给个参考

function AES_PKCS5_ENCRYPT($text, $key)
{
$alg = MCRYPT_RIJNDAEL_128;
$mode = MCRYPT_MODE_ECB;
$iv_size = mcrypt_get_iv_size($alg, $mode);
$block_size = mcrypt_get_block_size($alg, $mode);
$iv = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM);
$this->iv = $iv;
$input = $this->pkcs5_pad($text, $block_size);
$crypttext = mcrypt_encrypt($alg, $key, $input, $mode, $iv);
return base64_encode($crypttext);
}

function AES_PKCS5_DECRYPT($text, $key)
{
$alg = MCRYPT_RIJNDAEL_128;
$mode = MCRYPT_MODE_ECB;
$text = base64_decode($text);
$decrypted = mcrypt_decrypt($alg, $key, $text, $mode, $this->iv);
$decrypted = $this->pkcs5_unpad($decrypted);
return $decrypted;
}


function pkcs5_pad($text, $blocksize)
{
$pad = $blocksize - (strlen($text) % $blocksize);
return $text . str_repeat(chr($pad), $pad);
}

function pkcs5_unpad($text)
{
$pad = ord($text{strlen($text) - 1});
if ($pad > strlen($text)) return false;
if (strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false;
return substr($text, 0, -1 * $pad);
}