-/* TODO */
/* crypto/ec/ecp_smpl.c */
+/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
+ * for the OpenSSL project. */
/* ====================================================================
* Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
*
*
*/
+#include <openssl/err.h>
+
#include "ec_lcl.h"
{
static const EC_METHOD ret = {
ec_GFp_simple_group_init,
- ec_GFp_simple_group_set_curve_GFp,
ec_GFp_simple_group_finish,
ec_GFp_simple_group_clear_finish,
ec_GFp_simple_group_copy,
+ ec_GFp_simple_group_set_curve_GFp,
+ ec_GFp_simple_group_get_curve_GFp,
ec_GFp_simple_group_set_generator,
- /* TODO: 'set' and 'get' functions for EC_GROUPs */
+ ec_GFp_simple_group_get0_generator,
+ ec_GFp_simple_group_get_order,
+ ec_GFp_simple_group_get_cofactor,
ec_GFp_simple_point_init,
ec_GFp_simple_point_finish,
ec_GFp_simple_point_clear_finish,
ec_GFp_simple_point_copy,
- /* TODO: 'set' and 'get' functions for EC_POINTs */
+ ec_GFp_simple_point_set_to_infinity,
+ ec_GFp_simple_set_Jprojective_coordinates_GFp,
+ ec_GFp_simple_get_Jprojective_coordinates_GFp,
+ ec_GFp_simple_point_set_affine_coordinates_GFp,
+ ec_GFp_simple_point_get_affine_coordinates_GFp,
+ ec_GFp_simple_set_compressed_coordinates_GFp,
ec_GFp_simple_point2oct,
ec_GFp_simple_oct2point,
ec_GFp_simple_add,
ec_GFp_simple_dbl,
+ ec_GFp_simple_invert,
ec_GFp_simple_is_at_infinity,
ec_GFp_simple_is_on_curve,
+ ec_GFp_simple_cmp,
ec_GFp_simple_make_affine,
- ec_GFp_simple_field_mult,
+ ec_GFp_simple_field_mul,
ec_GFp_simple_field_sqr,
0 /* field_encode */,
0 /* field_decode */ };
return &ret;
}
+
+
+int ec_GFp_simple_group_init(EC_GROUP *group)
+ {
+ BN_init(&group->field);
+ BN_init(&group->a);
+ BN_init(&group->b);
+ group->a_is_minus3 = 0;
+ group->generator = NULL;
+ BN_init(&group->order);
+ BN_init(&group->cofactor);
+ return 1;
+ }
+
+
+void ec_GFp_simple_group_finish(EC_GROUP *group)
+ {
+ BN_free(&group->field);
+ BN_free(&group->a);
+ BN_free(&group->b);
+ if (group->generator != NULL)
+ EC_POINT_free(group->generator);
+ BN_free(&group->order);
+ BN_free(&group->cofactor);
+ }
+
+
+void ec_GFp_simple_group_clear_finish(EC_GROUP *group)
+ {
+ BN_clear_free(&group->field);
+ BN_clear_free(&group->a);
+ BN_clear_free(&group->b);
+ if (group->generator != NULL)
+ {
+ EC_POINT_clear_free(group->generator);
+ group->generator = NULL;
+ }
+ BN_clear_free(&group->order);
+ BN_clear_free(&group->cofactor);
+ }
+
+
+int ec_GFp_simple_group_copy(EC_GROUP *dest, const EC_GROUP *src)
+ {
+ if (!BN_copy(&dest->field, &src->field)) return 0;
+ if (!BN_copy(&dest->a, &src->a)) return 0;
+ if (!BN_copy(&dest->b, &src->b)) return 0;
+
+ dest->a_is_minus3 = src->a_is_minus3;
+
+ if (src->generator != NULL)
+ {
+ if (dest->generator == NULL)
+ {
+ dest->generator = EC_POINT_new(dest);
+ if (dest->generator == NULL) return 0;
+ }
+ if (!EC_POINT_copy(dest->generator, src->generator)) return 0;
+ }
+ else
+ {
+ /* src->generator == NULL */
+ if (dest->generator != NULL)
+ {
+ EC_POINT_clear_free(dest->generator);
+ dest->generator = NULL;
+ }
+ }
+
+ if (!BN_copy(&dest->order, &src->order)) return 0;
+ if (!BN_copy(&dest->cofactor, &src->cofactor)) return 0;
+
+ return 1;
+ }
+
+
+int ec_GFp_simple_group_set_curve_GFp(EC_GROUP *group,
+ const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
+ {
+ int ret = 0;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp_a;
+
+ /* p must be a prime > 3 */
+ if (BN_num_bits(p) <= 2 || !BN_is_odd(p))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE_GFP, EC_R_INVALID_FIELD);
+ return 0;
+ }
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ tmp_a = BN_CTX_get(ctx);
+ if (tmp_a == NULL) goto err;
+
+ /* group->field */
+ if (!BN_copy(&group->field, p)) goto err;
+ group->field.neg = 0;
+
+ /* group->a */
+ if (!BN_nnmod(tmp_a, a, p, ctx)) goto err;
+ if (group->meth->field_encode)
+ { if (!group->meth->field_encode(group, &group->a, tmp_a, ctx)) goto err; }
+ else
+ if (!BN_copy(&group->a, tmp_a)) goto err;
+
+ /* group->b */
+ if (!BN_nnmod(&group->b, b, p, ctx)) goto err;
+ if (group->meth->field_encode)
+ if (!group->meth->field_encode(group, &group->b, &group->b, ctx)) goto err;
+
+ /* group->a_is_minus3 */
+ if (!BN_add_word(tmp_a, 3)) goto err;
+ group->a_is_minus3 = (0 == BN_cmp(tmp_a, &group->field));
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_group_get_curve_GFp(EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
+ {
+ int ret = 0;
+ BN_CTX *new_ctx = NULL;
+
+ if (p != NULL)
+ {
+ if (!BN_copy(p, &group->field)) return 0;
+ }
+
+ if (a != NULL || b != NULL)
+ {
+ if (group->meth->field_decode)
+ {
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+ if (a != NULL)
+ {
+ if (!group->meth->field_decode(group, a, &group->a, ctx)) goto err;
+ }
+ if (b != NULL)
+ {
+ if (!group->meth->field_decode(group, b, &group->b, ctx)) goto err;
+ }
+ }
+ else
+ {
+ if (a != NULL)
+ {
+ if (!BN_copy(a, &group->a)) goto err;
+ }
+ if (b != NULL)
+ {
+ if (!BN_copy(b, &group->b)) goto err;
+ }
+ }
+ }
+
+ ret = 1;
+
+ err:
+ if (new_ctx)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+
+int ec_GFp_simple_group_set_generator(EC_GROUP *group, const EC_POINT *generator,
+ const BIGNUM *order, const BIGNUM *cofactor)
+ {
+ if (generator)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
+ return 0 ;
+ }
+
+ if (group->generator == NULL)
+ {
+ group->generator = EC_POINT_new(group);
+ if (group->generator == NULL) return 0;
+ }
+ if (!EC_POINT_copy(group->generator, generator)) return 0;
+
+ if (order != NULL)
+ { if (!BN_copy(&group->order, order)) return 0; }
+ else
+ { if (!BN_zero(&group->order)) return 0; }
+
+ if (cofactor != NULL)
+ { if (!BN_copy(&group->cofactor, cofactor)) return 0; }
+ else
+ { if (!BN_zero(&group->cofactor)) return 0; }
+
+ return 1;
+ }
+
+
+EC_POINT *ec_GFp_simple_group_get0_generator(EC_GROUP *group)
+ {
+ return group->generator;
+ }
+
+
+int ec_GFp_simple_group_get_order(EC_GROUP *group, BIGNUM *order, BN_CTX *ctx)
+ {
+ if (!BN_copy(order, &group->order))
+ return 0;
+
+ return !BN_is_zero(&group->order);
+ }
+
+
+int ec_GFp_simple_group_get_cofactor(EC_GROUP *group, BIGNUM *cofactor, BN_CTX *ctx)
+ {
+ if (!BN_copy(cofactor, &group->cofactor))
+ return 0;
+
+ return !BN_is_zero(&group->cofactor);
+ }
+
+
+int ec_GFp_simple_point_init(EC_POINT *point)
+ {
+ BN_init(&point->X);
+ BN_init(&point->Y);
+ BN_init(&point->Z);
+ point->Z_is_one = 0;
+
+ return 1;
+ }
+
+
+void ec_GFp_simple_point_finish(EC_POINT *point)
+ {
+ BN_free(&point->X);
+ BN_free(&point->Y);
+ BN_free(&point->Z);
+ }
+
+
+void ec_GFp_simple_point_clear_finish(EC_POINT *point)
+ {
+ BN_clear_free(&point->X);
+ BN_clear_free(&point->Y);
+ BN_clear_free(&point->Z);
+ point->Z_is_one = 0;
+ }
+
+
+int ec_GFp_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
+ {
+ if (!BN_copy(&dest->X, &src->X)) return 0;
+ if (!BN_copy(&dest->Y, &src->Y)) return 0;
+ if (!BN_copy(&dest->Z, &src->Z)) return 0;
+ dest->Z_is_one = src->Z_is_one;
+
+ return 1;
+ }
+
+
+int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
+ {
+ point->Z_is_one = 0;
+ return (BN_zero(&point->Z));
+ }
+
+
+int ec_GFp_simple_set_Jprojective_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
+ const BIGNUM *x, const BIGNUM *y, const BIGNUM *z, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ int ret = 0;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ if (x != NULL)
+ {
+ if (!BN_nnmod(&point->X, x, &group->field, ctx)) goto err;
+ if (group->meth->field_encode)
+ {
+ if (!group->meth->field_encode(group, &point->X, &point->X, ctx)) goto err;
+ }
+ }
+
+ if (y != NULL)
+ {
+ if (!BN_nnmod(&point->Y, y, &group->field, ctx)) goto err;
+ if (group->meth->field_encode)
+ {
+ if (!group->meth->field_encode(group, &point->Y, &point->Y, ctx)) goto err;
+ }
+ }
+
+ if (z != NULL)
+ {
+ int Z_is_one;
+
+ if (!BN_nnmod(&point->Z, z, &group->field, ctx)) goto err;
+ Z_is_one = BN_is_one(&point->Z);
+ if (group->meth->field_encode)
+ {
+ if (!group->meth->field_encode(group, &point->Z, &point->Z, ctx)) goto err;
+ }
+ point->Z_is_one = Z_is_one;
+ }
+
+ ret = 1;
+
+ err:
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
+ BIGNUM *x, BIGNUM *y, BIGNUM *z, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ int ret = 0;
+
+ if (group->meth->field_decode != 0)
+ {
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ if (x != NULL)
+ {
+ if (!group->meth->field_decode(group, x, &point->X, ctx)) goto err;
+ }
+ if (y != NULL)
+ {
+ if (!group->meth->field_decode(group, y, &point->Y, ctx)) goto err;
+ }
+ if (z != NULL)
+ {
+ if (!group->meth->field_decode(group, z, &point->Z, ctx)) goto err;
+ }
+ }
+ else
+ {
+ if (x != NULL)
+ {
+ if (!BN_copy(x, &point->X)) goto err;
+ }
+ if (y != NULL)
+ {
+ if (!BN_copy(y, &point->Y)) goto err;
+ }
+ if (z != NULL)
+ {
+ if (!BN_copy(z, &point->Z)) goto err;
+ }
+ }
+
+ ret = 1;
+
+ err:
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_point_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
+ const BIGNUM *x, const BIGNUM *y, BN_CTX *ctx)
+ {
+ if (x == NULL || y == NULL)
+ {
+ /* unlike for projective coordinates, we do not tolerate this */
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT_SET_AFFINE_COORDINATES_GFP, ERR_R_PASSED_NULL_PARAMETER);
+ return 0;
+ }
+
+ return EC_POINT_set_Jprojective_coordinates_GFp(group, point, x, y, BN_value_one(), ctx);
+ }
+
+
+int ec_GFp_simple_point_get_affine_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
+ BIGNUM *x, BIGNUM *y, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *X, *Y, *Z, *Z_1, *Z_2, *Z_3;
+ const BIGNUM *X_, *Y_, *Z_;
+ int ret = 0;
+
+ if (EC_POINT_is_at_infinity(group, point))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES_GFP, EC_R_POINT_AT_INFINITY);
+ return 0;
+ }
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ X = BN_CTX_get(ctx);
+ Y = BN_CTX_get(ctx);
+ Z = BN_CTX_get(ctx);
+ Z_1 = BN_CTX_get(ctx);
+ Z_2 = BN_CTX_get(ctx);
+ Z_3 = BN_CTX_get(ctx);
+ if (Z_3 == NULL) goto err;
+
+ /* transform (X, Y, Z) into (x, y) := (X/Z^2, Y/Z^3) */
+
+ if (group->meth->field_decode)
+ {
+ if (!group->meth->field_decode(group, X, &point->X, ctx)) goto err;
+ if (!group->meth->field_decode(group, Y, &point->Y, ctx)) goto err;
+ if (!group->meth->field_decode(group, Z, &point->Z, ctx)) goto err;
+ X_ = X; Y_ = Y; Z_ = Z;
+ }
+ else
+ {
+ X_ = &point->X;
+ Y_ = &point->Y;
+ Z_ = &point->Z;
+ }
+
+ if (BN_is_one(Z_))
+ {
+ if (x != NULL)
+ {
+ if (!BN_copy(x, X_)) goto err;
+ }
+ if (y != NULL)
+ {
+ if (!BN_copy(y, Y_)) goto err;
+ }
+ }
+ else
+ {
+ if (!BN_mod_inverse(Z_1, Z_, &group->field, ctx))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES_GFP, ERR_R_BN_LIB);
+ goto err;
+ }
+ if (!BN_mod_sqr(Z_2, Z_1, &group->field, ctx)) goto err;
+
+ if (x != NULL)
+ {
+ if (!BN_mod_mul(x, X_, Z_2, &group->field, ctx)) goto err;
+ }
+
+ if (y != NULL)
+ {
+ if (!BN_mod_mul(Z_3, Z_2, Z_1, &group->field, ctx)) goto err;
+ if (!BN_mod_mul(y, Y_, Z_3, &group->field, ctx)) goto err;
+ }
+ }
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_set_compressed_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
+ const BIGNUM *x, int y_bit, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp1, *tmp2, *y;
+ int ret = 0;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ y_bit = (y_bit != 0);
+
+ BN_CTX_start(ctx);
+ tmp1 = BN_CTX_get(ctx);
+ tmp2 = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL) goto err;
+
+ /* Recover y. We have a Weierstrass equation
+ * y^2 = x^3 + a*x + b,
+ * so y is one of the square roots of x^3 + a*x + b.
+ */
+
+ /* tmp1 := x^3 */
+ if (!BN_mod_sqr(tmp2, x, &group->field, ctx)) goto err;
+ if (!BN_mod_mul(tmp1, tmp2, x, &group->field, ctx)) goto err;
+
+ /* tmp1 := tmp1 + a*x */
+ if (group->a_is_minus3)
+ {
+ if (!BN_mod_lshift1_quick(tmp2, x, &group->field)) goto err;
+ if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field)) goto err;
+ if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
+ }
+ else
+ {
+ if (group->meth->field_decode)
+ {
+ if (!group->meth->field_decode(group, tmp2, &group->a, ctx)) goto err;
+ if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_mod_mul(tmp2, &group->a, x, &group->field, ctx)) goto err;
+ }
+
+ if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
+ }
+
+ /* tmp1 := tmp1 + b */
+ if (group->meth->field_decode)
+ {
+ if (!group->meth->field_decode(group, tmp2, &group->b, ctx)) goto err;
+ if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
+ }
+ else
+ {
+ if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) goto err;
+ }
+
+ if (!BN_mod_sqrt(y, tmp1, &group->field, ctx))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, ERR_R_BN_LIB);
+ goto err;
+ }
+ /* If tmp1 is not a square (i.e. there is no point on the curve with
+ * our x), then y now is a nonsense value too */
+
+ if (y_bit != BN_is_odd(y))
+ {
+ if (BN_is_zero(y))
+ {
+ int kron;
+
+ kron = BN_kronecker(x, &group->field, ctx);
+ if (kron == -2) goto err;
+
+ if (kron == 1)
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, EC_R_INVALID_COMPRESSION_BIT);
+ else
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, EC_R_INVALID_COMPRESSED_POINT);
+ goto err;
+ }
+ if (!BN_usub(y, &group->field, y)) goto err;
+ }
+ if (y_bit != BN_is_odd(y))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES_GFP, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
+ unsigned char *buf, size_t len, BN_CTX *ctx)
+ {
+ size_t ret;
+ BN_CTX *new_ctx = NULL;
+ int used_ctx = 0;
+ BIGNUM *x, *y;
+ size_t field_len, i, skip;
+
+ if ((form != POINT_CONVERSION_COMPRESSED)
+ && (form != POINT_CONVERSION_UNCOMPRESSED)
+ && (form != POINT_CONVERSION_HYBRID))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
+ goto err;
+ }
+
+ if (EC_POINT_is_at_infinity(group, point))
+ {
+ /* encodes to a single 0 octet */
+ if (buf != NULL)
+ {
+ if (len < 1)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+ buf[0] = 0;
+ }
+ return 1;
+ }
+
+
+ /* ret := required output buffer length */
+ field_len = BN_num_bytes(&group->field);
+ ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
+
+ /* if 'buf' is NULL, just return required length */
+ if (buf != NULL)
+ {
+ if (len < ret)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
+ goto err;
+ }
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ used_ctx = 1;
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL) goto err;
+
+ if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+
+ if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
+ buf[0] = form + 1;
+ else
+ buf[0] = form;
+
+ i = 1;
+
+ skip = field_len - BN_num_bytes(x);
+ if (skip > field_len)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ while (skip > 0)
+ {
+ buf[i++] = 0;
+ skip--;
+ }
+ skip = BN_bn2bin(x, buf + i);
+ i += skip;
+ if (i != 1 + field_len)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
+ {
+ skip = field_len - BN_num_bytes(y);
+ if (skip > field_len)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ while (skip > 0)
+ {
+ buf[i++] = 0;
+ skip--;
+ }
+ skip = BN_bn2bin(y, buf + i);
+ i += skip;
+ }
+
+ if (i != ret)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ }
+
+ if (used_ctx)
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+
+ err:
+ if (used_ctx)
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return 0;
+ }
+
+
+int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
+ const unsigned char *buf, size_t len, BN_CTX *ctx)
+ {
+ point_conversion_form_t form;
+ int y_bit;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *x, *y;
+ size_t field_len, enc_len;
+ int ret = 0;
+
+ if (len <= 0)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
+ return 0;
+ }
+ form = buf[0];
+ y_bit = form & 1;
+ form = form & ~1;
+ if ((form != 0) && (form != POINT_CONVERSION_COMPRESSED)
+ && (form != POINT_CONVERSION_UNCOMPRESSED)
+ && (form != POINT_CONVERSION_HYBRID))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+ if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ if (form == 0)
+ {
+ if (len != 1)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ return EC_POINT_set_to_infinity(group, point);
+ }
+
+ field_len = BN_num_bytes(&group->field);
+ enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;
+
+ if (len != enc_len)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL) goto err;
+
+ if (!BN_bin2bn(buf + 1, field_len, x)) goto err;
+ if (BN_ucmp(x, &group->field) >= 0)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ goto err;
+ }
+
+ if (form == POINT_CONVERSION_COMPRESSED)
+ {
+ if (!EC_POINT_set_compressed_coordinates_GFp(group, point, x, y_bit, ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_bin2bn(buf + 1 + field_len, field_len, y)) goto err;
+ if (BN_ucmp(y, &group->field) >= 0)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ goto err;
+ }
+ if (form == POINT_CONVERSION_HYBRID)
+ {
+ if (y_bit != BN_is_odd(y))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
+ goto err;
+ }
+ }
+
+ if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+ }
+
+ if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
+ goto err;
+ }
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
+ {
+ int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+ int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+ const BIGNUM *p;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6;
+ int ret = 0;
+
+ if (a == b)
+ return EC_POINT_dbl(group, r, a, ctx);
+ if (EC_POINT_is_at_infinity(group, a))
+ return EC_POINT_copy(r, b);
+ if (EC_POINT_is_at_infinity(group, b))
+ return EC_POINT_copy(r, a);
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+ p = &group->field;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ n0 = BN_CTX_get(ctx);
+ n1 = BN_CTX_get(ctx);
+ n2 = BN_CTX_get(ctx);
+ n3 = BN_CTX_get(ctx);
+ n4 = BN_CTX_get(ctx);
+ n5 = BN_CTX_get(ctx);
+ n6 = BN_CTX_get(ctx);
+ if (n6 == NULL) goto end;
+
+ /* Note that in this function we must not read components of 'a' or 'b'
+ * once we have written the corresponding components of 'r'.
+ * ('r' might be one of 'a' or 'b'.)
+ */
+
+ /* n1, n2 */
+ if (b->Z_is_one)
+ {
+ if (!BN_copy(n1, &a->X)) goto end;
+ if (!BN_copy(n2, &a->Y)) goto end;
+ /* n1 = X_a */
+ /* n2 = Y_a */
+ }
+ else
+ {
+ if (!field_sqr(group, n0, &b->Z, ctx)) goto end;
+ if (!field_mul(group, n1, &a->X, n0, ctx)) goto end;
+ /* n1 = X_a * Z_b^2 */
+
+ if (!field_mul(group, n0, n0, &b->Z, ctx)) goto end;
+ if (!field_mul(group, n2, &a->Y, n0, ctx)) goto end;
+ /* n2 = Y_a * Z_b^3 */
+ }
+
+ /* n3, n4 */
+ if (a->Z_is_one)
+ {
+ if (!BN_copy(n3, &b->X)) goto end;
+ if (!BN_copy(n4, &b->Y)) goto end;
+ /* n3 = X_b */
+ /* n4 = Y_b */
+ }
+ else
+ {
+ if (!field_sqr(group, n0, &a->Z, ctx)) goto end;
+ if (!field_mul(group, n3, &b->X, n0, ctx)) goto end;
+ /* n3 = X_b * Z_a^2 */
+
+ if (!field_mul(group, n0, n0, &a->Z, ctx)) goto end;
+ if (!field_mul(group, n4, &b->Y, n0, ctx)) goto end;
+ /* n4 = Y_b * Z_a^3 */
+ }
+
+ /* n5, n6 */
+ if (!BN_mod_sub_quick(n5, n1, n3, p)) goto end;
+ if (!BN_mod_sub_quick(n6, n2, n4, p)) goto end;
+ /* n5 = n1 - n3 */
+ /* n6 = n2 - n4 */
+
+ if (BN_is_zero(n5))
+ {
+ if (BN_is_zero(n6))
+ {
+ /* a is the same point as b */
+ BN_CTX_end(ctx);
+ ret = EC_POINT_dbl(group, r, a, ctx);
+ ctx = NULL;
+ goto end;
+ }
+ else
+ {
+ /* a is the inverse of b */
+ if (!BN_zero(&r->Z)) goto end;
+ r->Z_is_one = 0;
+ ret = 1;
+ goto end;
+ }
+ }
+
+ /* 'n7', 'n8' */
+ if (!BN_mod_add_quick(n1, n1, n3, p)) goto end;
+ if (!BN_mod_add_quick(n2, n2, n4, p)) goto end;
+ /* 'n7' = n1 + n3 */
+ /* 'n8' = n2 + n4 */
+
+ /* Z_r */
+ if (a->Z_is_one && b->Z_is_one)
+ {
+ if (!BN_copy(&r->Z, n5)) goto end;
+ }
+ else
+ {
+ if (a->Z_is_one)
+ { if (!BN_copy(n0, &b->Z)) goto end; }
+ else if (b->Z_is_one)
+ { if (!BN_copy(n0, &a->Z)) goto end; }
+ else
+ { if (!field_mul(group, n0, &a->Z, &b->Z, ctx)) goto end; }
+ if (!field_mul(group, &r->Z, n0, n5, ctx)) goto end;
+ }
+ r->Z_is_one = 0;
+ /* Z_r = Z_a * Z_b * n5 */
+
+ /* X_r */
+ if (!field_sqr(group, n0, n6, ctx)) goto end;
+ if (!field_sqr(group, n4, n5, ctx)) goto end;
+ if (!field_mul(group, n3, n1, n4, ctx)) goto end;
+ if (!BN_mod_sub_quick(&r->X, n0, n3, p)) goto end;
+ /* X_r = n6^2 - n5^2 * 'n7' */
+
+ /* 'n9' */
+ if (!BN_mod_lshift1_quick(n0, &r->X, p)) goto end;
+ if (!BN_mod_sub_quick(n0, n3, n0, p)) goto end;
+ /* n9 = n5^2 * 'n7' - 2 * X_r */
+
+ /* Y_r */
+ if (!field_mul(group, n0, n0, n6, ctx)) goto end;
+ if (!field_mul(group, n5, n4, n5, ctx)) goto end; /* now n5 is n5^3 */
+ if (!field_mul(group, n1, n2, n5, ctx)) goto end;
+ if (!BN_mod_sub_quick(n0, n0, n1, p)) goto end;
+ if (BN_is_odd(n0))
+ if (!BN_add(n0, n0, p)) goto end;
+ /* now 0 <= n0 < 2*p, and n0 is even */
+ if (!BN_rshift1(&r->Y, n0)) goto end;
+ /* Y_r = (n6 * 'n9' - 'n8' * 'n5^3') / 2 */
+
+ ret = 1;
+
+ end:
+ if (ctx) /* otherwise we already called BN_CTX_end */
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx)
+ {
+ int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+ int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+ const BIGNUM *p;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *n0, *n1, *n2, *n3;
+ int ret = 0;
+
+ if (EC_POINT_is_at_infinity(group, a))
+ {
+ if (!BN_zero(&r->Z)) return 0;
+ r->Z_is_one = 0;
+ return 1;
+ }
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+ p = &group->field;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ n0 = BN_CTX_get(ctx);
+ n1 = BN_CTX_get(ctx);
+ n2 = BN_CTX_get(ctx);
+ n3 = BN_CTX_get(ctx);
+ if (n3 == NULL) goto err;
+
+ /* Note that in this function we must not read components of 'a'
+ * once we have written the corresponding components of 'r'.
+ * ('r' might the same as 'a'.)
+ */
+
+ /* n1 */
+ if (a->Z_is_one)
+ {
+ if (!field_sqr(group, n0, &a->X, ctx)) goto err;
+ if (!BN_mod_lshift1_quick(n1, n0, p)) goto err;
+ if (!BN_mod_add_quick(n0, n0, n1, p)) goto err;
+ if (!BN_mod_add_quick(n1, n0, &group->a, p)) goto err;
+ /* n1 = 3 * X_a^2 + a_curve */
+ }
+ else if (group->a_is_minus3)
+ {
+ if (!field_sqr(group, n1, &a->Z, ctx)) goto err;
+ if (!BN_mod_add_quick(n0, &a->X, n1, p)) goto err;
+ if (!BN_mod_sub_quick(n2, &a->X, n1, p)) goto err;
+ if (!field_mul(group, n1, n0, n2, ctx)) goto err;
+ if (!BN_mod_lshift1_quick(n0, n1, p)) goto err;
+ if (!BN_mod_add_quick(n1, n0, n1, p)) goto err;
+ /* n1 = 3 * (X_a + Z_a^2) * (X_a - Z_a^2)
+ * = 3 * X_a^2 - 3 * Z_a^4 */
+ }
+ else
+ {
+ if (!field_sqr(group, n0, &a->X, ctx)) goto err;
+ if (!BN_mod_lshift1_quick(n1, n0, p)) goto err;
+ if (!BN_mod_add_quick(n0, n0, n1, p)) goto err;
+ if (!field_sqr(group, n1, &a->Z, ctx)) goto err;
+ if (!field_sqr(group, n1, n1, ctx)) goto err;
+ if (!field_mul(group, n1, n1, &group->a, ctx)) goto err;
+ if (!BN_mod_add_quick(n1, n1, n0, p)) goto err;
+ /* n1 = 3 * X_a^2 + a_curve * Z_a^4 */
+ }
+
+ /* Z_r */
+ if (a->Z_is_one)
+ {
+ if (!BN_copy(n0, &a->Y)) goto err;
+ }
+ else
+ {
+ if (!field_mul(group, n0, &a->Y, &a->Z, ctx)) goto err;
+ }
+ if (!BN_mod_lshift1_quick(&r->Z, n0, p)) goto err;
+ r->Z_is_one = 0;
+ /* Z_r = 2 * Y_a * Z_a */
+
+ /* n2 */
+ if (!field_sqr(group, n3, &a->Y, ctx)) goto err;
+ if (!field_mul(group, n2, &a->X, n3, ctx)) goto err;
+ if (!BN_mod_lshift_quick(n2, n2, 2, p)) goto err;
+ /* n2 = 4 * X_a * Y_a^2 */
+
+ /* X_r */
+ if (!BN_mod_lshift1_quick(n0, n2, p)) goto err;
+ if (!field_sqr(group, &r->X, n1, ctx)) goto err;
+ if (!BN_mod_sub_quick(&r->X, &r->X, n0, p)) goto err;
+ /* X_r = n1^2 - 2 * n2 */
+
+ /* n3 */
+ if (!field_sqr(group, n0, n3, ctx)) goto err;
+ if (!BN_mod_lshift_quick(n3, n0, 3, p)) goto err;
+ /* n3 = 8 * Y_a^4 */
+
+ /* Y_r */
+ if (!BN_mod_sub_quick(n0, n2, &r->X, p)) goto err;
+ if (!field_mul(group, n0, n1, n0, ctx)) goto err;
+ if (!BN_mod_sub_quick(&r->Y, n0, n3, p)) goto err;
+ /* Y_r = n1 * (n2 - X_r) - n3 */
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_invert(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
+ {
+ if (EC_POINT_is_at_infinity(group, point) || BN_is_zero(&point->Y))
+ /* point is its own inverse */
+ return 1;
+
+ return BN_usub(&point->Y, &group->field, &point->Y);
+ }
+
+
+int ec_GFp_simple_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
+ {
+ return BN_is_zero(&point->Z);
+ }
+
+
+int ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx)
+ {
+ int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+ int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+ const BIGNUM *p;
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *rh, *tmp1, *tmp2, *Z4, *Z6;
+ int ret = -1;
+
+ if (EC_POINT_is_at_infinity(group, point))
+ return 1;
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+ p = &group->field;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return -1;
+ }
+
+ BN_CTX_start(ctx);
+ rh = BN_CTX_get(ctx);
+ tmp1 = BN_CTX_get(ctx);
+ tmp2 = BN_CTX_get(ctx);
+ Z4 = BN_CTX_get(ctx);
+ Z6 = BN_CTX_get(ctx);
+ if (Z6 == NULL) goto err;
+
+ /* We have a curve defined by a Weierstrass equation
+ * y^2 = x^3 + a*x + b.
+ * The point to consider is given in Jacobian projective coordinates
+ * where (X, Y, Z) represents (x, y) = (X/Z^2, Y/Z^3).
+ * Substituting this and multiplying by Z^6 transforms the above equation into
+ * Y^2 = X^3 + a*X*Z^4 + b*Z^6.
+ * To test this, we add up the right-hand side in 'rh'.
+ */
+
+ /* rh := X^3 */
+ if (!field_sqr(group, rh, &point->X, ctx)) goto err;
+ if (!field_mul(group, rh, rh, &point->X, ctx)) goto err;
+
+ if (!point->Z_is_one)
+ {
+ if (!field_sqr(group, tmp1, &point->Z, ctx)) goto err;
+ if (!field_sqr(group, Z4, tmp1, ctx)) goto err;
+ if (!field_mul(group, Z6, Z4, tmp1, ctx)) goto err;
+
+ /* rh := rh + a*X*Z^4 */
+ if (!field_mul(group, tmp1, &point->X, Z4, ctx)) goto err;
+ if (group->a_is_minus3)
+ {
+ if (!BN_mod_lshift1_quick(tmp2, tmp1, p)) goto err;
+ if (!BN_mod_add_quick(tmp2, tmp2, tmp1, p)) goto err;
+ if (!BN_mod_sub_quick(rh, rh, tmp2, p)) goto err;
+ }
+ else
+ {
+ if (!field_mul(group, tmp2, tmp1, &group->a, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp2, p)) goto err;
+ }
+
+ /* rh := rh + b*Z^6 */
+ if (!field_mul(group, tmp1, &group->b, Z6, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp1, p)) goto err;
+ }
+ else
+ {
+ /* point->Z_is_one */
+
+ /* rh := rh + a*X */
+ if (group->a_is_minus3)
+ {
+ if (!BN_mod_lshift1_quick(tmp2, &point->X, p)) goto err;
+ if (!BN_mod_add_quick(tmp2, tmp2, &point->X, p)) goto err;
+ if (!BN_mod_sub_quick(rh, rh, tmp2, p)) goto err;
+ }
+ else
+ {
+ if (!field_mul(group, tmp2, &point->X, &group->a, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp2, p)) goto err;
+ }
+
+ /* rh := rh + b */
+ if (!BN_mod_add_quick(rh, rh, &group->b, p)) goto err;
+ }
+
+ /* 'lh' := Y^2 */
+ if (!field_sqr(group, tmp1, &point->Y, ctx)) goto err;
+
+ ret = (0 == BN_cmp(tmp1, rh));
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx)
+ {
+ /* return values:
+ * -1 error
+ * 0 equal (in affine coordinates)
+ * 1 not equal
+ */
+
+ int (*field_mul)(const EC_GROUP *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
+ int (*field_sqr)(const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp1, *tmp2, *Za23, *Zb23;
+ const BIGNUM *tmp1_, *tmp2_;
+ int ret = -1;
+
+ if (EC_POINT_is_at_infinity(group, a))
+ {
+ return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
+ }
+
+ if (a->Z_is_one && b->Z_is_one)
+ {
+ return ((BN_cmp(&a->X, &b->X) == 0) && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;
+ }
+
+ field_mul = group->meth->field_mul;
+ field_sqr = group->meth->field_sqr;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return -1;
+ }
+
+ BN_CTX_start(ctx);
+ tmp1 = BN_CTX_get(ctx);
+ tmp2 = BN_CTX_get(ctx);
+ Za23 = BN_CTX_get(ctx);
+ Zb23 = BN_CTX_get(ctx);
+ if (Zb23 == NULL) goto end;
+
+ /* We have to decide whether
+ * (X_a/Z_a^2, Y_a/Z_a^3) = (X_b/Z_b^2, Y_b/Z_b^3),
+ * or equivalently, whether
+ * (X_a*Z_b^2, Y_a*Z_b^3) = (X_b*Z_a^2, Y_b*Z_a^3).
+ */
+
+ if (!b->Z_is_one)
+ {
+ if (!field_sqr(group, Zb23, &b->Z, ctx)) goto end;
+ if (!field_mul(group, tmp1, &a->X, Zb23, ctx)) goto end;
+ tmp1_ = tmp1;
+ }
+ else
+ tmp1_ = &a->X;
+ if (!a->Z_is_one)
+ {
+ if (!field_sqr(group, Za23, &a->Z, ctx)) goto end;
+ if (!field_mul(group, tmp2, &b->X, Za23, ctx)) goto end;
+ tmp2_ = tmp2;
+ }
+ else
+ tmp2_ = &b->X;
+
+ /* compare X_a*Z_b^2 with X_b*Z_a^2 */
+ if (BN_cmp(tmp1_, tmp2_) != 0)
+ {
+ ret = 1; /* points differ */
+ goto end;
+ }
+
+
+ if (!b->Z_is_one)
+ {
+ if (!field_mul(group, Zb23, Zb23, &b->Z, ctx)) goto end;
+ if (!field_mul(group, tmp1, &a->Y, Zb23, ctx)) goto end;
+ /* tmp1_ = tmp1 */
+ }
+ else
+ tmp1_ = &a->Y;
+ if (!a->Z_is_one)
+ {
+ if (!field_mul(group, Za23, Za23, &a->Z, ctx)) goto end;
+ if (!field_mul(group, tmp2, &b->Y, Za23, ctx)) goto end;
+ /* tmp2_ = tmp2 */
+ }
+ else
+ tmp2_ = &b->Y;
+
+ /* compare Y_a*Z_b^3 with Y_b*Z_a^3 */
+ if (BN_cmp(tmp1_, tmp2_) != 0)
+ {
+ ret = 1; /* points differ */
+ goto end;
+ }
+
+ /* points are equal */
+ ret = 0;
+
+ end:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *x, *y;
+ int ret = 0;
+
+ if (point->Z_is_one || EC_POINT_is_at_infinity(group, point))
+ return 1;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ x = BN_CTX_get(ctx);
+ y = BN_CTX_get(ctx);
+ if (y == NULL) goto err;
+
+ if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+ if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
+ if (!point->Z_is_one)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_MAKE_AFFINE, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
+ }
+
+
+int ec_GFp_simple_field_mul(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
+ {
+ return BN_mod_mul(r, a, b, &group->field, ctx);
+ }
+
+
+int ec_GFp_simple_field_sqr(const EC_GROUP *group, BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
+ {
+ return BN_mod_sqr(r, a, &group->field, ctx);
+ }
projects / openssl.git / blobdiff