php Mcrypt

<?php
$str = '123123dscxcbVdkgtbC+ELltScLRgM+gsRyzzA7Y=encode';
$a = authCrypt($str, md5("miyaobunenggaosuni") , 'decode' );
echo($a);
/**
* Mcrypt 加密/解密
* @param type $date 要加密和解密的数据
* @param type $key 密钥
* @param type $mode  encode 默认为加密/decode 为解密
* @return type
*/

function authCrypt($date, $key , $mode = 'encode') {
if ($mode == 'decode') {
$pos = strpos($date,'encode');
if($pos) {
$date = substr($date, 0,$pos);
}
$date = base64_decode($date);
}
if (function_exists('mcrypt_create_iv')) {
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
}
if (isset($iv) && $mode == 'encode') {
$passcrypt = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $date, MCRYPT_MODE_ECB, $iv);
} elseif (isset($iv) && $mode == 'decode') {
$passcrypt = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $date, MCRYPT_MODE_ECB, $iv);
}
if ($mode == 'encode') {
$passcrypt = base64_encode($passcrypt).$mode;
}
return $passcrypt;
}

?>