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-rw-r--r--ssh-rand-helper.c805
1 files changed, 805 insertions, 0 deletions
diff --git a/ssh-rand-helper.c b/ssh-rand-helper.c
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+++ b/ssh-rand-helper.c
@@ -0,0 +1,805 @@
1/*
2 * Copyright (c) 2001 Damien Miller. All rights reserved.
3 *
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
27#include <openssl/rand.h>
28#include <openssl/sha.h>
29#include <openssl/crypto.h>
30
31/* SunOS 4.4.4 needs this */
32#ifdef HAVE_FLOATINGPOINT_H
33# include <floatingpoint.h>
34#endif /* HAVE_FLOATINGPOINT_H */
35
36#include "misc.h"
37#include "xmalloc.h"
38#include "atomicio.h"
39#include "pathnames.h"
40#include "log.h"
41
42RCSID("$Id: ssh-rand-helper.c,v 1.1 2001/12/23 14:41:48 djm Exp $");
43
44#define RANDOM_SEED_SIZE 48
45
46#ifndef SSH_PRNG_SEED_FILE
47# define SSH_PRNG_SEED_FILE _PATH_SSH_USER_DIR"/prng_seed"
48#endif /* SSH_PRNG_SEED_FILE */
49#ifndef SSH_PRNG_COMMAND_FILE
50# define SSH_PRNG_COMMAND_FILE ETCDIR "/ssh_prng_cmds"
51#endif /* SSH_PRNG_COMMAND_FILE */
52
53
54#ifndef offsetof
55# define offsetof(type, member) ((size_t) &((type *)0)->member)
56#endif
57
58/* Number of times to pass through command list gathering entropy */
59#define NUM_ENTROPY_RUNS 1
60
61/* Scale entropy estimates back by this amount on subsequent runs */
62#define SCALE_PER_RUN 10.0
63
64/* Minimum number of commands to be considered valid */
65#define MIN_ENTROPY_SOURCES 16
66
67#define WHITESPACE " \t\n"
68
69#ifndef RUSAGE_SELF
70# define RUSAGE_SELF 0
71#endif
72#ifndef RUSAGE_CHILDREN
73# define RUSAGE_CHILDREN 0
74#endif
75
76#if defined(PRNGD_SOCKET) || defined(PRNGD_PORT)
77# define USE_PRNGD
78#endif
79
80#ifdef USE_PRNGD
81/* Collect entropy from PRNGD/EGD */
82int
83get_random_bytes(unsigned char *buf, int len)
84{
85 int fd;
86 char msg[2];
87#ifdef PRNGD_PORT
88 struct sockaddr_in addr;
89#else
90 struct sockaddr_un addr;
91#endif
92 int addr_len, rval, errors;
93 mysig_t old_sigpipe;
94
95 if (len > 255)
96 fatal("Too many bytes to read from PRNGD");
97
98 memset(&addr, '\0', sizeof(addr));
99
100#ifdef PRNGD_PORT
101 addr.sin_family = AF_INET;
102 addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
103 addr.sin_port = htons(PRNGD_PORT);
104 addr_len = sizeof(struct sockaddr_in);
105#else /* use IP socket PRNGD_SOCKET instead */
106 /* Sanity checks */
107 if (sizeof(PRNGD_SOCKET) > sizeof(addr.sun_path))
108 fatal("Random pool path is too long");
109
110 addr.sun_family = AF_UNIX;
111 strlcpy(addr.sun_path, PRNGD_SOCKET, sizeof(addr.sun_path));
112 addr_len = offsetof(struct sockaddr_un, sun_path) +
113 sizeof(PRNGD_SOCKET);
114#endif
115
116 old_sigpipe = mysignal(SIGPIPE, SIG_IGN);
117
118 errors = rval = 0;
119reopen:
120#ifdef PRNGD_PORT
121 fd = socket(addr.sin_family, SOCK_STREAM, 0);
122 if (fd == -1) {
123 error("Couldn't create AF_INET socket: %s", strerror(errno));
124 goto done;
125 }
126#else
127 fd = socket(addr.sun_family, SOCK_STREAM, 0);
128 if (fd == -1) {
129 error("Couldn't create AF_UNIX socket: %s", strerror(errno));
130 goto done;
131 }
132#endif
133
134 if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
135#ifdef PRNGD_PORT
136 error("Couldn't connect to PRNGD port %d: %s",
137 PRNGD_PORT, strerror(errno));
138#else
139 error("Couldn't connect to PRNGD socket \"%s\": %s",
140 addr.sun_path, strerror(errno));
141#endif
142 goto done;
143 }
144
145 /* Send blocking read request to PRNGD */
146 msg[0] = 0x02;
147 msg[1] = len;
148
149 if (atomicio(write, fd, msg, sizeof(msg)) != sizeof(msg)) {
150 if (errno == EPIPE && errors < 10) {
151 close(fd);
152 errors++;
153 goto reopen;
154 }
155 error("Couldn't write to PRNGD socket: %s",
156 strerror(errno));
157 goto done;
158 }
159
160 if (atomicio(read, fd, buf, len) != len) {
161 if (errno == EPIPE && errors < 10) {
162 close(fd);
163 errors++;
164 goto reopen;
165 }
166 error("Couldn't read from PRNGD socket: %s",
167 strerror(errno));
168 goto done;
169 }
170
171 rval = 1;
172done:
173 mysignal(SIGPIPE, old_sigpipe);
174 if (fd != -1)
175 close(fd);
176 return(rval);
177}
178
179static void
180seed_openssl_rng(void)
181{
182 unsigned char buf[RANDOM_SEED_SIZE];
183
184 if (!get_random_bytes(buf, sizeof(buf)))
185 fatal("Entropy collection failed");
186
187 RAND_add(buf, sizeof(buf), sizeof(buf));
188 memset(buf, '\0', sizeof(buf));
189}
190
191#else /* USE_PRNGD */
192
193/*
194 * FIXME: proper entropy estimations. All current values are guesses
195 * FIXME: (ATL) do estimates at compile time?
196 * FIXME: More entropy sources
197 */
198
199/* slow command timeouts (all in milliseconds) */
200/* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */
201static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC;
202
203typedef struct
204{
205 /* Proportion of data that is entropy */
206 double rate;
207 /* Counter goes positive if this command times out */
208 unsigned int badness;
209 /* Increases by factor of two each timeout */
210 unsigned int sticky_badness;
211 /* Path to executable */
212 char *path;
213 /* argv to pass to executable */
214 char *args[5];
215 /* full command string (debug) */
216 char *cmdstring;
217} entropy_source_t;
218
219double stir_from_system(void);
220double stir_from_programs(void);
221double stir_gettimeofday(double entropy_estimate);
222double stir_clock(double entropy_estimate);
223double stir_rusage(int who, double entropy_estimate);
224double hash_output_from_command(entropy_source_t *src, char *hash);
225
226/* this is initialised from a file, by prng_read_commands() */
227entropy_source_t *entropy_sources = NULL;
228
229double
230stir_from_system(void)
231{
232 double total_entropy_estimate;
233 long int i;
234
235 total_entropy_estimate = 0;
236
237 i = getpid();
238 RAND_add(&i, sizeof(i), 0.5);
239 total_entropy_estimate += 0.1;
240
241 i = getppid();
242 RAND_add(&i, sizeof(i), 0.5);
243 total_entropy_estimate += 0.1;
244
245 i = getuid();
246 RAND_add(&i, sizeof(i), 0.0);
247 i = getgid();
248 RAND_add(&i, sizeof(i), 0.0);
249
250 total_entropy_estimate += stir_gettimeofday(1.0);
251 total_entropy_estimate += stir_clock(0.5);
252 total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
253
254 return(total_entropy_estimate);
255}
256
257double
258stir_from_programs(void)
259{
260 int i;
261 int c;
262 double entropy_estimate;
263 double total_entropy_estimate;
264 char hash[SHA_DIGEST_LENGTH];
265
266 total_entropy_estimate = 0;
267 for(i = 0; i < NUM_ENTROPY_RUNS; i++) {
268 c = 0;
269 while (entropy_sources[c].path != NULL) {
270
271 if (!entropy_sources[c].badness) {
272 /* Hash output from command */
273 entropy_estimate = hash_output_from_command(&entropy_sources[c], hash);
274
275 /* Scale back entropy estimate according to command's rate */
276 entropy_estimate *= entropy_sources[c].rate;
277
278 /* Upper bound of entropy estimate is SHA_DIGEST_LENGTH */
279 if (entropy_estimate > SHA_DIGEST_LENGTH)
280 entropy_estimate = SHA_DIGEST_LENGTH;
281
282 /* Scale back estimates for subsequent passes through list */
283 entropy_estimate /= SCALE_PER_RUN * (i + 1.0);
284
285 /* Stir it in */
286 RAND_add(hash, sizeof(hash), entropy_estimate);
287
288 debug3("Got %0.2f bytes of entropy from '%s'", entropy_estimate,
289 entropy_sources[c].cmdstring);
290
291 total_entropy_estimate += entropy_estimate;
292
293 /* Execution times should be a little unpredictable */
294 total_entropy_estimate += stir_gettimeofday(0.05);
295 total_entropy_estimate += stir_clock(0.05);
296 total_entropy_estimate += stir_rusage(RUSAGE_SELF, 0.1);
297 total_entropy_estimate += stir_rusage(RUSAGE_CHILDREN, 0.1);
298 } else {
299 debug2("Command '%s' disabled (badness %d)",
300 entropy_sources[c].cmdstring, entropy_sources[c].badness);
301
302 if (entropy_sources[c].badness > 0)
303 entropy_sources[c].badness--;
304 }
305
306 c++;
307 }
308 }
309
310 return(total_entropy_estimate);
311}
312
313double
314stir_gettimeofday(double entropy_estimate)
315{
316 struct timeval tv;
317
318 if (gettimeofday(&tv, NULL) == -1)
319 fatal("Couldn't gettimeofday: %s", strerror(errno));
320
321 RAND_add(&tv, sizeof(tv), entropy_estimate);
322
323 return(entropy_estimate);
324}
325
326double
327stir_clock(double entropy_estimate)
328{
329#ifdef HAVE_CLOCK
330 clock_t c;
331
332 c = clock();
333 RAND_add(&c, sizeof(c), entropy_estimate);
334
335 return(entropy_estimate);
336#else /* _HAVE_CLOCK */
337 return(0);
338#endif /* _HAVE_CLOCK */
339}
340
341double
342stir_rusage(int who, double entropy_estimate)
343{
344#ifdef HAVE_GETRUSAGE
345 struct rusage ru;
346
347 if (getrusage(who, &ru) == -1)
348 return(0);
349
350 RAND_add(&ru, sizeof(ru), entropy_estimate);
351
352 return(entropy_estimate);
353#else /* _HAVE_GETRUSAGE */
354 return(0);
355#endif /* _HAVE_GETRUSAGE */
356}
357
358
359static int
360_get_timeval_msec_difference(struct timeval *t1, struct timeval *t2) {
361 int secdiff, usecdiff;
362
363 secdiff = t2->tv_sec - t1->tv_sec;
364 usecdiff = (secdiff*1000000) + (t2->tv_usec - t1->tv_usec);
365 return (int)(usecdiff / 1000);
366}
367
368double
369hash_output_from_command(entropy_source_t *src, char *hash)
370{
371 static int devnull = -1;
372 int p[2];
373 fd_set rdset;
374 int cmd_eof = 0, error_abort = 0;
375 struct timeval tv_start, tv_current;
376 int msec_elapsed = 0;
377 pid_t pid;
378 int status;
379 char buf[16384];
380 int bytes_read;
381 int total_bytes_read;
382 SHA_CTX sha;
383
384 debug3("Reading output from \'%s\'", src->cmdstring);
385
386 if (devnull == -1) {
387 devnull = open("/dev/null", O_RDWR);
388 if (devnull == -1)
389 fatal("Couldn't open /dev/null: %s", strerror(errno));
390 }
391
392 if (pipe(p) == -1)
393 fatal("Couldn't open pipe: %s", strerror(errno));
394
395 (void)gettimeofday(&tv_start, NULL); /* record start time */
396
397 switch (pid = fork()) {
398 case -1: /* Error */
399 close(p[0]);
400 close(p[1]);
401 fatal("Couldn't fork: %s", strerror(errno));
402 /* NOTREACHED */
403 case 0: /* Child */
404 dup2(devnull, STDIN_FILENO);
405 dup2(p[1], STDOUT_FILENO);
406 dup2(p[1], STDERR_FILENO);
407 close(p[0]);
408 close(p[1]);
409 close(devnull);
410
411 execv(src->path, (char**)(src->args));
412 debug("(child) Couldn't exec '%s': %s", src->cmdstring,
413 strerror(errno));
414 _exit(-1);
415 default: /* Parent */
416 break;
417 }
418
419 RAND_add(&pid, sizeof(&pid), 0.0);
420
421 close(p[1]);
422
423 /* Hash output from child */
424 SHA1_Init(&sha);
425 total_bytes_read = 0;
426
427 while (!error_abort && !cmd_eof) {
428 int ret;
429 struct timeval tv;
430 int msec_remaining;
431
432 (void) gettimeofday(&tv_current, 0);
433 msec_elapsed = _get_timeval_msec_difference(&tv_start, &tv_current);
434 if (msec_elapsed >= entropy_timeout_current) {
435 error_abort=1;
436 continue;
437 }
438 msec_remaining = entropy_timeout_current - msec_elapsed;
439
440 FD_ZERO(&rdset);
441 FD_SET(p[0], &rdset);
442 tv.tv_sec = msec_remaining / 1000;
443 tv.tv_usec = (msec_remaining % 1000) * 1000;
444
445 ret = select(p[0]+1, &rdset, NULL, NULL, &tv);
446
447 RAND_add(&tv, sizeof(tv), 0.0);
448
449 switch (ret) {
450 case 0:
451 /* timer expired */
452 error_abort = 1;
453 break;
454 case 1:
455 /* command input */
456 do {
457 bytes_read = read(p[0], buf, sizeof(buf));
458 } while (bytes_read == -1 && errno == EINTR);
459 RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
460 if (bytes_read == -1) {
461 error_abort = 1;
462 break;
463 } else if (bytes_read) {
464 SHA1_Update(&sha, buf, bytes_read);
465 total_bytes_read += bytes_read;
466 } else {
467 cmd_eof = 1;
468 }
469 break;
470 case -1:
471 default:
472 /* error */
473 debug("Command '%s': select() failed: %s", src->cmdstring,
474 strerror(errno));
475 error_abort = 1;
476 break;
477 }
478 }
479
480 SHA1_Final(hash, &sha);
481
482 close(p[0]);
483
484 debug3("Time elapsed: %d msec", msec_elapsed);
485
486 if (waitpid(pid, &status, 0) == -1) {
487 error("Couldn't wait for child '%s' completion: %s", src->cmdstring,
488 strerror(errno));
489 return(0.0);
490 }
491
492 RAND_add(&status, sizeof(&status), 0.0);
493
494 if (error_abort) {
495 /* closing p[0] on timeout causes the entropy command to
496 * SIGPIPE. Take whatever output we got, and mark this command
497 * as slow */
498 debug2("Command '%s' timed out", src->cmdstring);
499 src->sticky_badness *= 2;
500 src->badness = src->sticky_badness;
501 return(total_bytes_read);
502 }
503
504 if (WIFEXITED(status)) {
505 if (WEXITSTATUS(status)==0) {
506 return(total_bytes_read);
507 } else {
508 debug2("Command '%s' exit status was %d", src->cmdstring,
509 WEXITSTATUS(status));
510 src->badness = src->sticky_badness = 128;
511 return (0.0);
512 }
513 } else if (WIFSIGNALED(status)) {
514 debug2("Command '%s' returned on uncaught signal %d !", src->cmdstring,
515 status);
516 src->badness = src->sticky_badness = 128;
517 return(0.0);
518 } else
519 return(0.0);
520}
521
522/*
523 * prng seedfile functions
524 */
525int
526prng_check_seedfile(char *filename) {
527
528 struct stat st;
529
530 /* FIXME raceable: eg replace seed between this stat and subsequent open */
531 /* Not such a problem because we don't trust the seed file anyway */
532 if (lstat(filename, &st) == -1) {
533 /* Give up on hard errors */
534 if (errno != ENOENT)
535 debug("WARNING: Couldn't stat random seed file \"%s\": %s",
536 filename, strerror(errno));
537
538 return(0);
539 }
540
541 /* regular file? */
542 if (!S_ISREG(st.st_mode))
543 fatal("PRNG seedfile %.100s is not a regular file", filename);
544
545 /* mode 0600, owned by root or the current user? */
546 if (((st.st_mode & 0177) != 0) || !(st.st_uid == getuid())) {
547 debug("WARNING: PRNG seedfile %.100s must be mode 0600, owned by uid %d",
548 filename, getuid());
549 return(0);
550 }
551
552 return(1);
553}
554
555void
556prng_write_seedfile(void) {
557 int fd;
558 char seed[1024];
559 char filename[1024];
560 struct passwd *pw;
561
562 pw = getpwuid(getuid());
563 if (pw == NULL)
564 fatal("Couldn't get password entry for current user (%i): %s",
565 getuid(), strerror(errno));
566
567 /* Try to ensure that the parent directory is there */
568 snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
569 _PATH_SSH_USER_DIR);
570 mkdir(filename, 0700);
571
572 snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
573 SSH_PRNG_SEED_FILE);
574
575 debug("writing PRNG seed to file %.100s", filename);
576
577 RAND_bytes(seed, sizeof(seed));
578
579 /* Don't care if the seed doesn't exist */
580 prng_check_seedfile(filename);
581
582 if ((fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0600)) == -1) {
583 debug("WARNING: couldn't access PRNG seedfile %.100s (%.100s)",
584 filename, strerror(errno));
585 } else {
586 if (atomicio(write, fd, &seed, sizeof(seed)) != sizeof(seed))
587 fatal("problem writing PRNG seedfile %.100s (%.100s)", filename,
588 strerror(errno));
589 close(fd);
590 }
591}
592
593void
594prng_read_seedfile(void) {
595 int fd;
596 char seed[1024];
597 char filename[1024];
598 struct passwd *pw;
599
600 pw = getpwuid(getuid());
601 if (pw == NULL)
602 fatal("Couldn't get password entry for current user (%i): %s",
603 getuid(), strerror(errno));
604
605 snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
606 SSH_PRNG_SEED_FILE);
607
608 debug("loading PRNG seed from file %.100s", filename);
609
610 if (!prng_check_seedfile(filename)) {
611 verbose("Random seed file not found or not valid, ignoring.");
612 return;
613 }
614
615 /* open the file and read in the seed */
616 fd = open(filename, O_RDONLY);
617 if (fd == -1)
618 fatal("could not open PRNG seedfile %.100s (%.100s)", filename,
619 strerror(errno));
620
621 if (atomicio(read, fd, &seed, sizeof(seed)) != sizeof(seed)) {
622 verbose("invalid or short read from PRNG seedfile %.100s - ignoring",
623 filename);
624 memset(seed, '\0', sizeof(seed));
625 }
626 close(fd);
627
628 /* stir in the seed, with estimated entropy zero */
629 RAND_add(&seed, sizeof(seed), 0.0);
630}
631
632
633/*
634 * entropy command initialisation functions
635 */
636int
637prng_read_commands(char *cmdfilename)
638{
639 FILE *f;
640 char *cp;
641 char line[1024];
642 char cmd[1024];
643 char path[256];
644 int linenum;
645 int num_cmds = 64;
646 int cur_cmd = 0;
647 double est;
648 entropy_source_t *entcmd;
649
650 f = fopen(cmdfilename, "r");
651 if (!f) {
652 fatal("couldn't read entropy commands file %.100s: %.100s",
653 cmdfilename, strerror(errno));
654 }
655
656 entcmd = (entropy_source_t *)xmalloc(num_cmds * sizeof(entropy_source_t));
657 memset(entcmd, '\0', num_cmds * sizeof(entropy_source_t));
658
659 /* Read in file */
660 linenum = 0;
661 while (fgets(line, sizeof(line), f)) {
662 int arg;
663 char *argv;
664
665 linenum++;
666
667 /* skip leading whitespace, test for blank line or comment */
668 cp = line + strspn(line, WHITESPACE);
669 if ((*cp == 0) || (*cp == '#'))
670 continue; /* done with this line */
671
672 /* First non-whitespace char should be double quote delimiting */
673 /* commandline */
674 if (*cp != '"') {
675 error("bad entropy command, %.100s line %d", cmdfilename,
676 linenum);
677 continue;
678 }
679
680 /* first token, command args (incl. argv[0]) in double quotes */
681 cp = strtok(cp, "\"");
682 if (cp == NULL) {
683 error("missing or bad command string, %.100s line %d -- ignored",
684 cmdfilename, linenum);
685 continue;
686 }
687 strlcpy(cmd, cp, sizeof(cmd));
688
689 /* second token, full command path */
690 if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
691 error("missing command path, %.100s line %d -- ignored",
692 cmdfilename, linenum);
693 continue;
694 }
695
696 /* did configure mark this as dead? */
697 if (strncmp("undef", cp, 5) == 0)
698 continue;
699
700 strlcpy(path, cp, sizeof(path));
701
702 /* third token, entropy rate estimate for this command */
703 if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
704 error("missing entropy estimate, %.100s line %d -- ignored",
705 cmdfilename, linenum);
706 continue;
707 }
708 est = strtod(cp, &argv);
709
710 /* end of line */
711 if ((cp = strtok(NULL, WHITESPACE)) != NULL) {
712 error("garbage at end of line %d in %.100s -- ignored", linenum,
713 cmdfilename);
714 continue;
715 }
716
717 /* save the command for debug messages */
718 entcmd[cur_cmd].cmdstring = xstrdup(cmd);
719
720 /* split the command args */
721 cp = strtok(cmd, WHITESPACE);
722 arg = 0;
723 argv = NULL;
724 do {
725 char *s = (char*)xmalloc(strlen(cp) + 1);
726 strncpy(s, cp, strlen(cp) + 1);
727 entcmd[cur_cmd].args[arg] = s;
728 arg++;
729 } while ((arg < 5) && (cp = strtok(NULL, WHITESPACE)));
730
731 if (strtok(NULL, WHITESPACE))
732 error("ignored extra command elements (max 5), %.100s line %d",
733 cmdfilename, linenum);
734
735 /* Copy the command path and rate estimate */
736 entcmd[cur_cmd].path = xstrdup(path);
737 entcmd[cur_cmd].rate = est;
738
739 /* Initialise other values */
740 entcmd[cur_cmd].sticky_badness = 1;
741
742 cur_cmd++;
743
744 /* If we've filled the array, reallocate it twice the size */
745 /* Do this now because even if this we're on the last command,
746 we need another slot to mark the last entry */
747 if (cur_cmd == num_cmds) {
748 num_cmds *= 2;
749 entcmd = xrealloc(entcmd, num_cmds * sizeof(entropy_source_t));
750 }
751 }
752
753 /* zero the last entry */
754 memset(&entcmd[cur_cmd], '\0', sizeof(entropy_source_t));
755
756 /* trim to size */
757 entropy_sources = xrealloc(entcmd, (cur_cmd+1) * sizeof(entropy_source_t));
758
759 debug("Loaded %d entropy commands from %.100s", cur_cmd, cmdfilename);
760
761 return (cur_cmd >= MIN_ENTROPY_SOURCES);
762}
763
764static void
765seed_openssl_rng(void)
766{
767 /* Read in collection commands */
768 if (!prng_read_commands(SSH_PRNG_COMMAND_FILE))
769 fatal("PRNG initialisation failed -- exiting.");
770
771 prng_read_seedfile();
772
773 debug("Seeded RNG with %i bytes from programs",
774 (int)stir_from_programs());
775 debug("Seeded RNG with %i bytes from system calls",
776 (int)stir_from_system());
777
778 prng_write_seedfile();
779}
780
781#endif /* USE_PRNGD */
782
783int
784main(int argc, char **argv)
785{
786 unsigned char buf[48];
787 int ret;
788
789 /* XXX: need some debugging mode */
790 log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
791
792 seed_openssl_rng();
793
794 if (!RAND_status())
795 fatal("Not enough entropy in RNG");
796
797 RAND_bytes(buf, sizeof(buf));
798
799 ret = atomicio(write, STDOUT_FILENO, buf, sizeof(buf));
800
801 memset(buf, '\0', sizeof(buf));
802
803 return ret == sizeof(buf) ? 0 : 1;
804}
805
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 23:19:24 +0000