var/opt/nydus/ops/oscrypto/_rand.py000064400000002020147205253660013424 0ustar00# coding: utf-8 from __future__ import unicode_literals, division, absolute_import, print_function import os from ._errors import pretty_message from ._types import type_name, int_types __all__ = [ 'rand_bytes', ] def rand_bytes(length): """ Returns a number of random bytes suitable for cryptographic purposes :param length: The desired number of bytes :raises: ValueError - when any of the parameters contain an invalid value TypeError - when any of the parameters are of the wrong type OSError - when an error is returned by OpenSSL :return: A byte string """ if not isinstance(length, int_types): raise TypeError(pretty_message( ''' length must be an integer, not %s ''', type_name(length) )) if length < 1: raise ValueError('length must be greater than 0') if length > 1024: raise ValueError('length must not be greater than 1024') return os.urandom(length)