Line data Source code
1 : /*
2 : * Copyright (c) 1995, 1996, 1997, 1999, 2007 Kungliga Tekniska Högskolan
3 : * (Royal Institute of Technology, Stockholm, Sweden).
4 : * All rights reserved.
5 : *
6 : * Redistribution and use in source and binary forms, with or without
7 : * modification, are permitted provided that the following conditions
8 : * are met:
9 : *
10 : * 1. Redistributions of source code must retain the above copyright
11 : * notice, this list of conditions and the following disclaimer.
12 : *
13 : * 2. Redistributions in binary form must reproduce the above copyright
14 : * notice, this list of conditions and the following disclaimer in the
15 : * documentation and/or other materials provided with the distribution.
16 : *
17 : * 3. Neither the name of the Institute nor the names of its contributors
18 : * may be used to endorse or promote products derived from this software
19 : * without specific prior written permission.
20 : *
21 : * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 : * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 : * SUCH DAMAGE.
32 : */
33 :
34 : #include <config.h>
35 : #include <roken.h>
36 :
37 : #include <rand.h>
38 :
39 : #include "randi.h"
40 :
41 : #ifndef WIN32 /* don't bother with this on windows */
42 :
43 : static volatile int counter;
44 : static volatile unsigned char *gdata; /* Global data */
45 : static volatile int igdata; /* Index into global data */
46 : static int gsize;
47 :
48 : static
49 : RETSIGTYPE
50 0 : sigALRM(int sig)
51 : {
52 0 : if (igdata < gsize)
53 0 : gdata[igdata++] ^= counter & 0xff;
54 :
55 : #ifndef HAVE_SIGACTION
56 : signal(SIGALRM, sigALRM); /* Reinstall SysV signal handler */
57 : #endif
58 0 : SIGRETURN(0);
59 : }
60 :
61 : #ifndef HAVE_SETITIMER
62 : static void
63 : pacemaker(struct timeval *tv)
64 : {
65 : fd_set fds;
66 : pid_t pid;
67 : pid = getppid();
68 : while(1){
69 : FD_ZERO(&fds);
70 : FD_SET(0, &fds);
71 : select(1, &fds, NULL, NULL, tv);
72 : kill(pid, SIGALRM);
73 : }
74 : }
75 : #endif
76 :
77 : #ifdef HAVE_SIGACTION
78 : /* XXX ugly hack, should perhaps use function from roken */
79 : static RETSIGTYPE
80 0 : (*fake_signal(int sig, RETSIGTYPE (*f)(int)))(int)
81 : {
82 0 : struct sigaction sa, osa;
83 0 : sa.sa_handler = f;
84 0 : sa.sa_flags = 0;
85 0 : sigemptyset(&sa.sa_mask);
86 0 : sigaction(sig, &sa, &osa);
87 0 : return osa.sa_handler;
88 : }
89 : #define signal(S, F) fake_signal((S), (F))
90 : #endif
91 :
92 : #endif /* WIN32*/
93 :
94 : /*
95 : *
96 : */
97 :
98 : static void
99 0 : timer_seed(const void *indata, int size)
100 : {
101 0 : }
102 :
103 : static int
104 0 : timer_bytes(unsigned char *outdata, int size)
105 : {
106 : #ifdef WIN32
107 : return 0;
108 : #else /* WIN32 */
109 0 : struct itimerval tv, otv;
110 0 : RETSIGTYPE (*osa)(int);
111 0 : int i, j;
112 : #ifndef HAVE_SETITIMER
113 : RETSIGTYPE (*ochld)(int);
114 : pid_t pid;
115 : #endif
116 :
117 0 : gdata = outdata;
118 0 : gsize = size;
119 0 : igdata = 0;
120 :
121 0 : osa = signal(SIGALRM, sigALRM);
122 :
123 : /* Start timer */
124 0 : tv.it_value.tv_sec = 0;
125 0 : tv.it_value.tv_usec = 10 * 1000; /* 10 ms */
126 0 : tv.it_interval = tv.it_value;
127 : #ifdef HAVE_SETITIMER
128 0 : setitimer(ITIMER_REAL, &tv, &otv);
129 : #else
130 : ochld = signal(SIGCHLD, SIG_IGN);
131 : pid = fork();
132 : if(pid == -1){
133 : signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL);
134 : des_not_rand_data(data, size);
135 : return;
136 : }
137 : if(pid == 0)
138 : pacemaker(&tv.it_interval);
139 : #endif
140 :
141 0 : for(i = 0; i < 4; i++) {
142 0 : for (igdata = 0; igdata < size;) /* igdata++ in sigALRM */
143 0 : counter++;
144 0 : for (j = 0; j < size; j++) /* Only use 2 bits each lap */
145 0 : gdata[j] = (gdata[j]>>2) | (gdata[j]<<6);
146 : }
147 : #ifdef HAVE_SETITIMER
148 0 : setitimer(ITIMER_REAL, &otv, 0);
149 : #else
150 : kill(pid, SIGKILL);
151 : while(waitpid(pid, NULL, 0) != pid);
152 : signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL);
153 : #endif
154 0 : signal(SIGALRM, osa != SIG_ERR ? osa : SIG_DFL);
155 :
156 0 : return 1;
157 : #endif
158 : }
159 :
160 : static void
161 0 : timer_cleanup(void)
162 : {
163 0 : }
164 :
165 : static void
166 0 : timer_add(const void *indata, int size, double entropi)
167 : {
168 0 : }
169 :
170 : static int
171 0 : timer_pseudorand(unsigned char *outdata, int size)
172 : {
173 0 : return timer_bytes(outdata, size);
174 : }
175 :
176 : static int
177 0 : timer_status(void)
178 : {
179 : #ifdef WIN32
180 : return 0;
181 : #else
182 0 : return 1;
183 : #endif
184 : }
185 :
186 : #if defined(__GNUC__) || (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901)
187 : const RAND_METHOD hc_rand_timer_method = {
188 : .seed = timer_seed,
189 : .bytes = timer_bytes,
190 : .cleanup = timer_cleanup,
191 : .add = timer_add,
192 : .pseudorand = timer_pseudorand,
193 : .status = timer_status
194 : };
195 : #else
196 : const RAND_METHOD hc_rand_timer_method = {
197 : timer_seed,
198 : timer_bytes,
199 : timer_cleanup,
200 : timer_add,
201 : timer_pseudorand,
202 : timer_status
203 : };
204 : #endif
205 :
206 : const RAND_METHOD *
207 0 : RAND_timer_method(void)
208 : {
209 0 : return &hc_rand_timer_method;
210 : }
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