1 | /* |
2 | * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved. |
3 | * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved |
4 | * |
5 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
6 | * this file except in compliance with the License. You can obtain a copy |
7 | * in the file LICENSE in the source distribution or at |
8 | * https://www.openssl.org/source/license.html |
9 | */ |
10 | |
11 | #include <string.h> |
12 | |
13 | #include <openssl/err.h> |
14 | #include <openssl/opensslv.h> |
15 | |
16 | #include "ec_local.h" |
17 | |
18 | /* functions for EC_GROUP objects */ |
19 | |
20 | EC_GROUP *EC_GROUP_new_ex(OPENSSL_CTX *libctx, const EC_METHOD *meth) |
21 | { |
22 | EC_GROUP *ret; |
23 | |
24 | if (meth == NULL) { |
25 | ECerr(EC_F_EC_GROUP_NEW_EX, EC_R_SLOT_FULL); |
26 | return NULL; |
27 | } |
28 | if (meth->group_init == 0) { |
29 | ECerr(EC_F_EC_GROUP_NEW_EX, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
30 | return NULL; |
31 | } |
32 | |
33 | ret = OPENSSL_zalloc(sizeof(*ret)); |
34 | if (ret == NULL) { |
35 | ECerr(EC_F_EC_GROUP_NEW_EX, ERR_R_MALLOC_FAILURE); |
36 | return NULL; |
37 | } |
38 | |
39 | ret->libctx = libctx; |
40 | ret->meth = meth; |
41 | if ((ret->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) { |
42 | ret->order = BN_new(); |
43 | if (ret->order == NULL) |
44 | goto err; |
45 | ret->cofactor = BN_new(); |
46 | if (ret->cofactor == NULL) |
47 | goto err; |
48 | } |
49 | ret->asn1_flag = OPENSSL_EC_NAMED_CURVE; |
50 | ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED; |
51 | if (!meth->group_init(ret)) |
52 | goto err; |
53 | return ret; |
54 | |
55 | err: |
56 | BN_free(ret->order); |
57 | BN_free(ret->cofactor); |
58 | OPENSSL_free(ret); |
59 | return NULL; |
60 | } |
61 | |
62 | #ifndef FIPS_MODE |
63 | EC_GROUP *EC_GROUP_new(const EC_METHOD *meth) |
64 | { |
65 | return EC_GROUP_new_ex(NULL, meth); |
66 | } |
67 | #endif |
68 | |
69 | void EC_pre_comp_free(EC_GROUP *group) |
70 | { |
71 | switch (group->pre_comp_type) { |
72 | case PCT_none: |
73 | break; |
74 | case PCT_nistz256: |
75 | #ifdef ECP_NISTZ256_ASM |
76 | EC_nistz256_pre_comp_free(group->pre_comp.nistz256); |
77 | #endif |
78 | break; |
79 | #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 |
80 | case PCT_nistp224: |
81 | EC_nistp224_pre_comp_free(group->pre_comp.nistp224); |
82 | break; |
83 | case PCT_nistp256: |
84 | EC_nistp256_pre_comp_free(group->pre_comp.nistp256); |
85 | break; |
86 | case PCT_nistp521: |
87 | EC_nistp521_pre_comp_free(group->pre_comp.nistp521); |
88 | break; |
89 | #else |
90 | case PCT_nistp224: |
91 | case PCT_nistp256: |
92 | case PCT_nistp521: |
93 | break; |
94 | #endif |
95 | case PCT_ec: |
96 | EC_ec_pre_comp_free(group->pre_comp.ec); |
97 | break; |
98 | } |
99 | group->pre_comp.ec = NULL; |
100 | } |
101 | |
102 | void EC_GROUP_free(EC_GROUP *group) |
103 | { |
104 | if (!group) |
105 | return; |
106 | |
107 | if (group->meth->group_finish != 0) |
108 | group->meth->group_finish(group); |
109 | |
110 | EC_pre_comp_free(group); |
111 | BN_MONT_CTX_free(group->mont_data); |
112 | EC_POINT_free(group->generator); |
113 | BN_free(group->order); |
114 | BN_free(group->cofactor); |
115 | OPENSSL_free(group->seed); |
116 | OPENSSL_free(group); |
117 | } |
118 | |
119 | #ifndef OPENSSL_NO_DEPRECATED_3_0 |
120 | void EC_GROUP_clear_free(EC_GROUP *group) |
121 | { |
122 | if (!group) |
123 | return; |
124 | |
125 | if (group->meth->group_clear_finish != 0) |
126 | group->meth->group_clear_finish(group); |
127 | else if (group->meth->group_finish != 0) |
128 | group->meth->group_finish(group); |
129 | |
130 | EC_pre_comp_free(group); |
131 | BN_MONT_CTX_free(group->mont_data); |
132 | EC_POINT_clear_free(group->generator); |
133 | BN_clear_free(group->order); |
134 | BN_clear_free(group->cofactor); |
135 | OPENSSL_clear_free(group->seed, group->seed_len); |
136 | OPENSSL_clear_free(group, sizeof(*group)); |
137 | } |
138 | #endif |
139 | |
140 | int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src) |
141 | { |
142 | if (dest->meth->group_copy == 0) { |
143 | ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
144 | return 0; |
145 | } |
146 | if (dest->meth != src->meth) { |
147 | ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS); |
148 | return 0; |
149 | } |
150 | if (dest == src) |
151 | return 1; |
152 | |
153 | dest->libctx = src->libctx; |
154 | dest->curve_name = src->curve_name; |
155 | |
156 | /* Copy precomputed */ |
157 | dest->pre_comp_type = src->pre_comp_type; |
158 | switch (src->pre_comp_type) { |
159 | case PCT_none: |
160 | dest->pre_comp.ec = NULL; |
161 | break; |
162 | case PCT_nistz256: |
163 | #ifdef ECP_NISTZ256_ASM |
164 | dest->pre_comp.nistz256 = EC_nistz256_pre_comp_dup(src->pre_comp.nistz256); |
165 | #endif |
166 | break; |
167 | #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128 |
168 | case PCT_nistp224: |
169 | dest->pre_comp.nistp224 = EC_nistp224_pre_comp_dup(src->pre_comp.nistp224); |
170 | break; |
171 | case PCT_nistp256: |
172 | dest->pre_comp.nistp256 = EC_nistp256_pre_comp_dup(src->pre_comp.nistp256); |
173 | break; |
174 | case PCT_nistp521: |
175 | dest->pre_comp.nistp521 = EC_nistp521_pre_comp_dup(src->pre_comp.nistp521); |
176 | break; |
177 | #else |
178 | case PCT_nistp224: |
179 | case PCT_nistp256: |
180 | case PCT_nistp521: |
181 | break; |
182 | #endif |
183 | case PCT_ec: |
184 | dest->pre_comp.ec = EC_ec_pre_comp_dup(src->pre_comp.ec); |
185 | break; |
186 | } |
187 | |
188 | if (src->mont_data != NULL) { |
189 | if (dest->mont_data == NULL) { |
190 | dest->mont_data = BN_MONT_CTX_new(); |
191 | if (dest->mont_data == NULL) |
192 | return 0; |
193 | } |
194 | if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data)) |
195 | return 0; |
196 | } else { |
197 | /* src->generator == NULL */ |
198 | BN_MONT_CTX_free(dest->mont_data); |
199 | dest->mont_data = NULL; |
200 | } |
201 | |
202 | if (src->generator != NULL) { |
203 | if (dest->generator == NULL) { |
204 | dest->generator = EC_POINT_new(dest); |
205 | if (dest->generator == NULL) |
206 | return 0; |
207 | } |
208 | if (!EC_POINT_copy(dest->generator, src->generator)) |
209 | return 0; |
210 | } else { |
211 | /* src->generator == NULL */ |
212 | EC_POINT_clear_free(dest->generator); |
213 | dest->generator = NULL; |
214 | } |
215 | |
216 | if ((src->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) { |
217 | if (!BN_copy(dest->order, src->order)) |
218 | return 0; |
219 | if (!BN_copy(dest->cofactor, src->cofactor)) |
220 | return 0; |
221 | } |
222 | |
223 | dest->asn1_flag = src->asn1_flag; |
224 | dest->asn1_form = src->asn1_form; |
225 | |
226 | if (src->seed) { |
227 | OPENSSL_free(dest->seed); |
228 | if ((dest->seed = OPENSSL_malloc(src->seed_len)) == NULL) { |
229 | ECerr(EC_F_EC_GROUP_COPY, ERR_R_MALLOC_FAILURE); |
230 | return 0; |
231 | } |
232 | if (!memcpy(dest->seed, src->seed, src->seed_len)) |
233 | return 0; |
234 | dest->seed_len = src->seed_len; |
235 | } else { |
236 | OPENSSL_free(dest->seed); |
237 | dest->seed = NULL; |
238 | dest->seed_len = 0; |
239 | } |
240 | |
241 | return dest->meth->group_copy(dest, src); |
242 | } |
243 | |
244 | EC_GROUP *EC_GROUP_dup(const EC_GROUP *a) |
245 | { |
246 | EC_GROUP *t = NULL; |
247 | int ok = 0; |
248 | |
249 | if (a == NULL) |
250 | return NULL; |
251 | |
252 | if ((t = EC_GROUP_new_ex(a->libctx, a->meth)) == NULL) |
253 | return NULL; |
254 | if (!EC_GROUP_copy(t, a)) |
255 | goto err; |
256 | |
257 | ok = 1; |
258 | |
259 | err: |
260 | if (!ok) { |
261 | EC_GROUP_free(t); |
262 | return NULL; |
263 | } |
264 | return t; |
265 | } |
266 | |
267 | const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group) |
268 | { |
269 | return group->meth; |
270 | } |
271 | |
272 | int EC_METHOD_get_field_type(const EC_METHOD *meth) |
273 | { |
274 | return meth->field_type; |
275 | } |
276 | |
277 | static int ec_precompute_mont_data(EC_GROUP *); |
278 | |
279 | /*- |
280 | * Try computing cofactor from the generator order (n) and field cardinality (q). |
281 | * This works for all curves of cryptographic interest. |
282 | * |
283 | * Hasse thm: q + 1 - 2*sqrt(q) <= n*h <= q + 1 + 2*sqrt(q) |
284 | * h_min = (q + 1 - 2*sqrt(q))/n |
285 | * h_max = (q + 1 + 2*sqrt(q))/n |
286 | * h_max - h_min = 4*sqrt(q)/n |
287 | * So if n > 4*sqrt(q) holds, there is only one possible value for h: |
288 | * h = \lfloor (h_min + h_max)/2 \rceil = \lfloor (q + 1)/n \rceil |
289 | * |
290 | * Otherwise, zero cofactor and return success. |
291 | */ |
292 | static int ec_guess_cofactor(EC_GROUP *group) { |
293 | int ret = 0; |
294 | BN_CTX *ctx = NULL; |
295 | BIGNUM *q = NULL; |
296 | |
297 | /*- |
298 | * If the cofactor is too large, we cannot guess it. |
299 | * The RHS of below is a strict overestimate of lg(4 * sqrt(q)) |
300 | */ |
301 | if (BN_num_bits(group->order) <= (BN_num_bits(group->field) + 1) / 2 + 3) { |
302 | /* default to 0 */ |
303 | BN_zero(group->cofactor); |
304 | /* return success */ |
305 | return 1; |
306 | } |
307 | |
308 | if ((ctx = BN_CTX_new_ex(group->libctx)) == NULL) |
309 | return 0; |
310 | |
311 | BN_CTX_start(ctx); |
312 | if ((q = BN_CTX_get(ctx)) == NULL) |
313 | goto err; |
314 | |
315 | /* set q = 2**m for binary fields; q = p otherwise */ |
316 | if (group->meth->field_type == NID_X9_62_characteristic_two_field) { |
317 | BN_zero(q); |
318 | if (!BN_set_bit(q, BN_num_bits(group->field) - 1)) |
319 | goto err; |
320 | } else { |
321 | if (!BN_copy(q, group->field)) |
322 | goto err; |
323 | } |
324 | |
325 | /* compute h = \lfloor (q + 1)/n \rceil = \lfloor (q + 1 + n/2)/n \rfloor */ |
326 | if (!BN_rshift1(group->cofactor, group->order) /* n/2 */ |
327 | || !BN_add(group->cofactor, group->cofactor, q) /* q + n/2 */ |
328 | /* q + 1 + n/2 */ |
329 | || !BN_add(group->cofactor, group->cofactor, BN_value_one()) |
330 | /* (q + 1 + n/2)/n */ |
331 | || !BN_div(group->cofactor, NULL, group->cofactor, group->order, ctx)) |
332 | goto err; |
333 | ret = 1; |
334 | err: |
335 | BN_CTX_end(ctx); |
336 | BN_CTX_free(ctx); |
337 | return ret; |
338 | } |
339 | |
340 | int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, |
341 | const BIGNUM *order, const BIGNUM *cofactor) |
342 | { |
343 | if (generator == NULL) { |
344 | ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER); |
345 | return 0; |
346 | } |
347 | |
348 | /* require group->field >= 1 */ |
349 | if (group->field == NULL || BN_is_zero(group->field) |
350 | || BN_is_negative(group->field)) { |
351 | ECerr(EC_F_EC_GROUP_SET_GENERATOR, EC_R_INVALID_FIELD); |
352 | return 0; |
353 | } |
354 | |
355 | /*- |
356 | * - require order >= 1 |
357 | * - enforce upper bound due to Hasse thm: order can be no more than one bit |
358 | * longer than field cardinality |
359 | */ |
360 | if (order == NULL || BN_is_zero(order) || BN_is_negative(order) |
361 | || BN_num_bits(order) > BN_num_bits(group->field) + 1) { |
362 | ECerr(EC_F_EC_GROUP_SET_GENERATOR, EC_R_INVALID_GROUP_ORDER); |
363 | return 0; |
364 | } |
365 | |
366 | /*- |
367 | * Unfortunately the cofactor is an optional field in many standards. |
368 | * Internally, the lib uses 0 cofactor as a marker for "unknown cofactor". |
369 | * So accept cofactor == NULL or cofactor >= 0. |
370 | */ |
371 | if (cofactor != NULL && BN_is_negative(cofactor)) { |
372 | ECerr(EC_F_EC_GROUP_SET_GENERATOR, EC_R_UNKNOWN_COFACTOR); |
373 | return 0; |
374 | } |
375 | |
376 | if (group->generator == NULL) { |
377 | group->generator = EC_POINT_new(group); |
378 | if (group->generator == NULL) |
379 | return 0; |
380 | } |
381 | if (!EC_POINT_copy(group->generator, generator)) |
382 | return 0; |
383 | |
384 | if (!BN_copy(group->order, order)) |
385 | return 0; |
386 | |
387 | /* Either take the provided positive cofactor, or try to compute it */ |
388 | if (cofactor != NULL && !BN_is_zero(cofactor)) { |
389 | if (!BN_copy(group->cofactor, cofactor)) |
390 | return 0; |
391 | } else if (!ec_guess_cofactor(group)) { |
392 | BN_zero(group->cofactor); |
393 | return 0; |
394 | } |
395 | |
396 | /* |
397 | * Some groups have an order with |
398 | * factors of two, which makes the Montgomery setup fail. |
399 | * |group->mont_data| will be NULL in this case. |
400 | */ |
401 | if (BN_is_odd(group->order)) { |
402 | return ec_precompute_mont_data(group); |
403 | } |
404 | |
405 | BN_MONT_CTX_free(group->mont_data); |
406 | group->mont_data = NULL; |
407 | return 1; |
408 | } |
409 | |
410 | const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group) |
411 | { |
412 | return group->generator; |
413 | } |
414 | |
415 | BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group) |
416 | { |
417 | return group->mont_data; |
418 | } |
419 | |
420 | int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx) |
421 | { |
422 | if (group->order == NULL) |
423 | return 0; |
424 | if (!BN_copy(order, group->order)) |
425 | return 0; |
426 | |
427 | return !BN_is_zero(order); |
428 | } |
429 | |
430 | const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group) |
431 | { |
432 | return group->order; |
433 | } |
434 | |
435 | int EC_GROUP_order_bits(const EC_GROUP *group) |
436 | { |
437 | return group->meth->group_order_bits(group); |
438 | } |
439 | |
440 | int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor, |
441 | BN_CTX *ctx) |
442 | { |
443 | |
444 | if (group->cofactor == NULL) |
445 | return 0; |
446 | if (!BN_copy(cofactor, group->cofactor)) |
447 | return 0; |
448 | |
449 | return !BN_is_zero(group->cofactor); |
450 | } |
451 | |
452 | const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group) |
453 | { |
454 | return group->cofactor; |
455 | } |
456 | |
457 | void EC_GROUP_set_curve_name(EC_GROUP *group, int nid) |
458 | { |
459 | group->curve_name = nid; |
460 | } |
461 | |
462 | int EC_GROUP_get_curve_name(const EC_GROUP *group) |
463 | { |
464 | return group->curve_name; |
465 | } |
466 | |
467 | const BIGNUM *EC_GROUP_get0_field(const EC_GROUP *group) |
468 | { |
469 | return group->field; |
470 | } |
471 | |
472 | void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag) |
473 | { |
474 | group->asn1_flag = flag; |
475 | } |
476 | |
477 | int EC_GROUP_get_asn1_flag(const EC_GROUP *group) |
478 | { |
479 | return group->asn1_flag; |
480 | } |
481 | |
482 | void EC_GROUP_set_point_conversion_form(EC_GROUP *group, |
483 | point_conversion_form_t form) |
484 | { |
485 | group->asn1_form = form; |
486 | } |
487 | |
488 | point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP |
489 | *group) |
490 | { |
491 | return group->asn1_form; |
492 | } |
493 | |
494 | size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len) |
495 | { |
496 | OPENSSL_free(group->seed); |
497 | group->seed = NULL; |
498 | group->seed_len = 0; |
499 | |
500 | if (!len || !p) |
501 | return 1; |
502 | |
503 | if ((group->seed = OPENSSL_malloc(len)) == NULL) { |
504 | ECerr(EC_F_EC_GROUP_SET_SEED, ERR_R_MALLOC_FAILURE); |
505 | return 0; |
506 | } |
507 | memcpy(group->seed, p, len); |
508 | group->seed_len = len; |
509 | |
510 | return len; |
511 | } |
512 | |
513 | unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group) |
514 | { |
515 | return group->seed; |
516 | } |
517 | |
518 | size_t EC_GROUP_get_seed_len(const EC_GROUP *group) |
519 | { |
520 | return group->seed_len; |
521 | } |
522 | |
523 | int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, |
524 | const BIGNUM *b, BN_CTX *ctx) |
525 | { |
526 | if (group->meth->group_set_curve == 0) { |
527 | ECerr(EC_F_EC_GROUP_SET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
528 | return 0; |
529 | } |
530 | return group->meth->group_set_curve(group, p, a, b, ctx); |
531 | } |
532 | |
533 | int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, |
534 | BN_CTX *ctx) |
535 | { |
536 | if (group->meth->group_get_curve == NULL) { |
537 | ECerr(EC_F_EC_GROUP_GET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
538 | return 0; |
539 | } |
540 | return group->meth->group_get_curve(group, p, a, b, ctx); |
541 | } |
542 | |
543 | #ifndef OPENSSL_NO_DEPRECATED_3_0 |
544 | int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, |
545 | const BIGNUM *b, BN_CTX *ctx) |
546 | { |
547 | return EC_GROUP_set_curve(group, p, a, b, ctx); |
548 | } |
549 | |
550 | int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, |
551 | BIGNUM *b, BN_CTX *ctx) |
552 | { |
553 | return EC_GROUP_get_curve(group, p, a, b, ctx); |
554 | } |
555 | |
556 | # ifndef OPENSSL_NO_EC2M |
557 | int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a, |
558 | const BIGNUM *b, BN_CTX *ctx) |
559 | { |
560 | return EC_GROUP_set_curve(group, p, a, b, ctx); |
561 | } |
562 | |
563 | int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, |
564 | BIGNUM *b, BN_CTX *ctx) |
565 | { |
566 | return EC_GROUP_get_curve(group, p, a, b, ctx); |
567 | } |
568 | # endif |
569 | #endif |
570 | |
571 | int EC_GROUP_get_degree(const EC_GROUP *group) |
572 | { |
573 | if (group->meth->group_get_degree == 0) { |
574 | ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
575 | return 0; |
576 | } |
577 | return group->meth->group_get_degree(group); |
578 | } |
579 | |
580 | int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx) |
581 | { |
582 | if (group->meth->group_check_discriminant == 0) { |
583 | ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT, |
584 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
585 | return 0; |
586 | } |
587 | return group->meth->group_check_discriminant(group, ctx); |
588 | } |
589 | |
590 | int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx) |
591 | { |
592 | int r = 0; |
593 | BIGNUM *a1, *a2, *a3, *b1, *b2, *b3; |
594 | #ifndef FIPS_MODE |
595 | BN_CTX *ctx_new = NULL; |
596 | |
597 | if (ctx == NULL) |
598 | ctx_new = ctx = BN_CTX_new(); |
599 | #endif |
600 | if (ctx == NULL) |
601 | return -1; |
602 | |
603 | /* compare the field types */ |
604 | if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) != |
605 | EC_METHOD_get_field_type(EC_GROUP_method_of(b))) |
606 | return 1; |
607 | /* compare the curve name (if present in both) */ |
608 | if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) && |
609 | EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b)) |
610 | return 1; |
611 | if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE) |
612 | return 0; |
613 | |
614 | BN_CTX_start(ctx); |
615 | a1 = BN_CTX_get(ctx); |
616 | a2 = BN_CTX_get(ctx); |
617 | a3 = BN_CTX_get(ctx); |
618 | b1 = BN_CTX_get(ctx); |
619 | b2 = BN_CTX_get(ctx); |
620 | b3 = BN_CTX_get(ctx); |
621 | if (b3 == NULL) { |
622 | BN_CTX_end(ctx); |
623 | #ifndef FIPS_MODE |
624 | BN_CTX_free(ctx_new); |
625 | #endif |
626 | return -1; |
627 | } |
628 | |
629 | /* |
630 | * XXX This approach assumes that the external representation of curves |
631 | * over the same field type is the same. |
632 | */ |
633 | if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) || |
634 | !b->meth->group_get_curve(b, b1, b2, b3, ctx)) |
635 | r = 1; |
636 | |
637 | /* return 1 if the curve parameters are different */ |
638 | if (r || BN_cmp(a1, b1) != 0 || BN_cmp(a2, b2) != 0 || BN_cmp(a3, b3) != 0) |
639 | r = 1; |
640 | |
641 | /* XXX EC_POINT_cmp() assumes that the methods are equal */ |
642 | /* return 1 if the generators are different */ |
643 | if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a), |
644 | EC_GROUP_get0_generator(b), ctx) != 0) |
645 | r = 1; |
646 | |
647 | if (!r) { |
648 | const BIGNUM *ao, *bo, *ac, *bc; |
649 | /* compare the orders */ |
650 | ao = EC_GROUP_get0_order(a); |
651 | bo = EC_GROUP_get0_order(b); |
652 | if (ao == NULL || bo == NULL) { |
653 | /* return an error if either order is NULL */ |
654 | r = -1; |
655 | goto end; |
656 | } |
657 | if (BN_cmp(ao, bo) != 0) { |
658 | /* return 1 if orders are different */ |
659 | r = 1; |
660 | goto end; |
661 | } |
662 | /* |
663 | * It gets here if the curve parameters and generator matched. |
664 | * Now check the optional cofactors (if both are present). |
665 | */ |
666 | ac = EC_GROUP_get0_cofactor(a); |
667 | bc = EC_GROUP_get0_cofactor(b); |
668 | /* Returns 1 (mismatch) if both cofactors are specified and different */ |
669 | if (!BN_is_zero(ac) && !BN_is_zero(bc) && BN_cmp(ac, bc) != 0) |
670 | r = 1; |
671 | /* Returns 0 if the parameters matched */ |
672 | } |
673 | end: |
674 | BN_CTX_end(ctx); |
675 | #ifndef FIPS_MODE |
676 | BN_CTX_free(ctx_new); |
677 | #endif |
678 | return r; |
679 | } |
680 | |
681 | /* functions for EC_POINT objects */ |
682 | |
683 | EC_POINT *EC_POINT_new(const EC_GROUP *group) |
684 | { |
685 | EC_POINT *ret; |
686 | |
687 | if (group == NULL) { |
688 | ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER); |
689 | return NULL; |
690 | } |
691 | if (group->meth->point_init == NULL) { |
692 | ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
693 | return NULL; |
694 | } |
695 | |
696 | ret = OPENSSL_zalloc(sizeof(*ret)); |
697 | if (ret == NULL) { |
698 | ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE); |
699 | return NULL; |
700 | } |
701 | |
702 | ret->meth = group->meth; |
703 | ret->curve_name = group->curve_name; |
704 | |
705 | if (!ret->meth->point_init(ret)) { |
706 | OPENSSL_free(ret); |
707 | return NULL; |
708 | } |
709 | |
710 | return ret; |
711 | } |
712 | |
713 | void EC_POINT_free(EC_POINT *point) |
714 | { |
715 | if (point == NULL) |
716 | return; |
717 | |
718 | if (point->meth->point_finish != 0) |
719 | point->meth->point_finish(point); |
720 | OPENSSL_free(point); |
721 | } |
722 | |
723 | void EC_POINT_clear_free(EC_POINT *point) |
724 | { |
725 | if (point == NULL) |
726 | return; |
727 | |
728 | if (point->meth->point_clear_finish != 0) |
729 | point->meth->point_clear_finish(point); |
730 | else if (point->meth->point_finish != 0) |
731 | point->meth->point_finish(point); |
732 | OPENSSL_clear_free(point, sizeof(*point)); |
733 | } |
734 | |
735 | int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src) |
736 | { |
737 | if (dest->meth->point_copy == 0) { |
738 | ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
739 | return 0; |
740 | } |
741 | if (dest->meth != src->meth |
742 | || (dest->curve_name != src->curve_name |
743 | && dest->curve_name != 0 |
744 | && src->curve_name != 0)) { |
745 | ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS); |
746 | return 0; |
747 | } |
748 | if (dest == src) |
749 | return 1; |
750 | return dest->meth->point_copy(dest, src); |
751 | } |
752 | |
753 | EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group) |
754 | { |
755 | EC_POINT *t; |
756 | int r; |
757 | |
758 | if (a == NULL) |
759 | return NULL; |
760 | |
761 | t = EC_POINT_new(group); |
762 | if (t == NULL) |
763 | return NULL; |
764 | r = EC_POINT_copy(t, a); |
765 | if (!r) { |
766 | EC_POINT_free(t); |
767 | return NULL; |
768 | } |
769 | return t; |
770 | } |
771 | |
772 | const EC_METHOD *EC_POINT_method_of(const EC_POINT *point) |
773 | { |
774 | return point->meth; |
775 | } |
776 | |
777 | int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point) |
778 | { |
779 | if (group->meth->point_set_to_infinity == 0) { |
780 | ECerr(EC_F_EC_POINT_SET_TO_INFINITY, |
781 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
782 | return 0; |
783 | } |
784 | if (group->meth != point->meth) { |
785 | ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS); |
786 | return 0; |
787 | } |
788 | return group->meth->point_set_to_infinity(group, point); |
789 | } |
790 | |
791 | int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group, |
792 | EC_POINT *point, const BIGNUM *x, |
793 | const BIGNUM *y, const BIGNUM *z, |
794 | BN_CTX *ctx) |
795 | { |
796 | if (group->meth->point_set_Jprojective_coordinates_GFp == 0) { |
797 | ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP, |
798 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
799 | return 0; |
800 | } |
801 | if (!ec_point_is_compat(point, group)) { |
802 | ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP, |
803 | EC_R_INCOMPATIBLE_OBJECTS); |
804 | return 0; |
805 | } |
806 | return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x, |
807 | y, z, ctx); |
808 | } |
809 | |
810 | int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group, |
811 | const EC_POINT *point, BIGNUM *x, |
812 | BIGNUM *y, BIGNUM *z, |
813 | BN_CTX *ctx) |
814 | { |
815 | if (group->meth->point_get_Jprojective_coordinates_GFp == 0) { |
816 | ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP, |
817 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
818 | return 0; |
819 | } |
820 | if (!ec_point_is_compat(point, group)) { |
821 | ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP, |
822 | EC_R_INCOMPATIBLE_OBJECTS); |
823 | return 0; |
824 | } |
825 | return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x, |
826 | y, z, ctx); |
827 | } |
828 | |
829 | int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point, |
830 | const BIGNUM *x, const BIGNUM *y, |
831 | BN_CTX *ctx) |
832 | { |
833 | if (group->meth->point_set_affine_coordinates == NULL) { |
834 | ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, |
835 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
836 | return 0; |
837 | } |
838 | if (!ec_point_is_compat(point, group)) { |
839 | ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS); |
840 | return 0; |
841 | } |
842 | if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx)) |
843 | return 0; |
844 | |
845 | if (EC_POINT_is_on_curve(group, point, ctx) <= 0) { |
846 | ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_POINT_IS_NOT_ON_CURVE); |
847 | return 0; |
848 | } |
849 | return 1; |
850 | } |
851 | |
852 | #ifndef OPENSSL_NO_DEPRECATED_3_0 |
853 | int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, |
854 | EC_POINT *point, const BIGNUM *x, |
855 | const BIGNUM *y, BN_CTX *ctx) |
856 | { |
857 | return EC_POINT_set_affine_coordinates(group, point, x, y, ctx); |
858 | } |
859 | |
860 | # ifndef OPENSSL_NO_EC2M |
861 | int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, |
862 | EC_POINT *point, const BIGNUM *x, |
863 | const BIGNUM *y, BN_CTX *ctx) |
864 | { |
865 | return EC_POINT_set_affine_coordinates(group, point, x, y, ctx); |
866 | } |
867 | # endif |
868 | #endif |
869 | |
870 | int EC_POINT_get_affine_coordinates(const EC_GROUP *group, |
871 | const EC_POINT *point, BIGNUM *x, BIGNUM *y, |
872 | BN_CTX *ctx) |
873 | { |
874 | if (group->meth->point_get_affine_coordinates == NULL) { |
875 | ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, |
876 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
877 | return 0; |
878 | } |
879 | if (!ec_point_is_compat(point, group)) { |
880 | ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS); |
881 | return 0; |
882 | } |
883 | if (EC_POINT_is_at_infinity(group, point)) { |
884 | ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY); |
885 | return 0; |
886 | } |
887 | return group->meth->point_get_affine_coordinates(group, point, x, y, ctx); |
888 | } |
889 | |
890 | #ifndef OPENSSL_NO_DEPRECATED_3_0 |
891 | int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group, |
892 | const EC_POINT *point, BIGNUM *x, |
893 | BIGNUM *y, BN_CTX *ctx) |
894 | { |
895 | return EC_POINT_get_affine_coordinates(group, point, x, y, ctx); |
896 | } |
897 | |
898 | # ifndef OPENSSL_NO_EC2M |
899 | int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group, |
900 | const EC_POINT *point, BIGNUM *x, |
901 | BIGNUM *y, BN_CTX *ctx) |
902 | { |
903 | return EC_POINT_get_affine_coordinates(group, point, x, y, ctx); |
904 | } |
905 | # endif |
906 | #endif |
907 | |
908 | int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, |
909 | const EC_POINT *b, BN_CTX *ctx) |
910 | { |
911 | if (group->meth->add == 0) { |
912 | ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
913 | return 0; |
914 | } |
915 | if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group) |
916 | || !ec_point_is_compat(b, group)) { |
917 | ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS); |
918 | return 0; |
919 | } |
920 | return group->meth->add(group, r, a, b, ctx); |
921 | } |
922 | |
923 | int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, |
924 | BN_CTX *ctx) |
925 | { |
926 | if (group->meth->dbl == 0) { |
927 | ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
928 | return 0; |
929 | } |
930 | if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) { |
931 | ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS); |
932 | return 0; |
933 | } |
934 | return group->meth->dbl(group, r, a, ctx); |
935 | } |
936 | |
937 | int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx) |
938 | { |
939 | if (group->meth->invert == 0) { |
940 | ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
941 | return 0; |
942 | } |
943 | if (!ec_point_is_compat(a, group)) { |
944 | ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS); |
945 | return 0; |
946 | } |
947 | return group->meth->invert(group, a, ctx); |
948 | } |
949 | |
950 | int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point) |
951 | { |
952 | if (group->meth->is_at_infinity == 0) { |
953 | ECerr(EC_F_EC_POINT_IS_AT_INFINITY, |
954 | ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
955 | return 0; |
956 | } |
957 | if (!ec_point_is_compat(point, group)) { |
958 | ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS); |
959 | return 0; |
960 | } |
961 | return group->meth->is_at_infinity(group, point); |
962 | } |
963 | |
964 | /* |
965 | * Check whether an EC_POINT is on the curve or not. Note that the return |
966 | * value for this function should NOT be treated as a boolean. Return values: |
967 | * 1: The point is on the curve |
968 | * 0: The point is not on the curve |
969 | * -1: An error occurred |
970 | */ |
971 | int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point, |
972 | BN_CTX *ctx) |
973 | { |
974 | if (group->meth->is_on_curve == 0) { |
975 | ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
976 | return 0; |
977 | } |
978 | if (!ec_point_is_compat(point, group)) { |
979 | ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS); |
980 | return 0; |
981 | } |
982 | return group->meth->is_on_curve(group, point, ctx); |
983 | } |
984 | |
985 | int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, |
986 | BN_CTX *ctx) |
987 | { |
988 | if (group->meth->point_cmp == 0) { |
989 | ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
990 | return -1; |
991 | } |
992 | if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) { |
993 | ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS); |
994 | return -1; |
995 | } |
996 | return group->meth->point_cmp(group, a, b, ctx); |
997 | } |
998 | |
999 | int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx) |
1000 | { |
1001 | if (group->meth->make_affine == 0) { |
1002 | ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
1003 | return 0; |
1004 | } |
1005 | if (!ec_point_is_compat(point, group)) { |
1006 | ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS); |
1007 | return 0; |
1008 | } |
1009 | return group->meth->make_affine(group, point, ctx); |
1010 | } |
1011 | |
1012 | int EC_POINTs_make_affine(const EC_GROUP *group, size_t num, |
1013 | EC_POINT *points[], BN_CTX *ctx) |
1014 | { |
1015 | size_t i; |
1016 | |
1017 | if (group->meth->points_make_affine == 0) { |
1018 | ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
1019 | return 0; |
1020 | } |
1021 | for (i = 0; i < num; i++) { |
1022 | if (!ec_point_is_compat(points[i], group)) { |
1023 | ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS); |
1024 | return 0; |
1025 | } |
1026 | } |
1027 | return group->meth->points_make_affine(group, num, points, ctx); |
1028 | } |
1029 | |
1030 | /* |
1031 | * Functions for point multiplication. If group->meth->mul is 0, we use the |
1032 | * wNAF-based implementations in ec_mult.c; otherwise we dispatch through |
1033 | * methods. |
1034 | */ |
1035 | |
1036 | int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar, |
1037 | size_t num, const EC_POINT *points[], |
1038 | const BIGNUM *scalars[], BN_CTX *ctx) |
1039 | { |
1040 | int ret = 0; |
1041 | size_t i = 0; |
1042 | #ifndef FIPS_MODE |
1043 | BN_CTX *new_ctx = NULL; |
1044 | |
1045 | if (ctx == NULL) |
1046 | ctx = new_ctx = BN_CTX_secure_new(); |
1047 | #endif |
1048 | if (ctx == NULL) { |
1049 | ECerr(EC_F_EC_POINTS_MUL, ERR_R_INTERNAL_ERROR); |
1050 | return 0; |
1051 | } |
1052 | |
1053 | if ((scalar == NULL) && (num == 0)) { |
1054 | return EC_POINT_set_to_infinity(group, r); |
1055 | } |
1056 | |
1057 | if (!ec_point_is_compat(r, group)) { |
1058 | ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
1059 | return 0; |
1060 | } |
1061 | for (i = 0; i < num; i++) { |
1062 | if (!ec_point_is_compat(points[i], group)) { |
1063 | ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS); |
1064 | return 0; |
1065 | } |
1066 | } |
1067 | |
1068 | if (group->meth->mul != NULL) |
1069 | ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx); |
1070 | else |
1071 | /* use default */ |
1072 | ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx); |
1073 | |
1074 | #ifndef FIPS_MODE |
1075 | BN_CTX_free(new_ctx); |
1076 | #endif |
1077 | return ret; |
1078 | } |
1079 | |
1080 | int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar, |
1081 | const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx) |
1082 | { |
1083 | /* just a convenient interface to EC_POINTs_mul() */ |
1084 | |
1085 | const EC_POINT *points[1]; |
1086 | const BIGNUM *scalars[1]; |
1087 | |
1088 | points[0] = point; |
1089 | scalars[0] = p_scalar; |
1090 | |
1091 | return EC_POINTs_mul(group, r, g_scalar, |
1092 | (point != NULL |
1093 | && p_scalar != NULL), points, scalars, ctx); |
1094 | } |
1095 | |
1096 | int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx) |
1097 | { |
1098 | if (group->meth->mul == 0) |
1099 | /* use default */ |
1100 | return ec_wNAF_precompute_mult(group, ctx); |
1101 | |
1102 | if (group->meth->precompute_mult != 0) |
1103 | return group->meth->precompute_mult(group, ctx); |
1104 | else |
1105 | return 1; /* nothing to do, so report success */ |
1106 | } |
1107 | |
1108 | int EC_GROUP_have_precompute_mult(const EC_GROUP *group) |
1109 | { |
1110 | if (group->meth->mul == 0) |
1111 | /* use default */ |
1112 | return ec_wNAF_have_precompute_mult(group); |
1113 | |
1114 | if (group->meth->have_precompute_mult != 0) |
1115 | return group->meth->have_precompute_mult(group); |
1116 | else |
1117 | return 0; /* cannot tell whether precomputation has |
1118 | * been performed */ |
1119 | } |
1120 | |
1121 | /* |
1122 | * ec_precompute_mont_data sets |group->mont_data| from |group->order| and |
1123 | * returns one on success. On error it returns zero. |
1124 | */ |
1125 | static int ec_precompute_mont_data(EC_GROUP *group) |
1126 | { |
1127 | BN_CTX *ctx = BN_CTX_new_ex(group->libctx); |
1128 | int ret = 0; |
1129 | |
1130 | BN_MONT_CTX_free(group->mont_data); |
1131 | group->mont_data = NULL; |
1132 | |
1133 | if (ctx == NULL) |
1134 | goto err; |
1135 | |
1136 | group->mont_data = BN_MONT_CTX_new(); |
1137 | if (group->mont_data == NULL) |
1138 | goto err; |
1139 | |
1140 | if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) { |
1141 | BN_MONT_CTX_free(group->mont_data); |
1142 | group->mont_data = NULL; |
1143 | goto err; |
1144 | } |
1145 | |
1146 | ret = 1; |
1147 | |
1148 | err: |
1149 | |
1150 | BN_CTX_free(ctx); |
1151 | return ret; |
1152 | } |
1153 | |
1154 | #ifndef FIPS_MODE |
1155 | int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg) |
1156 | { |
1157 | return CRYPTO_set_ex_data(&key->ex_data, idx, arg); |
1158 | } |
1159 | |
1160 | void *EC_KEY_get_ex_data(const EC_KEY *key, int idx) |
1161 | { |
1162 | return CRYPTO_get_ex_data(&key->ex_data, idx); |
1163 | } |
1164 | #endif |
1165 | |
1166 | int ec_group_simple_order_bits(const EC_GROUP *group) |
1167 | { |
1168 | if (group->order == NULL) |
1169 | return 0; |
1170 | return BN_num_bits(group->order); |
1171 | } |
1172 | |
1173 | static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r, |
1174 | const BIGNUM *x, BN_CTX *ctx) |
1175 | { |
1176 | BIGNUM *e = NULL; |
1177 | int ret = 0; |
1178 | #ifndef FIPS_MODE |
1179 | BN_CTX *new_ctx = NULL; |
1180 | |
1181 | if (ctx == NULL) |
1182 | ctx = new_ctx = BN_CTX_secure_new(); |
1183 | #endif |
1184 | if (ctx == NULL) |
1185 | return 0; |
1186 | |
1187 | if (group->mont_data == NULL) |
1188 | goto err; |
1189 | |
1190 | BN_CTX_start(ctx); |
1191 | if ((e = BN_CTX_get(ctx)) == NULL) |
1192 | goto err; |
1193 | |
1194 | /*- |
1195 | * We want inverse in constant time, therefore we utilize the fact |
1196 | * order must be prime and use Fermats Little Theorem instead. |
1197 | */ |
1198 | if (!BN_set_word(e, 2)) |
1199 | goto err; |
1200 | if (!BN_sub(e, group->order, e)) |
1201 | goto err; |
1202 | /*- |
1203 | * Exponent e is public. |
1204 | * No need for scatter-gather or BN_FLG_CONSTTIME. |
1205 | */ |
1206 | if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data)) |
1207 | goto err; |
1208 | |
1209 | ret = 1; |
1210 | |
1211 | err: |
1212 | BN_CTX_end(ctx); |
1213 | #ifndef FIPS_MODE |
1214 | BN_CTX_free(new_ctx); |
1215 | #endif |
1216 | return ret; |
1217 | } |
1218 | |
1219 | /*- |
1220 | * Default behavior, if group->meth->field_inverse_mod_ord is NULL: |
1221 | * - When group->order is even, this function returns an error. |
1222 | * - When group->order is otherwise composite, the correctness |
1223 | * of the output is not guaranteed. |
1224 | * - When x is outside the range [1, group->order), the correctness |
1225 | * of the output is not guaranteed. |
1226 | * - Otherwise, this function returns the multiplicative inverse in the |
1227 | * range [1, group->order). |
1228 | * |
1229 | * EC_METHODs must implement their own field_inverse_mod_ord for |
1230 | * other functionality. |
1231 | */ |
1232 | int ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res, |
1233 | const BIGNUM *x, BN_CTX *ctx) |
1234 | { |
1235 | if (group->meth->field_inverse_mod_ord != NULL) |
1236 | return group->meth->field_inverse_mod_ord(group, res, x, ctx); |
1237 | else |
1238 | return ec_field_inverse_mod_ord(group, res, x, ctx); |
1239 | } |
1240 | |
1241 | /*- |
1242 | * Coordinate blinding for EC_POINT. |
1243 | * |
1244 | * The underlying EC_METHOD can optionally implement this function: |
1245 | * underlying implementations should return 0 on errors, or 1 on |
1246 | * success. |
1247 | * |
1248 | * This wrapper returns 1 in case the underlying EC_METHOD does not |
1249 | * support coordinate blinding. |
1250 | */ |
1251 | int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx) |
1252 | { |
1253 | if (group->meth->blind_coordinates == NULL) |
1254 | return 1; /* ignore if not implemented */ |
1255 | |
1256 | return group->meth->blind_coordinates(group, p, ctx); |
1257 | } |
1258 | |