blob: 8b1c4b4f47bf034f52ce117dceaebd24daa3b361 [file] [log] [blame]
Damien Miller62116dc2001-12-24 01:41:47 +11001/*
Damien Miller7b10ef42002-01-21 23:44:12 +11002 * Copyright (c) 2001-2002 Damien Miller. All rights reserved.
Damien Miller62116dc2001-12-24 01:41:47 +11003 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#include "includes.h"
26
Damien Miller3717cda2006-03-15 14:02:36 +110027#include <sys/types.h>
28#include <sys/resource.h>
29#include <sys/stat.h>
30#include <sys/wait.h>
Damien Miller8ec8c3e2006-07-10 20:35:38 +100031#include <sys/socket.h>
Darren Tucker4c655432006-08-05 15:57:40 +100032
33#include <stdarg.h>
Damien Miller2d00e632006-07-24 13:53:19 +100034#include <stddef.h>
Darren Tuckera8d51ee2007-03-13 07:35:38 +110035#include <string.h>
Damien Miller8ec8c3e2006-07-10 20:35:38 +100036
37#include <netinet/in.h>
Darren Tucker46aa3e02006-09-02 15:32:40 +100038#include <arpa/inet.h>
Damien Miller3717cda2006-03-15 14:02:36 +110039
40#ifdef HAVE_SYS_UN_H
41# include <sys/un.h>
42#endif
43
Darren Tuckerdeecec92006-07-12 22:44:34 +100044#include <errno.h>
Damien Millera1738e42006-07-10 21:33:04 +100045#include <fcntl.h>
Damien Miller9f2abc42006-07-10 20:53:08 +100046#include <pwd.h>
Damien Miller3717cda2006-03-15 14:02:36 +110047#include <signal.h>
Damien Millerb8fe89c2006-07-24 14:51:00 +100048#include <time.h>
49#include <unistd.h>
Damien Miller3717cda2006-03-15 14:02:36 +110050
Damien Miller62116dc2001-12-24 01:41:47 +110051#include <openssl/rand.h>
52#include <openssl/sha.h>
53#include <openssl/crypto.h>
54
55/* SunOS 4.4.4 needs this */
56#ifdef HAVE_FLOATINGPOINT_H
57# include <floatingpoint.h>
58#endif /* HAVE_FLOATINGPOINT_H */
59
60#include "misc.h"
61#include "xmalloc.h"
62#include "atomicio.h"
63#include "pathnames.h"
64#include "log.h"
65
Damien Miller7b10ef42002-01-21 23:44:12 +110066/* Number of bytes we write out */
67#define OUTPUT_SEED_SIZE 48
68
69/* Length of on-disk seedfiles */
70#define SEED_FILE_SIZE 1024
71
72/* Maximum number of command-line arguments to read from file */
73#define NUM_ARGS 10
74
75/* Minimum number of usable commands to be considered sufficient */
76#define MIN_ENTROPY_SOURCES 16
77
78/* Path to on-disk seed file (relative to user's home directory */
79#ifndef SSH_PRNG_SEED_FILE
80# define SSH_PRNG_SEED_FILE _PATH_SSH_USER_DIR"/prng_seed"
81#endif
82
83/* Path to PRNG commands list */
84#ifndef SSH_PRNG_COMMAND_FILE
Damien Miller05eda432002-02-10 18:32:28 +110085# define SSH_PRNG_COMMAND_FILE SSHDIR "/ssh_prng_cmds"
Damien Miller7b10ef42002-01-21 23:44:12 +110086#endif
87
Kevin Steves94435082001-12-25 04:32:58 +000088extern char *__progname;
Kevin Steves94435082001-12-25 04:32:58 +000089
Damien Miller62116dc2001-12-24 01:41:47 +110090#define WHITESPACE " \t\n"
91
92#ifndef RUSAGE_SELF
93# define RUSAGE_SELF 0
94#endif
95#ifndef RUSAGE_CHILDREN
96# define RUSAGE_CHILDREN 0
97#endif
98
Damien Millerc46cc542002-01-22 21:58:27 +110099#if !defined(PRNGD_SOCKET) && !defined(PRNGD_PORT)
Damien Miller7b10ef42002-01-21 23:44:12 +1100100# define USE_SEED_FILES
Damien Miller62116dc2001-12-24 01:41:47 +1100101#endif
102
Damien Miller7b10ef42002-01-21 23:44:12 +1100103typedef struct {
104 /* Proportion of data that is entropy */
105 double rate;
106 /* Counter goes positive if this command times out */
107 unsigned int badness;
108 /* Increases by factor of two each timeout */
109 unsigned int sticky_badness;
110 /* Path to executable */
111 char *path;
112 /* argv to pass to executable */
113 char *args[NUM_ARGS]; /* XXX: arbitrary limit */
114 /* full command string (debug) */
115 char *cmdstring;
116} entropy_cmd_t;
117
118/* slow command timeouts (all in milliseconds) */
119/* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */
120static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC;
121
122/* this is initialised from a file, by prng_read_commands() */
123static entropy_cmd_t *entropy_cmds = NULL;
124
125/* Prototypes */
126double stir_from_system(void);
127double stir_from_programs(void);
128double stir_gettimeofday(double entropy_estimate);
129double stir_clock(double entropy_estimate);
130double stir_rusage(int who, double entropy_estimate);
Kevin Steves4bdb5472002-07-28 20:42:23 +0000131double hash_command_output(entropy_cmd_t *src, unsigned char *hash);
Damien Millera8e06ce2003-11-21 23:48:55 +1100132int get_random_bytes_prngd(unsigned char *buf, int len,
Damien Miller7b10ef42002-01-21 23:44:12 +1100133 unsigned short tcp_port, char *socket_path);
134
135/*
136 * Collect 'len' bytes of entropy into 'buf' from PRNGD/EGD daemon
137 * listening either on 'tcp_port', or via Unix domain socket at *
138 * 'socket_path'.
Damien Millera8e06ce2003-11-21 23:48:55 +1100139 * Either a non-zero tcp_port or a non-null socket_path must be
Damien Miller7b10ef42002-01-21 23:44:12 +1100140 * supplied.
141 * Returns 0 on success, -1 on error
142 */
Damien Miller62116dc2001-12-24 01:41:47 +1100143int
Damien Millera8e06ce2003-11-21 23:48:55 +1100144get_random_bytes_prngd(unsigned char *buf, int len,
Damien Miller7b10ef42002-01-21 23:44:12 +1100145 unsigned short tcp_port, char *socket_path)
Damien Miller62116dc2001-12-24 01:41:47 +1100146{
Damien Miller7b10ef42002-01-21 23:44:12 +1100147 int fd, addr_len, rval, errors;
Damien Miller52c8afe2005-06-19 10:19:43 +1000148 u_char msg[2];
Damien Miller7b10ef42002-01-21 23:44:12 +1100149 struct sockaddr_storage addr;
150 struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
151 struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr;
Damien Miller62116dc2001-12-24 01:41:47 +1100152 mysig_t old_sigpipe;
153
Damien Miller7b10ef42002-01-21 23:44:12 +1100154 /* Sanity checks */
155 if (socket_path == NULL && tcp_port == 0)
156 fatal("You must specify a port or a socket");
157 if (socket_path != NULL &&
158 strlen(socket_path) >= sizeof(addr_un->sun_path))
159 fatal("Random pool path is too long");
Damien Miller52c8afe2005-06-19 10:19:43 +1000160 if (len <= 0 || len > 255)
161 fatal("Too many bytes (%d) to read from PRNGD", len);
Damien Miller62116dc2001-12-24 01:41:47 +1100162
163 memset(&addr, '\0', sizeof(addr));
164
Damien Miller7b10ef42002-01-21 23:44:12 +1100165 if (tcp_port != 0) {
166 addr_in->sin_family = AF_INET;
167 addr_in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
168 addr_in->sin_port = htons(tcp_port);
169 addr_len = sizeof(*addr_in);
170 } else {
171 addr_un->sun_family = AF_UNIX;
172 strlcpy(addr_un->sun_path, socket_path,
173 sizeof(addr_un->sun_path));
174 addr_len = offsetof(struct sockaddr_un, sun_path) +
175 strlen(socket_path) + 1;
176 }
Damien Miller62116dc2001-12-24 01:41:47 +1100177
178 old_sigpipe = mysignal(SIGPIPE, SIG_IGN);
179
Damien Miller7b10ef42002-01-21 23:44:12 +1100180 errors = 0;
181 rval = -1;
Damien Miller62116dc2001-12-24 01:41:47 +1100182reopen:
Damien Miller7b10ef42002-01-21 23:44:12 +1100183 fd = socket(addr.ss_family, SOCK_STREAM, 0);
Damien Miller62116dc2001-12-24 01:41:47 +1100184 if (fd == -1) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100185 error("Couldn't create socket: %s", strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100186 goto done;
187 }
Damien Miller62116dc2001-12-24 01:41:47 +1100188
189 if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100190 if (tcp_port != 0) {
191 error("Couldn't connect to PRNGD port %d: %s",
192 tcp_port, strerror(errno));
193 } else {
194 error("Couldn't connect to PRNGD socket \"%s\": %s",
195 addr_un->sun_path, strerror(errno));
196 }
Damien Miller62116dc2001-12-24 01:41:47 +1100197 goto done;
198 }
199
200 /* Send blocking read request to PRNGD */
201 msg[0] = 0x02;
202 msg[1] = len;
203
Darren Tucker8661b562003-07-06 15:20:46 +1000204 if (atomicio(vwrite, fd, msg, sizeof(msg)) != sizeof(msg)) {
Damien Miller62116dc2001-12-24 01:41:47 +1100205 if (errno == EPIPE && errors < 10) {
206 close(fd);
207 errors++;
208 goto reopen;
209 }
210 error("Couldn't write to PRNGD socket: %s",
211 strerror(errno));
212 goto done;
213 }
214
Damien Miller52c8afe2005-06-19 10:19:43 +1000215 if (atomicio(read, fd, buf, len) != (size_t)len) {
Damien Miller62116dc2001-12-24 01:41:47 +1100216 if (errno == EPIPE && errors < 10) {
217 close(fd);
218 errors++;
219 goto reopen;
220 }
221 error("Couldn't read from PRNGD socket: %s",
222 strerror(errno));
223 goto done;
224 }
225
Damien Miller7b10ef42002-01-21 23:44:12 +1100226 rval = 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100227done:
228 mysignal(SIGPIPE, old_sigpipe);
229 if (fd != -1)
230 close(fd);
Damien Miller7b10ef42002-01-21 23:44:12 +1100231 return rval;
Damien Miller62116dc2001-12-24 01:41:47 +1100232}
233
Darren Tucker8686ed72004-12-20 12:05:08 +1100234static int
235seed_from_prngd(unsigned char *buf, size_t bytes)
236{
237#ifdef PRNGD_PORT
238 debug("trying egd/prngd port %d", PRNGD_PORT);
239 if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0)
240 return 0;
241#endif
242#ifdef PRNGD_SOCKET
243 debug("trying egd/prngd socket %s", PRNGD_SOCKET);
244 if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0)
245 return 0;
246#endif
247 return -1;
248}
249
Damien Miller62116dc2001-12-24 01:41:47 +1100250double
251stir_gettimeofday(double entropy_estimate)
252{
253 struct timeval tv;
254
255 if (gettimeofday(&tv, NULL) == -1)
256 fatal("Couldn't gettimeofday: %s", strerror(errno));
257
258 RAND_add(&tv, sizeof(tv), entropy_estimate);
259
Damien Miller7b10ef42002-01-21 23:44:12 +1100260 return entropy_estimate;
Damien Miller62116dc2001-12-24 01:41:47 +1100261}
262
263double
264stir_clock(double entropy_estimate)
265{
266#ifdef HAVE_CLOCK
267 clock_t c;
268
269 c = clock();
270 RAND_add(&c, sizeof(c), entropy_estimate);
271
Damien Miller7b10ef42002-01-21 23:44:12 +1100272 return entropy_estimate;
Damien Miller62116dc2001-12-24 01:41:47 +1100273#else /* _HAVE_CLOCK */
Damien Miller7b10ef42002-01-21 23:44:12 +1100274 return 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100275#endif /* _HAVE_CLOCK */
276}
277
278double
279stir_rusage(int who, double entropy_estimate)
280{
281#ifdef HAVE_GETRUSAGE
282 struct rusage ru;
283
284 if (getrusage(who, &ru) == -1)
Damien Miller7b10ef42002-01-21 23:44:12 +1100285 return 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100286
287 RAND_add(&ru, sizeof(ru), entropy_estimate);
288
Damien Miller7b10ef42002-01-21 23:44:12 +1100289 return entropy_estimate;
Damien Miller62116dc2001-12-24 01:41:47 +1100290#else /* _HAVE_GETRUSAGE */
Damien Miller7b10ef42002-01-21 23:44:12 +1100291 return 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100292#endif /* _HAVE_GETRUSAGE */
293}
294
Damien Miller62116dc2001-12-24 01:41:47 +1100295static int
Damien Miller7b10ef42002-01-21 23:44:12 +1100296timeval_diff(struct timeval *t1, struct timeval *t2)
297{
Damien Miller62116dc2001-12-24 01:41:47 +1100298 int secdiff, usecdiff;
299
300 secdiff = t2->tv_sec - t1->tv_sec;
301 usecdiff = (secdiff*1000000) + (t2->tv_usec - t1->tv_usec);
302 return (int)(usecdiff / 1000);
303}
304
305double
Kevin Steves4bdb5472002-07-28 20:42:23 +0000306hash_command_output(entropy_cmd_t *src, unsigned char *hash)
Damien Miller62116dc2001-12-24 01:41:47 +1100307{
Damien Miller7b10ef42002-01-21 23:44:12 +1100308 char buf[8192];
Damien Miller62116dc2001-12-24 01:41:47 +1100309 fd_set rdset;
Damien Miller7b10ef42002-01-21 23:44:12 +1100310 int bytes_read, cmd_eof, error_abort, msec_elapsed, p[2];
311 int status, total_bytes_read;
312 static int devnull = -1;
Damien Miller62116dc2001-12-24 01:41:47 +1100313 pid_t pid;
Damien Miller62116dc2001-12-24 01:41:47 +1100314 SHA_CTX sha;
Damien Miller7b10ef42002-01-21 23:44:12 +1100315 struct timeval tv_start, tv_current;
Damien Miller62116dc2001-12-24 01:41:47 +1100316
317 debug3("Reading output from \'%s\'", src->cmdstring);
318
319 if (devnull == -1) {
320 devnull = open("/dev/null", O_RDWR);
321 if (devnull == -1)
Damien Millera8e06ce2003-11-21 23:48:55 +1100322 fatal("Couldn't open /dev/null: %s",
Damien Miller7b10ef42002-01-21 23:44:12 +1100323 strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100324 }
325
326 if (pipe(p) == -1)
327 fatal("Couldn't open pipe: %s", strerror(errno));
328
329 (void)gettimeofday(&tv_start, NULL); /* record start time */
330
331 switch (pid = fork()) {
332 case -1: /* Error */
333 close(p[0]);
334 close(p[1]);
335 fatal("Couldn't fork: %s", strerror(errno));
336 /* NOTREACHED */
337 case 0: /* Child */
338 dup2(devnull, STDIN_FILENO);
339 dup2(p[1], STDOUT_FILENO);
340 dup2(p[1], STDERR_FILENO);
341 close(p[0]);
342 close(p[1]);
343 close(devnull);
344
345 execv(src->path, (char**)(src->args));
Damien Miller7b10ef42002-01-21 23:44:12 +1100346
Damien Millera8e06ce2003-11-21 23:48:55 +1100347 debug("(child) Couldn't exec '%s': %s",
Damien Miller7b10ef42002-01-21 23:44:12 +1100348 src->cmdstring, strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100349 _exit(-1);
350 default: /* Parent */
351 break;
352 }
353
354 RAND_add(&pid, sizeof(&pid), 0.0);
355
356 close(p[1]);
357
358 /* Hash output from child */
359 SHA1_Init(&sha);
Damien Miller62116dc2001-12-24 01:41:47 +1100360
Damien Miller7b10ef42002-01-21 23:44:12 +1100361 cmd_eof = error_abort = msec_elapsed = total_bytes_read = 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100362 while (!error_abort && !cmd_eof) {
363 int ret;
364 struct timeval tv;
365 int msec_remaining;
366
367 (void) gettimeofday(&tv_current, 0);
Damien Miller7b10ef42002-01-21 23:44:12 +1100368 msec_elapsed = timeval_diff(&tv_start, &tv_current);
Damien Miller62116dc2001-12-24 01:41:47 +1100369 if (msec_elapsed >= entropy_timeout_current) {
370 error_abort=1;
371 continue;
372 }
373 msec_remaining = entropy_timeout_current - msec_elapsed;
374
375 FD_ZERO(&rdset);
376 FD_SET(p[0], &rdset);
Damien Miller7b10ef42002-01-21 23:44:12 +1100377 tv.tv_sec = msec_remaining / 1000;
Damien Miller62116dc2001-12-24 01:41:47 +1100378 tv.tv_usec = (msec_remaining % 1000) * 1000;
379
Damien Miller7b10ef42002-01-21 23:44:12 +1100380 ret = select(p[0] + 1, &rdset, NULL, NULL, &tv);
Damien Miller62116dc2001-12-24 01:41:47 +1100381
382 RAND_add(&tv, sizeof(tv), 0.0);
383
384 switch (ret) {
385 case 0:
386 /* timer expired */
387 error_abort = 1;
Damien Miller5a5da882002-10-21 10:13:35 +1000388 kill(pid, SIGINT);
Damien Miller62116dc2001-12-24 01:41:47 +1100389 break;
390 case 1:
391 /* command input */
392 do {
393 bytes_read = read(p[0], buf, sizeof(buf));
394 } while (bytes_read == -1 && errno == EINTR);
395 RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
396 if (bytes_read == -1) {
397 error_abort = 1;
398 break;
399 } else if (bytes_read) {
400 SHA1_Update(&sha, buf, bytes_read);
401 total_bytes_read += bytes_read;
402 } else {
403 cmd_eof = 1;
404 }
405 break;
406 case -1:
407 default:
408 /* error */
Damien Millera8e06ce2003-11-21 23:48:55 +1100409 debug("Command '%s': select() failed: %s",
Damien Miller7b10ef42002-01-21 23:44:12 +1100410 src->cmdstring, strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100411 error_abort = 1;
412 break;
413 }
414 }
415
416 SHA1_Final(hash, &sha);
417
418 close(p[0]);
419
420 debug3("Time elapsed: %d msec", msec_elapsed);
421
422 if (waitpid(pid, &status, 0) == -1) {
Damien Millerb6f72f52005-07-17 17:26:43 +1000423 error("Couldn't wait for child '%s' completion: %s",
424 src->cmdstring, strerror(errno));
Damien Miller7b10ef42002-01-21 23:44:12 +1100425 return 0.0;
Damien Miller62116dc2001-12-24 01:41:47 +1100426 }
427
428 RAND_add(&status, sizeof(&status), 0.0);
429
430 if (error_abort) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100431 /*
432 * Closing p[0] on timeout causes the entropy command to
Damien Millera8e06ce2003-11-21 23:48:55 +1100433 * SIGPIPE. Take whatever output we got, and mark this
434 * command as slow
Damien Miller7b10ef42002-01-21 23:44:12 +1100435 */
Damien Miller62116dc2001-12-24 01:41:47 +1100436 debug2("Command '%s' timed out", src->cmdstring);
437 src->sticky_badness *= 2;
438 src->badness = src->sticky_badness;
Damien Miller7b10ef42002-01-21 23:44:12 +1100439 return total_bytes_read;
Damien Miller62116dc2001-12-24 01:41:47 +1100440 }
441
442 if (WIFEXITED(status)) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100443 if (WEXITSTATUS(status) == 0) {
444 return total_bytes_read;
Damien Miller62116dc2001-12-24 01:41:47 +1100445 } else {
Damien Miller7b10ef42002-01-21 23:44:12 +1100446 debug2("Command '%s' exit status was %d",
447 src->cmdstring, WEXITSTATUS(status));
Damien Miller62116dc2001-12-24 01:41:47 +1100448 src->badness = src->sticky_badness = 128;
Damien Miller7b10ef42002-01-21 23:44:12 +1100449 return 0.0;
Damien Miller62116dc2001-12-24 01:41:47 +1100450 }
451 } else if (WIFSIGNALED(status)) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100452 debug2("Command '%s' returned on uncaught signal %d !",
453 src->cmdstring, status);
Damien Miller62116dc2001-12-24 01:41:47 +1100454 src->badness = src->sticky_badness = 128;
Damien Miller7b10ef42002-01-21 23:44:12 +1100455 return 0.0;
Damien Miller62116dc2001-12-24 01:41:47 +1100456 } else
Damien Miller7b10ef42002-01-21 23:44:12 +1100457 return 0.0;
458}
459
460double
461stir_from_system(void)
462{
463 double total_entropy_estimate;
464 long int i;
465
466 total_entropy_estimate = 0;
467
468 i = getpid();
469 RAND_add(&i, sizeof(i), 0.5);
470 total_entropy_estimate += 0.1;
471
472 i = getppid();
473 RAND_add(&i, sizeof(i), 0.5);
474 total_entropy_estimate += 0.1;
475
476 i = getuid();
477 RAND_add(&i, sizeof(i), 0.0);
478 i = getgid();
479 RAND_add(&i, sizeof(i), 0.0);
480
481 total_entropy_estimate += stir_gettimeofday(1.0);
482 total_entropy_estimate += stir_clock(0.5);
483 total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
484
485 return total_entropy_estimate;
486}
487
488double
489stir_from_programs(void)
490{
491 int c;
492 double entropy, total_entropy;
Kevin Steves4bdb5472002-07-28 20:42:23 +0000493 unsigned char hash[SHA_DIGEST_LENGTH];
Damien Miller7b10ef42002-01-21 23:44:12 +1100494
495 total_entropy = 0;
496 for(c = 0; entropy_cmds[c].path != NULL; c++) {
497 if (!entropy_cmds[c].badness) {
498 /* Hash output from command */
499 entropy = hash_command_output(&entropy_cmds[c],
500 hash);
501
502 /* Scale back estimate by command's rate */
503 entropy *= entropy_cmds[c].rate;
504
505 /* Upper bound of entropy is SHA_DIGEST_LENGTH */
506 if (entropy > SHA_DIGEST_LENGTH)
507 entropy = SHA_DIGEST_LENGTH;
508
509 /* Stir it in */
510 RAND_add(hash, sizeof(hash), entropy);
511
Damien Millera8e06ce2003-11-21 23:48:55 +1100512 debug3("Got %0.2f bytes of entropy from '%s'",
Damien Miller7b10ef42002-01-21 23:44:12 +1100513 entropy, entropy_cmds[c].cmdstring);
514
515 total_entropy += entropy;
516
517 /* Execution time should be a bit unpredictable */
518 total_entropy += stir_gettimeofday(0.05);
519 total_entropy += stir_clock(0.05);
520 total_entropy += stir_rusage(RUSAGE_SELF, 0.1);
521 total_entropy += stir_rusage(RUSAGE_CHILDREN, 0.1);
522 } else {
523 debug2("Command '%s' disabled (badness %d)",
Damien Millera8e06ce2003-11-21 23:48:55 +1100524 entropy_cmds[c].cmdstring,
Damien Miller7b10ef42002-01-21 23:44:12 +1100525 entropy_cmds[c].badness);
526
527 if (entropy_cmds[c].badness > 0)
528 entropy_cmds[c].badness--;
529 }
530 }
531
532 return total_entropy;
Damien Miller62116dc2001-12-24 01:41:47 +1100533}
534
535/*
536 * prng seedfile functions
537 */
538int
Damien Miller7b10ef42002-01-21 23:44:12 +1100539prng_check_seedfile(char *filename)
540{
Damien Miller62116dc2001-12-24 01:41:47 +1100541 struct stat st;
542
Damien Miller7b10ef42002-01-21 23:44:12 +1100543 /*
Damien Millera8e06ce2003-11-21 23:48:55 +1100544 * XXX raceable: eg replace seed between this stat and subsequent
545 * open. Not such a problem because we don't really trust the
Damien Miller7b10ef42002-01-21 23:44:12 +1100546 * seed file anyway.
547 * XXX: use secure path checking as elsewhere in OpenSSH
548 */
Damien Miller62116dc2001-12-24 01:41:47 +1100549 if (lstat(filename, &st) == -1) {
550 /* Give up on hard errors */
551 if (errno != ENOENT)
Damien Miller7b10ef42002-01-21 23:44:12 +1100552 debug("WARNING: Couldn't stat random seed file "
553 "\"%.100s\": %s", filename, strerror(errno));
554 return 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100555 }
556
557 /* regular file? */
558 if (!S_ISREG(st.st_mode))
Damien Miller7b10ef42002-01-21 23:44:12 +1100559 fatal("PRNG seedfile %.100s is not a regular file",
560 filename);
Damien Miller62116dc2001-12-24 01:41:47 +1100561
562 /* mode 0600, owned by root or the current user? */
563 if (((st.st_mode & 0177) != 0) || !(st.st_uid == getuid())) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100564 debug("WARNING: PRNG seedfile %.100s must be mode 0600, "
Damien Millerc46b6bc2003-05-16 15:51:44 +1000565 "owned by uid %li", filename, (long int)getuid());
Damien Miller7b10ef42002-01-21 23:44:12 +1100566 return 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100567 }
568
Damien Miller7b10ef42002-01-21 23:44:12 +1100569 return 1;
Damien Miller62116dc2001-12-24 01:41:47 +1100570}
571
572void
Damien Miller7b10ef42002-01-21 23:44:12 +1100573prng_write_seedfile(void)
574{
Damien Millered462d92005-02-16 13:02:45 +1100575 int fd, save_errno;
Kevin Steves4bdb5472002-07-28 20:42:23 +0000576 unsigned char seed[SEED_FILE_SIZE];
Damien Millered462d92005-02-16 13:02:45 +1100577 char filename[MAXPATHLEN], tmpseed[MAXPATHLEN];
Damien Miller62116dc2001-12-24 01:41:47 +1100578 struct passwd *pw;
Damien Millered462d92005-02-16 13:02:45 +1100579 mode_t old_umask;
Damien Miller62116dc2001-12-24 01:41:47 +1100580
581 pw = getpwuid(getuid());
582 if (pw == NULL)
Damien Miller7b10ef42002-01-21 23:44:12 +1100583 fatal("Couldn't get password entry for current user "
Damien Millerc46b6bc2003-05-16 15:51:44 +1000584 "(%li): %s", (long int)getuid(), strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100585
586 /* Try to ensure that the parent directory is there */
587 snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
Damien Miller7b10ef42002-01-21 23:44:12 +1100588 _PATH_SSH_USER_DIR);
Darren Tuckerdaf6ff42006-07-05 21:35:48 +1000589 if (mkdir(filename, 0700) < 0 && errno != EEXIST)
590 fatal("mkdir %.200s: %s", filename, strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100591
592 snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
Damien Miller7b10ef42002-01-21 23:44:12 +1100593 SSH_PRNG_SEED_FILE);
Damien Miller62116dc2001-12-24 01:41:47 +1100594
Damien Millered462d92005-02-16 13:02:45 +1100595 strlcpy(tmpseed, filename, sizeof(tmpseed));
596 if (strlcat(tmpseed, ".XXXXXXXXXX", sizeof(tmpseed)) >=
597 sizeof(tmpseed))
598 fatal("PRNG seed filename too long");
Damien Miller62116dc2001-12-24 01:41:47 +1100599
Damien Millercafbcc72003-03-17 16:13:53 +1100600 if (RAND_bytes(seed, sizeof(seed)) <= 0)
Ben Lindstromda4d9cf2003-09-22 15:36:15 +0000601 fatal("PRNG seed extraction failed");
Damien Miller62116dc2001-12-24 01:41:47 +1100602
603 /* Don't care if the seed doesn't exist */
604 prng_check_seedfile(filename);
605
Damien Millered462d92005-02-16 13:02:45 +1100606 old_umask = umask(0177);
607
608 if ((fd = mkstemp(tmpseed)) == -1) {
609 debug("WARNING: couldn't make temporary PRNG seedfile %.100s "
610 "(%.100s)", tmpseed, strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100611 } else {
Damien Millered462d92005-02-16 13:02:45 +1100612 debug("writing PRNG seed to file %.100s", tmpseed);
613 if (atomicio(vwrite, fd, &seed, sizeof(seed)) < sizeof(seed)) {
614 save_errno = errno;
615 close(fd);
616 unlink(tmpseed);
Damien Miller7b10ef42002-01-21 23:44:12 +1100617 fatal("problem writing PRNG seedfile %.100s "
Damien Millered462d92005-02-16 13:02:45 +1100618 "(%.100s)", filename, strerror(save_errno));
619 }
Damien Miller62116dc2001-12-24 01:41:47 +1100620 close(fd);
Damien Millered462d92005-02-16 13:02:45 +1100621 debug("moving temporary PRNG seed to file %.100s", filename);
622 if (rename(tmpseed, filename) == -1) {
623 save_errno = errno;
624 unlink(tmpseed);
625 fatal("problem renaming PRNG seedfile from %.100s "
Damien Miller94cf4c82005-07-17 17:04:47 +1000626 "to %.100s (%.100s)", tmpseed, filename,
Damien Millered462d92005-02-16 13:02:45 +1100627 strerror(save_errno));
628 }
Damien Miller62116dc2001-12-24 01:41:47 +1100629 }
Damien Millered462d92005-02-16 13:02:45 +1100630 umask(old_umask);
Damien Miller62116dc2001-12-24 01:41:47 +1100631}
632
633void
Damien Miller7b10ef42002-01-21 23:44:12 +1100634prng_read_seedfile(void)
635{
Damien Miller62116dc2001-12-24 01:41:47 +1100636 int fd;
Damien Miller7b10ef42002-01-21 23:44:12 +1100637 char seed[SEED_FILE_SIZE], filename[MAXPATHLEN];
Damien Miller62116dc2001-12-24 01:41:47 +1100638 struct passwd *pw;
639
640 pw = getpwuid(getuid());
641 if (pw == NULL)
Damien Miller7b10ef42002-01-21 23:44:12 +1100642 fatal("Couldn't get password entry for current user "
Damien Millerc46b6bc2003-05-16 15:51:44 +1000643 "(%li): %s", (long int)getuid(), strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100644
645 snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
646 SSH_PRNG_SEED_FILE);
647
648 debug("loading PRNG seed from file %.100s", filename);
649
650 if (!prng_check_seedfile(filename)) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100651 verbose("Random seed file not found or invalid, ignoring.");
Damien Miller62116dc2001-12-24 01:41:47 +1100652 return;
653 }
654
655 /* open the file and read in the seed */
656 fd = open(filename, O_RDONLY);
657 if (fd == -1)
Damien Miller7b10ef42002-01-21 23:44:12 +1100658 fatal("could not open PRNG seedfile %.100s (%.100s)",
659 filename, strerror(errno));
Damien Miller62116dc2001-12-24 01:41:47 +1100660
Damien Miller7b10ef42002-01-21 23:44:12 +1100661 if (atomicio(read, fd, &seed, sizeof(seed)) < sizeof(seed)) {
662 verbose("invalid or short read from PRNG seedfile "
663 "%.100s - ignoring", filename);
Damien Miller62116dc2001-12-24 01:41:47 +1100664 memset(seed, '\0', sizeof(seed));
665 }
666 close(fd);
667
668 /* stir in the seed, with estimated entropy zero */
669 RAND_add(&seed, sizeof(seed), 0.0);
670}
671
672
673/*
674 * entropy command initialisation functions
675 */
676int
677prng_read_commands(char *cmdfilename)
678{
Damien Miller7b10ef42002-01-21 23:44:12 +1100679 char cmd[SEED_FILE_SIZE], *cp, line[1024], path[SEED_FILE_SIZE];
Damien Miller62116dc2001-12-24 01:41:47 +1100680 double est;
Damien Miller7b10ef42002-01-21 23:44:12 +1100681 entropy_cmd_t *entcmd;
682 FILE *f;
683 int cur_cmd, linenum, num_cmds, arg;
Damien Miller62116dc2001-12-24 01:41:47 +1100684
Damien Miller7b10ef42002-01-21 23:44:12 +1100685 if ((f = fopen(cmdfilename, "r")) == NULL) {
Damien Miller62116dc2001-12-24 01:41:47 +1100686 fatal("couldn't read entropy commands file %.100s: %.100s",
687 cmdfilename, strerror(errno));
688 }
689
Damien Miller7b10ef42002-01-21 23:44:12 +1100690 num_cmds = 64;
Darren Tuckerd8093e42006-05-04 16:24:34 +1000691 entcmd = xcalloc(num_cmds, sizeof(entropy_cmd_t));
Damien Miller62116dc2001-12-24 01:41:47 +1100692
693 /* Read in file */
Damien Miller7b10ef42002-01-21 23:44:12 +1100694 cur_cmd = linenum = 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100695 while (fgets(line, sizeof(line), f)) {
Damien Miller62116dc2001-12-24 01:41:47 +1100696 linenum++;
697
Damien Miller7b10ef42002-01-21 23:44:12 +1100698 /* Skip leading whitespace, blank lines and comments */
Damien Miller62116dc2001-12-24 01:41:47 +1100699 cp = line + strspn(line, WHITESPACE);
700 if ((*cp == 0) || (*cp == '#'))
701 continue; /* done with this line */
702
Damien Miller7b10ef42002-01-21 23:44:12 +1100703 /*
Damien Millera8e06ce2003-11-21 23:48:55 +1100704 * The first non-whitespace char should be a double quote
Damien Miller7b10ef42002-01-21 23:44:12 +1100705 * delimiting the commandline
706 */
Damien Miller62116dc2001-12-24 01:41:47 +1100707 if (*cp != '"') {
Damien Miller7b10ef42002-01-21 23:44:12 +1100708 error("bad entropy command, %.100s line %d",
709 cmdfilename, linenum);
Damien Miller62116dc2001-12-24 01:41:47 +1100710 continue;
711 }
712
Damien Miller7b10ef42002-01-21 23:44:12 +1100713 /*
714 * First token, command args (incl. argv[0]) in double
715 * quotes
716 */
Damien Miller62116dc2001-12-24 01:41:47 +1100717 cp = strtok(cp, "\"");
718 if (cp == NULL) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100719 error("missing or bad command string, %.100s "
720 "line %d -- ignored", cmdfilename, linenum);
Damien Miller62116dc2001-12-24 01:41:47 +1100721 continue;
722 }
723 strlcpy(cmd, cp, sizeof(cmd));
724
Damien Miller7b10ef42002-01-21 23:44:12 +1100725 /* Second token, full command path */
Damien Miller62116dc2001-12-24 01:41:47 +1100726 if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100727 error("missing command path, %.100s "
728 "line %d -- ignored", cmdfilename, linenum);
Damien Miller62116dc2001-12-24 01:41:47 +1100729 continue;
730 }
731
Damien Miller7b10ef42002-01-21 23:44:12 +1100732 /* Did configure mark this as dead? */
Damien Miller62116dc2001-12-24 01:41:47 +1100733 if (strncmp("undef", cp, 5) == 0)
734 continue;
735
736 strlcpy(path, cp, sizeof(path));
737
Damien Miller7b10ef42002-01-21 23:44:12 +1100738 /* Third token, entropy rate estimate for this command */
Damien Miller62116dc2001-12-24 01:41:47 +1100739 if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100740 error("missing entropy estimate, %.100s "
741 "line %d -- ignored", cmdfilename, linenum);
Damien Miller62116dc2001-12-24 01:41:47 +1100742 continue;
743 }
Damien Miller7b10ef42002-01-21 23:44:12 +1100744 est = strtod(cp, NULL);
Damien Miller62116dc2001-12-24 01:41:47 +1100745
746 /* end of line */
747 if ((cp = strtok(NULL, WHITESPACE)) != NULL) {
Damien Miller7b10ef42002-01-21 23:44:12 +1100748 error("garbage at end of line %d in %.100s "
749 "-- ignored", linenum, cmdfilename);
Damien Miller62116dc2001-12-24 01:41:47 +1100750 continue;
751 }
752
753 /* save the command for debug messages */
754 entcmd[cur_cmd].cmdstring = xstrdup(cmd);
755
756 /* split the command args */
757 cp = strtok(cmd, WHITESPACE);
758 arg = 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100759 do {
Damien Miller7b10ef42002-01-21 23:44:12 +1100760 entcmd[cur_cmd].args[arg] = xstrdup(cp);
Damien Miller62116dc2001-12-24 01:41:47 +1100761 arg++;
Damien Miller7b10ef42002-01-21 23:44:12 +1100762 } while(arg < NUM_ARGS && (cp = strtok(NULL, WHITESPACE)));
Damien Miller62116dc2001-12-24 01:41:47 +1100763
764 if (strtok(NULL, WHITESPACE))
Damien Miller7b10ef42002-01-21 23:44:12 +1100765 error("ignored extra commands (max %d), %.100s "
766 "line %d", NUM_ARGS, cmdfilename, linenum);
Damien Miller62116dc2001-12-24 01:41:47 +1100767
768 /* Copy the command path and rate estimate */
769 entcmd[cur_cmd].path = xstrdup(path);
770 entcmd[cur_cmd].rate = est;
771
772 /* Initialise other values */
773 entcmd[cur_cmd].sticky_badness = 1;
774
775 cur_cmd++;
776
Damien Miller7b10ef42002-01-21 23:44:12 +1100777 /*
778 * If we've filled the array, reallocate it twice the size
Damien Millera8e06ce2003-11-21 23:48:55 +1100779 * Do this now because even if this we're on the last
Damien Miller7b10ef42002-01-21 23:44:12 +1100780 * command we need another slot to mark the last entry
781 */
Damien Miller62116dc2001-12-24 01:41:47 +1100782 if (cur_cmd == num_cmds) {
783 num_cmds *= 2;
Damien Miller36812092006-03-26 14:22:47 +1100784 entcmd = xrealloc(entcmd, num_cmds,
Damien Miller7b10ef42002-01-21 23:44:12 +1100785 sizeof(entropy_cmd_t));
Damien Miller62116dc2001-12-24 01:41:47 +1100786 }
787 }
788
789 /* zero the last entry */
Damien Miller7b10ef42002-01-21 23:44:12 +1100790 memset(&entcmd[cur_cmd], '\0', sizeof(entropy_cmd_t));
Damien Miller62116dc2001-12-24 01:41:47 +1100791
792 /* trim to size */
Damien Miller36812092006-03-26 14:22:47 +1100793 entropy_cmds = xrealloc(entcmd, (cur_cmd + 1),
Damien Miller7b10ef42002-01-21 23:44:12 +1100794 sizeof(entropy_cmd_t));
Damien Miller62116dc2001-12-24 01:41:47 +1100795
Damien Miller7b10ef42002-01-21 23:44:12 +1100796 debug("Loaded %d entropy commands from %.100s", cur_cmd,
797 cmdfilename);
Damien Miller62116dc2001-12-24 01:41:47 +1100798
Darren Tuckerf58b29d2006-05-17 22:24:56 +1000799 fclose(f);
Damien Miller7b10ef42002-01-21 23:44:12 +1100800 return cur_cmd < MIN_ENTROPY_SOURCES ? -1 : 0;
Damien Miller62116dc2001-12-24 01:41:47 +1100801}
802
Damien Miller32e48182002-04-14 19:27:12 +1000803void
804usage(void)
805{
806 fprintf(stderr, "Usage: %s [options]\n", __progname);
807 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
808 fprintf(stderr, " Multiple -v increases verbosity.\n");
Damien Miller7daf0442004-08-23 21:52:08 +1000809 fprintf(stderr, " -x Force output in hexadecimal (for debugging)\n");
Damien Miller32e48182002-04-14 19:27:12 +1000810 fprintf(stderr, " -X Force output in binary\n");
811 fprintf(stderr, " -b bytes Number of bytes to output (default %d)\n",
812 OUTPUT_SEED_SIZE);
813}
814
Damien Millera8e06ce2003-11-21 23:48:55 +1100815int
Damien Miller62116dc2001-12-24 01:41:47 +1100816main(int argc, char **argv)
817{
Damien Miller32e48182002-04-14 19:27:12 +1000818 unsigned char *buf;
819 int ret, ch, debug_level, output_hex, bytes;
820 extern char *optarg;
821 LogLevel ll;
Damien Miller62116dc2001-12-24 01:41:47 +1100822
Damien Miller59d3d5b2003-08-22 09:34:41 +1000823 __progname = ssh_get_progname(argv[0]);
Damien Miller62116dc2001-12-24 01:41:47 +1100824 log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
825
Damien Miller32e48182002-04-14 19:27:12 +1000826 ll = SYSLOG_LEVEL_INFO;
827 debug_level = output_hex = 0;
828 bytes = OUTPUT_SEED_SIZE;
829
830 /* Don't write binary data to a tty, unless we are forced to */
831 if (isatty(STDOUT_FILENO))
832 output_hex = 1;
Damien Miller787b2ec2003-11-21 23:56:47 +1100833
Damien Miller32e48182002-04-14 19:27:12 +1000834 while ((ch = getopt(argc, argv, "vxXhb:")) != -1) {
835 switch (ch) {
836 case 'v':
837 if (debug_level < 3)
838 ll = SYSLOG_LEVEL_DEBUG1 + debug_level++;
839 break;
840 case 'x':
841 output_hex = 1;
842 break;
843 case 'X':
844 output_hex = 0;
845 break;
846 case 'b':
847 if ((bytes = atoi(optarg)) <= 0)
848 fatal("Invalid number of output bytes");
849 break;
850 case 'h':
851 usage();
852 exit(0);
853 default:
854 error("Invalid commandline option");
855 usage();
856 }
857 }
858
859 log_init(argv[0], ll, SYSLOG_FACILITY_USER, 1);
Damien Miller787b2ec2003-11-21 23:56:47 +1100860
Damien Miller7b10ef42002-01-21 23:44:12 +1100861#ifdef USE_SEED_FILES
862 prng_read_seedfile();
863#endif
864
Damien Miller32e48182002-04-14 19:27:12 +1000865 buf = xmalloc(bytes);
866
Damien Miller7b10ef42002-01-21 23:44:12 +1100867 /*
868 * Seed the RNG from wherever we can
869 */
Damien Miller787b2ec2003-11-21 23:56:47 +1100870
Damien Miller7b10ef42002-01-21 23:44:12 +1100871 /* Take whatever is on the stack, but don't credit it */
Damien Miller32e48182002-04-14 19:27:12 +1000872 RAND_add(buf, bytes, 0);
Damien Miller7b10ef42002-01-21 23:44:12 +1100873
Damien Millera8e06ce2003-11-21 23:48:55 +1100874 debug("Seeded RNG with %i bytes from system calls",
Damien Miller7b10ef42002-01-21 23:44:12 +1100875 (int)stir_from_system());
876
Darren Tucker8686ed72004-12-20 12:05:08 +1100877 /* try prngd, fall back to commands if prngd fails or not configured */
878 if (seed_from_prngd(buf, bytes) == 0) {
879 RAND_add(buf, bytes, bytes);
880 } else {
881 /* Read in collection commands */
882 if (prng_read_commands(SSH_PRNG_COMMAND_FILE) == -1)
883 fatal("PRNG initialisation failed -- exiting.");
884 debug("Seeded RNG with %i bytes from programs",
885 (int)stir_from_programs());
886 }
Damien Miller7b10ef42002-01-21 23:44:12 +1100887
888#ifdef USE_SEED_FILES
889 prng_write_seedfile();
890#endif
891
892 /*
893 * Write the seed to stdout
894 */
Damien Miller62116dc2001-12-24 01:41:47 +1100895
896 if (!RAND_status())
897 fatal("Not enough entropy in RNG");
898
Damien Millercafbcc72003-03-17 16:13:53 +1100899 if (RAND_bytes(buf, bytes) <= 0)
900 fatal("Couldn't extract entropy from PRNG");
Damien Miller62116dc2001-12-24 01:41:47 +1100901
Damien Miller32e48182002-04-14 19:27:12 +1000902 if (output_hex) {
903 for(ret = 0; ret < bytes; ret++)
904 printf("%02x", (unsigned char)(buf[ret]));
905 printf("\n");
906 } else
Darren Tucker8661b562003-07-06 15:20:46 +1000907 ret = atomicio(vwrite, STDOUT_FILENO, buf, bytes);
Damien Miller787b2ec2003-11-21 23:56:47 +1100908
Damien Miller32e48182002-04-14 19:27:12 +1000909 memset(buf, '\0', bytes);
910 xfree(buf);
Damien Miller787b2ec2003-11-21 23:56:47 +1100911
Damien Miller32e48182002-04-14 19:27:12 +1000912 return ret == bytes ? 0 : 1;
Damien Miller62116dc2001-12-24 01:41:47 +1100913}
Darren Tucker7b48d252005-02-16 13:20:07 +1100914
915/*
916 * We may attempt to re-seed during mkstemp if we are using the one in the
Darren Tucker7a8619a2005-02-16 13:32:30 +1100917 * compat library (via mkstemp -> _gettemp -> arc4random -> seed_rng) so we
918 * need our own seed_rng(). We must also check that we have enough entropy.
Darren Tucker7b48d252005-02-16 13:20:07 +1100919 */
920void
921seed_rng(void)
922{
923 if (!RAND_status())
924 fatal("Not enough entropy in RNG");
925}