Logto Integration Attempt 1.

backend/internal/handlers/logto.go

@@ -0,0 +1,110 @@
+package handlers
+
+import (
+	"net/http"
+	"os"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-gonic/gin"
+	"github.com/logto-io/go/client"
+)
+
+// SessionStorage implements Logto's Storage interface using Gin sessions
+// Avoid cookie-based sessions due to size limits; use memory-based sessions for demo
+// In production, use Redis/MongoDB
+
+type SessionStorage struct {
+	session sessions.Session
+}
+
+func (s *SessionStorage) GetItem(key string) string {
+	value := s.session.Get(key)
+	if value == nil {
+		return ""
+	}
+	str, ok := value.(string)
+	if !ok {
+		return ""
+	}
+	return str
+}
+
+func (s *SessionStorage) SetItem(key, value string) {
+	s.session.Set(key, value)
+	s.session.Save()
+}
+
+// getLogtoConfig returns Logto config from environment variables
+func getLogtoConfig() *client.LogtoConfig {
+	return &client.LogtoConfig{
+		Endpoint:  os.Getenv("LOGTO_ENDPOINT"),
+		AppId:     os.Getenv("LOGTO_APP_ID"),
+		AppSecret: os.Getenv("LOGTO_APP_SECRET"),
+	}
+}
+
+// HomeHandler shows auth state and sign-in/sign-out links
+func HomeHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	authState := "You are not logged in to this website. :("
+	if logtoClient.IsAuthenticated() {
+		authState = "You are logged in to this website! :)"
+	}
+	homePage := "<h1>Hello Logto</h1>" +
+		"<div>" + authState + "</div>" +
+		`<div><a href="/service/auth/sign-in">Sign In</a></div>` +
+		`<div><a href="/service/auth/sign-out">Sign Out</a></div>`
+	ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
+}
+
+// SignInHandler starts the Logto sign-in flow
+func SignInHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	redirectUri := os.Getenv("LOGTO_REDIRECT_URI")
+	signInUri, err := logtoClient.SignIn(redirectUri)
+	if err != nil {
+		ctx.String(http.StatusInternalServerError, err.Error())
+		return
+	}
+	ctx.Redirect(http.StatusTemporaryRedirect, signInUri)
+}
+
+// CallbackHandler handles the Logto sign-in callback
+func CallbackHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	err := logtoClient.HandleSignInCallback(ctx.Request)
+	if err != nil {
+		ctx.String(http.StatusInternalServerError, err.Error())
+		return
+	}
+	// Redirect to the frontend page instead of the backend auth page
+	ctx.Redirect(http.StatusTemporaryRedirect, os.Getenv("BASE_URL"))
+}
+
+// SignOutHandler starts the Logto sign-out flow
+func SignOutHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	postSignOutRedirectUri := os.Getenv("LOGTO_POST_SIGN_OUT_REDIRECT_URI")
+	signOutUri, err := logtoClient.SignOut(postSignOutRedirectUri)
+	if err != nil {
+		ctx.String(http.StatusOK, err.Error())
+		return
+	}
+	ctx.Redirect(http.StatusTemporaryRedirect, signOutUri)
+}
+
+// UserIdTokenClaimsHandler returns the user's ID token claims as JSON
+func UserIdTokenClaimsHandler(ctx *gin.Context) {
+	session := sessions.Default(ctx)
+	logtoClient := client.NewLogtoClient(getLogtoConfig(), &SessionStorage{session: session})
+	idTokenClaims, err := logtoClient.GetIdTokenClaims()
+	if err != nil {
+		ctx.String(http.StatusOK, err.Error())
+		return
+	}
+	ctx.JSON(http.StatusOK, idTokenClaims)
+}

backend/internal/middleware/cors.go

@@ -0,0 +1,29 @@
+package middleware
+
+import (
+	"os"
+
+	"github.com/gin-contrib/cors"
+	"github.com/gin-gonic/gin"
+)
+
+// CORS returns a middleware that handles CORS requests
+// It only enables CORS in development mode
+func CORS() gin.HandlerFunc {
+	// Check if we're in development mode (you can use an environment variable for this)
+	if os.Getenv("GIN_MODE") != "release" {
+		// CORS configuration for development
+		config := cors.DefaultConfig()
+		config.AllowOrigins = []string{"http://localhost:3000"} // Frontend URL
+		config.AllowCredentials = true                          // Important for cookies/auth
+		config.AllowMethods = []string{"GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"}
+		config.AllowHeaders = []string{"Origin", "Content-Type", "Accept", "Authorization"}
+		
+		return cors.New(config)
+	}
+	
+	// In production, no CORS middleware is needed if frontend and backend are served from the same domain
+	return func(c *gin.Context) {
+		c.Next()
+	}
+} 

backend/internal/routes/router.go

@@ -9,6 +9,19 @@ import (
 
 // RegisterRoutes registers all API routes under the given group
 func RegisterRoutes(rg *gin.RouterGroup) {
+	// Apply CORS middleware first (before any other middleware)
+	rg.Use(middleware.CORS())
+	
+	// Then apply other middlewares
 	rg.Use(middleware.Logger())
+	
+	// Define routes
 	rg.GET("/health", handlers.HealthCheck)
-} 
+
+	// Logto authentication routes
+	rg.GET("/auth/", handlers.HomeHandler)
+	rg.GET("/auth/sign-in", handlers.SignInHandler)
+	rg.GET("/auth/callback", handlers.CallbackHandler)
+	rg.GET("/auth/sign-out", handlers.SignOutHandler)
+	rg.GET("/auth/user-id-token-claims", handlers.UserIdTokenClaimsHandler)
+}