feat: add wechat provider

providers/wechat/session.go

@@ -0,0 +1,67 @@
+package wechat
+
+import (
+	"encoding/json"
+	"errors"
+	"strings"
+	"time"
+
+	"github.com/markbates/goth"
+)
+
+// Session stores data during the auth process with Wechat.
+type Session struct {
+	AuthURL      string
+	AccessToken  string
+	RefreshToken string
+	ExpiresAt    time.Time
+	Openid       string
+	Unionid      string
+}
+
+var _ goth.Session = &Session{}
+
+// GetAuthURL will return the URL set by calling the `BeginAuth` function on the Wepay provider.
+func (s Session) GetAuthURL() (string, error) {
+	if s.AuthURL == "" {
+		return "", errors.New(goth.NoAuthUrlErrorMessage)
+	}
+	return s.AuthURL, nil
+}
+
+// Authorize the session with Wepay 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, openid, err := p.fetchToken(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
+	s.Openid = openid
+	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
+}

providers/wechat/session_test.go

@@ -0,0 +1,48 @@
+package wechat_test
+
+import (
+	"testing"
+
+	"github.com/markbates/goth"
+	"github.com/markbates/goth/providers/wechat"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_Implements_Session(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &wechat.Session{}
+
+	a.Implements((*goth.Session)(nil), s)
+}
+
+func Test_GetAuthURL(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &wechat.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 := &wechat.Session{}
+
+	data := s.Marshal()
+	a.Equal(data, `{"AuthURL":"","AccessToken":"","RefreshToken":"","ExpiresAt":"0001-01-01T00:00:00Z"}`)
+}
+
+func Test_String(t *testing.T) {
+	t.Parallel()
+	a := assert.New(t)
+	s := &wechat.Session{}
+
+	a.Equal(s.String(), s.Marshal())
+}

providers/wechat/wechat.go

@@ -0,0 +1,237 @@
+package wechat
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/markbates/goth"
+	"golang.org/x/oauth2"
+)
+
+const (
+	AuthURL  = "https://open.weixin.qq.com/connect/qrconnect"
+	TokenURL = "https://api.weixin.qq.com/sns/oauth2/access_token"
+
+	ScopeSnsapiLogin = "snsapi_login"
+
+	ProfileURL = "https://api.weixin.qq.com/sns/userinfo"
+)
+
+type Provider struct {
+	providerName string
+	config       *oauth2.Config
+	httpClient   *http.Client
+	ClientID     string
+	ClientSecret string
+	RedirectURL  string
+	Lang         WechatLangType
+
+	AuthURL    string
+	TokenURL   string
+	ProfileURL string
+}
+
+type WechatLangType string
+
+const (
+	WECHAT_LANG_CN WechatLangType = "cn"
+	WECHAT_LANG_EN WechatLangType = "en"
+)
+
+// New creates a new Wechat provider, and sets up important connection details.
+// You should always call `wechat.New` to get a new Provider. Never try to create
+// one manually.
+func New(clientID, clientSecret, redirectURL string, lang WechatLangType) *Provider {
+	p := &Provider{
+		providerName: "wechat",
+		ClientID:     clientID,
+		ClientSecret: clientSecret,
+		RedirectURL:  redirectURL,
+		Lang:         lang,
+		AuthURL:      AuthURL,
+		TokenURL:     TokenURL,
+		ProfileURL:   ProfileURL,
+	}
+	p.config = newConfig(p)
+	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 wechat package.
+func (p *Provider) Debug(debug bool) {}
+
+// BeginAuth asks Wechat for an authentication end-point.
+func (p *Provider) BeginAuth(state string) (goth.Session, error) {
+	params := url.Values{}
+	params.Add("appid", p.ClientID)
+	params.Add("response_type", "code")
+	params.Add("state", state)
+	params.Add("scope", ScopeSnsapiLogin)
+	params.Add("redirect_uri", p.RedirectURL)
+	session := &Session{
+		AuthURL: fmt.Sprintf("%s?%s", p.AuthURL, params.Encode()),
+	}
+	return session, nil
+}
+
+// FetchUser will go to Wepay and access basic information 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,
+	}
+
+	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)
+	}
+
+	params := url.Values{}
+	params.Add("access_token", s.AccessToken)
+	params.Add("openid", s.Openid)
+	params.Add("lang", string(p.Lang))
+
+	url := fmt.Sprintf("%s?%s", p.ProfileURL, params.Encode())
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return user, err
+	}
+	resp, err := p.Client().Do(req)
+	if err != nil {
+		if resp != nil {
+			resp.Body.Close()
+		}
+		return user, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return user, fmt.Errorf("%s responded with a %d trying to fetch user information", p.providerName, resp.StatusCode)
+	}
+
+	err = userFromReader(resp.Body, &user)
+	return user, err
+}
+
+func newConfig(provider *Provider) *oauth2.Config {
+	c := &oauth2.Config{
+		ClientID:     provider.ClientID,
+		ClientSecret: provider.ClientSecret,
+		RedirectURL:  provider.RedirectURL,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  provider.AuthURL,
+			TokenURL: provider.TokenURL,
+		},
+		Scopes: []string{},
+	}
+
+	c.Scopes = append(c.Scopes, ScopeSnsapiLogin)
+
+	return c
+}
+
+func userFromReader(r io.Reader, user *goth.User) error {
+	u := struct {
+		Openid    string `json:"openid"`
+		Nickname  string `json:"nickname"`
+		Sex       int    `json:"sex"`
+		Province  string `json:"province"`
+		City      string `json:"city"`
+		Country   string `json:"country"`
+		AvatarURL string `json:"headimgurl"`
+		Unionid   string `json:"unionid"`
+		Code      int    `json:"errcode"`
+		Msg       string `json:"errmsg"`
+	}{}
+	err := json.NewDecoder(r).Decode(&u)
+	if err != nil {
+		return err
+	}
+
+	if len(u.Msg) > 0 {
+		return fmt.Errorf("CODE: %d, MSG: %s", u.Code, u.Msg)
+	}
+
+	user.Email = fmt.Sprintf("%[email protected]", u.Openid)
+	user.Name = u.Nickname
+	user.UserID = u.Openid
+	user.NickName = u.Nickname
+	user.Location = u.City
+	user.AvatarURL = u.AvatarURL
+	user.RawData = map[string]interface{}{
+		"Unionid": u.Unionid,
+	}
+	return nil
+}
+
+// RefreshTokenAvailable refresh token is provided by auth provider or not
+func (p *Provider) RefreshTokenAvailable() bool {
+	return false
+}
+
+// RefreshToken get new access token based on the refresh token
+func (p *Provider) RefreshToken(refreshToken string) (*oauth2.Token, error) {
+
+	return nil, nil
+}
+
+func (p *Provider) fetchToken(code string) (*oauth2.Token, string, error) {
+
+	params := url.Values{}
+	params.Add("appid", p.ClientID)
+	params.Add("secret", p.ClientSecret)
+	params.Add("grant_type", "authorization_code")
+	params.Add("code", code)
+	url := fmt.Sprintf("%s?%s", p.TokenURL, params.Encode())
+	resp, err := p.Client().Get(url)
+
+	if err != nil {
+		return nil, "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, "", fmt.Errorf("wechat /gettoken returns code: %d", resp.StatusCode)
+	}
+
+	obj := struct {
+		AccessToken string        `json:"access_token"`
+		ExpiresIn   time.Duration `json:"expires_in"`
+		Openid      string        `json:"openid"`
+		Code        int           `json:"errcode"`
+		Msg         string        `json:"errmsg"`
+	}{}
+	if err = json.NewDecoder(resp.Body).Decode(&obj); err != nil {
+		return nil, "", err
+	}
+	if obj.Code != 0 {
+		return nil, "", fmt.Errorf("CODE: %d, MSG: %s", obj.Code, obj.Msg)
+	}
+
+	token := &oauth2.Token{
+		AccessToken: obj.AccessToken,
+		Expiry:      time.Now().Add(obj.ExpiresIn * time.Second),
+	}
+
+	return token, obj.Openid, nil
+}