Other: add debug message dump when sending

internal/frontend/qt/frontend.go

@@ -733,4 +733,4 @@ func (s *FrontendQt) setKeychain(keychain string) {
 		s.restarter.SetToRestart()
 		s.App.Quit()
 	}
-}
+}

internal/smtp/dump_default.go

@@ -0,0 +1,22 @@
+// Copyright (c) 2021 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/>.
+
+// +build !build_qa
+
+package smtp
+
+func dumpMessageData([]byte, string) {}

internal/smtp/dump_qa.go

@@ -0,0 +1,60 @@
+// Copyright (c) 2021 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/>.
+
+// +build build_qa
+
+package smtp
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+func dumpMessageData(b []byte, subject string) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		logrus.WithError(err).Error("Failed to dump raw message data")
+		return
+	}
+
+	path := filepath.Join(home, "bridge-qa")
+
+	if err := os.MkdirAll(path, 0700); err != nil {
+		logrus.WithError(err).Error("Failed to dump raw message data")
+		return
+	}
+
+	if len(subject) > 16 {
+		subject = subject[:16]
+	}
+
+	if err := ioutil.WriteFile(
+		filepath.Join(path, fmt.Sprintf("%v-%v.eml", subject, time.Now().Format(time.RFC3339Nano))),
+		b,
+		0600,
+	); err != nil {
+		logrus.WithError(err).Error("Failed to dump raw message data")
+		return
+	}
+
+	logrus.WithField("path", path).Info("Dumped raw message data")
+}

internal/smtp/user.go

@@ -215,6 +215,10 @@ func (su *smtpUser) Send(returnPath string, to []string, messageReader io.Reader
 	// Called from go-smtp in goroutines - we need to handle panics for each function.
 	defer su.panicHandler.HandlePanic()
 
+	b := new(bytes.Buffer)
+
+	messageReader = io.TeeReader(messageReader, b)
+
 	mailSettings, err := su.client().GetMailSettings()
 	if err != nil {
 		return err
@@ -405,6 +409,8 @@ func (su *smtpUser) Send(returnPath string, to []string, messageReader io.Reader
 
 	req.PreparePackages()
 
+	dumpMessageData(b.Bytes(), message.Subject)
+
 	return su.storeUser.SendMessage(message.ID, req)
 }