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/*
* libjingle
* Copyright 2004--2005, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "talk/base/helpers.h"
#include "talk/base/time.h"
#include <cstdlib>
#include <cassert>
// TODO: Change this implementation to use OpenSSL's RAND_bytes. That will
// give cryptographically random values on all platforms.
#ifdef WIN32
#include <time.h>
#include <windows.h>
#endif
namespace cricket {
static long g_seed = 1L;
int GetRandom() {
return ((g_seed = g_seed * 214013L + 2531011L) >> 16) & 0x7fff;
}
static bool s_initrandom;
long GetRandomSeed() {
return g_seed;
}
void SetRandomSeed(unsigned long seed)
{
s_initrandom = true;
g_seed = (long)seed;
}
void InitRandom(const char *client_unique, size_t len) {
// Hash this string - unique per client
uint32 hash = 0;
if (client_unique != NULL) {
for (int i = 0; i < (int)len; i++)
hash = ((hash << 2) + hash) + client_unique[i];
}
// Now initialize the seed against a high resolution
// counter
unsigned long seed = GetRandomSeed();
#ifdef WIN32
bool success = false;
HCRYPTPROV hProv = NULL;
if (CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
success = (FALSE != CryptGenRandom(hProv,
sizeof(seed),
reinterpret_cast<BYTE*>(&seed)));
CryptReleaseContext(hProv, 0);
}
if (!success) {
LARGE_INTEGER big;
QueryPerformanceCounter(&big);
seed = big.LowPart;
}
#else
seed = talk_base::Time();
#endif
SetRandomSeed(seed ^ hash);
}
const char BASE64[64] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};
// Generates a random string of the given length. We generate base64 values so
// that they will be printable, though that's not necessary.
std::string CreateRandomString(int len) {
// Random number generator should of been initialized!
assert(s_initrandom);
if (!s_initrandom)
InitRandom(0, 0);
std::string str;
for (int i = 0; i < len; i++)
#if defined(_MSC_VER) && _MSC_VER < 1300
str.insert(str.end(), BASE64[GetRandom() & 63]);
#else
str.push_back(BASE64[GetRandom() & 63]);
#endif
return str;
}
uint32 CreateRandomId() {
uint8 b1 = (uint8)(GetRandom() & 255);
uint8 b2 = (uint8)(GetRandom() & 255);
uint8 b3 = (uint8)(GetRandom() & 255);
uint8 b4 = (uint8)(GetRandom() & 255);
return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24);
}
bool IsBase64Char(char ch) {
return (('A' <= ch) && (ch <= 'Z')) ||
(('a' <= ch) && (ch <= 'z')) ||
(('0' <= ch) && (ch <= '9')) ||
(ch == '+') || (ch == '/');
}
bool IsBase64Encoded(const std::string& str) {
for (size_t i = 0; i < str.size(); ++i) {
if (!IsBase64Char(str.at(i)))
return false;
}
return true;
}
} // namespace cricket
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