1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "secrng.h"
#ifdef XP_WIN
#include <windows.h>
#include <time.h>
static BOOL
CurrentClockTickTime(LPDWORD lpdwHigh, LPDWORD lpdwLow)
{
LARGE_INTEGER liCount;
if (!QueryPerformanceCounter(&liCount))
return FALSE;
*lpdwHigh = liCount.u.HighPart;
*lpdwLow = liCount.u.LowPart;
return TRUE;
}
size_t
RNG_GetNoise(void *buf, size_t maxbuf)
{
DWORD dwHigh, dwLow, dwVal;
int n = 0;
int nBytes;
time_t sTime;
if (maxbuf <= 0)
return 0;
CurrentClockTickTime(&dwHigh, &dwLow);
// get the maximally changing bits first
nBytes = sizeof(dwLow) > maxbuf ? maxbuf : sizeof(dwLow);
memcpy((char *)buf, &dwLow, nBytes);
n += nBytes;
maxbuf -= nBytes;
if (maxbuf <= 0)
return n;
nBytes = sizeof(dwHigh) > maxbuf ? maxbuf : sizeof(dwHigh);
memcpy(((char *)buf) + n, &dwHigh, nBytes);
n += nBytes;
maxbuf -= nBytes;
if (maxbuf <= 0)
return n;
// get the number of milliseconds that have elapsed since Windows started
dwVal = GetTickCount();
nBytes = sizeof(dwVal) > maxbuf ? maxbuf : sizeof(dwVal);
memcpy(((char *)buf) + n, &dwVal, nBytes);
n += nBytes;
maxbuf -= nBytes;
if (maxbuf <= 0)
return n;
// get the time in seconds since midnight Jan 1, 1970
time(&sTime);
nBytes = sizeof(sTime) > maxbuf ? maxbuf : sizeof(sTime);
memcpy(((char *)buf) + n, &sTime, nBytes);
n += nBytes;
return n;
}
void
RNG_SystemInfoForRNG(void)
{
DWORD dwVal;
char buffer[256];
int nBytes;
MEMORYSTATUS sMem;
HANDLE hVal;
DWORD dwSerialNum;
DWORD dwComponentLen;
DWORD dwSysFlags;
char volName[128];
DWORD dwSectors, dwBytes, dwFreeClusters, dwNumClusters;
nBytes = RNG_GetNoise(buffer, 20); // get up to 20 bytes
RNG_RandomUpdate(buffer, nBytes);
sMem.dwLength = sizeof(sMem);
GlobalMemoryStatus(&sMem); // assorted memory stats
RNG_RandomUpdate(&sMem, sizeof(sMem));
dwVal = GetLogicalDrives();
RNG_RandomUpdate(&dwVal, sizeof(dwVal)); // bitfields in bits 0-25
dwVal = sizeof(buffer);
if (GetComputerName(buffer, &dwVal))
RNG_RandomUpdate(buffer, dwVal);
hVal = GetCurrentProcess(); // 4 or 8 byte pseudo handle (a
// constant!) of current process
RNG_RandomUpdate(&hVal, sizeof(hVal));
dwVal = GetCurrentProcessId(); // process ID (4 bytes)
RNG_RandomUpdate(&dwVal, sizeof(dwVal));
dwVal = GetCurrentThreadId(); // thread ID (4 bytes)
RNG_RandomUpdate(&dwVal, sizeof(dwVal));
volName[0] = '\0';
buffer[0] = '\0';
GetVolumeInformation(NULL,
volName,
sizeof(volName),
&dwSerialNum,
&dwComponentLen,
&dwSysFlags,
buffer,
sizeof(buffer));
RNG_RandomUpdate(volName, strlen(volName));
RNG_RandomUpdate(&dwSerialNum, sizeof(dwSerialNum));
RNG_RandomUpdate(&dwComponentLen, sizeof(dwComponentLen));
RNG_RandomUpdate(&dwSysFlags, sizeof(dwSysFlags));
RNG_RandomUpdate(buffer, strlen(buffer));
if (GetDiskFreeSpace(NULL, &dwSectors, &dwBytes, &dwFreeClusters,
&dwNumClusters)) {
RNG_RandomUpdate(&dwSectors, sizeof(dwSectors));
RNG_RandomUpdate(&dwBytes, sizeof(dwBytes));
RNG_RandomUpdate(&dwFreeClusters, sizeof(dwFreeClusters));
RNG_RandomUpdate(&dwNumClusters, sizeof(dwNumClusters));
}
nBytes = RNG_GetNoise(buffer, 20); // get up to 20 bytes
RNG_RandomUpdate(buffer, nBytes);
}
/*
* The RtlGenRandom function is declared in <ntsecapi.h>, but the
* declaration is missing a calling convention specifier. So we
* declare it manually here.
*/
#define RtlGenRandom SystemFunction036
DECLSPEC_IMPORT BOOLEAN WINAPI RtlGenRandom(
PVOID RandomBuffer,
ULONG RandomBufferLength);
size_t
RNG_SystemRNG(void *dest, size_t maxLen)
{
size_t bytes = 0;
if (RtlGenRandom(dest, maxLen)) {
bytes = maxLen;
}
return bytes;
}
#endif /* is XP_WIN */
|
