2 * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
5 * Licensed under the OpenSSL license (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
13 #include <openssl/err.h>
14 #include <openssl/opensslv.h>
18 /* functions for EC_GROUP objects */
20 EC_GROUP *EC_GROUP_new(const EC_METHOD *meth)
25 ECerr(EC_F_EC_GROUP_NEW, EC_R_SLOT_FULL);
28 if (meth->group_init == 0) {
29 ECerr(EC_F_EC_GROUP_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
33 ret = OPENSSL_zalloc(sizeof(*ret));
35 ECerr(EC_F_EC_GROUP_NEW, ERR_R_MALLOC_FAILURE);
40 if ((ret->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
41 ret->order = BN_new();
42 if (ret->order == NULL)
44 ret->cofactor = BN_new();
45 if (ret->cofactor == NULL)
48 ret->asn1_flag = OPENSSL_EC_NAMED_CURVE;
49 ret->asn1_form = POINT_CONVERSION_UNCOMPRESSED;
50 if (!meth->group_init(ret))
56 BN_free(ret->cofactor);
61 void EC_pre_comp_free(EC_GROUP *group)
63 switch (group->pre_comp_type) {
67 #ifdef ECP_NISTZ256_ASM
68 EC_nistz256_pre_comp_free(group->pre_comp.nistz256);
71 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
73 EC_nistp224_pre_comp_free(group->pre_comp.nistp224);
76 EC_nistp256_pre_comp_free(group->pre_comp.nistp256);
79 EC_nistp521_pre_comp_free(group->pre_comp.nistp521);
88 EC_ec_pre_comp_free(group->pre_comp.ec);
91 group->pre_comp.ec = NULL;
94 void EC_GROUP_free(EC_GROUP *group)
99 if (group->meth->group_finish != 0)
100 group->meth->group_finish(group);
102 EC_pre_comp_free(group);
103 BN_MONT_CTX_free(group->mont_data);
104 EC_POINT_free(group->generator);
105 BN_free(group->order);
106 BN_free(group->cofactor);
107 OPENSSL_free(group->seed);
111 void EC_GROUP_clear_free(EC_GROUP *group)
116 if (group->meth->group_clear_finish != 0)
117 group->meth->group_clear_finish(group);
118 else if (group->meth->group_finish != 0)
119 group->meth->group_finish(group);
121 EC_pre_comp_free(group);
122 BN_MONT_CTX_free(group->mont_data);
123 EC_POINT_clear_free(group->generator);
124 BN_clear_free(group->order);
125 BN_clear_free(group->cofactor);
126 OPENSSL_clear_free(group->seed, group->seed_len);
127 OPENSSL_clear_free(group, sizeof(*group));
130 int EC_GROUP_copy(EC_GROUP *dest, const EC_GROUP *src)
132 if (dest->meth->group_copy == 0) {
133 ECerr(EC_F_EC_GROUP_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
136 if (dest->meth != src->meth) {
137 ECerr(EC_F_EC_GROUP_COPY, EC_R_INCOMPATIBLE_OBJECTS);
143 dest->curve_name = src->curve_name;
145 /* Copy precomputed */
146 dest->pre_comp_type = src->pre_comp_type;
147 switch (src->pre_comp_type) {
149 dest->pre_comp.ec = NULL;
152 #ifdef ECP_NISTZ256_ASM
153 dest->pre_comp.nistz256 = EC_nistz256_pre_comp_dup(src->pre_comp.nistz256);
156 #ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
158 dest->pre_comp.nistp224 = EC_nistp224_pre_comp_dup(src->pre_comp.nistp224);
161 dest->pre_comp.nistp256 = EC_nistp256_pre_comp_dup(src->pre_comp.nistp256);
164 dest->pre_comp.nistp521 = EC_nistp521_pre_comp_dup(src->pre_comp.nistp521);
173 dest->pre_comp.ec = EC_ec_pre_comp_dup(src->pre_comp.ec);
177 if (src->mont_data != NULL) {
178 if (dest->mont_data == NULL) {
179 dest->mont_data = BN_MONT_CTX_new();
180 if (dest->mont_data == NULL)
183 if (!BN_MONT_CTX_copy(dest->mont_data, src->mont_data))
186 /* src->generator == NULL */
187 BN_MONT_CTX_free(dest->mont_data);
188 dest->mont_data = NULL;
191 if (src->generator != NULL) {
192 if (dest->generator == NULL) {
193 dest->generator = EC_POINT_new(dest);
194 if (dest->generator == NULL)
197 if (!EC_POINT_copy(dest->generator, src->generator))
200 /* src->generator == NULL */
201 EC_POINT_clear_free(dest->generator);
202 dest->generator = NULL;
205 if ((src->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) {
206 if (!BN_copy(dest->order, src->order))
208 if (!BN_copy(dest->cofactor, src->cofactor))
212 dest->asn1_flag = src->asn1_flag;
213 dest->asn1_form = src->asn1_form;
216 OPENSSL_free(dest->seed);
217 if ((dest->seed = OPENSSL_malloc(src->seed_len)) == NULL) {
218 ECerr(EC_F_EC_GROUP_COPY, ERR_R_MALLOC_FAILURE);
221 if (!memcpy(dest->seed, src->seed, src->seed_len))
223 dest->seed_len = src->seed_len;
225 OPENSSL_free(dest->seed);
230 return dest->meth->group_copy(dest, src);
233 EC_GROUP *EC_GROUP_dup(const EC_GROUP *a)
241 if ((t = EC_GROUP_new(a->meth)) == NULL)
243 if (!EC_GROUP_copy(t, a))
256 const EC_METHOD *EC_GROUP_method_of(const EC_GROUP *group)
261 int EC_METHOD_get_field_type(const EC_METHOD *meth)
263 return meth->field_type;
266 static int ec_precompute_mont_data(EC_GROUP *);
268 int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator,
269 const BIGNUM *order, const BIGNUM *cofactor)
271 if (generator == NULL) {
272 ECerr(EC_F_EC_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
276 if (group->generator == NULL) {
277 group->generator = EC_POINT_new(group);
278 if (group->generator == NULL)
281 if (!EC_POINT_copy(group->generator, generator))
285 if (!BN_copy(group->order, order))
288 BN_zero(group->order);
290 if (cofactor != NULL) {
291 if (!BN_copy(group->cofactor, cofactor))
294 BN_zero(group->cofactor);
297 * Some groups have an order with
298 * factors of two, which makes the Montgomery setup fail.
299 * |group->mont_data| will be NULL in this case.
301 if (BN_is_odd(group->order)) {
302 return ec_precompute_mont_data(group);
305 BN_MONT_CTX_free(group->mont_data);
306 group->mont_data = NULL;
310 const EC_POINT *EC_GROUP_get0_generator(const EC_GROUP *group)
312 return group->generator;
315 BN_MONT_CTX *EC_GROUP_get_mont_data(const EC_GROUP *group)
317 return group->mont_data;
320 int EC_GROUP_get_order(const EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
322 if (group->order == NULL)
324 if (!BN_copy(order, group->order))
327 return !BN_is_zero(order);
330 const BIGNUM *EC_GROUP_get0_order(const EC_GROUP *group)
335 int EC_GROUP_order_bits(const EC_GROUP *group)
337 return group->meth->group_order_bits(group);
340 int EC_GROUP_get_cofactor(const EC_GROUP *group, BIGNUM *cofactor,
344 if (group->cofactor == NULL)
346 if (!BN_copy(cofactor, group->cofactor))
349 return !BN_is_zero(group->cofactor);
352 const BIGNUM *EC_GROUP_get0_cofactor(const EC_GROUP *group)
354 return group->cofactor;
357 void EC_GROUP_set_curve_name(EC_GROUP *group, int nid)
359 group->curve_name = nid;
362 int EC_GROUP_get_curve_name(const EC_GROUP *group)
364 return group->curve_name;
367 void EC_GROUP_set_asn1_flag(EC_GROUP *group, int flag)
369 group->asn1_flag = flag;
372 int EC_GROUP_get_asn1_flag(const EC_GROUP *group)
374 return group->asn1_flag;
377 void EC_GROUP_set_point_conversion_form(EC_GROUP *group,
378 point_conversion_form_t form)
380 group->asn1_form = form;
383 point_conversion_form_t EC_GROUP_get_point_conversion_form(const EC_GROUP
386 return group->asn1_form;
389 size_t EC_GROUP_set_seed(EC_GROUP *group, const unsigned char *p, size_t len)
391 OPENSSL_free(group->seed);
398 if ((group->seed = OPENSSL_malloc(len)) == NULL) {
399 ECerr(EC_F_EC_GROUP_SET_SEED, ERR_R_MALLOC_FAILURE);
402 memcpy(group->seed, p, len);
403 group->seed_len = len;
408 unsigned char *EC_GROUP_get0_seed(const EC_GROUP *group)
413 size_t EC_GROUP_get_seed_len(const EC_GROUP *group)
415 return group->seed_len;
418 int EC_GROUP_set_curve(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
419 const BIGNUM *b, BN_CTX *ctx)
421 if (group->meth->group_set_curve == 0) {
422 ECerr(EC_F_EC_GROUP_SET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
425 return group->meth->group_set_curve(group, p, a, b, ctx);
428 int EC_GROUP_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b,
431 if (group->meth->group_get_curve == NULL) {
432 ECerr(EC_F_EC_GROUP_GET_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
435 return group->meth->group_get_curve(group, p, a, b, ctx);
438 #if OPENSSL_API_COMPAT < 0x10200000L
439 int EC_GROUP_set_curve_GFp(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
440 const BIGNUM *b, BN_CTX *ctx)
442 return EC_GROUP_set_curve(group, p, a, b, ctx);
445 int EC_GROUP_get_curve_GFp(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
446 BIGNUM *b, BN_CTX *ctx)
448 return EC_GROUP_get_curve(group, p, a, b, ctx);
451 # ifndef OPENSSL_NO_EC2M
452 int EC_GROUP_set_curve_GF2m(EC_GROUP *group, const BIGNUM *p, const BIGNUM *a,
453 const BIGNUM *b, BN_CTX *ctx)
455 return EC_GROUP_set_curve(group, p, a, b, ctx);
458 int EC_GROUP_get_curve_GF2m(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
459 BIGNUM *b, BN_CTX *ctx)
461 return EC_GROUP_get_curve(group, p, a, b, ctx);
466 int EC_GROUP_get_degree(const EC_GROUP *group)
468 if (group->meth->group_get_degree == 0) {
469 ECerr(EC_F_EC_GROUP_GET_DEGREE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
472 return group->meth->group_get_degree(group);
475 int EC_GROUP_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
477 if (group->meth->group_check_discriminant == 0) {
478 ECerr(EC_F_EC_GROUP_CHECK_DISCRIMINANT,
479 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
482 return group->meth->group_check_discriminant(group, ctx);
485 int EC_GROUP_cmp(const EC_GROUP *a, const EC_GROUP *b, BN_CTX *ctx)
488 BIGNUM *a1, *a2, *a3, *b1, *b2, *b3;
489 BN_CTX *ctx_new = NULL;
491 /* compare the field types */
492 if (EC_METHOD_get_field_type(EC_GROUP_method_of(a)) !=
493 EC_METHOD_get_field_type(EC_GROUP_method_of(b)))
495 /* compare the curve name (if present in both) */
496 if (EC_GROUP_get_curve_name(a) && EC_GROUP_get_curve_name(b) &&
497 EC_GROUP_get_curve_name(a) != EC_GROUP_get_curve_name(b))
499 if (a->meth->flags & EC_FLAGS_CUSTOM_CURVE)
503 ctx_new = ctx = BN_CTX_new();
508 a1 = BN_CTX_get(ctx);
509 a2 = BN_CTX_get(ctx);
510 a3 = BN_CTX_get(ctx);
511 b1 = BN_CTX_get(ctx);
512 b2 = BN_CTX_get(ctx);
513 b3 = BN_CTX_get(ctx);
516 BN_CTX_free(ctx_new);
521 * XXX This approach assumes that the external representation of curves
522 * over the same field type is the same.
524 if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
525 !b->meth->group_get_curve(b, b1, b2, b3, ctx))
528 if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
531 /* XXX EC_POINT_cmp() assumes that the methods are equal */
532 if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
533 EC_GROUP_get0_generator(b), ctx))
537 const BIGNUM *ao, *bo, *ac, *bc;
538 /* compare the order and cofactor */
539 ao = EC_GROUP_get0_order(a);
540 bo = EC_GROUP_get0_order(b);
541 ac = EC_GROUP_get0_cofactor(a);
542 bc = EC_GROUP_get0_cofactor(b);
543 if (ao == NULL || bo == NULL) {
545 BN_CTX_free(ctx_new);
548 if (BN_cmp(ao, bo) || BN_cmp(ac, bc))
553 BN_CTX_free(ctx_new);
558 /* functions for EC_POINT objects */
560 EC_POINT *EC_POINT_new(const EC_GROUP *group)
565 ECerr(EC_F_EC_POINT_NEW, ERR_R_PASSED_NULL_PARAMETER);
568 if (group->meth->point_init == NULL) {
569 ECerr(EC_F_EC_POINT_NEW, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
573 ret = OPENSSL_zalloc(sizeof(*ret));
575 ECerr(EC_F_EC_POINT_NEW, ERR_R_MALLOC_FAILURE);
579 ret->meth = group->meth;
580 ret->curve_name = group->curve_name;
582 if (!ret->meth->point_init(ret)) {
590 void EC_POINT_free(EC_POINT *point)
595 if (point->meth->point_finish != 0)
596 point->meth->point_finish(point);
600 void EC_POINT_clear_free(EC_POINT *point)
605 if (point->meth->point_clear_finish != 0)
606 point->meth->point_clear_finish(point);
607 else if (point->meth->point_finish != 0)
608 point->meth->point_finish(point);
609 OPENSSL_clear_free(point, sizeof(*point));
612 int EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
614 if (dest->meth->point_copy == 0) {
615 ECerr(EC_F_EC_POINT_COPY, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
618 if (dest->meth != src->meth
619 || (dest->curve_name != src->curve_name
620 && dest->curve_name != 0
621 && src->curve_name != 0)) {
622 ECerr(EC_F_EC_POINT_COPY, EC_R_INCOMPATIBLE_OBJECTS);
627 return dest->meth->point_copy(dest, src);
630 EC_POINT *EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
638 t = EC_POINT_new(group);
641 r = EC_POINT_copy(t, a);
649 const EC_METHOD *EC_POINT_method_of(const EC_POINT *point)
654 int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
656 if (group->meth->point_set_to_infinity == 0) {
657 ECerr(EC_F_EC_POINT_SET_TO_INFINITY,
658 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
661 if (group->meth != point->meth) {
662 ECerr(EC_F_EC_POINT_SET_TO_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
665 return group->meth->point_set_to_infinity(group, point);
668 int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
669 EC_POINT *point, const BIGNUM *x,
670 const BIGNUM *y, const BIGNUM *z,
673 if (group->meth->point_set_Jprojective_coordinates_GFp == 0) {
674 ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
675 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
678 if (!ec_point_is_compat(point, group)) {
679 ECerr(EC_F_EC_POINT_SET_JPROJECTIVE_COORDINATES_GFP,
680 EC_R_INCOMPATIBLE_OBJECTS);
683 return group->meth->point_set_Jprojective_coordinates_GFp(group, point, x,
687 int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
688 const EC_POINT *point, BIGNUM *x,
689 BIGNUM *y, BIGNUM *z,
692 if (group->meth->point_get_Jprojective_coordinates_GFp == 0) {
693 ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
694 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
697 if (!ec_point_is_compat(point, group)) {
698 ECerr(EC_F_EC_POINT_GET_JPROJECTIVE_COORDINATES_GFP,
699 EC_R_INCOMPATIBLE_OBJECTS);
702 return group->meth->point_get_Jprojective_coordinates_GFp(group, point, x,
706 int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
707 const BIGNUM *x, const BIGNUM *y,
710 if (group->meth->point_set_affine_coordinates == NULL) {
711 ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES,
712 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
715 if (!ec_point_is_compat(point, group)) {
716 ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
719 if (!group->meth->point_set_affine_coordinates(group, point, x, y, ctx))
722 if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
723 ECerr(EC_F_EC_POINT_SET_AFFINE_COORDINATES, EC_R_POINT_IS_NOT_ON_CURVE);
729 #if OPENSSL_API_COMPAT < 0x10200000L
730 int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
731 EC_POINT *point, const BIGNUM *x,
732 const BIGNUM *y, BN_CTX *ctx)
734 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
737 # ifndef OPENSSL_NO_EC2M
738 int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group,
739 EC_POINT *point, const BIGNUM *x,
740 const BIGNUM *y, BN_CTX *ctx)
742 return EC_POINT_set_affine_coordinates(group, point, x, y, ctx);
747 int EC_POINT_get_affine_coordinates(const EC_GROUP *group,
748 const EC_POINT *point, BIGNUM *x, BIGNUM *y,
751 if (group->meth->point_get_affine_coordinates == NULL) {
752 ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES,
753 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
756 if (!ec_point_is_compat(point, group)) {
757 ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_INCOMPATIBLE_OBJECTS);
760 if (EC_POINT_is_at_infinity(group, point)) {
761 ECerr(EC_F_EC_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
764 return group->meth->point_get_affine_coordinates(group, point, x, y, ctx);
767 #if OPENSSL_API_COMPAT < 0x10200000L
768 int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
769 const EC_POINT *point, BIGNUM *x,
770 BIGNUM *y, BN_CTX *ctx)
772 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
775 # ifndef OPENSSL_NO_EC2M
776 int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
777 const EC_POINT *point, BIGNUM *x,
778 BIGNUM *y, BN_CTX *ctx)
780 return EC_POINT_get_affine_coordinates(group, point, x, y, ctx);
785 int EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
786 const EC_POINT *b, BN_CTX *ctx)
788 if (group->meth->add == 0) {
789 ECerr(EC_F_EC_POINT_ADD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
792 if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)
793 || !ec_point_is_compat(b, group)) {
794 ECerr(EC_F_EC_POINT_ADD, EC_R_INCOMPATIBLE_OBJECTS);
797 return group->meth->add(group, r, a, b, ctx);
800 int EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
803 if (group->meth->dbl == 0) {
804 ECerr(EC_F_EC_POINT_DBL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
807 if (!ec_point_is_compat(r, group) || !ec_point_is_compat(a, group)) {
808 ECerr(EC_F_EC_POINT_DBL, EC_R_INCOMPATIBLE_OBJECTS);
811 return group->meth->dbl(group, r, a, ctx);
814 int EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx)
816 if (group->meth->invert == 0) {
817 ECerr(EC_F_EC_POINT_INVERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
820 if (!ec_point_is_compat(a, group)) {
821 ECerr(EC_F_EC_POINT_INVERT, EC_R_INCOMPATIBLE_OBJECTS);
824 return group->meth->invert(group, a, ctx);
827 int EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
829 if (group->meth->is_at_infinity == 0) {
830 ECerr(EC_F_EC_POINT_IS_AT_INFINITY,
831 ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
834 if (!ec_point_is_compat(point, group)) {
835 ECerr(EC_F_EC_POINT_IS_AT_INFINITY, EC_R_INCOMPATIBLE_OBJECTS);
838 return group->meth->is_at_infinity(group, point);
842 * Check whether an EC_POINT is on the curve or not. Note that the return
843 * value for this function should NOT be treated as a boolean. Return values:
844 * 1: The point is on the curve
845 * 0: The point is not on the curve
846 * -1: An error occurred
848 int EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
851 if (group->meth->is_on_curve == 0) {
852 ECerr(EC_F_EC_POINT_IS_ON_CURVE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
855 if (!ec_point_is_compat(point, group)) {
856 ECerr(EC_F_EC_POINT_IS_ON_CURVE, EC_R_INCOMPATIBLE_OBJECTS);
859 return group->meth->is_on_curve(group, point, ctx);
862 int EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
865 if (group->meth->point_cmp == 0) {
866 ECerr(EC_F_EC_POINT_CMP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
869 if (!ec_point_is_compat(a, group) || !ec_point_is_compat(b, group)) {
870 ECerr(EC_F_EC_POINT_CMP, EC_R_INCOMPATIBLE_OBJECTS);
873 return group->meth->point_cmp(group, a, b, ctx);
876 int EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
878 if (group->meth->make_affine == 0) {
879 ECerr(EC_F_EC_POINT_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
882 if (!ec_point_is_compat(point, group)) {
883 ECerr(EC_F_EC_POINT_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
886 return group->meth->make_affine(group, point, ctx);
889 int EC_POINTs_make_affine(const EC_GROUP *group, size_t num,
890 EC_POINT *points[], BN_CTX *ctx)
894 if (group->meth->points_make_affine == 0) {
895 ECerr(EC_F_EC_POINTS_MAKE_AFFINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
898 for (i = 0; i < num; i++) {
899 if (!ec_point_is_compat(points[i], group)) {
900 ECerr(EC_F_EC_POINTS_MAKE_AFFINE, EC_R_INCOMPATIBLE_OBJECTS);
904 return group->meth->points_make_affine(group, num, points, ctx);
908 * Functions for point multiplication. If group->meth->mul is 0, we use the
909 * wNAF-based implementations in ec_mult.c; otherwise we dispatch through
913 int EC_POINTs_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
914 size_t num, const EC_POINT *points[],
915 const BIGNUM *scalars[], BN_CTX *ctx)
919 BN_CTX *new_ctx = NULL;
921 if ((scalar == NULL) && (num == 0)) {
922 return EC_POINT_set_to_infinity(group, r);
925 if (!ec_point_is_compat(r, group)) {
926 ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
929 for (i = 0; i < num; i++) {
930 if (!ec_point_is_compat(points[i], group)) {
931 ECerr(EC_F_EC_POINTS_MUL, EC_R_INCOMPATIBLE_OBJECTS);
936 if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL) {
937 ECerr(EC_F_EC_POINTS_MUL, ERR_R_INTERNAL_ERROR);
941 if (group->meth->mul != NULL)
942 ret = group->meth->mul(group, r, scalar, num, points, scalars, ctx);
945 ret = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
947 BN_CTX_free(new_ctx);
951 int EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *g_scalar,
952 const EC_POINT *point, const BIGNUM *p_scalar, BN_CTX *ctx)
954 /* just a convenient interface to EC_POINTs_mul() */
956 const EC_POINT *points[1];
957 const BIGNUM *scalars[1];
960 scalars[0] = p_scalar;
962 return EC_POINTs_mul(group, r, g_scalar,
964 && p_scalar != NULL), points, scalars, ctx);
967 int EC_GROUP_precompute_mult(EC_GROUP *group, BN_CTX *ctx)
969 if (group->meth->mul == 0)
971 return ec_wNAF_precompute_mult(group, ctx);
973 if (group->meth->precompute_mult != 0)
974 return group->meth->precompute_mult(group, ctx);
976 return 1; /* nothing to do, so report success */
979 int EC_GROUP_have_precompute_mult(const EC_GROUP *group)
981 if (group->meth->mul == 0)
983 return ec_wNAF_have_precompute_mult(group);
985 if (group->meth->have_precompute_mult != 0)
986 return group->meth->have_precompute_mult(group);
988 return 0; /* cannot tell whether precomputation has
993 * ec_precompute_mont_data sets |group->mont_data| from |group->order| and
994 * returns one on success. On error it returns zero.
996 static int ec_precompute_mont_data(EC_GROUP *group)
998 BN_CTX *ctx = BN_CTX_new();
1001 BN_MONT_CTX_free(group->mont_data);
1002 group->mont_data = NULL;
1007 group->mont_data = BN_MONT_CTX_new();
1008 if (group->mont_data == NULL)
1011 if (!BN_MONT_CTX_set(group->mont_data, group->order, ctx)) {
1012 BN_MONT_CTX_free(group->mont_data);
1013 group->mont_data = NULL;
1025 int EC_KEY_set_ex_data(EC_KEY *key, int idx, void *arg)
1027 return CRYPTO_set_ex_data(&key->ex_data, idx, arg);
1030 void *EC_KEY_get_ex_data(const EC_KEY *key, int idx)
1032 return CRYPTO_get_ex_data(&key->ex_data, idx);
1035 int ec_group_simple_order_bits(const EC_GROUP *group)
1037 if (group->order == NULL)
1039 return BN_num_bits(group->order);
1042 static int ec_field_inverse_mod_ord(const EC_GROUP *group, BIGNUM *r,
1043 const BIGNUM *x, BN_CTX *ctx)
1046 BN_CTX *new_ctx = NULL;
1049 if (group->mont_data == NULL)
1052 if (ctx == NULL && (ctx = new_ctx = BN_CTX_secure_new()) == NULL)
1056 if ((e = BN_CTX_get(ctx)) == NULL)
1060 * We want inverse in constant time, therefore we utilize the fact
1061 * order must be prime and use Fermats Little Theorem instead.
1063 if (!BN_set_word(e, 2))
1065 if (!BN_sub(e, group->order, e))
1068 * Exponent e is public.
1069 * No need for scatter-gather or BN_FLG_CONSTTIME.
1071 if (!BN_mod_exp_mont(r, x, e, group->order, ctx, group->mont_data))
1079 BN_CTX_free(new_ctx);
1084 * Default behavior, if group->meth->field_inverse_mod_ord is NULL:
1085 * - When group->order is even, this function returns an error.
1086 * - When group->order is otherwise composite, the correctness
1087 * of the output is not guaranteed.
1088 * - When x is outside the range [1, group->order), the correctness
1089 * of the output is not guaranteed.
1090 * - Otherwise, this function returns the multiplicative inverse in the
1091 * range [1, group->order).
1093 * EC_METHODs must implement their own field_inverse_mod_ord for
1094 * other functionality.
1096 int ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res,
1097 const BIGNUM *x, BN_CTX *ctx)
1099 if (group->meth->field_inverse_mod_ord != NULL)
1100 return group->meth->field_inverse_mod_ord(group, res, x, ctx);
1102 return ec_field_inverse_mod_ord(group, res, x, ctx);
1106 * Coordinate blinding for EC_POINT.
1108 * The underlying EC_METHOD can optionally implement this function:
1109 * underlying implementations should return 0 on errors, or 1 on
1112 * This wrapper returns 1 in case the underlying EC_METHOD does not
1113 * support coordinate blinding.
1115 int ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx)
1117 if (group->meth->blind_coordinates == NULL)
1118 return 1; /* ignore if not implemented */
1120 return group->meth->blind_coordinates(group, p, ctx);