PHP完整的AES加解密算法使用及例子（256位）

<?php
class aes {

// CRYPTO_CIPHER_BLOCK_SIZE 32

private $_secret_key = 'default_secret_key';

public function setKey($key) {
$this->_secret_key = $key;
}

public function encode($data) {
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_256,'',MCRYPT_MODE_CBC,'');
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td),MCRYPT_RAND);
mcrypt_generic_init($td,$this->_secret_key,$iv);
$encrypted = mcrypt_generic($td,$data);
mcrypt_generic_deinit($td);

return $iv . $encrypted;
}

public function decode($data) {
$td = mcrypt_module_open(MCRYPT_RIJNDAEL_256,'',MCRYPT_MODE_CBC,'');
$iv = mb_substr($data,0,32,'latin1');
mcrypt_generic_init($td,$this->_secret_key,$iv);
$data = mb_substr($data,32,mb_strlen($data,'latin1'),'latin1');
$data = mdecrypt_generic($td,$data);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);

return trim($data);
}
}

$aes = new aes();
$aes->setKey('key');

// 加密
$string = $aes->encode('string');
// 解密
$aes->decode($string);
?>