/**
 * 安全审计日志中间件
 * 记录所有安全相关事件
 */
import type { Context, Middleware } from "koa";
export type SecurityAuditMiddleware = Middleware & {
    close(): Promise<void>;
};
/** 为一个宿主创建独立的审计写入器；辅助审计函数会沿当前请求使用同一实例。 */
export declare function createSecurityAudit(auditLogDir: string): SecurityAuditMiddleware;
/**
 * 初始化安全审计日志
 */
export declare function initSecurityAudit(auditLogDir: string): void;
/**
 * 安全审计中间件
 */
export declare function securityAudit(): Middleware;
/**
 * 记录认证失败
 */
export declare function logAuthFailure(ctx: Context, reason: string): void;
/**
 * 记录无效令牌
 */
export declare function logInvalidToken(ctx: Context, token?: string): void;
/**
 * 记录可疑请求
 */
export declare function logSuspiciousRequest(ctx: Context, reason: string, details?: Record<string, unknown>): void;
/**
 * 记录速率限制触发
 */
export declare function logRateLimit(ctx: Context, key: string, count: number, max: number): void;
/**
 * 关闭审计日志
 */
export declare function closeSecurityAudit(): Promise<void>;