Fix LDAP authentication stability

src/services/auth/ldap.py

@@ -34,6 +34,22 @@ def escape_ldap_filter(value: str) -> str:
     return value
 
 
+def _get_attr_value(entry, attr_name: str, default: str = "") -> str:
+    """
+    提取 LDAP 条目属性的首个值，避免返回字符串化的列表表示。
+    """
+    attr = getattr(entry, attr_name, None)
+    if not attr:
+        return default
+    # ldap3 的 EntryAttribute.value 已经是单值或列表，根据类型取首个
+    val = getattr(attr, "value", None)
+    if isinstance(val, list):
+        val = val[0] if val else default
+    if val is None:
+        return default
+    return str(val)
+
+
 class LDAPService:
     """LDAP 认证服务"""
 
@@ -80,6 +96,9 @@ class LDAPService:
             logger.warning("LDAP 未配置或未启用")
             return None
 
+        admin_conn = None
+        user_conn = None
+
         try:
             # 创建服务器连接
             use_ssl = config.server_url.startswith("ldaps://")
@@ -113,12 +132,10 @@ class LDAPService:
 
             if not admin_conn.entries:
                 logger.warning(f"LDAP 用户未找到: {username}")
-                admin_conn.unbind()
                 return None
 
             user_entry = admin_conn.entries[0]
             user_dn = user_entry.entry_dn
-            admin_conn.unbind()
 
             # 用户密码验证
             user_conn = Connection(server, user=user_dn, password=password)
@@ -129,11 +146,9 @@ class LDAPService:
                 logger.warning(f"LDAP 密码验证失败: {username}")
                 return None
 
-            user_conn.unbind()
-
-            # 提取用户属性
-            email = str(getattr(user_entry, config.email_attr, "")) or f"{username}@ldap.local"
-            display_name = str(getattr(user_entry, config.display_name_attr, "")) or username
+            # 提取用户属性（优先用 LDAP 提供的值，不合法则回退默认）
+            email = _get_attr_value(user_entry, config.email_attr, f"{username}@ldap.local")
+            display_name = _get_attr_value(user_entry, config.display_name_attr, username)
 
             logger.info(f"LDAP 认证成功: {username}")
             return {
@@ -151,6 +166,18 @@ class LDAPService:
         except Exception as e:
             logger.error(f"LDAP 认证异常: {e}")
             return None
+        finally:
+            # 确保连接关闭，避免失败路径泄漏
+            if admin_conn:
+                try:
+                    admin_conn.unbind()
+                except Exception:
+                    pass
+            if user_conn:
+                try:
+                    user_conn.unbind()
+                except Exception:
+                    pass
 
     @staticmethod
     def test_connection(db: Session) -> Tuple[bool, str]: