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
|
/* $Id: rndseed.C,v 1.14 2003/11/05 21:36:57 dm Exp $ */
/*
*
* Copyright (C) 1998 David Mazieres (dm@uun.org)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2, or (at
* your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*
*/
#include "crypt.h"
prng rnd;
sha1oracle rnd_input (64, 0, 8);
enum { seedsize = 48 };
const int mapsize = sysconf (_SC_PAGESIZE);
static void *seed;
static bool initialized;
static u_int64_t nupdates;
EXITFN(saveseed);
static void
saveseed ()
{
if (seed)
random_update ();
}
void
random_update ()
{
if (seed)
rnd_input.update (seed, seedsize);
getclocknoise (&rnd_input);
rnd.seed_oracle (&rnd_input);
if (seed)
rnd.getbytes (seed, seedsize);
nupdates++;
}
static void
random_stir ()
{
getsysnoise (&rnd_input, wrap (random_update));
}
static void
random_timer ()
{
random_stir ();
timecb (time (NULL) + 1800 + rnd.getword () % 1800, wrap (random_timer));
}
static u_int32_t
random_word ()
{
return rnd.getword ();
}
void
random_start ()
{
if (!initialized) {
initialized = true;
random_update ();
arandom_fn = random_word;
random_timer ();
}
}
void
random_init ()
{
if (initialized)
random_update ();
else {
random_start ();
while (!nupdates)
acheck ();
}
}
void
random_set_seedfile (str path)
{
if (!path) {
if (seed) {
munmap (reinterpret_cast<char *> (seed), mapsize);
seed = NULL;
}
return;
}
if (path[0] == '~' && path[1] == '/') {
const char *home = getenv ("HOME");
if (!home) {
warn ("$HOME not set in environment\n");
return;
}
path = strbuf () << home << (path.cstr () + 1);
}
int fd = open (path, O_CREAT|O_RDWR, 0600);
if (fd < 0) {
warn ("%s: %m\n", path.cstr ());
return;
}
struct stat sb;
char c;
if (read (fd, &c, 1) < 0 || fstat (fd, &sb) < 0
|| lseek (fd, mapsize - 1, SEEK_SET) == -1
|| write (fd, "", 1) < 0) {
/* The read call avoids a segfault on NFS 2. Specifically, if we
* are root and the random_seed file is over NFS 2, the open will
* succeed even though read returns EACCES. If we map the file
* when we can't read it--bingo, segfault. (In fact, on some OSes
* it also seems to cause a kernel panic when you examine the
* mmapped memory from the debugger.) */
close (fd);
warn ("%s: %m\n", path.cstr ());
return;
}
if ((sb.st_mode & 07777) != 0600)
warn ("%s: mode 0%o should be 0600\n", path.cstr (), sb.st_mode & 07777);
if (seed)
munmap (reinterpret_cast<char *> (seed), mapsize);
seed = mmap (NULL, (size_t) mapsize, PROT_READ|PROT_WRITE,
MAP_FILE|MAP_SHARED, fd, 0);
if (seed == reinterpret_cast<void *> (MAP_FAILED)) {
warn ("mmap: %s: %m\n", path.cstr ());
seed = NULL;
}
else
rnd_input.update (seed, seedsize);
close (fd);
}
void
random_init_file (str path)
{
random_set_seedfile (path);
random_init ();
}
u_int32_t
random_getword ()
{
if (!initialized)
random_init ();
return rnd.getword ();
}
|
