Feature: SMTP STARTTLS & SMTP authentication support

Resolves #4

README.md

@@ -14,14 +14,15 @@ Mailpit is inspired by [MailHog](#why-rewrite-mailhog), but much, much faster.
 - Runs completely on a single binary
 - SMTP server (default `0.0.0.0:1025`)
 - Web UI to view emails (HTML format, text, source and MIME attachments, default `0.0.0.0:8025`)
-- Optional HTTPS for web UI ([see wiki](https://github.com/axllent/mailpit/wiki/HTTPS))
 - Real-time web UI updates using web sockets for new mail
-- Optional basic authentication for web UI ([see wiki](https://github.com/axllent/mailpit/wiki/Basic-authentication))
-- Email storage in either memory or disk (using [CloverDB](https://github.com/ostafen/clover)) - note that in-memory has a physical limit of 1MB per email
 - Configurable automatic email pruning (default keeps the most recent 500 emails)
+- Email storage either in memory or disk ([see wiki](https://github.com/axllent/mailpit/wiki/Email-storage))
 - Fast SMTP processing & storing - approximately 300-600 emails per second depending on CPU, network speed & email size
 - Can handle tens of thousands of emails
-- Multi-arch [Docker images](https://github.com/axllent/mailpit/wiki/Docker-images)
+- Optional SMTP with STARTTLS & SMTP authentication ([see wiki](https://github.com/axllent/mailpit/wiki/SMTP-with-STARTTLS-and-authentication))
+- Optional HTTPS for web UI ([see wiki](https://github.com/axllent/mailpit/wiki/HTTPS))
+- Optional basic authentication for web UI ([see wiki](https://github.com/axllent/mailpit/wiki/Basic-authentication))
+- Multi-architecture [Docker images](https://github.com/axllent/mailpit/wiki/Docker-images)
 
 
 ## Planned features
@@ -49,7 +50,7 @@ If Mailpit is found on the same host as sendmail, you can symlink the Mailpit bi
 
 You can use your default system `sendmail` binary to route directly to port `1025` (configurable) by calling `/usr/sbin/sendmail -S localhost:1025`.
 
-You can build a Mailpit-specific sendmail binary from source ( see [building from source](https://github.com/axllent/mailpit/wiki/Building-from-source)).
+You can build a Mailpit-specific sendmail binary from source (see [building from source](https://github.com/axllent/mailpit/wiki/Building-from-source)).
 
 
 ## Why rewrite MailHog?

cmd/root.go

@@ -85,21 +85,52 @@ func init() {
 		config.MaxMessages, _ = strconv.Atoi(os.Getenv("MP_MAX_MESSAGES"))
 	}
 	if len(os.Getenv("MP_AUTH_FILE")) > 0 {
-		config.AuthFile = os.Getenv("MP_AUTH_FILE")
+		config.UIAuthFile = os.Getenv("MP_AUTH_FILE")
 	}
+	if len(os.Getenv("MP_UI_AUTH_FILE")) > 0 {
+		config.UIAuthFile = os.Getenv("MP_UI_AUTH_FILE")
+	}
+	if len(os.Getenv("MP_SMTP_AUTH_FILE")) > 0 {
+		config.SMTPAuthFile = os.Getenv("MP_SMTP_AUTH_FILE")
+	}
+	// deprecated 2022/08/06
 	if len(os.Getenv("MP_SSL_CERT")) > 0 {
-		config.SSLCert = os.Getenv("MP_SSL_CERT")
+		config.UISSLCert = os.Getenv("MP_SSL_CERT")
 	}
+	// deprecated 2022/08/06
 	if len(os.Getenv("MP_SSL_KEY")) > 0 {
-		config.SSLKey = os.Getenv("MP_SSL_KEY")
+		config.UISSLKey = os.Getenv("MP_SSL_KEY")
+	}
+	if len(os.Getenv("MP_UI_SSL_CERT")) > 0 {
+		config.UISSLCert = os.Getenv("MP_UI_SSL_CERT")
+	}
+	if len(os.Getenv("MP_UISSL_KEY")) > 0 {
+		config.UISSLKey = os.Getenv("MP_UI_SSL_KEY")
 	}
 
 	rootCmd.Flags().StringVarP(&config.DataDir, "data", "d", config.DataDir, "Optional path to store peristent data")
 	rootCmd.Flags().StringVarP(&config.SMTPListen, "smtp", "s", config.SMTPListen, "SMTP bind interface and port")
 	rootCmd.Flags().StringVarP(&config.HTTPListen, "listen", "l", config.HTTPListen, "HTTP bind interface and port for UI")
 	rootCmd.Flags().IntVarP(&config.MaxMessages, "max", "m", config.MaxMessages, "Max number of messages to store")
-	rootCmd.Flags().StringVarP(&config.AuthFile, "auth-file", "a", config.AuthFile, "A password file for authentication (see wiki)")
-	rootCmd.Flags().StringVar(&config.SSLCert, "ssl-cert", config.SSLCert, "SSL certificate - requires ssl-key (see wiki)")
-	rootCmd.Flags().StringVar(&config.SSLKey, "ssl-key", config.SSLKey, "SSL key - requires ssl-cert (see wiki)")
+
+	rootCmd.Flags().StringVar(&config.UIAuthFile, "ui-auth-file", config.UIAuthFile, "A password file for web UI authentication")
+	rootCmd.Flags().StringVar(&config.UISSLCert, "ui-ssl-cert", config.UISSLCert, "SSL certificate for web UI - requires ui-ssl-key")
+	rootCmd.Flags().StringVar(&config.UISSLKey, "ui-ssl-key", config.UISSLKey, "SSL key for web UI - requires ui-ssl-cert")
+
+	rootCmd.Flags().StringVar(&config.SMTPAuthFile, "smtp-auth-file", config.SMTPAuthFile, "A password file for SMTP authentication")
+	rootCmd.Flags().StringVar(&config.SMTPSSLCert, "smtp-ssl-cert", config.SMTPSSLCert, "SSL certificate for SMTP - requires smtp-ssl-key")
+	rootCmd.Flags().StringVar(&config.SMTPSSLKey, "smtp-ssl-key", config.SMTPSSLKey, "SSL key for SMTP - requires smtp-ssl-cert")
+
 	rootCmd.Flags().BoolVarP(&config.VerboseLogging, "verbose", "v", false, "Verbose logging")
+
+	// deprecated 2022/08/06
+	rootCmd.Flags().StringVarP(&config.UIAuthFile, "auth-file", "a", config.UIAuthFile, "A password file for web UI authentication")
+	rootCmd.Flags().StringVar(&config.UISSLCert, "ssl-cert", config.UISSLCert, "SSL certificate - requires ssl-key")
+	rootCmd.Flags().StringVar(&config.UISSLKey, "ssl-key", config.UISSLKey, "SSL key - requires ssl-cert")
+	rootCmd.Flags().Lookup("auth-file").Hidden = true
+	rootCmd.Flags().Lookup("auth-file").Deprecated = "use --ui-auth-file"
+	rootCmd.Flags().Lookup("ssl-cert").Hidden = true
+	rootCmd.Flags().Lookup("ssl-cert").Deprecated = "use --ui-ssl-cert"
+	rootCmd.Flags().Lookup("ssl-key").Hidden = true
+	rootCmd.Flags().Lookup("ssl-key").Deprecated = "use --ui-ssl-key"
 }

config/config.go

@@ -28,17 +28,29 @@ var (
 	// NoLogging for tests
 	NoLogging = false
 
-	// SSLCert file
-	SSLCert string
+	// UISSLCert file
+	UISSLCert string
 
-	// SSLKey file
-	SSLKey string
+	// UISSLKey file
+	UISSLKey string
 
-	// AuthFile for basic authentication
-	AuthFile string
+	// UIAuthFile for basic authentication
+	UIAuthFile string
 
-	// Auth used for euthentication
-	Auth *htpasswd.File
+	// UIAuth used for euthentication
+	UIAuth *htpasswd.File
+
+	// SMTPSSLCert file
+	SMTPSSLCert string
+
+	// SMTPSSLKey file
+	SMTPSSLKey string
+
+	// SMTPAuthFile for SMTP authentication
+	SMTPAuthFile string
+
+	// SMTPAuth used for euthentication
+	SMTPAuth *htpasswd.File
 )
 
 // VerifyConfig wil do some basic checking
@@ -51,30 +63,60 @@ func VerifyConfig() error {
 		return errors.New("HTTP bind should be in the format of <ip>:<port>")
 	}
 
-	if AuthFile != "" {
-		if !isFile(AuthFile) {
-			return fmt.Errorf("password file not found: %s", AuthFile)
+	if UIAuthFile != "" {
+		if !isFile(UIAuthFile) {
+			return fmt.Errorf("HTTP password file not found: %s", UIAuthFile)
 		}
 
-		a, err := htpasswd.New(AuthFile, htpasswd.DefaultSystems, nil)
+		a, err := htpasswd.New(UIAuthFile, htpasswd.DefaultSystems, nil)
 		if err != nil {
 			return err
 		}
-		Auth = a
+		UIAuth = a
+	}
+
+	if UISSLCert != "" && UISSLKey == "" || UISSLCert == "" && UISSLKey != "" {
+		return errors.New("you must provide both a UI SSL certificate and a key")
+	}
+
+	if UISSLCert != "" {
+		if !isFile(UISSLCert) {
+			return fmt.Errorf("SSL certificate not found: %s", UISSLCert)
+		}
+
+		if !isFile(UISSLKey) {
+			return fmt.Errorf("SSL key not found: %s", UISSLKey)
+		}
+	}
+
+	if SMTPSSLCert != "" && SMTPSSLKey == "" || SMTPSSLCert == "" && SMTPSSLKey != "" {
+		return errors.New("you must provide both an SMTP SSL certificate and a key")
 	}
 
-	if SSLCert != "" && SSLKey == "" || SSLCert == "" && SSLKey != "" {
-		return errors.New("you must provide both an SSL certificate and a key")
+	if SMTPSSLCert != "" {
+		if !isFile(SMTPSSLCert) {
+			return fmt.Errorf("SMTP SSL certificate not found: %s", SMTPSSLCert)
+		}
+
+		if !isFile(SMTPSSLKey) {
+			return fmt.Errorf("SMTP SSL key not found: %s", SMTPSSLKey)
+		}
 	}
 
-	if SSLCert != "" {
-		if !isFile(SSLCert) {
-			return fmt.Errorf("SSL certificate not found: %s", SSLCert)
+	if SMTPAuthFile != "" {
+		if !isFile(SMTPAuthFile) {
+			return fmt.Errorf("SMTP password file not found: %s", SMTPAuthFile)
+		}
+
+		if SMTPSSLCert == "" {
+			return errors.New("SMTP authentication requires SMTP encryption")
 		}
 
-		if !isFile(SSLKey) {
-			return fmt.Errorf("SSL key not found: %s", SSLKey)
+		a, err := htpasswd.New(SMTPAuthFile, htpasswd.DefaultSystems, nil)
+		if err != nil {
+			return err
 		}
+		SMTPAuth = a
 	}
 
 	return nil

server/server.go

@@ -47,9 +47,13 @@ func Listen() {
 	r.PathPrefix("/").Handler(middlewareHandler(http.FileServer(http.FS(serverRoot))))
 	http.Handle("/", r)
 
-	if config.SSLCert != "" && config.SSLKey != "" {
+	if config.UIAuthFile != "" {
+		logger.Log().Info("[http] enabling web UI basic authentication")
+	}
+
+	if config.UISSLCert != "" && config.UISSLKey != "" {
 		logger.Log().Infof("[http] starting secure server on https://%s", config.HTTPListen)
-		log.Fatal(http.ListenAndServeTLS(config.HTTPListen, config.SSLCert, config.SSLKey, nil))
+		log.Fatal(http.ListenAndServeTLS(config.HTTPListen, config.UISSLCert, config.UISSLKey, nil))
 	} else {
 		logger.Log().Infof("[http] starting server on http://%s", config.HTTPListen)
 		log.Fatal(http.ListenAndServe(config.HTTPListen, nil))
@@ -76,15 +80,15 @@ func (w gzipResponseWriter) Write(b []byte) (int, error) {
 // and gzip compression.
 func middleWareFunc(fn http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		if config.AuthFile != "" {
+		if config.UIAuthFile != "" {
 			user, pass, ok := r.BasicAuth()
 
 			if !ok {
 				basicAuthResponse(w)
 				return
 			}
 
-			if !config.Auth.Match(user, pass) {
+			if !config.UIAuth.Match(user, pass) {
 				basicAuthResponse(w)
 				return
 			}
@@ -107,15 +111,15 @@ func middleWareFunc(fn http.HandlerFunc) http.HandlerFunc {
 func middlewareHandler(h http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 
-		if config.AuthFile != "" {
+		if config.UIAuthFile != "" {
 			user, pass, ok := r.BasicAuth()
 
 			if !ok {
 				basicAuthResponse(w)
 				return
 			}
 
-			if !config.Auth.Match(user, pass) {
+			if !config.UIAuth.Match(user, pass) {
 				basicAuthResponse(w)
 				return
 			}

server/websockets/client.go

@@ -99,16 +99,16 @@ func (c *Client) writePump() {
 
 // ServeWs handles websocket requests from the peer.
 func ServeWs(hub *Hub, w http.ResponseWriter, r *http.Request) {
-	if config.AuthFile != "" {
-		if config.AuthFile != "" {
+	if config.UIAuthFile != "" {
+		if config.UIAuthFile != "" {
 			user, pass, ok := r.BasicAuth()
 
 			if !ok {
 				basicAuthResponse(w)
 				return
 			}
 
-			if !config.Auth.Match(user, pass) {
+			if !config.UIAuth.Match(user, pass) {
 				basicAuthResponse(w)
 				return
 			}

smtpd/smtpd.go

@@ -9,7 +9,7 @@ import (
 	"github.com/axllent/mailpit/config"
 	"github.com/axllent/mailpit/logger"
 	"github.com/axllent/mailpit/storage"
-	s "github.com/mhale/smtpd"
+	"github.com/mhale/smtpd"
 )
 
 func mailHandler(origin net.Addr, from string, to []string, data []byte) error {
@@ -37,12 +37,45 @@ func mailHandler(origin net.Addr, from string, to []string, data []byte) error {
 	return nil
 }
 
+func authHandler(remoteAddr net.Addr, mechanism string, username []byte, password []byte, shared []byte) (bool, error) {
+	return config.SMTPAuth.Match(string(username), string(password)), nil
+}
+
 // Listen starts the SMTPD server
 func Listen() error {
+	if config.SMTPSSLCert != "" {
+		logger.Log().Info("[smtp] enabling TLS")
+	}
+	if config.SMTPAuthFile != "" {
+		logger.Log().Info("[smtp] enabling authentication")
+	}
+
 	logger.Log().Infof("[smtp] starting on %s", config.SMTPListen)
-	if err := s.ListenAndServe(config.SMTPListen, mailHandler, "Mailpit", ""); err != nil {
-		return err
+
+	return listenAndServe(config.SMTPListen, mailHandler, authHandler)
+}
+
+func listenAndServe(addr string, handler smtpd.Handler, authHandler smtpd.AuthHandler) error {
+	srv := &smtpd.Server{
+		Addr:         addr,
+		Handler:      handler,
+		Appname:      "Mailpit",
+		Hostname:     "",
+		AuthHandler:  nil,
+		AuthRequired: false,
 	}
 
-	return nil
+	if config.SMTPAuthFile != "" {
+		srv.AuthHandler = authHandler
+		srv.AuthRequired = true
+	}
+
+	if config.SMTPSSLCert != "" {
+		err := srv.ConfigureTLS(config.SMTPSSLCert, config.SMTPSSLKey)
+		if err != nil {
+			return err
+		}
+	}
+
+	return srv.ListenAndServe()
 }