mcrypt_module_get_algo_key_size Returns the maximum supported keysize of the opened mode &reftitle.description; intmcrypt_module_get_algo_key_size stringalgorithm stringlib_dir Gets the maximum supported keysize of the opened mode. &reftitle.parameters; algorithm The algorithm name. lib_dir This optional parameter can contain the location where the mode module is on the system. &reftitle.returnvalues; This function returns the maximum supported key size of the algorithm specified in bytes.