/* * Copyright (c) 1995, 1996, 1997, 1999 Kungliga Tekniska Högskolan * (Royal Institute of Technology, Stockholm, Sweden). * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifdef HAVE_CONFIG_H #include "config.h" RCSID("$Id: rnd_keys.c,v 1.58 2001/08/21 15:32:07 assar Exp $"); #endif #include #include #ifdef KRB5 #include #elif defined(KRB4) #include #endif #include #ifdef TIME_WITH_SYS_TIME #include #include #elif defined(HAVE_SYS_TIME_H) #include #else #include #endif #ifdef HAVE_SYS_TYPES_H #include #endif #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_IO_H #include #endif #ifdef HAVE_SIGNAL_H #include #endif #ifdef HAVE_FCNTL_H #include #endif /* * Generate "random" data by checksumming a file. * * Returns -1 if there were any problems with permissions or I/O * errors. */ static int sumFile (const char *name, int len, void *res) { u_int32_t sum[2]; u_int32_t buf[1024*2]; int fd, i; fd = open (name, 0); if (fd < 0) return -1; while (len > 0) { int n = read(fd, buf, sizeof(buf)); if (n < 0) { close(fd); return n; } for (i = 0; i < (n/sizeof(buf[0])); i++) { sum[0] += buf[i]; i++; sum[1] += buf[i]; } len -= n; } close (fd); memcpy (res, &sum, sizeof(sum)); return 0; } #if 0 static int md5sumFile (const char *name, int len, int32_t sum[4]) { int32_t buf[1024*2]; int fd, cnt; struct md5 md5; fd = open (name, 0); if (fd < 0) return -1; md5_init(&md5); while (len > 0) { int n = read(fd, buf, sizeof(buf)); if (n < 0) { close(fd); return n; } md5_update(&md5, buf, n); len -= n; } md5_finito(&md5, (unsigned char *)sum); close (fd); return 0; } #endif /* * Create a sequence of random 64 bit blocks. * The sequence is indexed with a long long and * based on an initial des key used as a seed. */ static des_key_schedule sequence_seed; static u_int32_t sequence_index[2]; /* * Random number generator based on ideas from truerand in cryptolib * as described on page 424 in Applied Cryptography 2 ed. by Bruce * Schneier. */ static volatile int counter; static volatile unsigned char *gdata; /* Global data */ static volatile int igdata; /* Index into global data */ static int gsize; #if !defined(WIN32) && !defined(__EMX__) && !defined(__OS2__) && !defined(__CYGWIN32__) /* Visual C++ 4.0 (Windows95/NT) */ static RETSIGTYPE sigALRM(int sig) { if (igdata < gsize) gdata[igdata++] ^= counter & 0xff; #ifndef HAVE_SIGACTION signal(SIGALRM, sigALRM); /* Reinstall SysV signal handler */ #endif SIGRETURN(0); } #endif #if !defined(HAVE_RANDOM) && defined(HAVE_RAND) #ifndef srandom #define srandom srand #endif #ifndef random #define random rand #endif #endif #ifndef HAVE_SETITIMER static void des_not_rand_data(unsigned char *data, int size) { int i; srandom (time (NULL)); for(i = 0; i < size; ++i) data[i] ^= random() % 0x100; } #endif #if !defined(WIN32) && !defined(__EMX__) && !defined(__OS2__) && !defined(__CYGWIN32__) #ifndef HAVE_SETITIMER static void pacemaker(struct timeval *tv) { fd_set fds; pid_t pid; pid = getppid(); while(1){ FD_ZERO(&fds); FD_SET(0, &fds); select(1, &fds, NULL, NULL, tv); kill(pid, SIGALRM); } } #endif #ifdef HAVE_SIGACTION /* XXX ugly hack, should perhaps use function from roken */ static RETSIGTYPE (*fake_signal(int sig, RETSIGTYPE (*f)(int)))(int) { struct sigaction sa, osa; sa.sa_handler = f; sa.sa_flags = 0; sigemptyset(&sa.sa_mask); sigaction(sig, &sa, &osa); return osa.sa_handler; } #define signal(S, F) fake_signal((S), (F)) #endif /* * Generate size bytes of "random" data using timed interrupts. * It takes about 40ms/byte random data. * It's not neccessary to be root to run it. */ void des_rand_data(unsigned char *data, int size) { struct itimerval tv, otv; RETSIGTYPE (*osa)(int); int i, j; #ifndef HAVE_SETITIMER RETSIGTYPE (*ochld)(int); pid_t pid; #endif char *rnd_devices[] = {"/dev/random", "/dev/srandom", "/dev/urandom", NULL}; char **p; for(p = rnd_devices; *p; p++) { int fd = open(*p, O_RDONLY | O_NDELAY); if(fd >= 0 && read(fd, data, size) == size) { close(fd); return; } close(fd); } /* Paranoia? Initialize data from /dev/mem if we can read it. */ if (size >= 8) sumFile("/dev/mem", (1024*1024*2), data); gdata = data; gsize = size; igdata = 0; osa = signal(SIGALRM, sigALRM); /* Start timer */ tv.it_value.tv_sec = 0; tv.it_value.tv_usec = 10 * 1000; /* 10 ms */ tv.it_interval = tv.it_value; #ifdef HAVE_SETITIMER setitimer(ITIMER_REAL, &tv, &otv); #else ochld = signal(SIGCHLD, SIG_IGN); pid = fork(); if(pid == -1){ signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL); des_not_rand_data(data, size); return; } if(pid == 0) pacemaker(&tv.it_interval); #endif for(i = 0; i < 4; i++) { for (igdata = 0; igdata < size;) /* igdata++ in sigALRM */ counter++; for (j = 0; j < size; j++) /* Only use 2 bits each lap */ gdata[j] = (gdata[j]>>2) | (gdata[j]<<6); } #ifdef HAVE_SETITIMER setitimer(ITIMER_REAL, &otv, 0); #else kill(pid, SIGKILL); while(waitpid(pid, NULL, 0) != pid); signal(SIGCHLD, ochld != SIG_ERR ? ochld : SIG_DFL); #endif signal(SIGALRM, osa != SIG_ERR ? osa : SIG_DFL); } #else void des_rand_data(unsigned char *p, int s) { des_not_rand_data (p, s); } #endif void des_generate_random_block(des_cblock *block) { des_rand_data((unsigned char *)block, sizeof(*block)); } /* * Generate a "random" DES key. */ void des_rand_data_key(des_cblock *key) { unsigned char data[8]; des_key_schedule sched; do { des_rand_data(data, sizeof(data)); des_rand_data((unsigned char*)key, sizeof(des_cblock)); des_set_odd_parity(key); des_key_sched(key, sched); des_ecb_encrypt(&data, key, sched, DES_ENCRYPT); memset(&data, 0, sizeof(data)); memset(&sched, 0, sizeof(sched)); des_set_odd_parity(key); } while(des_is_weak_key(key)); } /* * Generate "random" data by checksumming /dev/mem * * It's neccessary to be root to run it. Returns -1 if there were any * problems with permissions. */ int des_mem_rand8(unsigned char *data) { return 1; } /* * In case the generator does not get initialized use this as fallback. */ static int initialized; static void do_initialize(void) { des_cblock default_seed; do { des_generate_random_block(&default_seed); des_set_odd_parity(&default_seed); } while (des_is_weak_key(&default_seed)); des_init_random_number_generator(&default_seed); } #define zero_long_long(ll) do { ll[0] = ll[1] = 0; } while (0) #define incr_long_long(ll) do { if (++ll[0] == 0) ++ll[1]; } while (0) #define set_sequence_number(ll) \ memcpy((char *)sequence_index, (ll), sizeof(sequence_index)); /* * Set the sequnce number to this value (a long long). */ void des_set_sequence_number(unsigned char *ll) { set_sequence_number(ll); } /* * Set the generator seed and reset the sequence number to 0. */ void des_set_random_generator_seed(des_cblock *seed) { des_key_sched(seed, sequence_seed); zero_long_long(sequence_index); initialized = 1; } /* * Generate a sequence of random des keys * using the random block sequence, fixup * parity and skip weak keys. */ int des_new_random_key(des_cblock *key) { if (!initialized) do_initialize(); do { des_ecb_encrypt((des_cblock *) sequence_index, key, sequence_seed, DES_ENCRYPT); incr_long_long(sequence_index); /* random key must have odd parity and not be weak */ des_set_odd_parity(key); } while (des_is_weak_key(key)); return(0); } /* * des_init_random_number_generator: * * Initialize the sequence of random 64 bit blocks. The input seed * can be a secret key since it should be well hidden and is also not * kept. * */ void des_init_random_number_generator(des_cblock *seed) { struct timeval now; des_cblock uniq; des_cblock new_key; gettimeofday(&now, (struct timezone *)0); des_generate_random_block(&uniq); /* Pick a unique random key from the shared sequence. */ des_set_random_generator_seed(seed); set_sequence_number((unsigned char *)&uniq); des_new_random_key(&new_key); /* Select a new nonshared sequence, */ des_set_random_generator_seed(&new_key); /* and use the current time to pick a key for the new sequence. */ set_sequence_number((unsigned char *)&now); des_new_random_key(&new_key); des_set_random_generator_seed(&new_key); } /* This is for backwards compatibility. */ void des_random_key(des_cblock ret) { des_new_random_key((des_cblock *)ret); } #ifdef TESTRUN int main() { unsigned char data[8]; int i; while (1) { if (sumFile("/dev/mem", (1024*1024*8), data) != 0) { perror("sumFile"); exit(1); } for (i = 0; i < 8; i++) printf("%02x", data[i]); printf("\n"); } } #endif #ifdef TESTRUN2 int main() { des_cblock data; int i; while (1) { do_initialize(); des_random_key(data); for (i = 0; i < 8; i++) printf("%02x", data[i]); printf("\n"); } } #endif