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Commit | Line | Data |
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4f22f405 RS |
1 | /* |
2 | * WARNING: do not edit! | |
3 | * Generated by crypto/bn/bn_prime.pl | |
4 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. | |
5 | * | |
6 | * Licensed under the OpenSSL license (the "License"). You may not use | |
7 | * this file except in compliance with the License. You can obtain a copy | |
8 | * in the file LICENSE in the source distribution or at | |
9 | * https://www.openssl.org/source/license.html | |
bfe30e4d | 10 | */ |
d02b48c6 RE |
11 | |
12 | #include <stdio.h> | |
13 | #include <time.h> | |
b39fc560 | 14 | #include "internal/cryptlib.h" |
d02b48c6 | 15 | #include "bn_lcl.h" |
ec577822 | 16 | #include <openssl/rand.h> |
d02b48c6 | 17 | |
0f113f3e MC |
18 | /* |
19 | * The quick sieve algorithm approach to weeding out primes is Philip | |
20 | * Zimmermann's, as implemented in PGP. I have had a read of his comments | |
21 | * and implemented my own version. | |
d02b48c6 RE |
22 | */ |
23 | #include "bn_prime.h" | |
24 | ||
7999c65c | 25 | static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, |
0f113f3e MC |
26 | const BIGNUM *a1_odd, int k, BN_CTX *ctx, |
27 | BN_MONT_CTX *mont); | |
8e704858 | 28 | static int probable_prime(BIGNUM *rnd, int bits, prime_t *mods); |
76aa0ddc | 29 | static int probable_prime_dh_safe(BIGNUM *rnd, int bits, |
0f113f3e MC |
30 | const BIGNUM *add, const BIGNUM *rem, |
31 | BN_CTX *ctx); | |
eb952088 | 32 | |
46838817 | 33 | static const int prime_offsets[480] = { |
0f113f3e MC |
34 | 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, |
35 | 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, | |
36 | 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 221, 223, 227, 229, | |
37 | 233, 239, 241, 247, 251, 257, 263, 269, 271, 277, 281, 283, 289, 293, | |
38 | 299, 307, 311, 313, 317, 323, 331, 337, 347, 349, 353, 359, 361, 367, | |
39 | 373, 377, 379, 383, 389, 391, 397, 401, 403, 409, 419, 421, 431, 433, | |
40 | 437, 439, 443, 449, 457, 461, 463, 467, 479, 481, 487, 491, 493, 499, | |
41 | 503, 509, 521, 523, 527, 529, 533, 541, 547, 551, 557, 559, 563, 569, | |
42 | 571, 577, 587, 589, 593, 599, 601, 607, 611, 613, 617, 619, 629, 631, | |
43 | 641, 643, 647, 653, 659, 661, 667, 673, 677, 683, 689, 691, 697, 701, | |
44 | 703, 709, 713, 719, 727, 731, 733, 739, 743, 751, 757, 761, 767, 769, | |
45 | 773, 779, 787, 793, 797, 799, 809, 811, 817, 821, 823, 827, 829, 839, | |
46 | 841, 851, 853, 857, 859, 863, 871, 877, 881, 883, 887, 893, 899, 901, | |
47 | 907, 911, 919, 923, 929, 937, 941, 943, 947, 949, 953, 961, 967, 971, | |
48 | 977, 983, 989, 991, 997, 1003, 1007, 1009, 1013, 1019, 1021, 1027, 1031, | |
49 | 1033, 1037, 1039, 1049, 1051, 1061, 1063, 1069, 1073, 1079, 1081, 1087, | |
50 | 1091, 1093, 1097, 1103, 1109, 1117, 1121, 1123, 1129, 1139, 1147, 1151, | |
51 | 1153, 1157, 1159, 1163, 1171, 1181, 1187, 1189, 1193, 1201, 1207, 1213, | |
52 | 1217, 1219, 1223, 1229, 1231, 1237, 1241, 1247, 1249, 1259, 1261, 1271, | |
53 | 1273, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1313, 1319, | |
54 | 1321, 1327, 1333, 1339, 1343, 1349, 1357, 1361, 1363, 1367, 1369, 1373, | |
55 | 1381, 1387, 1391, 1399, 1403, 1409, 1411, 1417, 1423, 1427, 1429, 1433, | |
56 | 1439, 1447, 1451, 1453, 1457, 1459, 1469, 1471, 1481, 1483, 1487, 1489, | |
57 | 1493, 1499, 1501, 1511, 1513, 1517, 1523, 1531, 1537, 1541, 1543, 1549, | |
58 | 1553, 1559, 1567, 1571, 1577, 1579, 1583, 1591, 1597, 1601, 1607, 1609, | |
59 | 1613, 1619, 1621, 1627, 1633, 1637, 1643, 1649, 1651, 1657, 1663, 1667, | |
60 | 1669, 1679, 1681, 1691, 1693, 1697, 1699, 1703, 1709, 1711, 1717, 1721, | |
61 | 1723, 1733, 1739, 1741, 1747, 1751, 1753, 1759, 1763, 1769, 1777, 1781, | |
62 | 1783, 1787, 1789, 1801, 1807, 1811, 1817, 1819, 1823, 1829, 1831, 1843, | |
63 | 1847, 1849, 1853, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1891, 1901, | |
64 | 1907, 1909, 1913, 1919, 1921, 1927, 1931, 1933, 1937, 1943, 1949, 1951, | |
65 | 1957, 1961, 1963, 1973, 1979, 1987, 1993, 1997, 1999, 2003, 2011, 2017, | |
66 | 2021, 2027, 2029, 2033, 2039, 2041, 2047, 2053, 2059, 2063, 2069, 2071, | |
67 | 2077, 2081, 2083, 2087, 2089, 2099, 2111, 2113, 2117, 2119, 2129, 2131, | |
68 | 2137, 2141, 2143, 2147, 2153, 2159, 2161, 2171, 2173, 2179, 2183, 2197, | |
69 | 2201, 2203, 2207, 2209, 2213, 2221, 2227, 2231, 2237, 2239, 2243, 2249, | |
70 | 2251, 2257, 2263, 2267, 2269, 2273, 2279, 2281, 2287, 2291, 2293, 2297, | |
71 | 2309, 2311 | |
72 | }; | |
73 | ||
46838817 BL |
74 | static const int prime_offset_count = 480; |
75 | static const int prime_multiplier = 2310; | |
0f113f3e MC |
76 | static const int prime_multiplier_bits = 11; /* 2^|prime_multiplier_bits| <= |
77 | * |prime_multiplier| */ | |
46838817 | 78 | static const int first_prime_index = 5; |
b0513819 | 79 | |
e9224c71 | 80 | int BN_GENCB_call(BN_GENCB *cb, int a, int b) |
0f113f3e MC |
81 | { |
82 | /* No callback means continue */ | |
83 | if (!cb) | |
84 | return 1; | |
85 | switch (cb->ver) { | |
86 | case 1: | |
87 | /* Deprecated-style callbacks */ | |
88 | if (!cb->cb.cb_1) | |
89 | return 1; | |
90 | cb->cb.cb_1(a, b, cb->arg); | |
91 | return 1; | |
92 | case 2: | |
93 | /* New-style callbacks */ | |
94 | return cb->cb.cb_2(a, b, cb); | |
95 | default: | |
96 | break; | |
97 | } | |
98 | /* Unrecognised callback type */ | |
99 | return 0; | |
100 | } | |
e9224c71 GT |
101 | |
102 | int BN_generate_prime_ex(BIGNUM *ret, int bits, int safe, | |
0f113f3e MC |
103 | const BIGNUM *add, const BIGNUM *rem, BN_GENCB *cb) |
104 | { | |
105 | BIGNUM *t; | |
106 | int found = 0; | |
107 | int i, j, c1 = 0; | |
8e704858 RS |
108 | BN_CTX *ctx = NULL; |
109 | prime_t *mods = NULL; | |
0f113f3e MC |
110 | int checks = BN_prime_checks_for_size(bits); |
111 | ||
112 | if (bits < 2) { | |
113 | /* There are no prime numbers this small. */ | |
114 | BNerr(BN_F_BN_GENERATE_PRIME_EX, BN_R_BITS_TOO_SMALL); | |
115 | return 0; | |
116 | } else if (bits == 2 && safe) { | |
117 | /* The smallest safe prime (7) is three bits. */ | |
118 | BNerr(BN_F_BN_GENERATE_PRIME_EX, BN_R_BITS_TOO_SMALL); | |
119 | return 0; | |
120 | } | |
121 | ||
d71eb667 MC |
122 | mods = OPENSSL_zalloc(sizeof(*mods) * NUMPRIMES); |
123 | if (mods == NULL) | |
124 | goto err; | |
125 | ||
0f113f3e MC |
126 | ctx = BN_CTX_new(); |
127 | if (ctx == NULL) | |
128 | goto err; | |
129 | BN_CTX_start(ctx); | |
130 | t = BN_CTX_get(ctx); | |
131 | if (!t) | |
132 | goto err; | |
133 | loop: | |
134 | /* make a random number and set the top and bottom bits */ | |
135 | if (add == NULL) { | |
8e704858 | 136 | if (!probable_prime(ret, bits, mods)) |
0f113f3e MC |
137 | goto err; |
138 | } else { | |
139 | if (safe) { | |
140 | if (!probable_prime_dh_safe(ret, bits, add, rem, ctx)) | |
141 | goto err; | |
142 | } else { | |
143 | if (!bn_probable_prime_dh(ret, bits, add, rem, ctx)) | |
144 | goto err; | |
145 | } | |
146 | } | |
147 | /* if (BN_mod_word(ret,(BN_ULONG)3) == 1) goto loop; */ | |
148 | if (!BN_GENCB_call(cb, 0, c1++)) | |
149 | /* aborted */ | |
150 | goto err; | |
151 | ||
152 | if (!safe) { | |
153 | i = BN_is_prime_fasttest_ex(ret, checks, ctx, 0, cb); | |
154 | if (i == -1) | |
155 | goto err; | |
156 | if (i == 0) | |
157 | goto loop; | |
158 | } else { | |
159 | /* | |
160 | * for "safe prime" generation, check that (p-1)/2 is prime. Since a | |
161 | * prime is odd, We just need to divide by 2 | |
162 | */ | |
163 | if (!BN_rshift1(t, ret)) | |
164 | goto err; | |
165 | ||
166 | for (i = 0; i < checks; i++) { | |
167 | j = BN_is_prime_fasttest_ex(ret, 1, ctx, 0, cb); | |
168 | if (j == -1) | |
169 | goto err; | |
170 | if (j == 0) | |
171 | goto loop; | |
172 | ||
173 | j = BN_is_prime_fasttest_ex(t, 1, ctx, 0, cb); | |
174 | if (j == -1) | |
175 | goto err; | |
176 | if (j == 0) | |
177 | goto loop; | |
178 | ||
179 | if (!BN_GENCB_call(cb, 2, c1 - 1)) | |
180 | goto err; | |
181 | /* We have a safe prime test pass */ | |
182 | } | |
183 | } | |
184 | /* we have a prime :-) */ | |
185 | found = 1; | |
186 | err: | |
8e704858 | 187 | OPENSSL_free(mods); |
23a1d5e9 | 188 | if (ctx != NULL) |
0f113f3e | 189 | BN_CTX_end(ctx); |
23a1d5e9 | 190 | BN_CTX_free(ctx); |
0f113f3e MC |
191 | bn_check_top(ret); |
192 | return found; | |
193 | } | |
194 | ||
195 | int BN_is_prime_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, | |
196 | BN_GENCB *cb) | |
197 | { | |
198 | return BN_is_prime_fasttest_ex(a, checks, ctx_passed, 0, cb); | |
199 | } | |
e74231ed | 200 | |
e9224c71 | 201 | int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed, |
0f113f3e MC |
202 | int do_trial_division, BN_GENCB *cb) |
203 | { | |
204 | int i, j, ret = -1; | |
205 | int k; | |
206 | BN_CTX *ctx = NULL; | |
207 | BIGNUM *A1, *A1_odd, *check; /* taken from ctx */ | |
208 | BN_MONT_CTX *mont = NULL; | |
209 | const BIGNUM *A = NULL; | |
210 | ||
211 | if (BN_cmp(a, BN_value_one()) <= 0) | |
212 | return 0; | |
213 | ||
214 | if (checks == BN_prime_checks) | |
215 | checks = BN_prime_checks_for_size(BN_num_bits(a)); | |
216 | ||
217 | /* first look for small factors */ | |
218 | if (!BN_is_odd(a)) | |
219 | /* a is even => a is prime if and only if a == 2 */ | |
220 | return BN_is_word(a, 2); | |
221 | if (do_trial_division) { | |
222 | for (i = 1; i < NUMPRIMES; i++) | |
223 | if (BN_mod_word(a, primes[i]) == 0) | |
224 | return 0; | |
225 | if (!BN_GENCB_call(cb, 1, -1)) | |
226 | goto err; | |
227 | } | |
228 | ||
229 | if (ctx_passed != NULL) | |
230 | ctx = ctx_passed; | |
231 | else if ((ctx = BN_CTX_new()) == NULL) | |
232 | goto err; | |
233 | BN_CTX_start(ctx); | |
234 | ||
235 | /* A := abs(a) */ | |
236 | if (a->neg) { | |
237 | BIGNUM *t; | |
238 | if ((t = BN_CTX_get(ctx)) == NULL) | |
239 | goto err; | |
240 | BN_copy(t, a); | |
241 | t->neg = 0; | |
242 | A = t; | |
243 | } else | |
244 | A = a; | |
245 | A1 = BN_CTX_get(ctx); | |
246 | A1_odd = BN_CTX_get(ctx); | |
247 | check = BN_CTX_get(ctx); | |
248 | if (check == NULL) | |
249 | goto err; | |
250 | ||
251 | /* compute A1 := A - 1 */ | |
252 | if (!BN_copy(A1, A)) | |
253 | goto err; | |
254 | if (!BN_sub_word(A1, 1)) | |
255 | goto err; | |
256 | if (BN_is_zero(A1)) { | |
257 | ret = 0; | |
258 | goto err; | |
259 | } | |
260 | ||
261 | /* write A1 as A1_odd * 2^k */ | |
262 | k = 1; | |
263 | while (!BN_is_bit_set(A1, k)) | |
264 | k++; | |
265 | if (!BN_rshift(A1_odd, A1, k)) | |
266 | goto err; | |
267 | ||
268 | /* Montgomery setup for computations mod A */ | |
269 | mont = BN_MONT_CTX_new(); | |
270 | if (mont == NULL) | |
271 | goto err; | |
272 | if (!BN_MONT_CTX_set(mont, A, ctx)) | |
273 | goto err; | |
274 | ||
275 | for (i = 0; i < checks; i++) { | |
276 | if (!BN_pseudo_rand_range(check, A1)) | |
277 | goto err; | |
278 | if (!BN_add_word(check, 1)) | |
279 | goto err; | |
280 | /* now 1 <= check < A */ | |
281 | ||
282 | j = witness(check, A, A1, A1_odd, k, ctx, mont); | |
283 | if (j == -1) | |
284 | goto err; | |
285 | if (j) { | |
286 | ret = 0; | |
287 | goto err; | |
288 | } | |
289 | if (!BN_GENCB_call(cb, 1, i)) | |
290 | goto err; | |
291 | } | |
292 | ret = 1; | |
293 | err: | |
294 | if (ctx != NULL) { | |
295 | BN_CTX_end(ctx); | |
296 | if (ctx_passed == NULL) | |
297 | BN_CTX_free(ctx); | |
298 | } | |
23a1d5e9 | 299 | BN_MONT_CTX_free(mont); |
0f113f3e MC |
300 | |
301 | return (ret); | |
302 | } | |
a87030a1 | 303 | |
982c42cb | 304 | int bn_probable_prime_dh_retry(BIGNUM *rnd, int bits, BN_CTX *ctx) |
0f113f3e MC |
305 | { |
306 | int i; | |
307 | int ret = 0; | |
308 | ||
309 | loop: | |
310 | if (!BN_rand(rnd, bits, 0, 1)) | |
311 | goto err; | |
312 | ||
313 | /* we now have a random number 'rand' to test. */ | |
314 | ||
315 | for (i = 1; i < NUMPRIMES; i++) { | |
316 | /* check that rnd is a prime */ | |
317 | if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1) { | |
318 | goto loop; | |
319 | } | |
320 | } | |
321 | ret = 1; | |
322 | ||
323 | err: | |
324 | bn_check_top(rnd); | |
325 | return (ret); | |
326 | } | |
982c42cb FLM |
327 | |
328 | int bn_probable_prime_dh_coprime(BIGNUM *rnd, int bits, BN_CTX *ctx) | |
0f113f3e MC |
329 | { |
330 | int i; | |
331 | BIGNUM *offset_index; | |
332 | BIGNUM *offset_count; | |
333 | int ret = 0; | |
334 | ||
335 | OPENSSL_assert(bits > prime_multiplier_bits); | |
336 | ||
337 | BN_CTX_start(ctx); | |
338 | if ((offset_index = BN_CTX_get(ctx)) == NULL) | |
339 | goto err; | |
340 | if ((offset_count = BN_CTX_get(ctx)) == NULL) | |
341 | goto err; | |
342 | ||
343 | BN_add_word(offset_count, prime_offset_count); | |
344 | ||
345 | loop: | |
346 | if (!BN_rand(rnd, bits - prime_multiplier_bits, 0, 1)) | |
347 | goto err; | |
348 | if (BN_is_bit_set(rnd, bits)) | |
349 | goto loop; | |
350 | if (!BN_rand_range(offset_index, offset_count)) | |
351 | goto err; | |
352 | ||
353 | BN_mul_word(rnd, prime_multiplier); | |
354 | BN_add_word(rnd, prime_offsets[BN_get_word(offset_index)]); | |
355 | ||
356 | /* we now have a random number 'rand' to test. */ | |
357 | ||
358 | /* skip coprimes */ | |
359 | for (i = first_prime_index; i < NUMPRIMES; i++) { | |
360 | /* check that rnd is a prime */ | |
361 | if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1) { | |
362 | goto loop; | |
363 | } | |
364 | } | |
365 | ret = 1; | |
366 | ||
367 | err: | |
368 | BN_CTX_end(ctx); | |
369 | bn_check_top(rnd); | |
370 | return ret; | |
371 | } | |
e46a059e | 372 | |
7999c65c | 373 | static int witness(BIGNUM *w, const BIGNUM *a, const BIGNUM *a1, |
0f113f3e MC |
374 | const BIGNUM *a1_odd, int k, BN_CTX *ctx, |
375 | BN_MONT_CTX *mont) | |
376 | { | |
377 | if (!BN_mod_exp_mont(w, w, a1_odd, a, ctx, mont)) /* w := w^a1_odd mod a */ | |
378 | return -1; | |
379 | if (BN_is_one(w)) | |
380 | return 0; /* probably prime */ | |
381 | if (BN_cmp(w, a1) == 0) | |
382 | return 0; /* w == -1 (mod a), 'a' is probably prime */ | |
383 | while (--k) { | |
384 | if (!BN_mod_mul(w, w, w, a, ctx)) /* w := w^2 mod a */ | |
385 | return -1; | |
386 | if (BN_is_one(w)) | |
387 | return 1; /* 'a' is composite, otherwise a previous 'w' | |
388 | * would have been == -1 (mod 'a') */ | |
389 | if (BN_cmp(w, a1) == 0) | |
390 | return 0; /* w == -1 (mod a), 'a' is probably prime */ | |
391 | } | |
392 | /* | |
393 | * If we get here, 'w' is the (a-1)/2-th power of the original 'w', and | |
394 | * it is neither -1 nor +1 -- so 'a' cannot be prime | |
395 | */ | |
396 | bn_check_top(w); | |
397 | return 1; | |
398 | } | |
d02b48c6 | 399 | |
8e704858 | 400 | static int probable_prime(BIGNUM *rnd, int bits, prime_t *mods) |
0f113f3e MC |
401 | { |
402 | int i; | |
0f113f3e MC |
403 | BN_ULONG delta; |
404 | BN_ULONG maxdelta = BN_MASK2 - primes[NUMPRIMES - 1]; | |
405 | char is_single_word = bits <= BN_BITS2; | |
406 | ||
407 | again: | |
408 | if (!BN_rand(rnd, bits, 1, 1)) | |
409 | return (0); | |
410 | /* we now have a random number 'rnd' to test. */ | |
411 | for (i = 1; i < NUMPRIMES; i++) | |
412 | mods[i] = (prime_t) BN_mod_word(rnd, (BN_ULONG)primes[i]); | |
413 | /* | |
414 | * If bits is so small that it fits into a single word then we | |
415 | * additionally don't want to exceed that many bits. | |
416 | */ | |
417 | if (is_single_word) { | |
e4676e90 MC |
418 | BN_ULONG size_limit; |
419 | ||
420 | if (bits == BN_BITS2) { | |
421 | /* | |
422 | * Shifting by this much has undefined behaviour so we do it a | |
423 | * different way | |
424 | */ | |
425 | size_limit = ~((BN_ULONG)0) - BN_get_word(rnd); | |
426 | } else { | |
427 | size_limit = (((BN_ULONG)1) << bits) - BN_get_word(rnd) - 1; | |
428 | } | |
0f113f3e MC |
429 | if (size_limit < maxdelta) |
430 | maxdelta = size_limit; | |
431 | } | |
432 | delta = 0; | |
433 | loop: | |
434 | if (is_single_word) { | |
435 | BN_ULONG rnd_word = BN_get_word(rnd); | |
436 | ||
50e735f9 MC |
437 | /*- |
438 | * In the case that the candidate prime is a single word then | |
439 | * we check that: | |
440 | * 1) It's greater than primes[i] because we shouldn't reject | |
441 | * 3 as being a prime number because it's a multiple of | |
442 | * three. | |
443 | * 2) That it's not a multiple of a known prime. We don't | |
444 | * check that rnd-1 is also coprime to all the known | |
445 | * primes because there aren't many small primes where | |
446 | * that's true. | |
447 | */ | |
0f113f3e MC |
448 | for (i = 1; i < NUMPRIMES && primes[i] < rnd_word; i++) { |
449 | if ((mods[i] + delta) % primes[i] == 0) { | |
450 | delta += 2; | |
451 | if (delta > maxdelta) | |
452 | goto again; | |
453 | goto loop; | |
454 | } | |
455 | } | |
456 | } else { | |
457 | for (i = 1; i < NUMPRIMES; i++) { | |
458 | /* | |
459 | * check that rnd is not a prime and also that gcd(rnd-1,primes) | |
460 | * == 1 (except for 2) | |
461 | */ | |
462 | if (((mods[i] + delta) % primes[i]) <= 1) { | |
463 | delta += 2; | |
464 | if (delta > maxdelta) | |
465 | goto again; | |
466 | goto loop; | |
467 | } | |
468 | } | |
469 | } | |
470 | if (!BN_add_word(rnd, delta)) | |
471 | return (0); | |
472 | if (BN_num_bits(rnd) != bits) | |
473 | goto again; | |
474 | bn_check_top(rnd); | |
475 | return (1); | |
476 | } | |
d02b48c6 | 477 | |
982c42cb | 478 | int bn_probable_prime_dh(BIGNUM *rnd, int bits, |
0f113f3e MC |
479 | const BIGNUM *add, const BIGNUM *rem, BN_CTX *ctx) |
480 | { | |
481 | int i, ret = 0; | |
482 | BIGNUM *t1; | |
483 | ||
484 | BN_CTX_start(ctx); | |
485 | if ((t1 = BN_CTX_get(ctx)) == NULL) | |
486 | goto err; | |
487 | ||
488 | if (!BN_rand(rnd, bits, 0, 1)) | |
489 | goto err; | |
490 | ||
491 | /* we need ((rnd-rem) % add) == 0 */ | |
492 | ||
493 | if (!BN_mod(t1, rnd, add, ctx)) | |
494 | goto err; | |
495 | if (!BN_sub(rnd, rnd, t1)) | |
496 | goto err; | |
497 | if (rem == NULL) { | |
498 | if (!BN_add_word(rnd, 1)) | |
499 | goto err; | |
500 | } else { | |
501 | if (!BN_add(rnd, rnd, rem)) | |
502 | goto err; | |
503 | } | |
504 | ||
505 | /* we now have a random number 'rand' to test. */ | |
506 | ||
507 | loop: | |
508 | for (i = 1; i < NUMPRIMES; i++) { | |
509 | /* check that rnd is a prime */ | |
510 | if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1) { | |
511 | if (!BN_add(rnd, rnd, add)) | |
512 | goto err; | |
513 | goto loop; | |
514 | } | |
515 | } | |
516 | ret = 1; | |
517 | ||
518 | err: | |
519 | BN_CTX_end(ctx); | |
520 | bn_check_top(rnd); | |
521 | return (ret); | |
522 | } | |
b0513819 | 523 | |
020fc820 | 524 | static int probable_prime_dh_safe(BIGNUM *p, int bits, const BIGNUM *padd, |
0f113f3e MC |
525 | const BIGNUM *rem, BN_CTX *ctx) |
526 | { | |
527 | int i, ret = 0; | |
528 | BIGNUM *t1, *qadd, *q; | |
529 | ||
530 | bits--; | |
531 | BN_CTX_start(ctx); | |
532 | t1 = BN_CTX_get(ctx); | |
533 | q = BN_CTX_get(ctx); | |
534 | qadd = BN_CTX_get(ctx); | |
535 | if (qadd == NULL) | |
536 | goto err; | |
537 | ||
538 | if (!BN_rshift1(qadd, padd)) | |
539 | goto err; | |
540 | ||
541 | if (!BN_rand(q, bits, 0, 1)) | |
542 | goto err; | |
543 | ||
544 | /* we need ((rnd-rem) % add) == 0 */ | |
545 | if (!BN_mod(t1, q, qadd, ctx)) | |
546 | goto err; | |
547 | if (!BN_sub(q, q, t1)) | |
548 | goto err; | |
549 | if (rem == NULL) { | |
550 | if (!BN_add_word(q, 1)) | |
551 | goto err; | |
552 | } else { | |
553 | if (!BN_rshift1(t1, rem)) | |
554 | goto err; | |
555 | if (!BN_add(q, q, t1)) | |
556 | goto err; | |
557 | } | |
558 | ||
559 | /* we now have a random number 'rand' to test. */ | |
560 | if (!BN_lshift1(p, q)) | |
561 | goto err; | |
562 | if (!BN_add_word(p, 1)) | |
563 | goto err; | |
564 | ||
565 | loop: | |
566 | for (i = 1; i < NUMPRIMES; i++) { | |
567 | /* check that p and q are prime */ | |
568 | /* | |
569 | * check that for p and q gcd(p-1,primes) == 1 (except for 2) | |
570 | */ | |
571 | if ((BN_mod_word(p, (BN_ULONG)primes[i]) == 0) || | |
572 | (BN_mod_word(q, (BN_ULONG)primes[i]) == 0)) { | |
573 | if (!BN_add(p, p, padd)) | |
574 | goto err; | |
575 | if (!BN_add(q, q, qadd)) | |
576 | goto err; | |
577 | goto loop; | |
578 | } | |
579 | } | |
580 | ret = 1; | |
581 | ||
582 | err: | |
583 | BN_CTX_end(ctx); | |
584 | bn_check_top(p); | |
585 | return (ret); | |
586 | } |