can plz solve this

hello ghstark .....

iam adding code here ...this is to encrypt and decrypt the voice mails

Iam reading the voice bytes and encrypting them and sending them

At the other side iam decrypting and sending to speaker...

Iam pasting the three classes here ..key generation(common key -AES),and Encryption and Decryption....

Its working fine when i did in single system...but not in cllient-server voice sys....i think there was a problem with no. of bytes i send and receive...will it be a problem?

import java.security.*;

import javax.crypto.*;

import javax.crypto.spec.*;

public class Aesx{

public Key getKey() throws Exception

{

/** AES key size of 128 bits **/

byte[] keyBytes = new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,

0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};

Key key = new SecretKeySpec(keyBytes, "AES");

return key;

}

// encryption pass

public byte[] encrypt(byte[] plaintext,Key key) throws Exception

{

Cipher cipher = Cipher.getInstance("AES");

try{

cipher.init(Cipher.ENCRYPT_MODE,key);

}

catch(Exception e)

{

e.printStackTrace();

}

byte[] cipherText = new byte[cipher.getOutputSize(plaintext.length)];

int ctLength = cipher.update(plaintext, 0, plaintext.length, cipherText, 0);

ctLength += cipher.doFinal(cipherText, ctLength);

return cipherText;

}

// decryption pass

public byte[] decrypt(byte[] cipherText,Key key) throws Exception

{

Cipher cipher = Cipher.getInstance("AES");

cipher.init(Cipher.DECRYPT_MODE, key);

byte[] plainText = new byte[cipher.getOutputSize(cipherText.length)];

int ptLength = cipher.update(cipherText, 0, cipherText.length, plainText, 0);

ptLength += cipher.doFinal(plainText, ptLength);

return plainText;

}

}

And iam getting the EXCEPTION as like this....

javax.crypto.BadPaddingException: Given final block not properly padded

at com.sun.crypto.provider.SunJCE_h.b(DashoA6275)

at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA6275)

at javax.crypto.Cipher.doFinal(DashoA12275)

at other.Aesx.decrypt(Aesx.java:59)

at audio.Speaker.run(Speaker.java:202)

Speaker.run(): javax.crypto.BadPaddingException: Given final block not properly

Eagerly waiting for ur reply.....b bye ..thanks in advance

boddu@secuirtya at 2007-7-15 5:56:19 >

Your decrypt method needs exactly the same bytes as that were returned by the encrypt method. In other words, you cannot encrypt 500 bytes using one call of encrypt (on the sending side) and then decrypt (on the receiving side) 150 bytes with one decrypt call and then 350 bytes with a second decrypt call. To be able to encrypt and decrypt in pieces you must not call doFinal().

What you want is byte-oriented streaming. Therefore, I think the most natural solution is to use CipherInputStream and CipherOutputStream with the RC4 algorithm, i.e. Cipher rc4 = Cipher.getInstance("RC4/ECB/NoPadding");

You must also generate a random salt and and hash this into the key. This salt must be transmitted in the clear at the beginning of the cipher. You should also MAC the data.

Basically, you need to provide all the functionality that is already provide by SSL/TLS. Of course, I would recommend that you simply use SSL/TLS as available in the Sun JSSE

ghstarka at 2007-7-15 5:56:19 >