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

   1 /*      $NetBSD: rand-timer.c,v 1.1.1.1 2011/04/13 18:14:50 elric Exp $ */
   2
   3 /*
   4  * Copyright (c) 1995, 1996, 1997, 1999, 2007 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <config.h>
  37
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <rand.h>
  41
  42 #include <krb5/roken.h>
  43
  44 #include "randi.h"
  45
  46 #ifndef WIN32 /* don't bother with this on windows */
  47
  48 static volatile int counter;
  49 static volatile unsigned char *gdata; /* Global data */
  50 static volatile int igdata;     /* Index into global data */
  51 static int gsize;
  52
  53 static
  54 RETSIGTYPE
  55 sigALRM(int sig)
  56 {
  57     if (igdata < gsize)
  58         gdata[igdata++] ^= counter & 0xff;
  59
  60 #ifndef HAVE_SIGACTION
  61     signal(SIGALRM, sigALRM); /* Reinstall SysV signal handler */
  62 #endif
  63     SIGRETURN(0);
  64 }
  65
  66 #ifndef HAVE_SETITIMER
  67 static void
  68 pacemaker(struct timeval *tv)
  69 {
  70     fd_set fds;
  71     pid_t pid;
  72     pid = getppid();
  73     while(1){
  74         FD_ZERO(&fds);
  75         FD_SET(0, &fds);
  76         select(1, &fds, NULL, NULL, tv);
  77         kill(pid, SIGALRM);
  78     }
  79 }
  80 #endif
  81
  82 #ifdef HAVE_SIGACTION
  83 /* XXX ugly hack, should perhaps use function from roken */
  84 static RETSIGTYPE
  85 (*fake_signal(int sig, RETSIGTYPE (*f)(int)))(int)
  86 {
  87     struct sigaction sa, osa;
  88     sa.sa_handler = f;
  89     sa.sa_flags = 0;
  90     sigemptyset(&sa.sa_mask);
  91     sigaction(sig, &sa, &osa);
  92     return osa.sa_handler;
  93 }
  94 #define signal(S, F) fake_signal((S), (F))
  95 #endif
  96
  97 #endif /* WIN32*/
  98
  99 /*
 100  *
 101  */
 102
 103 static void
 104 timer_seed(const void *indata, int size)
 105 {
 106 }
 107
 108 static int
 109 timer_bytes(unsigned char *outdata, int size)
 110 {
 111 #ifdef WIN32
 112     return 0;
 113 #else /* WIN32 */
 114     struct itimerval tv, otv;
 115     RETSIGTYPE (*osa)(int);
 116     int i, j;
 117 #ifndef HAVE_SETITIMER
 118     RETSIGTYPE (*ochld)(int);
 119     pid_t pid;
 120 #endif
 121
 122     gdata = outdata;
 123     gsize = size;
 124     igdata = 0;
 125
 126     osa = signal(SIGALRM, sigALRM);
 127
 128     /* Start timer */
 129     tv.it_value.tv_sec = 0;
 130     tv.it_value.tv_usec = 10 * 1000; /* 10 ms */
 131     tv.it_interval = tv.it_value;
 132 #ifdef HAVE_SETITIMER
 133     setitimer(ITIMER_REAL, &tv, &otv);
 134 #else
 135     ochld = signal(SIGCHLD, SIG_IGN);
 136     pid = fork();
 137     if(pid == -1){
 138         signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL);
 139         des_not_rand_data(data, size);
 140         return;
 141     }
 142     if(pid == 0)
 143         pacemaker(&tv.it_interval);
 144 #endif
 145
 146     for(i = 0; i < 4; i++) {
 147         for (igdata = 0; igdata < size;) /* igdata++ in sigALRM */
 148             counter++;
 149         for (j = 0; j < size; j++) /* Only use 2 bits each lap */
 150             gdata[j] = (gdata[j]>>2) | (gdata[j]<<6);
 151     }
 152 #ifdef HAVE_SETITIMER
 153     setitimer(ITIMER_REAL, &otv, 0);
 154 #else
 155     kill(pid, SIGKILL);
 156     while(waitpid(pid, NULL, 0) != pid);
 157     signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL);
 158 #endif
 159     signal(SIGALRM, osa != SIG_ERR ? osa : SIG_DFL);
 160
 161     return 1;
 162 #endif
 163 }
 164
 165 static void
 166 timer_cleanup(void)
 167 {
 168 }
 169
 170 static void
 171 timer_add(const void *indata, int size, double entropi)
 172 {
 173 }
 174
 175 static int
 176 timer_pseudorand(unsigned char *outdata, int size)
 177 {
 178     return timer_bytes(outdata, size);
 179 }
 180
 181 static int
 182 timer_status(void)
 183 {
 184 #ifdef WIN32
 185     return 0;
 186 #else
 187     return 1;
 188 #endif
 189 }
 190
 191 const RAND_METHOD hc_rand_timer_method = {
 192     timer_seed,
 193     timer_bytes,
 194     timer_cleanup,
 195     timer_add,
 196     timer_pseudorand,
 197     timer_status
 198 };
 199
 200 const RAND_METHOD *
 201 RAND_timer_method(void)
 202 {
 203     return &hc_rand_timer_method;
 204 }