passforios-gopenpgp/helper/mobile.go
2020-04-07 15:19:48 +02:00

80 lines
2.4 KiB
Go

package helper
import (
"encoding/json"
"github.com/ProtonMail/gopenpgp/v2/crypto"
)
type ExplicitVerifyMessage struct {
Message *crypto.PlainMessage
SignatureVerificationError *crypto.SignatureVerificationError
}
// DecryptVerifyMessageArmored decrypts an armored PGP message given a private key and its passphrase
// and verifies the embedded signature.
// Returns the plain data or an error on signature verification failure.
func DecryptExplicitVerify(
pgpMessage *crypto.PGPMessage,
privateKeyRing, publicKeyRing *crypto.KeyRing,
verifyTime int64,
) (*ExplicitVerifyMessage, error) {
var explicitVerify *ExplicitVerifyMessage
message, err := privateKeyRing.Decrypt(pgpMessage, publicKeyRing, verifyTime)
if err != nil {
castedErr, isType := err.(crypto.SignatureVerificationError)
if !isType {
return nil, err
}
explicitVerify = &ExplicitVerifyMessage{
Message: message,
SignatureVerificationError: &castedErr,
}
} else {
explicitVerify = &ExplicitVerifyMessage{
Message: message,
SignatureVerificationError: nil,
}
}
return explicitVerify, nil
}
// DecryptAttachment takes a keypacket and datpacket
// and returns a decrypted PlainMessage
// Specifically designed for attachments rather than text messages.
func DecryptAttachment(keyPacket []byte, dataPacket []byte, keyRing *crypto.KeyRing) (*crypto.PlainMessage, error) {
splitMessage := crypto.NewPGPSplitMessage(keyPacket, dataPacket)
decrypted, err := keyRing.DecryptAttachment(splitMessage)
if err != nil {
return nil, err
}
return decrypted, nil
}
// EncryptAttachment encrypts a file given a plainData and a fileName.
// Returns a PGPSplitMessage containing a session key packet and symmetrically encrypted data.
// Specifically designed for attachments rather than text messages.
func EncryptAttachment(plainData []byte, fileName string, keyRing *crypto.KeyRing) (*crypto.PGPSplitMessage, error) {
plainMessage := crypto.NewPlainMessage(plainData)
decrypted, err := keyRing.EncryptAttachment(plainMessage, fileName)
if err != nil {
return nil, err
}
return decrypted, nil
}
// GetJsonSHA256Fingerprints returns the SHA256 fingeprints of key and subkeys, encoded in JSON, since gomobile can not
// handle arrays
func GetJsonSHA256Fingerprints(publicKey string) ([]byte, error) {
key, err := crypto.NewKeyFromArmored(publicKey)
if err != nil {
return nil, err
}
return json.Marshal(key.GetSHA256Fingerprints())
}