add oauth

Gopkg.toml

@@ -32,3 +32,7 @@
 [[constraint]]
   name = "github.com/satori/go.uuid"
   version = "1.1.0"
+
+[[constraint]]
+  branch = "master"
+  name = "golang.org/x/oauth2"

auth.go

@@ -30,6 +30,7 @@ type Auth interface {
 type UserService interface {
 	FindOneByID(string) (User, error)
 	FindOrCreateOneByEmail(string) (User, error)
+	FindOneByEmail(string) (User, error)
 }
 
 // RoleService is the contract which offers queries on the role entity

internal/http.go

@@ -0,0 +1,9 @@
+package internal
+
+import (
+	"net/http"
+)
+
+type HTTPClient interface {
+	Get(url string) (resp *http.Response, err error)
+}

internal/test/fixtures/oauth_provider.go

@@ -0,0 +1,71 @@
+package fixtures
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/hiendv/gate"
+	"github.com/hiendv/gate/internal"
+	"github.com/pkg/errors"
+	"golang.org/x/oauth2"
+)
+
+type OAuthClient struct {
+	token     *oauth2.Token
+	responses map[string]gate.HasEmail
+}
+
+var handler = func(w http.ResponseWriter, r *http.Request, user gate.HasEmail) {
+	result, err := json.Marshal(user)
+	if err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
+
+	fmt.Fprint(w, string(result))
+}
+
+func (client OAuthClient) Get(url string) (resp *http.Response, err error) {
+	if client.token == nil || client.token.AccessToken == "" {
+		err = errors.New("invalid token")
+		return
+	}
+
+	user := client.responses[client.token.AccessToken]
+
+	result, err := json.Marshal(user)
+	if err != nil {
+		return
+	}
+
+	return &http.Response{
+		Body: ioutil.NopCloser(bytes.NewBuffer(result)),
+	}, nil
+}
+
+type OAuthProvider struct {
+	Responses map[string]gate.HasEmail
+}
+
+func (config OAuthProvider) AuthCodeURL(state string, opts ...oauth2.AuthCodeOption) string {
+	return ""
+}
+
+func (config OAuthProvider) Exchange(ctx context.Context, code string) (*oauth2.Token, error) {
+	if code == "" {
+		return nil, nil
+	}
+
+	token := &oauth2.Token{}
+	token.AccessToken = fmt.Sprintf("%s-token", code)
+
+	return token, nil
+}
+
+func (config OAuthProvider) Client(ctx context.Context, token *oauth2.Token) internal.HTTPClient {
+	return OAuthClient{token, config.Responses}
+}

internal/test/fixtures/user.go

@@ -71,7 +71,18 @@ func (service MyUserService) FindOneByEmail(email string) (u gate.User, err erro
 	return
 }
 
-// FindOrCreateOneByEmail fetches the user with the given email or create a new one if the user doesn't exist
+// CreateOneByEmail creates the user with the given email
+func (service *MyUserService) CreateOneByEmail(email string) (u gate.User, err error) {
+	record := User{
+		ID:    service.GenerateMyUserID(),
+		Email: email,
+	}
+	service.records = append(service.records, record)
+	u = record
+	return
+}
+
+// FindOrCreateOneByEmail fetches the user with the given email or creates a new one if the user doesn't exist
 func (service *MyUserService) FindOrCreateOneByEmail(email string) (u gate.User, err error) {
 	u, err = service.FindOneByEmail(email)
 	if err == nil {
@@ -83,12 +94,6 @@ func (service *MyUserService) FindOrCreateOneByEmail(email string) (u gate.User,
 		return
 	}
 
-	err = nil
-	record := User{
-		ID:    service.GenerateMyUserID(),
-		Email: email,
-	}
-	service.records = append(service.records, record)
-	u = record
+	u, err = service.CreateOneByEmail(email)
 	return
 }

oauth/config.go

@@ -0,0 +1,43 @@
+package oauth
+
+import (
+	"github.com/hiendv/gate"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/facebook"
+	"golang.org/x/oauth2/google"
+)
+
+// Config is the configuration for OAuth authentication
+type Config struct {
+	gate.Config
+	ClientID     string
+	ClientSecret string
+	Scopes       []string
+	Endpoint     oauth2.Endpoint
+	RedirectURI  string
+	UserAPI      string
+}
+
+func NewGoogleConfig(base gate.Config, id, secret, redirectURI string) Config {
+	return Config{
+		base,
+		id,
+		secret,
+		[]string{"https://www.googleapis.com/auth/userinfo.email"},
+		google.Endpoint,
+		redirectURI,
+		"https://www.googleapis.com/oauth2/v3/userinfo",
+	}
+}
+
+func NewFacebookConfig(base gate.Config, id, secret, redirectURI string) Config {
+	return Config{
+		base,
+		id,
+		secret,
+		[]string{"email"},
+		facebook.Endpoint,
+		redirectURI,
+		"https://graph.facebook.com/v2.11/me?fields=id,name,email",
+	}
+}

oauth/doc.go

@@ -0,0 +1,2 @@
+// Package oauth is the OAuth2 authentication driver for github.com/hiendv/gate. It uses client implementations, not OAuth servers e.g. Google, Facebook, etc.
+package oauth

oauth/handlers.go

@@ -0,0 +1,56 @@
+package oauth
+
+import (
+	"encoding/json"
+
+	"github.com/hiendv/gate"
+	"github.com/pkg/errors"
+	"golang.org/x/oauth2"
+)
+
+type GoogleUser struct {
+	Email         string `json:"email"`
+	EmailVerified bool   `json:"email_verified"`
+}
+
+func (user GoogleUser) GetEmail() string {
+	if !user.EmailVerified {
+		return ""
+	}
+
+	return user.Email
+}
+
+var GoogleStatelessHandler LoginFunc = func(driver Driver, code, state string) (account gate.HasEmail, err error) {
+	// State is ignored
+
+	token, err := driver.provider.Exchange(oauth2.NoContext, code)
+	if err != nil {
+		return
+	}
+
+	client := driver.provider.Client(oauth2.NoContext, token)
+	if client == nil {
+		err = errors.New("invalid API client")
+		return
+	}
+
+	response, err := client.Get(driver.config.UserAPI)
+	if err != nil {
+		return
+	}
+	if response == nil {
+		err = errors.New("invalid API response")
+		return
+	}
+	defer response.Body.Close()
+
+	var user GoogleUser
+	err = json.NewDecoder(response.Body).Decode(&user)
+	if err != nil {
+		return
+	}
+
+	account = user
+	return
+}