<?php
function encrypt($plaintext, $password)
{
    $method     = "AES-256-CBC";
    $key        = hash('sha256', $password, true);
    $iv         = openssl_random_pseudo_bytes(16);
    $ciphertext = openssl_encrypt($plaintext, $method, $key, OPENSSL_RAW_DATA, $iv);
    $hash       = hash_hmac('sha256', $ciphertext, $key, true);
    return $iv . $hash . $ciphertext;
}
function decrypt($ivHashCiphertext, $password)
{
    $method     = "AES-256-CBC";
    $iv         = substr($ivHashCiphertext, 0, 16);
    $hash       = substr($ivHashCiphertext, 16, 32);
    $ciphertext = substr($ivHashCiphertext, 48);
    $key        = hash('sha256', $password, true);
    if (hash_hmac('sha256', $ciphertext, $key, true) !== $hash)
        return null;
    return openssl_decrypt($ciphertext, $method, $key, OPENSSL_RAW_DATA, $iv);
}

function new_license(){

}

function validate_license($lic){
	$license=explode("-", $lic);
	;
	echo "\n".cntrl_summ($license['2'],0);
	 cntrl_summ($license['2'],0);
}

function cntrl_summ ($num, $num_old, $last_num=false){
	 $x = (int)$num;
	 $s = 0; 
	 while ($x <> 0) {
	 	$s = $s + $x % 10; 
	 	$x = fmod($x ,10 );
	 	echo $x;
	 }
	 if ($x==0) {
 		echo 0;
 	} else echo 1;
}


$k  = '. md5(rand());
$sn = sha1('1314-6685-000-65908');

echo base64_encode(encrypt($k, $sn));
validate_license('1314-6685-000-65908');