#12897 - add mastodon provider (#13293)

* added mastodon provider to oauth code

* changed go.mod and vendor/modules.txt to add updated goth

* vendored mastodon and new goth

* committing result of go mod tidy && go mod vendor

* added pic and mastodon to oauth models

* handled instance url

* applied lafriks suggestion

* Update web_src/js/index.js

Co-authored-by: techknowlogick <matti@mdranta.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: techknowlogick <matti@mdranta.net>

vendor/github.com/markbates/goth/providers/mastodon/mastodon.go

@@ -0,0 +1,185 @@
+// Package mastodon implements the OAuth2 protocol for authenticating users through Mastodon.
+// This package can be used as a reference implementation of an OAuth2 provider for Goth.
+package mastodon
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/markbates/goth"
+	"golang.org/x/oauth2"
+)
+
+// Mastodon.social is the flagship instance of mastodon
+var (
+	InstanceURL = "https://mastodon.social/"
+)
+
+// Provider is the implementation of `goth.Provider` for accessing Mastodon.
+type Provider struct {
+	ClientKey    string
+	Secret       string
+	CallbackURL  string
+	HTTPClient   *http.Client
+	config       *oauth2.Config
+	providerName string
+	authURL      string
+	tokenURL     string
+	profileURL   string
+}
+
+// New creates a new Mastodon provider and sets up important connection details.
+// You should always call `mastodon.New` to get a new provider.  Never try to
+// create one manually.
+func New(clientKey, secret, callbackURL string, scopes ...string) *Provider {
+	return NewCustomisedURL(clientKey, secret, callbackURL, InstanceURL, scopes...)
+}
+
+// NewCustomisedURL is similar to New(...) but can be used to set custom URLs to connect to
+func NewCustomisedURL(clientKey, secret, callbackURL, instanceURL string, scopes ...string) *Provider {
+	instanceURL = fmt.Sprintf("%s/", strings.TrimSuffix(instanceURL, "/"))
+	profileURL := fmt.Sprintf("%sapi/v1/accounts/verify_credentials", instanceURL)
+	authURL := fmt.Sprintf("%soauth/authorize", instanceURL)
+	tokenURL := fmt.Sprintf("%soauth/token", instanceURL)
+	p := &Provider{
+		ClientKey:    clientKey,
+		Secret:       secret,
+		CallbackURL:  callbackURL,
+		providerName: "mastodon",
+		profileURL:   profileURL,
+	}
+	p.config = newConfig(p, authURL, tokenURL, scopes)
+	return p
+}
+
+// Name is the name used to retrieve this provider later.
+func (p *Provider) Name() string {
+	return p.providerName
+}
+
+// SetName is to update the name of the provider (needed in case of multiple providers of 1 type)
+func (p *Provider) SetName(name string) {
+	p.providerName = name
+}
+
+func (p *Provider) Client() *http.Client {
+	return goth.HTTPClientWithFallBack(p.HTTPClient)
+}
+
+// Debug is a no-op for the Mastodon package.
+func (p *Provider) Debug(debug bool) {}
+
+// BeginAuth asks Mastodon for an authentication end-point.
+func (p *Provider) BeginAuth(state string) (goth.Session, error) {
+	return &Session{
+		AuthURL: p.config.AuthCodeURL(state),
+	}, nil
+}
+
+// FetchUser will go to Mastodon and access basic information about the user.
+func (p *Provider) FetchUser(session goth.Session) (goth.User, error) {
+	sess := session.(*Session)
+	user := goth.User{
+		AccessToken:  sess.AccessToken,
+		Provider:     p.Name(),
+		RefreshToken: sess.RefreshToken,
+		ExpiresAt:    sess.ExpiresAt,
+	}
+
+	if user.AccessToken == "" {
+		// data is not yet retrieved since accessToken is still empty
+		return user, fmt.Errorf("%s cannot get user information without accessToken", p.providerName)
+	}
+
+	req, err := http.NewRequest("GET", p.profileURL, nil)
+	if err != nil {
+		return user, err
+	}
+
+	req.Header.Add("Authorization", "Bearer "+sess.AccessToken)
+	response, err := p.Client().Do(req)
+	if err != nil {
+		return user, err
+	}
+	defer response.Body.Close()
+
+	if response.StatusCode != http.StatusOK {
+		return user, fmt.Errorf("%s responded with a %d trying to fetch user information", p.providerName, response.StatusCode)
+	}
+
+	bits, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		return user, err
+	}
+
+	err = json.NewDecoder(bytes.NewReader(bits)).Decode(&user.RawData)
+	if err != nil {
+		return user, err
+	}
+
+	err = userFromReader(bytes.NewReader(bits), &user)
+
+	return user, err
+}
+
+func newConfig(provider *Provider, authURL, tokenURL string, scopes []string) *oauth2.Config {
+	c := &oauth2.Config{
+		ClientID:     provider.ClientKey,
+		ClientSecret: provider.Secret,
+		RedirectURL:  provider.CallbackURL,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  authURL,
+			TokenURL: tokenURL,
+		},
+		Scopes: []string{},
+	}
+
+	if len(scopes) > 0 {
+		for _, scope := range scopes {
+			c.Scopes = append(c.Scopes, scope)
+		}
+	}
+	return c
+}
+
+func userFromReader(r io.Reader, user *goth.User) error {
+	u := struct {
+		Name      string `json:"display_name"`
+		NickName  string `json:"username"`
+		ID        string `json:"id"`
+		AvatarURL string `json:"avatar"`
+	}{}
+	err := json.NewDecoder(r).Decode(&u)
+	if err != nil {
+		return err
+	}
+	user.Name = u.Name
+	if len(user.Name) == 0 {
+		user.Name = u.NickName
+	}
+	user.NickName = u.NickName
+	user.UserID = u.ID
+	user.AvatarURL = u.AvatarURL
+	return nil
+}
+
+//RefreshTokenAvailable refresh token is provided by auth provider or not
+func (p *Provider) RefreshTokenAvailable() bool {
+	return true
+}
+
+//RefreshToken get new access token based on the refresh token
+func (p *Provider) RefreshToken(refreshToken string) (*oauth2.Token, error) {
+	token := &oauth2.Token{RefreshToken: refreshToken}
+	ts := p.config.TokenSource(goth.ContextForClient(p.Client()), token)
+	newToken, err := ts.Token()
+	if err != nil {
+		return nil, err
+	}
+	return newToken, err
+}

vendor/github.com/markbates/goth/providers/mastodon/session.go

@@ -0,0 +1,63 @@
+package mastodon
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/markbates/goth"
+)
+
+// Session stores data during the auth process with Gitea.
+type Session struct {
+	AuthURL      string
+	AccessToken  string
+	RefreshToken string
+	ExpiresAt    time.Time
+}
+
+var _ goth.Session = &Session{}
+
+// GetAuthURL will return the URL set by calling the `BeginAuth` function on the Gitea provider.
+func (s Session) GetAuthURL() (string, error) {
+	if s.AuthURL == "" {
+		return "", errors.New(goth.NoAuthUrlErrorMessage)
+	}
+	return s.AuthURL, nil
+}
+
+// Authorize the session with Gitea and return the access token to be stored for future use.
+func (s *Session) Authorize(provider goth.Provider, params goth.Params) (string, error) {
+	p := provider.(*Provider)
+	token, err := p.config.Exchange(goth.ContextForClient(p.Client()), params.Get("code"))
+	if err != nil {
+		return "", err
+	}
+
+	if !token.Valid() {
+		return "", errors.New("Invalid token received from provider")
+	}
+
+	s.AccessToken = token.AccessToken
+	s.RefreshToken = token.RefreshToken
+	s.ExpiresAt = token.Expiry
+	return token.AccessToken, err
+}
+
+// Marshal the session into a string
+func (s Session) Marshal() string {
+	b, _ := json.Marshal(s)
+	return string(b)
+}
+
+func (s Session) String() string {
+	return s.Marshal()
+}
+
+// UnmarshalSession wil unmarshal a JSON string into a session.
+func (p *Provider) UnmarshalSession(data string) (goth.Session, error) {
+	s := &Session{}
+	err := json.NewDecoder(strings.NewReader(data)).Decode(s)
+	return s, err
+}