/* crypto/ec/ecp_smpl.c */
/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
- * for the OpenSSL project. */
+ * for the OpenSSL project.
+ * Includes code written by Bodo Moeller for the OpenSSL project.
+*/
/* ====================================================================
- * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
+ * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* Hudson (tjh@cryptsoft.com).
*
*/
+/* ====================================================================
+ * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
+ * Portions of this software developed by SUN MICROSYSTEMS, INC.,
+ * and contributed to the OpenSSL project.
+ */
+
+#define OPENSSL_FIPSAPI
#include <openssl/err.h>
+#include <openssl/symhacks.h>
#include "ec_lcl.h"
-
const EC_METHOD *EC_GFp_simple_method(void)
{
static const EC_METHOD ret = {
+ EC_FLAGS_DEFAULT_OCT,
+ NID_X9_62_prime_field,
ec_GFp_simple_group_init,
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,
- ec_GFp_simple_group_get0_generator,
- ec_GFp_simple_group_get_order,
- ec_GFp_simple_group_get_cofactor,
+ ec_GFp_simple_group_set_curve,
+ ec_GFp_simple_group_get_curve,
+ ec_GFp_simple_group_get_degree,
+ ec_GFp_simple_group_check_discriminant,
ec_GFp_simple_point_init,
ec_GFp_simple_point_finish,
ec_GFp_simple_point_clear_finish,
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_point_set_affine_coordinates,
+ ec_GFp_simple_point_get_affine_coordinates,
+ 0,0,0,
ec_GFp_simple_add,
ec_GFp_simple_dbl,
ec_GFp_simple_invert,
ec_GFp_simple_is_on_curve,
ec_GFp_simple_cmp,
ec_GFp_simple_make_affine,
+ ec_GFp_simple_points_make_affine,
+ 0 /* mul */,
+ 0 /* precompute_mult */,
+ 0 /* have_precompute_mult */,
ec_GFp_simple_field_mul,
ec_GFp_simple_field_sqr,
+ 0 /* field_div */,
0 /* field_encode */,
- 0 /* field_decode */ };
+ 0 /* field_decode */,
+ 0 /* field_set_to_one */ };
return &ret;
}
+/* Most method functions in this file are designed to work with
+ * non-trivial representations of field elements if necessary
+ * (see ecp_mont.c): while standard modular addition and subtraction
+ * are used, the field_mul and field_sqr methods will be used for
+ * multiplication, and field_encode and field_decode (if defined)
+ * will be used for converting between representations.
+
+ * Functions ec_GFp_simple_points_make_affine() and
+ * ec_GFp_simple_point_get_affine_coordinates() specifically assume
+ * that if a non-trivial representation is used, it is a Montgomery
+ * representation (i.e. 'encoding' means multiplying by some factor R).
+ */
+
+
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;
}
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);
}
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);
}
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,
+int ec_GFp_simple_group_set_curve(EC_GROUP *group,
const BIGNUM *p, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
{
int ret = 0;
/* 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);
+ ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE, EC_R_INVALID_FIELD);
return 0;
}
/* group->field */
if (!BN_copy(&group->field, p)) goto err;
- group->field.neg = 0;
+ BN_set_negative(&group->field, 0);
/* group->a */
if (!BN_nnmod(tmp_a, a, p, ctx)) goto err;
}
-int ec_GFp_simple_group_get_curve_GFp(EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
+int ec_GFp_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a, BIGNUM *b, BN_CTX *ctx)
{
int ret = 0;
BN_CTX *new_ctx = NULL;
}
+int ec_GFp_simple_group_get_degree(const EC_GROUP *group)
+ {
+ return BN_num_bits(&group->field);
+ }
+
-int ec_GFp_simple_group_set_generator(EC_GROUP *group, const EC_POINT *generator,
- const BIGNUM *order, const BIGNUM *cofactor)
+int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
{
- if (generator)
+ int ret = 0;
+ BIGNUM *a,*b,*order,*tmp_1,*tmp_2;
+ const BIGNUM *p = &group->field;
+ BN_CTX *new_ctx = NULL;
+
+ if (ctx == NULL)
{
- ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_GENERATOR, ERR_R_PASSED_NULL_PARAMETER);
- return 0 ;
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
}
+ BN_CTX_start(ctx);
+ a = BN_CTX_get(ctx);
+ b = BN_CTX_get(ctx);
+ tmp_1 = BN_CTX_get(ctx);
+ tmp_2 = BN_CTX_get(ctx);
+ order = BN_CTX_get(ctx);
+ if (order == NULL) goto err;
- if (group->generator == NULL)
+ if (group->meth->field_decode)
{
- group->generator = EC_POINT_new(group);
- if (group->generator == NULL) return 0;
+ if (!group->meth->field_decode(group, a, &group->a, ctx)) goto err;
+ if (!group->meth->field_decode(group, b, &group->b, ctx)) goto err;
}
- 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);
- }
+ {
+ if (!BN_copy(a, &group->a)) goto err;
+ if (!BN_copy(b, &group->b)) goto err;
+ }
+
+ /* check the discriminant:
+ * y^2 = x^3 + a*x + b is an elliptic curve <=> 4*a^3 + 27*b^2 != 0 (mod p)
+ * 0 =< a, b < p */
+ if (BN_is_zero(a))
+ {
+ if (BN_is_zero(b)) goto err;
+ }
+ else if (!BN_is_zero(b))
+ {
+ if (!BN_mod_sqr(tmp_1, a, p, ctx)) goto err;
+ if (!BN_mod_mul(tmp_2, tmp_1, a, p, ctx)) goto err;
+ if (!BN_lshift(tmp_1, tmp_2, 2)) goto err;
+ /* tmp_1 = 4*a^3 */
+ if (!BN_mod_sqr(tmp_2, b, p, ctx)) goto err;
+ if (!BN_mul_word(tmp_2, 27)) goto err;
+ /* tmp_2 = 27*b^2 */
-int ec_GFp_simple_group_get_cofactor(EC_GROUP *group, BIGNUM *cofactor, BN_CTX *ctx)
- {
- if (!BN_copy(cofactor, &group->cofactor))
- return 0;
+ if (!BN_mod_add(a, tmp_1, tmp_2, p, ctx)) goto err;
+ if (BN_is_zero(a)) goto err;
+ }
+ ret = 1;
- return !BN_is_zero(&group->cofactor);
+err:
+ if (ctx != NULL)
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ return ret;
}
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));
+ BN_zero(&point->Z);
+ return 1;
}
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;
+ if (Z_is_one && (group->meth->field_set_to_one != 0))
+ {
+ if (!group->meth->field_set_to_one(group, &point->Z, ctx)) goto err;
+ }
+ else
+ {
+ if (!group->meth->field_encode(group, &point->Z, &point->Z, ctx)) goto err;
+ }
}
point->Z_is_one = Z_is_one;
}
}
-int ec_GFp_simple_point_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *point,
+int ec_GFp_simple_point_set_affine_coordinates(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);
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT_SET_AFFINE_COORDINATES, ERR_R_PASSED_NULL_PARAMETER);
return 0;
}
}
-int ec_GFp_simple_point_get_affine_coordinates_GFp(const EC_GROUP *group, const EC_POINT *point,
+int ec_GFp_simple_point_get_affine_coordinates(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_;
+ BIGNUM *Z, *Z_1, *Z_2, *Z_3;
+ const BIGNUM *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);
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES, EC_R_POINT_AT_INFINITY);
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);
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;
+ 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;
+ 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;
+ }
}
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)
+ if (x != NULL)
{
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
- return 0;
+ if (!BN_copy(x, &point->X)) goto err;
+ }
+ if (y != NULL)
+ {
+ if (!BN_copy(y, &point->Y)) goto err;
}
- 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)
+ else
{
- if (len < ret)
+ if (!BN_mod_inverse(Z_1, Z_, &group->field, ctx))
{
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
+ ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES, ERR_R_BN_LIB);
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)
+ if (group->meth->field_encode == 0)
{
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
+ /* field_sqr works on standard representation */
+ if (!group->meth->field_sqr(group, Z_2, Z_1, ctx)) goto err;
}
- while (skip > 0)
+ else
{
- buf[i++] = 0;
- skip--;
+ if (!BN_mod_sqr(Z_2, Z_1, &group->field, ctx)) goto err;
}
- skip = BN_bn2bin(x, buf + i);
- i += skip;
- if (i != 1 + field_len)
+
+ if (x != NULL)
{
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
+ /* in the Montgomery case, field_mul will cancel out Montgomery factor in X: */
+ if (!group->meth->field_mul(group, x, &point->X, Z_2, ctx)) goto err;
}
- if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
+ if (y != NULL)
{
- skip = field_len - BN_num_bytes(y);
- if (skip > field_len)
+ if (group->meth->field_encode == 0)
{
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
+ /* field_mul works on standard representation */
+ if (!group->meth->field_mul(group, Z_3, Z_2, Z_1, ctx)) goto err;
}
- while (skip > 0)
+ else
{
- buf[i++] = 0;
- skip--;
+ if (!BN_mod_mul(Z_3, Z_2, Z_1, &group->field, ctx)) goto err;
}
- skip = BN_bn2bin(y, buf + i);
- i += skip;
- }
- if (i != ret)
- {
- ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
- goto err;
+ /* in the Montgomery case, field_mul will cancel out Montgomery factor in Y: */
+ if (!group->meth->field_mul(group, y, &point->Y, Z_3, ctx)) 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)
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 *);
else
{
/* a is the inverse of b */
- if (!BN_zero(&r->Z)) goto end;
+ BN_zero(&r->Z);
r->Z_is_one = 0;
ret = 1;
goto end;
if (EC_POINT_is_at_infinity(group, a))
{
- if (!BN_zero(&r->Z)) return 0;
+ BN_zero(&r->Z);
r->Z_is_one = 0;
return 1;
}
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;
+ BIGNUM *rh, *tmp, *Z4, *Z6;
int ret = -1;
if (EC_POINT_is_at_infinity(group, point))
BN_CTX_start(ctx);
rh = BN_CTX_get(ctx);
- tmp1 = BN_CTX_get(ctx);
- tmp2 = BN_CTX_get(ctx);
+ tmp = BN_CTX_get(ctx);
Z4 = BN_CTX_get(ctx);
Z6 = BN_CTX_get(ctx);
if (Z6 == NULL) goto err;
* To test this, we add up the right-hand side in 'rh'.
*/
- /* rh := X^3 */
+ /* rh := X^2 */
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;
+ if (!field_sqr(group, tmp, &point->Z, ctx)) goto err;
+ if (!field_sqr(group, Z4, tmp, ctx)) goto err;
+ if (!field_mul(group, Z6, Z4, tmp, ctx)) goto err;
- /* rh := rh + a*X*Z^4 */
- if (!field_mul(group, tmp1, &point->X, Z4, ctx)) goto err;
+ /* rh := (rh + a*Z^4)*X */
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;
+ if (!BN_mod_lshift1_quick(tmp, Z4, p)) goto err;
+ if (!BN_mod_add_quick(tmp, tmp, Z4, p)) goto err;
+ if (!BN_mod_sub_quick(rh, rh, tmp, p)) goto err;
+ if (!field_mul(group, rh, rh, &point->X, ctx)) 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;
+ if (!field_mul(group, tmp, Z4, &group->a, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp, p)) goto err;
+ if (!field_mul(group, rh, rh, &point->X, ctx)) 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;
+ if (!field_mul(group, tmp, &group->b, Z6, ctx)) goto err;
+ if (!BN_mod_add_quick(rh, rh, tmp, 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 + a)*X */
+ if (!BN_mod_add_quick(rh, rh, &group->a, p)) goto err;
+ if (!field_mul(group, rh, rh, &point->X, ctx)) 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;
+ if (!field_sqr(group, tmp, &point->Y, ctx)) goto err;
- ret = (0 == BN_cmp(tmp1, rh));
+ ret = (0 == BN_ucmp(tmp, rh));
err:
BN_CTX_end(ctx);
{
return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
}
+
+ if (EC_POINT_is_at_infinity(group, b))
+ return 1;
if (a->Z_is_one && 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 */
}
- /* tmp1_ and tmp2_ are still ok */
+ else
+ tmp2_ = &b->Y;
/* compare Y_a*Z_b^3 with Y_b*Z_a^3 */
if (BN_cmp(tmp1_, tmp2_) != 0)
}
+int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
+ {
+ BN_CTX *new_ctx = NULL;
+ BIGNUM *tmp, *tmp_Z;
+ BIGNUM **prod_Z = NULL;
+ size_t i;
+ int ret = 0;
+
+ if (num == 0)
+ return 1;
+
+ if (ctx == NULL)
+ {
+ ctx = new_ctx = BN_CTX_new();
+ if (ctx == NULL)
+ return 0;
+ }
+
+ BN_CTX_start(ctx);
+ tmp = BN_CTX_get(ctx);
+ tmp_Z = BN_CTX_get(ctx);
+ if (tmp == NULL || tmp_Z == NULL) goto err;
+
+ prod_Z = OPENSSL_malloc(num * sizeof prod_Z[0]);
+ if (prod_Z == NULL) goto err;
+ for (i = 0; i < num; i++)
+ {
+ prod_Z[i] = BN_new();
+ if (prod_Z[i] == NULL) goto err;
+ }
+
+ /* Set each prod_Z[i] to the product of points[0]->Z .. points[i]->Z,
+ * skipping any zero-valued inputs (pretend that they're 1). */
+
+ if (!BN_is_zero(&points[0]->Z))
+ {
+ if (!BN_copy(prod_Z[0], &points[0]->Z)) goto err;
+ }
+ else
+ {
+ if (group->meth->field_set_to_one != 0)
+ {
+ if (!group->meth->field_set_to_one(group, prod_Z[0], ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_one(prod_Z[0])) goto err;
+ }
+ }
+
+ for (i = 1; i < num; i++)
+ {
+ if (!BN_is_zero(&points[i]->Z))
+ {
+ if (!group->meth->field_mul(group, prod_Z[i], prod_Z[i - 1], &points[i]->Z, ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_copy(prod_Z[i], prod_Z[i - 1])) goto err;
+ }
+ }
+
+ /* Now use a single explicit inversion to replace every
+ * non-zero points[i]->Z by its inverse. */
+
+ if (!BN_mod_inverse(tmp, prod_Z[num - 1], &group->field, ctx))
+ {
+ ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
+ goto err;
+ }
+ if (group->meth->field_encode != 0)
+ {
+ /* In the Montgomery case, we just turned R*H (representing H)
+ * into 1/(R*H), but we need R*(1/H) (representing 1/H);
+ * i.e. we need to multiply by the Montgomery factor twice. */
+ if (!group->meth->field_encode(group, tmp, tmp, ctx)) goto err;
+ if (!group->meth->field_encode(group, tmp, tmp, ctx)) goto err;
+ }
+
+ for (i = num - 1; i > 0; --i)
+ {
+ /* Loop invariant: tmp is the product of the inverses of
+ * points[0]->Z .. points[i]->Z (zero-valued inputs skipped). */
+ if (!BN_is_zero(&points[i]->Z))
+ {
+ /* Set tmp_Z to the inverse of points[i]->Z (as product
+ * of Z inverses 0 .. i, Z values 0 .. i - 1). */
+ if (!group->meth->field_mul(group, tmp_Z, prod_Z[i - 1], tmp, ctx)) goto err;
+ /* Update tmp to satisfy the loop invariant for i - 1. */
+ if (!group->meth->field_mul(group, tmp, tmp, &points[i]->Z, ctx)) goto err;
+ /* Replace points[i]->Z by its inverse. */
+ if (!BN_copy(&points[i]->Z, tmp_Z)) goto err;
+ }
+ }
+
+ if (!BN_is_zero(&points[0]->Z))
+ {
+ /* Replace points[0]->Z by its inverse. */
+ if (!BN_copy(&points[0]->Z, tmp)) goto err;
+ }
+
+ /* Finally, fix up the X and Y coordinates for all points. */
+
+ for (i = 0; i < num; i++)
+ {
+ EC_POINT *p = points[i];
+
+ if (!BN_is_zero(&p->Z))
+ {
+ /* turn (X, Y, 1/Z) into (X/Z^2, Y/Z^3, 1) */
+
+ if (!group->meth->field_sqr(group, tmp, &p->Z, ctx)) goto err;
+ if (!group->meth->field_mul(group, &p->X, &p->X, tmp, ctx)) goto err;
+
+ if (!group->meth->field_mul(group, tmp, tmp, &p->Z, ctx)) goto err;
+ if (!group->meth->field_mul(group, &p->Y, &p->Y, tmp, ctx)) goto err;
+
+ if (group->meth->field_set_to_one != 0)
+ {
+ if (!group->meth->field_set_to_one(group, &p->Z, ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_one(&p->Z)) goto err;
+ }
+ p->Z_is_one = 1;
+ }
+ }
+
+ ret = 1;
+
+ err:
+ BN_CTX_end(ctx);
+ if (new_ctx != NULL)
+ BN_CTX_free(new_ctx);
+ if (prod_Z != NULL)
+ {
+ for (i = 0; i < num; i++)
+ {
+ if (prod_Z[i] == NULL) break;
+ BN_clear_free(prod_Z[i]);
+ }
+ OPENSSL_free(prod_Z);
+ }
+ 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);
projects / openssl.git / blobdiff