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source: vbox/trunk/src/libs/openssl-3.0.7/crypto/ec/ec_lib.c@ 98227

Last change on this file since 98227 was 97372, checked in by vboxsync, 2 years ago

libs: Switch to openssl-3.0.7, bugref:10317
File size: 49.5 KB
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1/*
2 * Copyright 2001-2022 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/*
12 * EC_GROUP low level APIs are deprecated for public use, but still ok for
13 * internal use.
14 */
15#include "internal/deprecated.h"
16
17#include <string.h>
18#include <openssl/params.h>
19#include <openssl/core_names.h>
20#include <openssl/err.h>
21#include <openssl/opensslv.h>
22#include "crypto/ec.h"
23#include "internal/nelem.h"
24#include "ec_local.h"
25
26/* functions for EC_GROUP objects */
27
28EC_GROUP *ossl_ec_group_new_ex(OSSL_LIB_CTX *libctx, const char *propq,
29 const EC_METHOD *meth)
30{
31 EC_GROUP *ret;
32
33 if (meth == NULL) {
34 ERR_raise(ERR_LIB_EC, EC_R_SLOT_FULL);
35 return NULL;
36 }
37 if (meth->group_init == 0) {
38 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
39 return NULL;
40 }
41
42 ret = OPENSSL_zalloc(sizeof(*ret));
43 if (ret == NULL) {
44 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
45 return NULL;
46 }
47
48 ret->libctx = libctx;
49 if (propq != NULL) {
50 ret->propq = OPENSSL_strdup(propq);
51 if (ret->propq == NULL) {
52 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
53 goto err;
54 }
55 }
56 ret->meth = meth;
57 if ((ret->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
58 ret->order = BN_new();
59 if (ret->order == NULL)
60 goto err;
61 ret->cofactor = BN_new();
62 if (ret->cofactor == NULL)
63 goto err;
64 }
65 ret->asn1_flag = OPENSSL_EC_EXPLICIT_CURVE;
66 ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED;
67 if (!meth->group_init(ret))
68 goto err;
69 return ret;
70
71 err:
72 BN_free(ret->order);
73 BN_free(ret->cofactor);
74 OPENSSL_free(ret->propq);
75 OPENSSL_free(ret);
76 return NULL;
77}
78
79#ifndef OPENSSL_NO_DEPRECATED_3_0
80# ifndef FIPS_MODULE
81EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
82{
83 return ossl_ec_group_new_ex(NULL, NULL, meth);
84}
85# endif
86#endif
87
88void EC_pre_comp_free(EC_GROUP *group)
89{
90 switch (group->pre_comp_type) {
91 case PCT_none:
92 break;
93 case PCT_nistz256:
94#ifdef ECP_NISTZ256_ASM
95 EC_nistz256_pre_comp_free(group->pre_comp.nistz256);
96#endif
97 break;
98#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
99 case PCT_nistp224:
100 EC_nistp224_pre_comp_free(group->pre_comp.nistp224);
101 break;
102 case PCT_nistp256:
103 EC_nistp256_pre_comp_free(group->pre_comp.nistp256);
104 break;
105 case PCT_nistp521:
106 EC_nistp521_pre_comp_free(group->pre_comp.nistp521);
107 break;
108#else
109 case PCT_nistp224:
110 case PCT_nistp256:
111 case PCT_nistp521:
112 break;
113#endif
114 case PCT_ec:
115 EC_ec_pre_comp_free(group->pre_comp.ec);
116 break;
117 }
118 group->pre_comp.ec = NULL;
119}
120
121void EC_GROUP_free(EC_GROUP *group)
122{
123 if (!group)
124 return;
125
126 if (group->meth->group_finish != 0)
127 group->meth->group_finish(group);
128
129 EC_pre_comp_free(group);
130 BN_MONT_CTX_free(group->mont_data);
131 EC_POINT_free(group->generator);
132 BN_free(group->order);
133 BN_free(group->cofactor);
134 OPENSSL_free(group->seed);
135 OPENSSL_free(group->propq);
136 OPENSSL_free(group);
137}
138
139#ifndef OPENSSL_NO_DEPRECATED_3_0
140void EC_GROUP_clear_free(EC_GROUP *group)
141{
142 if (!group)
143 return;
144
145 if (group->meth->group_clear_finish != 0)
146 group->meth->group_clear_finish(group);
147 else if (group->meth->group_finish != 0)
148 group->meth->group_finish(group);
149
150 EC_pre_comp_free(group);
151 BN_MONT_CTX_free(group->mont_data);
152 EC_POINT_clear_free(group->generator);
153 BN_clear_free(group->order);
154 BN_clear_free(group->cofactor);
155 OPENSSL_clear_free(group->seed, group->seed_len);
156 OPENSSL_clear_free(group, sizeof(*group));
157}
158#endif
159
160int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
161{
162 if (dest->meth->group_copy == 0) {
163 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
164 return 0;
165 }
166 if (dest->meth != src->meth) {
167 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
168 return 0;
169 }
170 if (dest == src)
171 return 1;
172
173 dest->libctx = src->libctx;
174 dest->curve_name = src->curve_name;
175
176 /* Copy precomputed */
177 dest->pre_comp_type = src->pre_comp_type;
178 switch (src->pre_comp_type) {
179 case PCT_none:
180 dest->pre_comp.ec = NULL;
181 break;
182 case PCT_nistz256:
183#ifdef ECP_NISTZ256_ASM
184 dest->pre_comp.nistz256 = EC_nistz256_pre_comp_dup(src->pre_comp.nistz256);
185#endif
186 break;
187#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
188 case PCT_nistp224:
189 dest->pre_comp.nistp224 = EC_nistp224_pre_comp_dup(src->pre_comp.nistp224);
190 break;
191 case PCT_nistp256:
192 dest->pre_comp.nistp256 = EC_nistp256_pre_comp_dup(src->pre_comp.nistp256);
193 break;
194 case PCT_nistp521:
195 dest->pre_comp.nistp521 = EC_nistp521_pre_comp_dup(src->pre_comp.nistp521);
196 break;
197#else
198 case PCT_nistp224:
199 case PCT_nistp256:
200 case PCT_nistp521:
201 break;
202#endif
203 case PCT_ec:
204 dest->pre_comp.ec = EC_ec_pre_comp_dup(src->pre_comp.ec);
205 break;
206 }
207
208 if (src->mont_data != NULL) {
209 if (dest->mont_data == NULL) {
210 dest->mont_data = BN_MONT_CTX_new();
211 if (dest->mont_data == NULL)
212 return 0;
213 }
214 if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data))
215 return 0;
216 } else {
217 /* src->generator == NULL */
218 BN_MONT_CTX_free(dest->mont_data);
219 dest->mont_data = NULL;
220 }
221
222 if (src->generator != NULL) {
223 if (dest->generator == NULL) {
224 dest->generator = EC_POINT_new(dest);
225 if (dest->generator == NULL)
226 return 0;
227 }
228 if (!EC_POINT_copy(dest->generator, src->generator))
229 return 0;
230 } else {
231 /* src->generator == NULL */
232 EC_POINT_clear_free(dest->generator);
233 dest->generator = NULL;
234 }
235
236 if ((src->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
237 if (!BN_copy(dest->order, src->order))
238 return 0;
239 if (!BN_copy(dest->cofactor, src->cofactor))
240 return 0;
241 }
242
243 dest->asn1_flag = src->asn1_flag;
244 dest->asn1_form = src->asn1_form;
245 dest->decoded_from_explicit_params = src->decoded_from_explicit_params;
246
247 if (src->seed) {
248 OPENSSL_free(dest->seed);
249 if ((dest->seed = OPENSSL_malloc(src->seed_len)) == NULL) {
250 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
251 return 0;
252 }
253 if (!memcpy(dest->seed, src->seed, src->seed_len))
254 return 0;
255 dest->seed_len = src->seed_len;
256 } else {
257 OPENSSL_free(dest->seed);
258 dest->seed = NULL;
259 dest->seed_len = 0;
260 }
261
262 return dest->meth->group_copy(dest, src);
263}
264
265EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
266{
267 EC_GROUP *t = NULL;
268 int ok = 0;
269
270 if (a == NULL)
271 return NULL;
272
273 if ((t = ossl_ec_group_new_ex(a->libctx, a->propq, a->meth)) == NULL)
274 return NULL;
275 if (!EC_GROUP_copy(t, a))
276 goto err;
277
278 ok = 1;
279
280 err:
281 if (!ok) {
282 EC_GROUP_free(t);
283 return NULL;
284 }
285 return t;
286}
287
288#ifndef OPENSSL_NO_DEPRECATED_3_0
289const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
290{
291 return group->meth;
292}
293
294int EC_METHOD_get_field_type(const EC_METHOD *meth)
295{
296 return meth->field_type;
297}
298#endif
299
300static int ec_precompute_mont_data(EC_GROUP *);
301
302/*-
303 * Try computing cofactor from the generator order (n) and field cardinality (q).
304 * This works for all curves of cryptographic interest.
305 *
306 * Hasse thm: q + 1 - 2*sqrt(q) <= n*h <= q + 1 + 2*sqrt(q)
307 * h_min = (q + 1 - 2*sqrt(q))/n
308 * h_max = (q + 1 + 2*sqrt(q))/n
309 * h_max - h_min = 4*sqrt(q)/n
310 * So if n > 4*sqrt(q) holds, there is only one possible value for h:
311 * h = \lfloor (h_min + h_max)/2 \rceil = \lfloor (q + 1)/n \rceil
312 *
313 * Otherwise, zero cofactor and return success.
314 */
315static int ec_guess_cofactor(EC_GROUP *group) {
316 int ret = 0;
317 BN_CTX *ctx = NULL;
318 BIGNUM *q = NULL;
319
320 /*-
321 * If the cofactor is too large, we cannot guess it.
322 * The RHS of below is a strict overestimate of lg(4 * sqrt(q))
323 */
324 if (BN_num_bits(group->order) <= (BN_num_bits(group->field) + 1) / 2 + 3) {
325 /* default to 0 */
326 BN_zero(group->cofactor);
327 /* return success */
328 return 1;
329 }
330
331 if ((ctx = BN_CTX_new_ex(group->libctx)) == NULL)
332 return 0;
333
334 BN_CTX_start(ctx);
335 if ((q = BN_CTX_get(ctx)) == NULL)
336 goto err;
337
338 /* set q = 2**m for binary fields; q = p otherwise */
339 if (group->meth->field_type == NID_X9_62_characteristic_two_field) {
340 BN_zero(q);
341 if (!BN_set_bit(q, BN_num_bits(group->field) - 1))
342 goto err;
343 } else {
344 if (!BN_copy(q, group->field))
345 goto err;
346 }
347
348 /* compute h = \lfloor (q + 1)/n \rceil = \lfloor (q + 1 + n/2)/n \rfloor */
349 if (!BN_rshift1(group->cofactor, group->order) /* n/2 */
350 || !BN_add(group->cofactor, group->cofactor, q) /* q + n/2 */
351 /* q + 1 + n/2 */
352 || !BN_add(group->cofactor, group->cofactor, BN_value_one())
353 /* (q + 1 + n/2)/n */
354 || !BN_div(group->cofactor, NULL, group->cofactor, group->order, ctx))
355 goto err;
356 ret = 1;
357 err:
358 BN_CTX_end(ctx);
359 BN_CTX_free(ctx);
360 return ret;
361}
362
363int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
364 const BIGNUM *order, const BIGNUM *cofactor)
365{
366 if (generator == NULL) {
367 ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);
368 return 0;
369 }
370
371 /* require group->field >= 1 */
372 if (group->field == NULL || BN_is_zero(group->field)
373 || BN_is_negative(group->field)) {
374 ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD);
375 return 0;
376 }
377
378 /*-
379 * - require order >= 1
380 * - enforce upper bound due to Hasse thm: order can be no more than one bit
381 * longer than field cardinality
382 */
383 if (order == NULL || BN_is_zero(order) || BN_is_negative(order)
384 || BN_num_bits(order) > BN_num_bits(group->field) + 1) {
385 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER);
386 return 0;
387 }
388
389 /*-
390 * Unfortunately the cofactor is an optional field in many standards.
391 * Internally, the lib uses 0 cofactor as a marker for "unknown cofactor".
392 * So accept cofactor == NULL or cofactor >= 0.
393 */
394 if (cofactor != NULL && BN_is_negative(cofactor)) {
395 ERR_raise(ERR_LIB_EC, EC_R_UNKNOWN_COFACTOR);
396 return 0;
397 }
398
399 if (group->generator == NULL) {
400 group->generator = EC_POINT_new(group);
401 if (group->generator == NULL)
402 return 0;
403 }
404 if (!EC_POINT_copy(group->generator, generator))
405 return 0;
406
407 if (!BN_copy(group->order, order))
408 return 0;
409
410 /* Either take the provided positive cofactor, or try to compute it */
411 if (cofactor != NULL && !BN_is_zero(cofactor)) {
412 if (!BN_copy(group->cofactor, cofactor))
413 return 0;
414 } else if (!ec_guess_cofactor(group)) {
415 BN_zero(group->cofactor);
416 return 0;
417 }
418
419 /*
420 * Some groups have an order with
421 * factors of two, which makes the Montgomery setup fail.
422 * |group->mont_data| will be NULL in this case.
423 */
424 if (BN_is_odd(group->order)) {
425 return ec_precompute_mont_data(group);
426 }
427
428 BN_MONT_CTX_free(group->mont_data);
429 group->mont_data = NULL;
430 return 1;
431}
432
433const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
434{
435 return group->generator;
436}
437
438BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
439{
440 return group->mont_data;
441}
442
443int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
444{
445 if (group->order == NULL)
446 return 0;
447 if (!BN_copy(order, group->order))
448 return 0;
449
450 return !BN_is_zero(order);
451}
452
453const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group)
454{
455 return group->order;
456}
457
458int EC_GROUP_order_bits(const EC_GROUP *group)
459{
460 return group->meth->group_order_bits(group);
461}
462
463int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
464 BN_CTX *ctx)
465{
466
467 if (group->cofactor == NULL)
468 return 0;
469 if (!BN_copy(cofactor, group->cofactor))
470 return 0;
471
472 return !BN_is_zero(group->cofactor);
473}
474
475const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group)
476{
477 return group->cofactor;
478}
479
480void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
481{
482 group->curve_name = nid;
483 group->asn1_flag =
484 (nid != NID_undef)
485 ? OPENSSL_EC_NAMED_CURVE
486 : OPENSSL_EC_EXPLICIT_CURVE;
487}
488
489int EC_GROUP_get_curve_name(const EC_GROUP *group)
490{
491 return group->curve_name;
492}
493
494const BIGNUM *EC_GROUP_get0_field(const EC_GROUP *group)
495{
496 return group->field;
497}
498
499int EC_GROUP_get_field_type(const EC_GROUP *group)
500{
501 return group->meth->field_type;
502}
503
504void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
505{
506 group->asn1_flag = flag;
507}
508
509int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
510{
511 return group->asn1_flag;
512}
513
514void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
515 point_conversion_form_t form)
516{
517 group->asn1_form = form;
518}
519
520point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
521 *group)
522{
523 return group->asn1_form;
524}
525
526size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
527{
528 OPENSSL_free(group->seed);
529 group->seed = NULL;
530 group->seed_len = 0;
531
532 if (!len || !p)
533 return 1;
534
535 if ((group->seed = OPENSSL_malloc(len)) == NULL) {
536 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
537 return 0;
538 }
539 memcpy(group->seed, p, len);
540 group->seed_len = len;
541
542 return len;
543}
544
545unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
546{
547 return group->seed;
548}
549
550size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
551{
552 return group->seed_len;
553}
554
555int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
556 const BIGNUM *b, BN_CTX *ctx)
557{
558 if (group->meth->group_set_curve == 0) {
559 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
560 return 0;
561 }
562 return group->meth->group_set_curve(group, p, a, b, ctx);
563}
564
565int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b,
566 BN_CTX *ctx)
567{
568 if (group->meth->group_get_curve == NULL) {
569 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
570 return 0;
571 }
572 return group->meth->group_get_curve(group, p, a, b, ctx);
573}
574
575#ifndef OPENSSL_NO_DEPRECATED_3_0
576int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
577 const BIGNUM *b, BN_CTX *ctx)
578{
579 return EC_GROUP_set_curve(group, p, a, b, ctx);
580}
581
582int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
583 BIGNUM *b, BN_CTX *ctx)
584{
585 return EC_GROUP_get_curve(group, p, a, b, ctx);
586}
587
588# ifndef OPENSSL_NO_EC2M
589int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
590 const BIGNUM *b, BN_CTX *ctx)
591{
592 return EC_GROUP_set_curve(group, p, a, b, ctx);
593}
594
595int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
596 BIGNUM *b, BN_CTX *ctx)
597{
598 return EC_GROUP_get_curve(group, p, a, b, ctx);
599}
600# endif
601#endif
602
603int EC_GROUP_get_degree(const EC_GROUP *group)
604{
605 if (group->meth->group_get_degree == 0) {
606 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
607 return 0;
608 }
609 return group->meth->group_get_degree(group);
610}
611
612int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
613{
614 if (group->meth->group_check_discriminant == 0) {
615 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
616 return 0;
617 }
618 return group->meth->group_check_discriminant(group, ctx);
619}
620
621int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
622{
623 int r = 0;
624 BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
625#ifndef FIPS_MODULE
626 BN_CTX *ctx_new = NULL;
627#endif
628
629 /* compare the field types */
630 if (EC_GROUP_get_field_type(a) != EC_GROUP_get_field_type(b))
631 return 1;
632 /* compare the curve name (if present in both) */
633 if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
634 EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
635 return 1;
636 if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE)
637 return 0;
638
639#ifndef FIPS_MODULE
640 if (ctx == NULL)
641 ctx_new = ctx = BN_CTX_new();
642#endif
643 if (ctx == NULL)
644 return -1;
645
646 BN_CTX_start(ctx);
647 a1 = BN_CTX_get(ctx);
648 a2 = BN_CTX_get(ctx);
649 a3 = BN_CTX_get(ctx);
650 b1 = BN_CTX_get(ctx);
651 b2 = BN_CTX_get(ctx);
652 b3 = BN_CTX_get(ctx);
653 if (b3 == NULL) {
654 BN_CTX_end(ctx);
655#ifndef FIPS_MODULE
656 BN_CTX_free(ctx_new);
657#endif
658 return -1;
659 }
660
661 /*
662 * XXX This approach assumes that the external representation of curves
663 * over the same field type is the same.
664 */
665 if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
666 !b->meth->group_get_curve(b, b1, b2, b3, ctx))
667 r = 1;
668
669 /* return 1 if the curve parameters are different */
670 if (r || BN_cmp(a1, b1) != 0 || BN_cmp(a2, b2) != 0 || BN_cmp(a3, b3) != 0)
671 r = 1;
672
673 /* XXX EC_POINT_cmp() assumes that the methods are equal */
674 /* return 1 if the generators are different */
675 if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
676 EC_GROUP_get0_generator(b), ctx) != 0)
677 r = 1;
678
679 if (!r) {
680 const BIGNUM *ao, *bo, *ac, *bc;
681 /* compare the orders */
682 ao = EC_GROUP_get0_order(a);
683 bo = EC_GROUP_get0_order(b);
684 if (ao == NULL || bo == NULL) {
685 /* return an error if either order is NULL */
686 r = -1;
687 goto end;
688 }
689 if (BN_cmp(ao, bo) != 0) {
690 /* return 1 if orders are different */
691 r = 1;
692 goto end;
693 }
694 /*
695 * It gets here if the curve parameters and generator matched.
696 * Now check the optional cofactors (if both are present).
697 */
698 ac = EC_GROUP_get0_cofactor(a);
699 bc = EC_GROUP_get0_cofactor(b);
700 /* Returns 1 (mismatch) if both cofactors are specified and different */
701 if (!BN_is_zero(ac) && !BN_is_zero(bc) && BN_cmp(ac, bc) != 0)
702 r = 1;
703 /* Returns 0 if the parameters matched */
704 }
705end:
706 BN_CTX_end(ctx);
707#ifndef FIPS_MODULE
708 BN_CTX_free(ctx_new);
709#endif
710 return r;
711}
712
713/* functions for EC_POINT objects */
714
715EC_POINT *EC_POINT_new(const EC_GROUP *group)
716{
717 EC_POINT *ret;
718
719 if (group == NULL) {
720 ERR_raise(ERR_LIB_EC, ERR_R_PASSED_NULL_PARAMETER);
721 return NULL;
722 }
723 if (group->meth->point_init == NULL) {
724 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
725 return NULL;
726 }
727
728 ret = OPENSSL_zalloc(sizeof(*ret));
729 if (ret == NULL) {
730 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
731 return NULL;
732 }
733
734 ret->meth = group->meth;
735 ret->curve_name = group->curve_name;
736
737 if (!ret->meth->point_init(ret)) {
738 OPENSSL_free(ret);
739 return NULL;
740 }
741
742 return ret;
743}
744
745void EC_POINT_free(EC_POINT *point)
746{
747 if (point == NULL)
748 return;
749
750 if (point->meth->point_finish != 0)
751 point->meth->point_finish(point);
752 OPENSSL_free(point);
753}
754
755void EC_POINT_clear_free(EC_POINT *point)
756{
757 if (point == NULL)
758 return;
759
760 if (point->meth->point_clear_finish != 0)
761 point->meth->point_clear_finish(point);
762 else if (point->meth->point_finish != 0)
763 point->meth->point_finish(point);
764 OPENSSL_clear_free(point, sizeof(*point));
765}
766
767int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
768{
769 if (dest->meth->point_copy == 0) {
770 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
771 return 0;
772 }
773 if (dest->meth != src->meth
774 || (dest->curve_name != src->curve_name
775 && dest->curve_name != 0
776 && src->curve_name != 0)) {
777 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
778 return 0;
779 }
780 if (dest == src)
781 return 1;
782 return dest->meth->point_copy(dest, src);
783}
784
785EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
786{
787 EC_POINT *t;
788 int r;
789
790 if (a == NULL)
791 return NULL;
792
793 t = EC_POINT_new(group);
794 if (t == NULL)
795 return NULL;
796 r = EC_POINT_copy(t, a);
797 if (!r) {
798 EC_POINT_free(t);
799 return NULL;
800 }
801 return t;
802}
803
804#ifndef OPENSSL_NO_DEPRECATED_3_0
805const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
806{
807 return point->meth;
808}
809#endif
810
811int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
812{
813 if (group->meth->point_set_to_infinity == 0) {
814 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
815 return 0;
816 }
817 if (group->meth != point->meth) {
818 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
819 return 0;
820 }
821 return group->meth->point_set_to_infinity(group, point);
822}
823
824#ifndef OPENSSL_NO_DEPRECATED_3_0
825int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
826 EC_POINT *point, const BIGNUM *x,
827 const BIGNUM *y, const BIGNUM *z,
828 BN_CTX *ctx)
829{
830 if (group->meth->field_type != NID_X9_62_prime_field) {
831 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
832 return 0;
833 }
834 if (!ec_point_is_compat(point, group)) {
835 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
836 return 0;
837 }
838 return ossl_ec_GFp_simple_set_Jprojective_coordinates_GFp(group, point,
839 x, y, z, ctx);
840}
841
842int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
843 const EC_POINT *point, BIGNUM *x,
844 BIGNUM *y, BIGNUM *z,
845 BN_CTX *ctx)
846{
847 if (group->meth->field_type != NID_X9_62_prime_field) {
848 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
849 return 0;
850 }
851 if (!ec_point_is_compat(point, group)) {
852 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
853 return 0;
854 }
855 return ossl_ec_GFp_simple_get_Jprojective_coordinates_GFp(group, point,
856 x, y, z, ctx);
857}
858#endif
859
860int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
861 const BIGNUM *x, const BIGNUM *y,
862 BN_CTX *ctx)
863{
864 if (group->meth->point_set_affine_coordinates == NULL) {
865 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
866 return 0;
867 }
868 if (!ec_point_is_compat(point, group)) {
869 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
870 return 0;
871 }
872 if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
873 return 0;
874
875 if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
876 ERR_raise(ERR_LIB_EC, EC_R_POINT_IS_NOT_ON_CURVE);
877 return 0;
878 }
879 return 1;
880}
881
882#ifndef OPENSSL_NO_DEPRECATED_3_0
883int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
884 EC_POINT *point, const BIGNUM *x,
885 const BIGNUM *y, BN_CTX *ctx)
886{
887 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
888}
889
890# ifndef OPENSSL_NO_EC2M
891int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
892 EC_POINT *point, const BIGNUM *x,
893 const BIGNUM *y, BN_CTX *ctx)
894{
895 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
896}
897# endif
898#endif
899
900int EC_POINT_get_affine_coordinates(const EC_GROUP *group,
901 const EC_POINT *point, BIGNUM *x, BIGNUM *y,
902 BN_CTX *ctx)
903{
904 if (group->meth->point_get_affine_coordinates == NULL) {
905 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
906 return 0;
907 }
908 if (!ec_point_is_compat(point, group)) {
909 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
910 return 0;
911 }
912 if (EC_POINT_is_at_infinity(group, point)) {
913 ERR_raise(ERR_LIB_EC, EC_R_POINT_AT_INFINITY);
914 return 0;
915 }
916 return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
917}
918
919#ifndef OPENSSL_NO_DEPRECATED_3_0
920int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
921 const EC_POINT *point, BIGNUM *x,
922 BIGNUM *y, BN_CTX *ctx)
923{
924 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
925}
926
927# ifndef OPENSSL_NO_EC2M
928int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
929 const EC_POINT *point, BIGNUM *x,
930 BIGNUM *y, BN_CTX *ctx)
931{
932 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
933}
934# endif
935#endif
936
937int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
938 const EC_POINT *b, BN_CTX *ctx)
939{
940 if (group->meth->add == 0) {
941 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
942 return 0;
943 }
944 if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)
945 || !ec_point_is_compat(b, group)) {
946 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
947 return 0;
948 }
949 return group->meth->add(group, r, a, b, ctx);
950}
951
952int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
953 BN_CTX *ctx)
954{
955 if (group->meth->dbl == 0) {
956 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
957 return 0;
958 }
959 if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) {
960 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
961 return 0;
962 }
963 return group->meth->dbl(group, r, a, ctx);
964}
965
966int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
967{
968 if (group->meth->invert == 0) {
969 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
970 return 0;
971 }
972 if (!ec_point_is_compat(a, group)) {
973 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
974 return 0;
975 }
976 return group->meth->invert(group, a, ctx);
977}
978
979int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
980{
981 if (group->meth->is_at_infinity == 0) {
982 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
983 return 0;
984 }
985 if (!ec_point_is_compat(point, group)) {
986 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
987 return 0;
988 }
989 return group->meth->is_at_infinity(group, point);
990}
991
992/*
993 * Check whether an EC_POINT is on the curve or not. Note that the return
994 * value for this function should NOT be treated as a boolean. Return values:
995 * 1: The point is on the curve
996 * 0: The point is not on the curve
997 * -1: An error occurred
998 */
999int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
1000 BN_CTX *ctx)
1001{
1002 if (group->meth->is_on_curve == 0) {
1003 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1004 return 0;
1005 }
1006 if (!ec_point_is_compat(point, group)) {
1007 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1008 return 0;
1009 }
1010 return group->meth->is_on_curve(group, point, ctx);
1011}
1012
1013int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
1014 BN_CTX *ctx)
1015{
1016 if (group->meth->point_cmp == 0) {
1017 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1018 return -1;
1019 }
1020 if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) {
1021 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1022 return -1;
1023 }
1024 return group->meth->point_cmp(group, a, b, ctx);
1025}
1026
1027#ifndef OPENSSL_NO_DEPRECATED_3_0
1028int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
1029{
1030 if (group->meth->make_affine == 0) {
1031 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1032 return 0;
1033 }
1034 if (!ec_point_is_compat(point, group)) {
1035 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1036 return 0;
1037 }
1038 return group->meth->make_affine(group, point, ctx);
1039}
1040
1041int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
1042 EC_POINT *points[], BN_CTX *ctx)
1043{
1044 size_t i;
1045
1046 if (group->meth->points_make_affine == 0) {
1047 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1048 return 0;
1049 }
1050 for (i = 0; i < num; i++) {
1051 if (!ec_point_is_compat(points[i], group)) {
1052 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1053 return 0;
1054 }
1055 }
1056 return group->meth->points_make_affine(group, num, points, ctx);
1057}
1058#endif
1059
1060/*
1061 * Functions for point multiplication. If group->meth->mul is 0, we use the
1062 * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
1063 * methods.
1064 */
1065
1066#ifndef OPENSSL_NO_DEPRECATED_3_0
1067int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
1068 size_t num, const EC_POINT *points[],
1069 const BIGNUM *scalars[], BN_CTX *ctx)
1070{
1071 int ret = 0;
1072 size_t i = 0;
1073#ifndef FIPS_MODULE
1074 BN_CTX *new_ctx = NULL;
1075#endif
1076
1077 if (!ec_point_is_compat(r, group)) {
1078 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1079 return 0;
1080 }
1081
1082 if (scalar == NULL && num == 0)
1083 return EC_POINT_set_to_infinity(group, r);
1084
1085 for (i = 0; i < num; i++) {
1086 if (!ec_point_is_compat(points[i], group)) {
1087 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1088 return 0;
1089 }
1090 }
1091
1092#ifndef FIPS_MODULE
1093 if (ctx == NULL)
1094 ctx = new_ctx = BN_CTX_secure_new();
1095#endif
1096 if (ctx == NULL) {
1097 ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR);
1098 return 0;
1099 }
1100
1101 if (group->meth->mul != NULL)
1102 ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx);
1103 else
1104 /* use default */
1105 ret = ossl_ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
1106
1107#ifndef FIPS_MODULE
1108 BN_CTX_free(new_ctx);
1109#endif
1110 return ret;
1111}
1112#endif
1113
1114int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
1115 const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
1116{
1117 int ret = 0;
1118 size_t num;
1119#ifndef FIPS_MODULE
1120 BN_CTX *new_ctx = NULL;
1121#endif
1122
1123 if (!ec_point_is_compat(r, group)
1124 || (point != NULL && !ec_point_is_compat(point, group))) {
1125 ERR_raise(ERR_LIB_EC, EC_R_INCOMPATIBLE_OBJECTS);
1126 return 0;
1127 }
1128
1129 if (g_scalar == NULL && p_scalar == NULL)
1130 return EC_POINT_set_to_infinity(group, r);
1131
1132#ifndef FIPS_MODULE
1133 if (ctx == NULL)
1134 ctx = new_ctx = BN_CTX_secure_new();
1135#endif
1136 if (ctx == NULL) {
1137 ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR);
1138 return 0;
1139 }
1140
1141 num = (point != NULL && p_scalar != NULL) ? 1 : 0;
1142 if (group->meth->mul != NULL)
1143 ret = group->meth->mul(group, r, g_scalar, num, &point, &p_scalar, ctx);
1144 else
1145 /* use default */
1146 ret = ossl_ec_wNAF_mul(group, r, g_scalar, num, &point, &p_scalar, ctx);
1147
1148#ifndef FIPS_MODULE
1149 BN_CTX_free(new_ctx);
1150#endif
1151 return ret;
1152}
1153
1154#ifndef OPENSSL_NO_DEPRECATED_3_0
1155int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
1156{
1157 if (group->meth->mul == 0)
1158 /* use default */
1159 return ossl_ec_wNAF_precompute_mult(group, ctx);
1160
1161 if (group->meth->precompute_mult != 0)
1162 return group->meth->precompute_mult(group, ctx);
1163 else
1164 return 1; /* nothing to do, so report success */
1165}
1166
1167int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
1168{
1169 if (group->meth->mul == 0)
1170 /* use default */
1171 return ossl_ec_wNAF_have_precompute_mult(group);
1172
1173 if (group->meth->have_precompute_mult != 0)
1174 return group->meth->have_precompute_mult(group);
1175 else
1176 return 0; /* cannot tell whether precomputation has
1177 * been performed */
1178}
1179#endif
1180
1181/*
1182 * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
1183 * returns one on success. On error it returns zero.
1184 */
1185static int ec_precompute_mont_data(EC_GROUP *group)
1186{
1187 BN_CTX *ctx = BN_CTX_new_ex(group->libctx);
1188 int ret = 0;
1189
1190 BN_MONT_CTX_free(group->mont_data);
1191 group->mont_data = NULL;
1192
1193 if (ctx == NULL)
1194 goto err;
1195
1196 group->mont_data = BN_MONT_CTX_new();
1197 if (group->mont_data == NULL)
1198 goto err;
1199
1200 if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
1201 BN_MONT_CTX_free(group->mont_data);
1202 group->mont_data = NULL;
1203 goto err;
1204 }
1205
1206 ret = 1;
1207
1208 err:
1209
1210 BN_CTX_free(ctx);
1211 return ret;
1212}
1213
1214#ifndef FIPS_MODULE
1215int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg)
1216{
1217 return CRYPTO_set_ex_data(&key->ex_data, idx, arg);
1218}
1219
1220void *EC_KEY_get_ex_data(const EC_KEY *key, int idx)
1221{
1222 return CRYPTO_get_ex_data(&key->ex_data, idx);
1223}
1224#endif
1225
1226int ossl_ec_group_simple_order_bits(const EC_GROUP *group)
1227{
1228 if (group->order == NULL)
1229 return 0;
1230 return BN_num_bits(group->order);
1231}
1232
1233static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r,
1234 const BIGNUM *x, BN_CTX *ctx)
1235{
1236 BIGNUM *e = NULL;
1237 int ret = 0;
1238#ifndef FIPS_MODULE
1239 BN_CTX *new_ctx = NULL;
1240#endif
1241
1242 if (group->mont_data == NULL)
1243 return 0;
1244
1245#ifndef FIPS_MODULE
1246 if (ctx == NULL)
1247 ctx = new_ctx = BN_CTX_secure_new();
1248#endif
1249 if (ctx == NULL)
1250 return 0;
1251
1252 BN_CTX_start(ctx);
1253 if ((e = BN_CTX_get(ctx)) == NULL)
1254 goto err;
1255
1256 /*-
1257 * We want inverse in constant time, therefore we utilize the fact
1258 * order must be prime and use Fermats Little Theorem instead.
1259 */
1260 if (!BN_set_word(e, 2))
1261 goto err;
1262 if (!BN_sub(e, group->order, e))
1263 goto err;
1264 /*-
1265 * Exponent e is public.
1266 * No need for scatter-gather or BN_FLG_CONSTTIME.
1267 */
1268 if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data))
1269 goto err;
1270
1271 ret = 1;
1272
1273 err:
1274 BN_CTX_end(ctx);
1275#ifndef FIPS_MODULE
1276 BN_CTX_free(new_ctx);
1277#endif
1278 return ret;
1279}
1280
1281/*-
1282 * Default behavior, if group->meth->field_inverse_mod_ord is NULL:
1283 * - When group->order is even, this function returns an error.
1284 * - When group->order is otherwise composite, the correctness
1285 * of the output is not guaranteed.
1286 * - When x is outside the range [1, group->order), the correctness
1287 * of the output is not guaranteed.
1288 * - Otherwise, this function returns the multiplicative inverse in the
1289 * range [1, group->order).
1290 *
1291 * EC_METHODs must implement their own field_inverse_mod_ord for
1292 * other functionality.
1293 */
1294int ossl_ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
1295 const BIGNUM *x, BN_CTX *ctx)
1296{
1297 if (group->meth->field_inverse_mod_ord != NULL)
1298 return group->meth->field_inverse_mod_ord(group, res, x, ctx);
1299 else
1300 return ec_field_inverse_mod_ord(group, res, x, ctx);
1301}
1302
1303/*-
1304 * Coordinate blinding for EC_POINT.
1305 *
1306 * The underlying EC_METHOD can optionally implement this function:
1307 * underlying implementations should return 0 on errors, or 1 on
1308 * success.
1309 *
1310 * This wrapper returns 1 in case the underlying EC_METHOD does not
1311 * support coordinate blinding.
1312 */
1313int ossl_ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p,
1314 BN_CTX *ctx)
1315{
1316 if (group->meth->blind_coordinates == NULL)
1317 return 1; /* ignore if not implemented */
1318
1319 return group->meth->blind_coordinates(group, p, ctx);
1320}
1321
1322int EC_GROUP_get_basis_type(const EC_GROUP *group)
1323{
1324 int i;
1325
1326 if (EC_GROUP_get_field_type(group) != NID_X9_62_characteristic_two_field)
1327 /* everything else is currently not supported */
1328 return 0;
1329
1330 /* Find the last non-zero element of group->poly[] */
1331 for (i = 0;
1332 i < (int)OSSL_NELEM(group->poly) && group->poly[i] != 0;
1333 i++)
1334 continue;
1335
1336 if (i == 4)
1337 return NID_X9_62_ppBasis;
1338 else if (i == 2)
1339 return NID_X9_62_tpBasis;
1340 else
1341 /* everything else is currently not supported */
1342 return 0;
1343}
1344
1345#ifndef OPENSSL_NO_EC2M
1346int EC_GROUP_get_trinomial_basis(const EC_GROUP *group, unsigned int *k)
1347{
1348 if (group == NULL)
1349 return 0;
1350
1351 if (EC_GROUP_get_field_type(group) != NID_X9_62_characteristic_two_field
1352 || !((group->poly[0] != 0) && (group->poly[1] != 0)
1353 && (group->poly[2] == 0))) {
1354 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1355 return 0;
1356 }
1357
1358 if (k)
1359 *k = group->poly[1];
1360
1361 return 1;
1362}
1363
1364int EC_GROUP_get_pentanomial_basis(const EC_GROUP *group, unsigned int *k1,
1365 unsigned int *k2, unsigned int *k3)
1366{
1367 if (group == NULL)
1368 return 0;
1369
1370 if (EC_GROUP_get_field_type(group) != NID_X9_62_characteristic_two_field
1371 || !((group->poly[0] != 0) && (group->poly[1] != 0)
1372 && (group->poly[2] != 0) && (group->poly[3] != 0)
1373 && (group->poly[4] == 0))) {
1374 ERR_raise(ERR_LIB_EC, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
1375 return 0;
1376 }
1377
1378 if (k1)
1379 *k1 = group->poly[3];
1380 if (k2)
1381 *k2 = group->poly[2];
1382 if (k3)
1383 *k3 = group->poly[1];
1384
1385 return 1;
1386}
1387#endif
1388
1389#ifndef FIPS_MODULE
1390/*
1391 * Check if the explicit parameters group matches any built-in curves.
1392 *
1393 * We create a copy of the group just built, so that we can remove optional
1394 * fields for the lookup: we do this to avoid the possibility that one of
1395 * the optional parameters is used to force the library into using a less
1396 * performant and less secure EC_METHOD instead of the specialized one.
1397 * In any case, `seed` is not really used in any computation, while a
1398 * cofactor different from the one in the built-in table is just
1399 * mathematically wrong anyway and should not be used.
1400 */
1401static EC_GROUP *ec_group_explicit_to_named(const EC_GROUP *group,
1402 OSSL_LIB_CTX *libctx,
1403 const char *propq,
1404 BN_CTX *ctx)
1405{
1406 EC_GROUP *ret_group = NULL, *dup = NULL;
1407 int curve_name_nid;
1408
1409 const EC_POINT *point = EC_GROUP_get0_generator(group);
1410 const BIGNUM *order = EC_GROUP_get0_order(group);
1411 int no_seed = (EC_GROUP_get0_seed(group) == NULL);
1412
1413 if ((dup = EC_GROUP_dup(group)) == NULL
1414 || EC_GROUP_set_seed(dup, NULL, 0) != 1
1415 || !EC_GROUP_set_generator(dup, point, order, NULL))
1416 goto err;
1417 if ((curve_name_nid = ossl_ec_curve_nid_from_params(dup, ctx)) != NID_undef) {
1418 /*
1419 * The input explicit parameters successfully matched one of the
1420 * built-in curves: often for built-in curves we have specialized
1421 * methods with better performance and hardening.
1422 *
1423 * In this case we replace the `EC_GROUP` created through explicit
1424 * parameters with one created from a named group.
1425 */
1426
1427# ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
1428 /*
1429 * NID_wap_wsg_idm_ecid_wtls12 and NID_secp224r1 are both aliases for
1430 * the same curve, we prefer the SECP nid when matching explicit
1431 * parameters as that is associated with a specialized EC_METHOD.
1432 */
1433 if (curve_name_nid == NID_wap_wsg_idm_ecid_wtls12)
1434 curve_name_nid = NID_secp224r1;
1435# endif /* !def(OPENSSL_NO_EC_NISTP_64_GCC_128) */
1436
1437 ret_group = EC_GROUP_new_by_curve_name_ex(libctx, propq, curve_name_nid);
1438 if (ret_group == NULL)
1439 goto err;
1440
1441 /*
1442 * Set the flag so that EC_GROUPs created from explicit parameters are
1443 * serialized using explicit parameters by default.
1444 */
1445 EC_GROUP_set_asn1_flag(ret_group, OPENSSL_EC_EXPLICIT_CURVE);
1446
1447 /*
1448 * If the input params do not contain the optional seed field we make
1449 * sure it is not added to the returned group.
1450 *
1451 * The seed field is not really used inside libcrypto anyway, and
1452 * adding it to parsed explicit parameter keys would alter their DER
1453 * encoding output (because of the extra field) which could impact
1454 * applications fingerprinting keys by their DER encoding.
1455 */
1456 if (no_seed) {
1457 if (EC_GROUP_set_seed(ret_group, NULL, 0) != 1)
1458 goto err;
1459 }
1460 } else {
1461 ret_group = (EC_GROUP *)group;
1462 }
1463 EC_GROUP_free(dup);
1464 return ret_group;
1465err:
1466 EC_GROUP_free(dup);
1467 EC_GROUP_free(ret_group);
1468 return NULL;
1469}
1470#endif /* FIPS_MODULE */
1471
1472static EC_GROUP *group_new_from_name(const OSSL_PARAM *p,
1473 OSSL_LIB_CTX *libctx, const char *propq)
1474{
1475 int ok = 0, nid;
1476 const char *curve_name = NULL;
1477
1478 switch (p->data_type) {
1479 case OSSL_PARAM_UTF8_STRING:
1480 /* The OSSL_PARAM functions have no support for this */
1481 curve_name = p->data;
1482 ok = (curve_name != NULL);
1483 break;
1484 case OSSL_PARAM_UTF8_PTR:
1485 ok = OSSL_PARAM_get_utf8_ptr(p, &curve_name);
1486 break;
1487 }
1488
1489 if (ok) {
1490 nid = ossl_ec_curve_name2nid(curve_name);
1491 if (nid == NID_undef) {
1492 ERR_raise(ERR_LIB_EC, EC_R_INVALID_CURVE);
1493 return NULL;
1494 } else {
1495 return EC_GROUP_new_by_curve_name_ex(libctx, propq, nid);
1496 }
1497 }
1498 return NULL;
1499}
1500
1501/* These parameters can be set directly into an EC_GROUP */
1502int ossl_ec_group_set_params(EC_GROUP *group, const OSSL_PARAM params[])
1503{
1504 int encoding_flag = -1, format = -1;
1505 const OSSL_PARAM *p;
1506
1507 p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_POINT_CONVERSION_FORMAT);
1508 if (p != NULL) {
1509 if (!ossl_ec_pt_format_param2id(p, &format)) {
1510 ECerr(0, EC_R_INVALID_FORM);
1511 return 0;
1512 }
1513 EC_GROUP_set_point_conversion_form(group, format);
1514 }
1515
1516 p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ENCODING);
1517 if (p != NULL) {
1518 if (!ossl_ec_encoding_param2id(p, &encoding_flag)) {
1519 ECerr(0, EC_R_INVALID_FORM);
1520 return 0;
1521 }
1522 EC_GROUP_set_asn1_flag(group, encoding_flag);
1523 }
1524 /* Optional seed */
1525 p = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_SEED);
1526 if (p != NULL) {
1527 /* The seed is allowed to be NULL */
1528 if (p->data_type != OSSL_PARAM_OCTET_STRING
1529 || !EC_GROUP_set_seed(group, p->data, p->data_size)) {
1530 ECerr(0, EC_R_INVALID_SEED);
1531 return 0;
1532 }
1533 }
1534 return 1;
1535}
1536
1537EC_GROUP *EC_GROUP_new_from_params(const OSSL_PARAM params[],
1538 OSSL_LIB_CTX *libctx, const char *propq)
1539{
1540 const OSSL_PARAM *ptmp;
1541 EC_GROUP *group = NULL;
1542
1543#ifndef FIPS_MODULE
1544 const OSSL_PARAM *pa, *pb;
1545 int ok = 0;
1546 EC_GROUP *named_group = NULL;
1547 BIGNUM *p = NULL, *a = NULL, *b = NULL, *order = NULL, *cofactor = NULL;
1548 EC_POINT *point = NULL;
1549 int field_bits = 0;
1550 int is_prime_field = 1;
1551 BN_CTX *bnctx = NULL;
1552 const unsigned char *buf = NULL;
1553 int encoding_flag = -1;
1554#endif
1555
1556 /* This is the simple named group case */
1557 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_GROUP_NAME);
1558 if (ptmp != NULL) {
1559 int decoded = 0;
1560
1561 if ((group = group_new_from_name(ptmp, libctx, propq)) == NULL)
1562 return NULL;
1563 if (!ossl_ec_group_set_params(group, params)) {
1564 EC_GROUP_free(group);
1565 return NULL;
1566 }
1567
1568 ptmp = OSSL_PARAM_locate_const(params,
1569 OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS);
1570 if (ptmp != NULL && !OSSL_PARAM_get_int(ptmp, &decoded)) {
1571 ERR_raise(ERR_LIB_EC, EC_R_WRONG_CURVE_PARAMETERS);
1572 EC_GROUP_free(group);
1573 return NULL;
1574 }
1575 group->decoded_from_explicit_params = decoded > 0;
1576 return group;
1577 }
1578#ifdef FIPS_MODULE
1579 ERR_raise(ERR_LIB_EC, EC_R_EXPLICIT_PARAMS_NOT_SUPPORTED);
1580 return NULL;
1581#else
1582 /* If it gets here then we are trying explicit parameters */
1583 bnctx = BN_CTX_new_ex(libctx);
1584 if (bnctx == NULL) {
1585 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
1586 return 0;
1587 }
1588 BN_CTX_start(bnctx);
1589
1590 p = BN_CTX_get(bnctx);
1591 a = BN_CTX_get(bnctx);
1592 b = BN_CTX_get(bnctx);
1593 order = BN_CTX_get(bnctx);
1594 if (order == NULL) {
1595 ERR_raise(ERR_LIB_EC, ERR_R_MALLOC_FAILURE);
1596 goto err;
1597 }
1598
1599 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_FIELD_TYPE);
1600 if (ptmp == NULL || ptmp->data_type != OSSL_PARAM_UTF8_STRING) {
1601 ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD);
1602 goto err;
1603 }
1604 if (OPENSSL_strcasecmp(ptmp->data, SN_X9_62_prime_field) == 0) {
1605 is_prime_field = 1;
1606 } else if (OPENSSL_strcasecmp(ptmp->data,
1607 SN_X9_62_characteristic_two_field) == 0) {
1608 is_prime_field = 0;
1609 } else {
1610 /* Invalid field */
1611 ERR_raise(ERR_LIB_EC, EC_R_UNSUPPORTED_FIELD);
1612 goto err;
1613 }
1614
1615 pa = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_A);
1616 if (!OSSL_PARAM_get_BN(pa, &a)) {
1617 ERR_raise(ERR_LIB_EC, EC_R_INVALID_A);
1618 goto err;
1619 }
1620 pb = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_B);
1621 if (!OSSL_PARAM_get_BN(pb, &b)) {
1622 ERR_raise(ERR_LIB_EC, EC_R_INVALID_B);
1623 goto err;
1624 }
1625
1626 /* extract the prime number or irreducible polynomial */
1627 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_P);
1628 if (!OSSL_PARAM_get_BN(ptmp, &p)) {
1629 ERR_raise(ERR_LIB_EC, EC_R_INVALID_P);
1630 goto err;
1631 }
1632
1633 if (is_prime_field) {
1634 if (BN_is_negative(p) || BN_is_zero(p)) {
1635 ERR_raise(ERR_LIB_EC, EC_R_INVALID_P);
1636 goto err;
1637 }
1638 field_bits = BN_num_bits(p);
1639 if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) {
1640 ERR_raise(ERR_LIB_EC, EC_R_FIELD_TOO_LARGE);
1641 goto err;
1642 }
1643
1644 /* create the EC_GROUP structure */
1645 group = EC_GROUP_new_curve_GFp(p, a, b, bnctx);
1646 } else {
1647# ifdef OPENSSL_NO_EC2M
1648 ERR_raise(ERR_LIB_EC, EC_R_GF2M_NOT_SUPPORTED);
1649 goto err;
1650# else
1651 /* create the EC_GROUP structure */
1652 group = EC_GROUP_new_curve_GF2m(p, a, b, NULL);
1653 if (group != NULL) {
1654 field_bits = EC_GROUP_get_degree(group);
1655 if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS) {
1656 ERR_raise(ERR_LIB_EC, EC_R_FIELD_TOO_LARGE);
1657 goto err;
1658 }
1659 }
1660# endif /* OPENSSL_NO_EC2M */
1661 }
1662
1663 if (group == NULL) {
1664 ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
1665 goto err;
1666 }
1667
1668 /* Optional seed */
1669 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_SEED);
1670 if (ptmp != NULL) {
1671 if (ptmp->data_type != OSSL_PARAM_OCTET_STRING) {
1672 ERR_raise(ERR_LIB_EC, EC_R_INVALID_SEED);
1673 goto err;
1674 }
1675 if (!EC_GROUP_set_seed(group, ptmp->data, ptmp->data_size))
1676 goto err;
1677 }
1678
1679 /* generator base point */
1680 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_GENERATOR);
1681 if (ptmp == NULL
1682 || ptmp->data_type != OSSL_PARAM_OCTET_STRING) {
1683 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR);
1684 goto err;
1685 }
1686 buf = (const unsigned char *)(ptmp->data);
1687 if ((point = EC_POINT_new(group)) == NULL)
1688 goto err;
1689 EC_GROUP_set_point_conversion_form(group,
1690 (point_conversion_form_t)buf[0] & ~0x01);
1691 if (!EC_POINT_oct2point(group, point, buf, ptmp->data_size, bnctx)) {
1692 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR);
1693 goto err;
1694 }
1695
1696 /* order */
1697 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ORDER);
1698 if (!OSSL_PARAM_get_BN(ptmp, &order)
1699 || (BN_is_negative(order) || BN_is_zero(order))
1700 || (BN_num_bits(order) > (int)field_bits + 1)) { /* Hasse bound */
1701 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GROUP_ORDER);
1702 goto err;
1703 }
1704
1705 /* Optional cofactor */
1706 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_COFACTOR);
1707 if (ptmp != NULL) {
1708 cofactor = BN_CTX_get(bnctx);
1709 if (cofactor == NULL || !OSSL_PARAM_get_BN(ptmp, &cofactor)) {
1710 ERR_raise(ERR_LIB_EC, EC_R_INVALID_COFACTOR);
1711 goto err;
1712 }
1713 }
1714
1715 /* set the generator, order and cofactor (if present) */
1716 if (!EC_GROUP_set_generator(group, point, order, cofactor)) {
1717 ERR_raise(ERR_LIB_EC, EC_R_INVALID_GENERATOR);
1718 goto err;
1719 }
1720
1721 named_group = ec_group_explicit_to_named(group, libctx, propq, bnctx);
1722 if (named_group == NULL) {
1723 ERR_raise(ERR_LIB_EC, EC_R_INVALID_NAMED_GROUP_CONVERSION);
1724 goto err;
1725 }
1726 if (named_group == group) {
1727 /*
1728 * If we did not find a named group then the encoding should be explicit
1729 * if it was specified
1730 */
1731 ptmp = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_EC_ENCODING);
1732 if (ptmp != NULL
1733 && !ossl_ec_encoding_param2id(ptmp, &encoding_flag)) {
1734 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
1735 goto err;
1736 }
1737 if (encoding_flag == OPENSSL_EC_NAMED_CURVE) {
1738 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
1739 goto err;
1740 }
1741 EC_GROUP_set_asn1_flag(group, OPENSSL_EC_EXPLICIT_CURVE);
1742 } else {
1743 EC_GROUP_free(group);
1744 group = named_group;
1745 }
1746 /* We've imported the group from explicit parameters, set it so. */
1747 group->decoded_from_explicit_params = 1;
1748 ok = 1;
1749 err:
1750 if (!ok) {
1751 EC_GROUP_free(group);
1752 group = NULL;
1753 }
1754 EC_POINT_free(point);
1755 BN_CTX_end(bnctx);
1756 BN_CTX_free(bnctx);
1757
1758 return group;
1759#endif /* FIPS_MODULE */
1760}
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