php加密解密实用类分享_php实例

代码如下:

class crypt {

private $skey;

public function __construct($key) {
$this->skey = hash("md5", $key, true); //32位skey
}

public function safe_b64encode($string) {
$data = base64_encode($string);
$data = str_replace(array('+', '/', '='), array('-', '_', ''), $data);
return $data;
}

public function safe_b64decode($string) {
$data = str_replace(array('-', '_'), array('+', '/'), $string);
$mod4 = strlen($data) % 4;
if ($mod4) {
$data .= substr('====', $mod4);
}
return base64_decode($data);
}

public function encode($value) {
if (!$value) {
return false;
}
$text = $value;
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
$crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $this->skey, $text, MCRYPT_MODE_ECB, $iv);
return trim($this->safe_b64encode($crypttext));
}

public function decode($value) {
if (!$value) {
return false;
}
$crypttext = $this->safe_b64decode($value);
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
$decrypttext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $this->skey, $crypttext, MCRYPT_MODE_ECB, $iv);
return trim($decrypttext);
}

}