#60 | Add Facebook Oauth provider

oauth2/facebook.go

@@ -0,0 +1,76 @@
+package oauth2
+
+import (
+	"github.com/tarent/loginsrv/model"
+	"fmt"
+	"net/http"
+	"io/ioutil"
+	"encoding/json"
+	"strings"
+)
+
+var facebookAPI = "https://graph.facebook.com/v2.12"
+
+func init() {
+	RegisterProvider(providerfacebook)
+}
+
+// facebookUser is used for parsing the facebook response
+type facebookUser struct {
+	UserID  string `json:"id,omitempty"`
+	Picture struct{
+		Data struct{
+			URL string `json:"url,omitempty"`
+		} `json:"data,omitempty"`
+	} `json:"picture,omitempty"`
+	Name    string `json:"name,omitempty"`
+	Email   string `json:"email,omitempty"`
+}
+
+var providerfacebook = Provider{
+	Name:     "facebook",
+	AuthURL:  "https://www.facebook.com/v2.12/dialog/oauth",
+	TokenURL: "https://graph.facebook.com/v2.12/oauth/access_token",
+	GetUserInfo: func(token TokenInfo) (model.UserInfo, string, error) {
+		fu := facebookUser{}
+
+		url := fmt.Sprintf("%v/me?access_token=%v&fields=name,email,id,picture", facebookAPI, token.AccessToken)
+
+		// For facebook return an application/json Content-type the Accept header should be set as 'application/json'
+		client := &http.Client{}
+		contentType := "application/json"
+		req, _ := http.NewRequest("GET", url, nil)
+		req.Header.Set("Accept", contentType)
+		resp, err := client.Do(req)
+
+		if err != nil {
+			return model.UserInfo{}, "", err
+		}
+
+		if !strings.Contains(resp.Header.Get("Content-Type"), contentType) {
+			return model.UserInfo{}, "", fmt.Errorf("wrong content-type on facebook get user info: %v", resp.Header.Get("Content-Type"))
+		}
+
+		if resp.StatusCode != 200 {
+			return model.UserInfo{}, "", fmt.Errorf("got http status %v on facebook get user info", resp.StatusCode)
+		}
+
+		b, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return model.UserInfo{}, "", fmt.Errorf("error reading facebook get user info: %v", err)
+		}
+
+		err = json.Unmarshal(b, &fu)
+		if err != nil {
+			return model.UserInfo{}, "", fmt.Errorf("error parsing facebook get user info: %v", err)
+		}
+
+		return model.UserInfo{
+			Sub:     fu.UserID,
+			Picture: fu.Picture.Data.URL,
+			Name:    fu.Name,
+			Email:   fu.Email,
+			Origin:  "facebook",
+		}, string(b), nil
+	},
+}

oauth2/facebook_test.go

@@ -0,0 +1,68 @@
+package oauth2
+
+import (
+	. "github.com/stretchr/testify/assert"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+var facebookTestUserResponse = `{
+    "id": "23456789012345678",
+    "name": "Facebook User",
+    "picture": {
+        "data": {
+            "height": 100,
+            "is_silhouette": false,
+            "url": "https://scontent.xx.fbcdn.net/v/t1.0-1/p100x100/example_facebook_image.jpg",
+            "width": 100
+        }
+    },
+    "email": "facebookuser@facebook.com"
+}`
+
+func Test_Facebook_getUserInfo(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		Equal(t, "secret", r.FormValue("access_token"))
+		w.Header().Set("Content-Type", "application/json; charset=utf-8")
+		w.Write([]byte(facebookTestUserResponse))
+	}))
+	defer server.Close()
+
+	facebookAPI = server.URL
+
+	u, rawJSON, err := providerfacebook.GetUserInfo(TokenInfo{AccessToken: "secret"})
+	NoError(t, err)
+	Equal(t, "23456789012345678", u.Sub)
+	Equal(t, "facebookuser@facebook.com", u.Email)
+	Equal(t, "Facebook User", u.Name)
+	Equal(t, facebookTestUserResponse, rawJSON)
+}
+
+func Test_Facebook_getUserInfo_WrongContentType(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		Equal(t, "secret", r.FormValue("access_token"))
+		w.Header().Set("Content-Type", "text/javascript; charset=utf-8")
+		w.Write([]byte(facebookTestUserResponse))
+	}))
+	defer server.Close()
+
+	facebookAPI = server.URL
+
+	_, _, err := providerfacebook.GetUserInfo(TokenInfo{AccessToken: "secret"})
+	Error(t, err)
+}
+
+func Test_Facebook_getUserInfo_WrongStatus(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		Equal(t, "secret", r.FormValue("access_token"))
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte(facebookTestUserResponse))
+	}))
+	defer server.Close()
+
+	facebookAPI = server.URL
+
+	_, _, err := providerfacebook.GetUserInfo(TokenInfo{AccessToken: "secret"})
+	Error(t, err)
+}

oauth2/provider_test.go

@@ -18,9 +18,14 @@ func Test_ProviderRegistration(t *testing.T) {
 	NotNil(t, bitbucket)
 	True(t, exist)
 
+	facebook, exist := GetProvider("facebook")
+	NotNil(t, facebook)
+	True(t, exist)
+
 	list := ProviderList()
-	Equal(t, 3, len(list))
+	Equal(t, 4, len(list))
 	Contains(t, list, "github")
 	Contains(t, list, "google")
 	Contains(t, list, "bitbucket")
+	Contains(t, list, "facebook")
 }