1/* 2 * Copyright (c) 1995, 1996, 1997, 1999, 2007 Kungliga Tekniska H��gskolan 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 36#include <stdio.h> 37#include <stdlib.h> 38#include <rand.h> 39 40#include <roken.h> 41 42#include "randi.h" 43 44#ifndef WIN32 /* don't bother with this on windows */ 45 46static volatile int counter; 47static volatile unsigned char *gdata; /* Global data */ 48static volatile int igdata; /* Index into global data */ 49static int gsize; 50 51static 52RETSIGTYPE 53sigALRM(int sig) 54{ 55 if (igdata < gsize) 56 gdata[igdata++] ^= counter & 0xff; 57 58#ifndef HAVE_SIGACTION 59 signal(SIGALRM, sigALRM); /* Reinstall SysV signal handler */ 60#endif 61 SIGRETURN(0); 62} 63 64#ifndef HAVE_SETITIMER 65static void 66pacemaker(struct timeval *tv) 67{ 68 fd_set fds; 69 pid_t pid; 70 pid = getppid(); 71 while(1){ 72 FD_ZERO(&fds); 73 FD_SET(0, &fds); 74 select(1, &fds, NULL, NULL, tv); 75 kill(pid, SIGALRM); 76 } 77} 78#endif 79 80#ifdef HAVE_SIGACTION 81/* XXX ugly hack, should perhaps use function from roken */ 82static RETSIGTYPE 83(*fake_signal(int sig, RETSIGTYPE (*f)(int)))(int) 84{ 85 struct sigaction sa, osa; 86 sa.sa_handler = f; 87 sa.sa_flags = 0; 88 sigemptyset(&sa.sa_mask); 89 sigaction(sig, &sa, &osa); 90 return osa.sa_handler; 91} 92#define signal(S, F) fake_signal((S), (F)) 93#endif 94 95#endif /* WIN32*/ 96 97/* 98 * 99 */ 100 101static void 102timer_seed(const void *indata, int size) 103{ 104} 105 106static int 107timer_bytes(unsigned char *outdata, int size) 108{ 109#ifdef WIN32 110 return 0; 111#else /* WIN32 */ 112 struct itimerval tv, otv; 113 RETSIGTYPE (*osa)(int); 114 int i, j; 115#ifndef HAVE_SETITIMER 116 RETSIGTYPE (*ochld)(int); 117 pid_t pid; 118#endif 119 120 gdata = outdata; 121 gsize = size; 122 igdata = 0; 123 124 osa = signal(SIGALRM, sigALRM); 125 126 /* Start timer */ 127 tv.it_value.tv_sec = 0; 128 tv.it_value.tv_usec = 10 * 1000; /* 10 ms */ 129 tv.it_interval = tv.it_value; 130#ifdef HAVE_SETITIMER 131 setitimer(ITIMER_REAL, &tv, &otv); 132#else 133 ochld = signal(SIGCHLD, SIG_IGN); 134 pid = fork(); 135 if(pid == -1){ 136 signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL); 137 des_not_rand_data(data, size); 138 return; 139 } 140 if(pid == 0) 141 pacemaker(&tv.it_interval); 142#endif 143 144 for(i = 0; i < 4; i++) { 145 for (igdata = 0; igdata < size;) /* igdata++ in sigALRM */ 146 counter++; 147 for (j = 0; j < size; j++) /* Only use 2 bits each lap */ 148 gdata[j] = (gdata[j]>>2) | (gdata[j]<<6); 149 } 150#ifdef HAVE_SETITIMER 151 setitimer(ITIMER_REAL, &otv, 0); 152#else 153 kill(pid, SIGKILL); 154 while(waitpid(pid, NULL, 0) != pid); 155 signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL); 156#endif 157 signal(SIGALRM, osa != SIG_ERR ? osa : SIG_DFL); 158 159 return 1; 160#endif 161} 162 163static void 164timer_cleanup(void) 165{ 166} 167 168static void 169timer_add(const void *indata, int size, double entropi) 170{ 171} 172 173static int 174timer_pseudorand(unsigned char *outdata, int size) 175{ 176 return timer_bytes(outdata, size); 177} 178 179static int 180timer_status(void) 181{ 182#ifdef WIN32 183 return 0; 184#else 185 return 1; 186#endif 187} 188 189const RAND_METHOD hc_rand_timer_method = { 190 timer_seed, 191 timer_bytes, 192 timer_cleanup, 193 timer_add, 194 timer_pseudorand, 195 timer_status 196}; 197 198const RAND_METHOD * 199RAND_timer_method(void) 200{ 201 return &hc_rand_timer_method; 202} 203