/com.documentum.devprog/src/com/documentum/devprog/eclipse/common/BlowfishJC.java

/*

 * Created on Jan 29, 2007

 *

 * EMC Developer Network 

 */

package com.documentum.devprog.eclipse.common;



import javax.crypto.Cipher;

import javax.crypto.spec.SecretKeySpec;



/**

 * 

 * Blowfish encrypt/decrypt algorithm wrappers around the Java Crypto API 

 * implementation

 * 

 * 

 * @author Aashish Patil(patil_aashish@emc.com)

 */

public class BlowfishJC

{

    

    private BlowfishJC()

    {

        //blank ctor 

        //no need for a ctor 

    }

    

    



    /**

     * Encrypts the data using the provided key. 

     * 

     * <br/>

     * Note that when converting from bytes to String and vice versa the default platform 

     * encoding is used.  

     * 

     * <br/>

     * Algo Specs:

     * Blowfish/ECB/PKCS5Padding

     * 

     * @param key shared key

     * @param data data to be encrypted.

     * @return encrypted data as a string.

     * @throws Exception

     */

    public static String encryptString(String key,String data) throws Exception

    {

        byte[] dataBytes = data.getBytes();

        return new String(encryptData(key,dataBytes));

    }

    

    /**

     * Decrypts the encrypted data using the provided key.

     * 

     * 

     * <br/>

     * Note that when converting from bytes to String and vice versa the default platform 

     * encoding is used.

     * 

     * <br/>

     * Algo Specs:

     * Blowfish/ECB/PKCS5Padding

     * 

     * @param key shared key

     * @param encrString Encrypted data

     * @return Decrypted data

     * @throws Exception 

     * 

     * 

     */

    public static String decryptString(String key,String encrString) throws Exception

    {

        byte[] encrData = encrString.getBytes();

        return new String(decryptData(key,encrData));

    }

    



    /**

     * Encrypts a byte array using the specified key.

     * <br/>

     * Algo Specs:

     * Blowfish/ECB/PKCS5Padding

     * 

     * @param key encryption key

     * @param dataBytes bytes

     * @return encrypted bytes

     * @throws Exception

     */

    public static byte[] encryptData(String key, byte[] dataBytes)

            throws Exception

    {



        byte[] keyBytes = key.getBytes();

        String algo = "Blowfish/ECB/PKCS5Padding";

        SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "Blowfish");



        Cipher bfCipher = Cipher.getInstance(algo);

        bfCipher.init(Cipher.ENCRYPT_MODE, secretKey);

        byte[] encrData = bfCipher.doFinal(dataBytes);



        return encrData;

    }



    /**

     * Decrypts an encrypted byte array. 

     * 

     * <br/>

     * Algo Specs:

     * Blowfish/ECB/PKCS5Padding

     * @param key shared key

     * @param encrData 

     * @return

     * @throws Exception

     */

    public static byte[] decryptData(String key, byte[] encrData)

            throws Exception

    {



        byte[] keyBytes = key.getBytes();

        String algo = "Blowfish/ECB/PKCS5Padding";

        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "Blowfish");



        Cipher bfCipher = Cipher.getInstance(algo);

        bfCipher.init(Cipher.DECRYPT_MODE, keySpec);



        byte[] decryptedData = bfCipher.doFinal(encrData);



        return decryptedData;



    }

    

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

    //////UTILITY METHODS////////////////////////////////////////

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

    

    

    /**

     * Converts a string of Hex characters into a corresponding byte array

     * 

     */

    public static byte[] convertHexToBytes(String hexString)

    {

        byte[] byteArr = new byte[hexString.length() / 2];

        for (int i = 0; i < byteArr.length; i++)

        {

            byteArr[i] = (byte) Integer.parseInt(hexString.substring(2 * i,

                    2 * i + 2), 16);

        }

        return byteArr;

    }

    

    /**

     * Converts a string of bytes into the corresponding hex string.

     * 

     * @param val

     * @return

     */

    public static String convertBytesToHex(byte[] val)

    {

        char[] hexChars = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',

                'a', 'b', 'c', 'd', 'e', 'f' };



        // A hex char corresponds to 4 bits. Hence a byte (8 bits)

        // corresponds to two hex chars.

        StringBuffer bufHexVal = new StringBuffer(val.length * 2);

        for (int i = 0; i < val.length; i++)

        {

            byte b = val[i];

            int hiNibble = ((b & 0xf0) >> 4);

            int loNibble = (b & 0x0f);

            bufHexVal.append(hexChars[hiNibble]).append(hexChars[loNibble]);

        }



        String hexString = bufHexVal.toString();

        // System.out.println(hexString);

        return hexString;

    }

    



}