proton-bridge/pkg/message/build_custom.go

98 lines
2.5 KiB
Go

// Copyright (c) 2024 Proton AG
//
// This file is part of Proton Mail Bridge.
//
// Proton Mail 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.
//
// Proton Mail 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 Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
package message
import (
"fmt"
"mime"
"github.com/ProtonMail/go-proton-api"
"github.com/ProtonMail/gopenpgp/v2/constants"
"github.com/ProtonMail/gopenpgp/v2/crypto"
"github.com/emersion/go-message"
)
// writeCustomTextPart writes an armored-PGP text part for a message body that couldn't be decrypted.
func writeCustomTextPart(
w *message.Writer,
decrypted *DecryptedMessage,
decError error,
) error {
enc, err := crypto.NewPGPMessageFromArmored(decrypted.Msg.Body)
if err != nil {
return err
}
arm, err := enc.GetArmoredWithCustomHeaders(
fmt.Sprintf("This message could not be decrypted: %v", decError),
constants.ArmorHeaderVersion,
)
if err != nil {
return err
}
var hdr message.Header
hdr.SetContentType(string(decrypted.Msg.MIMEType), nil)
part, err := w.CreatePart(hdr)
if err != nil {
return err
}
if _, err := part.Write([]byte(arm)); err != nil {
return err
}
return nil
}
// writeCustomAttachmentPart writes an armored-PGP data part for an attachment that couldn't be decrypted.
func writeCustomAttachmentPart(
w *message.Writer,
att proton.Attachment,
msg *crypto.PGPMessage,
decError error,
) error {
arm, err := msg.GetArmoredWithCustomHeaders(
fmt.Sprintf("This attachment could not be decrypted: %v", decError),
constants.ArmorHeaderVersion,
)
if err != nil {
return err
}
filename := mime.QEncoding.Encode("utf-8", att.Name+".pgp")
var hdr message.Header
hdr.SetContentType("application/octet-stream", map[string]string{"name": filename})
hdr.SetContentDisposition(string(att.Disposition), map[string]string{"filename": filename})
part, err := w.CreatePart(hdr)
if err != nil {
return err
}
if _, err := part.Write([]byte(arm)); err != nil {
return err
}
return part.Close()
}