perform ECDSA signature without calling update

src/xyz/wendland/javacard/pki/isoapplet/IsoApplet.java

@@ -1272,14 +1272,13 @@ private void computeDigitalSignature(APDU apdu) throws ISOException {
  short lc;
  short sigLen = 0;
 
+ // Receive.
+ // Bytes received must be Lc.
+ lc = readIncomingDataIntoRam(apdu);
 
  switch(currentAlgorithmRef[0]) {
  case ALG_RSA_PAD_PKCS1:
  case ALG_RSA_PAD_PSS:
- // Receive.
- // Bytes received must be Lc.
- lc = readIncomingDataIntoRam(apdu);
-
  // RSA signature operation.
  RSAPrivateCrtKey rsaKey = (RSAPrivateCrtKey) keys[currentPrivateKeyRef[0]];
 
@@ -1328,28 +1327,13 @@ private void computeDigitalSignature(APDU apdu) throws ISOException {
  apdu.sendBytesLong(ram_buf, lc, sigLen);
  break;
 
- case ALG_ECDSA_SHA1:
+ case ALG_ECDSA:
  // Get the key - it must be a EC private key,
  // checks have been done in MANAGE SECURITY ENVIRONMENT.
  ECPrivateKey ecKey = (ECPrivateKey) keys[currentPrivateKeyRef[0]];
-
  ecdsaSignature.init(ecKey, Signature.MODE_SIGN);
-
- short recvLen = apdu.setIncomingAndReceive();
- short offset_cdata = apdu.getOffsetCdata();
- byte[] buf = apdu.getBuffer();
-
- // Receive data. For extended APDUs, the data is received piecewise
- // and aggregated in the hash. When using short APDUs, command
- // chaining is performed.
- while (recvLen > 0) {
- ecdsaSignature.update(buf, offset_cdata, recvLen);
- recvLen = apdu.receiveBytes(offset_cdata);
- }
-
- sigLen = ecdsaSignature.sign(buf, (short)0, (short)0, buf, (short) 0);
+ sigLen = ecdsaSignature.sign(ram_buf, (short)0, lc, apdu.getBuffer(), (short)0);
  apdu.setOutgoingAndSend((short) 0, sigLen);
-
  break;
 
  default: