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d02b48c6 | 1 | /* crypto/dsa/dsa_gen.c */ |
58964a49 | 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
d02b48c6 RE |
3 | * All rights reserved. |
4 | * | |
5 | * This package is an SSL implementation written | |
6 | * by Eric Young (eay@cryptsoft.com). | |
7 | * The implementation was written so as to conform with Netscapes SSL. | |
0f113f3e | 8 | * |
d02b48c6 RE |
9 | * This library is free for commercial and non-commercial use as long as |
10 | * the following conditions are aheared to. The following conditions | |
11 | * apply to all code found in this distribution, be it the RC4, RSA, | |
12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | |
13 | * included with this distribution is covered by the same copyright terms | |
14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | |
0f113f3e | 15 | * |
d02b48c6 RE |
16 | * Copyright remains Eric Young's, and as such any Copyright notices in |
17 | * the code are not to be removed. | |
18 | * If this package is used in a product, Eric Young should be given attribution | |
19 | * as the author of the parts of the library used. | |
20 | * This can be in the form of a textual message at program startup or | |
21 | * in documentation (online or textual) provided with the package. | |
0f113f3e | 22 | * |
d02b48c6 RE |
23 | * Redistribution and use in source and binary forms, with or without |
24 | * modification, are permitted provided that the following conditions | |
25 | * are met: | |
26 | * 1. Redistributions of source code must retain the copyright | |
27 | * notice, this list of conditions and the following disclaimer. | |
28 | * 2. Redistributions in binary form must reproduce the above copyright | |
29 | * notice, this list of conditions and the following disclaimer in the | |
30 | * documentation and/or other materials provided with the distribution. | |
31 | * 3. All advertising materials mentioning features or use of this software | |
32 | * must display the following acknowledgement: | |
33 | * "This product includes cryptographic software written by | |
34 | * Eric Young (eay@cryptsoft.com)" | |
35 | * The word 'cryptographic' can be left out if the rouines from the library | |
36 | * being used are not cryptographic related :-). | |
0f113f3e | 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
38 | * the apps directory (application code) you must include an acknowledgement: |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
0f113f3e | 40 | * |
d02b48c6 RE |
41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
51 | * SUCH DAMAGE. | |
0f113f3e | 52 | * |
d02b48c6 RE |
53 | * The licence and distribution terms for any publically available version or |
54 | * derivative of this code cannot be changed. i.e. this code cannot simply be | |
55 | * copied and put under another distribution licence | |
56 | * [including the GNU Public Licence.] | |
57 | */ | |
58 | ||
0f113f3e MC |
59 | /* |
60 | * Parameter generation follows the updated Appendix 2.2 for FIPS PUB 186, | |
61 | * also Appendix 2.2 of FIPS PUB 186-1 (i.e. use SHA as defined in FIPS PUB | |
62 | * 180-1) | |
63 | */ | |
474e469b | 64 | #define xxxHASH EVP_sha1() |
d02b48c6 | 65 | |
751ff1d3 RL |
66 | #include <openssl/opensslconf.h> /* To see if OPENSSL_NO_SHA is defined */ |
67 | ||
474e469b RS |
68 | #include <stdio.h> |
69 | #include "cryptlib.h" | |
70 | #include <openssl/evp.h> | |
71 | #include <openssl/bn.h> | |
72 | #include <openssl/rand.h> | |
73 | #include <openssl/sha.h> | |
a87030a1 | 74 | |
474e469b | 75 | #include "dsa_locl.h" |
0e4aa0d2 | 76 | |
e9224c71 | 77 | int DSA_generate_parameters_ex(DSA *ret, int bits, |
0f113f3e MC |
78 | const unsigned char *seed_in, int seed_len, |
79 | int *counter_ret, unsigned long *h_ret, | |
80 | BN_GENCB *cb) | |
81 | { | |
82 | if (ret->meth->dsa_paramgen) | |
83 | return ret->meth->dsa_paramgen(ret, bits, seed_in, seed_len, | |
84 | counter_ret, h_ret, cb); | |
85 | else { | |
86 | const EVP_MD *evpmd; | |
87 | size_t qbits = bits >= 2048 ? 256 : 160; | |
88 | ||
89 | if (bits >= 2048) { | |
90 | qbits = 256; | |
91 | evpmd = EVP_sha256(); | |
92 | } else { | |
93 | qbits = 160; | |
94 | evpmd = EVP_sha1(); | |
95 | } | |
96 | ||
97 | return dsa_builtin_paramgen(ret, bits, qbits, evpmd, | |
98 | seed_in, seed_len, NULL, counter_ret, | |
99 | h_ret, cb); | |
100 | } | |
101 | } | |
0e4aa0d2 | 102 | |
357d5de5 | 103 | int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits, |
0f113f3e MC |
104 | const EVP_MD *evpmd, const unsigned char *seed_in, |
105 | size_t seed_len, unsigned char *seed_out, | |
106 | int *counter_ret, unsigned long *h_ret, BN_GENCB *cb) | |
107 | { | |
108 | int ok = 0; | |
109 | unsigned char seed[SHA256_DIGEST_LENGTH]; | |
110 | unsigned char md[SHA256_DIGEST_LENGTH]; | |
111 | unsigned char buf[SHA256_DIGEST_LENGTH], buf2[SHA256_DIGEST_LENGTH]; | |
112 | BIGNUM *r0, *W, *X, *c, *test; | |
113 | BIGNUM *g = NULL, *q = NULL, *p = NULL; | |
114 | BN_MONT_CTX *mont = NULL; | |
115 | int i, k, n = 0, m = 0, qsize = qbits >> 3; | |
116 | int counter = 0; | |
117 | int r = 0; | |
118 | BN_CTX *ctx = NULL; | |
119 | unsigned int h = 2; | |
120 | ||
121 | if (qsize != SHA_DIGEST_LENGTH && qsize != SHA224_DIGEST_LENGTH && | |
122 | qsize != SHA256_DIGEST_LENGTH) | |
123 | /* invalid q size */ | |
124 | return 0; | |
125 | ||
126 | if (evpmd == NULL) | |
127 | /* use SHA1 as default */ | |
128 | evpmd = EVP_sha1(); | |
129 | ||
130 | if (bits < 512) | |
131 | bits = 512; | |
132 | ||
133 | bits = (bits + 63) / 64 * 64; | |
134 | ||
135 | /* | |
136 | * NB: seed_len == 0 is special case: copy generated seed to seed_in if | |
137 | * it is not NULL. | |
138 | */ | |
139 | if (seed_len && (seed_len < (size_t)qsize)) | |
140 | seed_in = NULL; /* seed buffer too small -- ignore */ | |
141 | if (seed_len > (size_t)qsize) | |
142 | seed_len = qsize; /* App. 2.2 of FIPS PUB 186 allows larger | |
143 | * SEED, but our internal buffers are | |
144 | * restricted to 160 bits */ | |
145 | if (seed_in != NULL) | |
146 | memcpy(seed, seed_in, seed_len); | |
147 | ||
148 | if ((ctx = BN_CTX_new()) == NULL) | |
149 | goto err; | |
150 | ||
151 | if ((mont = BN_MONT_CTX_new()) == NULL) | |
152 | goto err; | |
153 | ||
154 | BN_CTX_start(ctx); | |
155 | r0 = BN_CTX_get(ctx); | |
156 | g = BN_CTX_get(ctx); | |
157 | W = BN_CTX_get(ctx); | |
158 | q = BN_CTX_get(ctx); | |
159 | X = BN_CTX_get(ctx); | |
160 | c = BN_CTX_get(ctx); | |
161 | p = BN_CTX_get(ctx); | |
162 | test = BN_CTX_get(ctx); | |
163 | ||
164 | if (!BN_lshift(test, BN_value_one(), bits - 1)) | |
165 | goto err; | |
166 | ||
167 | for (;;) { | |
168 | for (;;) { /* find q */ | |
169 | int seed_is_random; | |
170 | ||
171 | /* step 1 */ | |
172 | if (!BN_GENCB_call(cb, 0, m++)) | |
173 | goto err; | |
174 | ||
175 | if (!seed_len) { | |
266483d2 | 176 | if (RAND_bytes(seed, qsize) <= 0) |
0f113f3e MC |
177 | goto err; |
178 | seed_is_random = 1; | |
179 | } else { | |
180 | seed_is_random = 0; | |
181 | seed_len = 0; /* use random seed if 'seed_in' turns out to | |
182 | * be bad */ | |
183 | } | |
184 | memcpy(buf, seed, qsize); | |
185 | memcpy(buf2, seed, qsize); | |
186 | /* precompute "SEED + 1" for step 7: */ | |
187 | for (i = qsize - 1; i >= 0; i--) { | |
188 | buf[i]++; | |
189 | if (buf[i] != 0) | |
190 | break; | |
191 | } | |
192 | ||
193 | /* step 2 */ | |
194 | if (!EVP_Digest(seed, qsize, md, NULL, evpmd, NULL)) | |
195 | goto err; | |
196 | if (!EVP_Digest(buf, qsize, buf2, NULL, evpmd, NULL)) | |
197 | goto err; | |
198 | for (i = 0; i < qsize; i++) | |
199 | md[i] ^= buf2[i]; | |
200 | ||
201 | /* step 3 */ | |
202 | md[0] |= 0x80; | |
203 | md[qsize - 1] |= 0x01; | |
204 | if (!BN_bin2bn(md, qsize, q)) | |
205 | goto err; | |
206 | ||
207 | /* step 4 */ | |
208 | r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, | |
209 | seed_is_random, cb); | |
210 | if (r > 0) | |
211 | break; | |
212 | if (r != 0) | |
213 | goto err; | |
214 | ||
215 | /* do a callback call */ | |
216 | /* step 5 */ | |
217 | } | |
218 | ||
219 | if (!BN_GENCB_call(cb, 2, 0)) | |
220 | goto err; | |
221 | if (!BN_GENCB_call(cb, 3, 0)) | |
222 | goto err; | |
223 | ||
224 | /* step 6 */ | |
225 | counter = 0; | |
226 | /* "offset = 2" */ | |
227 | ||
228 | n = (bits - 1) / 160; | |
229 | ||
230 | for (;;) { | |
231 | if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) | |
232 | goto err; | |
233 | ||
234 | /* step 7 */ | |
235 | BN_zero(W); | |
236 | /* now 'buf' contains "SEED + offset - 1" */ | |
237 | for (k = 0; k <= n; k++) { | |
238 | /* | |
239 | * obtain "SEED + offset + k" by incrementing: | |
240 | */ | |
241 | for (i = qsize - 1; i >= 0; i--) { | |
242 | buf[i]++; | |
243 | if (buf[i] != 0) | |
244 | break; | |
245 | } | |
246 | ||
247 | if (!EVP_Digest(buf, qsize, md, NULL, evpmd, NULL)) | |
248 | goto err; | |
249 | ||
250 | /* step 8 */ | |
251 | if (!BN_bin2bn(md, qsize, r0)) | |
252 | goto err; | |
253 | if (!BN_lshift(r0, r0, (qsize << 3) * k)) | |
254 | goto err; | |
255 | if (!BN_add(W, W, r0)) | |
256 | goto err; | |
257 | } | |
258 | ||
259 | /* more of step 8 */ | |
260 | if (!BN_mask_bits(W, bits - 1)) | |
261 | goto err; | |
262 | if (!BN_copy(X, W)) | |
263 | goto err; | |
264 | if (!BN_add(X, X, test)) | |
265 | goto err; | |
266 | ||
267 | /* step 9 */ | |
268 | if (!BN_lshift1(r0, q)) | |
269 | goto err; | |
270 | if (!BN_mod(c, X, r0, ctx)) | |
271 | goto err; | |
272 | if (!BN_sub(r0, c, BN_value_one())) | |
273 | goto err; | |
274 | if (!BN_sub(p, X, r0)) | |
275 | goto err; | |
276 | ||
277 | /* step 10 */ | |
278 | if (BN_cmp(p, test) >= 0) { | |
279 | /* step 11 */ | |
280 | r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb); | |
281 | if (r > 0) | |
282 | goto end; /* found it */ | |
283 | if (r != 0) | |
284 | goto err; | |
285 | } | |
286 | ||
287 | /* step 13 */ | |
288 | counter++; | |
289 | /* "offset = offset + n + 1" */ | |
290 | ||
291 | /* step 14 */ | |
292 | if (counter >= 4096) | |
293 | break; | |
294 | } | |
295 | } | |
296 | end: | |
297 | if (!BN_GENCB_call(cb, 2, 1)) | |
298 | goto err; | |
299 | ||
300 | /* We now need to generate g */ | |
301 | /* Set r0=(p-1)/q */ | |
302 | if (!BN_sub(test, p, BN_value_one())) | |
303 | goto err; | |
304 | if (!BN_div(r0, NULL, test, q, ctx)) | |
305 | goto err; | |
306 | ||
307 | if (!BN_set_word(test, h)) | |
308 | goto err; | |
309 | if (!BN_MONT_CTX_set(mont, p, ctx)) | |
310 | goto err; | |
311 | ||
312 | for (;;) { | |
313 | /* g=test^r0%p */ | |
314 | if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont)) | |
315 | goto err; | |
316 | if (!BN_is_one(g)) | |
317 | break; | |
318 | if (!BN_add(test, test, BN_value_one())) | |
319 | goto err; | |
320 | h++; | |
321 | } | |
322 | ||
323 | if (!BN_GENCB_call(cb, 3, 1)) | |
324 | goto err; | |
325 | ||
326 | ok = 1; | |
327 | err: | |
328 | if (ok) { | |
329 | if (ret->p) | |
330 | BN_free(ret->p); | |
331 | if (ret->q) | |
332 | BN_free(ret->q); | |
333 | if (ret->g) | |
334 | BN_free(ret->g); | |
335 | ret->p = BN_dup(p); | |
336 | ret->q = BN_dup(q); | |
337 | ret->g = BN_dup(g); | |
338 | if (ret->p == NULL || ret->q == NULL || ret->g == NULL) { | |
339 | ok = 0; | |
340 | goto err; | |
341 | } | |
342 | if (counter_ret != NULL) | |
343 | *counter_ret = counter; | |
344 | if (h_ret != NULL) | |
345 | *h_ret = h; | |
346 | if (seed_out) | |
347 | memcpy(seed_out, seed, qsize); | |
348 | } | |
349 | if (ctx) { | |
350 | BN_CTX_end(ctx); | |
351 | BN_CTX_free(ctx); | |
352 | } | |
353 | if (mont != NULL) | |
354 | BN_MONT_CTX_free(mont); | |
355 | return ok; | |
356 | } | |
357 | ||
358 | /* | |
359 | * This is a parameter generation algorithm for the DSA2 algorithm as | |
3dd9b31d DSH |
360 | * described in FIPS 186-3. |
361 | */ | |
362 | ||
363 | int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N, | |
0f113f3e MC |
364 | const EVP_MD *evpmd, const unsigned char *seed_in, |
365 | size_t seed_len, int idx, unsigned char *seed_out, | |
366 | int *counter_ret, unsigned long *h_ret, | |
367 | BN_GENCB *cb) | |
368 | { | |
369 | int ok = -1; | |
370 | unsigned char *seed = NULL, *seed_tmp = NULL; | |
371 | unsigned char md[EVP_MAX_MD_SIZE]; | |
372 | int mdsize; | |
373 | BIGNUM *r0, *W, *X, *c, *test; | |
374 | BIGNUM *g = NULL, *q = NULL, *p = NULL; | |
375 | BN_MONT_CTX *mont = NULL; | |
376 | int i, k, n = 0, m = 0, qsize = N >> 3; | |
377 | int counter = 0; | |
378 | int r = 0; | |
379 | BN_CTX *ctx = NULL; | |
380 | EVP_MD_CTX mctx; | |
381 | unsigned int h = 2; | |
382 | ||
383 | EVP_MD_CTX_init(&mctx); | |
384 | ||
385 | if (evpmd == NULL) { | |
386 | if (N == 160) | |
387 | evpmd = EVP_sha1(); | |
388 | else if (N == 224) | |
389 | evpmd = EVP_sha224(); | |
390 | else | |
391 | evpmd = EVP_sha256(); | |
392 | } | |
393 | ||
394 | mdsize = M_EVP_MD_size(evpmd); | |
395 | /* If unverificable g generation only don't need seed */ | |
396 | if (!ret->p || !ret->q || idx >= 0) { | |
397 | if (seed_len == 0) | |
398 | seed_len = mdsize; | |
399 | ||
400 | seed = OPENSSL_malloc(seed_len); | |
401 | ||
402 | if (seed_out) | |
403 | seed_tmp = seed_out; | |
404 | else | |
405 | seed_tmp = OPENSSL_malloc(seed_len); | |
406 | ||
407 | if (!seed || !seed_tmp) | |
408 | goto err; | |
409 | ||
410 | if (seed_in) | |
411 | memcpy(seed, seed_in, seed_len); | |
412 | ||
413 | } | |
414 | ||
415 | if ((ctx = BN_CTX_new()) == NULL) | |
416 | goto err; | |
417 | ||
418 | if ((mont = BN_MONT_CTX_new()) == NULL) | |
419 | goto err; | |
420 | ||
421 | BN_CTX_start(ctx); | |
422 | r0 = BN_CTX_get(ctx); | |
423 | g = BN_CTX_get(ctx); | |
424 | W = BN_CTX_get(ctx); | |
425 | X = BN_CTX_get(ctx); | |
426 | c = BN_CTX_get(ctx); | |
427 | test = BN_CTX_get(ctx); | |
428 | ||
429 | /* if p, q already supplied generate g only */ | |
430 | if (ret->p && ret->q) { | |
431 | p = ret->p; | |
432 | q = ret->q; | |
433 | if (idx >= 0) | |
434 | memcpy(seed_tmp, seed, seed_len); | |
435 | goto g_only; | |
436 | } else { | |
437 | p = BN_CTX_get(ctx); | |
438 | q = BN_CTX_get(ctx); | |
439 | } | |
440 | ||
441 | if (!BN_lshift(test, BN_value_one(), L - 1)) | |
442 | goto err; | |
443 | for (;;) { | |
444 | for (;;) { /* find q */ | |
445 | unsigned char *pmd; | |
446 | /* step 1 */ | |
447 | if (!BN_GENCB_call(cb, 0, m++)) | |
448 | goto err; | |
449 | ||
450 | if (!seed_in) { | |
266483d2 | 451 | if (RAND_bytes(seed, seed_len) <= 0) |
0f113f3e MC |
452 | goto err; |
453 | } | |
454 | /* step 2 */ | |
455 | if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL)) | |
456 | goto err; | |
457 | /* Take least significant bits of md */ | |
458 | if (mdsize > qsize) | |
459 | pmd = md + mdsize - qsize; | |
460 | else | |
461 | pmd = md; | |
462 | ||
463 | if (mdsize < qsize) | |
464 | memset(md + mdsize, 0, qsize - mdsize); | |
465 | ||
466 | /* step 3 */ | |
467 | pmd[0] |= 0x80; | |
468 | pmd[qsize - 1] |= 0x01; | |
469 | if (!BN_bin2bn(pmd, qsize, q)) | |
470 | goto err; | |
471 | ||
472 | /* step 4 */ | |
473 | r = BN_is_prime_fasttest_ex(q, DSS_prime_checks, ctx, | |
474 | seed_in ? 1 : 0, cb); | |
475 | if (r > 0) | |
476 | break; | |
477 | if (r != 0) | |
478 | goto err; | |
479 | /* Provided seed didn't produce a prime: error */ | |
480 | if (seed_in) { | |
481 | ok = 0; | |
482 | DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_Q_NOT_PRIME); | |
483 | goto err; | |
484 | } | |
485 | ||
486 | /* do a callback call */ | |
487 | /* step 5 */ | |
488 | } | |
489 | /* Copy seed to seed_out before we mess with it */ | |
490 | if (seed_out) | |
491 | memcpy(seed_out, seed, seed_len); | |
492 | ||
493 | if (!BN_GENCB_call(cb, 2, 0)) | |
494 | goto err; | |
495 | if (!BN_GENCB_call(cb, 3, 0)) | |
496 | goto err; | |
497 | ||
498 | /* step 6 */ | |
499 | counter = 0; | |
500 | /* "offset = 1" */ | |
501 | ||
502 | n = (L - 1) / (mdsize << 3); | |
503 | ||
504 | for (;;) { | |
505 | if ((counter != 0) && !BN_GENCB_call(cb, 0, counter)) | |
506 | goto err; | |
507 | ||
508 | /* step 7 */ | |
509 | BN_zero(W); | |
510 | /* now 'buf' contains "SEED + offset - 1" */ | |
511 | for (k = 0; k <= n; k++) { | |
512 | /* | |
513 | * obtain "SEED + offset + k" by incrementing: | |
514 | */ | |
515 | for (i = seed_len - 1; i >= 0; i--) { | |
516 | seed[i]++; | |
517 | if (seed[i] != 0) | |
518 | break; | |
519 | } | |
520 | ||
521 | if (!EVP_Digest(seed, seed_len, md, NULL, evpmd, NULL)) | |
522 | goto err; | |
523 | ||
524 | /* step 8 */ | |
525 | if (!BN_bin2bn(md, mdsize, r0)) | |
526 | goto err; | |
527 | if (!BN_lshift(r0, r0, (mdsize << 3) * k)) | |
528 | goto err; | |
529 | if (!BN_add(W, W, r0)) | |
530 | goto err; | |
531 | } | |
532 | ||
533 | /* more of step 8 */ | |
534 | if (!BN_mask_bits(W, L - 1)) | |
535 | goto err; | |
536 | if (!BN_copy(X, W)) | |
537 | goto err; | |
538 | if (!BN_add(X, X, test)) | |
539 | goto err; | |
540 | ||
541 | /* step 9 */ | |
542 | if (!BN_lshift1(r0, q)) | |
543 | goto err; | |
544 | if (!BN_mod(c, X, r0, ctx)) | |
545 | goto err; | |
546 | if (!BN_sub(r0, c, BN_value_one())) | |
547 | goto err; | |
548 | if (!BN_sub(p, X, r0)) | |
549 | goto err; | |
550 | ||
551 | /* step 10 */ | |
552 | if (BN_cmp(p, test) >= 0) { | |
553 | /* step 11 */ | |
554 | r = BN_is_prime_fasttest_ex(p, DSS_prime_checks, ctx, 1, cb); | |
555 | if (r > 0) | |
556 | goto end; /* found it */ | |
557 | if (r != 0) | |
558 | goto err; | |
559 | } | |
560 | ||
561 | /* step 13 */ | |
562 | counter++; | |
563 | /* "offset = offset + n + 1" */ | |
564 | ||
565 | /* step 14 */ | |
566 | if (counter >= (int)(4 * L)) | |
567 | break; | |
568 | } | |
569 | if (seed_in) { | |
570 | ok = 0; | |
571 | DSAerr(DSA_F_DSA_BUILTIN_PARAMGEN2, DSA_R_INVALID_PARAMETERS); | |
572 | goto err; | |
573 | } | |
574 | } | |
575 | end: | |
576 | if (!BN_GENCB_call(cb, 2, 1)) | |
577 | goto err; | |
578 | ||
579 | g_only: | |
580 | ||
581 | /* We now need to generate g */ | |
582 | /* Set r0=(p-1)/q */ | |
583 | if (!BN_sub(test, p, BN_value_one())) | |
584 | goto err; | |
585 | if (!BN_div(r0, NULL, test, q, ctx)) | |
586 | goto err; | |
587 | ||
588 | if (idx < 0) { | |
589 | if (!BN_set_word(test, h)) | |
590 | goto err; | |
591 | } else | |
592 | h = 1; | |
593 | if (!BN_MONT_CTX_set(mont, p, ctx)) | |
594 | goto err; | |
595 | ||
596 | for (;;) { | |
597 | static const unsigned char ggen[4] = { 0x67, 0x67, 0x65, 0x6e }; | |
598 | if (idx >= 0) { | |
599 | md[0] = idx & 0xff; | |
600 | md[1] = (h >> 8) & 0xff; | |
601 | md[2] = h & 0xff; | |
602 | if (!EVP_DigestInit_ex(&mctx, evpmd, NULL)) | |
603 | goto err; | |
604 | if (!EVP_DigestUpdate(&mctx, seed_tmp, seed_len)) | |
605 | goto err; | |
606 | if (!EVP_DigestUpdate(&mctx, ggen, sizeof(ggen))) | |
607 | goto err; | |
608 | if (!EVP_DigestUpdate(&mctx, md, 3)) | |
609 | goto err; | |
610 | if (!EVP_DigestFinal_ex(&mctx, md, NULL)) | |
611 | goto err; | |
612 | if (!BN_bin2bn(md, mdsize, test)) | |
613 | goto err; | |
614 | } | |
615 | /* g=test^r0%p */ | |
616 | if (!BN_mod_exp_mont(g, test, r0, p, ctx, mont)) | |
617 | goto err; | |
618 | if (!BN_is_one(g)) | |
619 | break; | |
620 | if (idx < 0 && !BN_add(test, test, BN_value_one())) | |
621 | goto err; | |
622 | h++; | |
623 | if (idx >= 0 && h > 0xffff) | |
624 | goto err; | |
625 | } | |
626 | ||
627 | if (!BN_GENCB_call(cb, 3, 1)) | |
628 | goto err; | |
629 | ||
630 | ok = 1; | |
631 | err: | |
632 | if (ok == 1) { | |
633 | if (p != ret->p) { | |
634 | if (ret->p) | |
635 | BN_free(ret->p); | |
636 | ret->p = BN_dup(p); | |
637 | } | |
638 | if (q != ret->q) { | |
639 | if (ret->q) | |
640 | BN_free(ret->q); | |
641 | ret->q = BN_dup(q); | |
642 | } | |
643 | if (ret->g) | |
644 | BN_free(ret->g); | |
645 | ret->g = BN_dup(g); | |
646 | if (ret->p == NULL || ret->q == NULL || ret->g == NULL) { | |
647 | ok = -1; | |
648 | goto err; | |
649 | } | |
650 | if (counter_ret != NULL) | |
651 | *counter_ret = counter; | |
652 | if (h_ret != NULL) | |
653 | *h_ret = h; | |
654 | } | |
655 | if (seed) | |
656 | OPENSSL_free(seed); | |
657 | if (seed_out != seed_tmp) | |
658 | OPENSSL_free(seed_tmp); | |
659 | if (ctx) { | |
660 | BN_CTX_end(ctx); | |
661 | BN_CTX_free(ctx); | |
662 | } | |
663 | if (mont != NULL) | |
664 | BN_MONT_CTX_free(mont); | |
665 | EVP_MD_CTX_cleanup(&mctx); | |
666 | return ok; | |
667 | } | |
f55f5f77 DSH |
668 | |
669 | int dsa_paramgen_check_g(DSA *dsa) | |
0f113f3e MC |
670 | { |
671 | BN_CTX *ctx; | |
672 | BIGNUM *tmp; | |
673 | BN_MONT_CTX *mont = NULL; | |
674 | int rv = -1; | |
675 | ctx = BN_CTX_new(); | |
676 | if (!ctx) | |
677 | return -1; | |
678 | BN_CTX_start(ctx); | |
679 | if (BN_cmp(dsa->g, BN_value_one()) <= 0) | |
680 | return 0; | |
681 | if (BN_cmp(dsa->g, dsa->p) >= 0) | |
682 | return 0; | |
683 | tmp = BN_CTX_get(ctx); | |
684 | if (!tmp) | |
685 | goto err; | |
686 | if ((mont = BN_MONT_CTX_new()) == NULL) | |
687 | goto err; | |
688 | if (!BN_MONT_CTX_set(mont, dsa->p, ctx)) | |
689 | goto err; | |
690 | /* Work out g^q mod p */ | |
691 | if (!BN_mod_exp_mont(tmp, dsa->g, dsa->q, dsa->p, ctx, mont)) | |
692 | goto err; | |
693 | if (!BN_cmp(tmp, BN_value_one())) | |
694 | rv = 1; | |
695 | else | |
696 | rv = 0; | |
697 | err: | |
698 | BN_CTX_end(ctx); | |
699 | if (mont) | |
700 | BN_MONT_CTX_free(mont); | |
701 | BN_CTX_free(ctx); | |
702 | return rv; | |
703 | ||
704 | } |