Files
proton-bridge/internal/smtp/backend.go
2020-11-27 09:23:18 +01:00

120 lines
3.9 KiB
Go

// Copyright (c) 2020 Proton Technologies AG
//
// This file is part of ProtonMail Bridge.
//
// ProtonMail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// ProtonMail Bridge is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with ProtonMail Bridge. If not, see <https://www.gnu.org/licenses/>.
package smtp
import (
"strings"
"time"
"github.com/ProtonMail/proton-bridge/internal/bridge"
"github.com/ProtonMail/proton-bridge/internal/preferences"
"github.com/ProtonMail/proton-bridge/pkg/config"
"github.com/ProtonMail/proton-bridge/pkg/confirmer"
"github.com/ProtonMail/proton-bridge/pkg/listener"
goSMTPBackend "github.com/emersion/go-smtp"
"github.com/pkg/errors"
"github.com/sirupsen/logrus"
)
type panicHandler interface {
HandlePanic()
}
type smtpBackend struct {
panicHandler panicHandler
eventListener listener.Listener
preferences *config.Preferences
bridge bridger
confirmer *confirmer.Confirmer
sendRecorder *sendRecorder
}
// NewSMTPBackend returns struct implementing go-smtp/backend interface.
func NewSMTPBackend(
panicHandler panicHandler,
eventListener listener.Listener,
preferences *config.Preferences,
bridge *bridge.Bridge,
) *smtpBackend { //nolint[golint]
return newSMTPBackend(panicHandler, eventListener, preferences, newBridgeWrap(bridge))
}
func newSMTPBackend(
panicHandler panicHandler,
eventListener listener.Listener,
preferences *config.Preferences,
bridge bridger,
) *smtpBackend {
return &smtpBackend{
panicHandler: panicHandler,
eventListener: eventListener,
preferences: preferences,
bridge: bridge,
confirmer: confirmer.New(),
sendRecorder: newSendRecorder(),
}
}
// Login authenticates a user.
func (sb *smtpBackend) Login(_ *goSMTPBackend.ConnectionState, username, password string) (goSMTPBackend.Session, error) {
// Called from go-smtp in goroutines - we need to handle panics for each function.
defer sb.panicHandler.HandlePanic()
username = strings.ToLower(username)
user, err := sb.bridge.GetUser(username)
if err != nil {
log.Warn("Cannot get user: ", err)
return nil, err
}
if err := user.CheckBridgeLogin(password); err != nil {
log.WithError(err).Error("Could not check bridge password")
// Apple Mail sometimes generates a lot of requests very quickly. It's good practice
// to have a timeout after bad logins so that we can slow those requests down a little bit.
time.Sleep(10 * time.Second)
return nil, err
}
// Client can log in only using address so we can properly close all SMTP connections.
addressID, err := user.GetAddressID(username)
if err != nil {
log.Error("Cannot get addressID: ", err)
return nil, err
}
// AddressID is only for split mode--it has to be empty for combined mode.
if user.IsCombinedAddressMode() {
addressID = ""
}
return newSMTPUser(sb.panicHandler, sb.eventListener, sb, user, username, addressID)
}
func (sb *smtpBackend) AnonymousLogin(_ *goSMTPBackend.ConnectionState) (goSMTPBackend.Session, error) {
// Called from go-smtp in goroutines - we need to handle panics for each function.
defer sb.panicHandler.HandlePanic()
return nil, errors.New("anonymous login not supported")
}
func (sb *smtpBackend) shouldReportOutgoingNoEnc() bool {
return sb.preferences.GetBool(preferences.ReportOutgoingNoEncKey)
}
func (sb *smtpBackend) ConfirmNoEncryption(messageID string, shouldSend bool) {
if err := sb.confirmer.SetResult(messageID, shouldSend); err != nil {
logrus.WithError(err).Error("Failed to set confirmation value")
}
}