1.New()
h.Write(se.prefix)
return &seMDCReader{in: plaintext, h: h}, nil
}
// Otherwise, we just need to wrap plaintext so that it's a valid ReadCloser.
return seReader{plaintext}, nil
}
// seReader wraps an io.Reader with a no-op Close method.
type seReader struct {
in io.Reader
}
func (ser seReader) Read(buf []byte) (int, error) {
return ser.in.Read(buf)
}
func (ser seReader) Close() error {
return nil
}
const mdcTrailerSize = 1 /* tag byte */ + 1 /* length byte */ + sha1.Size
// An seMDCReader wraps an io.Reader, maintains a running hash and keeps hold
// of the most recent 22 bytes (mdcTrailerSize). Upon EOF, those bytes form an
// MDC packet containing a hash of the previous contents which is checked
// against the running hash. See RFC 4880, section 5.13.
type seMDCReader struct {
in io.Reader
h hash.Hash
trailer [mdcTrailerSize]byte
scratch [mdcTrailerSize]byte
trailerUsed int
error bool
eof bool
}
func (ser *seMDCReader) Read(buf []byte) (n int, err error) {
if ser.error {
err = io.ErrUnexpectedEOF
return
}
if ser.eof {
err = io.EOF
return
}
// If we haven't yet filled the trailer buffer then we must do that
// first.
for ser.trailerUsed < mdcTrailerSize {
n, err = ser.in.Read(ser.trailer[ser.trailerUsed:])
ser.trailerUsed += n
if err == io.EOF {
if ser.trailerUsed != mdcTrailerSize {
n = 0
err = io.ErrUnexpectedEOF
ser.error = true
return
}
ser.eof = true
n = 0
return
}
if err != nil {
n = 0
return
}
}
// If it's a short read then we read into a temporary buffer and shift
// the data into the caller's buffer.
if len(buf) <= mdcTrailerSize {
n, err = readFull(ser.in, ser.scratch[:len(buf)])
copy(buf, ser.trailer[:n])
ser.h.Write(buf[:n])
copy(ser.trailer[:], ser.trailer[n:])
copy(ser.trailer[mdcTrailerSize-n:], ser.scratch[:])
if n < len(buf) {
ser.eof = true
err = io.EOF
}
return
}
n, err = ser.in.Read(buf[mdcTrailerSize:])
copy(buf, ser.trailer[:])
ser.h.Write(buf[:n])
copy(ser.trailer[:], buf[n:])
if err == io.EOF {
ser.eof = true
}
return
}
// This is a new-format packet tag byte for a type 19 (MDC) packet.
const mdcPacketTagByte = byte(0x80) | 0x40 | 19
func (ser *seMDCReader) Close() error {
if ser.error {
return errors.SignatureError("error during reading")
}
for !ser.eof {
// We haven't seen EOF so we need to read to the end
var buf [1024]byte
_, err := ser.Read(buf[:])
if err == io.EOF {
break
}
if err != nil {
return errors.SignatureError("error during reading")
}
}
if ser.trailer[0] != mdcPacketTagByte || ser.trailer[1] != sha1.Size {
return errors.SignatureError("MDC packet not found")
}
ser.h.Write(ser.trailer[:2])
final := ser.h.Sum(nil)
if subtle.ConstantTimeCompare(final, ser.trailer[2:]) != 1 {
return errors.SignatureError("hash mismatch")
}
return nil
}
// An seMDCWriter writes through to an io.WriteCloser while maintains a running
// hash of the data written. On close, it emits an MDC packet containing the
// running hash.
type seMDCWriter struct {
w io.WriteCloser
h hash.Hash
}
func (w *seMDCWriter) Write(buf []byte) (n int, err error) {
w.h.Write(buf)
return w.w.Write(buf)
}
func (w *seMDCWriter) Close() (err error) {
var buf [mdcTrailerSize]byte
buf[0] = mdcPacketTagByte
buf[1] = sha1.Size
w.h.Write(buf[:2])
digest := w.h.Sum(nil)
copy(buf[2:], digest)
_, err = w.w.Write(buf[:])
if err != nil {
return
}
return w.w.Close()
}
// noOpCloser is like an ioutil.NopCloser, but for an io.Writer.
type noOpCloser struct {
w io.Writer
}
func (c noOpCloser) Write(data []byte) (n int, err error) {
return c.w.Write(data)
}
func (c noOpCloser) Close() error {
return nil
}
// SerializeSymmetricallyEncrypted serializes a symmetrically encrypted packet
// to w and returns a WriteCloser to which the to-be-encrypted packets can be
// written.
// If config is nil, sensible defaults will be used.
func SerializeSymmetricallyEncrypted(w io.Writer, c CipherFunction, key []byte, config *Config) (contents io.WriteCloser, err error) {
if c.KeySize() != len(key) {
return nil, errors.InvalidArgumentError("SymmetricallyEncrypted.Serialize: bad key length")
}
writeCloser := noOpCloser{w}
ciphertext, err := serializeStreamHeader(writeCloser, packetTypeSymmetricallyEncryptedMDC)
if err != nil {
return
}
_, err = ciphertext.Write([]byte{symmetricallyEncryptedVersion})
if err != nil {
return
}
block := c.new(key)
blockSize := block.BlockSize()
iv := make([]byte, blockSize)
_, err = config.Random().Read(iv)
if err != nil {
return
}
s, prefix := NewOCFBEncrypter(block, iv, OCFBNoResync)
_, err = ciphertext.Write(prefix)
if err != nil {
return
}
plaintext := cipher.StreamWriter{S: s, W: ciphertext}
h := sha1.New()
h.Write(iv)
h.Write(iv[blockSize-2:])
contents = &seMDCWriter{w: plaintext, h: h}
return
}

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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"image"
"image/jpeg"
"io"
"io/ioutil"
)
const UserAttrImageSubpacket = 1
// UserAttribute is capable of storing other types of data about a user
// beyond name, email and a text comment. In practice, user attributes are typically used
// to store a signed thumbnail photo JPEG image of the user.
// See RFC 4880, section 5.12.
type UserAttribute struct {
Contents []*OpaqueSubpacket
}
// NewUserAttributePhoto creates a user attribute packet
// containing the given images.
func NewUserAttributePhoto(photos ...image.Image) (uat *UserAttribute, err error) {
uat = new(UserAttribute)
for _, photo := range photos {
var buf bytes.Buffer
// RFC 4880, Section 5.12.1.
data := []byte{
0x10, 0x00, // Little-endian image header length (16 bytes)
0x01, // Image header version 1
0x01, // JPEG
0, 0, 0, 0, // 12 reserved octets, must be all zero.
0, 0, 0, 0,
0, 0, 0, 0}
if _, err = buf.Write(data); err != nil {
return
}
if err = jpeg.Encode(&buf, photo, nil); err != nil {
return
}
uat.Contents = append(uat.Contents, &OpaqueSubpacket{
SubType: UserAttrImageSubpacket,
Contents: buf.Bytes()})
}
return
}
// NewUserAttribute creates a new user attribute packet containing the given subpackets.
func NewUserAttribute(contents ...*OpaqueSubpacket) *UserAttribute {
return &UserAttribute{Contents: contents}
}
func (uat *UserAttribute) parse(r io.Reader) (err error) {
// RFC 4880, section 5.13
b, err := ioutil.ReadAll(r)
if err != nil {
return
}
uat.Contents, err = OpaqueSubpackets(b)
return
}
// Serialize marshals the user attribute to w in the form of an OpenPGP packet, including
// header.
func (uat *UserAttribute) Serialize(w io.Writer) (err error) {
var buf bytes.Buffer
for _, sp := range uat.Contents {
sp.Serialize(&buf)
}
if err = serializeHeader(w, packetTypeUserAttribute, buf.Len()); err != nil {
return err
}
_, err = w.Write(buf.Bytes())
return
}
// ImageData returns zero or more byte slices, each containing
// JPEG File Interchange Format (JFIF), for each photo in the
// the user attribute packet.
func (uat *UserAttribute) ImageData() (imageData [][]byte) {
for _, sp := range uat.Contents {
if sp.SubType == UserAttrImageSubpacket && len(sp.Contents) > 16 {
imageData = append(imageData, sp.Contents[16:])
}
}
return
}

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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"io"
"io/ioutil"
"strings"
)
// UserId contains text that is intended to represent the name and email
// address of the key holder. See RFC 4880, section 5.11. By convention, this
// takes the form "Full Name (Comment) <email@example.com>"
type UserId struct {
Id string // By convention, this takes the form "Full Name (Comment) <email@example.com>" which is split out in the fields below.
Name, Comment, Email string
}
func hasInvalidCharacters(s string) bool {
for _, c := range s {
switch c {
case '(', ')', '<', '>', 0:
return true
}
}
return false
}
// NewUserId returns a UserId or nil if any of the arguments contain invalid
// characters. The invalid characters are '\x00', '(', ')', '<' and '>'
func NewUserId(name, comment, email string) *UserId {
// RFC 4880 doesn't deal with the structure of userid strings; the
// name, comment and email form is just a convention. However, there's
// no convention about escaping the metacharacters and GPG just refuses
// to create user ids where, say, the name contains a '('. We mirror
// this behaviour.
if hasInvalidCharacters(name) || hasInvalidCharacters(comment) || hasInvalidCharacters(email) {
return nil
}
uid := new(UserId)
uid.Name, uid.Comment, uid.Email = name, comment, email
uid.Id = name
if len(comment) > 0 {
if len(uid.Id) > 0 {
uid.Id += " "
}
uid.Id += "("
uid.Id += comment
uid.Id += ")"
}
if len(email) > 0 {
if len(uid.Id) > 0 {
uid.Id += " "
}
uid.Id += "<"
uid.Id += email
uid.Id += ">"
}
return uid
}
func (uid *UserId) parse(r io.Reader) (err error) {
// RFC 4880, section 5.11
b, err := ioutil.ReadAll(r)
if err != nil {
return
}
uid.Id = string(b)
uid.Name, uid.Comment, uid.Email = parseUserId(uid.Id)
return
}
// Serialize marshals uid to w in the form of an OpenPGP packet, including
// header.
func (uid *UserId) Serialize(w io.Writer) error {
err := serializeHeader(w, packetTypeUserId, len(uid.Id))
if err != nil {
return err
}
_, err = w.Write([]byte(uid.Id))
return err
}
// parseUserId extracts the name, comment and email from a user id string that
// is formatted as "Full Name (Comment) <email@example.com>".
func parseUserId(id string) (name, comment, email string) {
var n, c, e struct {
start, end int
}
var state int
for offset, rune := range id {
switch state {
case 0:
// Entering name
n.start = offset
state = 1
fallthrough
case 1:
// In name
if rune == '(' {
state = 2
n.end = offset
} else if rune == '<' {
state = 5
n.end = offset
}
case 2:
// Entering comment
c.start = offset
state = 3
fallthrough
case 3:
// In comment
if rune == ')' {
state = 4
c.end = offset
}
case 4:
// Between comment and email
if rune == '<' {
state = 5
}
case 5:
// Entering email
e.start = offset
state = 6
fallthrough
case 6:
// In email
if rune == '>' {
state = 7
e.end = offset
}
default:
// After email
}
}
switch state {
case 1:
// ended in the name
n.end = len(id)
case 3:
// ended in comment
c.end = len(id)
case 6:
// ended in email
e.end = len(id)
}
name = strings.TrimSpace(id[n.start:n.end])
comment = strings.TrimSpace(id[c.start:c.end])
email = strings.TrimSpace(id[e.start:e.end])
return
}

7
vendor/github.com/keybase/go-crypto/openpgp/patch.sh generated vendored Normal file
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@ -0,0 +1,7 @@
#!/bin/sh
patch < sig-v3.patch
patch < s2k-gnu-dummy.patch
find . -type f -name '*.go' -exec sed -i'' -e 's/golang.org\/x\/crypto\/openpgp/github.com\/keybase\/go-crypto\/openpgp/' {} \;
find . -type f -name '*.go-e' -exec rm {} \;
go test ./...

463
vendor/github.com/keybase/go-crypto/openpgp/read.go generated vendored Normal file
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package openpgp implements high level operations on OpenPGP messages.
package openpgp // import "github.com/keybase/go-crypto/openpgp"
import (
"crypto"
"crypto/hmac"
_ "crypto/sha256"
"hash"
"io"
"strconv"
"github.com/keybase/go-crypto/openpgp/armor"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/packet"
)
// SignatureType is the armor type for a PGP signature.
var SignatureType = "PGP SIGNATURE"
// readArmored reads an armored block with the given type.
func readArmored(r io.Reader, expectedType string) (body io.Reader, err error) {
block, err := armor.Decode(r)
if err != nil {
return
}
if block.Type != expectedType {
return nil, errors.InvalidArgumentError("expected '" + expectedType + "', got: " + block.Type)
}
return block.Body, nil
}
// MessageDetails contains the result of parsing an OpenPGP encrypted and/or
// signed message.
type MessageDetails struct {
IsEncrypted bool // true if the message was encrypted.
EncryptedToKeyIds []uint64 // the list of recipient key ids.
IsSymmetricallyEncrypted bool // true if a passphrase could have decrypted the message.
DecryptedWith Key // the private key used to decrypt the message, if any.
IsSigned bool // true if the message is signed.
SignedByKeyId uint64 // the key id of the signer, if any.
SignedBy *Key // the key of the signer, if available.
LiteralData *packet.LiteralData // the metadata of the contents
UnverifiedBody io.Reader // the contents of the message.
// If IsSigned is true and SignedBy is non-zero then the signature will
// be verified as UnverifiedBody is read. The signature cannot be
// checked until the whole of UnverifiedBody is read so UnverifiedBody
// must be consumed until EOF before the data can trusted. Even if a
// message isn't signed (or the signer is unknown) the data may contain
// an authentication code that is only checked once UnverifiedBody has
// been consumed. Once EOF has been seen, the following fields are
// valid. (An authentication code failure is reported as a
// SignatureError error when reading from UnverifiedBody.)
SignatureError error // nil if the signature is good.
Signature *packet.Signature // the signature packet itself, if v4 (default)
SignatureV3 *packet.SignatureV3 // the signature packet if it is a v2 or v3 signature
decrypted io.ReadCloser
}
// A PromptFunction is used as a callback by functions that may need to decrypt
// a private key, or prompt for a passphrase. It is called with a list of
// acceptable, encrypted private keys and a boolean that indicates whether a
// passphrase is usable. It should either decrypt a private key or return a
// passphrase to try. If the decrypted private key or given passphrase isn't
// correct, the function will be called again, forever. Any error returned will
// be passed up.
type PromptFunction func(keys []Key, symmetric bool) ([]byte, error)
// A keyEnvelopePair is used to store a private key with the envelope that
// contains a symmetric key, encrypted with that key.
type keyEnvelopePair struct {
key Key
encryptedKey *packet.EncryptedKey
}
// ReadMessage parses an OpenPGP message that may be signed and/or encrypted.
// The given KeyRing should contain both public keys (for signature
// verification) and, possibly encrypted, private keys for decrypting.
// If config is nil, sensible defaults will be used.
func ReadMessage(r io.Reader, keyring KeyRing, prompt PromptFunction, config *packet.Config) (md *MessageDetails, err error) {
var p packet.Packet
var symKeys []*packet.SymmetricKeyEncrypted
var pubKeys []keyEnvelopePair
var se *packet.SymmetricallyEncrypted
packets := packet.NewReader(r)
md = new(MessageDetails)
md.IsEncrypted = true
// The message, if encrypted, starts with a number of packets
// containing an encrypted decryption key. The decryption key is either
// encrypted to a public key, or with a passphrase. This loop
// collects these packets.
ParsePackets:
for {
p, err = packets.Next()
if err != nil {
return nil, err
}
switch p := p.(type) {
case *packet.SymmetricKeyEncrypted:
// This packet contains the decryption key encrypted with a passphrase.
md.IsSymmetricallyEncrypted = true
symKeys = append(symKeys, p)
case *packet.EncryptedKey:
// This packet contains the decryption key encrypted to a public key.
md.EncryptedToKeyIds = append(md.EncryptedToKeyIds, p.KeyId)
switch p.Algo {
case packet.PubKeyAlgoRSA, packet.PubKeyAlgoRSAEncryptOnly, packet.PubKeyAlgoElGamal, packet.PubKeyAlgoECDH:
break
default:
continue
}
var keys []Key
if p.KeyId == 0 {
keys = keyring.DecryptionKeys()
} else {
keys = keyring.KeysById(p.KeyId, nil)
}
for _, k := range keys {
pubKeys = append(pubKeys, keyEnvelopePair{k, p})
}
case *packet.SymmetricallyEncrypted:
se = p
break ParsePackets
case *packet.Compressed, *packet.LiteralData, *packet.OnePassSignature:
// This message isn't encrypted.
if len(symKeys) != 0 || len(pubKeys) != 0 {
return nil, errors.StructuralError("key material not followed by encrypted message")
}
packets.Unread(p)
return readSignedMessage(packets, nil, keyring)
}
}
var candidates []Key
var decrypted io.ReadCloser
// Now that we have the list of encrypted keys we need to decrypt at
// least one of them or, if we cannot, we need to call the prompt
// function so that it can decrypt a key or give us a passphrase.
FindKey:
for {
// See if any of the keys already have a private key available
candidates = candidates[:0]
candidateFingerprints := make(map[string]bool)
for _, pk := range pubKeys {
if pk.key.PrivateKey == nil {
continue
}
if !pk.key.PrivateKey.Encrypted {
if len(pk.encryptedKey.Key) == 0 {
pk.encryptedKey.Decrypt(pk.key.PrivateKey, config)
}
if len(pk.encryptedKey.Key) == 0 {
continue
}
decrypted, err = se.Decrypt(pk.encryptedKey.CipherFunc, pk.encryptedKey.Key)
if err != nil && err != errors.ErrKeyIncorrect {
return nil, err
}
if decrypted != nil {
md.DecryptedWith = pk.key
break FindKey
}
} else {
fpr := string(pk.key.PublicKey.Fingerprint[:])
if v := candidateFingerprints[fpr]; v {
continue
}
candidates = append(candidates, pk.key)
candidateFingerprints[fpr] = true
}
}
if len(candidates) == 0 && len(symKeys) == 0 {
return nil, errors.ErrKeyIncorrect
}
if prompt == nil {
return nil, errors.ErrKeyIncorrect
}
passphrase, err := prompt(candidates, len(symKeys) != 0)
if err != nil {
return nil, err
}
// Try the symmetric passphrase first
if len(symKeys) != 0 && passphrase != nil {
for _, s := range symKeys {
key, cipherFunc, err := s.Decrypt(passphrase)
if err == nil {
decrypted, err = se.Decrypt(cipherFunc, key)
if err != nil && err != errors.ErrKeyIncorrect {
return nil, err
}
if decrypted != nil {
break FindKey
}
}
}
}
}
md.decrypted = decrypted
if err := packets.Push(decrypted); err != nil {
return nil, err
}
return readSignedMessage(packets, md, keyring)
}
// readSignedMessage reads a possibly signed message if mdin is non-zero then
// that structure is updated and returned. Otherwise a fresh MessageDetails is
// used.
func readSignedMessage(packets *packet.Reader, mdin *MessageDetails, keyring KeyRing) (md *MessageDetails, err error) {
if mdin == nil {
mdin = new(MessageDetails)
}
md = mdin
var p packet.Packet
var h hash.Hash
var wrappedHash hash.Hash
FindLiteralData:
for {
p, err = packets.Next()
if err != nil {
return nil, err
}
switch p := p.(type) {
case *packet.Compressed:
if err := packets.Push(p.Body); err != nil {
return nil, err
}
case *packet.OnePassSignature:
if !p.IsLast {
return nil, errors.UnsupportedError("nested signatures")
}
h, wrappedHash, err = hashForSignature(p.Hash, p.SigType)
if err != nil {
md = nil
return
}
md.IsSigned = true
md.SignedByKeyId = p.KeyId
keys := keyring.KeysByIdUsage(p.KeyId, nil, packet.KeyFlagSign)
if len(keys) > 0 {
md.SignedBy = &keys[0]
}
case *packet.LiteralData:
md.LiteralData = p
break FindLiteralData
}
}
if md.SignedBy != nil {
md.UnverifiedBody = &signatureCheckReader{packets, h, wrappedHash, md}
} else if md.decrypted != nil {
md.UnverifiedBody = checkReader{md}
} else {
md.UnverifiedBody = md.LiteralData.Body
}
return md, nil
}
// hashForSignature returns a pair of hashes that can be used to verify a
// signature. The signature may specify that the contents of the signed message
// should be preprocessed (i.e. to normalize line endings). Thus this function
// returns two hashes. The second should be used to hash the message itself and
// performs any needed preprocessing.
func hashForSignature(hashId crypto.Hash, sigType packet.SignatureType) (hash.Hash, hash.Hash, error) {
if !hashId.Available() {
return nil, nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hashId)))
}
h := hashId.New()
switch sigType {
case packet.SigTypeBinary:
return h, h, nil
case packet.SigTypeText:
return h, NewCanonicalTextHash(h), nil
}
return nil, nil, errors.UnsupportedError("unsupported signature type: " + strconv.Itoa(int(sigType)))
}
// checkReader wraps an io.Reader from a LiteralData packet. When it sees EOF
// it closes the ReadCloser from any SymmetricallyEncrypted packet to trigger
// MDC checks.
type checkReader struct {
md *MessageDetails
}
func (cr checkReader) Read(buf []byte) (n int, err error) {
n, err = cr.md.LiteralData.Body.Read(buf)
if err == io.EOF {
mdcErr := cr.md.decrypted.Close()
if mdcErr != nil {
err = mdcErr
}
}
return
}
// signatureCheckReader wraps an io.Reader from a LiteralData packet and hashes
// the data as it is read. When it sees an EOF from the underlying io.Reader
// it parses and checks a trailing Signature packet and triggers any MDC checks.
type signatureCheckReader struct {
packets *packet.Reader
h, wrappedHash hash.Hash
md *MessageDetails
}
func (scr *signatureCheckReader) Read(buf []byte) (n int, err error) {
n, err = scr.md.LiteralData.Body.Read(buf)
scr.wrappedHash.Write(buf[:n])
if err == io.EOF {
var p packet.Packet
p, scr.md.SignatureError = scr.packets.Next()
if scr.md.SignatureError != nil {
return
}
var ok bool
if scr.md.Signature, ok = p.(*packet.Signature); ok {
var err error
if fingerprint := scr.md.Signature.IssuerFingerprint; fingerprint != nil {
if !hmac.Equal(fingerprint, scr.md.SignedBy.PublicKey.Fingerprint[:]) {
err = errors.StructuralError("bad key fingerprint")
}
}
if err == nil {
err = scr.md.SignedBy.PublicKey.VerifySignature(scr.h, scr.md.Signature)
}
scr.md.SignatureError = err
} else if scr.md.SignatureV3, ok = p.(*packet.SignatureV3); ok {
scr.md.SignatureError = scr.md.SignedBy.PublicKey.VerifySignatureV3(scr.h, scr.md.SignatureV3)
} else {
scr.md.SignatureError = errors.StructuralError("LiteralData not followed by Signature")
return
}
// The SymmetricallyEncrypted packet, if any, might have an
// unsigned hash of its own. In order to check this we need to
// close that Reader.
if scr.md.decrypted != nil {
mdcErr := scr.md.decrypted.Close()
if mdcErr != nil {
err = mdcErr
}
}
}
return
}
// CheckDetachedSignature takes a signed file and a detached signature and
// returns the signer if the signature is valid. If the signer isn't known,
// ErrUnknownIssuer is returned.
func CheckDetachedSignature(keyring KeyRing, signed, signature io.Reader) (signer *Entity, err error) {
signer, _, err = checkDetachedSignature(keyring, signed, signature)
return signer, err
}
func checkDetachedSignature(keyring KeyRing, signed, signature io.Reader) (signer *Entity, issuer *uint64, err error) {
var issuerKeyId uint64
var issuerFingerprint []byte
var hashFunc crypto.Hash
var sigType packet.SignatureType
var keys []Key
var p packet.Packet
packets := packet.NewReader(signature)
for {
p, err = packets.Next()
if err == io.EOF {
return nil, nil, errors.ErrUnknownIssuer
}
if err != nil {
return nil, nil, err
}
switch sig := p.(type) {
case *packet.Signature:
if sig.IssuerKeyId == nil {
return nil, nil, errors.StructuralError("signature doesn't have an issuer")
}
issuerKeyId = *sig.IssuerKeyId
hashFunc = sig.Hash
sigType = sig.SigType
issuerFingerprint = sig.IssuerFingerprint
case *packet.SignatureV3:
issuerKeyId = sig.IssuerKeyId
hashFunc = sig.Hash
sigType = sig.SigType
default:
return nil, nil, errors.StructuralError("non signature packet found")
}
keys = keyring.KeysByIdUsage(issuerKeyId, issuerFingerprint, packet.KeyFlagSign)
if len(keys) > 0 {
break
}
}
if len(keys) == 0 {
panic("unreachable")
}
h, wrappedHash, err := hashForSignature(hashFunc, sigType)
if err != nil {
return nil, nil, err
}
if _, err := io.Copy(wrappedHash, signed); err != nil && err != io.EOF {
return nil, nil, err
}
for _, key := range keys {
switch sig := p.(type) {
case *packet.Signature:
err = key.PublicKey.VerifySignature(h, sig)
case *packet.SignatureV3:
err = key.PublicKey.VerifySignatureV3(h, sig)
default:
panic("unreachable")
}
if err == nil {
return key.Entity, &issuerKeyId, nil
}
}
return nil, nil, err
}
// CheckArmoredDetachedSignature performs the same actions as
// CheckDetachedSignature but expects the signature to be armored.
func CheckArmoredDetachedSignature(keyring KeyRing, signed, signature io.Reader) (signer *Entity, err error) {
signer, _, err = checkArmoredDetachedSignature(keyring, signed, signature)
return signer, err
}
func checkArmoredDetachedSignature(keyring KeyRing, signed, signature io.Reader) (signer *Entity, issuer *uint64, err error) {
body, err := readArmored(signature, SignatureType)
if err != nil {
return
}
return checkDetachedSignature(keyring, signed, body)
}

326
vendor/github.com/keybase/go-crypto/openpgp/s2k/s2k.go generated vendored Normal file
View file

@ -0,0 +1,326 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package s2k implements the various OpenPGP string-to-key transforms as
// specified in RFC 4800 section 3.7.1.
package s2k // import "github.com/keybase/go-crypto/openpgp/s2k"
import (
"crypto"
"hash"
"io"
"strconv"
"github.com/keybase/go-crypto/openpgp/errors"
)
// Config collects configuration parameters for s2k key-stretching
// transformatioms. A nil *Config is valid and results in all default
// values. Currently, Config is used only by the Serialize function in
// this package.
type Config struct {
// Hash is the default hash function to be used. If
// nil, SHA1 is used.
Hash crypto.Hash
// S2KCount is only used for symmetric encryption. It
// determines the strength of the passphrase stretching when
// the said passphrase is hashed to produce a key. S2KCount
// should be between 1024 and 65011712, inclusive. If Config
// is nil or S2KCount is 0, the value 65536 used. Not all
// values in the above range can be represented. S2KCount will
// be rounded up to the next representable value if it cannot
// be encoded exactly. When set, it is strongly encrouraged to
// use a value that is at least 65536. See RFC 4880 Section
// 3.7.1.3.
S2KCount int
}
func (c *Config) hash() crypto.Hash {
if c == nil || uint(c.Hash) == 0 {
// SHA1 is the historical default in this package.
return crypto.SHA1
}
return c.Hash
}
func (c *Config) encodedCount() uint8 {
if c == nil || c.S2KCount == 0 {
return 96 // The common case. Correspoding to 65536
}
i := c.S2KCount
switch {
// Behave like GPG. Should we make 65536 the lowest value used?
case i < 1024:
i = 1024
case i > 65011712:
i = 65011712
}
return encodeCount(i)
}
// encodeCount converts an iterative "count" in the range 1024 to
// 65011712, inclusive, to an encoded count. The return value is the
// octet that is actually stored in the GPG file. encodeCount panics
// if i is not in the above range (encodedCount above takes care to
// pass i in the correct range). See RFC 4880 Section 3.7.7.1.
func encodeCount(i int) uint8 {
if i < 1024 || i > 65011712 {
panic("count arg i outside the required range")
}
for encoded := 0; encoded < 256; encoded++ {
count := decodeCount(uint8(encoded))
if count >= i {
return uint8(encoded)
}
}
return 255
}
// decodeCount returns the s2k mode 3 iterative "count" corresponding to
// the encoded octet c.
func decodeCount(c uint8) int {
return (16 + int(c&15)) << (uint32(c>>4) + 6)
}
// Simple writes to out the result of computing the Simple S2K function (RFC
// 4880, section 3.7.1.1) using the given hash and input passphrase.
func Simple(out []byte, h hash.Hash, in []byte) {
Salted(out, h, in, nil)
}
var zero [1]byte
// Salted writes to out the result of computing the Salted S2K function (RFC
// 4880, section 3.7.1.2) using the given hash, input passphrase and salt.
func Salted(out []byte, h hash.Hash, in []byte, salt []byte) {
done := 0
var digest []byte
for i := 0; done < len(out); i++ {
h.Reset()
for j := 0; j < i; j++ {
h.Write(zero[:])
}
h.Write(salt)
h.Write(in)
digest = h.Sum(digest[:0])
n := copy(out[done:], digest)
done += n
}
}
// Iterated writes to out the result of computing the Iterated and Salted S2K
// function (RFC 4880, section 3.7.1.3) using the given hash, input passphrase,
// salt and iteration count.
func Iterated(out []byte, h hash.Hash, in []byte, salt []byte, count int) {
combined := make([]byte, len(in)+len(salt))
copy(combined, salt)
copy(combined[len(salt):], in)
if count < len(combined) {
count = len(combined)
}
done := 0
var digest []byte
for i := 0; done < len(out); i++ {
h.Reset()
for j := 0; j < i; j++ {
h.Write(zero[:])
}
written := 0
for written < count {
if written+len(combined) > count {
todo := count - written
h.Write(combined[:todo])
written = count
} else {
h.Write(combined)
written += len(combined)
}
}
digest = h.Sum(digest[:0])
n := copy(out[done:], digest)
done += n
}
}
func parseGNUExtensions(r io.Reader) (f func(out, in []byte), err error) {
var buf [9]byte
// A three-byte string identifier
_, err = io.ReadFull(r, buf[:3])
if err != nil {
return
}
gnuExt := string(buf[:3])
if gnuExt != "GNU" {
return nil, errors.UnsupportedError("Malformed GNU extension: " + gnuExt)
}
_, err = io.ReadFull(r, buf[:1])
if err != nil {
return
}
gnuExtType := int(buf[0])
switch gnuExtType {
case 1:
return nil, nil
case 2:
// Read a serial number, which is prefixed by a 1-byte length.
// The maximum length is 16.
var lenBuf [1]byte
_, err = io.ReadFull(r, lenBuf[:])
if err != nil {
return
}
maxLen := 16
ivLen := int(lenBuf[0])
if ivLen > maxLen {
ivLen = maxLen
}
ivBuf := make([]byte, ivLen)
// For now we simply discard the IV
_, err = io.ReadFull(r, ivBuf)
if err != nil {
return
}
return nil, nil
default:
return nil, errors.UnsupportedError("unknown S2K GNU protection mode: " + strconv.Itoa(int(gnuExtType)))
}
}
// Parse reads a binary specification for a string-to-key transformation from r
// and returns a function which performs that transform.
func Parse(r io.Reader) (f func(out, in []byte), err error) {
var buf [9]byte
_, err = io.ReadFull(r, buf[:2])
if err != nil {
return
}
// GNU Extensions; handle them before we try to look for a hash, which won't
// be needed in most cases anyway.
if buf[0] == 101 {
return parseGNUExtensions(r)
}
hash, ok := HashIdToHash(buf[1])
if !ok {
return nil, errors.UnsupportedError("hash for S2K function: " + strconv.Itoa(int(buf[1])))
}
if !hash.Available() {
return nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hash)))
}
h := hash.New()
switch buf[0] {
case 0:
f := func(out, in []byte) {
Simple(out, h, in)
}
return f, nil
case 1:
_, err = io.ReadFull(r, buf[:8])
if err != nil {
return
}
f := func(out, in []byte) {
Salted(out, h, in, buf[:8])
}
return f, nil
case 3:
_, err = io.ReadFull(r, buf[:9])
if err != nil {
return
}
count := decodeCount(buf[8])
f := func(out, in []byte) {
Iterated(out, h, in, buf[:8], count)
}
return f, nil
}
return nil, errors.UnsupportedError("S2K function")
}
// Serialize salts and stretches the given passphrase and writes the
// resulting key into key. It also serializes an S2K descriptor to
// w. The key stretching can be configured with c, which may be
// nil. In that case, sensible defaults will be used.
func Serialize(w io.Writer, key []byte, rand io.Reader, passphrase []byte, c *Config) error {
var buf [11]byte
buf[0] = 3 /* iterated and salted */
buf[1], _ = HashToHashId(c.hash())
salt := buf[2:10]
if _, err := io.ReadFull(rand, salt); err != nil {
return err
}
encodedCount := c.encodedCount()
count := decodeCount(encodedCount)
buf[10] = encodedCount
if _, err := w.Write(buf[:]); err != nil {
return err
}
Iterated(key, c.hash().New(), passphrase, salt, count)
return nil
}
// hashToHashIdMapping contains pairs relating OpenPGP's hash identifier with
// Go's crypto.Hash type. See RFC 4880, section 9.4.
var hashToHashIdMapping = []struct {
id byte
hash crypto.Hash
name string
}{
{1, crypto.MD5, "MD5"},
{2, crypto.SHA1, "SHA1"},
{3, crypto.RIPEMD160, "RIPEMD160"},
{8, crypto.SHA256, "SHA256"},
{9, crypto.SHA384, "SHA384"},
{10, crypto.SHA512, "SHA512"},
{11, crypto.SHA224, "SHA224"},
}
// HashIdToHash returns a crypto.Hash which corresponds to the given OpenPGP
// hash id.
func HashIdToHash(id byte) (h crypto.Hash, ok bool) {
for _, m := range hashToHashIdMapping {
if m.id == id {
return m.hash, true
}
}
return 0, false
}
// HashIdToString returns the name of the hash function corresponding to the
// given OpenPGP hash id, or panics if id is unknown.
func HashIdToString(id byte) (name string, ok bool) {
for _, m := range hashToHashIdMapping {
if m.id == id {
return m.name, true
}
}
return "", false
}
// HashIdToHash returns an OpenPGP hash id which corresponds the given Hash.
func HashToHashId(h crypto.Hash) (id byte, ok bool) {
for _, m := range hashToHashIdMapping {
if m.hash == h {
return m.id, true
}
}
return 0, false
}

View file

@ -0,0 +1,135 @@
diff --git a/openpgp/read.go b/openpgp/read.go
index a6cecc5..0c9397b 100644
--- a/openpgp/read.go
+++ b/openpgp/read.go
@@ -56,8 +56,9 @@ type MessageDetails struct {
// been consumed. Once EOF has been seen, the following fields are
// valid. (An authentication code failure is reported as a
// SignatureError error when reading from UnverifiedBody.)
- SignatureError error // nil if the signature is good.
- Signature *packet.Signature // the signature packet itself.
+ SignatureError error // nil if the signature is good.
+ Signature *packet.Signature // the signature packet itself, if v4 (default)
+ SignatureV3 *packet.SignatureV3 // the signature packet if it is a v2 or v3 signature
decrypted io.ReadCloser
}
@@ -334,13 +335,15 @@ func (scr *signatureCheckReader) Read(buf []byte) (n int, err error) {
}
var ok bool
- if scr.md.Signature, ok = p.(*packet.Signature); !ok {
+ if scr.md.Signature, ok = p.(*packet.Signature); ok {
+ scr.md.SignatureError = scr.md.SignedBy.PublicKey.VerifySignature(scr.h, scr.md.Signature)
+ } else if scr.md.SignatureV3, ok = p.(*packet.SignatureV3); ok {
+ scr.md.SignatureError = scr.md.SignedBy.PublicKey.VerifySignatureV3(scr.h, scr.md.SignatureV3)
+ } else {
scr.md.SignatureError = errors.StructuralError("LiteralData not followed by Signature")
return
}
- scr.md.SignatureError = scr.md.SignedBy.PublicKey.VerifySignature(scr.h, scr.md.Signature)
-
// The SymmetricallyEncrypted packet, if any, might have an
// unsigned hash of its own. In order to check this we need to
// close that Reader.
diff --git a/openpgp/read_test.go b/openpgp/read_test.go
index 52f942c..abe8d7b 100644
--- a/openpgp/read_test.go
+++ b/openpgp/read_test.go
@@ -13,6 +13,7 @@ import (
"strings"
"testing"
+ "golang.org/x/crypto/openpgp/armor"
"golang.org/x/crypto/openpgp/errors"
)
@@ -411,6 +412,50 @@ func TestIssue11504(t *testing.T) {
testReadMessageError(t, "9303000130303030303030303030983002303030303030030000000130")
}
+// TestSignatureV3Message tests the verification of V3 signature, generated
+// with a modern V4-style key. Some people have their clients set to generate
+// V3 signatures, so it's useful to be able to verify them.
+func TestSignatureV3Message(t *testing.T) {
+ sig, err := armor.Decode(strings.NewReader(signedMessageV3))
+ if err != nil {
+ t.Error(err)
+ return
+ }
+ key, err := ReadArmoredKeyRing(strings.NewReader(keyV4forVerifyingSignedMessageV3))
+ if err != nil {
+ t.Error(err)
+ return
+ }
+ md, err := ReadMessage(sig.Body, key, nil, nil)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ _, err = ioutil.ReadAll(md.UnverifiedBody)
+ if err != nil {
+ t.Error(err)
+ return
+ }
+
+ // We'll see a sig error here after reading in the UnverifiedBody above,
+ // if there was one to see.
+ if err = md.SignatureError; err != nil {
+ t.Error(err)
+ return
+ }
+
+ if md.SignatureV3 == nil {
+ t.Errorf("No available signature after checking signature")
+ return
+ }
+ if md.Signature != nil {
+ t.Errorf("Did not expect a signature V4 back")
+ return
+ }
+ return
+}
+
const testKey1KeyId = 0xA34D7E18C20C31BB
const testKey3KeyId = 0x338934250CCC0360
@@ -504,3 +549,36 @@ const unknownHashFunctionHex = `8a00000040040001990006050253863c24000a09103b4fe6
const missingHashFunctionHex = `8a00000040040001030006050253863c24000a09103b4fe6acc0b21f32ffff0101010101010101010101010101010101010101010101010101010101010101010101010101`
const campbellQuine = `a0b001000300fcffa0b001000d00f2ff000300fcffa0b001000d00f2ff8270a01c00000500faff8270a01c00000500faff000500faff001400ebff8270a01c00000500faff000500faff001400ebff428821c400001400ebff428821c400001400ebff428821c400001400ebff428821c400001400ebff428821c400000000ffff000000ffff000b00f4ff428821c400000000ffff000000ffff000b00f4ff0233214c40000100feff000233214c40000100feff0000`
+
+const keyV4forVerifyingSignedMessageV3 = `-----BEGIN PGP PUBLIC KEY BLOCK-----
+Comment: GPGTools - https://gpgtools.org
+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RZia
+-----END PGP PUBLIC KEY BLOCK-----
+`
+
+const signedMessageV3 = `-----BEGIN PGP MESSAGE-----
+Comment: GPGTools - https://gpgtools.org
+
+owGbwMvMwMVYWXlhlrhb9GXG03JJDKF/MtxDMjKLFYAoUaEktbhEITe1uDgxPVWP
+q5NhKjMrWAVcC9evD8z/bF/uWNjqtk/X3y5/38XGRQHm/57rrDRYuGnTw597Xqka
+uM3137/hH3Os+Jf2dc0fXOITKwJvXJvecPVs0ta+Vg7ZO1MLn8w58Xx+6L58mbka
+DGHyU9yTueZE8D+QF/Tz28Y78dqtF56R1VPn9Xw4uJqrWYdd7b3vIZ1V6R4Nh05d
+iT57d/OhWwA=
+=hG7R
+-----END PGP MESSAGE-----
+`

495
vendor/github.com/keybase/go-crypto/openpgp/write.go generated vendored Normal file
View file

@ -0,0 +1,495 @@
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package openpgp
import (
"crypto"
"hash"
"io"
"strconv"
"time"
"github.com/keybase/go-crypto/openpgp/armor"
"github.com/keybase/go-crypto/openpgp/errors"
"github.com/keybase/go-crypto/openpgp/packet"
"github.com/keybase/go-crypto/openpgp/s2k"
)
// DetachSign signs message with the private key from signer (which must
// already have been decrypted) and writes the signature to w.
// If config is nil, sensible defaults will be used.
func DetachSign(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) error {
return detachSign(w, signer, message, packet.SigTypeBinary, config)
}
// ArmoredDetachSign signs message with the private key from signer (which
// must already have been decrypted) and writes an armored signature to w.
// If config is nil, sensible defaults will be used.
func ArmoredDetachSign(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) (err error) {
return armoredDetachSign(w, signer, message, packet.SigTypeBinary, config)
}
// DetachSignText signs message (after canonicalising the line endings) with
// the private key from signer (which must already have been decrypted) and
// writes the signature to w.
// If config is nil, sensible defaults will be used.
func DetachSignText(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) error {
return detachSign(w, signer, message, packet.SigTypeText, config)
}
// ArmoredDetachSignText signs message (after canonicalising the line endings)
// with the private key from signer (which must already have been decrypted)
// and writes an armored signature to w.
// If config is nil, sensible defaults will be used.
func ArmoredDetachSignText(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) error {
return armoredDetachSign(w, signer, message, packet.SigTypeText, config)
}
func armoredDetachSign(w io.Writer, signer *Entity, message io.Reader, sigType packet.SignatureType, config *packet.Config) (err error) {
out, err := armor.Encode(w, SignatureType, nil)
if err != nil {
return
}
err = detachSign(out, signer, message, sigType, config)
if err != nil {
return
}
return out.Close()
}
// SignWithSigner signs the message of type sigType with s and writes the
// signature to w.
// If config is nil, sensible defaults will be used.
func SignWithSigner(s packet.Signer, w io.Writer, message io.Reader, sigType packet.SignatureType, config *packet.Config) (err error) {
keyId := s.KeyId()
sig := new(packet.Signature)
sig.SigType = sigType
sig.PubKeyAlgo = s.PublicKeyAlgo()
sig.Hash = config.Hash()
sig.CreationTime = config.Now()
sig.IssuerKeyId = &keyId
s.Reset()
wrapped := s.(hash.Hash)
if sigType == packet.SigTypeText {
wrapped = NewCanonicalTextHash(s)
}
io.Copy(wrapped, message)
err = sig.Sign(s, nil, config)
if err != nil {
return
}
err = sig.Serialize(w)
return
}
func detachSign(w io.Writer, signer *Entity, message io.Reader, sigType packet.SignatureType, config *packet.Config) (err error) {
signerSubkey, ok := signer.signingKey(config.Now())
if !ok {
err = errors.InvalidArgumentError("no valid signing keys")
return
}
if signerSubkey.PrivateKey == nil {
return errors.InvalidArgumentError("signing key doesn't have a private key")
}
if signerSubkey.PrivateKey.Encrypted {
return errors.InvalidArgumentError("signing key is encrypted")
}
sig := new(packet.Signature)
sig.SigType = sigType
sig.PubKeyAlgo = signerSubkey.PrivateKey.PubKeyAlgo
sig.Hash = config.Hash()
sig.CreationTime = config.Now()
sig.IssuerKeyId = &signerSubkey.PrivateKey.KeyId
h, wrappedHash, err := hashForSignature(sig.Hash, sig.SigType)
if err != nil {
return
}
io.Copy(wrappedHash, message)
err = sig.Sign(h, signerSubkey.PrivateKey, config)
if err != nil {
return
}
return sig.Serialize(w)
}
// FileHints contains metadata about encrypted files. This metadata is, itself,
// encrypted.
type FileHints struct {
// IsBinary can be set to hint that the contents are binary data.
IsBinary bool
// FileName hints at the name of the file that should be written. It's
// truncated to 255 bytes if longer. It may be empty to suggest that the
// file should not be written to disk. It may be equal to "_CONSOLE" to
// suggest the data should not be written to disk.
FileName string
// ModTime contains the modification time of the file, or the zero time if not applicable.
ModTime time.Time
}
// SymmetricallyEncrypt acts like gpg -c: it encrypts a file with a passphrase.
// The resulting WriteCloser must be closed after the contents of the file have
// been written.
// If config is nil, sensible defaults will be used.
func SymmetricallyEncrypt(ciphertext io.Writer, passphrase []byte, hints *FileHints, config *packet.Config) (plaintext io.WriteCloser, err error) {
if hints == nil {
hints = &FileHints{}
}
key, err := packet.SerializeSymmetricKeyEncrypted(ciphertext, passphrase, config)
if err != nil {
return
}
w, err := packet.SerializeSymmetricallyEncrypted(ciphertext, config.Cipher(), key, config)
if err != nil {
return
}
literaldata := w
if algo := config.Compression(); algo != packet.CompressionNone {
var compConfig *packet.CompressionConfig
if config != nil {
compConfig = config.CompressionConfig
}
literaldata, err = packet.SerializeCompressed(w, algo, compConfig)
if err != nil {
return
}
}
var epochSeconds uint32
if !hints.ModTime.IsZero() {
epochSeconds = uint32(hints.ModTime.Unix())
}
return packet.SerializeLiteral(literaldata, hints.IsBinary, hints.FileName, epochSeconds)
}
// intersectPreferences mutates and returns a prefix of a that contains only
// the values in the intersection of a and b. The order of a is preserved.
func intersectPreferences(a []uint8, b []uint8) (intersection []uint8) {
var j int
for _, v := range a {
for _, v2 := range b {
if v == v2 {
a[j] = v
j++
break
}
}
}
return a[:j]
}
func hashToHashId(h crypto.Hash) uint8 {
v, ok := s2k.HashToHashId(h)
if !ok {
panic("tried to convert unknown hash")
}
return v
}
// Encrypt encrypts a message to a number of recipients and, optionally, signs
// it. hints contains optional information, that is also encrypted, that aids
// the recipients in processing the message. The resulting WriteCloser must
// be closed after the contents of the file have been written.
// If config is nil, sensible defaults will be used.
func Encrypt(ciphertext io.Writer, to []*Entity, signed *Entity, hints *FileHints, config *packet.Config) (plaintext io.WriteCloser, err error) {
var signer *packet.PrivateKey
if signed != nil {
signKey, ok := signed.signingKey(config.Now())
if !ok {
return nil, errors.InvalidArgumentError("no valid signing keys")
}
signer = signKey.PrivateKey
if signer == nil {
return nil, errors.InvalidArgumentError("no private key in signing key")
}
if signer.Encrypted {
return nil, errors.InvalidArgumentError("signing key must be decrypted")
}
}
// These are the possible ciphers that we'll use for the message.
candidateCiphers := []uint8{
uint8(packet.CipherAES128),
uint8(packet.CipherAES256),
uint8(packet.CipherCAST5),
}
// These are the possible hash functions that we'll use for the signature.
candidateHashes := []uint8{
hashToHashId(crypto.SHA256),
hashToHashId(crypto.SHA512),
hashToHashId(crypto.SHA1),
hashToHashId(crypto.RIPEMD160),
}
// If no preferences were specified, assume something safe and reasonable.
defaultCiphers := []uint8{
uint8(packet.CipherAES128),
uint8(packet.CipherAES192),
uint8(packet.CipherAES256),
uint8(packet.CipherCAST5),
}
defaultHashes := []uint8{
hashToHashId(crypto.SHA256),
hashToHashId(crypto.SHA512),
hashToHashId(crypto.RIPEMD160),
}
encryptKeys := make([]Key, len(to))
for i := range to {
var ok bool
encryptKeys[i], ok = to[i].encryptionKey(config.Now())
if !ok {
return nil, errors.InvalidArgumentError("cannot encrypt a message to key id " + strconv.FormatUint(to[i].PrimaryKey.KeyId, 16) + " because it has no encryption keys")
}
sig := to[i].primaryIdentity().SelfSignature
preferredSymmetric := sig.PreferredSymmetric
if len(preferredSymmetric) == 0 {
preferredSymmetric = defaultCiphers
}
preferredHashes := sig.PreferredHash
if len(preferredHashes) == 0 {
preferredHashes = defaultHashes
}
candidateCiphers = intersectPreferences(candidateCiphers, preferredSymmetric)
candidateHashes = intersectPreferences(candidateHashes, preferredHashes)
}
if len(candidateCiphers) == 0 {
return nil, errors.InvalidArgumentError("cannot encrypt because recipient set shares no common ciphers")
}
if len(candidateHashes) == 0 {
return nil, errors.InvalidArgumentError("cannot encrypt because recipient set shares no common hashes")
}
cipher := packet.CipherFunction(candidateCiphers[0])
// If the cipher specifed by config is a candidate, we'll use that.
configuredCipher := config.Cipher()
for _, c := range candidateCiphers {
cipherFunc := packet.CipherFunction(c)
if cipherFunc == configuredCipher {
cipher = cipherFunc
break
}
}
var hash crypto.Hash
for _, hashId := range candidateHashes {
if h, ok := s2k.HashIdToHash(hashId); ok && h.Available() {
hash = h
break
}
}
// If the hash specified by config is a candidate, we'll use that.
if configuredHash := config.Hash(); configuredHash.Available() {
for _, hashId := range candidateHashes {
if h, ok := s2k.HashIdToHash(hashId); ok && h == configuredHash {
hash = h
break
}
}
}
if hash == 0 {
hashId := candidateHashes[0]
name, ok := s2k.HashIdToString(hashId)
if !ok {
name = "#" + strconv.Itoa(int(hashId))
}
return nil, errors.InvalidArgumentError("cannot encrypt because no candidate hash functions are compiled in. (Wanted " + name + " in this case.)")
}
symKey := make([]byte, cipher.KeySize())
if _, err := io.ReadFull(config.Random(), symKey); err != nil {
return nil, err
}
for _, key := range encryptKeys {
if err := packet.SerializeEncryptedKey(ciphertext, key.PublicKey, cipher, symKey, config); err != nil {
return nil, err
}
}
encryptedData, err := packet.SerializeSymmetricallyEncrypted(ciphertext, cipher, symKey, config)
if err != nil {
return
}
if signer != nil {
ops := &packet.OnePassSignature{
SigType: packet.SigTypeBinary,
Hash: hash,
PubKeyAlgo: signer.PubKeyAlgo,
KeyId: signer.KeyId,
IsLast: true,
}
if err := ops.Serialize(encryptedData); err != nil {
return nil, err
}
}
if hints == nil {
hints = &FileHints{}
}
w := encryptedData
if signer != nil {
// If we need to write a signature packet after the literal
// data then we need to stop literalData from closing
// encryptedData.
w = noOpCloser{encryptedData}
}
var epochSeconds uint32
if !hints.ModTime.IsZero() {
epochSeconds = uint32(hints.ModTime.Unix())
}
literalData, err := packet.SerializeLiteral(w, hints.IsBinary, hints.FileName, epochSeconds)
if err != nil {
return nil, err
}
if signer != nil {
return signatureWriter{encryptedData, literalData, hash, hash.New(), signer, config}, nil
}
return literalData, nil
}
// signatureWriter hashes the contents of a message while passing it along to
// literalData. When closed, it closes literalData, writes a signature packet
// to encryptedData and then also closes encryptedData.
type signatureWriter struct {
encryptedData io.WriteCloser
literalData io.WriteCloser
hashType crypto.Hash
h hash.Hash
signer *packet.PrivateKey
config *packet.Config
}
func (s signatureWriter) Write(data []byte) (int, error) {
s.h.Write(data)
return s.literalData.Write(data)
}
func (s signatureWriter) Close() error {
sig := &packet.Signature{
SigType: packet.SigTypeBinary,
PubKeyAlgo: s.signer.PubKeyAlgo,
Hash: s.hashType,
CreationTime: s.config.Now(),
IssuerKeyId: &s.signer.KeyId,
}
if err := sig.Sign(s.h, s.signer, s.config); err != nil {
return err
}
if err := s.literalData.Close(); err != nil {
return err
}
if err := sig.Serialize(s.encryptedData); err != nil {
return err
}
return s.encryptedData.Close()
}
// noOpCloser is like an ioutil.NopCloser, but for an io.Writer.
// TODO: we have two of these in OpenPGP packages alone. This probably needs
// to be promoted somewhere more common.
type noOpCloser struct {
w io.Writer
}
func (c noOpCloser) Write(data []byte) (n int, err error) {
return c.w.Write(data)
}
func (c noOpCloser) Close() error {
return nil
}
// AttachedSign is like openpgp.Encrypt (as in p.crypto/openpgp/write.go), but
// don't encrypt at all, just sign the literal unencrypted data.
// Unfortunately we need to duplicate some code here that's already
// in write.go
func AttachedSign(out io.WriteCloser, signed Entity, hints *FileHints,
config *packet.Config) (in io.WriteCloser, err error) {
if hints == nil {
hints = &FileHints{}
}
if config == nil {
config = &packet.Config{}
}
var signer *packet.PrivateKey
signKey, ok := signed.signingKey(config.Now())
if !ok {
err = errors.InvalidArgumentError("no valid signing keys")
return
}
signer = signKey.PrivateKey
if signer == nil {
err = errors.InvalidArgumentError("no valid signing keys")
return
}
if signer.Encrypted {
err = errors.InvalidArgumentError("signing key must be decrypted")
return
}
hasher := crypto.SHA512
ops := &packet.OnePassSignature{
SigType: packet.SigTypeBinary,
Hash: hasher,
PubKeyAlgo: signer.PubKeyAlgo,
KeyId: signer.KeyId,
IsLast: true,
}
if err = ops.Serialize(out); err != nil {
return
}
var epochSeconds uint32
if !hints.ModTime.IsZero() {
epochSeconds = uint32(hints.ModTime.Unix())
}
// We don't want the literal serializer to closer the output stream
// since we're going to need to write to it when we finish up the
// signature stuff.
in, err = packet.SerializeLiteral(noOpCloser{out}, hints.IsBinary, hints.FileName, epochSeconds)
if err != nil {
return
}
// If we need to write a signature packet after the literal
// data then we need to stop literalData from closing
// encryptedData.
in = signatureWriter{out, in, hasher, hasher.New(), signer, config}
return
}

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vendor/github.com/keybase/go-crypto/rsa/pkcs1v15.go generated vendored Normal file
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package rsa
import (
"crypto"
"crypto/subtle"
"errors"
"io"
"math/big"
)
// This file implements encryption and decryption using PKCS#1 v1.5 padding.
// PKCS1v15DecrypterOpts is for passing options to PKCS#1 v1.5 decryption using
// the crypto.Decrypter interface.
type PKCS1v15DecryptOptions struct {
// SessionKeyLen is the length of the session key that is being
// decrypted. If not zero, then a padding error during decryption will
// cause a random plaintext of this length to be returned rather than
// an error. These alternatives happen in constant time.
SessionKeyLen int
}
// EncryptPKCS1v15 encrypts the given message with RSA and the padding scheme from PKCS#1 v1.5.
// The message must be no longer than the length of the public modulus minus 11 bytes.
//
// The rand parameter is used as a source of entropy to ensure that encrypting
// the same message twice doesn't result in the same ciphertext.
//
// WARNING: use of this function to encrypt plaintexts other than session keys
// is dangerous. Use RSA OAEP in new protocols.
func EncryptPKCS1v15(rand io.Reader, pub *PublicKey, msg []byte) (out []byte, err error) {
if err := checkPub(pub); err != nil {
return nil, err
}
k := (pub.N.BitLen() + 7) / 8
if len(msg) > k-11 {
err = ErrMessageTooLong
return
}
// EM = 0x00 || 0x02 || PS || 0x00 || M
em := make([]byte, k)
em[1] = 2
ps, mm := em[2:len(em)-len(msg)-1], em[len(em)-len(msg):]
err = nonZeroRandomBytes(ps, rand)
if err != nil {
return
}
em[len(em)-len(msg)-1] = 0
copy(mm, msg)
m := new(big.Int).SetBytes(em)
c := encrypt(new(big.Int), pub, m)
copyWithLeftPad(em, c.Bytes())
out = em
return
}
// DecryptPKCS1v15 decrypts a plaintext using RSA and the padding scheme from PKCS#1 v1.5.
// If rand != nil, it uses RSA blinding to avoid timing side-channel attacks.
//
// Note that whether this function returns an error or not discloses secret
// information. If an attacker can cause this function to run repeatedly and
// learn whether each instance returned an error then they can decrypt and
// forge signatures as if they had the private key. See
// DecryptPKCS1v15SessionKey for a way of solving this problem.
func DecryptPKCS1v15(rand io.Reader, priv *PrivateKey, ciphertext []byte) (out []byte, err error) {
if err := checkPub(&priv.PublicKey); err != nil {
return nil, err
}
valid, out, index, err := decryptPKCS1v15(rand, priv, ciphertext)
if err != nil {
return
}
if valid == 0 {
return nil, ErrDecryption
}
out = out[index:]
return
}
// DecryptPKCS1v15SessionKey decrypts a session key using RSA and the padding scheme from PKCS#1 v1.5.
// If rand != nil, it uses RSA blinding to avoid timing side-channel attacks.
// It returns an error if the ciphertext is the wrong length or if the
// ciphertext is greater than the public modulus. Otherwise, no error is
// returned. If the padding is valid, the resulting plaintext message is copied
// into key. Otherwise, key is unchanged. These alternatives occur in constant
// time. It is intended that the user of this function generate a random
// session key beforehand and continue the protocol with the resulting value.
// This will remove any possibility that an attacker can learn any information
// about the plaintext.
// See ``Chosen Ciphertext Attacks Against Protocols Based on the RSA
// Encryption Standard PKCS #1'', Daniel Bleichenbacher, Advances in Cryptology
// (Crypto '98).
//
// Note that if the session key is too small then it may be possible for an
// attacker to brute-force it. If they can do that then they can learn whether
// a random value was used (because it'll be different for the same ciphertext)
// and thus whether the padding was correct. This defeats the point of this
// function. Using at least a 16-byte key will protect against this attack.
func DecryptPKCS1v15SessionKey(rand io.Reader, priv *PrivateKey, ciphertext []byte, key []byte) (err error) {
if err := checkPub(&priv.PublicKey); err != nil {
return err
}
k := (priv.N.BitLen() + 7) / 8
if k-(len(key)+3+8) < 0 {
return ErrDecryption
}
valid, em, index, err := decryptPKCS1v15(rand, priv, ciphertext)
if err != nil {
return
}
if len(em) != k {
// This should be impossible because decryptPKCS1v15 always
// returns the full slice.
return ErrDecryption
}
valid &= subtle.ConstantTimeEq(int32(len(em)-index), int32(len(key)))
subtle.ConstantTimeCopy(valid, key, em[len(em)-len(key):])
return
}
// decryptPKCS1v15 decrypts ciphertext using priv and blinds the operation if
// rand is not nil. It returns one or zero in valid that indicates whether the
// plaintext was correctly structured. In either case, the plaintext is
// returned in em so that it may be read independently of whether it was valid
// in order to maintain constant memory access patterns. If the plaintext was
// valid then index contains the index of the original message in em.
func decryptPKCS1v15(rand io.Reader, priv *PrivateKey, ciphertext []byte) (valid int, em []byte, index int, err error) {
k := (priv.N.BitLen() + 7) / 8
if k < 11 {
err = ErrDecryption
return
}
c := new(big.Int).SetBytes(ciphertext)
m, err := decrypt(rand, priv, c)
if err != nil {
return
}
em = leftPad(m.Bytes(), k)
firstByteIsZero := subtle.ConstantTimeByteEq(em[0], 0)
secondByteIsTwo := subtle.ConstantTimeByteEq(em[1], 2)
// The remainder of the plaintext must be a string of non-zero random
// octets, followed by a 0, followed by the message.
// lookingForIndex: 1 iff we are still looking for the zero.
// index: the offset of the first zero byte.
lookingForIndex := 1
for i := 2; i < len(em); i++ {
equals0 := subtle.ConstantTimeByteEq(em[i], 0)
index = subtle.ConstantTimeSelect(lookingForIndex&equals0, i, index)
lookingForIndex = subtle.ConstantTimeSelect(equals0, 0, lookingForIndex)
}
// The PS padding must be at least 8 bytes long, and it starts two
// bytes into em.
validPS := subtle.ConstantTimeLessOrEq(2+8, index)
valid = firstByteIsZero & secondByteIsTwo & (^lookingForIndex & 1) & validPS
index = subtle.ConstantTimeSelect(valid, index+1, 0)
return valid, em, index, nil
}
// nonZeroRandomBytes fills the given slice with non-zero random octets.
func nonZeroRandomBytes(s []byte, rand io.Reader) (err error) {
_, err = io.ReadFull(rand, s)
if err != nil {
return
}
for i := 0; i < len(s); i++ {
for s[i] == 0 {
_, err = io.ReadFull(rand, s[i:i+1])
if err != nil {
return
}
// In tests, the PRNG may return all zeros so we do
// this to break the loop.
s[i] ^= 0x42
}
}
return
}
// These are ASN1 DER structures:
// DigestInfo ::= SEQUENCE {
// digestAlgorithm AlgorithmIdentifier,
// digest OCTET STRING
// }
// For performance, we don't use the generic ASN1 encoder. Rather, we
// precompute a prefix of the digest value that makes a valid ASN1 DER string
// with the correct contents.
var hashPrefixes = map[crypto.Hash][]byte{
crypto.MD5: {0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, 0x05, 0x00, 0x04, 0x10},
crypto.SHA1: {0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14},
crypto.SHA224: {0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1c},
crypto.SHA256: {0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20},
crypto.SHA384: {0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30},
crypto.SHA512: {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40},
crypto.MD5SHA1: {}, // A special TLS case which doesn't use an ASN1 prefix.
crypto.RIPEMD160: {0x30, 0x20, 0x30, 0x08, 0x06, 0x06, 0x28, 0xcf, 0x06, 0x03, 0x00, 0x31, 0x04, 0x14},
}
// SignPKCS1v15 calculates the signature of hashed using RSASSA-PKCS1-V1_5-SIGN from RSA PKCS#1 v1.5.
// Note that hashed must be the result of hashing the input message using the
// given hash function. If hash is zero, hashed is signed directly. This isn't
// advisable except for interoperability.
//
// If rand is not nil then RSA blinding will be used to avoid timing side-channel attacks.
//
// This function is deterministic. Thus, if the set of possible messages is
// small, an attacker may be able to build a map from messages to signatures
// and identify the signed messages. As ever, signatures provide authenticity,
// not confidentiality.
func SignPKCS1v15(rand io.Reader, priv *PrivateKey, hash crypto.Hash, hashed []byte) (s []byte, err error) {
hashLen, prefix, err := pkcs1v15HashInfo(hash, len(hashed))
if err != nil {
return
}
tLen := len(prefix) + hashLen
k := (priv.N.BitLen() + 7) / 8
if k < tLen+11 {
return nil, ErrMessageTooLong
}
// EM = 0x00 || 0x01 || PS || 0x00 || T
em := make([]byte, k)
em[1] = 1
for i := 2; i < k-tLen-1; i++ {
em[i] = 0xff
}
copy(em[k-tLen:k-hashLen], prefix)
copy(em[k-hashLen:k], hashed)
m := new(big.Int).SetBytes(em)
c, err := decryptAndCheck(rand, priv, m)
if err != nil {
return
}
copyWithLeftPad(em, c.Bytes())
s = em
return
}
// VerifyPKCS1v15 verifies an RSA PKCS#1 v1.5 signature.
// hashed is the result of hashing the input message using the given hash
// function and sig is the signature. A valid signature is indicated by
// returning a nil error. If hash is zero then hashed is used directly. This
// isn't advisable except for interoperability.
func VerifyPKCS1v15(pub *PublicKey, hash crypto.Hash, hashed []byte, sig []byte) (err error) {
hashLen, prefix, err := pkcs1v15HashInfo(hash, len(hashed))
if err != nil {
return
}
tLen := len(prefix) + hashLen
k := (pub.N.BitLen() + 7) / 8
if k < tLen+11 {
err = ErrVerification
return
}
c := new(big.Int).SetBytes(sig)
m := encrypt(new(big.Int), pub, c)
em := leftPad(m.Bytes(), k)
// EM = 0x00 || 0x01 || PS || 0x00 || T
ok := subtle.ConstantTimeByteEq(em[0], 0)
ok &= subtle.ConstantTimeByteEq(em[1], 1)
ok &= subtle.ConstantTimeCompare(em[k-hashLen:k], hashed)
ok &= subtle.ConstantTimeCompare(em[k-tLen:k-hashLen], prefix)
ok &= subtle.ConstantTimeByteEq(em[k-tLen-1], 0)
for i := 2; i < k-tLen-1; i++ {
ok &= subtle.ConstantTimeByteEq(em[i], 0xff)
}
if ok != 1 {
return ErrVerification
}
return nil
}
func pkcs1v15HashInfo(hash crypto.Hash, inLen int) (hashLen int, prefix []byte, err error) {
// Special case: crypto.Hash(0) is used to indicate that the data is
// signed directly.
if hash == 0 {
return inLen, nil, nil
}
hashLen = hash.Size()
if inLen != hashLen {
return 0, nil, errors.New("crypto/rsa: input must be hashed message")
}
prefix, ok := hashPrefixes[hash]
if !ok {
return 0, nil, errors.New("crypto/rsa: unsupported hash function")
}
return
}
// copyWithLeftPad copies src to the end of dest, padding with zero bytes as
// needed.
func copyWithLeftPad(dest, src []byte) {
numPaddingBytes := len(dest) - len(src)
for i := 0; i < numPaddingBytes; i++ {
dest[i] = 0
}
copy(dest[numPaddingBytes:], src)
}

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vendor/github.com/keybase/go-crypto/rsa/pss.go generated vendored Normal file
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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package rsa
// This file implements the PSS signature scheme [1].
//
// [1] http://www.rsa.com/rsalabs/pkcs/files/h11300-wp-pkcs-1v2-2-rsa-cryptography-standard.pdf
import (
"bytes"
"crypto"
"errors"
"hash"
"io"
"math/big"
)
func emsaPSSEncode(mHash []byte, emBits int, salt []byte, hash hash.Hash) ([]byte, error) {
// See [1], section 9.1.1
hLen := hash.Size()
sLen := len(salt)
emLen := (emBits + 7) / 8
// 1. If the length of M is greater than the input limitation for the
// hash function (2^61 - 1 octets for SHA-1), output "message too
// long" and stop.
//
// 2. Let mHash = Hash(M), an octet string of length hLen.
if len(mHash) != hLen {
return nil, errors.New("crypto/rsa: input must be hashed message")
}
// 3. If emLen < hLen + sLen + 2, output "encoding error" and stop.
if emLen < hLen+sLen+2 {
return nil, errors.New("crypto/rsa: encoding error")
}
em := make([]byte, emLen)
db := em[:emLen-sLen-hLen-2+1+sLen]
h := em[emLen-sLen-hLen-2+1+sLen : emLen-1]
// 4. Generate a random octet string salt of length sLen; if sLen = 0,
// then salt is the empty string.
//
// 5. Let
// M' = (0x)00 00 00 00 00 00 00 00 || mHash || salt;
//
// M' is an octet string of length 8 + hLen + sLen with eight
// initial zero octets.
//
// 6. Let H = Hash(M'), an octet string of length hLen.
var prefix [8]byte
hash.Write(prefix[:])
hash.Write(mHash)
hash.Write(salt)
h = hash.Sum(h[:0])
hash.Reset()
// 7. Generate an octet string PS consisting of emLen - sLen - hLen - 2
// zero octets. The length of PS may be 0.
//
// 8. Let DB = PS || 0x01 || salt; DB is an octet string of length
// emLen - hLen - 1.
db[emLen-sLen-hLen-2] = 0x01
copy(db[emLen-sLen-hLen-1:], salt)
// 9. Let dbMask = MGF(H, emLen - hLen - 1).
//
// 10. Let maskedDB = DB \xor dbMask.
mgf1XOR(db, hash, h)
// 11. Set the leftmost 8 * emLen - emBits bits of the leftmost octet in
// maskedDB to zero.
db[0] &= (0xFF >> uint(8*emLen-emBits))
// 12. Let EM = maskedDB || H || 0xbc.
em[emLen-1] = 0xBC
// 13. Output EM.
return em, nil
}
func emsaPSSVerify(mHash, em []byte, emBits, sLen int, hash hash.Hash) error {
// 1. If the length of M is greater than the input limitation for the
// hash function (2^61 - 1 octets for SHA-1), output "inconsistent"
// and stop.
//
// 2. Let mHash = Hash(M), an octet string of length hLen.
hLen := hash.Size()
if hLen != len(mHash) {
return ErrVerification
}
// 3. If emLen < hLen + sLen + 2, output "inconsistent" and stop.
emLen := (emBits + 7) / 8
if emLen < hLen+sLen+2 {
return ErrVerification
}
// 4. If the rightmost octet of EM does not have hexadecimal value
// 0xbc, output "inconsistent" and stop.
if em[len(em)-1] != 0xBC {
return ErrVerification
}
// 5. Let maskedDB be the leftmost emLen - hLen - 1 octets of EM, and
// let H be the next hLen octets.
db := em[:emLen-hLen-1]
h := em[emLen-hLen-1 : len(em)-1]
// 6. If the leftmost 8 * emLen - emBits bits of the leftmost octet in
// maskedDB are not all equal to zero, output "inconsistent" and
// stop.
if em[0]&(0xFF<<uint(8-(8*emLen-emBits))) != 0 {
return ErrVerification
}
// 7. Let dbMask = MGF(H, emLen - hLen - 1).
//
// 8. Let DB = maskedDB \xor dbMask.
mgf1XOR(db, hash, h)
// 9. Set the leftmost 8 * emLen - emBits bits of the leftmost octet in DB
// to zero.
db[0] &= (0xFF >> uint(8*emLen-emBits))
if sLen == PSSSaltLengthAuto {
FindSaltLength:
for sLen = emLen - (hLen + 2); sLen >= 0; sLen-- {
switch db[emLen-hLen-sLen-2] {
case 1:
break FindSaltLength
case 0:
continue
default:
return ErrVerification
}
}
if sLen < 0 {
return ErrVerification
}
} else {
// 10. If the emLen - hLen - sLen - 2 leftmost octets of DB are not zero
// or if the octet at position emLen - hLen - sLen - 1 (the leftmost
// position is "position 1") does not have hexadecimal value 0x01,
// output "inconsistent" and stop.
for _, e := range db[:emLen-hLen-sLen-2] {
if e != 0x00 {
return ErrVerification
}
}
if db[emLen-hLen-sLen-2] != 0x01 {
return ErrVerification
}
}
// 11. Let salt be the last sLen octets of DB.
salt := db[len(db)-sLen:]
// 12. Let
// M' = (0x)00 00 00 00 00 00 00 00 || mHash || salt ;
// M' is an octet string of length 8 + hLen + sLen with eight
// initial zero octets.
//
// 13. Let H' = Hash(M'), an octet string of length hLen.
var prefix [8]byte
hash.Write(prefix[:])
hash.Write(mHash)
hash.Write(salt)
h0 := hash.Sum(nil)
// 14. If H = H', output "consistent." Otherwise, output "inconsistent."
if !bytes.Equal(h0, h) {
return ErrVerification
}
return nil
}
// signPSSWithSalt calculates the signature of hashed using PSS [1] with specified salt.
// Note that hashed must be the result of hashing the input message using the
// given hash function. salt is a random sequence of bytes whose length will be
// later used to verify the signature.
func signPSSWithSalt(rand io.Reader, priv *PrivateKey, hash crypto.Hash, hashed, salt []byte) (s []byte, err error) {
nBits := priv.N.BitLen()
em, err := emsaPSSEncode(hashed, nBits-1, salt, hash.New())
if err != nil {
return
}
m := new(big.Int).SetBytes(em)
c, err := decryptAndCheck(rand, priv, m)
if err != nil {
return
}
s = make([]byte, (nBits+7)/8)
copyWithLeftPad(s, c.Bytes())
return
}
const (
// PSSSaltLengthAuto causes the salt in a PSS signature to be as large
// as possible when signing, and to be auto-detected when verifying.
PSSSaltLengthAuto = 0
// PSSSaltLengthEqualsHash causes the salt length to equal the length
// of the hash used in the signature.
PSSSaltLengthEqualsHash = -1
)
// PSSOptions contains options for creating and verifying PSS signatures.
type PSSOptions struct {
// SaltLength controls the length of the salt used in the PSS
// signature. It can either be a number of bytes, or one of the special
// PSSSaltLength constants.
SaltLength int
// Hash, if not zero, overrides the hash function passed to SignPSS.
// This is the only way to specify the hash function when using the
// crypto.Signer interface.
Hash crypto.Hash
}
// HashFunc returns pssOpts.Hash so that PSSOptions implements
// crypto.SignerOpts.
func (pssOpts *PSSOptions) HashFunc() crypto.Hash {
return pssOpts.Hash
}
func (opts *PSSOptions) saltLength() int {
if opts == nil {
return PSSSaltLengthAuto
}
return opts.SaltLength
}
// SignPSS calculates the signature of hashed using RSASSA-PSS [1].
// Note that hashed must be the result of hashing the input message using the
// given hash function. The opts argument may be nil, in which case sensible
// defaults are used.
func SignPSS(rand io.Reader, priv *PrivateKey, hash crypto.Hash, hashed []byte, opts *PSSOptions) (s []byte, err error) {
saltLength := opts.saltLength()
switch saltLength {
case PSSSaltLengthAuto:
saltLength = (priv.N.BitLen()+7)/8 - 2 - hash.Size()
case PSSSaltLengthEqualsHash:
saltLength = hash.Size()
}
if opts != nil && opts.Hash != 0 {
hash = opts.Hash
}
salt := make([]byte, saltLength)
if _, err = io.ReadFull(rand, salt); err != nil {
return
}
return signPSSWithSalt(rand, priv, hash, hashed, salt)
}
// VerifyPSS verifies a PSS signature.
// hashed is the result of hashing the input message using the given hash
// function and sig is the signature. A valid signature is indicated by
// returning a nil error. The opts argument may be nil, in which case sensible
// defaults are used.
func VerifyPSS(pub *PublicKey, hash crypto.Hash, hashed []byte, sig []byte, opts *PSSOptions) error {
return verifyPSS(pub, hash, hashed, sig, opts.saltLength())
}
// verifyPSS verifies a PSS signature with the given salt length.
func verifyPSS(pub *PublicKey, hash crypto.Hash, hashed []byte, sig []byte, saltLen int) error {
nBits := pub.N.BitLen()
if len(sig) != (nBits+7)/8 {
return ErrVerification
}
s := new(big.Int).SetBytes(sig)
m := encrypt(new(big.Int), pub, s)
emBits := nBits - 1
emLen := (emBits + 7) / 8
if emLen < len(m.Bytes()) {
return ErrVerification
}
em := make([]byte, emLen)
copyWithLeftPad(em, m.Bytes())
if saltLen == PSSSaltLengthEqualsHash {
saltLen = hash.Size()
}
return emsaPSSVerify(hashed, em, emBits, saltLen, hash.New())
}

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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package rsa implements RSA encryption as specified in PKCS#1.
//
// RSA is a single, fundamental operation that is used in this package to
// implement either public-key encryption or public-key signatures.
//
// The original specification for encryption and signatures with RSA is PKCS#1
// and the terms "RSA encryption" and "RSA signatures" by default refer to
// PKCS#1 version 1.5. However, that specification has flaws and new designs
// should use version two, usually called by just OAEP and PSS, where
// possible.
//
// Two sets of interfaces are included in this package. When a more abstract
// interface isn't neccessary, there are functions for encrypting/decrypting
// with v1.5/OAEP and signing/verifying with v1.5/PSS. If one needs to abstract
// over the public-key primitive, the PrivateKey struct implements the
// Decrypter and Signer interfaces from the crypto package.
package rsa
import (
"crypto"
"crypto/rand"
"crypto/subtle"
"errors"
"hash"
"io"
"math/big"
)
var bigZero = big.NewInt(0)
var bigOne = big.NewInt(1)
// A PublicKey represents the public part of an RSA key.
type PublicKey struct {
N *big.Int // modulus
E int64 // public exponent
}
// OAEPOptions is an interface for passing options to OAEP decryption using the
// crypto.Decrypter interface.
type OAEPOptions struct {
// Hash is the hash function that will be used when generating the mask.
Hash crypto.Hash
// Label is an arbitrary byte string that must be equal to the value
// used when encrypting.
Label []byte
}
var (
errPublicModulus = errors.New("crypto/rsa: missing public modulus")
errPublicExponentSmall = errors.New("crypto/rsa: public exponent too small")
errPublicExponentLarge = errors.New("crypto/rsa: public exponent too large")
)
// checkPub sanity checks the public key before we use it.
// We require pub.E to fit into a 32-bit integer so that we
// do not have different behavior depending on whether
// int is 32 or 64 bits. See also
// http://www.imperialviolet.org/2012/03/16/rsae.html.
func checkPub(pub *PublicKey) error {
if pub.N == nil {
return errPublicModulus
}
if pub.E < 2 {
return errPublicExponentSmall
}
if pub.E > 1<<63-1 {
return errPublicExponentLarge
}
return nil
}
// A PrivateKey represents an RSA key
type PrivateKey struct {
PublicKey // public part.
D *big.Int // private exponent
Primes []*big.Int // prime factors of N, has >= 2 elements.
// Precomputed contains precomputed values that speed up private
// operations, if available.
Precomputed PrecomputedValues
}
// Public returns the public key corresponding to priv.
func (priv *PrivateKey) Public() crypto.PublicKey {
return &priv.PublicKey
}
// Sign signs msg with priv, reading randomness from rand. If opts is a
// *PSSOptions then the PSS algorithm will be used, otherwise PKCS#1 v1.5 will
// be used. This method is intended to support keys where the private part is
// kept in, for example, a hardware module. Common uses should use the Sign*
// functions in this package.
func (priv *PrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) ([]byte, error) {
if pssOpts, ok := opts.(*PSSOptions); ok {
return SignPSS(rand, priv, pssOpts.Hash, msg, pssOpts)
}
return SignPKCS1v15(rand, priv, opts.HashFunc(), msg)
}
// Decrypt decrypts ciphertext with priv. If opts is nil or of type
// *PKCS1v15DecryptOptions then PKCS#1 v1.5 decryption is performed. Otherwise
// opts must have type *OAEPOptions and OAEP decryption is done.
func (priv *PrivateKey) Decrypt(rand io.Reader, ciphertext []byte, opts crypto.DecrypterOpts) (plaintext []byte, err error) {
if opts == nil {
return DecryptPKCS1v15(rand, priv, ciphertext)
}
switch opts := opts.(type) {
case *OAEPOptions:
return DecryptOAEP(opts.Hash.New(), rand, priv, ciphertext, opts.Label)
case *PKCS1v15DecryptOptions:
if l := opts.SessionKeyLen; l > 0 {
plaintext = make([]byte, l)
if _, err := io.ReadFull(rand, plaintext); err != nil {
return nil, err
}
if err := DecryptPKCS1v15SessionKey(rand, priv, ciphertext, plaintext); err != nil {
return nil, err
}
return plaintext, nil
} else {
return DecryptPKCS1v15(rand, priv, ciphertext)
}
default:
return nil, errors.New("crypto/rsa: invalid options for Decrypt")
}
}
type PrecomputedValues struct {
Dp, Dq *big.Int // D mod (P-1) (or mod Q-1)
Qinv *big.Int // Q^-1 mod P
// CRTValues is used for the 3rd and subsequent primes. Due to a
// historical accident, the CRT for the first two primes is handled
// differently in PKCS#1 and interoperability is sufficiently
// important that we mirror this.
CRTValues []CRTValue
}
// CRTValue contains the precomputed Chinese remainder theorem values.
type CRTValue struct {
Exp *big.Int // D mod (prime-1).
Coeff *big.Int // R·Coeff ≡ 1 mod Prime.
R *big.Int // product of primes prior to this (inc p and q).
}
// Validate performs basic sanity checks on the key.
// It returns nil if the key is valid, or else an error describing a problem.
func (priv *PrivateKey) Validate() error {
if err := checkPub(&priv.PublicKey); err != nil {
return err
}
// Check that Πprimes == n.
modulus := new(big.Int).Set(bigOne)
for _, prime := range priv.Primes {
// Any primes ≤ 1 will cause divide-by-zero panics later.
if prime.Cmp(bigOne) <= 0 {
return errors.New("crypto/rsa: invalid prime value")
}
modulus.Mul(modulus, prime)
}
if modulus.Cmp(priv.N) != 0 {
return errors.New("crypto/rsa: invalid modulus")
}
// Check that de ≡ 1 mod p-1, for each prime.
// This implies that e is coprime to each p-1 as e has a multiplicative
// inverse. Therefore e is coprime to lcm(p-1,q-1,r-1,...) =
// exponent(/n). It also implies that a^de ≡ a mod p as a^(p-1) ≡ 1
// mod p. Thus a^de ≡ a mod n for all a coprime to n, as required.
congruence := new(big.Int)
de := new(big.Int).SetInt64(int64(priv.E))
de.Mul(de, priv.D)
for _, prime := range priv.Primes {
pminus1 := new(big.Int).Sub(prime, bigOne)
congruence.Mod(de, pminus1)
if congruence.Cmp(bigOne) != 0 {
return errors.New("crypto/rsa: invalid exponents")
}
}
return nil
}
// GenerateKey generates an RSA keypair of the given bit size using the
// random source random (for example, crypto/rand.Reader).
func GenerateKey(random io.Reader, bits int) (priv *PrivateKey, err error) {
return GenerateMultiPrimeKey(random, 2, bits)
}
// GenerateMultiPrimeKey generates a multi-prime RSA keypair of the given bit
// size and the given random source, as suggested in [1]. Although the public
// keys are compatible (actually, indistinguishable) from the 2-prime case,
// the private keys are not. Thus it may not be possible to export multi-prime
// private keys in certain formats or to subsequently import them into other
// code.
//
// Table 1 in [2] suggests maximum numbers of primes for a given size.
//
// [1] US patent 4405829 (1972, expired)
// [2] http://www.cacr.math.uwaterloo.ca/techreports/2006/cacr2006-16.pdf
func GenerateMultiPrimeKey(random io.Reader, nprimes int, bits int) (priv *PrivateKey, err error) {
priv = new(PrivateKey)
priv.E = 65537
if nprimes < 2 {
return nil, errors.New("crypto/rsa: GenerateMultiPrimeKey: nprimes must be >= 2")
}
primes := make([]*big.Int, nprimes)
NextSetOfPrimes:
for {
todo := bits
// crypto/rand should set the top two bits in each prime.
// Thus each prime has the form
// p_i = 2^bitlen(p_i) × 0.11... (in base 2).
// And the product is:
// P = 2^todo × α
// where α is the product of nprimes numbers of the form 0.11...
//
// If α < 1/2 (which can happen for nprimes > 2), we need to
// shift todo to compensate for lost bits: the mean value of 0.11...
// is 7/8, so todo + shift - nprimes * log2(7/8) ~= bits - 1/2
// will give good results.
if nprimes >= 7 {
todo += (nprimes - 2) / 5
}
for i := 0; i < nprimes; i++ {
primes[i], err = rand.Prime(random, todo/(nprimes-i))
if err != nil {
return nil, err
}
todo -= primes[i].BitLen()
}
// Make sure that primes is pairwise unequal.
for i, prime := range primes {
for j := 0; j < i; j++ {
if prime.Cmp(primes[j]) == 0 {
continue NextSetOfPrimes
}
}
}
n := new(big.Int).Set(bigOne)
totient := new(big.Int).Set(bigOne)
pminus1 := new(big.Int)
for _, prime := range primes {
n.Mul(n, prime)
pminus1.Sub(prime, bigOne)
totient.Mul(totient, pminus1)
}
if n.BitLen() != bits {
// This should never happen for nprimes == 2 because
// crypto/rand should set the top two bits in each prime.
// For nprimes > 2 we hope it does not happen often.
continue NextSetOfPrimes
}
g := new(big.Int)
priv.D = new(big.Int)
y := new(big.Int)
e := big.NewInt(int64(priv.E))
g.GCD(priv.D, y, e, totient)
if g.Cmp(bigOne) == 0 {
if priv.D.Sign() < 0 {
priv.D.Add(priv.D, totient)
}
priv.Primes = primes
priv.N = n
break
}
}
priv.Precompute()
return
}
// incCounter increments a four byte, big-endian counter.
func incCounter(c *[4]byte) {
if c[3]++; c[3] != 0 {
return
}
if c[2]++; c[2] != 0 {
return
}
if c[1]++; c[1] != 0 {
return
}
c[0]++
}
// mgf1XOR XORs the bytes in out with a mask generated using the MGF1 function
// specified in PKCS#1 v2.1.
func mgf1XOR(out []byte, hash hash.Hash, seed []byte) {
var counter [4]byte
var digest []byte
done := 0
for done < len(out) {
hash.Write(seed)
hash.Write(counter[0:4])
digest = hash.Sum(digest[:0])
hash.Reset()
for i := 0; i < len(digest) && done < len(out); i++ {
out[done] ^= digest[i]
done++
}
incCounter(&counter)
}
}
// ErrMessageTooLong is returned when attempting to encrypt a message which is
// too large for the size of the public key.
var ErrMessageTooLong = errors.New("crypto/rsa: message too long for RSA public key size")
func encrypt(c *big.Int, pub *PublicKey, m *big.Int) *big.Int {
e := big.NewInt(int64(pub.E))
c.Exp(m, e, pub.N)
return c
}
// EncryptOAEP encrypts the given message with RSA-OAEP.
//
// OAEP is parameterised by a hash function that is used as a random oracle.
// Encryption and decryption of a given message must use the same hash function
// and sha256.New() is a reasonable choice.
//
// The random parameter is used as a source of entropy to ensure that
// encrypting the same message twice doesn't result in the same ciphertext.
//
// The label parameter may contain arbitrary data that will not be encrypted,
// but which gives important context to the message. For example, if a given
// public key is used to decrypt two types of messages then distinct label
// values could be used to ensure that a ciphertext for one purpose cannot be
// used for another by an attacker. If not required it can be empty.
//
// The message must be no longer than the length of the public modulus less
// twice the hash length plus 2.
func EncryptOAEP(hash hash.Hash, random io.Reader, pub *PublicKey, msg []byte, label []byte) (out []byte, err error) {
if err := checkPub(pub); err != nil {
return nil, err
}
hash.Reset()
k := (pub.N.BitLen() + 7) / 8
if len(msg) > k-2*hash.Size()-2 {
err = ErrMessageTooLong
return
}
hash.Write(label)
lHash := hash.Sum(nil)
hash.Reset()
em := make([]byte, k)
seed := em[1 : 1+hash.Size()]
db := em[1+hash.Size():]
copy(db[0:hash.Size()], lHash)
db[len(db)-len(msg)-1] = 1
copy(db[len(db)-len(msg):], msg)
_, err = io.ReadFull(random, seed)
if err != nil {
return
}
mgf1XOR(db, hash, seed)
mgf1XOR(seed, hash, db)
m := new(big.Int)
m.SetBytes(em)
c := encrypt(new(big.Int), pub, m)
out = c.Bytes()
if len(out) < k {
// If the output is too small, we need to left-pad with zeros.
t := make([]byte, k)
copy(t[k-len(out):], out)
out = t
}
return
}
// ErrDecryption represents a failure to decrypt a message.
// It is deliberately vague to avoid adaptive attacks.
var ErrDecryption = errors.New("crypto/rsa: decryption error")
// ErrVerification represents a failure to verify a signature.
// It is deliberately vague to avoid adaptive attacks.
var ErrVerification = errors.New("crypto/rsa: verification error")
// modInverse returns ia, the inverse of a in the multiplicative group of prime
// order n. It requires that a be a member of the group (i.e. less than n).
func modInverse(a, n *big.Int) (ia *big.Int, ok bool) {
g := new(big.Int)
x := new(big.Int)
y := new(big.Int)
g.GCD(x, y, a, n)
if g.Cmp(bigOne) != 0 {
// In this case, a and n aren't coprime and we cannot calculate
// the inverse. This happens because the values of n are nearly
// prime (being the product of two primes) rather than truly
// prime.
return
}
if x.Cmp(bigOne) < 0 {
// 0 is not the multiplicative inverse of any element so, if x
// < 1, then x is negative.
x.Add(x, n)
}
return x, true
}
// Precompute performs some calculations that speed up private key operations
// in the future.
func (priv *PrivateKey) Precompute() {
if priv.Precomputed.Dp != nil {
return
}
priv.Precomputed.Dp = new(big.Int).Sub(priv.Primes[0], bigOne)
priv.Precomputed.Dp.Mod(priv.D, priv.Precomputed.Dp)
priv.Precomputed.Dq = new(big.Int).Sub(priv.Primes[1], bigOne)
priv.Precomputed.Dq.Mod(priv.D, priv.Precomputed.Dq)
priv.Precomputed.Qinv = new(big.Int).ModInverse(priv.Primes[1], priv.Primes[0])
r := new(big.Int).Mul(priv.Primes[0], priv.Primes[1])
priv.Precomputed.CRTValues = make([]CRTValue, len(priv.Primes)-2)
for i := 2; i < len(priv.Primes); i++ {
prime := priv.Primes[i]
values := &priv.Precomputed.CRTValues[i-2]
values.Exp = new(big.Int).Sub(prime, bigOne)
values.Exp.Mod(priv.D, values.Exp)
values.R = new(big.Int).Set(r)
values.Coeff = new(big.Int).ModInverse(r, prime)
r.Mul(r, prime)
}
}
// decrypt performs an RSA decryption, resulting in a plaintext integer. If a
// random source is given, RSA blinding is used.
func decrypt(random io.Reader, priv *PrivateKey, c *big.Int) (m *big.Int, err error) {
// TODO(agl): can we get away with reusing blinds?
if c.Cmp(priv.N) > 0 {
err = ErrDecryption
return
}
var ir *big.Int
if random != nil {
// Blinding enabled. Blinding involves multiplying c by r^e.
// Then the decryption operation performs (m^e * r^e)^d mod n
// which equals mr mod n. The factor of r can then be removed
// by multiplying by the multiplicative inverse of r.
var r *big.Int
for {
r, err = rand.Int(random, priv.N)
if err != nil {
return
}
if r.Cmp(bigZero) == 0 {
r = bigOne
}
var ok bool
ir, ok = modInverse(r, priv.N)
if ok {
break
}
}
bigE := big.NewInt(int64(priv.E))
rpowe := new(big.Int).Exp(r, bigE, priv.N)
cCopy := new(big.Int).Set(c)
cCopy.Mul(cCopy, rpowe)
cCopy.Mod(cCopy, priv.N)
c = cCopy
}
if priv.Precomputed.Dp == nil {
m = new(big.Int).Exp(c, priv.D, priv.N)
} else {
// We have the precalculated values needed for the CRT.
m = new(big.Int).Exp(c, priv.Precomputed.Dp, priv.Primes[0])
m2 := new(big.Int).Exp(c, priv.Precomputed.Dq, priv.Primes[1])
m.Sub(m, m2)
if m.Sign() < 0 {
m.Add(m, priv.Primes[0])
}
m.Mul(m, priv.Precomputed.Qinv)
m.Mod(m, priv.Primes[0])
m.Mul(m, priv.Primes[1])
m.Add(m, m2)
for i, values := range priv.Precomputed.CRTValues {
prime := priv.Primes[2+i]
m2.Exp(c, values.Exp, prime)
m2.Sub(m2, m)
m2.Mul(m2, values.Coeff)
m2.Mod(m2, prime)
if m2.Sign() < 0 {
m2.Add(m2, prime)
}
m2.Mul(m2, values.R)
m.Add(m, m2)
}
}
if ir != nil {
// Unblind.
m.Mul(m, ir)
m.Mod(m, priv.N)
}
return
}
func decryptAndCheck(random io.Reader, priv *PrivateKey, c *big.Int) (m *big.Int, err error) {
m, err = decrypt(random, priv, c)
if err != nil {
return nil, err
}
// In order to defend against errors in the CRT computation, m^e is
// calculated, which should match the original ciphertext.
check := encrypt(new(big.Int), &priv.PublicKey, m)
if c.Cmp(check) != 0 {
return nil, errors.New("rsa: internal error")
}
return m, nil
}
// DecryptOAEP decrypts ciphertext using RSA-OAEP.
// OAEP is parameterised by a hash function that is used as a random oracle.
// Encryption and decryption of a given message must use the same hash function
// and sha256.New() is a reasonable choice.
//
// The random parameter, if not nil, is used to blind the private-key operation
// and avoid timing side-channel attacks. Blinding is purely internal to this
// function the random data need not match that used when encrypting.
//
// The label parameter must match the value given when encrypting. See
// EncryptOAEP for details.
func DecryptOAEP(hash hash.Hash, random io.Reader, priv *PrivateKey, ciphertext []byte, label []byte) (msg []byte, err error) {
if err := checkPub(&priv.PublicKey); err != nil {
return nil, err
}
k := (priv.N.BitLen() + 7) / 8
if len(ciphertext) > k ||
k < hash.Size()*2+2 {
err = ErrDecryption
return
}
c := new(big.Int).SetBytes(ciphertext)
m, err := decrypt(random, priv, c)
if err != nil {
return
}
hash.Write(label)
lHash := hash.Sum(nil)
hash.Reset()
// Converting the plaintext number to bytes will strip any
// leading zeros so we may have to left pad. We do this unconditionally
// to avoid leaking timing information. (Although we still probably
// leak the number of leading zeros. It's not clear that we can do
// anything about this.)
em := leftPad(m.Bytes(), k)
firstByteIsZero := subtle.ConstantTimeByteEq(em[0], 0)
seed := em[1 : hash.Size()+1]
db := em[hash.Size()+1:]
mgf1XOR(seed, hash, db)
mgf1XOR(db, hash, seed)
lHash2 := db[0:hash.Size()]
// We have to validate the plaintext in constant time in order to avoid
// attacks like: J. Manger. A Chosen Ciphertext Attack on RSA Optimal
// Asymmetric Encryption Padding (OAEP) as Standardized in PKCS #1
// v2.0. In J. Kilian, editor, Advances in Cryptology.
lHash2Good := subtle.ConstantTimeCompare(lHash, lHash2)
// The remainder of the plaintext must be zero or more 0x00, followed
// by 0x01, followed by the message.
// lookingForIndex: 1 iff we are still looking for the 0x01
// index: the offset of the first 0x01 byte
// invalid: 1 iff we saw a non-zero byte before the 0x01.
var lookingForIndex, index, invalid int
lookingForIndex = 1
rest := db[hash.Size():]
for i := 0; i < len(rest); i++ {
equals0 := subtle.ConstantTimeByteEq(rest[i], 0)
equals1 := subtle.ConstantTimeByteEq(rest[i], 1)
index = subtle.ConstantTimeSelect(lookingForIndex&equals1, i, index)
lookingForIndex = subtle.ConstantTimeSelect(equals1, 0, lookingForIndex)
invalid = subtle.ConstantTimeSelect(lookingForIndex&^equals0, 1, invalid)
}
if firstByteIsZero&lHash2Good&^invalid&^lookingForIndex != 1 {
err = ErrDecryption
return
}
msg = rest[index+1:]
return
}
// leftPad returns a new slice of length size. The contents of input are right
// aligned in the new slice.
func leftPad(input []byte, size int) (out []byte) {
n := len(input)
if n > size {
n = size
}
out = make([]byte, size)
copy(out[len(out)-n:], input)
return
}