1 /* $OpenBSD: moduli.c,v 1.26 2012/07/06 00:41:59 dtucker 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 */ 132 static u_int32_t *TinySieve, tinybits; 133 134 /* sieve 2**30 in 2**16 parts */ 135 static u_int32_t *SmallSieve, smallbits, smallbase; 136 137 /* sieve relative to the initial value */ 138 static u_int32_t *LargeSieve, largewords, largetries, largenumbers; 139 static u_int32_t largebits, largememory; /* megabytes */ 140 static BIGNUM *largebase; 141 142 int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *); 143 int 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 */ 149 static int 150 qfileout(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 */ 181 static void 182 sieve_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 */ 239 int 240 gen_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 xfree(LargeSieve); 437 xfree(SmallSieve); 438 xfree(TinySieve); 439 440 logit("%.24s Found %u candidates", ctime(&time_stop), r); 441 442 return (ret); 443 } 444 445 static void 446 write_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 } 474 475 static unsigned long 476 read_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 */ 497 int 498 prime_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 xfree(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