AES algorithm differs in PHP from Android and iOS - php

Question

Hi I am currently working for encryption and decryption for a string using AES algorithm in PHP and Android. I got the similar values in iOS and in Android. But I cant get the same output in PHP. It shows some other encrypted string. I want to achieve the same result in all iOS, Android and PHP. At the moment iOS and Android are working fine. But I cant fix in PHP.
Please check the screenshots and compare the values. I used "Android" as value and "abcdef" as key.
<?php
$Pass = "abcdef";
$Clear = "android";
$crypted = mc_encrypt($Clear, $Pass);
echo "Encrypred: ".$crypted."</br>";
$newClear = mc_decrypt($crypted, $Pass);
echo "Decrypred: ".$newClear."</br>";
function mc_encrypt($encrypt, $mc_key) {
$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB), MCRYPT_RAND);
$passcrypt = trim(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $mc_key, trim($encrypt), MCRYPT_MODE_ECB, $iv));
$encode = base64_encode($passcrypt);
return $encode;
}
function mc_decrypt($decrypt, $mc_key) {
$decoded = base64_decode($decrypt);
$iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB), MCRYPT_RAND);
$decrypted = trim(mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $mc_key, trim($decoded), MCRYPT_MODE_ECB, $iv));
return $decrypted;
}
?>
I get the following output
Encrypred: +NzljOmN0msNkWr/cst11Q==
Decrypred: android
Below code is used in Android
package com.example.aesalg;
import java.security.MessageDigest;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;
public class AESCrypt {
private final Cipher cipher;
private final SecretKeySpec key;
private AlgorithmParameterSpec spec;
public AESCrypt(String password) throws Exception
{
// hash password with SHA-256 and crop the output to 128-bit for key
MessageDigest digest = MessageDigest.getInstance("SHA-256");
digest.update(password.getBytes("UTF-8"));
byte[] keyBytes = new byte[32];
System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);
cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
key = new SecretKeySpec(keyBytes, "AES");
spec = getIV();
}
public AlgorithmParameterSpec getIV()
{
byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
IvParameterSpec ivParameterSpec;
ivParameterSpec = new IvParameterSpec(iv);
return ivParameterSpec;
}
public String encrypt(String plainText) throws Exception
{
cipher.init(Cipher.ENCRYPT_MODE, key, spec);
byte[] encrypted = cipher.doFinal(plainText.getBytes("UTF-8"));
String encryptedText = new String(Base64.encode(encrypted, Base64.DEFAULT), "UTF-8");
System.out.println("Encrypt Data"+ encryptedText);
return encryptedText;
}
public String decrypt(String cryptedText) throws Exception
{
cipher.init(Cipher.DECRYPT_MODE, key, spec);
byte[] bytes = Base64.decode(cryptedText, Base64.DEFAULT);
byte[] decrypted = cipher.doFinal(bytes);
String decryptedText = new String(decrypted, "UTF-8");
System.out.println("Encrypt Data"+ decryptedText);
return decryptedText;
}
}

Answer 1

You are using CBC in your Android app and ECB in the PHP code. See wikipedia for more details.
Try to change mcrypt parameter to MCRYPT_MODE_CBC. Also I believe mcrypt is always using zero padding (I'm not a PHP expert) so on the Android side you have to use "AES/CBC/ZeroBytePadding"

Answer 2

in php try this code
public function encrypt($string, $key)
{
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');
$block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB);
$pad = $block - (strlen($string) % $block);
$string .= str_repeat(chr($pad), $pad);
mcrypt_generic_init($td, $key, 'fedcba9876543210');
$encrypted = mcrypt_generic($td, $string);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
return $encrypted;
}
function decrypt($string, $key)
{
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_ECB, '');
mcrypt_generic_init($td, $key, 'fedcba9876543210');
$decrypted = mdecrypt_generic($td, $string);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);
return $decrypted;
}