PHP Manual: mcrypt_get_key

mcrypt_get_key_size

(PHP 3 >= 3.0.8, PHP 4, PHP 5)

mcrypt_get_key_size -- Get the key size of the specified cipher

Description

int mcrypt_get_key_size ( int cipher )

int mcrypt_get_key_size ( string cipher, string module )

The first prototype is when linked against libmcrypt 2.2.x, the second when linked against libmcrypt 2.4.x or 2.5.x.

mcrypt_get_key_size() is used to get the size of a key of the specified cipher (in combination with an encryption mode).

This example shows how to use this function when linked against libmcrypt 2.4.x and 2.5.x. It is more useful to use the mcrypt_enc_get_key_size() function as this uses the resource returned by mcrypt_module_open().

Example 1. mcrypt_get_block_size() example

<?php
    echo mcrypt_get_key_size('tripledes', 'ecb');
?>

Prints:
24

See also: mcrypt_get_block_size(), mcrypt_end_get_key_size() and mcrypt_encrypt().