зеркало из https://github.com/mozilla/gecko-dev.git
162 строки
4.2 KiB
C++
162 строки
4.2 KiB
C++
/* -*- 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/. */
|
|
|
|
#include "mozilla/RandomNum.h"
|
|
|
|
#include <fcntl.h>
|
|
#ifdef XP_UNIX
|
|
# include <unistd.h>
|
|
#endif
|
|
|
|
#if defined(XP_WIN)
|
|
|
|
// Microsoft doesn't "officially" support using RtlGenRandom() directly
|
|
// anymore, and the Windows headers assume that __stdcall is
|
|
// the default calling convention (which is true when Microsoft uses this
|
|
// function to build their own CRT libraries).
|
|
|
|
// We will explicitly declare it with the proper calling convention.
|
|
|
|
# include "minwindef.h"
|
|
# define RtlGenRandom SystemFunction036
|
|
extern "C" BOOLEAN NTAPI RtlGenRandom(PVOID RandomBuffer,
|
|
ULONG RandomBufferLength);
|
|
|
|
#endif
|
|
|
|
#if defined(ANDROID) || defined(XP_DARWIN) || defined(__DragonFly__) || \
|
|
defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
|
|
# include <stdlib.h>
|
|
# define USE_ARC4RANDOM
|
|
#endif
|
|
|
|
#if defined(__linux__)
|
|
# include <linux/random.h> // For GRND_NONBLOCK.
|
|
# include <sys/syscall.h> // For SYS_getrandom.
|
|
|
|
// Older glibc versions don't define SYS_getrandom, so we define it here if
|
|
// it's not available. See bug 995069.
|
|
# if defined(__x86_64__)
|
|
# define GETRANDOM_NR 318
|
|
# elif defined(__i386__)
|
|
# define GETRANDOM_NR 355
|
|
# elif defined(__aarch64__)
|
|
# define GETRANDOM_NR 278
|
|
# elif defined(__arm__)
|
|
# define GETRANDOM_NR 384
|
|
# elif defined(__powerpc__)
|
|
# define GETRANDOM_NR 359
|
|
# elif defined(__s390__)
|
|
# define GETRANDOM_NR 349
|
|
# elif defined(__mips__)
|
|
# include <sgidefs.h>
|
|
# if _MIPS_SIM == _MIPS_SIM_ABI32
|
|
# define GETRANDOM_NR 4353
|
|
# elif _MIPS_SIM == _MIPS_SIM_ABI64
|
|
# define GETRANDOM_NR 5313
|
|
# elif _MIPS_SIM == _MIPS_SIM_NABI32
|
|
# define GETRANDOM_NR 6317
|
|
# endif
|
|
# endif
|
|
|
|
# if defined(SYS_getrandom)
|
|
// We have SYS_getrandom. Use it to check GETRANDOM_NR. Only do this if we set
|
|
// GETRANDOM_NR so tier 3 platforms with recent glibc are not forced to define
|
|
// it for no good reason.
|
|
# if defined(GETRANDOM_NR)
|
|
static_assert(GETRANDOM_NR == SYS_getrandom,
|
|
"GETRANDOM_NR should match the actual SYS_getrandom value");
|
|
# endif
|
|
# else
|
|
# define SYS_getrandom GETRANDOM_NR
|
|
# endif
|
|
|
|
# if defined(GRND_NONBLOCK)
|
|
static_assert(GRND_NONBLOCK == 1,
|
|
"If GRND_NONBLOCK is not 1 the #define below is wrong");
|
|
# else
|
|
# define GRND_NONBLOCK 1
|
|
# endif
|
|
|
|
#endif // defined(__linux__)
|
|
|
|
namespace mozilla {
|
|
|
|
/*
|
|
* Note - Bug 1500115 has been opened to discuss simplifying or improving
|
|
* this function in the future; however, the function is secure as-is right
|
|
* now. Further improvements may be made to reduce complexity, improve
|
|
* robustness, or take advantage of OS-specific API improvements as they
|
|
* become available.
|
|
*
|
|
*/
|
|
|
|
MFBT_API Maybe<uint64_t> RandomUint64() {
|
|
#if defined(XP_WIN)
|
|
|
|
uint64_t result = 0;
|
|
if (!RtlGenRandom(&result, sizeof(result))) {
|
|
return Nothing();
|
|
}
|
|
|
|
return Some(result);
|
|
|
|
#elif defined(USE_ARC4RANDOM) // defined(XP_WIN)
|
|
|
|
return Some((static_cast<uint64_t>(arc4random()) << 32) | arc4random());
|
|
|
|
#elif defined(XP_UNIX) // defined(USE_ARC4RANDOM)
|
|
|
|
uint64_t result = 0;
|
|
|
|
# if defined(__linux__)
|
|
|
|
long bytesGenerated =
|
|
syscall(SYS_getrandom, &result, sizeof(result), GRND_NONBLOCK);
|
|
|
|
if ((bytesGenerated > 0) &&
|
|
(static_cast<unsigned long>(bytesGenerated) == sizeof(result))) {
|
|
return Some(result);
|
|
}
|
|
|
|
// Fall-through to UNIX behavior if failed
|
|
|
|
# endif // defined(__linux__)
|
|
|
|
int fd = open("/dev/urandom", O_RDONLY);
|
|
if (fd < 0) {
|
|
return Nothing();
|
|
}
|
|
|
|
ssize_t bytesRead = read(fd, &result, sizeof(result));
|
|
|
|
close(fd);
|
|
|
|
if (bytesRead < 0) {
|
|
return Nothing();
|
|
}
|
|
|
|
if (static_cast<size_t>(bytesRead) != sizeof(result)) {
|
|
return Nothing();
|
|
}
|
|
|
|
return Some(result);
|
|
|
|
#else // defined(XP_UNIX)
|
|
# error "Platform needs to implement RandomUint64()"
|
|
#endif
|
|
}
|
|
|
|
MFBT_API uint64_t RandomUint64OrDie() {
|
|
Maybe<uint64_t> maybeRandomNum = RandomUint64();
|
|
|
|
MOZ_RELEASE_ASSERT(maybeRandomNum.isSome());
|
|
|
|
return maybeRandomNum.value();
|
|
}
|
|
|
|
} // namespace mozilla
|