While not specified in the description, this function, just like mcrypt_enc_get_key_size(), returns the cipher's largest key size in BYTES.
(PHP 4, PHP 5, PHP 7)
mcrypt_get_key_size — Gets the key 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_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().
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".
Returns the maximum supported key size of the algorithm in bytes
or FALSE on failure.
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.
The above example will output:
24
While not specified in the description, this function, just like mcrypt_enc_get_key_size(), returns the cipher's largest key size in BYTES.