1/*
2 * Copyright (C) 2011 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY GOOGLE, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "OSRandomSource.h"
28
29#include <stdint.h>
30#include <stdlib.h>
31
32#if OS(SYMBIAN)
33#include <e32math.h>
34#endif
35
36#if OS(UNIX)
37#include <fcntl.h>
38#include <unistd.h>
39#endif
40
41#if OS(WINDOWS)
42#include <windows.h>
43#include <wincrypt.h> // windows.h must be included before wincrypt.h.
44#endif
45
46namespace WTF {
47
48#if USE(OS_RANDOMNESS)
49void cryptographicallyRandomValuesFromOS(unsigned char* buffer, size_t length)
50{
51#if OS(SYMBIAN)
52    TInt random;
53    while (length > sizeof(random)) {
54        random = Math::Random();
55        memcpy(buffer, &random, sizeof(random));
56        length -= sizeof(random);
57        buffer += sizeof(random);
58    }
59    if (length > 0) {
60        random = Math::Random();
61        memcpy(buffer, &random, length);
62    }
63#elif OS(UNIX)
64    int fd = open("/dev/urandom", O_RDONLY, 0);
65    if (fd < 0)
66        CRASH(); // We need /dev/urandom for this API to work...
67
68    if (read(fd, buffer, length) != static_cast<ssize_t>(length))
69        CRASH();
70
71    close(fd);
72#elif OS(WINDOWS)
73    HCRYPTPROV hCryptProv = 0;
74    if (!CryptAcquireContext(&hCryptProv, 0, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
75        CRASH();
76    if (!CryptGenRandom(hCryptProv, length, buffer))
77        CRASH();
78    CryptReleaseContext(hCryptProv, 0);
79#else
80    #error "This configuration doesn't have a strong source of randomness."
81    // WARNING: When adding new sources of OS randomness, the randomness must
82    //          be of cryptographic quality!
83#endif
84}
85#endif
86
87}
88