security: 全面安全加固 v2.1

严重修复:
- C1: JWT密钥生成64字节随机字符串替代硬编码占位符
- C2: 数据库密码改为随机强密码，移除宿主机端口映射
- C3: 管理员默认密码改为强密码

高危修复:
- H1: 移除数据库54326端口映射，仅内部网络访问
- H3: 添加X-Frame-Options/CSP/XSS-Protection等安全头
- H4: 前端所有innerHTML拼接处添加escapeHtml转义防XSS
- H5: SMTP密码在API响应中脱敏显示
- H6: 债务列表接口添加用户隔离，普通用户只能看自己的数据
- H7: 债务详情/计划/记录接口添加归属校验
- H8: 账户级暴力破解锁定(5次失败锁定5分钟)
- H9: 速率限制数据增加过期清理机制防内存泄漏

中危修复:
- M1: 注册/重置密码接口添加后端密码强度校验(最少8位)
- M4: 添加全局异常处理器，500错误不再暴露堆栈
- M5: Docker容器改为非root用户运行
- M6: 添加.dockerignore排除pyc和敏感文件
- M7: 管理员操作写入审计日志
- M8: CORS限制为实际使用的HTTP方法和头

其他:
- Nginx隐藏版本号(server_tokens off)
- 管理员角色修改添加枚举校验
- 密码重置验证码接口返回统一错误信息

backend/app/core/config.py

@@ -7,12 +7,12 @@ class Settings(BaseSettings):
     API_V1_PREFIX: str = "/api/v1"
     DATABASE_URL: str = "postgresql+asyncpg://postgres:postgres@db:5432/debt_manager"
     REDIS_URL: str = "redis://redis:6379/0"
-    SECRET_KEY: str = "your-secret-key-change-in-production"
+    SECRET_KEY: str = "562fa55e5e0cea1e00ff645be1da4f7c932439d97de7ffacd3d95156d9ccd7af"
     ACCESS_TOKEN_EXPIRE_MINUTES: int = 30
     REFRESH_TOKEN_EXPIRE_DAYS: int = 7
     CORS_ORIGINS: list[str] = ["http://localhost", "http://localhost:80", "http://localhost:806"]
     ADMIN_EMAIL: str = "admin@example.com"
-    ADMIN_PASSWORD: str = "admin123"
+    ADMIN_PASSWORD: str = "Adm1n!2026#Str0ng"
 
     SMTP_HOST: str = ""
     SMTP_PORT: int = 465

backend/app/core/rate_limit.py

@@ -3,21 +3,41 @@ from collections import defaultdict
 from fastapi import Request, HTTPException
 
 MAX_FAILURES = 10
+ACCOUNT_MAX_FAILURES = 5
 WINDOW_SECONDS = 300
 ALERT_THRESHOLDS = [3, 5, 10]
 
 _login_attempts: dict[str, list[float]] = defaultdict(list)
 _account_failures: dict[str, list[float]] = defaultdict(list)
 _account_notified: dict[str, set[int]] = defaultdict(set)
+_account_blocked: dict[str, float] = {}
+
+
+def _cleanup():
+    now = time.time()
+    expired_ips = [ip for ip, times in _login_attempts.items() if not times or now - times[-1] > WINDOW_SECONDS]
+    for ip in expired_ips:
+        del _login_attempts[ip]
+    expired_accounts = [acc for acc, times in _account_failures.items() if not times or now - times[-1] > WINDOW_SECONDS]
+    for acc in expired_accounts:
+        _account_failures.pop(acc, None)
+        _account_notified.pop(acc, None)
+    expired_blocked = [acc for acc, until in _account_blocked.items() if now > until]
+    for acc in expired_blocked:
+        del _account_blocked[acc]
 
 
 def record_login_failure(ip: str, account: str = ""):
+    _cleanup()
     now = time.time()
     _login_attempts[ip] = [t for t in _login_attempts[ip] if now - t < WINDOW_SECONDS]
     _login_attempts[ip].append(now)
     if account:
         _account_failures[account] = [t for t in _account_failures[account] if now - t < WINDOW_SECONDS]
         _account_failures[account].append(now)
+        count = len(_account_failures[account])
+        if count >= ACCOUNT_MAX_FAILURES:
+            _account_blocked[account] = now + WINDOW_SECONDS
 
 
 def clear_login_failures(ip: str, account: str = ""):
@@ -25,6 +45,7 @@ def clear_login_failures(ip: str, account: str = ""):
     if account:
         _account_failures.pop(account, None)
         _account_notified.pop(account, None)
+        _account_blocked.pop(account, None)
 
 
 def get_remaining_seconds(ip: str) -> int:
@@ -37,6 +58,16 @@ def get_remaining_seconds(ip: str) -> int:
     return max(remaining, 0)
 
 
+def get_account_remaining_seconds(account: str) -> int:
+    now = time.time()
+    if account in _account_blocked:
+        remaining = int(_account_blocked[account] - now)
+        if remaining > 0:
+            return remaining
+        del _account_blocked[account]
+    return 0
+
+
 def get_account_failure_count(account: str) -> int:
     now = time.time()
     _account_failures[account] = [t for t in _account_failures[account] if now - t < WINDOW_SECONDS]
@@ -59,6 +90,10 @@ def is_ip_blocked(ip: str) -> bool:
     return get_remaining_seconds(ip) > 0 and len(_login_attempts[ip]) >= MAX_FAILURES
 
 
+def is_account_blocked(account: str) -> bool:
+    return get_account_remaining_seconds(account) > 0
+
+
 async def ip_rate_limit_middleware(request: Request, call_next):
     ip = request.client.host if request.client else "unknown"
     if is_ip_blocked(ip):