File: rand_util_win.cc

package info (click to toggle)
chromium-browser 57.0.2987.98-1~deb8u1
  • links: PTS, VCS
  • area: main
  • in suites: jessie
  • size: 2,637,852 kB
  • ctags: 2,544,394
  • sloc: cpp: 12,815,961; ansic: 3,676,222; python: 1,147,112; asm: 526,608; java: 523,212; xml: 286,794; perl: 92,654; sh: 86,408; objc: 73,271; makefile: 27,698; cs: 18,487; yacc: 13,031; tcl: 12,957; pascal: 4,875; ml: 4,716; lex: 3,904; sql: 3,862; ruby: 1,982; lisp: 1,508; php: 1,368; exp: 404; awk: 325; csh: 117; jsp: 39; sed: 37
file content (45 lines) | stat: -rw-r--r-- 1,336 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/rand_util.h"

#include <windows.h>
#include <stddef.h>
#include <stdint.h>

// #define needed to link in RtlGenRandom(), a.k.a. SystemFunction036.  See the
// "Community Additions" comment on MSDN here:
// http://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx
#define SystemFunction036 NTAPI SystemFunction036
#include <NTSecAPI.h>
#undef SystemFunction036

#include <algorithm>
#include <limits>

#include "base/logging.h"

namespace base {

// NOTE: This function must be cryptographically secure. http://crbug.com/140076
uint64_t RandUint64() {
  uint64_t number;
  RandBytes(&number, sizeof(number));
  return number;
}

void RandBytes(void* output, size_t output_length) {
  char* output_ptr = static_cast<char*>(output);
  while (output_length > 0) {
    const ULONG output_bytes_this_pass = static_cast<ULONG>(std::min(
        output_length, static_cast<size_t>(std::numeric_limits<ULONG>::max())));
    const bool success =
        RtlGenRandom(output_ptr, output_bytes_this_pass) != FALSE;
    CHECK(success);
    output_length -= output_bytes_this_pass;
    output_ptr += output_bytes_this_pass;
  }
}

}  // namespace base