PHP Android iOS mutual compatible AES encryption algorithm

HTTPS has not been used for password transmission in app project. Considering the user's privacy, AES is used to encrypt the password for the time being, and it can also be used for encryption interaction between mobile terminal and server terminal later.
PHP free version of phpaes project, mobile decoding all kinds of wrong.
Finally, I find PHP Android IOS, and mutually encrypt and decrypt the normal AES encryption algorithm code.
AES encryption algorithm of PHP:

[codesyntax lang=”php”]

<?php
class MCrypt {
    private $hex_iv = ‘00000000000000000000000000000000‘; # converted JAVA byte code in to HEX and placed it here           
    private $key = ‘U1MjU1M0FDOUZ.Qz‘; #Same as in JAVA
    function __construct() {
        $this->key = hash(‘sha256‘, $this->key, true);
        //echo $this->key.‘<br/>‘;
    }
    function encrypt($str) {   
        $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, ‘‘, MCRYPT_MODE_CBC, ‘‘);
        mcrypt_generic_init($td, $this->key, $this->hexToStr($this->hex_iv));
        $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
        $pad = $block - (strlen($str) % $block);
        $str .= str_repeat(chr($pad), $pad);
        $encrypted = mcrypt_generic($td, $str);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);    
        return base64_encode($encrypted);
    }
    function decrypt($code) {    
        $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, ‘‘, MCRYPT_MODE_CBC, ‘‘);
        mcrypt_generic_init($td, $this->key, $this->hexToStr($this->hex_iv));
        $str = mdecrypt_generic($td, base64_decode($code));
        $block = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
        mcrypt_generic_deinit($td);
        mcrypt_module_close($td);    
        return $this->strippadding($str);           
    }
    /*
      For PKCS7 padding
     */
    private function addpadding($string, $blocksize = 16) {
        $len = strlen($string);
        $pad = $blocksize - ($len % $blocksize);
        $string .= str_repeat(chr($pad), $pad);
        return $string;
    }
    private function strippadding($string) {
        $slast = ord(substr($string, -1));
        $slastc = chr($slast);
        $pcheck = substr($string, -$slast);
        if (preg_match("/$slastc{" . $slast . "}/", $string)) {
            $string = substr($string, 0, strlen($string) - $slast);
            return $string;
        } else {
            return false;
        }
    }
function hexToStr($hex)
{
    $string=‘‘;
    for ($i=0; $i < strlen($hex)-1; $i+=2)
    {
        $string .= chr(hexdec($hex[$i].$hex[$i+1]));
    }
    return $string;
}
}
$encryption = new MCrypt();
echo $encryption->encrypt(‘123456‘) . "<br/>";
echo $encryption->decrypt(‘tpyxISJ83dqEs3uw8bN/+w==‘);

?>

[/codesyntax]
AES encryption algorithm of Java:
[codesyntax lang=”java”]

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import android.util.Base64;
/**
 * @author vipin.cb , [email protected] <br>
 *         Sep 27, 2013, 5:18:34 PM <br>
 *         Package:- <b>com.veebow.util</b> <br>
 *         Project:- <b>Veebow</b>
 *         <p>
 */
public class AESCrypt {
    private final Cipher cipher;
    private final SecretKeySpec key;
    private AlgorithmParameterSpec spec;
    public static final String SEED_16_CHARACTER = "U1MjU1M0FDOUZ.Qz";
    public AESCrypt() throws Exception {
        // hash password with SHA-256 and crop the output to 128-bit for key
        MessageDigest digest = MessageDigest.getInstance("SHA-256");
        digest.update(SEED_16_CHARACTER.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");
        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");
        return decryptedText;
    }
}

[/codesyntax]
AES encryption algorithm of IOS:
https://github.com/Gurpartap/AESCrypt-ObjC
Stackoverflow reference
http://stackoverflow.com/questions/5928915/wanted-compatible-aes-code-encrypt-decrypt-for-iphone-android-windows-xp
http://stackoverflow.com/questions/19196728/aes-128-encryption-in-java-decryption-in-php
AES encryption algorithm compatible with PHP Android IOS