add support for decrypt RSA OAEP

README.md

@@ -14,6 +14,7 @@ Currently the following commands are implemented:
  * PutAsymmetricKey
  * GetPubKey
  * DeriveEcdh
+ * DecryptOaep
  * Echo
  * ChangeAuthenticationKey
  * PutAuthenticationKey

commands/constructors.go

@@ -264,6 +264,24 @@ func CreateDeriveEcdhCommand(objID uint16, pubkey []byte) (*CommandMessage, erro
 	return command, nil
 }
 
+func CreateDecryptOaepCommand(objID uint16, algorithm Algorithm, ciphertextFile []byte) (*CommandMessage, error) {
+	if algorithm < AlgorithmRSAOAEPSHA1 || algorithm > AlgorithmRSAOAEPSHA512 {
+        return nil, errors.New("invalid algorithm")
+    }
+
+	command := &CommandMessage{
+		CommandType: CommandTypeDecryptOaep,
+	}
+
+	payload := bytes.NewBuffer([]byte{})
+	binary.Write(payload, binary.BigEndian, objID)
+	binary.Write(payload, binary.BigEndian, algorithm)
+	payload.Write(ciphertextFile)
+	command.Data = payload.Bytes()
+
+	return command, nil
+}
+
 func CreateChangeAuthenticationKeyCommand(objID uint16, newPassword string) (*CommandMessage, error) {
 	command := &CommandMessage{
 		CommandType: CommandTypeChangeAuthenticationKey,

commands/response.go

@@ -94,6 +94,10 @@ type (
 		XCoordinate []byte
 	}
 
+    DecryptOaepResponse struct {
+		Plaintext []byte
+	}
+
 	ChangeAuthenticationKeyResponse struct {
 		ObjectID uint16
 	}
@@ -183,6 +187,8 @@ func ParseResponse(data []byte) (Response, error) {
 		return parseEchoResponse(payload)
 	case CommandTypeDeriveEcdh:
 		return parseDeriveEcdhResponse(payload)
+    case CommandTypeDecryptOaep:
+		return parseDecryptOaepResponse(payload)
 	case CommandTypeChangeAuthenticationKey:
 		return parseChangeAuthenticationKeyResponse(payload)
 	case CommandTypeGetPseudoRandom:
@@ -364,6 +370,12 @@ func parseDeriveEcdhResponse(payload []byte) (Response, error) {
 	}, nil
 }
 
+func parseDecryptOaepResponse(payload []byte) (Response, error) {
+	return &DecryptOaepResponse{
+		Plaintext: payload,
+	}, nil
+}
+
 func parseChangeAuthenticationKeyResponse(payload []byte) (Response, error) {
 	if len(payload) != 2 {
 		return nil, errors.New("invalid response payload length")