(PHP 4, PHP 5)
mcrypt_get_key_size — Gets the key size of the specified cipher
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).
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_key_size() Example
<?php
echo mcrypt_get_key_size('tripledes', 'ecb');
?>
The example above shows how to use this function when linked against libmcrypt 2.4.x or 2.5.x.
以上例程会输出：
24