Merge pull request markbates#105 from VagantemNumen/discord-oauth2

Adds Discord provider.

Author: markbates

examples/main.go

@@ -18,6 +18,7 @@ import (
 	"github.com/markbates/goth/providers/dailymotion"
 	"github.com/markbates/goth/providers/deezer"
 	"github.com/markbates/goth/providers/digitalocean"
+	"github.com/markbates/goth/providers/discord"
 	"github.com/markbates/goth/providers/dropbox"
 	"github.com/markbates/goth/providers/facebook"
 	"github.com/markbates/goth/providers/fitbit"
@@ -90,6 +91,7 @@ func main() {
 		gitlab.New(os.Getenv("GITLAB_KEY"), os.Getenv("GITLAB_SECRET"), "http://localhost:3000/auth/gitlab/callback"),
 		dailymotion.New(os.Getenv("DAILYMOTION_KEY"), os.Getenv("DAILYMOTION_SECRET"), "http://localhost:3000/auth/dailymotion/callback", "email"),
 		deezer.New(os.Getenv("DEEZER_KEY"), os.Getenv("DEEZER_SECRET"), "http://localhost:3000/auth/deezer/callback", "email"),
+		discord.New(os.Getenv("DISCORD_KEY"), os.Getenv("DISCORD_SECRET"), "http://localhost:3000/auth/discord/callback", discord.ScopeIdentify, discord.ScopeEmail),
 	)
 
 	m := make(map[string]string)
@@ -99,6 +101,7 @@ func main() {
 	m["dailymotion"] = "Dailymotion"
 	m["deezer"] = "Deezer"
 	m["digitalocean"] = "Digital Ocean"
+	m["discord"] = "Discord"
 	m["dropbox"] = "Dropbox"
 	m["facebook"] = "Facebook"
 	m["fitbit"] = "Fitbit"

providers/discord/discord.go

@@ -0,0 +1,187 @@
+// Package discord implements the OAuth2 protocol for authenticating users through Discord.
+// This package can be used as a reference implementation of an OAuth2 provider for Discord.
+package discord
+
+import (
+	"bytes"
+	"encoding/json"
+	"github.com/markbates/goth"
+	"golang.org/x/oauth2"
+	"io"
+	"io/ioutil"
+
+	"net/http"
+)
+
+const (
+	authURL      string = "https://discordapp.com/api/oauth2/authorize"
+	tokenURL     string = "https://discordapp.com/api/oauth2/token"
+	userEndpoint string = "https://discordapp.com/api/users/@me"
+)
+
+const (
+	// allows /users/@me without email
+	ScopeIdentify string = "identify"
+	// enables /users/@me to return an email
+	ScopeEmail string = "email"
+	// allows /users/@me/connections to return linked Twitch and YouTube accounts
+	ScopeConnections string = "connections"
+	// allows /users/@me/guilds to return basic information about all of a user's guilds
+	ScopeGuilds string = "guilds"
+	// allows /invites/{invite.id} to be used for joining a user's guild
+	ScopeJoinGuild string = "guilds.join"
+	// allows your app to join users to a group dm
+	ScopeGroupDMjoin string = "gdm.join"
+	// for oauth2 bots, this puts the bot in the user's selected guild by default
+	ScopeBot string = "bot"
+	// 	this generates a webhook that is returned in the oauth token response for authorization code grants
+	ScopeWebhook string = "webhook.incoming"
+)
+
+// New creates a new Discord provider, and sets up important connection details.
+// You should always call `discord.New` to get a new Provider. Never try to create
+// one manually.
+func New(clientKey string, secret string, callbackURL string, scopes ...string) *Provider {
+	p := &Provider{
+		ClientKey:   clientKey,
+		Secret:      secret,
+		CallbackURL: callbackURL,
+	}
+	p.config = newConfig(p, scopes)
+	return p
+}
+
+// Provider is the implementation of `goth.Provider` for accessing Discord
+type Provider struct {
+	ClientKey   string
+	Secret      string
+	CallbackURL string
+	config      *oauth2.Config
+}
+
+// Name gets the name used to retrieve this provider.
+func (p *Provider) Name() string {
+	return "discord"
+}
+
+// Debug is no-op for the Discord package.
+func (p *Provider) Debug(debug bool) {}
+
+// BeginAuth asks Discord for an authentication end-point.
+func (p *Provider) BeginAuth(state string) (goth.Session, error) {
+
+	url := p.config.AuthCodeURL(state, oauth2.AccessTypeOnline)
+
+	s := &Session{
+		AuthURL: url,
+	}
+	return s, nil
+}
+
+// FetchUser will go to Discord and access basic info about the user.
+func (p *Provider) FetchUser(session goth.Session) (goth.User, error) {
+
+	s := session.(*Session)
+
+	user := goth.User{
+		AccessToken:  s.AccessToken,
+		Provider:     p.Name(),
+		RefreshToken: s.RefreshToken,
+		ExpiresAt:    s.ExpiresAt,
+	}
+
+	req, err := http.NewRequest("GET", userEndpoint, nil)
+	if err != nil {
+		return user, err
+	}
+	req.Header.Set("Accept", "application/json")
+	req.Header.Set("Authorization", "Bearer "+s.AccessToken)
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		if resp != nil {
+			resp.Body.Close()
+		}
+		return user, err
+	}
+	defer resp.Body.Close()
+
+	bits, err := ioutil.ReadAll(resp.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)
+	if err != nil {
+		return user, err
+	}
+
+	return user, err
+}
+
+func userFromReader(r io.Reader, user *goth.User) error {
+	u := struct {
+		Name          string `json:"username"`
+		Email         string `json:"email"`
+		AvatarID      string `json:"avatar"`
+		MFAEnabled    bool   `json:"mfa_enabled"`
+		Discriminator string `json:"discriminator"`
+		Verified      bool   `json:"verified"`
+		ID            string `json:"id"`
+	}{}
+
+	err := json.NewDecoder(r).Decode(&u)
+	if err != nil {
+		return err
+	}
+
+	user.Name = u.Name
+	user.Email = u.Email
+	user.AvatarURL = "https://discordapp.com/api/users/" + u.ID + "/avatars/" + u.AvatarID + ".jpg"
+	user.UserID = u.ID
+
+	return nil
+}
+
+func newConfig(p *Provider, scopes []string) *oauth2.Config {
+	c := &oauth2.Config{
+		ClientID:     p.ClientKey,
+		ClientSecret: p.Secret,
+		RedirectURL:  p.CallbackURL,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  authURL,
+			TokenURL: tokenURL,
+		},
+		Scopes: []string{},
+	}
+
+	if len(scopes) > 0 {
+		for _, scope := range scopes {
+			c.Scopes = append(c.Scopes, scope)
+		}
+	} else {
+		c.Scopes = []string{ScopeIdentify}
+	}
+
+	return c
+}
+
+//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(oauth2.NoContext, token)
+	newToken, err := ts.Token()
+	if err != nil {
+		return nil, err
+	}
+	return newToken, err
+}

providers/discord/discord_test.go

@@ -0,0 +1,54 @@
+package discord
+
+import (
+	"os"
+	"testing"
+
+	"github.com/markbates/goth"
+	"github.com/stretchr/testify/assert"
+)
+
+func provider() *Provider {
+	return New(os.Getenv("DISCORD_KEY"),
+		os.Getenv("DISCORD_SECRET"), "/foo", "user")
+}
+
+func Test_New(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	p := provider()
+
+	a.Equal(p.ClientKey, os.Getenv("DISCORD_KEY"))
+	a.Equal(p.Secret, os.Getenv("DISCORD_SECRET"))
+	a.Equal(p.CallbackURL, "/foo")
+}
+
+func Test_ImplementsProvider(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	a.Implements((*goth.Provider)(nil), provider())
+}
+
+func Test_BeginAuth(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+
+	p := provider()
+	session, err := p.BeginAuth("test_state")
+	s := session.(*Session)
+	a.NoError(err)
+	a.Contains(s.AuthURL, "discordapp.com/api/oauth2/authorize")
+}
+
+func Test_SessionFromJSON(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+
+	p := provider()
+	session, err := p.UnmarshalSession(`{"AuthURL":"https://discordapp.com/api/oauth2/authorize", "AccessToken":"1234567890"}`)
+	a.NoError(err)
+
+	s := session.(*Session)
+	a.Equal(s.AuthURL, "https://discordapp.com/api/oauth2/authorize")
+	a.Equal(s.AccessToken, "1234567890")
+}

providers/discord/session.go

@@ -0,0 +1,65 @@
+package discord
+
+import (
+	"encoding/json"
+	"errors"
+	"github.com/markbates/goth"
+	"golang.org/x/oauth2"
+	"strings"
+	"time"
+)
+
+// Session stores data during the auth process with Discord
+type Session struct {
+	AuthURL      string
+	AccessToken  string
+	RefreshToken string
+	ExpiresAt    time.Time
+}
+
+// GetAuthURL will return the URL set by calling the `BeginAuth` function on
+// the Discord provider.
+func (s Session) GetAuthURL() (string, error) {
+	if s.AuthURL == "" {
+		return "", errors.New("Discord: An AuthURL has not been set")
+	}
+	return s.AuthURL, nil
+}
+
+// Authorize completes the authorization with Discord and returns 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(oauth2.NoContext, 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 marshals a session into a JSON string.
+func (s Session) Marshal() string {
+	j, _ := json.Marshal(s)
+	return string(j)
+}
+
+// String is equivalent to Marshal. It returns a JSON representation of the
+// of the session.
+func (s Session) String() string {
+	return s.Marshal()
+}
+
+// UnmarshalSession will 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
+}

providers/discord/session_test.go

@@ -0,0 +1,38 @@
+package discord
+
+import (
+	"testing"
+
+	"github.com/markbates/goth"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_ImplementsSession(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &Session{}
+	a.Implements((*goth.Session)(nil), s)
+}
+
+func Test_GetAuthURL(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &Session{}
+
+	_, err := s.GetAuthURL()
+	a.Error(err)
+
+	s.AuthURL = "/foo"
+
+	url, _ := s.GetAuthURL()
+	a.Equal(url, "/foo")
+}
+
+func Test_ToJSON(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &Session{}
+
+	data := s.Marshal()
+	a.Equal(data, `{"AuthURL":"","AccessToken":"","RefreshToken":"","ExpiresAt":"0001-01-01T00:00:00Z"}`)
+}