Encryption using Bouncy Castle API

code snippet for encrypting and decrypting strings in java. We will be using the Bouncy Castle API for this purpose and PaddedBufferedBlockCipher cipher with a BlowFish engine for encryption and decryption. For this code snippet to work, the jar file encryption.jar should be downloaded from bouncy castle web site and placed in WEB-INF\lib.

• Bouncy castle Crypto APIs  
• http://www.bouncycastle.org/latest_releases.html
• bcprov-jdk15-146

import java.util.Properties;

import org.bouncycastle.crypto.CryptoException;
import org.bouncycastle.crypto.engines.BlowfishEngine;
import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
import org.bouncycastle.crypto.params.KeyParameter;
import org.bouncycastle.util.encoders.Base64;

public class SecurityUtil extends Properties {

 public static void main(String[] args) {
  String originalString = "fall2008"; // String to be encrypted.
  String keyString = "secretkey"; // A secret key that is used during encryption and decryption
  try {
   String encryptedString = encrypt(originalString, keyString);
   System.out.println("Original String: " + originalString);
   System.out.println("Encrypted String: " + encryptedString);
   String decryptedString = decrypt(encryptedString, keyString);
   System.out.println("Decrypted String: " + decryptedString);
  } catch (Exception e) {
   e.printStackTrace();
  }

 }

 public static String decrypt(String name, String keyString)
  throws Exception {
  BlowfishEngine engine = new BlowfishEngine();
  PaddedBufferedBlockCipher cipher =
   new PaddedBufferedBlockCipher(engine);
  StringBuffer result = new StringBuffer();
  KeyParameter key = new KeyParameter(keyString.getBytes());
  cipher.init(false, key);
  byte out[] = Base64.decode(name);
  byte out2[] = new byte[cipher.getOutputSize(out.length)];
  int len2 = cipher.processBytes(out, 0, out.length, out2, 0);
  cipher.doFinal(out2, len2);
  String s2 = new String(out2);
  for (int i = 0; i < s2.length(); i++) {
   char c = s2.charAt(i);
   if (c != 0) {
    result.append(c);
   }
  }

  return result.toString();
 }

 public static String encrypt(String value, String keyString)
  throws Exception {
  BlowfishEngine engine = new BlowfishEngine();
  PaddedBufferedBlockCipher cipher =
   new PaddedBufferedBlockCipher(engine);
  KeyParameter key = new KeyParameter(keyString.getBytes());
  cipher.init(true, key);
  byte in[] = value.getBytes();
  byte out[] = new byte[cipher.getOutputSize(in.length)];
  int len1 = cipher.processBytes(in, 0, in.length, out, 0);
  try {
   cipher.doFinal(out, len1);
  } catch (CryptoException e) {
   e.printStackTrace();
   throw new Exception(e.getMessage());
  }
  String s = new String(Base64.encode(out));
  return s;
 }
}