128-bit Encryption

[rajveerg22]

Thaks in advance for reading my thread....
Just now we have decided that have to implement 128-bit encryption code...
and we prepared some code in java...
and thats not giving the exact ouput of encrypted and decrypted text ....
Please Provide any 128-bit Encryption code snippets so that i can move forward the below is the code which i prepared

//package encryption; 
import java.math.BigInteger;
import java.security.SecureRandom; 
import java.lang.*;
import org.bouncycastle.crypto.AsymmetricBlockCipher;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.encodings.PKCS1Encoding;
import org.bouncycastle.crypto.engines.RSAEngine;
import org.bouncycastle.crypto.generators.RSAKeyPairGenerator;
import org.bouncycastle.crypto.params.RSAKeyGenerationParameters;
import org.bouncycastle.crypto.params.RSAKeyParameters;
import org.bouncycastle.crypto.params.RSAPrivateCrtKeyParameters;

public class Encryption {

    private RSAPrivateCrtKeyParameters _RSAPrivateKey;
    private RSAKeyParameters _RSAPublicKey;

    public static void main(String[] args) {
        Encryption theEncryption = new Encryption();
        String theStringBeforeEncryption = "r";
        String theStringAfterEncryption = null;
        byte[] theEncryptedString;

        try {
            System.out.println(theStringBeforeEncryption);
            theEncryption.generateRSAKeyPair();         
            theEncryptedString = theEncryption.RSAEncrypt(theStringBeforeEncryption.getBytes());
            String str=(new Base64Converter()).encode(theEncryptedString);
            System.out.println(str);

            System.out.println(theEncryptedString);
            theStringAfterEncryption = new String(theEncryption.RSADecrypt(theEncryptedString));
            System.out.println(theStringAfterEncryption);           
        } 
        catch (Exception e) 
            {
            // TODO Handle exception!
            e.printStackTrace();
            }
    }

    private void generateRSAKeyPair ( ) throws Exception {
        SecureRandom theSecureRandom = new SecureRandom();
        BigInteger thePublicExponent = new BigInteger("10001", 16);
        RSAKeyGenerationParameters theRSAKeyGenParam =
            new RSAKeyGenerationParameters(thePublicExponent, theSecureRandom, 1024, 80);
        RSAKeyPairGenerator theRSAKeyPairGen = new RSAKeyPairGenerator();
        theRSAKeyPairGen.init(theRSAKeyGenParam);
        AsymmetricCipherKeyPair theKeyPair = theRSAKeyPairGen.generateKeyPair();

        _RSAPrivateKey = (RSAPrivateCrtKeyParameters) theKeyPair.getPrivate();
        _RSAPublicKey = (RSAKeyParameters) theKeyPair.getPublic();
    }

    private byte [] RSAEncrypt (byte [] toEncrypt) throws Exception 
        {

        if (_RSAPublicKey == null) 
            {
            throw new Exception("Please generate RSA keys first in order to work");
            }
        AsymmetricBlockCipher theEngine = new RSAEngine();
        theEngine = new PKCS1Encoding(theEngine);
        theEngine.init(true, _RSAPublicKey);
        return theEngine.processBlock(toEncrypt, 0, toEncrypt.length);
    }

    private byte [] RSADecrypt (byte [] toDecrypt) throws Exception {

        if (_RSAPrivateKey == null) 
            {
            throw new Exception("Please generate RSA keys first in order to work");
            }       
        AsymmetricBlockCipher theEngine = new RSAEngine();
        theEngine = new PKCS1Encoding(theEngine);
        theEngine.init(false, _RSAPrivateKey);
        return theEngine.processBlock(toDecrypt, 0, toDecrypt.length);
    }   

}

 class  Base64Converter
      //////////////////////////////////////////////////////////////////////
      //////////////////////////////////////////////////////////////////////
      {

     public static final char [ ]  alphabet = {
        'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',   //  0 to  7
        'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',   //  8 to 15
        'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',   // 16 to 23
        'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',   // 24 to 31
        'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',   // 32 to 39
        'o', 'p', 'q', 'r', 's', 't', 'u', 'v',   // 40 to 47
        'w', 'x', 'y', 'z', '0', '1', '2', '3',   // 48 to 55
        '4', '5', '6', '7', '8', '9', '+', '/' }; // 56 to 63

     //////////////////////////////////////////////////////////////////////
      //////////////////////////////////////////////////////////////////////

     public static String  encode ( String  s )
      //////////////////////////////////////////////////////////////////////
      {
        return encode ( s.getBytes ( ) );
      }

     public static String  encode ( byte [ ]  octetString )
      //////////////////////////////////////////////////////////////////////
      {
        int  bits24;
        int  bits6;

       char [ ]  out
          = new char [ ( ( octetString.length - 1 ) / 3 + 1 ) * 4 ];

       int outIndex = 0;
        int i        = 0;

       while ( ( i + 3 ) <= octetString.length )
        {
          // store the octets
          bits24  = ( octetString [ i++ ] & 0xFF ) << 16; 
          bits24 |= ( octetString [ i++ ] & 0xFF ) <<  8; 
          bits24 |= ( octetString [ i++ ] & 0xFF ) <<  0;

         bits6 = ( bits24 & 0x00FC0000 ) >> 18; 
          out [ outIndex++ ] = alphabet [ bits6 ];
          bits6 = ( bits24 & 0x0003F000 ) >> 12; 
          out [ outIndex++ ] = alphabet [ bits6 ];
          bits6 = ( bits24 & 0x00000FC0 ) >> 6; 
          out [ outIndex++ ] = alphabet [ bits6 ];
          bits6 = ( bits24 & 0x0000003F );
          out [ outIndex++ ] = alphabet [ bits6 ]; 
        }

       if ( octetString.length - i == 2 )
        {
          // store the octets 
          bits24  = ( octetString [ i     ] & 0xFF ) << 16; 
          bits24 |= ( octetString [ i + 1 ] & 0xFF ) <<  8;

         bits6 = ( bits24 & 0x00FC0000 ) >> 18;
          out [ outIndex++ ] = alphabet [ bits6 ]; 
          bits6 = ( bits24 & 0x0003F000 ) >> 12; 
          out [ outIndex++ ] = alphabet [ bits6 ]; 
          bits6 = ( bits24 & 0x00000FC0 ) >> 6; 
          out [ outIndex++ ] = alphabet [ bits6 ];

         // padding
          out [ outIndex++ ] = '='; 
        }
        else if ( octetString.length - i == 1 )
        {
          // store the octets 
          bits24 = ( octetString [ i ] & 0xFF ) << 16;

         bits6 = ( bits24 & 0x00FC0000 ) >> 18;
          out [ outIndex++ ] = alphabet [ bits6 ];
          bits6 = ( bits24 & 0x0003F000 ) >> 12; 
          out [ outIndex++ ] = alphabet [ bits6 ];

         // padding
          out [ outIndex++ ] = '='; 
          out [ outIndex++ ] = '='; 
        }

       return new String ( out );
      }

     //////////////////////////////////////////////////////////////////////
      //////////////////////////////////////////////////////////////////////
      }