# mcrypt_enc_get_supported_key_sizes

(PHP 4 >= 4.0.2, PHP 5)

mcrypt_enc_get_supported_key_sizes — Returns an array with the supported keysizes of the opened algorithm

### Description

array mcrypt_enc_get_supported_key_sizes ( resource `$td` )

Returns an array with the key sizes supported by the algorithm specified by the encryption descriptor. If it returns an empty array then all key sizes between 1 and mcrypt_enc_get_key_size() are supported by the algorithm.

Example#1 mcrypt_enc_get_supported_key_sizes() example

`<?php
$td = mcrypt_module_open('rijndael-256', '', 'ecb', '');
var_dump(mcrypt_enc_get_supported_key_sizes($td));
?>`

This will print:

    array(3) {
      [0]=>
      int(16)
      [1]=>
      int(24)
      [2]=>
      int(32)
    }