To gitea and beyond, let's go(-yco)

internal/middleware/auth.go

@@ -0,0 +1,81 @@
+package middleware
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"strings"
+)
+
+type contextKey string
+
+const UserIDKey contextKey = "user_id"
+
+type TokenVerifier interface {
+	VerifyToken(token string) (uint, error)
+}
+
+func sendJSONError(w http.ResponseWriter, message string, statusCode int) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(statusCode)
+	json.NewEncoder(w).Encode(map[string]any{
+		"success": false,
+		"error":   message,
+		"message": message,
+	})
+}
+
+func NewAuth(verifier TokenVerifier) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			authHeader := strings.TrimSpace(r.Header.Get("Authorization"))
+			if authHeader == "" {
+				if strings.HasPrefix(r.URL.Path, "/api/") {
+					sendJSONError(w, "Authorization header required", http.StatusUnauthorized)
+				} else {
+					http.Error(w, "Authorization header required", http.StatusUnauthorized)
+				}
+				return
+			}
+
+			if !strings.HasPrefix(authHeader, "Bearer ") {
+				if strings.HasPrefix(r.URL.Path, "/api/") {
+					sendJSONError(w, "Invalid authorization header", http.StatusUnauthorized)
+				} else {
+					http.Error(w, "Invalid authorization header", http.StatusUnauthorized)
+				}
+				return
+			}
+
+			tokenString := strings.TrimSpace(strings.TrimPrefix(authHeader, "Bearer "))
+			if tokenString == "" {
+				if strings.HasPrefix(r.URL.Path, "/api/") {
+					sendJSONError(w, "Invalid authorization token", http.StatusUnauthorized)
+				} else {
+					http.Error(w, "Invalid authorization token", http.StatusUnauthorized)
+				}
+				return
+			}
+
+			userID, err := verifier.VerifyToken(tokenString)
+			if err != nil {
+				if strings.HasPrefix(r.URL.Path, "/api/") {
+					sendJSONError(w, "Invalid or expired token", http.StatusUnauthorized)
+				} else {
+					http.Error(w, "Invalid or expired token", http.StatusUnauthorized)
+				}
+				return
+			}
+
+			ctx := context.WithValue(r.Context(), UserIDKey, userID)
+			next.ServeHTTP(w, r.WithContext(ctx))
+		})
+	}
+}
+
+func GetUserIDFromContext(ctx context.Context) uint {
+	if userID, ok := ctx.Value(UserIDKey).(uint); ok {
+		return userID
+	}
+	return 0
+}