added jwt auth

internal/middlewares/auth.go

@@ -0,0 +1,81 @@
+package middlewares
+
+import (
+	"GoMembership/internal/config"
+	"GoMembership/pkg/logger"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/golang-jwt/jwt/v5"
+)
+
+var (
+	jwtKey           = []byte(config.Auth.JWTSecret)
+	jwtSigningMethod = jwt.SigningMethodHS256
+	jwtParser        = jwt.NewParser(jwt.WithValidMethods([]string{jwtSigningMethod.Alg()}))
+)
+
+func GenerateToken(userID string) (string, error) {
+	token := jwt.NewWithClaims(jwtSigningMethod, jwt.MapClaims{
+		"user_id": userID,
+		"exp":     time.Now().Add(time.Minute * 15).Unix(), // Token expires in 15 Minutes
+	})
+
+	return token.SignedString(jwtKey)
+}
+
+func verifyToken(tokenString string) (*jwt.Token, error) {
+	token, err := jwtParser.Parse(tokenString, func(_ *jwt.Token) (interface{}, error) {
+		return jwtKey, nil
+	})
+
+	if err != nil {
+		return nil, err
+	}
+
+	return token, nil
+}
+
+func AuthMiddleware() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		authHeader := c.GetHeader("Authorization")
+		if authHeader == "" {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "Authorization header is required"})
+			c.Abort()
+			return
+		}
+
+		bearerToken := strings.Split(authHeader, " ")
+		if len(bearerToken) != 2 {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token format"})
+			c.Abort()
+			return
+		}
+
+		tokenString := bearerToken[1]
+
+		token, err := verifyToken(tokenString)
+		if err != nil {
+			if err == jwt.ErrTokenSignatureInvalid {
+				logger.Error.Printf("JWT NULL ATTACK: %#v", err)
+				c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token signing method"})
+			} else {
+				c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token"})
+			}
+			c.Abort()
+			return
+		}
+
+		if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
+			userID := claims["user_id"].(string)
+			c.Set("user_id", userID)
+			c.Next()
+		} else {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid token claims"})
+			c.Abort()
+			return
+		}
+	}
+}