feat: 添加安全中间件、优化限流器与API密钥验证

1. 新增安全响应头中间件强化请求安全性
2. 使用恒定时间比较修复API密钥验证时序漏洞
3. 新增限流器条目上限配置与自动清理逻辑
4. 优化CORS日志与客户端IP获取逻辑
5. 升级Go构建环境与基础镜像版本
6. 新增非root用户运行容器增强安全性

middleware/auth.go

@@ -1,6 +1,7 @@
 package middleware
 
 import (
+	"crypto/subtle"
 	"encoding/json"
 	"log"
 	"net/http"
@@ -39,7 +40,7 @@ func ValidateAPIKey(r *http.Request) bool {
 
 	token := strings.TrimPrefix(authHeader, "Bearer ")
 	for _, validKey := range validAPIKeys {
-		if token == validKey {
+		if subtle.ConstantTimeCompare([]byte(token), []byte(validKey)) == 1 {
 			return true
 		}
 	}

middleware/cors.go

@@ -96,16 +96,13 @@ func CORS(next http.Handler) http.Handler {
 				} else if !strings.Contains(vary, "Origin") {
 					w.Header().Set("Vary", vary+", Origin")
 				}
+			} else {
+				log.Printf("CORS拦截: 来源=%q 路径=%s 方法=%s 客户端=%s",
+					origin, r.URL.Path, r.Method, GetClientIP(r))
 			}
 		}
 
 		if r.Method == http.MethodOptions {
-			if origin != "" {
-				if _, matched := matchOrigin(origin); !matched {
-					w.WriteHeader(http.StatusNoContent)
-					return
-				}
-			}
 			w.WriteHeader(http.StatusNoContent)
 			return
 		}

middleware/ratelimit.go

@@ -1,6 +1,7 @@
 package middleware
 
 import (
+	"log"
 	"net"
 	"net/http"
 	"strings"
@@ -77,6 +78,16 @@ func (rl *RateLimiter) cleanup() {
 			rl.requests[k] = valid
 		}
 	}
+
+	if len(rl.requests) > common.MaxRateLimiterEntries {
+		log.Printf("警告: 限流器条目数 %d 超过上限 %d，触发强制清理", len(rl.requests), common.MaxRateLimiterEntries)
+		for k := range rl.requests {
+			if len(rl.requests) <= common.MaxRateLimiterEntries/2 {
+				break
+			}
+			delete(rl.requests, k)
+		}
+	}
 }
 
 func GetClientIP(r *http.Request) string {
@@ -84,11 +95,14 @@ func GetClientIP(r *http.Request) string {
 	if xForwardedFor != "" {
 		ips := strings.Split(xForwardedFor, ",")
 		if len(ips) > 0 {
-			return strings.TrimSpace(ips[0])
+			ip := strings.TrimSpace(ips[0])
+			if ip != "" {
+				return ip
+			}
 		}
 	}
 
-	xRealIP := r.Header.Get("X-Real-IP")
+	xRealIP := strings.TrimSpace(r.Header.Get("X-Real-IP"))
 	if xRealIP != "" {
 		return xRealIP
 	}

middleware/security.go

@@ -0,0 +1,21 @@
+package middleware
+
+import (
+	"net/http"
+	"strings"
+)
+
+func SecurityHeaders(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Content-Type-Options", "nosniff")
+		w.Header().Set("X-Frame-Options", "DENY")
+		w.Header().Set("X-XSS-Protection", "1; mode=block")
+		w.Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
+
+		if strings.HasPrefix(r.URL.Path, "/v1/") || r.URL.Path == "/health" {
+			w.Header().Set("Cache-Control", "no-store")
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}