I need help!!how can i resolve the error message?

Question

     Security.addProvider(new com.sun.crypto.provider.SunJCE());
KeyGenerator kg = KeyGenerator.getInstance("DES");
Key key = kg.generateKey();
Cipher cipher = Cipher.getInstance("DES");
byte[] data = "Hello World!".getBytes();
out.println("Original data : " + new String(data));
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] result = cipher.doFinal(data);
out.println("Encrypted data: " + new String(result));
               String temp=new String(result); //error occure here!
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] original = cipher.doFinal(temp.getBytes()); //if replace temp.getBytes() to result,that's ok��
out.println("Decrypted data: " + new String(original));
error message��
javax.crypto.BadPaddingException: Given final block not properly padded
     at com.sun.crypto.provider.DESCipher.engineDoFinal(DashoA6275)
     at com.sun.crypto.provider.DESCipher.engineDoFinal(DashoA6275)
     at javax.crypto.Cipher.doFinal(DashoA6275)
and how can i post the key and Encrypted data to columns whose type is varchar in a table in my database,and next time to get the values from my database and translate to key to Decrypte the Encrypted data ?
thanks!!

Answer 1

I presume the no-padding error is happening when you attempt to do the decryption. This means, that in some way, you've modified the encrypted data, and the size of the data is not what the cipher object expects. You don't show all your code here, but most likely, you tried to put result into a string (temp?) and when you do your temp.getBytes(), the array of bytes you're getting back is not the same as the array called result in your post.
Steve