mirror of
https://github.com/shadow1ng/fscan.git
synced 2026-09-22 03:10:42 +08:00
NOPTrace
6bb8ccd490
testAnonymousAccess and testOpenRelay dial the target and immediately hand the connection to smtp.NewClient without setting any deadline. smtp.NewClient reads the 220 greeting as its first operation, so a server that accepts TCP but never sends data (honeypot/tarpit) blocks the goroutine forever. The outer select waits on resultChan or ctx.Done(); with the default -gt 0 the context has no deadline, so Scan never returns and RunScan's wg.Wait() freezes the whole process. Set the same ModuleTimeout deadline used by the other functions in this file (doSMTPAuth, testVRFYCommand, testEXPNCommand, getServerInfo). Verified against a live accept-but-silent SMTP endpoint: - unpatched: process hangs (31 goroutines, stack at smtp.go:276) - patched: full plugin chain completes in ~92s, no regression on normally-responding servers (detection output identical)
560 lines
13 KiB
Go
560 lines
13 KiB
Go
//go:build plugin_smtp || !plugin_selective
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package services
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import (
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"context"
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"fmt"
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"net/smtp"
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"strings"
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"time"
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"github.com/shadow1ng/fscan/common"
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"github.com/shadow1ng/fscan/common/i18n"
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"github.com/shadow1ng/fscan/plugins"
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)
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// SMTPPlugin SMTP扫描插件
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type SMTPPlugin struct {
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plugins.BasePlugin
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}
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func NewSMTPPlugin() *SMTPPlugin {
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return &SMTPPlugin{
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BasePlugin: plugins.NewBasePlugin("smtp"),
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}
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}
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func (p *SMTPPlugin) Scan(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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config := session.Config
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target := info.Target()
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if config.DisableBrute {
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return p.identifyService(ctx, info, session)
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}
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// 检测未授权访问
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if result := p.testUnauthorizedAccess(ctx, info, session); result != nil && result.Success {
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session.LogSuccess(i18n.Tr("smtp_service", target, result.Banner))
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return result
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}
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// 生成密码字典
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credentials := plugins.GenerateCredentials("smtp", config)
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if len(credentials) == 0 {
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return &ScanResult{
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Success: false,
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Service: "smtp",
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Error: fmt.Errorf("%s", i18n.GetText("service_no_credentials")),
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}
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}
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// 转换凭据类型
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creds := make([]Credential, len(credentials))
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for i, c := range credentials {
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creds[i] = Credential{Username: c.Username, Password: c.Password}
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}
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// 使用公共框架进行并发凭据测试
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authFn := p.createAuthFunc(info, session)
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testConfig := DefaultConcurrentTestConfigWithTarget(config, info)
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result := TestCredentialsConcurrently(ctx, creds, authFn, "smtp", testConfig)
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if result.Success {
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session.LogVuln(i18n.Tr("smtp_credential", target, result.Username, result.Password))
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}
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return result
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}
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// createAuthFunc 创建SMTP认证函数
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func (p *SMTPPlugin) createAuthFunc(info *common.HostInfo, session *common.ScanSession) AuthFunc {
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return func(ctx context.Context, cred Credential) *AuthResult {
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return p.doSMTPAuth(ctx, info, cred, session)
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}
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}
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// doSMTPAuth 执行SMTP认证
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func (p *SMTPPlugin) doSMTPAuth(ctx context.Context, info *common.HostInfo, cred Credential, session *common.ScanSession) *AuthResult {
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target := info.Target()
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timeout := session.Config.ModuleTimeout()
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resultChan := make(chan *AuthResult, 1)
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go func() {
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conn, err := session.DialTCP(ctx, "tcp", target, timeout)
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if err != nil {
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resultChan <- &AuthResult{
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Success: false,
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ErrorType: classifySMTPErrorType(err),
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Error: err,
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}
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return
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}
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_ = conn.SetDeadline(time.Now().Add(timeout))
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client, err := smtp.NewClient(conn, info.Host)
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if err != nil {
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_ = conn.Close()
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resultChan <- &AuthResult{
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Success: false,
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ErrorType: classifySMTPErrorType(err),
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Error: err,
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}
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return
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}
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if cred.Username != "" {
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auth := smtp.PlainAuth("", cred.Username, cred.Password, info.Host)
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if err := client.Auth(auth); err != nil {
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_ = client.Close()
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resultChan <- &AuthResult{
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Success: false,
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ErrorType: classifySMTPErrorType(err),
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Error: err,
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}
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return
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}
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}
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if err := client.Mail("[email protected]"); err != nil {
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_ = client.Close()
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resultChan <- &AuthResult{
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Success: false,
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ErrorType: classifySMTPErrorType(err),
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Error: err,
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}
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return
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}
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resultChan <- &AuthResult{
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Success: true,
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Conn: &smtpClientWrapper{client},
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ErrorType: ErrorTypeUnknown,
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Error: nil,
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}
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}()
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select {
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case result := <-resultChan:
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return result
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case <-ctx.Done():
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// context 被取消，启动清理协程等待并关闭可能创建的连接
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go func() {
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result := <-resultChan
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if result != nil && result.Conn != nil {
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_ = result.Conn.Close()
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}
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}()
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return &AuthResult{
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Success: false,
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ErrorType: ErrorTypeNetwork,
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Error: ctx.Err(),
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}
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}
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}
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// smtpClientWrapper 包装SMTP客户端以实现io.Closer
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type smtpClientWrapper struct {
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client *smtp.Client
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}
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func (w *smtpClientWrapper) Close() error {
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return w.client.Close()
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}
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// classifySMTPErrorType SMTP错误分类
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func classifySMTPErrorType(err error) ErrorType {
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if err == nil {
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return ErrorTypeUnknown
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}
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smtpAuthErrors := []string{
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"authentication failed",
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"authentication failure",
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"auth failed",
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"login failed",
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"invalid credentials",
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"invalid username or password",
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"username or password incorrect",
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"password incorrect",
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"access denied",
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"permission denied",
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"unauthorized",
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"not authorized",
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"authentication required",
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"535 authentication failed",
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"535 incorrect authentication",
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"535 invalid credentials",
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"535 authentication credentials invalid",
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"534 authentication mechanism is too weak",
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"530 authentication required",
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"530 must authenticate",
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"451 authentication aborted",
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"bad username or password",
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"invalid user",
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"user unknown",
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"mailbox unavailable",
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"relay access denied",
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"relay not permitted",
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}
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return ClassifyError(err, smtpAuthErrors, CommonNetworkErrors)
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}
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// testUnauthorizedAccess 测试SMTP未授权访问
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func (p *SMTPPlugin) testUnauthorizedAccess(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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// 测试匿名访问
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if result := p.testAnonymousAccess(ctx, info, session); result != nil {
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return result
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}
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// 测试开放中继
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if result := p.testOpenRelay(ctx, info, session); result != nil {
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return result
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}
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// 测试VRFY命令
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if result := p.testVRFYCommand(ctx, info, session); result != nil {
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return result
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}
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// 测试EXPN命令
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if result := p.testEXPNCommand(ctx, info, session); result != nil {
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return result
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}
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return nil
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}
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// testAnonymousAccess 测试匿名邮件发送
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func (p *SMTPPlugin) testAnonymousAccess(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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target := info.Target()
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resultChan := make(chan *ScanResult, 1)
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go func() {
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conn, err := session.DialTCP(ctx, "tcp", target, session.Config.ModuleTimeout())
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if err != nil {
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resultChan <- nil
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return
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}
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defer func() { _ = conn.Close() }()
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// 修复: 设置读写超时, 防止对只accept不发送banner的服务器(tarpit)永久阻塞
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_ = conn.SetDeadline(time.Now().Add(session.Config.ModuleTimeout()))
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client, err := smtp.NewClient(conn, info.Host)
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if err != nil {
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resultChan <- nil
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return
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}
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defer func() { _ = client.Quit() }()
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if err := client.Hello("fscan.test"); err != nil {
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resultChan <- nil
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return
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}
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if err := client.Mail("[email protected]"); err != nil {
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resultChan <- nil
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return
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}
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if err := client.Rcpt("[email protected]"); err != nil {
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resultChan <- nil
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return
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}
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resultChan <- &ScanResult{
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Success: true,
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Type: plugins.ResultTypeVuln,
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Service: "smtp",
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Banner: i18n.GetText("smtp_anonymous_mail_allowed"),
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}
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}()
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select {
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case result := <-resultChan:
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return result
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case <-ctx.Done():
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return nil
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}
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}
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// testOpenRelay 测试开放中继
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func (p *SMTPPlugin) testOpenRelay(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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target := info.Target()
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resultChan := make(chan *ScanResult, 1)
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go func() {
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conn, err := session.DialTCP(ctx, "tcp", target, session.Config.ModuleTimeout())
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if err != nil {
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resultChan <- nil
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return
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}
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defer func() { _ = conn.Close() }()
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// 修复: 设置读写超时, 防止对只accept不发送banner的服务器(tarpit)永久阻塞
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_ = conn.SetDeadline(time.Now().Add(session.Config.ModuleTimeout()))
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client, err := smtp.NewClient(conn, info.Host)
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if err != nil {
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resultChan <- nil
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return
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}
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defer func() { _ = client.Quit() }()
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if err := client.Hello("fscan.test"); err != nil {
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resultChan <- nil
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return
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}
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if err := client.Mail("[email protected]"); err != nil {
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resultChan <- nil
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return
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}
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if err := client.Rcpt("[email protected]"); err != nil {
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resultChan <- nil
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return
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}
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resultChan <- &ScanResult{
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Success: true,
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Type: plugins.ResultTypeVuln,
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Service: "smtp",
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Banner: i18n.GetText("smtp_open_relay"),
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}
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}()
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select {
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case result := <-resultChan:
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return result
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case <-ctx.Done():
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return nil
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}
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}
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// testVRFYCommand 测试VRFY命令用户枚举
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func (p *SMTPPlugin) testVRFYCommand(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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target := info.Target()
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resultChan := make(chan *ScanResult, 1)
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go func() {
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conn, err := session.DialTCP(ctx, "tcp", target, session.Config.ModuleTimeout())
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if err != nil {
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resultChan <- nil
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return
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}
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defer func() { _ = conn.Close() }()
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_ = conn.SetDeadline(time.Now().Add(session.Config.ModuleTimeout()))
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if _, heloWriteErr := fmt.Fprintf(conn, "HELO fscan.test\r\n"); heloWriteErr != nil {
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resultChan <- nil
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return
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}
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buffer := make([]byte, 1024)
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n, err := conn.Read(buffer)
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if err != nil {
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resultChan <- nil
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return
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}
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response := string(buffer[:n])
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if !strings.HasPrefix(response, "250") {
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resultChan <- nil
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return
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}
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testUsers := []string{"admin", "root", "test", "user", "postmaster", "administrator"}
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for _, user := range testUsers {
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if _, err := fmt.Fprintf(conn, "VRFY %s\r\n", user); err != nil {
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continue
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}
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n, err := conn.Read(buffer)
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if err != nil {
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continue
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}
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vrfyResponse := strings.TrimSpace(string(buffer[:n]))
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if strings.HasPrefix(vrfyResponse, "250") {
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resultChan <- &ScanResult{
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Success: true,
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Type: plugins.ResultTypeVuln,
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Service: "smtp",
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Banner: i18n.Tr("smtp_vrfy_user_enum", user),
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}
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return
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}
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}
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resultChan <- nil
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}()
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select {
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case result := <-resultChan:
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return result
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case <-ctx.Done():
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return nil
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}
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}
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// testEXPNCommand 测试EXPN命令邮件列表枚举
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func (p *SMTPPlugin) testEXPNCommand(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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target := info.Target()
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resultChan := make(chan *ScanResult, 1)
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go func() {
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conn, err := session.DialTCP(ctx, "tcp", target, session.Config.ModuleTimeout())
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if err != nil {
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resultChan <- nil
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return
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}
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defer func() { _ = conn.Close() }()
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_ = conn.SetDeadline(time.Now().Add(session.Config.ModuleTimeout()))
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if _, heloWriteErr := fmt.Fprintf(conn, "HELO fscan.test\r\n"); heloWriteErr != nil {
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resultChan <- nil
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return
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}
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buffer := make([]byte, 1024)
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n, err := conn.Read(buffer)
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if err != nil {
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resultChan <- nil
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return
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}
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response := string(buffer[:n])
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if !strings.HasPrefix(response, "250") {
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resultChan <- nil
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return
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}
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testLists := []string{"all", "staff", "users", "admin", "everyone", "postmaster"}
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for _, list := range testLists {
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if _, err := fmt.Fprintf(conn, "EXPN %s\r\n", list); err != nil {
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continue
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}
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n, err := conn.Read(buffer)
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if err != nil {
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continue
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}
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expnResponse := strings.TrimSpace(string(buffer[:n]))
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if strings.HasPrefix(expnResponse, "250") {
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resultChan <- &ScanResult{
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Success: true,
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Type: plugins.ResultTypeVuln,
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Service: "smtp",
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Banner: i18n.Tr("smtp_expn_list_enum", list),
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}
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return
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}
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}
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resultChan <- nil
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}()
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select {
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case result := <-resultChan:
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return result
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case <-ctx.Done():
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return nil
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}
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}
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// getServerInfo 获取SMTP服务器信息
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func (p *SMTPPlugin) getServerInfo(ctx context.Context, info *common.HostInfo, session *common.ScanSession) string {
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target := info.Target()
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resultChan := make(chan string, 1)
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go func() {
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conn, err := session.DialTCP(ctx, "tcp", target, session.Config.ModuleTimeout())
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if err != nil {
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resultChan <- ""
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return
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}
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defer func() { _ = conn.Close() }()
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_ = conn.SetReadDeadline(time.Now().Add(session.Config.ModuleTimeout()))
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buffer := make([]byte, 1024)
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n, err := conn.Read(buffer)
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if err != nil {
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resultChan <- ""
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return
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}
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welcome := strings.TrimSpace(string(buffer[:n]))
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if strings.HasPrefix(welcome, "220") {
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serverInfo := strings.TrimPrefix(welcome, "220 ")
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resultChan <- serverInfo
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return
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}
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resultChan <- welcome
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}()
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select {
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case result := <-resultChan:
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return result
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case <-ctx.Done():
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return ""
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}
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}
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// identifyService SMTP服务识别
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func (p *SMTPPlugin) identifyService(ctx context.Context, info *common.HostInfo, session *common.ScanSession) *ScanResult {
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target := info.Target()
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serverInfo := p.getServerInfo(ctx, info, session)
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var banner string
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if serverInfo != "" {
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banner = i18n.Tr("smtp_mail_service_info", serverInfo)
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} else {
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conn, err := session.DialTCP(ctx, "tcp", target, session.Config.ModuleTimeout())
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if err != nil {
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return &ScanResult{
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Success: false,
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Service: "smtp",
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Error: err,
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}
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}
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defer func() { _ = conn.Close() }()
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banner = i18n.GetText("smtp_mail_service")
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}
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session.LogSuccess(i18n.Tr("smtp_service", target, banner))
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return &ScanResult{
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Success: true,
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Type: plugins.ResultTypeService,
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Service: "smtp",
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Banner: banner,
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}
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}
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func init() {
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RegisterPluginWithPorts("smtp", func() Plugin {
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return NewSMTPPlugin()
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}, []int{25, 465, 587, 2525})
|
|
}
|