michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "secrng.h"
michael@0: 
michael@0: #ifdef XP_WIN
michael@0: #include <windows.h>
michael@0: #include <time.h>
michael@0: 
michael@0: static BOOL
michael@0: CurrentClockTickTime(LPDWORD lpdwHigh, LPDWORD lpdwLow)
michael@0: {
michael@0:     LARGE_INTEGER   liCount;
michael@0: 
michael@0:     if (!QueryPerformanceCounter(&liCount))
michael@0:         return FALSE;
michael@0: 
michael@0:     *lpdwHigh = liCount.u.HighPart;
michael@0:     *lpdwLow = liCount.u.LowPart;
michael@0:     return TRUE;
michael@0: }
michael@0: 
michael@0: size_t RNG_GetNoise(void *buf, size_t maxbuf)
michael@0: {
michael@0:     DWORD   dwHigh, dwLow, dwVal;
michael@0:     int     n = 0;
michael@0:     int     nBytes;
michael@0:     time_t  sTime;
michael@0: 
michael@0:     if (maxbuf <= 0)
michael@0:         return 0;
michael@0: 
michael@0:     CurrentClockTickTime(&dwHigh, &dwLow);
michael@0: 
michael@0:     // get the maximally changing bits first
michael@0:     nBytes = sizeof(dwLow) > maxbuf ? maxbuf : sizeof(dwLow);
michael@0:     memcpy((char *)buf, &dwLow, nBytes);
michael@0:     n += nBytes;
michael@0:     maxbuf -= nBytes;
michael@0: 
michael@0:     if (maxbuf <= 0)
michael@0:         return n;
michael@0: 
michael@0:     nBytes = sizeof(dwHigh) > maxbuf ? maxbuf : sizeof(dwHigh);
michael@0:     memcpy(((char *)buf) + n, &dwHigh, nBytes);
michael@0:     n += nBytes;
michael@0:     maxbuf -= nBytes;
michael@0: 
michael@0:     if (maxbuf <= 0)
michael@0:         return n;
michael@0: 
michael@0:     // get the number of milliseconds that have elapsed since Windows started
michael@0:     dwVal = GetTickCount();
michael@0: 
michael@0:     nBytes = sizeof(dwVal) > maxbuf ? maxbuf : sizeof(dwVal);
michael@0:     memcpy(((char *)buf) + n, &dwVal, nBytes);
michael@0:     n += nBytes;
michael@0:     maxbuf -= nBytes;
michael@0: 
michael@0:     if (maxbuf <= 0)
michael@0:         return n;
michael@0: 
michael@0:     // get the time in seconds since midnight Jan 1, 1970
michael@0:     time(&sTime);
michael@0:     nBytes = sizeof(sTime) > maxbuf ? maxbuf : sizeof(sTime);
michael@0:     memcpy(((char *)buf) + n, &sTime, nBytes);
michael@0:     n += nBytes;
michael@0: 
michael@0:     return n;
michael@0: }
michael@0: 
michael@0: void RNG_SystemInfoForRNG(void)
michael@0: {
michael@0:     DWORD           dwVal;
michael@0:     char            buffer[256];
michael@0:     int             nBytes;
michael@0:     MEMORYSTATUS    sMem;
michael@0:     HANDLE          hVal;
michael@0:     DWORD           dwSerialNum;
michael@0:     DWORD           dwComponentLen;
michael@0:     DWORD           dwSysFlags;
michael@0:     char            volName[128];
michael@0:     DWORD           dwSectors, dwBytes, dwFreeClusters, dwNumClusters;
michael@0: 
michael@0:     nBytes = RNG_GetNoise(buffer, 20);  // get up to 20 bytes
michael@0:     RNG_RandomUpdate(buffer, nBytes);
michael@0: 
michael@0:     sMem.dwLength = sizeof(sMem);
michael@0:     GlobalMemoryStatus(&sMem);                // assorted memory stats
michael@0:     RNG_RandomUpdate(&sMem, sizeof(sMem));
michael@0: 
michael@0:     dwVal = GetLogicalDrives();
michael@0:     RNG_RandomUpdate(&dwVal, sizeof(dwVal));  // bitfields in bits 0-25
michael@0: 
michael@0:     dwVal = sizeof(buffer);
michael@0:     if (GetComputerName(buffer, &dwVal))
michael@0:         RNG_RandomUpdate(buffer, dwVal);
michael@0: 
michael@0:     hVal = GetCurrentProcess();               // 4 or 8 byte pseudo handle (a
michael@0:                                               // constant!) of current process
michael@0:     RNG_RandomUpdate(&hVal, sizeof(hVal));
michael@0: 
michael@0:     dwVal = GetCurrentProcessId();            // process ID (4 bytes)
michael@0:     RNG_RandomUpdate(&dwVal, sizeof(dwVal));
michael@0: 
michael@0:     dwVal = GetCurrentThreadId();             // thread ID (4 bytes)
michael@0:     RNG_RandomUpdate(&dwVal, sizeof(dwVal));
michael@0: 
michael@0:     volName[0] = '\0';
michael@0:     buffer[0] = '\0';
michael@0:     GetVolumeInformation(NULL,
michael@0:                          volName,
michael@0:                          sizeof(volName),
michael@0:                          &dwSerialNum,
michael@0:                          &dwComponentLen,
michael@0:                          &dwSysFlags,
michael@0:                          buffer,
michael@0:                          sizeof(buffer));
michael@0: 
michael@0:     RNG_RandomUpdate(volName,         strlen(volName));
michael@0:     RNG_RandomUpdate(&dwSerialNum,    sizeof(dwSerialNum));
michael@0:     RNG_RandomUpdate(&dwComponentLen, sizeof(dwComponentLen));
michael@0:     RNG_RandomUpdate(&dwSysFlags,     sizeof(dwSysFlags));
michael@0:     RNG_RandomUpdate(buffer,          strlen(buffer));
michael@0: 
michael@0:     if (GetDiskFreeSpace(NULL, &dwSectors, &dwBytes, &dwFreeClusters, 
michael@0:                          &dwNumClusters)) {
michael@0:         RNG_RandomUpdate(&dwSectors,      sizeof(dwSectors));
michael@0:         RNG_RandomUpdate(&dwBytes,        sizeof(dwBytes));
michael@0:         RNG_RandomUpdate(&dwFreeClusters, sizeof(dwFreeClusters));
michael@0:         RNG_RandomUpdate(&dwNumClusters,  sizeof(dwNumClusters));
michael@0:     }
michael@0: 
michael@0:     nBytes = RNG_GetNoise(buffer, 20);  // get up to 20 bytes
michael@0:     RNG_RandomUpdate(buffer, nBytes);
michael@0: }
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * The RtlGenRandom function is declared in <ntsecapi.h>, but the
michael@0:  * declaration is missing a calling convention specifier. So we
michael@0:  * declare it manually here.
michael@0:  */
michael@0: #define RtlGenRandom SystemFunction036
michael@0: DECLSPEC_IMPORT BOOLEAN WINAPI RtlGenRandom(
michael@0:     PVOID RandomBuffer,
michael@0:     ULONG RandomBufferLength);
michael@0: 
michael@0: size_t RNG_SystemRNG(void *dest, size_t maxLen)
michael@0: {
michael@0:     size_t bytes = 0;
michael@0: 
michael@0:     if (RtlGenRandom(dest, maxLen)) {
michael@0: 	bytes = maxLen;
michael@0:     }
michael@0:     return bytes;
michael@0: }
michael@0: #endif  /* is XP_WIN */