proton-bridge/pkg/message/body.go

76 lines
2.2 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 message
import (
"encoding/base64"
"fmt"
"io"
"mime/quotedprintable"
"github.com/ProtonMail/gopenpgp/v2/crypto"
"github.com/ProtonMail/proton-bridge/pkg/pmapi"
"github.com/emersion/go-textwrapper"
openpgperrors "golang.org/x/crypto/openpgp/errors"
)
func WriteBody(w io.Writer, kr *crypto.KeyRing, m *pmapi.Message) error {
// Decrypt body.
if err := m.Decrypt(kr); err != nil && err != openpgperrors.ErrSignatureExpired {
return err
}
if m.MIMEType != pmapi.ContentTypeMultipartMixed {
// Encode it.
qp := quotedprintable.NewWriter(w)
if _, err := io.WriteString(qp, m.Body); err != nil {
return err
}
return qp.Close()
}
_, err := io.WriteString(w, m.Body)
return err
}
func WriteAttachmentBody(w io.Writer, kr *crypto.KeyRing, m *pmapi.Message, att *pmapi.Attachment, r io.Reader) (err error) {
// Decrypt it
var dr io.Reader
dr, err = att.Decrypt(r, kr)
if err == openpgperrors.ErrKeyIncorrect {
// Do not fail if attachment is encrypted with a different key.
dr = r
err = nil
att.Name += ".gpg"
att.MIMEType = "application/pgp-encrypted" //nolint
} else if err != nil && err != openpgperrors.ErrSignatureExpired {
err = fmt.Errorf("cannot decrypt attachment: %v", err)
return
}
// Encode it.
ww := textwrapper.NewRFC822(w)
bw := base64.NewEncoder(base64.StdEncoding, ww)
var n int64
if n, err = io.Copy(bw, dr); err != nil {
err = fmt.Errorf("cannot write attachment: %v (wrote %v bytes)", err, n)
}
_ = bw.Close()
return
}