New functions for flutter openpgp compatibility

asymcrypt.go

@@ -192,3 +192,110 @@ func createPublicKeyRing(publicKey string) (*crypto.KeyRing, error) {
 
 	return publicKeyRing, nil
 }
+
+func AsymEncryptAndSign2(PublicEncryptionKey string, PrivateSignatureKey string, data []byte) ([]byte, []byte, error) {
+	pub, err := base64.StdEncoding.DecodeString(PublicEncryptionKey)
+	if err != nil {
+		log.Error().Msg("Message encryption and sign b64 failed")
+	}
+	priv, err := base64.StdEncoding.DecodeString(PrivateSignatureKey)
+	if err != nil {
+		log.Error().Msg("Message encryption and sign b64 failed")
+	}
+	ciphertext, signature, err := encryptAndSignMessage(string(pub), string(priv), crypto.NewPlainMessage(data))
+	if err != nil {
+		log.Error().Msg("Message encryption failed")
+		return nil, nil, err
+	}
+	return ciphertext.GetBinary(), signature, err
+}
+
+func AsymDecryptAndCheck2(MyPrivateEncryptionKey string, MyContactPublicKey string, data []byte, Signature []byte) (DecryptedMessage []byte, err error) {
+	priv, err := base64.StdEncoding.DecodeString(MyPrivateEncryptionKey)
+	if err != nil {
+		log.Error().Msg("Message decryption and sign b64 failed")
+	}
+	pub, err := base64.StdEncoding.DecodeString(MyContactPublicKey)
+	if err != nil {
+		log.Error().Msg("Message decryption and sign b64 failed")
+	}
+	DecryptedMessage, err = decryptAndCheckMessage(string(pub), string(priv), crypto.NewPGPMessage(data), crypto.NewPGPSignature(Signature))
+	if err != nil {
+		log.Error().Msg("Message decryption and sign failed")
+	}
+	return DecryptedMessage, err
+}
+
+func encryptAndSignMessage(pub string, priv string, message *crypto.PlainMessage) (*crypto.PGPMessage, []byte, error) {
+	var privateKeyObj, unlockedKeyObj *crypto.Key
+	var privateKeyRing *crypto.KeyRing
+	publicKeyRing, err := createPublicKeyRing(pub)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "gopenpgp: unable to encrypt message")
+	}
+
+	if privateKeyObj, err = crypto.NewKeyFromArmored(priv); err != nil {
+		return nil, nil, errors.Wrap(err, "gopenpgp: unable to parse private key")
+	}
+
+	if unlockedKeyObj, err = privateKeyObj.Unlock(nil); err != nil {
+		return nil, nil, errors.Wrap(err, "gopenpgp: unable to unlock key")
+	}
+	defer unlockedKeyObj.ClearPrivateParams()
+
+	if privateKeyRing, err = crypto.NewKeyRing(unlockedKeyObj); err != nil {
+		return nil, nil, errors.Wrap(err, "gopenpgp: unable to create private keyring")
+	}
+
+	ciphertext, err := publicKeyRing.Encrypt(message, nil)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "gopenpgp: unable to encrypt message")
+	}
+
+	signature, err := privateKeyRing.SignDetached(message)
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "gopenpgp: unable to encrypt message")
+	}
+	return ciphertext, signature.GetBinary(), nil
+}
+
+func decryptAndCheckMessage(pub string, priv string, message *crypto.PGPMessage, signature *crypto.PGPSignature) ([]byte, error) {
+	var privateKeyObj, unlockedKeyObj *crypto.Key
+	var privateKeyRing *crypto.KeyRing
+	publicKeyRing, err := createPublicKeyRing(pub)
+	if err != nil {
+		return nil, err
+	}
+
+	if err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to encrypt message")
+	}
+
+	if privateKeyObj, err = crypto.NewKeyFromArmored(priv); err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to parse private key")
+	}
+
+	if unlockedKeyObj, err = privateKeyObj.Unlock(nil); err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to unlock key")
+	}
+	defer unlockedKeyObj.ClearPrivateParams()
+
+	if privateKeyRing, err = crypto.NewKeyRing(unlockedKeyObj); err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to create private keyring")
+	}
+
+	plainmessage, err := privateKeyRing.Decrypt(message, nil, 0)
+	if err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to decrypt message")
+	}
+
+	err = publicKeyRing.VerifyDetached(plainmessage, signature, crypto.GetUnixTime())
+	if err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to check message signature")
+	}
+	return plainmessage.GetBinary(), nil
+}