Android和PHP加密/解密 - 填充问题

Question

Used code on iOS fine and trying to translate code to Android we have the following however seem to have a padding issue, can anyone offer a hand.

Using a MD5 as key

Java (Android)

public class AES256Cipher {

    public static byte[] ivBytes = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };


    public static String AES_Encode(String str, String key) throws java.io.UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {

        byte[] textBytes = str.getBytes("UTF-8");
        AlgorithmParameterSpec ivSpec = new IvParameterSpec(ivBytes);
             SecretKeySpec newKey = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
             Cipher cipher = null;
        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, newKey, ivSpec);

        return Base64.encodeToString(cipher.doFinal(textBytes), 0);
    }

    public static String AES_Decode(String str, String key) throws java.io.UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {

        byte[] textBytes =Base64.decode(str,0);
        //byte[] textBytes = str.getBytes("UTF-8");
        AlgorithmParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        SecretKeySpec newKey = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, newKey, ivSpec);
        return new String(cipher.doFinal(textBytes), "UTF-8");
    }
}

PHP

<?php
function encrypt ($key, $value)
{                
    $padSize = 16 - (strlen ($value) % 16) ;
    $value = $value . str_repeat (chr ($padSize), $padSize) ;
    $output = mcrypt_encrypt (MCRYPT_RIJNDAEL_128, $key, $value, MCRYPT_MODE_CBC, str_repeat(chr(0),16)) ;                
    return base64_encode ($output) ;        
}

function decrypt ($key, $value)        
{                       
    $value = base64_decode ($value) ;                
    $output = mcrypt_decrypt (MCRYPT_RIJNDAEL_128, $key, $value, MCRYPT_MODE_CBC, str_repeat(chr(0),16)) ;                

    $valueLen = strlen ($output) ;
    if ( $valueLen % 16 > 0 )
        $output = "";

    $padSize = ord ($output{$valueLen - 1}) ;
    if ( ($padSize < 1) or ($padSize > 16) )
        $output = "";                // Check padding.                

    for ($i = 0; $i < $padSize; $i++)
    {
        if ( ord ($output{$valueLen - $i - 1}) != $padSize )
            $output = "";
    }
    $output = substr ($output, 0, $valueLen - $padSize) ;

    return $output;        
} 

?>

The output on Java side works fine however when the code is send to PHP you get an output with remainder which makes us think its a padding issue, any help would be great.

Answer 1

I know this is probably 4 years too late, but I wonder if my question/answer might help to solve this:

RSA Encryption disparity between Android and Java environments