/**
* Generate an assymetric RSA key pair according to ISO7816-8, Section 5.1. We only support RSA
* 1024 bit at the moment, and return data in simple TLV data objects, tags 81 and 82.
*
* <p>Successful MSE command has to be performed prior to this one.
*/
private void processGenerateAssymetricKeyPair(APDU apdu) {
// This is only valid in state initial (at the moment)
if (state != STATE_INITIAL) {
ISOException.throwIt(SW_INS_NOT_SUPPORTED);
}
byte[] buf = apdu.getBuffer();
byte p1 = buf[OFFSET_P1];
byte p2 = buf[OFFSET_P2];
if (p1 != (byte) 0x80 || p2 != (byte) 0x00) {
ISOException.throwIt(SW_INCORRECT_P1P2);
}
if (currentPrivateKey[0] == null) {
ISOException.throwIt(SW_CONDITIONS_NOT_SATISFIED);
}
KeyPair pair = new KeyPair(tempKeyPublic, (RSAPrivateCrtKey) currentPrivateKey[0]);
pair.genKeyPair();
// Sanity check, the KeyPair class should regenerate the keys "in place".
if (pair.getPrivate() != currentPrivateKey[0] || pair.getPublic() != tempKeyPublic) {
ISOException.throwIt(SW_DATA_INVALID);
}
apdu.setOutgoing();
short len = (short) 0;
short offset = 0;
buf[offset++] = (byte) 0x81;
len = tempKeyPublic.getModulus(buf, (short) (offset + 2));
buf[offset++] = (byte) 0x81;
buf[offset++] = (byte) len;
offset += len;
buf[offset++] = (byte) 0x82;
len = tempKeyPublic.getExponent(buf, (short) (offset + 1));
buf[offset++] = (byte) len;
offset += len;
apdu.setOutgoingLength(offset);
apdu.sendBytes((short) 0, offset);
}
public void process(APDU apdu) {
// Good practice: Return 9000 on SELECT
if (selectingApplet()) {
return;
}
byte[] buff = apdu.getBuffer();
// Get the incoming APDU
// Util.arrayCopy(apdu.getBuffer(),(short) 0, buff,(short) 0,(short) apdu.getBuffer().length);//
// apdu.getBuffer();
// Check the CLA
/*
if(buff[ISO7816.OFFSET_CLA]!=CLA){
ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);
}
*/
// Switch on the instruction code INS
switch (buff[ISO7816.OFFSET_INS]) {
// Create a test signature using test
case SEND_TEST_SIGNATURE:
// Sign the test byte and get the signature size
size = sig.sign(test, (short) 0, (short) test.length, output, (short) 0);
break;
// return modulus of public key
case SEND_PUB_MOD:
// Retrieve the modulus, store it in the output byte array and set the output length
size = k.getModulus(output, (short) 0);
break;
// return exponent of public key
case SEND_PUB_EXP:
// Retrieve the public exponent, store it in the output byte array and set the output
// length
size = k.getExponent(output, (short) 0);
break;
// return exponent of private key given correct pin authentication
case SEND_PRV_EXP:
// Check that the user is authenticated (correct command 0x80 0x03 0x01 0x00 0x04 0x00 0x00
// 0x00 0x00 0x00)
if (buff[ISO7816.OFFSET_P1] == ((byte) 0x01)) {
if (buff[ISO7816.OFFSET_LC] != (byte) 0x00) {
if (pin.check(buff, (short) (ISO7816.OFFSET_LC + 1), buff[ISO7816.OFFSET_LC])) {
size = k2.getExponent(output, (short) 0);
pin.reset();
} else {
// wrong pin (system should have taken care of decrementing the counter and checking
// boundary conditions)
ISOException.throwIt(ISO7816.SW_WRONG_DATA);
}
} else {
ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED); // no pin was sent
}
} else {
ISOException.throwIt(ISO7816.SW_INCORRECT_P1P2); // wrong command code
}
// Retrieve the private exponent, store it in the output byte array and set the output
// length
size = k2.getExponent(output, (short) 0);
break;
// return size of signature and modulus for testing purposes (they should be the same)
case (byte) SEND_KEY_LENGTH:
shortToByteArray(keysize);
size = (short) 2;
Util.arrayCopy(buff, (short) 0, output, (short) 0, size);
break;
// Sign arbitrary text sent to card
case (byte) SIGN_INPUT_DATA:
size = (short) buff[ISO7816.OFFSET_LC];
size = sig.sign(buff, (short) (ISO7816.OFFSET_LC + 1), size, output, (short) 0);
break;
// return the modulus of public keywith a random value sent from the host
case (byte) SEND_AUTHENTICATED_PUB_EXP:
// Find the size of the random value
size = (short) buff[ISO7816.OFFSET_LC];
// If the current key is 2048 bit =256 bytes we need a big array to store all data to sign
// TODO limit the size of the input value and do some checks on it
bigArray =
JCSystem.makeTransientByteArray((short) (size + keysize), JCSystem.CLEAR_ON_RESET);
// Update the signature object with that value
Util.arrayCopy(buff, (short) (ISO7816.OFFSET_LC + 1), bigArray, (short) 0, size);
k.getModulus(bigArray, (short) (size));
// Util.arrayCopy(buff, (short) 0, bigArray, (short) (ISO7816.OFFSET_LC+size+1), len);
size = sig.sign(bigArray, (short) 0, (short) bigArray.length, output, (short) 0);
break;
case (byte) 0x07:
size = (short) 2;
output[0] = (byte) 0x09;
output[1] = (byte) 0x08;
break;
case (byte) 0x08:
short length = 256;
// short length = (short) buff.length;
size = (short) length;
// output[0]=(byte) 0x08;
// output[1]=(byte) 0x08;
for (short i = 0; i < length; i++) {
output[i] = (byte) buff[i];
}
break;
default:
// good practice: If you don't know the INStruction, say so:
ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
}
send(apdu);
}