freebsd-dev/crypto/libdes/rnd_keys.c

450 lines
10 KiB
C

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. 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.
*
* $Id$
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <des.h>
#include <des_locl.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#ifndef RETSIGTYPE
#define RETSIGTYPE void
#define SIGRETURN(x) return
#else
#define SIGRETURN(x) return (RETSIGTYPE)(x)
#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;
}
/*
* 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
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;
}
#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;
#ifdef HAVE_SETITIMER
struct itimerval otv;
#endif
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);
}
#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