103 lines
2.1 KiB
Go
103 lines
2.1 KiB
Go
// Implements MIME security with OpenPGP, as defined in RFC 3156.
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package pgpmime
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import (
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"io"
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"mime/multipart"
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"net/textproto"
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"golang.org/x/crypto/openpgp"
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)
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// A PGP/MIME encrypter.
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type Encrypter struct {
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multipart *multipart.Writer
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armored io.WriteCloser
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encrypted io.WriteCloser
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to []*openpgp.Entity
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signed *openpgp.Entity
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opened bool
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}
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// Write control information and create encrypted part.
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func (ew *Encrypter) open() (err error) {
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// Create control information
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h := make(textproto.MIMEHeader)
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h.Add("Content-Type", "application/pgp-encrypted")
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hw, err := ew.multipart.CreatePart(h)
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if err != nil {
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return
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}
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if _, err = io.WriteString(hw, "Version: 1\r\n"); err != nil {
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return
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}
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// Create body part
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h = make(textproto.MIMEHeader)
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h.Add("Content-Type", "application/octet-stream")
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h.Add("Content-Disposition", "inline")
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bw, err := ew.multipart.CreatePart(h)
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if err != nil {
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return
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}
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// Create encrypted part
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if ew.armored, err = EncodeArmoredMessage(bw); err != nil {
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return
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}
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if ew.encrypted, err = openpgp.Encrypt(ew.armored, ew.to, ew.signed, nil, nil); err != nil {
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return
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}
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return
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}
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// Write encrypted data.
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func (ew *Encrypter) Write(b []byte) (n int, err error) {
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// Make sure parts required at the begining of the message have been written
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if !ew.opened {
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if err = ew.open(); err != nil {
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return
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}
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ew.opened = true
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}
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return ew.encrypted.Write(b)
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}
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// Finish the PGP/MIME message.
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func (ew *Encrypter) Close() (err error) {
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if !ew.opened {
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if err = ew.open(); err != nil {
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return
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}
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ew.opened = true
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}
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if err = ew.encrypted.Close(); err != nil {
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return
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}
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if err = ew.armored.Close(); err != nil {
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return
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}
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err = ew.multipart.Close()
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return
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}
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// Get the Content-Type of this PGP/MIME message.
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func (ew *Encrypter) ContentType() string {
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return "multipart/encrypted; boundary=" + ew.multipart.Boundary() + "; protocol=\"application/pgp-encrypted\""
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}
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// Create a new PGP/MIME encrypter.
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func NewEncrypter(w io.Writer, to []*openpgp.Entity, signed *openpgp.Entity) *Encrypter {
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return &Encrypter{
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multipart: multipart.NewWriter(w),
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to: to,
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signed: signed,
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}
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}
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