(PHP 4 = 4.0.2)
Returns an array with the key sizes supported by
the specified algorithm. If it returns an empty array then all
key sizes between 1 and
mcrypt_module_get_algo_key_size()
are supported by the algorithm. The optional
lib_dir
parameter can contain the location where the mode module is on
the system.
See also
mcrypt_enc_get_supported_key_sizes()
which is used on open encryption modules.