Support for VK.com

Author: rkashapov

README.md

@@ -54,6 +54,7 @@ $ go get github.com/markbates/goth
 * Twitch
 * Twitter
 * Uber
+* VK
 * Wepay
 * Xero
 * Yahoo

examples/main.go

@@ -49,6 +49,7 @@ import (
 	"github.com/markbates/goth/providers/twitch"
 	"github.com/markbates/goth/providers/twitter"
 	"github.com/markbates/goth/providers/uber"
+	"github.com/markbates/goth/providers/vk"
 	"github.com/markbates/goth/providers/wepay"
 	"github.com/markbates/goth/providers/xero"
 	"github.com/markbates/goth/providers/yahoo"
@@ -106,6 +107,7 @@ func main() {
 		//Auth0 allocates domain per customer, a domain must be provided for auth0 to work
 		auth0.New(os.Getenv("AUTH0_KEY"), os.Getenv("AUTH0_SECRET"), "http://localhost:3000/auth/auth0/callback", os.Getenv("AUTH0_DOMAIN")),
 		xero.New(os.Getenv("XERO_KEY"), os.Getenv("XERO_SECRET"), "http://localhost:3000/auth/xero/callback"),
+		vk.New(os.Getenv("VK_KEY"), os.Getenv("VK_SECRET"), "http://localhost:3000/auth/vk/callback"),
 	)
 
 	// OpenID Connect is based on OpenID Connect Auto Discovery URL (https://openid.net/specs/openid-connect-discovery-1_0-17.html)
@@ -157,6 +159,7 @@ func main() {
 	m["auth0"] = "Auth0"
 	m["openid-connect"] = "OpenID Connect"
 	m["xero"] = "Xero"
+	m["vk"] = "VK"
 
 	var keys []string
 	for k := range m {

providers/vk/session.go

@@ -0,0 +1,69 @@
+package vk
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/markbates/goth"
+)
+
+// Session stores data during the auth process with VK.
+type Session struct {
+	AuthURL     string
+	AccessToken string
+	ExpiresAt   time.Time
+	userID      int64
+	email       string
+}
+
+// GetAuthURL returns the URL for the authentication end-point for the provider.
+func (s *Session) GetAuthURL() (string, error) {
+	if s.AuthURL == "" {
+		return "", errors.New(goth.NoAuthUrlErrorMessage)
+	}
+	return s.AuthURL, nil
+}
+
+// Marshal the session into a string
+func (s *Session) Marshal() string {
+	b, _ := json.Marshal(s)
+	return string(b)
+}
+
+// Authorize the session with VK 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")
+	}
+
+	email, ok := token.Extra("email").(string)
+	if !ok {
+		return "", errors.New("Cannot fetch user email")
+	}
+
+	userID, ok := token.Extra("user_id").(float64)
+	if !ok {
+		return "", errors.New("Cannot fetch user ID")
+	}
+
+	s.AccessToken = token.AccessToken
+	s.ExpiresAt = token.Expiry
+	s.email = email
+	s.userID = int64(userID)
+	return s.AccessToken, err
+}
+
+// UnmarshalSession will unmarshal a JSON string into a session.
+func (p *Provider) UnmarshalSession(data string) (goth.Session, error) {
+	sess := new(Session)
+	err := json.NewDecoder(strings.NewReader(data)).Decode(&sess)
+	return sess, err
+}

providers/vk/session_test.go

@@ -0,0 +1,40 @@
+package vk_test
+
+import (
+	"testing"
+
+	"github.com/markbates/goth"
+	"github.com/markbates/goth/providers/vk"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Implements_Session(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &vk.Session{}
+
+	a.Implements((*goth.Session)(nil), s)
+}
+
+func Test_GetAuthURL(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &vk.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 := &vk.Session{}
+
+	data := s.Marshal()
+	a.Equal(data, `{"AuthURL":"","AccessToken":"","ExpiresAt":"0001-01-01T00:00:00Z"}`)
+}

providers/vk/vk.go

@@ -0,0 +1,180 @@
+// Package vk implements the OAuth2 protocol for authenticating users through vk.com.
+// This package can be used as a reference implementation of an OAuth2 provider for Goth.
+package vk
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/markbates/goth"
+	"golang.org/x/oauth2"
+)
+
+var (
+	authURL      = "https://oauth.vk.com/authorize"
+	tokenURL     = "https://oauth.vk.com/access_token"
+	endpointUser = "https://api.vk.com/method/users.get"
+	apiVersion   = "5.71"
+)
+
+// New creates a new VK provider and sets up important connection details.
+// You should always call `vk.New` to get a new provider.  Never try to
+// create one manually.
+func New(clientKey, secret, callbackURL string, scopes ...string) *Provider {
+	p := &Provider{
+		ClientKey:    clientKey,
+		Secret:       secret,
+		CallbackURL:  callbackURL,
+		providerName: "vk",
+	}
+	p.config = newConfig(p, scopes)
+	return p
+}
+
+// Provider is the implementation of `goth.Provider` for accessing Github.
+type Provider struct {
+	ClientKey    string
+	Secret       string
+	CallbackURL  string
+	HTTPClient   *http.Client
+	config       *oauth2.Config
+	providerName string
+	version      string
+}
+
+// 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)
+}
+
+// BeginAuth asks VK for an authentication end-point.
+func (p *Provider) BeginAuth(state string) (goth.Session, error) {
+	url := p.config.AuthCodeURL(state)
+	session := &Session{
+		AuthURL: url,
+	}
+
+	return session, nil
+}
+
+// FetchUser will go to VK 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(),
+		ExpiresAt:   sess.ExpiresAt,
+		Email:       sess.email,
+	}
+
+	if user.AccessToken == "" {
+		return user, fmt.Errorf("%s cannot get user information without accessToken", p.providerName)
+	}
+
+	fields := "photo_200,nickname"
+	requestURL := fmt.Sprintf("%s?user_ids=%d&fields=%s&access_token=%s&v=%s", endpointUser, sess.userID, fields, sess.AccessToken, apiVersion)
+	response, err := p.Client().Get(requestURL)
+	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)
+
+	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 userFromReader(reader io.Reader, user *goth.User) error {
+	response := struct {
+		Response []struct {
+			ID        int    `json:"id"`
+			FirstName string `json:"first_name"`
+			LastName  string `json:"last_name"`
+			NickName  string `json:"nickname"`
+			Photo200  string `json:"photo_200"`
+		} `json:"response"`
+	}{}
+
+	err := json.NewDecoder(reader).Decode(&response)
+	if err != nil {
+		return err
+	}
+
+	if len(response.Response) == 0 {
+		return fmt.Errorf("vk cannot get user information")
+	}
+
+	u := response.Response[0]
+
+	user.UserID = string(u.ID)
+	user.FirstName = u.FirstName
+	user.LastName = u.LastName
+	user.NickName = u.NickName
+	user.AvatarURL = u.Photo200
+
+	return err
+}
+
+// Debug is a no-op for the vk package.
+func (p *Provider) Debug(debug bool) {}
+
+//RefreshToken refresh token is not provided by vk
+func (p *Provider) RefreshToken(refreshToken string) (*oauth2.Token, error) {
+	return nil, errors.New("Refresh token is not provided by vk")
+}
+
+//RefreshTokenAvailable refresh token is not provided by vk
+func (p *Provider) RefreshTokenAvailable() bool {
+	return false
+}
+
+func newConfig(provider *Provider, 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{
+			"email",
+		},
+	}
+
+	defaultScopes := map[string]struct{}{
+		"email": {},
+	}
+
+	for _, scope := range scopes {
+		if _, exists := defaultScopes[scope]; !exists {
+			c.Scopes = append(c.Scopes, scope)
+		}
+	}
+
+	return c
+}