int mcrypt_get_key_size(int $cipher, string $cipher, string $mode)
This function has been DEPRECATED as of PHP 7.1.0. Relying on this function is highly discouraged.
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().
Returns the maximum supported key size of the algorithm in bytes or
FALSE on failure.
- int $cipher: One of the
MCRYPT_ciphernameconstants, or the name of the algorithm as string.
- string $cipher: One of the
MCRYPT_MODE_modenameconstants, or one of the following strings: "ecb", "cbc", "cfb", "ofb", "nofb" or "stream".
- string $mode:
Example #1 mcrypt_get_key_size() Example
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: