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 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(UNIX) 33#include <fcntl.h> 34#include <unistd.h> 35#endif 36 37#if OS(WINDOWS) 38#include <windows.h> 39#include <wincrypt.h> // windows.h must be included before wincrypt.h. 40#endif 41 42namespace WTF { 43 44void cryptographicallyRandomValuesFromOS(unsigned char* buffer, size_t length) 45{ 46#if OS(UNIX) 47 int fd = open("/dev/urandom", O_RDONLY, 0); 48 if (fd < 0) 49 CRASH(); // We need /dev/urandom for this API to work... 50 51 if (read(fd, buffer, length) != static_cast<ssize_t>(length)) 52 CRASH(); 53 54 close(fd); 55#elif OS(WINDOWS) 56 HCRYPTPROV hCryptProv = 0; 57 if (!CryptAcquireContext(&hCryptProv, 0, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) 58 CRASH(); 59 if (!CryptGenRandom(hCryptProv, length, buffer)) 60 CRASH(); 61 CryptReleaseContext(hCryptProv, 0); 62#else 63 #error "This configuration doesn't have a strong source of randomness." 64 // WARNING: When adding new sources of OS randomness, the randomness must 65 // be of cryptographic quality! 66#endif 67} 68 69} 70