mcrypt_enc_get_supported_key_sizes(3) php man page | unix.com

MCRYPT_ENC_GET_SUPPORTED_KEY_SIZES(3)					 1				     MCRYPT_ENC_GET_SUPPORTED_KEY_SIZES(3)

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

SYNOPSIS
       array mcrypt_enc_get_supported_key_sizes (resource  $td)

DESCRIPTION
	Gets the supported key sizes of the opened algorithm.

PARAMETERS
	      o $td
		- The encryption descriptor.

RETURN VALUES
	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(3) are supported by the algorithm.

EXAMPLES
       Example #1

	      mcrypt_enc_get_supported_key_sizes(3) example

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

	      The above example will output:

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

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