GODT-1779: Remove go-imap

internal/bridge/smtp.go

@@ -0,0 +1,109 @@
+package bridge
+
+import (
+	"crypto/tls"
+	"fmt"
+
+	"github.com/ProtonMail/proton-bridge/v2/internal/constants"
+	"github.com/emersion/go-sasl"
+	"github.com/emersion/go-smtp"
+	"github.com/sirupsen/logrus"
+)
+
+func (bridge *Bridge) GetSMTPPort() int {
+	return bridge.vault.GetSMTPPort()
+}
+
+func (bridge *Bridge) SetSMTPPort(newPort int) error {
+	if newPort == bridge.vault.GetSMTPPort() {
+		return nil
+	}
+
+	if err := bridge.vault.SetSMTPPort(newPort); err != nil {
+		return err
+	}
+
+	return bridge.restartSMTP()
+}
+
+func (bridge *Bridge) GetSMTPSSL() bool {
+	return bridge.vault.GetSMTPSSL()
+}
+
+func (bridge *Bridge) SetSMTPSSL(newSSL bool) error {
+	if newSSL == bridge.vault.GetSMTPSSL() {
+		return nil
+	}
+
+	if err := bridge.vault.SetSMTPSSL(newSSL); err != nil {
+		return err
+	}
+
+	return bridge.restartSMTP()
+}
+
+func (bridge *Bridge) serveSMTP() error {
+	smtpListener, err := newListener(bridge.vault.GetSMTPPort(), bridge.vault.GetSMTPSSL(), bridge.tlsConfig)
+	if err != nil {
+		return fmt.Errorf("failed to create SMTP listener: %w", err)
+	}
+
+	bridge.smtpListener = smtpListener
+
+	go func() {
+		if err := bridge.smtpServer.Serve(bridge.smtpListener); err != nil {
+			logrus.WithError(err).Error("SMTP server stopped")
+		}
+	}()
+
+	return nil
+}
+
+func (bridge *Bridge) restartSMTP() error {
+	if err := bridge.closeSMTP(); err != nil {
+		return err
+	}
+
+	smtpServer, err := newSMTPServer(bridge.smtpBackend, bridge.tlsConfig)
+	if err != nil {
+		return err
+	}
+
+	bridge.smtpServer = smtpServer
+
+	return bridge.serveSMTP()
+}
+
+func (bridge *Bridge) closeSMTP() error {
+	if err := bridge.smtpServer.Close(); err != nil {
+		logrus.WithError(err).Warn("Failed to close SMTP server")
+	}
+
+	// Don't close the SMTP listener -- it's closed by the server.
+
+	return nil
+}
+
+func newSMTPServer(smtpBackend *smtpBackend, tlsConfig *tls.Config) (*smtp.Server, error) {
+	smtpServer := smtp.NewServer(smtpBackend)
+
+	smtpServer.TLSConfig = tlsConfig
+	smtpServer.Domain = constants.Host
+	smtpServer.AllowInsecureAuth = true
+	smtpServer.MaxLineLength = 1 << 16
+
+	smtpServer.EnableAuth(sasl.Login, func(conn *smtp.Conn) sasl.Server {
+		return sasl.NewLoginServer(func(address, password string) error {
+			user, err := conn.Server().Backend.Login(nil, address, password)
+			if err != nil {
+				return err
+			}
+
+			conn.SetSession(user)
+
+			return nil
+		})
+	})
+
+	return smtpServer, nil
+}