Implement CSRF protection and security hardening across the application (#4179)

* Implement CSRF protection and security hardening across the application

- Added CSRF token handling in axios requests and HTML templates.
- Introduced CSRF middleware to validate tokens for unsafe HTTP methods.
- Implemented login limiter to prevent brute-force attacks.
- Enhanced security headers in middleware for improved response security.
- Updated login notification to include safe metadata without passwords.
- Added tests for CSRF middleware and login limiter functionality.

* fix

web/middleware/security_test.go

@@ -0,0 +1,121 @@
+package middleware
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/mhsanaei/3x-ui/v2/web/session"
+
+	"github.com/gin-contrib/sessions"
+	"github.com/gin-contrib/sessions/cookie"
+	"github.com/gin-gonic/gin"
+)
+
+func TestCSRFMiddlewareAllowsSafeMethods(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	router.Use(CSRFMiddleware())
+	router.GET("/safe", func(c *gin.Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/safe", nil)
+	router.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusOK)
+	}
+}
+
+func TestCSRFMiddlewareRejectsMissingTokenAndAcceptsValidToken(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	store := cookie.NewStore([]byte("01234567890123456789012345678901"))
+	router.Use(sessions.Sessions("3x-ui", store))
+	router.GET("/token", func(c *gin.Context) {
+		token, err := session.EnsureCSRFToken(c)
+		if err != nil {
+			t.Fatal(err)
+		}
+		c.String(http.StatusOK, token)
+	})
+	router.POST("/submit", CSRFMiddleware(), func(c *gin.Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	tokenRec := httptest.NewRecorder()
+	tokenReq := httptest.NewRequest(http.MethodGet, "/token", nil)
+	router.ServeHTTP(tokenRec, tokenReq)
+	if tokenRec.Code != http.StatusOK {
+		t.Fatalf("token status = %d, want %d", tokenRec.Code, http.StatusOK)
+	}
+	cookies := tokenRec.Result().Cookies()
+	token := tokenRec.Body.String()
+
+	missingRec := httptest.NewRecorder()
+	missingReq := httptest.NewRequest(http.MethodPost, "/submit", nil)
+	for _, cookie := range cookies {
+		missingReq.AddCookie(cookie)
+	}
+	router.ServeHTTP(missingRec, missingReq)
+	if missingRec.Code != http.StatusForbidden {
+		t.Fatalf("missing token status = %d, want %d", missingRec.Code, http.StatusForbidden)
+	}
+
+	validRec := httptest.NewRecorder()
+	validReq := httptest.NewRequest(http.MethodPost, "/submit", nil)
+	for _, cookie := range cookies {
+		validReq.AddCookie(cookie)
+	}
+	validReq.Header.Set(session.CSRFHeaderName, token)
+	router.ServeHTTP(validRec, validReq)
+	if validRec.Code != http.StatusOK {
+		t.Fatalf("valid token status = %d, want %d", validRec.Code, http.StatusOK)
+	}
+}
+
+func TestSecurityHeadersMiddleware(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	router.Use(SecurityHeadersMiddleware(true))
+	router.GET("/", func(c *gin.Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	router.ServeHTTP(rec, req)
+
+	headers := rec.Result().Header
+	if got := headers.Get("X-Content-Type-Options"); got != "nosniff" {
+		t.Fatalf("X-Content-Type-Options = %q", got)
+	}
+	if got := headers.Get("X-Frame-Options"); got != "DENY" {
+		t.Fatalf("X-Frame-Options = %q", got)
+	}
+	if got := headers.Get("Referrer-Policy"); got != "no-referrer" {
+		t.Fatalf("Referrer-Policy = %q", got)
+	}
+	if got := headers.Get("Strict-Transport-Security"); got == "" {
+		t.Fatal("Strict-Transport-Security should be set for direct HTTPS")
+	}
+}
+
+func TestSecurityHeadersMiddlewareSkipsHSTSWithoutDirectHTTPS(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	router := gin.New()
+	router.Use(SecurityHeadersMiddleware(false))
+	router.GET("/", func(c *gin.Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	router.ServeHTTP(rec, req)
+
+	if got := rec.Result().Header.Get("Strict-Transport-Security"); got != "" {
+		t.Fatalf("Strict-Transport-Security = %q, want empty", got)
+	}
+}