Decrypt the encrypted password

Question

Hi there,
I have been scratching my head for some time to fix one issue. We are planning to change the plateform/technology and we need to bring over existing login to new system. In order to have the same password I need to decrypt the password before I send it to new system. When we stored the password, it encrypts them and stores it in database. I am using following code to decrypt it. it's not worlking . This is error I am getting.
Given final block not properly padded
Here is some more information:
Key is :javax.crypto.spec.SecretKeySpec@18f3a
Format is :RAW
getAlgorithm() is :DES
String encrypted = abcdefgh
Provider is: com.sun.crypto.provider.SunJCE()
This is my code to decrypt which throws error " Given final block not properly padded" :
public String decrypt(String encrypted){
          Cipher ci = null;
          byte [] result = null;
          try {
               ci = Cipher.getInstance("DES");
               ci.init(Cipher.DECRYPT_MODE, key);
               System.out.println("CryptoUtil()" +"before hexToByteArray. Byte Data: "+encrypted);
               byte [] encryptedData = hexToByteArray(encrypted, false);
               //Log.out("CryptoUtil()" +"after hexToByteArray. lenth: "+ encryptedData.length);
               result = ci.doFinal(encryptedData);
          catch (Exception e) {
               System.out.println("CryptoUtil()" +"ERROR: "+ e.getMessage());
               return encrypted;
          String strResult = new String(result);
          return strResult;
Please help.
Thank you.

Answer 1

These are the two values I am getting for encrypted password:
97654de7857cd9aab331995cba044fc6
a125a6b2a71e23adc002ac7fbe1a1042
Is this a hex code?
I think the key is: abcdefgh
This is my code to encrypt and decrypt:
      * empty constructor
      * @param keydata
     public CryptoUtil(String keydata){
          if (keydata.trim().equals("")){
               logDebug("CryptoUtil()" +" Constructor didn't get a valid key!");
               usage();
               System.exit(0);
          }else{
               keyBytes = keydata.getBytes();
               key = new SecretKeySpec(keyBytes, 0, keyBytes.length, "DES");
          try {
               Provider sp = new com.sun.crypto.provider.SunJCE();
               //logDebug("CryptoUtil() " + sp.getInfo());
                Security.addProvider(sp);
              }catch (Exception ex) {
                     logDebug("CryptoUtil() " +"Problem loading crypto provider \n error:"+ex.getMessage());
               usage();
                System.exit(0);
      * Encrypt
      * @param s
     public String encrypt(String s){
          Cipher ci = null;
              byte [] result = null;
              try {
               ci = Cipher.getInstance("DES");
               ci.init(Cipher.ENCRYPT_MODE, key);
               result = ci.doFinal(s.getBytes());
              }catch (Exception e) {
                    logDebug("CryptoUtil()" +"ERROR: "+ e.getMessage());
          String strResult = byteArrayToHex(result);
              return strResult;
      * decrypt a card number
      * @param encrypted
     public String decrypt(String encrypted){
          Cipher ci = null;
              byte [] result = null;
              try {
               ci = Cipher.getInstance("DES");
               ci.init(Cipher.DECRYPT_MODE, key);
               //Log.out("CryptoUtil()" +"before hexToByteArray. Byte Data: "+encrypted);
               byte [] encryptedData = hexToByteArray(encrypted, false);
               //Log.out("CryptoUtil()" +"after hexToByteArray. lenth: "+ encryptedData.length);
               result = ci.doFinal(encryptedData);
              catch (Exception e) {
               logError("CryptoUtil()" +"ERROR: "+ e.getMessage());
               return encrypted;
          String strResult = new String(result);
          return strResult;
     static final String hexDigitChars = "0123456789abcdef";
      * @param a
     public static final String byteArrayToHex(byte [] a) {
          int hn, ln, cx;
          StringBuffer buf = new StringBuffer(a.length * 2);
          for(cx = 0; cx < a.length; cx++) {
                hn = ((int)(a[cx]) & 0x00ff) / 16;
                ln = ((int)(a[cx]) & 0x000f);
                buf.append(hexDigitChars.charAt(hn));
                buf.append(hexDigitChars.charAt(ln));
                buf.append(' ');
         return buf.toString();
      * @param str
      * @param rev
     public static final byte [] hexToByteArray(String str, boolean rev) {
          StringBuffer acc = new StringBuffer(str.length() + 1);
          int cx, rp, ff, val;
          char [] s = new char[str.length()];
          str.toLowerCase().getChars(0, str.length(), s, 0);
          for(cx = str.length() - 1, ff = 0; cx >= 0; cx--) {
          if (hexDigitChars.indexOf(s[cx]) >= 0) {
               acc.append(s[cx]);
               ff++;
           }else {
               if ((ff % 2) > 0) acc.append('0');
                    ff = 0;
          if ((ff % 2) > 0) acc.append('0');
          byte [] ret = new byte[acc.length() / 2];
          for(cx = 0, rp = ret.length - 1; cx < acc.length(); cx++, rp--) {
                val = hexDigitChars.indexOf(acc.charAt(cx));
                cx++;
                val += 16 * hexDigitChars.indexOf(acc.charAt(cx));
                ret[rp] = (byte)val;
          if (rev) {
                byte tmp;
                int fx, bx;
                for(fx = 0, bx = ret.length - 1; fx < (ret.length / 2); fx++, bx--) {
                    tmp = ret[bx];
                    ret[bx] = ret[fx];
                    ret[fx] = tmp;
          return ret;
Will that give you any more information to help me?