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
20EC_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
63EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
64{
65 return EC_GROUP_new_ex(NULL, meth);
66}
67#endif
68
69void 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
102void 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
120void 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
140int 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
244EC_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
267const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
268{
269 return group->meth;
270}
271
272int EC_METHOD_get_field_type(const EC_METHOD *meth)
273{
274 return meth->field_type;
275}
276
277static 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 */
292static 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
340int 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
410const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
411{
412 return group->generator;
413}
414
415BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
416{
417 return group->mont_data;
418}
419
420int 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
430const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group)
431{
432 return group->order;
433}
434
435int EC_GROUP_order_bits(const EC_GROUP *group)
436{
437 return group->meth->group_order_bits(group);
438}
439
440int 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
452const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group)
453{
454 return group->cofactor;
455}
456
457void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
458{
459 group->curve_name = nid;
460}
461
462int EC_GROUP_get_curve_name(const EC_GROUP *group)
463{
464 return group->curve_name;
465}
466
467const BIGNUM *EC_GROUP_get0_field(const EC_GROUP *group)
468{
469 return group->field;
470}
471
472void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
473{
474 group->asn1_flag = flag;
475}
476
477int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
478{
479 return group->asn1_flag;
480}
481
482void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
483 point_conversion_form_t form)
484{
485 group->asn1_form = form;
486}
487
488point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
489 *group)
490{
491 return group->asn1_form;
492}
493
494size_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
513unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
514{
515 return group->seed;
516}
517
518size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
519{
520 return group->seed_len;
521}
522
523int 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
533int 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
544int 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
550int 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
557int 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
563int 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
571int 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
580int 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
590int 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 }
673end:
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
683EC_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
713void 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
723void 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
735int 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
753EC_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
772const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
773{
774 return point->meth;
775}
776
777int 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
791int 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
810int 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
829int 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
853int 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
861int 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
870int 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
891int 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
899int 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
908int 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
923int 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
937int 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
950int 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 */
971int 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
985int 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
999int 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
1012int 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
1036int 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
1080int 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
1096int 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
1108int 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 */
1125static 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
1155int 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
1160void *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
1166int 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
1173static 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 */
1232int 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 */
1251int 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