OrdinaryMagician/vkdoom_m
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- Changed random seed initialization so that it uses the system's

Browse source 
cryptographically secure random number generator, if available, instead
  of the current time.
- Changed the random number generator from Lee Killough's algorithm to the
  SFMT607 variant of the Mersenne Twister.

SVN r1507 (trunk)
This commit is contained in:
Randy Heit 2009-03-27 04:49:17 +00:00
commit 7371c4a516
28 changed files with 2066 additions and 184 deletions
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41
src/win32/i_system.cpp
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@ -27,6 +27,7 @@
#include <direct.h>
#include <string.h>
#include <process.h>
#include <time.h>
#include <stdarg.h>
#include <sys/types.h>
@ -36,6 +37,7 @@
#include <windows.h>
#include <mmsystem.h>
#include <richedit.h>
#include <wincrypt.h>
#define USE_WINDOWS_DWORD
#include "hardware.h"
@ -564,7 +566,7 @@ void I_PrintStr (const char *cp)
int bpos = 0;
CHARRANGE selection;
CHARRANGE endselection;
LONG lines_before, lines_after;
LONG lines_before = 0, lines_after;
CHARFORMAT format;
if (edit != NULL)
@ -876,10 +878,39 @@ FString I_GetSteamPath()
return path;
}
long long QueryPerfCounter()
// Return a random seed, preferably one with lots of entropy.
unsigned int I_MakeRNGSeed()
{
LARGE_INTEGER counter;
unsigned int seed;
QueryPerformanceCounter(&counter);
return counter.QuadPart;
// If RtlGenRandom is available, use that to avoid increasing the
// working set by pulling in all of the crytographic API.
HMODULE advapi = GetModuleHandle("advapi32.dll");
if (advapi != NULL)
{
BOOLEAN (APIENTRY *RtlGenRandom)(void *, ULONG) =
(BOOLEAN (APIENTRY *)(void *, ULONG))GetProcAddress(advapi, "SystemFunction036");
if (RtlGenRandom != NULL)
{
if (RtlGenRandom(&seed, sizeof(seed)))
{
return seed;
}
}
}
// Use the full crytographic API to produce a seed. If that fails,
// time() is used as a fallback.
HCRYPTPROV prov;
if (!CryptAcquireContext(&prov, NULL, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
{
return (unsigned int)time(NULL);
}
if (!CryptGenRandom(prov, sizeof(seed), (BYTE *)&seed))
{
seed = (unsigned int)time(NULL);
}
CryptReleaseContext(prov, 0);
return seed;
}