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
46 namespace WTF {
47
48 #if USE(OS_RANDOMNESS)
cryptographicallyRandomValuesFromOS(unsigned char * buffer,size_t length)49 void 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