openssl_encrypt 替换 mcrypt_encrypt 函数

/**
* $pwd 要加密的密码
* $key 16位的密钥
* $iv iv
**/
function encryptPwd($pwd, $key) {
    $iv = substr(md5(time()), 0, 16);
    if(function_exists('mcrypt_encrypt')) {
            $encrypted = @mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $pwd, MCRYPT_MODE_CBC, $iv);
    } else {
        $str_padded = $pwd;
        if (strlen($str_padded) % 16) {
            $str_padded = str_pad($str_padded,strlen($str_padded) + 16 - strlen($str_padded) % 16, "\0");
        }
        $encrypted = openssl_encrypt($str_padded, "AES-128-CBC", $key, OPENSSL_NO_PADDING, $iv);
    }
    $enc = base64_encode($iv.$encrypted);

    return $enc;
}