crypto/dist/heimdal/lib/hcrypto/rand-timer.c

   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 #ifdef HAVE_CONFIG_H
  35 #include <config.h>
  36 #endif
  37
  38 __RCSID("$Heimdal$"
  39         "$NetBSD$");
  40
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <rand.h>
  44
  45 #include <roken.h>
  46
  47 #include "randi.h"
  48
  49 #ifndef WIN32 /* don't bother with this on windows */
  50
  51 static volatile int counter;
  52 static volatile unsigned char *gdata; /* Global data */
  53 static volatile int igdata;     /* Index into global data */
  54 static int gsize;
  55
  56 static
  57 RETSIGTYPE
  58 sigALRM(int sig)
  59 {
  60     if (igdata < gsize)
  61         gdata[igdata++] ^= counter & 0xff;
  62
  63 #ifndef HAVE_SIGACTION
  64     signal(SIGALRM, sigALRM); /* Reinstall SysV signal handler */
  65 #endif
  66     SIGRETURN(0);
  67 }
  68
  69 #ifndef HAVE_SETITIMER
  70 static void
  71 pacemaker(struct timeval *tv)
  72 {
  73     fd_set fds;
  74     pid_t pid;
  75     pid = getppid();
  76     while(1){
  77         FD_ZERO(&fds);
  78         FD_SET(0, &fds);
  79         select(1, &fds, NULL, NULL, tv);
  80         kill(pid, SIGALRM);
  81     }
  82 }
  83 #endif
  84
  85 #ifdef HAVE_SIGACTION
  86 /* XXX ugly hack, should perhaps use function from roken */
  87 static RETSIGTYPE
  88 (*fake_signal(int sig, RETSIGTYPE (*f)(int)))(int)
  89 {
  90     struct sigaction sa, osa;
  91     sa.sa_handler = f;
  92     sa.sa_flags = 0;
  93     sigemptyset(&sa.sa_mask);
  94     sigaction(sig, &sa, &osa);
  95     return osa.sa_handler;
  96 }
  97 #define signal(S, F) fake_signal((S), (F))
  98 #endif
  99
 100 #endif /* WIN32*/
 101
 102 /*
 103  *
 104  */
 105
 106 static void
 107 timer_seed(const void *indata, int size)
 108 {
 109 }
 110
 111 static int
 112 timer_bytes(unsigned char *outdata, int size)
 113 {
 114 #ifdef WIN32
 115     return 0;
 116 #else /* WIN32 */
 117     struct itimerval tv, otv;
 118     RETSIGTYPE (*osa)(int);
 119     int i, j;
 120 #ifndef HAVE_SETITIMER
 121     RETSIGTYPE (*ochld)(int);
 122     pid_t pid;
 123 #endif
 124
 125     gdata = outdata;
 126     gsize = size;
 127     igdata = 0;
 128
 129     osa = signal(SIGALRM, sigALRM);
 130
 131     /* Start timer */
 132     tv.it_value.tv_sec = 0;
 133     tv.it_value.tv_usec = 10 * 1000; /* 10 ms */
 134     tv.it_interval = tv.it_value;
 135 #ifdef HAVE_SETITIMER
 136     setitimer(ITIMER_REAL, &tv, &otv);
 137 #else
 138     ochld = signal(SIGCHLD, SIG_IGN);
 139     pid = fork();
 140     if(pid == -1){
 141         signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL);
 142         des_not_rand_data(data, size);
 143         return;
 144     }
 145     if(pid == 0)
 146         pacemaker(&tv.it_interval);
 147 #endif
 148
 149     for(i = 0; i < 4; i++) {
 150         for (igdata = 0; igdata < size;) /* igdata++ in sigALRM */
 151             counter++;
 152         for (j = 0; j < size; j++) /* Only use 2 bits each lap */
 153             gdata[j] = (gdata[j]>>2) | (gdata[j]<<6);
 154     }
 155 #ifdef HAVE_SETITIMER
 156     setitimer(ITIMER_REAL, &otv, 0);
 157 #else
 158     kill(pid, SIGKILL);
 159     while(waitpid(pid, NULL, 0) != pid);
 160     signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL);
 161 #endif
 162     signal(SIGALRM, osa != SIG_ERR ? osa : SIG_DFL);
 163
 164     return 1;
 165 #endif
 166 }
 167
 168 static void
 169 timer_cleanup(void)
 170 {
 171 }
 172
 173 static void
 174 timer_add(const void *indata, int size, double entropi)
 175 {
 176 }
 177
 178 static int
 179 timer_pseudorand(unsigned char *outdata, int size)
 180 {
 181     return timer_bytes(outdata, size);
 182 }
 183
 184 static int
 185 timer_status(void)
 186 {
 187 #ifdef WIN32
 188     return 0;
 189 #else
 190     return 1;
 191 #endif
 192 }
 193
 194 const RAND_METHOD hc_rand_timer_method = {
 195     timer_seed,
 196     timer_bytes,
 197     timer_cleanup,
 198     timer_add,
 199     timer_pseudorand,
 200     timer_status
 201 };
 202
 203 const RAND_METHOD *
 204 RAND_timer_method(void)
 205 {
 206     return &hc_rand_timer_method;
 207 }