You should explain that the block size is return in BYTES, not the more commonly used unit, bits. Many readers are not going to know the DES block size and figure this out on their own.
(PHP 4, PHP 5, PHP 7)
mcrypt_get_block_size — Gets the block size of the specified cipher
$cipher
)$cipher
, string $mode
)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_block_size() is used to get the
size of a block of the specified cipher (in
combination with an encryption mode).
It is more useful to use the mcrypt_enc_get_block_size() function as this uses the resource returned by mcrypt_module_open().
cipherOne of the MCRYPT_ciphername constants, or the name of the algorithm as string.
modeOne of the MCRYPT_MODE_modename constants, or one of the following strings: "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".
Gets the block size, as an integer.
Example #1 mcrypt_get_block_size() example
This example shows how to use this function when linked against libmcrypt 2.4.x and 2.5.x.
<?php
echo mcrypt_get_block_size('tripledes', 'ecb'); // 8
?>
You should explain that the block size is return in BYTES, not the more commonly used unit, bits. Many readers are not going to know the DES block size and figure this out on their own.