Problem with byte[].length

Question

dear sir
I am working with javacard 2.2.2, windows, jdk 1.5 and JCWDE
I would like to know the byte length of an array ("aCrypter" in this fallowing code)
1     public byte[] cryter(byte[] Crypter){
2
3          ecipher.init(key, Cipher.MODE_ENCRYPT);
4          ecipher.doFinal(Crypter, (short)0, (short)aCrypter.length, donneeCrypter , (short)0);
5          
6          return donneeCrypter;
7     }
JCVM return an error on line 4 (it works with "(short)1"
there is a solution to know the array length?
regards
Alexis
Edited by: Alexis "le francais" on 21 mars 2011 07:33

Answer 1

thanks for your help.
In fact I would like to crypt and after decrypt with this fallowing code:
       private byte[] Crypto = {(byte)0xA0, (byte)0x00,
             (byte)0x00, (byte)0x00, (byte)0x62, (byte)0x03, (byte)0x01, (byte)0x0C,
             (byte)0x0f, (byte)0x01, (byte)0x01};
public void process(APDU apdu) throws ISOException {
          // TODO Auto-generated method stub
          byte[] buffer = apdu.getBuffer();
          if (this.selectingApplet()) return;
          if (buffer[ISO7816.OFFSET_CLA] != CLA_MONAPPLET) {
               ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);
          switch (buffer[ISO7816.OFFSET_INS]) {
               case INS_INTERROGER_COMPTEUR:
                    tab = new byte[1000];
                    tab[0]= compteur;               
                    tableau = cryter(tab);
                    tableau2= decrypter(tableau);                    
                    apdu.setOutgoing();
                    apdu.setOutgoingLength((short) 7);
                    apdu.sendBytesLong(tableau2,(short) 0, tableau2.lenght);
                    break;          
     public void initialisation(){
        key = (DESKey)KeyBuilder.buildKey(KeyBuilder.TYPE_DES_TRANSIENT_DESELECT,KeyBuilder.LENGTH_DES, false);
        key.setKey(Crypto, (short)0);
        ecipher = Cipher.getInstance(Cipher.ALG_DES_CBC_ISO9797_M2,false);
     public byte[] decrypter(byte[] aDecrypter){
          ecipher.init(key, Cipher.MODE_DECRYPT);
          donneeDecrypte = new byte[10000];
          ecipher.doFinal(aDecrypter, (short)0, (short)aDecrypter.length, donneeDecrypte, (short)0);
          return donneeDecrypte;
     public byte[] cryter(byte[] Crypter){
          ecipher.init(key, Cipher.MODE_ENCRYPT);
          donneeCrypter = new byte[10000];
          ecipher.doFinal(Crypter, (short)0, (short)Crypter.length, donneeCrypter, (short)0);
          return donneeCrypter;
     }Now "crypter" method is executed, but when the debugger is at this fallowing line there is a problem :
tableau2= decrypter(tableau);maybe the size of the array?
>
return ecipher.doFinal(aCrypter);
>
I work with Javacard 2.2.2, this method does not exist in the API only :
abstract short doFinal270(byte[] inBuff, short inOffset, short inLength,byte[] outBuff, short outOffset)Edited by: le francais on 22 mars 2011 03:07