53 lines
No EOL
2 KiB
PHP
53 lines
No EOL
2 KiB
PHP
<?php
|
|
|
|
class MyCrypt{
|
|
|
|
private $config;
|
|
|
|
function __construct($cryptinfo) {
|
|
$this->config = $cryptinfo;
|
|
}
|
|
|
|
|
|
public function encrypt($data) {
|
|
|
|
self::check_methods($this->config['enc_method'], $this->config['hash_method']);
|
|
$iv = self::hashIV($this->config['key'], $this->config['hash_method'], openssl_cipher_iv_length($this->config['enc_method']));
|
|
$infostr = sprintf('$%s$%s$', $this->config['enc_method'], $this->config['hash_method']);
|
|
return $infostr . openssl_encrypt($data, $this->config['enc_method'], $this->config['key'], false, $iv);
|
|
}
|
|
|
|
public function decrypt($edata) {
|
|
$e_arr = explode('$', $edata);
|
|
if( count($e_arr) != 4 ) {
|
|
Throw new Exception('Given data is missing crucial sections.');
|
|
}
|
|
$this->config['enc_method'] = $e_arr[1];
|
|
$this->config['hash_method'] = $e_arr[2];
|
|
self::check_methods($this->config['enc_method'], $this->config['hash_method']);
|
|
$iv = self::hashIV($this->config['key'], $this->config['hash_method'], openssl_cipher_iv_length($this->config['enc_method']));
|
|
return openssl_decrypt($e_arr[3], $this->config['enc_method'], $this->config['key'], false, $iv);
|
|
}
|
|
|
|
private static function hashIV($key, $method, $iv_size) {
|
|
$myhash = hash($method, $key, TRUE);
|
|
while( strlen($myhash) < $iv_size ) {
|
|
$myhash .= hash($method, $myhash, TRUE);
|
|
}
|
|
return substr($myhash, 0, $iv_size);
|
|
}
|
|
|
|
private static function check_methods($enc, $hash) {
|
|
|
|
if( ! function_exists('openssl_encrypt') ) {
|
|
Throw new Exception('openssl_encrypt() not supported.');
|
|
} else if( ! in_array($enc, openssl_get_cipher_methods()) ) {
|
|
Throw new Exception('Encryption method ' . $enc . ' not supported.');
|
|
} else if( ! in_array(strtolower($hash), hash_algos()) ) {
|
|
Throw new Exception('Hashing method ' . $hash . ' not supported.');
|
|
}
|
|
}
|
|
|
|
|
|
|
|
} |