feat: smtp3 C++20 重写 + 安全审计修复 (P0×2/P1-2/P2/P3 全部已修复)

- 新增 smtp3: pymsg/TCP :8008 邮件验证码服务 (smtp_v2.py 重写, 零新增依赖)
- 审计实证并修复 2 项 P0: SMTP 响应解析颠倒 (发送 100% 失败)、base64 符号扩展
- 修复 P1-2 SIGPIPE、P3-1 日志注入脱敏、P3-3 IPv6、P3-4 模偏差、P3-5 LogC 长连接复用
- 剩余 P1-1 (TLS 证书校验) 与端到端发信验证待 smtp.ini 凭据就绪
- 新增审计报告 docs/security/smtp3_SECURITY_AUDIT_20260809.md 并更新 INDEX

smtp3/Makefile

@@ -0,0 +1,20 @@
+CXX      := g++
+CXXFLAGS := -std=c++20 -Wall -Wextra -O2
+INCS     := -I./inc
+LIBS     := -lus_msg -lboost_json -lboost_program_options -lssl -lcrypto -lpthread
+
+TARGET   := smtp3.bin
+SRC      := src/main.cpp
+
+.PHONY: all clean install
+
+all: $(TARGET)
+
+$(TARGET): $(SRC)
+	$(CXX) $(CXXFLAGS) $(INCS) $^ $(LIBS) -o $@
+
+install: $(TARGET)
+	cp $(TARGET) /usr/local/bin/
+
+clean:
+	rm -f $(TARGET)

smtp3/_run.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+cd "$(dirname "$0")" || exit
+sleep 1
+exec ./smtp3.bin

smtp3/_set.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -euo pipefail
+cd "$(dirname "$0")" || exit
+
+make clean 2>/dev/null || true
+make
+echo "[smtp3] 编译完成 → ./smtp3.bin"

smtp3/inc/LogC.hpp

@@ -0,0 +1,124 @@
+/*
+ * LogC.hpp — smtp3 异步日志客户端（简化版）
+ *
+ * 基于 libmsg AsyncQueue，异步批量推送日志到 db:8005 的 Logs 表。
+ * - 内存队列 + 后台线程攒批（满 50 条或 2 秒 flush）
+ * - fail-safe：db 不可用时静默丢弃
+ * - P3-5: 长连接复用（底层 openConnection + pmsg_send/recv），
+ *   不再每批新建 TCP 连接；连接故障时关闭重建，本批丢弃
+ * - API: info() / warning() / error()
+ */
+#pragma once
+
+#include <us/Msg.hpp>
+#include <us/AsyncQueue.hpp>
+#include <boost/json.hpp>
+#include <iostream>
+#include <string>
+#include <vector>
+#include <chrono>
+#include <cstdlib>
+
+#include <unistd.h>
+
+namespace smtp3 {
+
+struct LogEntry {
+	std::string ts;
+	std::string service;
+	std::string level;
+	std::string message;
+	std::string trace_id;
+	std::string extra;
+};
+
+class LogC {
+public:
+	static LogC& instance() {
+		static LogC inst;
+		return inst;
+	}
+
+	void info(const std::string& svc, const std::string& msg) {
+		push(svc, "INFO", msg);
+	}
+	void warning(const std::string& svc, const std::string& msg) {
+		push(svc, "WARNING", msg);
+	}
+	void error(const std::string& svc, const std::string& msg) {
+		push(svc, "ERROR", msg);
+	}
+
+private:
+	LogC() {
+		const char* host = std::getenv("DB_HOST");
+		const char* port = std::getenv("DB_PORT");
+		db_host_ = host ? host : "127.0.0.1";
+		db_port_ = port ? std::atoi(port) : 8005;
+
+		queue_ = std::make_unique<pmc::net::AsyncQueue<LogEntry>>(
+			[this](std::vector<LogEntry>&& batch) { send_batch(std::move(batch)); },
+			pmc::net::AsyncQueueConfig{.batch_size = 50, .flush_interval = 2.0, .max_queue_size = 10000},
+			[](const std::exception& e, std::vector<LogEntry>&&) {
+				std::cerr << "[smtp3/log] send failed: " << e.what() << std::endl;
+			});
+		queue_->start();
+	}
+
+	~LogC() {
+		if (queue_) queue_->shutdown();
+		if (fd_ >= 0) ::close(fd_);
+	}
+
+	void push(const std::string& svc, const std::string& level, const std::string& msg) {
+		auto now = std::chrono::system_clock::now();
+		auto t = std::chrono::system_clock::to_time_t(now);
+		char buf[32];
+		std::strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%SZ", std::gmtime(&t));
+
+		LogEntry e;
+		e.ts = buf;
+		e.service = svc;
+		e.level = level;
+		e.message = msg;
+		queue_->push(std::move(e));
+	}
+
+	// P3-5: 长连接复用——同一 fd 上逐条 pmsg_send + pmsg_recv（db 对每条
+	// execute 都回复，须消费以保持帧同步）；任一异常即关闭连接、丢弃本批
+	void send_batch(std::vector<LogEntry>&& batch) {
+		try {
+			if (fd_ < 0)
+				fd_ = pmc::net::detail::openConnection(db_host_, db_port_, 1.0);
+			for (auto& e : batch) {
+				boost::json::object vals;
+				vals["ts"] = e.ts;
+				vals["service"] = e.service;
+				vals["level"] = e.level;
+				vals["message"] = e.message;
+				vals["trace_id"] = e.trace_id.empty() ? nullptr : boost::json::value(e.trace_id);
+				vals["extra"] = e.extra.empty() ? nullptr : boost::json::value(e.extra);
+
+				boost::json::object req;
+				req["_route"] = "execute";
+				req["action"] = "insert";
+				req["table"] = "Logs";
+				req["values"] = vals;
+
+				// 与 MsgClient::call 线路格式一致：无前缀，逐条请求-应答
+				pmc::net::pmsg_send(fd_, boost::json::serialize(req));
+				(void)pmc::net::pmsg_recv(fd_, 1.0);
+			}
+		} catch (const std::exception& e) {
+			if (fd_ >= 0) { ::close(fd_); fd_ = -1; }
+			std::cerr << "[smtp3/log] batch drop: " << e.what() << std::endl;
+		}
+	}
+
+	std::string db_host_;
+	int db_port_;
+	std::unique_ptr<pmc::net::AsyncQueue<LogEntry>> queue_;
+	int fd_ = -1;   // 长连接 fd（仅后台 flush 线程访问，无并发）
+};
+
+} // namespace smtp3