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
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
/* -*- Mode: C; c-file-style: "stroustrup" -*- */
#include <stdio.h>
#include <limits.h>
#include <string.h>
#include <sys/time.h>
#include "random.h"
int initialized = 0;
/* on machines that have /dev/urandom -- use it */
#if defined( __linux__ ) || defined( __FreeBSD__ ) || defined( __MACH__ ) || \
defined( __OpenBSD__ ) || defined( DEV_URANDOM )
#define URANDOM_FILE "/dev/urandom"
FILE* urandom = NULL;
int random_init( void )
{
int res = (urandom = fopen( URANDOM_FILE, "r" )) != NULL;
if ( res ) { initialized = 1; }
return res;
}
int random_getbytes( void* data, size_t len )
{
if ( !initialized && !random_init() ) { return 0; }
return fread( data, len, 1, urandom );
}
int random_final( void )
{
int res = 0;
if ( urandom ) { res = (fclose( urandom ) == 0); }
return res;
}
#else
/* if no /dev/urandom fall back to a crappy rng who's only
* entropy source is your high resolution timer
*/
/* on windows we are ok as we can use CAPI, but use CAPI combined with
the below just to be sure! */
/* WARNING: on platforms other than windows this is not of
* cryptographic quality
*/
#include <stdlib.h>
#if defined( unix ) || defined( VMS )
#include <unistd.h>
#include <sys/time.h>
#elif defined( WIN32 )
#include <process.h>
#include <windows.h>
#include <wincrypt.h>
#include <sys/time.h>
#else
#include <time.h>
#endif
#include <time.h>
#if defined( OPENSSL )
#include <openssl/sha.h>
#define SHA1_ctx SHA_CTX
#define SHA1_Final( x, digest ) SHA1_Final( digest, x )
#define SHA1_DIGEST_BYTES SHA_DIGEST_LENGTH
#else
#include "sha1.h"
#endif
#if defined( WIN32 )
#define pid_t int
typedef BOOL (WINAPI *CRYPTACQUIRECONTEXT)(HCRYPTPROV *, LPCTSTR, LPCTSTR,
DWORD, DWORD);
typedef BOOL (WINAPI *CRYPTGENRANDOM)(HCRYPTPROV, DWORD, BYTE *);
typedef BOOL (WINAPI *CRYPTRELEASECONTEXT)(HCRYPTPROV, DWORD);
HCRYPTPROV hProvider = 0;
CRYPTRELEASECONTEXT release = 0;
CRYPTGENRANDOM gen = 0;
#endif
byte state[ SHA1_DIGEST_BYTES ];
byte output[ SHA1_DIGEST_BYTES ];
long counter = 0;
/* output = SHA1( input || time || pid || counter++ ) */
static void random_stir( const byte input[SHA1_DIGEST_BYTES],
byte output[SHA1_DIGEST_BYTES] )
{
SHA1_ctx sha1;
#if defined(__unix__) || defined(WIN32)
pid_t pid = getpid();
#else
unsigned long pid = rand();
#endif
#if defined(__unix__)
struct timeval tv = {};
struct timezone tz = {};
#endif
#if defined(WIN32)
SYSTEMTIME tw;
BYTE buf[64];
#endif
clock_t t = clock();
time_t t2 = time(0);
SHA1_Init( &sha1 );
#if defined(__unix__)
gettimeofday(&tv,&tz);
SHA1_Update( &sha1, &tv, sizeof( tv ) );
SHA1_Update( &sha1, &tz, sizeof( tz ) );
#endif
#if defined(WIN32)
GetSystemTime(&tw);
SHA1_Update( &sha1, &tw, sizeof( tw ) );
if ( gen ) {
if (gen(hProvider, sizeof(buf), buf)) {
SHA1_Update( &sha1, buf, sizeof(buf) );
}
}
#endif
SHA1_Update( &sha1, input, SHA1_DIGEST_BYTES );
SHA1_Update( &sha1, &t, sizeof( clock_t ) );
SHA1_Update( &sha1, &t2, sizeof( time_t ) );
SHA1_Update( &sha1, &pid, sizeof( pid ) );
SHA1_Update( &sha1, &counter, sizeof( long ) );
SHA1_Final( &sha1, output );
counter++;
}
int random_init( void )
{
#if defined(WIN32)
HMODULE advapi = 0;
CRYPTACQUIRECONTEXT acquire = 0;
#endif
#if defined(WIN32)
advapi = LoadLibrary(TEXT("ADVAPI32.DLL"));
if (advapi) {
acquire = (CRYPTACQUIRECONTEXT)
GetProcAddress(advapi, TEXT("CryptAcquireContextA"));
gen = (CRYPTGENRANDOM)
GetProcAddress(advapi, TEXT("CryptGenRandom"));
release = (CRYPTRELEASECONTEXT)
GetProcAddress(advapi, TEXT("CryptReleaseContext"));
}
if ( acquire && gen ) {
if (!acquire(&hProvider, 0, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
gen = NULL;
}
}
#endif
srand(clock());
random_stir( state, state );
initialized = 1;
return 1;
}
int random_final( void )
{
#if defined(WIN32)
if ( hProvider && release ) { release(hProvider,0); }
#endif
return 1;
}
#define CHUNK_LEN (SHA1_DIGEST_BYTES)
int random_getbytes( void* rnd, size_t len )
{
byte* rndp = (byte*)rnd;
int use = 0;
if ( !initialized && !random_init() ) { return 0; }
random_stir( state, state ); /* mix in the time, pid */
for ( ; len > 0; len -= use, rndp += CHUNK_LEN ) {
random_stir( state, output );
use = len > CHUNK_LEN ? CHUNK_LEN : len;
memcpy( rndp, output, use );
}
return 1;
}
#endif
static int count_bits( long val )
{
int count = 0 ;
for ( count = 0; val; val >>= 1, count++ ) { }
return count;
}
int random_rectangular( long top, long* resp )
{
long mask = 0 ;
int neg = 1;
long res = 0 ;
if ( top < 0 ) { neg = -1; top = -top; }
mask = ~( LONG_MAX << count_bits( top ) );
do {
if ( !random_getbytes( &res, sizeof( long ) ) ) { return 0; }
res &= mask;
} while ( res > top );
*resp = res * neg;
return 1;
}
|
