Upgrade to golang-jwt 3.2.2 (#16590)

* Upgrade to golang-jwt 3.2.2

Upgrade to the latest version of golang-jwt

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Forcibly replace the 3.2.1 version of golang-jwt/jwt and increase minimum Go version

Using go.mod we can forcibly replace the 3.2.1 version used by goth to 3.2.2.

Further given golang-jwt/jwts stated policy of only supporting supported go versions
we should just raise our minimal version of go to 1.16 for 1.16 as by time of release
1.15 will be out of support.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* update minimal go required

Signed-off-by: Andrew Thornton <art27@cantab.net>

* update config.yaml

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: 6543 <6543@obermui.de>

vendor/github.com/golang-jwt/jwt/ed25519_utils.go

@@ -0,0 +1,64 @@
+package jwt
+
+import (
+	"crypto"
+	"crypto/ed25519"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+)
+
+var (
+	ErrNotEdPrivateKey = errors.New("Key is not a valid Ed25519 private key")
+	ErrNotEdPublicKey  = errors.New("Key is not a valid Ed25519 public key")
+)
+
+// Parse PEM-encoded Edwards curve private key
+func ParseEdPrivateKeyFromPEM(key []byte) (crypto.PrivateKey, error) {
+	var err error
+
+	// Parse PEM block
+	var block *pem.Block
+	if block, _ = pem.Decode(key); block == nil {
+		return nil, ErrKeyMustBePEMEncoded
+	}
+
+	// Parse the key
+	var parsedKey interface{}
+	if parsedKey, err = x509.ParsePKCS8PrivateKey(block.Bytes); err != nil {
+		return nil, err
+	}
+
+	var pkey ed25519.PrivateKey
+	var ok bool
+	if pkey, ok = parsedKey.(ed25519.PrivateKey); !ok {
+		return nil, ErrNotEdPrivateKey
+	}
+
+	return pkey, nil
+}
+
+// Parse PEM-encoded Edwards curve public key
+func ParseEdPublicKeyFromPEM(key []byte) (crypto.PublicKey, error) {
+	var err error
+
+	// Parse PEM block
+	var block *pem.Block
+	if block, _ = pem.Decode(key); block == nil {
+		return nil, ErrKeyMustBePEMEncoded
+	}
+
+	// Parse the key
+	var parsedKey interface{}
+	if parsedKey, err = x509.ParsePKIXPublicKey(block.Bytes); err != nil {
+		return nil, err
+	}
+
+	var pkey ed25519.PublicKey
+	var ok bool
+	if pkey, ok = parsedKey.(ed25519.PublicKey); !ok {
+		return nil, ErrNotEdPublicKey
+	}
+
+	return pkey, nil
+}