moduli.c revision 255767
1/* $OpenBSD: moduli.c,v 1.27 2013/05/17 00:13:13 djm Exp $ */
2/*
3 * Copyright 1994 Phil Karn <karn@qualcomm.com>
4 * Copyright 1996-1998, 2003 William Allen Simpson <wsimpson@greendragon.com>
5 * Copyright 2000 Niels Provos <provos@citi.umich.edu>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/*
30 * Two-step process to generate safe primes for DHGEX
31 *
32 *  Sieve candidates for "safe" primes,
33 *  suitable for use as Diffie-Hellman moduli;
34 *  that is, where q = (p-1)/2 is also prime.
35 *
36 * First step: generate candidate primes (memory intensive)
37 * Second step: test primes' safety (processor intensive)
38 */
39
40#include "includes.h"
41
42#include <sys/param.h>
43#include <sys/types.h>
44
45#include <openssl/bn.h>
46#include <openssl/dh.h>
47
48#include <errno.h>
49#include <stdio.h>
50#include <stdlib.h>
51#include <string.h>
52#include <stdarg.h>
53#include <time.h>
54#include <unistd.h>
55
56#include "xmalloc.h"
57#include "dh.h"
58#include "log.h"
59
60#include "openbsd-compat/openssl-compat.h"
61
62/*
63 * File output defines
64 */
65
66/* need line long enough for largest moduli plus headers */
67#define QLINESIZE		(100+8192)
68
69/*
70 * Size: decimal.
71 * Specifies the number of the most significant bit (0 to M).
72 * WARNING: internally, usually 1 to N.
73 */
74#define QSIZE_MINIMUM		(511)
75
76/*
77 * Prime sieving defines
78 */
79
80/* Constant: assuming 8 bit bytes and 32 bit words */
81#define SHIFT_BIT	(3)
82#define SHIFT_BYTE	(2)
83#define SHIFT_WORD	(SHIFT_BIT+SHIFT_BYTE)
84#define SHIFT_MEGABYTE	(20)
85#define SHIFT_MEGAWORD	(SHIFT_MEGABYTE-SHIFT_BYTE)
86
87/*
88 * Using virtual memory can cause thrashing.  This should be the largest
89 * number that is supported without a large amount of disk activity --
90 * that would increase the run time from hours to days or weeks!
91 */
92#define LARGE_MINIMUM	(8UL)	/* megabytes */
93
94/*
95 * Do not increase this number beyond the unsigned integer bit size.
96 * Due to a multiple of 4, it must be LESS than 128 (yielding 2**30 bits).
97 */
98#define LARGE_MAXIMUM	(127UL)	/* megabytes */
99
100/*
101 * Constant: when used with 32-bit integers, the largest sieve prime
102 * has to be less than 2**32.
103 */
104#define SMALL_MAXIMUM	(0xffffffffUL)
105
106/* Constant: can sieve all primes less than 2**32, as 65537**2 > 2**32-1. */
107#define TINY_NUMBER	(1UL<<16)
108
109/* Ensure enough bit space for testing 2*q. */
110#define TEST_MAXIMUM	(1UL<<16)
111#define TEST_MINIMUM	(QSIZE_MINIMUM + 1)
112/* real TEST_MINIMUM	(1UL << (SHIFT_WORD - TEST_POWER)) */
113#define TEST_POWER	(3)	/* 2**n, n < SHIFT_WORD */
114
115/* bit operations on 32-bit words */
116#define BIT_CLEAR(a,n)	((a)[(n)>>SHIFT_WORD] &= ~(1L << ((n) & 31)))
117#define BIT_SET(a,n)	((a)[(n)>>SHIFT_WORD] |= (1L << ((n) & 31)))
118#define BIT_TEST(a,n)	((a)[(n)>>SHIFT_WORD] & (1L << ((n) & 31)))
119
120/*
121 * Prime testing defines
122 */
123
124/* Minimum number of primality tests to perform */
125#define TRIAL_MINIMUM	(4)
126
127/*
128 * Sieving data (XXX - move to struct)
129 */
130
131/* sieve 2**16 */
132static u_int32_t *TinySieve, tinybits;
133
134/* sieve 2**30 in 2**16 parts */
135static u_int32_t *SmallSieve, smallbits, smallbase;
136
137/* sieve relative to the initial value */
138static u_int32_t *LargeSieve, largewords, largetries, largenumbers;
139static u_int32_t largebits, largememory;	/* megabytes */
140static BIGNUM *largebase;
141
142int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
143int prime_test(FILE *, FILE *, u_int32_t, u_int32_t, char *, unsigned long,
144    unsigned long);
145
146/*
147 * print moduli out in consistent form,
148 */
149static int
150qfileout(FILE * ofile, u_int32_t otype, u_int32_t otests, u_int32_t otries,
151    u_int32_t osize, u_int32_t ogenerator, BIGNUM * omodulus)
152{
153	struct tm *gtm;
154	time_t time_now;
155	int res;
156
157	time(&time_now);
158	gtm = gmtime(&time_now);
159
160	res = fprintf(ofile, "%04d%02d%02d%02d%02d%02d %u %u %u %u %x ",
161	    gtm->tm_year + 1900, gtm->tm_mon + 1, gtm->tm_mday,
162	    gtm->tm_hour, gtm->tm_min, gtm->tm_sec,
163	    otype, otests, otries, osize, ogenerator);
164
165	if (res < 0)
166		return (-1);
167
168	if (BN_print_fp(ofile, omodulus) < 1)
169		return (-1);
170
171	res = fprintf(ofile, "\n");
172	fflush(ofile);
173
174	return (res > 0 ? 0 : -1);
175}
176
177
178/*
179 ** Sieve p's and q's with small factors
180 */
181static void
182sieve_large(u_int32_t s)
183{
184	u_int32_t r, u;
185
186	debug3("sieve_large %u", s);
187	largetries++;
188	/* r = largebase mod s */
189	r = BN_mod_word(largebase, s);
190	if (r == 0)
191		u = 0; /* s divides into largebase exactly */
192	else
193		u = s - r; /* largebase+u is first entry divisible by s */
194
195	if (u < largebits * 2) {
196		/*
197		 * The sieve omits p's and q's divisible by 2, so ensure that
198		 * largebase+u is odd. Then, step through the sieve in
199		 * increments of 2*s
200		 */
201		if (u & 0x1)
202			u += s; /* Make largebase+u odd, and u even */
203
204		/* Mark all multiples of 2*s */
205		for (u /= 2; u < largebits; u += s)
206			BIT_SET(LargeSieve, u);
207	}
208
209	/* r = p mod s */
210	r = (2 * r + 1) % s;
211	if (r == 0)
212		u = 0; /* s divides p exactly */
213	else
214		u = s - r; /* p+u is first entry divisible by s */
215
216	if (u < largebits * 4) {
217		/*
218		 * The sieve omits p's divisible by 4, so ensure that
219		 * largebase+u is not. Then, step through the sieve in
220		 * increments of 4*s
221		 */
222		while (u & 0x3) {
223			if (SMALL_MAXIMUM - u < s)
224				return;
225			u += s;
226		}
227
228		/* Mark all multiples of 4*s */
229		for (u /= 4; u < largebits; u += s)
230			BIT_SET(LargeSieve, u);
231	}
232}
233
234/*
235 * list candidates for Sophie-Germain primes (where q = (p-1)/2)
236 * to standard output.
237 * The list is checked against small known primes (less than 2**30).
238 */
239int
240gen_candidates(FILE *out, u_int32_t memory, u_int32_t power, BIGNUM *start)
241{
242	BIGNUM *q;
243	u_int32_t j, r, s, t;
244	u_int32_t smallwords = TINY_NUMBER >> 6;
245	u_int32_t tinywords = TINY_NUMBER >> 6;
246	time_t time_start, time_stop;
247	u_int32_t i;
248	int ret = 0;
249
250	largememory = memory;
251
252	if (memory != 0 &&
253	    (memory < LARGE_MINIMUM || memory > LARGE_MAXIMUM)) {
254		error("Invalid memory amount (min %ld, max %ld)",
255		    LARGE_MINIMUM, LARGE_MAXIMUM);
256		return (-1);
257	}
258
259	/*
260	 * Set power to the length in bits of the prime to be generated.
261	 * This is changed to 1 less than the desired safe prime moduli p.
262	 */
263	if (power > TEST_MAXIMUM) {
264		error("Too many bits: %u > %lu", power, TEST_MAXIMUM);
265		return (-1);
266	} else if (power < TEST_MINIMUM) {
267		error("Too few bits: %u < %u", power, TEST_MINIMUM);
268		return (-1);
269	}
270	power--; /* decrement before squaring */
271
272	/*
273	 * The density of ordinary primes is on the order of 1/bits, so the
274	 * density of safe primes should be about (1/bits)**2. Set test range
275	 * to something well above bits**2 to be reasonably sure (but not
276	 * guaranteed) of catching at least one safe prime.
277	 */
278	largewords = ((power * power) >> (SHIFT_WORD - TEST_POWER));
279
280	/*
281	 * Need idea of how much memory is available. We don't have to use all
282	 * of it.
283	 */
284	if (largememory > LARGE_MAXIMUM) {
285		logit("Limited memory: %u MB; limit %lu MB",
286		    largememory, LARGE_MAXIMUM);
287		largememory = LARGE_MAXIMUM;
288	}
289
290	if (largewords <= (largememory << SHIFT_MEGAWORD)) {
291		logit("Increased memory: %u MB; need %u bytes",
292		    largememory, (largewords << SHIFT_BYTE));
293		largewords = (largememory << SHIFT_MEGAWORD);
294	} else if (largememory > 0) {
295		logit("Decreased memory: %u MB; want %u bytes",
296		    largememory, (largewords << SHIFT_BYTE));
297		largewords = (largememory << SHIFT_MEGAWORD);
298	}
299
300	TinySieve = xcalloc(tinywords, sizeof(u_int32_t));
301	tinybits = tinywords << SHIFT_WORD;
302
303	SmallSieve = xcalloc(smallwords, sizeof(u_int32_t));
304	smallbits = smallwords << SHIFT_WORD;
305
306	/*
307	 * dynamically determine available memory
308	 */
309	while ((LargeSieve = calloc(largewords, sizeof(u_int32_t))) == NULL)
310		largewords -= (1L << (SHIFT_MEGAWORD - 2)); /* 1/4 MB chunks */
311
312	largebits = largewords << SHIFT_WORD;
313	largenumbers = largebits * 2;	/* even numbers excluded */
314
315	/* validation check: count the number of primes tried */
316	largetries = 0;
317	if ((q = BN_new()) == NULL)
318		fatal("BN_new failed");
319
320	/*
321	 * Generate random starting point for subprime search, or use
322	 * specified parameter.
323	 */
324	if ((largebase = BN_new()) == NULL)
325		fatal("BN_new failed");
326	if (start == NULL) {
327		if (BN_rand(largebase, power, 1, 1) == 0)
328			fatal("BN_rand failed");
329	} else {
330		if (BN_copy(largebase, start) == NULL)
331			fatal("BN_copy: failed");
332	}
333
334	/* ensure odd */
335	if (BN_set_bit(largebase, 0) == 0)
336		fatal("BN_set_bit: failed");
337
338	time(&time_start);
339
340	logit("%.24s Sieve next %u plus %u-bit", ctime(&time_start),
341	    largenumbers, power);
342	debug2("start point: 0x%s", BN_bn2hex(largebase));
343
344	/*
345	 * TinySieve
346	 */
347	for (i = 0; i < tinybits; i++) {
348		if (BIT_TEST(TinySieve, i))
349			continue; /* 2*i+3 is composite */
350
351		/* The next tiny prime */
352		t = 2 * i + 3;
353
354		/* Mark all multiples of t */
355		for (j = i + t; j < tinybits; j += t)
356			BIT_SET(TinySieve, j);
357
358		sieve_large(t);
359	}
360
361	/*
362	 * Start the small block search at the next possible prime. To avoid
363	 * fencepost errors, the last pass is skipped.
364	 */
365	for (smallbase = TINY_NUMBER + 3;
366	    smallbase < (SMALL_MAXIMUM - TINY_NUMBER);
367	    smallbase += TINY_NUMBER) {
368		for (i = 0; i < tinybits; i++) {
369			if (BIT_TEST(TinySieve, i))
370				continue; /* 2*i+3 is composite */
371
372			/* The next tiny prime */
373			t = 2 * i + 3;
374			r = smallbase % t;
375
376			if (r == 0) {
377				s = 0; /* t divides into smallbase exactly */
378			} else {
379				/* smallbase+s is first entry divisible by t */
380				s = t - r;
381			}
382
383			/*
384			 * The sieve omits even numbers, so ensure that
385			 * smallbase+s is odd. Then, step through the sieve
386			 * in increments of 2*t
387			 */
388			if (s & 1)
389				s += t; /* Make smallbase+s odd, and s even */
390
391			/* Mark all multiples of 2*t */
392			for (s /= 2; s < smallbits; s += t)
393				BIT_SET(SmallSieve, s);
394		}
395
396		/*
397		 * SmallSieve
398		 */
399		for (i = 0; i < smallbits; i++) {
400			if (BIT_TEST(SmallSieve, i))
401				continue; /* 2*i+smallbase is composite */
402
403			/* The next small prime */
404			sieve_large((2 * i) + smallbase);
405		}
406
407		memset(SmallSieve, 0, smallwords << SHIFT_BYTE);
408	}
409
410	time(&time_stop);
411
412	logit("%.24s Sieved with %u small primes in %ld seconds",
413	    ctime(&time_stop), largetries, (long) (time_stop - time_start));
414
415	for (j = r = 0; j < largebits; j++) {
416		if (BIT_TEST(LargeSieve, j))
417			continue; /* Definitely composite, skip */
418
419		debug2("test q = largebase+%u", 2 * j);
420		if (BN_set_word(q, 2 * j) == 0)
421			fatal("BN_set_word failed");
422		if (BN_add(q, q, largebase) == 0)
423			fatal("BN_add failed");
424		if (qfileout(out, MODULI_TYPE_SOPHIE_GERMAIN,
425		    MODULI_TESTS_SIEVE, largetries,
426		    (power - 1) /* MSB */, (0), q) == -1) {
427			ret = -1;
428			break;
429		}
430
431		r++; /* count q */
432	}
433
434	time(&time_stop);
435
436	free(LargeSieve);
437	free(SmallSieve);
438	free(TinySieve);
439
440	logit("%.24s Found %u candidates", ctime(&time_stop), r);
441
442	return (ret);
443}
444
445static void
446write_checkpoint(char *cpfile, u_int32_t lineno)
447{
448	FILE *fp;
449	char tmp[MAXPATHLEN];
450	int r;
451
452	r = snprintf(tmp, sizeof(tmp), "%s.XXXXXXXXXX", cpfile);
453	if (r == -1 || r >= MAXPATHLEN) {
454		logit("write_checkpoint: temp pathname too long");
455		return;
456	}
457	if ((r = mkstemp(tmp)) == -1) {
458		logit("mkstemp(%s): %s", tmp, strerror(errno));
459		return;
460	}
461	if ((fp = fdopen(r, "w")) == NULL) {
462		logit("write_checkpoint: fdopen: %s", strerror(errno));
463		close(r);
464		return;
465	}
466	if (fprintf(fp, "%lu\n", (unsigned long)lineno) > 0 && fclose(fp) == 0
467	    && rename(tmp, cpfile) == 0)
468		debug3("wrote checkpoint line %lu to '%s'",
469		    (unsigned long)lineno, cpfile);
470	else
471		logit("failed to write to checkpoint file '%s': %s", cpfile,
472		    strerror(errno));
473}
474
475static unsigned long
476read_checkpoint(char *cpfile)
477{
478	FILE *fp;
479	unsigned long lineno = 0;
480
481	if ((fp = fopen(cpfile, "r")) == NULL)
482		return 0;
483	if (fscanf(fp, "%lu\n", &lineno) < 1)
484		logit("Failed to load checkpoint from '%s'", cpfile);
485	else
486		logit("Loaded checkpoint from '%s' line %lu", cpfile, lineno);
487	fclose(fp);
488	return lineno;
489}
490
491/*
492 * perform a Miller-Rabin primality test
493 * on the list of candidates
494 * (checking both q and p)
495 * The result is a list of so-call "safe" primes
496 */
497int
498prime_test(FILE *in, FILE *out, u_int32_t trials, u_int32_t generator_wanted,
499    char *checkpoint_file, unsigned long start_lineno, unsigned long num_lines)
500{
501	BIGNUM *q, *p, *a;
502	BN_CTX *ctx;
503	char *cp, *lp;
504	u_int32_t count_in = 0, count_out = 0, count_possible = 0;
505	u_int32_t generator_known, in_tests, in_tries, in_type, in_size;
506	unsigned long last_processed = 0, end_lineno;
507	time_t time_start, time_stop;
508	int res;
509
510	if (trials < TRIAL_MINIMUM) {
511		error("Minimum primality trials is %d", TRIAL_MINIMUM);
512		return (-1);
513	}
514
515	time(&time_start);
516
517	if ((p = BN_new()) == NULL)
518		fatal("BN_new failed");
519	if ((q = BN_new()) == NULL)
520		fatal("BN_new failed");
521	if ((ctx = BN_CTX_new()) == NULL)
522		fatal("BN_CTX_new failed");
523
524	debug2("%.24s Final %u Miller-Rabin trials (%x generator)",
525	    ctime(&time_start), trials, generator_wanted);
526
527	if (checkpoint_file != NULL)
528		last_processed = read_checkpoint(checkpoint_file);
529	if (start_lineno > last_processed)
530		last_processed = start_lineno;
531	if (num_lines == 0)
532		end_lineno = ULONG_MAX;
533	else
534		end_lineno = last_processed + num_lines;
535	debug2("process line %lu to line %lu", last_processed, end_lineno);
536
537	res = 0;
538	lp = xmalloc(QLINESIZE + 1);
539	while (fgets(lp, QLINESIZE + 1, in) != NULL && count_in < end_lineno) {
540		count_in++;
541		if (checkpoint_file != NULL) {
542			if (count_in <= last_processed) {
543				debug3("skipping line %u, before checkpoint",
544				    count_in);
545				continue;
546			}
547			write_checkpoint(checkpoint_file, count_in);
548		}
549		if (strlen(lp) < 14 || *lp == '!' || *lp == '#') {
550			debug2("%10u: comment or short line", count_in);
551			continue;
552		}
553
554		/* XXX - fragile parser */
555		/* time */
556		cp = &lp[14];	/* (skip) */
557
558		/* type */
559		in_type = strtoul(cp, &cp, 10);
560
561		/* tests */
562		in_tests = strtoul(cp, &cp, 10);
563
564		if (in_tests & MODULI_TESTS_COMPOSITE) {
565			debug2("%10u: known composite", count_in);
566			continue;
567		}
568
569		/* tries */
570		in_tries = strtoul(cp, &cp, 10);
571
572		/* size (most significant bit) */
573		in_size = strtoul(cp, &cp, 10);
574
575		/* generator (hex) */
576		generator_known = strtoul(cp, &cp, 16);
577
578		/* Skip white space */
579		cp += strspn(cp, " ");
580
581		/* modulus (hex) */
582		switch (in_type) {
583		case MODULI_TYPE_SOPHIE_GERMAIN:
584			debug2("%10u: (%u) Sophie-Germain", count_in, in_type);
585			a = q;
586			if (BN_hex2bn(&a, cp) == 0)
587				fatal("BN_hex2bn failed");
588			/* p = 2*q + 1 */
589			if (BN_lshift(p, q, 1) == 0)
590				fatal("BN_lshift failed");
591			if (BN_add_word(p, 1) == 0)
592				fatal("BN_add_word failed");
593			in_size += 1;
594			generator_known = 0;
595			break;
596		case MODULI_TYPE_UNSTRUCTURED:
597		case MODULI_TYPE_SAFE:
598		case MODULI_TYPE_SCHNORR:
599		case MODULI_TYPE_STRONG:
600		case MODULI_TYPE_UNKNOWN:
601			debug2("%10u: (%u)", count_in, in_type);
602			a = p;
603			if (BN_hex2bn(&a, cp) == 0)
604				fatal("BN_hex2bn failed");
605			/* q = (p-1) / 2 */
606			if (BN_rshift(q, p, 1) == 0)
607				fatal("BN_rshift failed");
608			break;
609		default:
610			debug2("Unknown prime type");
611			break;
612		}
613
614		/*
615		 * due to earlier inconsistencies in interpretation, check
616		 * the proposed bit size.
617		 */
618		if ((u_int32_t)BN_num_bits(p) != (in_size + 1)) {
619			debug2("%10u: bit size %u mismatch", count_in, in_size);
620			continue;
621		}
622		if (in_size < QSIZE_MINIMUM) {
623			debug2("%10u: bit size %u too short", count_in, in_size);
624			continue;
625		}
626
627		if (in_tests & MODULI_TESTS_MILLER_RABIN)
628			in_tries += trials;
629		else
630			in_tries = trials;
631
632		/*
633		 * guess unknown generator
634		 */
635		if (generator_known == 0) {
636			if (BN_mod_word(p, 24) == 11)
637				generator_known = 2;
638			else if (BN_mod_word(p, 12) == 5)
639				generator_known = 3;
640			else {
641				u_int32_t r = BN_mod_word(p, 10);
642
643				if (r == 3 || r == 7)
644					generator_known = 5;
645			}
646		}
647		/*
648		 * skip tests when desired generator doesn't match
649		 */
650		if (generator_wanted > 0 &&
651		    generator_wanted != generator_known) {
652			debug2("%10u: generator %d != %d",
653			    count_in, generator_known, generator_wanted);
654			continue;
655		}
656
657		/*
658		 * Primes with no known generator are useless for DH, so
659		 * skip those.
660		 */
661		if (generator_known == 0) {
662			debug2("%10u: no known generator", count_in);
663			continue;
664		}
665
666		count_possible++;
667
668		/*
669		 * The (1/4)^N performance bound on Miller-Rabin is
670		 * extremely pessimistic, so don't spend a lot of time
671		 * really verifying that q is prime until after we know
672		 * that p is also prime. A single pass will weed out the
673		 * vast majority of composite q's.
674		 */
675		if (BN_is_prime_ex(q, 1, ctx, NULL) <= 0) {
676			debug("%10u: q failed first possible prime test",
677			    count_in);
678			continue;
679		}
680
681		/*
682		 * q is possibly prime, so go ahead and really make sure
683		 * that p is prime. If it is, then we can go back and do
684		 * the same for q. If p is composite, chances are that
685		 * will show up on the first Rabin-Miller iteration so it
686		 * doesn't hurt to specify a high iteration count.
687		 */
688		if (!BN_is_prime_ex(p, trials, ctx, NULL)) {
689			debug("%10u: p is not prime", count_in);
690			continue;
691		}
692		debug("%10u: p is almost certainly prime", count_in);
693
694		/* recheck q more rigorously */
695		if (!BN_is_prime_ex(q, trials - 1, ctx, NULL)) {
696			debug("%10u: q is not prime", count_in);
697			continue;
698		}
699		debug("%10u: q is almost certainly prime", count_in);
700
701		if (qfileout(out, MODULI_TYPE_SAFE,
702		    in_tests | MODULI_TESTS_MILLER_RABIN,
703		    in_tries, in_size, generator_known, p)) {
704			res = -1;
705			break;
706		}
707
708		count_out++;
709	}
710
711	time(&time_stop);
712	free(lp);
713	BN_free(p);
714	BN_free(q);
715	BN_CTX_free(ctx);
716
717	if (checkpoint_file != NULL)
718		unlink(checkpoint_file);
719
720	logit("%.24s Found %u safe primes of %u candidates in %ld seconds",
721	    ctime(&time_stop), count_out, count_possible,
722	    (long) (time_stop - time_start));
723
724	return (res);
725}
726