// Verify implements SigningMechanism.Verify
func (m gpgSigningMechanism) Verify(unverifiedSignature []byte) (contents []byte, keyIdentity string, err error) {
signedBuffer := bytes.Buffer{}
signedData, err := gpgme.NewDataWriter(&signedBuffer)
if err != nil {
return nil, "", err
}
unverifiedSignatureData, err := gpgme.NewDataBytes(unverifiedSignature)
if err != nil {
return nil, "", err
}
_, sigs, err := m.ctx.Verify(unverifiedSignatureData, nil, signedData)
if err != nil {
return nil, "", err
}
if len(sigs) != 1 {
return nil, "", InvalidSignatureError{msg: fmt.Sprintf("Unexpected GPG signature count %d", len(sigs))}
}
sig := sigs[0]
// This is sig.Summary == gpgme.SigSumValid except for key trust, which we handle ourselves
if sig.Status != nil || sig.Validity == gpgme.ValidityNever || sig.ValidityReason != nil || sig.WrongKeyUsage {
// FIXME: Better error reporting eventually
return nil, "", InvalidSignatureError{msg: fmt.Sprintf("Invalid GPG signature: %#v", sig)}
}
return signedBuffer.Bytes(), sig.Fingerprint, nil
}
// ImportKeysFromBytes implements SigningMechanism.ImportKeysFromBytes
func (m gpgSigningMechanism) ImportKeysFromBytes(blob []byte) ([]string, error) {
inputData, err := gpgme.NewDataBytes(blob)
if err != nil {
return nil, err
}
res, err := m.ctx.Import(inputData)
if err != nil {
return nil, err
}
keyIdentities := []string{}
for _, i := range res.Imports {
if i.Result == nil {
keyIdentities = append(keyIdentities, i.Fingerprint)
}
}
return keyIdentities, nil
}
// Sign implements SigningMechanism.Sign
func (m gpgSigningMechanism) Sign(input []byte, keyIdentity string) ([]byte, error) {
key, err := m.ctx.GetKey(keyIdentity, true)
if err != nil {
return nil, err
}
inputData, err := gpgme.NewDataBytes(input)
if err != nil {
return nil, err
}
var sigBuffer bytes.Buffer
sigData, err := gpgme.NewDataWriter(&sigBuffer)
if err != nil {
return nil, err
}
if err = m.ctx.Sign([]*gpgme.Key{key}, inputData, sigData, gpgme.SigModeNormal); err != nil {
return nil, err
}
return sigBuffer.Bytes(), nil
}