kevin
f2493da03e
- 封禁规则：达到失败阈值记为一次触发，前 3 次只计数不封禁； 第 4 次起封禁并按档位递增：30分钟（ban_duration_min）→ 3小时 → 3个月 → 半年（上限）；封禁过期后保留记录作为升档依据， 成功登录或管理员解封清零 - BanEntry 新增 BanCount（累计触发次数），每 IP 一条记录 upsert， 不再重复建行；RecordAuthFailure 统一 Web/LDAP/SMTP/IMAP/POP3 五处封禁逻辑，原因带档位（如"第1次封禁：登录失败次数过多 （第4次触发，失败5次）"） - 黑名单页修复：列表仅显示已封禁或曾封禁记录（原因/到期时间必填）， 新增封禁次数列与封禁中/已过期状态徽章，移除清理过期按钮 - 用户封禁页显示第 N 次封禁档位；新增档位升级与列表过滤单测
627 lines
17 KiB
Go
627 lines
17 KiB
Go
package pop3_server
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import (
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"bufio"
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"crypto/tls"
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"fmt"
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"log"
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"net"
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"strconv"
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"strings"
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"sync"
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"time"
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"mail_go/config"
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"mail_go/internal/db"
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"mail_go/internal/store"
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"mail_go/internal/tlsutil"
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)
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// POP3Server implements a simple POP3 mail server over TCP.
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type POP3Server struct {
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listener net.Listener
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stores *store.Stores
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cfg config.POP3Config
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banCfg config.BanConfig
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tlsLoader *tlsutil.Loader
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wg sync.WaitGroup
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}
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// NewPOP3Server creates a new POP3 server instance. tlsLoader may be nil
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// when TLS is not configured.
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func NewPOP3Server(cfg config.POP3Config, stores *store.Stores, tlsLoader *tlsutil.Loader, banCfg config.BanConfig) *POP3Server {
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return &POP3Server{stores: stores, cfg: cfg, banCfg: banCfg, tlsLoader: tlsLoader}
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}
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func (s *POP3Server) tlsConfig() (*tls.Config, error) {
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if s.tlsLoader == nil {
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return nil, fmt.Errorf("POP3 TLS certificate or key not configured")
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}
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// GetCertificate 每次握手按需重载证书，证书更新后无需重启服务
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return &tls.Config{GetCertificate: s.tlsLoader.GetCertificate}, nil
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}
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// Start starts the POP3 server on the configured plain-text port.
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func (s *POP3Server) Start() error {
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var err error
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s.listener, err = net.Listen("tcp", s.cfg.Addr)
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if err != nil {
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return fmt.Errorf("POP3 listen failed: %w", err)
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}
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port := parseAddrPort(s.cfg.Addr)
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log.Printf("POP3 server listening on %s", s.cfg.Addr)
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s.wg.Add(1)
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go func() {
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defer s.wg.Done()
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for {
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conn, err := s.listener.Accept()
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if err != nil {
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return
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}
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s.wg.Add(1)
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go func() {
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defer s.wg.Done()
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s.handleConn(conn, port)
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}()
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}
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}()
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return nil
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}
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// StartTLS starts the POP3 server on the configured TLS port.
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func (s *POP3Server) StartTLS() error {
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tlsConfig, err := s.tlsConfig()
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if err != nil {
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return err
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}
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listener, err := tls.Listen("tcp", s.cfg.TLSAddr, tlsConfig)
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if err != nil {
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return fmt.Errorf("POP3 TLS listen failed: %w", err)
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}
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port := parseAddrPort(s.cfg.TLSAddr)
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log.Printf("POP3 TLS server listening on %s", s.cfg.TLSAddr)
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s.wg.Add(1)
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go func() {
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defer s.wg.Done()
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for {
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conn, err := listener.Accept()
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if err != nil {
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return
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}
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s.wg.Add(1)
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go func() {
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defer s.wg.Done()
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s.handleConn(conn, port)
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}()
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}
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}()
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return nil
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}
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// parseAddrPort 从监听地址解析端口号，失败返回 0。
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func parseAddrPort(addr string) int {
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_, portStr, err := net.SplitHostPort(addr)
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if err != nil {
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return 0
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}
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port, err := strconv.Atoi(portStr)
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if err != nil {
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return 0
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}
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return port
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}
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// handleConn handles a single POP3 client connection.
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func (s *POP3Server) handleConn(conn net.Conn, port int) {
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defer conn.Close()
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conn.SetDeadline(time.Now().Add(10 * time.Minute))
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clientIP := store.ClientIPFromAddr(conn.RemoteAddr())
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startedAt := time.Now()
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// 已封禁 IP 直接拒绝（防协议层暴力破解）
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if banned, _ := s.stores.Bans.IsBanned(clientIP); banned {
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sendResponse(conn, "-ERR access denied")
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s.writeProtocolLog(port, clientIP, "", false, "IP已被封禁", "连接被拒绝", 0, 0, startedAt)
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return
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}
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// 会话状态（供协议日志汇总）
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var (
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authUser *db.User
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authUsername string
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authFailReason string
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commandCount = make(map[string]int)
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deletedCount int
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)
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reader := bufio.NewReader(conn)
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var messages []pop3Message
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var deleted map[int]bool
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tlsActive := false
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sendResponse(conn, "+OK MailGo POP3 server ready")
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for {
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line, err := reader.ReadString('\n')
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if err != nil {
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break
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}
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line = strings.TrimSpace(line)
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if line == "" {
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continue
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}
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parts := strings.SplitN(line, " ", 2)
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cmd := strings.ToUpper(parts[0])
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commandCount[cmd]++
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arg := ""
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if len(parts) > 1 {
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arg = strings.TrimSpace(parts[1])
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}
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authenticated := authUser != nil && authUser.ID != 0
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if !authenticated && requiresAuth(cmd) {
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sendResponse(conn, "-ERR authentication required")
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continue
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}
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switch cmd {
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case "USER":
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authUsername = arg
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authUser, messages, deleted = s.handleUSER(conn, arg, authUser)
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case "PASS":
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authUser, messages, deleted = s.handlePASS(conn, arg, authUser)
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if authUser == nil || authUser.ID == 0 {
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if authFailReason == "" {
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authFailReason = "用户名或密码错误"
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}
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} else {
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authFailReason = ""
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}
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case "STAT":
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s.handleSTAT(conn, messages, deleted)
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case "LIST":
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s.handleLIST(conn, arg, messages, deleted)
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case "RETR":
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s.handleRETR(conn, arg, messages, deleted)
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case "DELE":
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s.handleDELE(conn, arg, messages, deleted)
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case "NOOP":
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sendResponse(conn, "+OK")
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case "RSET":
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deleted = make(map[int]bool)
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sendResponse(conn, "+OK")
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case "QUIT":
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deletedCount = s.expungeDeleted(messages, deleted, authUser)
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sendResponse(conn, "+OK MailGo POP3 server signing off")
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s.writeProtocolLog(port, clientIP, authUsername, authUser != nil && authUser.ID != 0, authFailReason,
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pop3CommandDetail(commandCount, deletedCount), deletedCount,
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time.Since(startedAt).Milliseconds(), time.Now())
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return
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case "CAPA":
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s.handleCAPA(conn, tlsActive)
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case "STLS":
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if authenticated {
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sendResponse(conn, "-ERR STLS not allowed after authentication")
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continue
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}
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if tlsActive {
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sendResponse(conn, "-ERR TLS already active")
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continue
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}
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tlsConfig, err := s.tlsConfig()
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if err != nil {
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sendResponse(conn, "-ERR TLS not available")
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continue
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}
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sendResponse(conn, "+OK Begin TLS negotiation")
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tlsConn := tls.Server(conn, tlsConfig)
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if err := tlsConn.Handshake(); err != nil {
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s.writeProtocolLog(port, clientIP, authUsername, false, "TLS 握手失败",
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pop3CommandDetail(commandCount, 0), 0, time.Since(startedAt).Milliseconds(), time.Now())
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return
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}
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conn = tlsConn
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reader = bufio.NewReader(conn)
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tlsActive = true
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case "TOP":
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s.handleTOP(conn, arg, messages, deleted)
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case "UIDL":
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s.handleUIDL(conn, arg, messages, deleted)
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default:
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sendResponse(conn, "-ERR unknown command")
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}
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}
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// 连接异常结束（未 QUIT）
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success := authUser != nil && authUser.ID != 0 && authFailReason == ""
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if success && authFailReason == "" && authUsername == "" && len(commandCount) == 0 {
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success = true
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}
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s.writeProtocolLog(port, clientIP, authUsername, success, authFailReason,
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pop3CommandDetail(commandCount, 0), 0, time.Since(startedAt).Milliseconds(), time.Now())
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}
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// pop3CommandDetail 汇总会话中执行的命令为可读摘要（计数，忽略 NOOP/CAPA）。
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func pop3CommandDetail(counts map[string]int, deletedCount int) string {
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var parts []string
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for _, c := range []string{"USER", "PASS", "STAT", "LIST", "RETR", "TOP", "UIDL", "DELE", "RSET", "STLS", "QUIT"} {
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n := counts[c]
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if n == 0 {
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continue
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}
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if n == 1 {
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parts = append(parts, c)
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} else {
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parts = append(parts, fmt.Sprintf("%s×%d", c, n))
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}
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}
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if deletedCount > 0 {
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parts = append(parts, fmt.Sprintf("删除%d", deletedCount))
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}
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if len(parts) == 0 {
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return "连接建立，无命令"
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}
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return strings.Join(parts, " ")
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}
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// writeProtocolLog 写入一条 POP3 协议调用日志。
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func (s *POP3Server) writeProtocolLog(port int, ip, username string, success bool, failReason, detail string, msgCount int, durationMs int64, at time.Time) {
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entry := &db.ProtocolLog{
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Protocol: db.ProtocolPOP3,
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Port: port,
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ClientIP: ip,
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Username: username,
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Success: success,
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FailReason: failReason,
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Detail: detail,
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MsgCount: msgCount,
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DurationMs: durationMs,
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CreatedAt: at,
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}
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if err := s.stores.ProtocolLogs.Create(entry); err != nil {
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log.Printf("POP3: 写入协议日志失败: %v", err)
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}
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}
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func requiresAuth(cmd string) bool {
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switch cmd {
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case "STAT", "LIST", "RETR", "DELE", "RSET", "TOP", "UIDL":
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return true
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default:
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return false
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}
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}
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func (s *POP3Server) handleCAPA(conn net.Conn, tlsActive bool) {
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sendResponse(conn, "+OK Capability list follows")
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sendResponse(conn, "USER")
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sendResponse(conn, "TOP")
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sendResponse(conn, "UIDL")
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sendResponse(conn, "RESP-CODES")
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if !tlsActive && s.cfg.TLSCert != "" && s.cfg.TLSKey != "" {
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sendResponse(conn, "STLS")
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}
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sendResponse(conn, ".")
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}
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// pop3Message holds a message and its computed size for POP3.
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type pop3Message struct {
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id uint
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raw string
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size int
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message *db.Message
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}
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// loadMessages loads all INBOX messages for a user.
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func (s *POP3Server) loadMessages(user *db.User) []pop3Message {
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if user == nil {
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return nil
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}
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dbMsgs, err := s.stores.Mails.ListAllByUserAndFolder(user.ID, "INBOX")
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if err != nil {
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return nil
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}
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msgs := make([]pop3Message, 0, len(dbMsgs))
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for i := range dbMsgs {
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raw := string(buildRawMessage(&dbMsgs[i]))
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msgs = append(msgs, pop3Message{
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id: dbMsgs[i].ID,
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raw: raw,
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size: len(normalizePOP3Data(raw)),
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message: &dbMsgs[i],
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})
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}
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return msgs
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}
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// handleUSER processes the USER command.
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func (s *POP3Server) handleUSER(conn net.Conn, username string, currentUser *db.User) (*db.User, []pop3Message, map[int]bool) {
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if username == "" {
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sendResponse(conn, "-ERR missing username")
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return currentUser, nil, nil
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}
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user, err := s.stores.Users.GetByEmail(username)
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if err != nil {
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sendResponse(conn, "+OK")
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return &db.User{Username: username}, nil, nil
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}
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// 保留完整的邮箱地址作为登录标识（PASS 阶段用 Authenticate 校验），
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// user.ID 用于后续加载邮件。
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user.Username = username
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sendResponse(conn, "+OK")
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return user, nil, nil
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}
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// handlePASS processes the PASS command.
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func (s *POP3Server) handlePASS(conn net.Conn, password string, user *db.User) (*db.User, []pop3Message, map[int]bool) {
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if user == nil {
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sendResponse(conn, "-ERR no username given")
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return nil, nil, nil
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}
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clientIP := store.ClientIPFromAddr(conn.RemoteAddr())
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authUser, err := s.stores.Users.Authenticate(user.Username, password)
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if err != nil {
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// 认证失败计数，达到阈值按档位封禁（与 Web 登录共用 ban_entries）
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s.stores.RecordAuthFailure(clientIP, s.banCfg.MaxFailAttempts, s.banCfg.BanDurationMin, "邮件协议认证失败次数过多")
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sendResponse(conn, "-ERR authentication failed")
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return nil, nil, nil
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}
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messages := s.loadMessages(authUser)
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deleted := make(map[int]bool)
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sendResponse(conn, fmt.Sprintf("+OK authenticated, %d messages", len(messages)))
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return authUser, messages, deleted
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}
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// handleSTAT processes the STAT command.
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func (s *POP3Server) handleSTAT(conn net.Conn, messages []pop3Message, deleted map[int]bool) {
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count := 0
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totalSize := 0
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for i, msg := range messages {
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if !deleted[i+1] {
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count++
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totalSize += msg.size
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}
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}
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sendResponse(conn, fmt.Sprintf("+OK %d %d", count, totalSize))
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}
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// handleLIST processes the LIST command (with optional message number).
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func (s *POP3Server) handleLIST(conn net.Conn, arg string, messages []pop3Message, deleted map[int]bool) {
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if arg == "" {
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sendResponse(conn, "+OK message list follows")
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for i, msg := range messages {
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if !deleted[i+1] {
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sendResponse(conn, fmt.Sprintf("%d %d", i+1, msg.size))
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}
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}
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sendResponse(conn, ".")
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return
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}
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num, err := strconv.Atoi(arg)
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if err != nil || num < 1 || num > len(messages) {
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sendResponse(conn, "-ERR no such message")
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return
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}
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if deleted[num] {
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sendResponse(conn, "-ERR message deleted")
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return
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}
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sendResponse(conn, fmt.Sprintf("+OK %d %d", num, messages[num-1].size))
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}
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// handleRETR processes the RETR command.
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func (s *POP3Server) handleRETR(conn net.Conn, arg string, messages []pop3Message, deleted map[int]bool) {
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num, err := strconv.Atoi(arg)
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if err != nil || num < 1 || num > len(messages) {
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sendResponse(conn, "-ERR no such message")
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return
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}
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if deleted[num] {
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sendResponse(conn, "-ERR message deleted")
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return
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}
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msg := messages[num-1]
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sendResponse(conn, fmt.Sprintf("+OK %d octets", msg.size))
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writeDotStuffed(conn, msg.raw, nil)
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conn.Write([]byte(".\r\n"))
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}
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// handleDELE processes the DELE command.
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func (s *POP3Server) handleDELE(conn net.Conn, arg string, messages []pop3Message, deleted map[int]bool) {
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num, err := strconv.Atoi(arg)
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if err != nil || num < 1 || num > len(messages) {
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sendResponse(conn, "-ERR no such message")
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return
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}
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if deleted[num] {
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sendResponse(conn, "-ERR message already deleted")
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return
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}
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deleted[num] = true
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sendResponse(conn, "+OK message marked for deletion")
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}
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// handleTOP processes the TOP command (headers + first N lines of body).
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func (s *POP3Server) handleTOP(conn net.Conn, arg string, messages []pop3Message, deleted map[int]bool) {
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parts := strings.Fields(arg)
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if len(parts) < 1 {
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sendResponse(conn, "-ERR syntax error")
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return
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}
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num, err := strconv.Atoi(parts[0])
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if err != nil || num < 1 || num > len(messages) {
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sendResponse(conn, "-ERR no such message")
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return
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}
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if deleted[num] {
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sendResponse(conn, "-ERR message deleted")
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return
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}
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nLines := 0
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if len(parts) > 1 {
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nLines, _ = strconv.Atoi(parts[1])
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}
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msg := messages[num-1]
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header, body := splitHeaderBody(msg.raw)
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sendResponse(conn, "+OK top of message follows")
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writeDotStuffed(conn, header, nil)
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conn.Write([]byte("\r\n"))
|
||
writeDotStuffed(conn, body, &nLines)
|
||
conn.Write([]byte(".\r\n"))
|
||
}
|
||
|
||
// handleUIDL processes the UIDL command.
|
||
func (s *POP3Server) handleUIDL(conn net.Conn, arg string, messages []pop3Message, deleted map[int]bool) {
|
||
if arg == "" {
|
||
sendResponse(conn, "+OK UIDL list follows")
|
||
for i, msg := range messages {
|
||
if !deleted[i+1] {
|
||
sendResponse(conn, fmt.Sprintf("%d %d", i+1, msg.id))
|
||
}
|
||
}
|
||
sendResponse(conn, ".")
|
||
return
|
||
}
|
||
|
||
num, err := strconv.Atoi(arg)
|
||
if err != nil || num < 1 || num > len(messages) {
|
||
sendResponse(conn, "-ERR no such message")
|
||
return
|
||
}
|
||
if deleted[num] {
|
||
sendResponse(conn, "-ERR message deleted")
|
||
return
|
||
}
|
||
sendResponse(conn, fmt.Sprintf("+OK %d %d", num, messages[num-1].id))
|
||
}
|
||
|
||
// expungeDeleted actually deletes messages that were marked for deletion,
|
||
// returning the number of messages deleted.
|
||
func (s *POP3Server) expungeDeleted(messages []pop3Message, deleted map[int]bool, user *db.User) int {
|
||
if deleted == nil || user == nil || user.ID == 0 {
|
||
return 0
|
||
}
|
||
count := 0
|
||
for seqNum, msgDeleted := range deleted {
|
||
if msgDeleted && seqNum >= 1 && seqNum <= len(messages) {
|
||
if err := s.stores.Mails.Delete(messages[seqNum-1].id); err != nil {
|
||
log.Printf("POP3: failed to delete message %d: %v", messages[seqNum-1].id, err)
|
||
continue
|
||
}
|
||
count++
|
||
}
|
||
}
|
||
return count
|
||
}
|
||
|
||
// sendResponse writes a POP3 response line to the connection.
|
||
func sendResponse(conn net.Conn, line string) {
|
||
conn.Write([]byte(line + "\r\n"))
|
||
}
|
||
|
||
func normalizePOP3Data(raw string) string {
|
||
var b strings.Builder
|
||
writeDotStuffed(&b, raw, nil)
|
||
return b.String()
|
||
}
|
||
|
||
type stringWriter interface {
|
||
Write([]byte) (int, error)
|
||
}
|
||
|
||
func writeDotStuffed(w stringWriter, raw string, maxLines *int) {
|
||
raw = strings.ReplaceAll(raw, "\r\n", "\n")
|
||
raw = strings.ReplaceAll(raw, "\r", "\n")
|
||
lines := strings.Split(raw, "\n")
|
||
written := 0
|
||
for i, line := range lines {
|
||
if maxLines != nil && written >= *maxLines {
|
||
break
|
||
}
|
||
if i == len(lines)-1 && line == "" {
|
||
break
|
||
}
|
||
if strings.HasPrefix(line, ".") {
|
||
w.Write([]byte("."))
|
||
}
|
||
w.Write([]byte(line + "\r\n"))
|
||
written++
|
||
}
|
||
}
|
||
|
||
func splitHeaderBody(raw string) (string, string) {
|
||
if idx := strings.Index(raw, "\r\n\r\n"); idx >= 0 {
|
||
return raw[:idx], raw[idx+4:]
|
||
}
|
||
if idx := strings.Index(raw, "\n\n"); idx >= 0 {
|
||
return raw[:idx], raw[idx+2:]
|
||
}
|
||
return raw, ""
|
||
}
|
||
|
||
// buildRawMessage reconstructs a raw RFC822 message from a db.Message.
|
||
func buildRawMessage(msg *db.Message) []byte {
|
||
if msg.RawData != "" {
|
||
return []byte(msg.RawData)
|
||
}
|
||
|
||
var buf strings.Builder
|
||
buf.WriteString(fmt.Sprintf("From: %s\r\n", msg.FromAddr))
|
||
buf.WriteString(fmt.Sprintf("To: %s\r\n", msg.ToAddr))
|
||
if msg.CcAddr != "" {
|
||
buf.WriteString(fmt.Sprintf("Cc: %s\r\n", msg.CcAddr))
|
||
}
|
||
buf.WriteString(fmt.Sprintf("Subject: %s\r\n", msg.Subject))
|
||
buf.WriteString(fmt.Sprintf("Date: %s\r\n", msg.Date.Format("Mon, 02 Jan 2006 15:04:05 -0700")))
|
||
if msg.MessageID != "" {
|
||
buf.WriteString(fmt.Sprintf("Message-ID: %s\r\n", msg.MessageID))
|
||
}
|
||
buf.WriteString("MIME-Version: 1.0\r\n")
|
||
|
||
if msg.HtmlBody != "" && msg.TextBody != "" {
|
||
boundary := fmt.Sprintf("mailgo_%d", msg.ID)
|
||
buf.WriteString(fmt.Sprintf("Content-Type: multipart/alternative; boundary=\"%s\"\r\n", boundary))
|
||
buf.WriteString("\r\n")
|
||
buf.WriteString(fmt.Sprintf("--%s\r\n", boundary))
|
||
buf.WriteString("Content-Type: text/plain; charset=utf-8\r\n\r\n")
|
||
buf.WriteString(msg.TextBody)
|
||
buf.WriteString("\r\n")
|
||
buf.WriteString(fmt.Sprintf("--%s\r\n", boundary))
|
||
buf.WriteString("Content-Type: text/html; charset=utf-8\r\n\r\n")
|
||
buf.WriteString(msg.HtmlBody)
|
||
buf.WriteString("\r\n")
|
||
buf.WriteString(fmt.Sprintf("--%s--\r\n", boundary))
|
||
} else if msg.TextBody != "" {
|
||
buf.WriteString("Content-Type: text/plain; charset=utf-8\r\n\r\n")
|
||
buf.WriteString(msg.TextBody)
|
||
} else if msg.HtmlBody != "" {
|
||
buf.WriteString("Content-Type: text/html; charset=utf-8\r\n\r\n")
|
||
buf.WriteString(msg.HtmlBody)
|
||
} else {
|
||
buf.WriteString("Content-Type: text/plain; charset=utf-8\r\n\r\n")
|
||
}
|
||
return []byte(buf.String())
|
||
}
|