一共有两个文件：AES.php（aes算法类文件）和aesDemo.php（应用实例文件）

aesDemo.php：
例子，

<?php

require_once('./AES.php');
//$aes = new AES();
$aes = new AES(true);// 把加密后的字符串按十六进制进行存储
//$aes = new AES(true,true);// 带有调试信息且加密字符串按十六进制存储
$key = "this is a 32 byte key";// 密钥
$keys = $aes->makeKey($key);
$encode = "123456";// 被加密的字符串
$ct = $aes->encryptString($encode, $keys);
echo "encode = ".$ct."<br>";
$cpt = $aes->decryptString($ct, $keys);
echo "decode = ".$cpt;
?>

例子、AES加密类

<?php

//php aes加密类
class AESMcrypt {
public $iv = null;
public $key = null;
public $bit = 128;
private $cipher;
public function __construct($bit, $key, $iv, $mode) {
if(empty($bit) || empty($key) || empty($iv) || empty($mode))
return NULL;
$this->bit = $bit;
$this->key = $key;
$this->iv = $iv;
$this->mode = $mode;
switch($this->bit) {
case 192:$this->cipher = MCRYPT_RIJNDAEL_192; break;
case 256:$this->cipher = MCRYPT_RIJNDAEL_256; break;
default: $this->cipher = MCRYPT_RIJNDAEL_128;
}
switch($this->mode) {
case 'ecb':$this->mode = MCRYPT_MODE_ECB; break;
case 'cfb':$this->mode = MCRYPT_MODE_CFB; break;
case 'ofb':$this->mode = MCRYPT_MODE_OFB; break;
case 'nofb':$this->mode = MCRYPT_MODE_NOFB; break;
default: $this->mode = MCRYPT_MODE_CBC;
}
}
public function encrypt($data) {
$data = base64_encode(mcrypt_encrypt( $this->cipher, $this->key, $data, $this->mode, $this->iv));
return $data;
}
public function decrypt($data) {
$data = mcrypt_decrypt( $this->cipher, $this->key, base64_decode($data), $this->mode, $this->iv);
$data = rtrim(rtrim($data), "..");
return $data;
}
}
//使用方法
$aes = new AESMcrypt($bit = 128, $key = 'abcdef1234567890', $iv = '0987654321fedcba', $mode = 'cbc');
$c = $aes->encrypt('haowei.me');
var_dump($aes->decrypt($c));

　　例子、附一个可加密可解密类

<?PHP

/**
* AES加密、解密类
* @author hushangming
* www.jbxue.com
* 用法：
* <pre>
* // 实例化类
* // 参数$_bit：格式，支持256、192、128，默认为128字节的
* // 参数$_type：加密/解密方式，支持cfb、cbc、nofb、ofb、stream、ecb，默认为ecb
* // 参数$_key：密钥，默认为abcdefghijuklmno
* $tcaes = new TCAES(); 
* $string = 'laohu';
* // 加密
* $encodeString = $tcaes->encode($string);
* // 解密
* $decodeString = $tcaes->decode($encodeString);
* </pre>
*/
class TCAES{
private $_bit = MCRYPT_RIJNDAEL_256;
private $_type = MCRYPT_MODE_CBC;
//private $_key = 'abcdefghijuklmno0123456789012345';
private $_key = 'abcdefghijuklmno'; // 密钥
private $_use_base64 = true;
private $_iv_size = null;
private $_iv = null;

/**
* @param string $_key 密钥
* @param int $_bit 默认使用128字节
* @param string $_type 加密解密方式
* @param boolean $_use_base64 默认使用base64二次加密
*/
public function __construct($_key = '', $_bit = 128, $_type = 'ecb', $_use_base64 = true){
// 加密字节
if(192 === $_bit){
$this->_bit = MCRYPT_RIJNDAEL_192;
}elseif(128 === $_bit){
$this->_bit = MCRYPT_RIJNDAEL_128;
}else{
$this->_bit = MCRYPT_RIJNDAEL_256;
}
// 加密方法
if('cfb' === $_type){
$this->_type = MCRYPT_MODE_CFB;
}elseif('cbc' === $_type){
$this->_type = MCRYPT_MODE_CBC;
}elseif('nofb' === $_type){
$this->_type = MCRYPT_MODE_NOFB;
}elseif('ofb' === $_type){
$this->_type = MCRYPT_MODE_OFB;
}elseif('stream' === $_type){
$this->_type = MCRYPT_MODE_STREAM;
}else{
$this->_type = MCRYPT_MODE_ECB;
}
// 密钥
if(!empty($_key)){
$this->_key = $_key;
}
// 是否使用base64
$this->_use_base64 = $_use_base64;

$this->_iv_size = mcrypt_get_iv_size($this->_bit, $this->_type);
$this->_iv = mcrypt_create_iv($this->_iv_size, MCRYPT_RAND);
}

/**
* 加密
* @param string $string 待加密字符串
* @return string
*/
public function encode($string){
if(MCRYPT_MODE_ECB === $this->_type){
$encodeString = mcrypt_encrypt($this->_bit, $this->_key, $string, $this->_type); 
}else{
$encodeString = mcrypt_encrypt($this->_bit, $this->_key, $string, $this->_type, $this->_iv);
}
if($this->_use_base64)
$encodeString = base64_encode($encodeString);
return $encodeString;
}

/**
* 解密
* @param string $string 待解密字符串
* @return string
*/
public function decode($string){
if($this->_use_base64)
$string = base64_decode($string);

$string = $this->toHexString($string);
if(MCRYPT_MODE_ECB === $this->_type){
$decodeString = mcrypt_decrypt($this->_bit, $this->_key, $string, $this->_type);
}else{
$decodeString = mcrypt_decrypt($this->_bit, $this->_key, $string, $this->_type, $this->_iv);
}
return $decodeString;
}

/**
* 将$string转换成十六进制
* @param string $string
* @return stream
*/
private function toHexString ($string){
$buf = "";
for ($i = 0; $i < strlen($string); $i++){
$val = dechex(ord($string{$i}));
if(strlen($val)< 2)
$val = "0".$val;
$buf .= $val;
}
return $buf;
}

/**
* 将十六进制流$string转换成字符串
* @param stream $string
* @return string
*/
private function fromHexString($string){
$buf = "";
for($i = 0; $i < strlen($string); $i += 2){
$val = chr(hexdec(substr($string, $i, 2)));
$buf .= $val;
}
return $buf;
}
}