base/rand_util_win.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/rand_util.h"
   6
   7 #include <stdlib.h>
   8
   9 #include "base/basictypes.h"
  10 #include "base/logging.h"
  11
  12 namespace {
  13
  14 uint32 RandUint32() {
  15   uint32 number;
  16   CHECK_EQ(rand_s(&number), 0);
  17   return number;
  18 }
  19
  20 }  // namespace
  21
  22 namespace base {
  23
  24 // NOTE: This function must be cryptographically secure. http://crbug.com/140076
  25 uint64 RandUint64() {
  26   uint32 first_half = RandUint32();
  27   uint32 second_half = RandUint32();
  28   return (static_cast<uint64>(first_half) << 32) + second_half;
  29 }
  30
  31 }  // namespace base