Bad Padding Exception using AES/ECB/PKCS5Padding

Question

Hi, I need some help Tryng to crypt and decrypt a String using AES/ECB/PKCS5Padding
I paste my code below
Crypt
Cipher cipher;
         byte[] pass=new byte[]{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}; // just for example
        SecretKeySpec key = new SecretKeySpec(pass, "AES");
        cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, key);        
        byte[] utf8 = da_cifrare.getBytes("utf-8");
        byte[] enc = cipher.doFinal(utf8);
        String cifrata =new String (Base64.encodeBase64(enc));
        return cifrata;
And on the other side Decrypt
Cipher decipher;
           byte[] pass=new byte[]{1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}; // just for example
           SecretKeySpec key = new SecretKeySpec(pass, "AES");
           decipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
           decipher.init(Cipher.DECRYPT_MODE, key); 
           byte[] buf =Base64.decodeBase64(da_decifrare.getBytes("utf-8"));
           byte[] recoveredBytes = decipher.doFinal(buf);
           String in_chiaro = new String (recoveredBytes,"utf-8");
           return (in_chiaro);I'm getting Bad padding exception when I try to Decrypt, any ideas ??

Answer 1

Nothing obviously wrong but we have no view of your Base64 encoder and decoder. You should check
a) that the bytes of your key are the same in both methods
b) that the bytes resulting in your decrypt methodbyte[] buf =Base64.decodeBase64(da_decifrare.getBytes("utf-8"));are exactly the same as those created in the encrypt method using  byte[] enc = cipher.doFinal(utf8);
      Note - since Base64 consists of only ASCII characters you should use String cifrata =new String (Base64.encodeBase64(enc),"ASCII");and byte[] buf =Base64.decodeBase64(da_decifrare.getBytes("ASCII"));though this flaw should not be the cause of your exception.
Edited by: sabre150 on Dec 15, 2009 12:32 PM