mfbt/RandomNum.h
author Sylvestre Ledru <sledru@mozilla.com>
Fri, 30 Nov 2018 11:46:48 +0100
changeset 505383 6f3709b3878117466168c40affa7bca0b60cf75b
parent 499515 f3d23a7bcbb6e30a5d7368882fdf1b04498d9bdf
permissions -rw-r--r--
Bug 1511181 - Reformat everything to the Google coding style r=ehsan a=clang-format # ignore-this-changeset

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

/* Routines for generating random numbers */

#ifndef mozilla_RandomNum_h_
#define mozilla_RandomNum_h_

#include "mozilla/Maybe.h"
#include "mozilla/Types.h"

namespace mozilla {

/**
 *  Generate a cryptographically secure random 64-bit unsigned number using the
 *  best facilities available on the current OS.
 *
 *  Useful whenever a secure random number is needed and NSS isn't available.
 *  (Perhaps because it hasn't been initialized yet)
 *
 *  Current mechanisms:
 *    Windows: RtlGenRandom()
 *    Android, Darwin, DragonFly, FreeBSD, OpenBSD, NetBSD: arc4random()
 *    Linux: getrandom() if available, "/dev/urandom" otherwise
 *    Other Unix: "/dev/urandom"
 *
 */
MFBT_API Maybe<uint64_t> RandomUint64();

}  // namespace mozilla

#endif  // mozilla_RandomNum_h_