mirror of git://anongit.mindrot.org/openssh.git
434 lines
12 KiB
C
434 lines
12 KiB
C
/*
|
|
* Copyright (c) 2000 Damien Miller. 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 Markus Friedl.
|
|
* 4. The name of the author may not be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
|
|
*/
|
|
|
|
#include "includes.h"
|
|
|
|
#include "ssh.h"
|
|
#include "xmalloc.h"
|
|
|
|
#ifdef HAVE_OPENSSL
|
|
# include <openssl/rand.h>
|
|
# include <openssl/sha.h>
|
|
#endif
|
|
#ifdef HAVE_SSL
|
|
# include <ssl/rand.h>
|
|
# include <ssl/sha.h>
|
|
#endif
|
|
|
|
RCSID("$Id: entropy.c,v 1.3 2000/04/04 05:04:10 damien Exp $");
|
|
|
|
#ifdef EGD_SOCKET
|
|
#ifndef offsetof
|
|
# define offsetof(type, member) ((size_t) &((type *)0)->member)
|
|
#endif
|
|
/* Collect entropy from EGD */
|
|
void get_random_bytes(unsigned char *buf, int len)
|
|
{
|
|
static int egd_socket = -1;
|
|
int c;
|
|
char egd_message[2] = { 0x02, 0x00 };
|
|
struct sockaddr_un addr;
|
|
int addr_len;
|
|
|
|
memset(&addr, '\0', sizeof(addr));
|
|
addr.sun_family = AF_UNIX;
|
|
|
|
/* FIXME: compile time check? */
|
|
if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path))
|
|
fatal("Random pool path is too long");
|
|
|
|
strcpy(addr.sun_path, EGD_SOCKET);
|
|
|
|
addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET);
|
|
|
|
if (egd_socket == -1) {
|
|
egd_socket = socket(AF_UNIX, SOCK_STREAM, 0);
|
|
if (egd_socket == -1)
|
|
fatal("Couldn't create AF_UNIX socket: %s", strerror(errno));
|
|
if (connect(egd_socket, (struct sockaddr*)&addr, addr_len) == -1)
|
|
fatal("Couldn't connect to EGD socket \"%s\": %s", addr.sun_path, strerror(errno));
|
|
}
|
|
|
|
if (len > 255)
|
|
fatal("Too many bytes to read from EGD");
|
|
|
|
/* Send blocking read request to EGD */
|
|
egd_message[1] = len;
|
|
|
|
c = atomicio(write, egd_socket, egd_message, sizeof(egd_message));
|
|
if (c == -1)
|
|
fatal("Couldn't write to EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
|
|
|
|
c = atomicio(read, egd_socket, buf, len);
|
|
if (c <= 0)
|
|
fatal("Couldn't read from EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
|
|
|
|
close(EGD_SOCKET);
|
|
}
|
|
#else /* !EGD_SOCKET */
|
|
#ifdef RANDOM_POOL
|
|
/* Collect entropy from /dev/urandom or pipe */
|
|
void get_random_bytes(unsigned char *buf, int len)
|
|
{
|
|
static int random_pool = -1;
|
|
int c;
|
|
|
|
if (random_pool == -1) {
|
|
random_pool = open(RANDOM_POOL, O_RDONLY);
|
|
if (random_pool == -1)
|
|
fatal("Couldn't open random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
|
|
}
|
|
|
|
c = atomicio(read, random_pool, buf, len);
|
|
if (c <= 0)
|
|
fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
|
|
}
|
|
#endif /* RANDOM_POOL */
|
|
#endif /* EGD_SOCKET */
|
|
|
|
#if !defined(EGD_SOCKET) && !defined(RANDOM_POOL)
|
|
/*
|
|
* FIXME: proper entropy estimations. All current values are guesses
|
|
* FIXME: Need timeout for slow moving programs
|
|
* FIXME: More entropy sources
|
|
*/
|
|
|
|
double stir_from_system(void);
|
|
double stir_from_programs(void);
|
|
double stir_gettimeofday(double entropy_estimate);
|
|
double stir_clock(double entropy_estimate);
|
|
double stir_rusage(int who, double entropy_estimate);
|
|
double hash_output_from_command(const char *path, const char **args, char *hash);
|
|
|
|
typedef struct
|
|
{
|
|
/* Proportion of data that is entropy */
|
|
double rate;
|
|
/* Path to executable */
|
|
const char *path;
|
|
/* argv to pass to executable */
|
|
const char *args[5];
|
|
} entropy_source_t;
|
|
|
|
entropy_source_t entropy_sources[] = {
|
|
#ifdef PROG_LS
|
|
{ 0.002, PROG_LS, { "ls", "-alni", "/var/log", NULL } },
|
|
{ 0.002, PROG_LS, { "ls", "-alni", "/var/adm", NULL } },
|
|
{ 0.002, PROG_LS, { "ls", "-alni", "/var/mail", NULL } },
|
|
{ 0.002, PROG_LS, { "ls", "-alni", "/var/spool/mail", NULL } },
|
|
{ 0.002, PROG_LS, { "ls", "-alni", "/proc", NULL } },
|
|
{ 0.002, PROG_LS, { "ls", "-alni", "/tmp", NULL } },
|
|
#endif
|
|
#ifdef PROG_NETSTAT
|
|
{ 0.005, PROG_NETSTAT, { "netstat","-an", NULL, NULL } },
|
|
{ 0.010, PROG_NETSTAT, { "netstat","-in", NULL, NULL } },
|
|
{ 0.002, PROG_NETSTAT, { "netstat","-rn", NULL, NULL } },
|
|
{ 0.002, PROG_NETSTAT, { "netstat","-s", NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_ARP
|
|
{ 0.002, PROG_ARP, { "arp","-a","-n", NULL } },
|
|
#endif
|
|
#ifdef PROG_IFCONFIG
|
|
{ 0.002, PROG_IFCONFIG, { "ifconfig", "-a", NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_PS
|
|
{ 0.003, PROG_PS, { "ps", "laxww", NULL, NULL } },
|
|
{ 0.003, PROG_PS, { "ps", "-al", NULL, NULL } },
|
|
{ 0.003, PROG_PS, { "ps", "-efl", NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_W
|
|
{ 0.005, PROG_W, { "w", NULL, NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_WHO
|
|
{ 0.001, PROG_WHO, { "who","-i", NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_LAST
|
|
{ 0.001, PROG_LAST, { "last", NULL, NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_LASTLOG
|
|
{ 0.001, PROG_LASTLOG, { "lastlog", NULL, NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_DF
|
|
{ 0.010, PROG_DF, { "df", NULL, NULL, NULL } },
|
|
{ 0.010, PROG_DF, { "df", "-i", NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_VMSTAT
|
|
{ 0.010, PROG_VMSTAT, { "vmstat", NULL, NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_UPTIME
|
|
{ 0.001, PROG_UPTIME, { "uptime", NULL, NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_IPCS
|
|
{ 0.001, PROG_IPCS, { "-a", NULL, NULL, NULL } },
|
|
#endif
|
|
#ifdef PROG_TAIL
|
|
{ 0.001, PROG_TAIL, { "tail", "-200", "/var/log/messages", NULL, NULL } },
|
|
{ 0.001, PROG_TAIL, { "tail", "-200", "/var/log/syslog", NULL, NULL } },
|
|
{ 0.001, PROG_TAIL, { "tail", "-200", "/var/adm/messages", NULL, NULL } },
|
|
{ 0.001, PROG_TAIL, { "tail", "-200", "/var/adm/syslog", NULL, NULL } },
|
|
{ 0.001, PROG_TAIL, { "tail", "-200", "/var/log/maillog", NULL, NULL } },
|
|
{ 0.001, PROG_TAIL, { "tail", "-200", "/var/adm/maillog", NULL, NULL } },
|
|
#endif
|
|
{ 0.000, NULL, { NULL, NULL, NULL, NULL, NULL } },
|
|
};
|
|
|
|
|
|
double
|
|
stir_from_system(void)
|
|
{
|
|
double total_entropy_estimate;
|
|
long int i;
|
|
|
|
total_entropy_estimate = 0;
|
|
|
|
i = getpid();
|
|
RAND_add(&i, sizeof(i), 0.1);
|
|
total_entropy_estimate += 0.1;
|
|
|
|
i = getppid();
|
|
RAND_add(&i, sizeof(i), 0.1);
|
|
total_entropy_estimate += 0.1;
|
|
|
|
i = getuid();
|
|
RAND_add(&i, sizeof(i), 0.0);
|
|
i = getgid();
|
|
RAND_add(&i, sizeof(i), 0.0);
|
|
|
|
total_entropy_estimate += stir_gettimeofday(1.0);
|
|
total_entropy_estimate += stir_clock(0.2);
|
|
total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
|
|
|
|
return(total_entropy_estimate);
|
|
}
|
|
|
|
double
|
|
stir_from_programs(void)
|
|
{
|
|
int i;
|
|
int c;
|
|
double entropy_estimate;
|
|
double total_entropy_estimate;
|
|
char hash[SHA_DIGEST_LENGTH];
|
|
|
|
/*
|
|
* Run through list of programs twice to catch differences
|
|
*/
|
|
total_entropy_estimate = 0;
|
|
for(i = 0; i < 2; i++) {
|
|
c = 0;
|
|
while (entropy_sources[c].path != NULL) {
|
|
/* Hash output from command */
|
|
entropy_estimate = hash_output_from_command(entropy_sources[c].path,
|
|
entropy_sources[c].args, hash);
|
|
|
|
/* Scale back entropy estimate according to command's rate */
|
|
entropy_estimate *= entropy_sources[c].rate;
|
|
|
|
/* Upper bound of entropy estimate is SHA_DIGEST_LENGTH */
|
|
if (entropy_estimate > SHA_DIGEST_LENGTH)
|
|
entropy_estimate = SHA_DIGEST_LENGTH;
|
|
|
|
/* * Scale back estimates for subsequent passes through list */
|
|
entropy_estimate /= 10.0 * (i + 1.0);
|
|
|
|
/* Stir it in */
|
|
RAND_add(hash, sizeof(hash), entropy_estimate);
|
|
|
|
/* FIXME: turn this off later */
|
|
#if 1
|
|
debug("Got %0.2f bytes of entropy from %s", entropy_estimate,
|
|
entropy_sources[c].path);
|
|
#endif
|
|
|
|
total_entropy_estimate += entropy_estimate;
|
|
|
|
/* Execution times should be a little unpredictable */
|
|
total_entropy_estimate += stir_gettimeofday(0.05);
|
|
total_entropy_estimate += stir_clock(0.05);
|
|
total_entropy_estimate += stir_rusage(RUSAGE_SELF, 0.1);
|
|
total_entropy_estimate += stir_rusage(RUSAGE_CHILDREN, 0.1);
|
|
|
|
c++;
|
|
}
|
|
}
|
|
|
|
return(total_entropy_estimate);
|
|
}
|
|
|
|
double
|
|
stir_gettimeofday(double entropy_estimate)
|
|
{
|
|
struct timeval tv;
|
|
|
|
if (gettimeofday(&tv, NULL) == -1)
|
|
fatal("Couldn't gettimeofday: %s", strerror(errno));
|
|
|
|
RAND_add(&tv, sizeof(tv), entropy_estimate);
|
|
|
|
return(entropy_estimate);
|
|
}
|
|
|
|
double
|
|
stir_clock(double entropy_estimate)
|
|
{
|
|
#ifdef HAVE_CLOCK
|
|
clock_t c;
|
|
|
|
c = clock();
|
|
RAND_add(&c, sizeof(c), entropy_estimate);
|
|
|
|
return(entropy_estimate);
|
|
#else /* _HAVE_CLOCK */
|
|
return(0);
|
|
#endif /* _HAVE_CLOCK */
|
|
}
|
|
|
|
double
|
|
stir_rusage(int who, double entropy_estimate)
|
|
{
|
|
#ifdef HAVE_GETRUSAGE
|
|
struct rusage ru;
|
|
|
|
if (getrusage(who, &ru) == -1)
|
|
fatal("Couldn't getrusage: %s", strerror(errno));
|
|
|
|
RAND_add(&ru, sizeof(ru), 0.1);
|
|
|
|
return(entropy_estimate);
|
|
#else /* _HAVE_GETRUSAGE */
|
|
return(0);
|
|
#endif /* _HAVE_GETRUSAGE */
|
|
}
|
|
|
|
double
|
|
hash_output_from_command(const char *path, const char **args, char *hash)
|
|
{
|
|
static int devnull = -1;
|
|
int p[2];
|
|
pid_t pid;
|
|
int status;
|
|
char buf[2048];
|
|
int bytes_read;
|
|
int total_bytes_read;
|
|
SHA_CTX sha;
|
|
|
|
if (devnull == -1) {
|
|
devnull = open("/dev/null", O_RDWR);
|
|
if (devnull == -1)
|
|
fatal("Couldn't open /dev/null: %s", strerror(errno));
|
|
}
|
|
|
|
if (pipe(p) == -1)
|
|
fatal("Couldn't open pipe: %s", strerror(errno));
|
|
|
|
switch (pid = fork()) {
|
|
case -1: /* Error */
|
|
close(p[0]);
|
|
close(p[1]);
|
|
fatal("Couldn't fork: %s", strerror(errno));
|
|
/* NOTREACHED */
|
|
case 0: /* Child */
|
|
close(0);
|
|
close(1);
|
|
close(2);
|
|
dup2(devnull, 0);
|
|
dup2(p[1], 1);
|
|
dup2(p[1], 2);
|
|
close(p[0]);
|
|
close(p[1]);
|
|
close(devnull);
|
|
|
|
execv(path, (char**)args);
|
|
debug("(child) Couldn't exec '%s': %s", path, strerror(errno));
|
|
_exit(-1);
|
|
default: /* Parent */
|
|
break;
|
|
}
|
|
|
|
RAND_add(&pid, sizeof(&pid), 0.0);
|
|
|
|
close(p[1]);
|
|
|
|
/* Hash output from child */
|
|
SHA1_Init(&sha);
|
|
total_bytes_read = 0;
|
|
while ((bytes_read = read(p[0], buf, sizeof(buf))) > 0) {
|
|
SHA1_Update(&sha, buf, bytes_read);
|
|
total_bytes_read += bytes_read;
|
|
RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
|
|
}
|
|
SHA1_Final(hash, &sha);
|
|
|
|
close(p[0]);
|
|
|
|
if (waitpid(pid, &status, 0) == -1) {
|
|
error("Couldn't wait for child '%s' completion: %s", path,
|
|
strerror(errno));
|
|
return(-1);
|
|
}
|
|
|
|
RAND_add(&status, sizeof(&status), 0.0);
|
|
|
|
if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
|
|
return(0.0);
|
|
else
|
|
return(total_bytes_read);
|
|
}
|
|
#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
|
|
|
|
#if defined(EGD_SOCKET) || defined(RANDOM_POOL)
|
|
/*
|
|
* Seed OpenSSL's random number pool from Kernel random number generator
|
|
* or EGD
|
|
*/
|
|
void
|
|
seed_rng(void)
|
|
{
|
|
char buf[32];
|
|
|
|
debug("Seeding random number generator");
|
|
get_random_bytes(buf, sizeof(buf));
|
|
RAND_add(buf, sizeof(buf), sizeof(buf));
|
|
memset(buf, '\0', sizeof(buf));
|
|
}
|
|
#else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
|
|
/*
|
|
* Conditionally Seed OpenSSL's random number pool syscalls and program output
|
|
*/
|
|
void
|
|
seed_rng(void)
|
|
{
|
|
debug("Seeding random number generator.");
|
|
debug("OpenSSL random status is now %i\n", RAND_status());
|
|
debug("%i bytes from system calls", (int)stir_from_system());
|
|
debug("%i bytes from programs", (int)stir_from_programs());
|
|
debug("OpenSSL random status is now %i\n", RAND_status());
|
|
}
|
|
#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
|