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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifdef FREEBL_NO_DEPEND
#include "../stubs.h"
#endif
#include "mpi.h"
#include "mplogic.h"
#include "ecl.h"
#include "ecl-priv.h"
#include "ecp.h"
#include "ecl-curve.h"
#include <stdlib.h>
#include <string.h>
/* Allocate memory for a new ECGroup object. */
ECGroup *
ECGroup_new()
{
mp_err res = MP_OKAY;
ECGroup *group;
group = (ECGroup *)malloc(sizeof(ECGroup));
if (group == NULL)
return NULL;
group->constructed = MP_YES;
group->meth = NULL;
group->text = NULL;
MP_DIGITS(&group->curvea) = 0;
MP_DIGITS(&group->curveb) = 0;
MP_DIGITS(&group->genx) = 0;
MP_DIGITS(&group->geny) = 0;
MP_DIGITS(&group->order) = 0;
group->base_point_mul = NULL;
group->points_mul = NULL;
group->validate_point = NULL;
group->extra1 = NULL;
group->extra2 = NULL;
group->extra_free = NULL;
MP_CHECKOK(mp_init(&group->curvea));
MP_CHECKOK(mp_init(&group->curveb));
MP_CHECKOK(mp_init(&group->genx));
MP_CHECKOK(mp_init(&group->geny));
MP_CHECKOK(mp_init(&group->order));
CLEANUP:
if (res != MP_OKAY) {
ECGroup_free(group);
return NULL;
}
return group;
}
/* Construct a generic ECGroup for elliptic curves over prime fields. */
ECGroup *
ECGroup_consGFp(const mp_int *irr, const mp_int *curvea,
const mp_int *curveb, const mp_int *genx,
const mp_int *geny, const mp_int *order, int cofactor)
{
mp_err res = MP_OKAY;
ECGroup *group = NULL;
group = ECGroup_new();
if (group == NULL)
return NULL;
group->meth = GFMethod_consGFp(irr);
if (group->meth == NULL) {
res = MP_MEM;
goto CLEANUP;
}
MP_CHECKOK(mp_copy(curvea, &group->curvea));
MP_CHECKOK(mp_copy(curveb, &group->curveb));
MP_CHECKOK(mp_copy(genx, &group->genx));
MP_CHECKOK(mp_copy(geny, &group->geny));
MP_CHECKOK(mp_copy(order, &group->order));
group->cofactor = cofactor;
group->point_add = &ec_GFp_pt_add_aff;
group->point_sub = &ec_GFp_pt_sub_aff;
group->point_dbl = &ec_GFp_pt_dbl_aff;
group->point_mul = &ec_GFp_pt_mul_jm_wNAF;
group->base_point_mul = NULL;
group->points_mul = &ec_GFp_pts_mul_jac;
group->validate_point = &ec_GFp_validate_point;
CLEANUP:
if (res != MP_OKAY) {
ECGroup_free(group);
return NULL;
}
return group;
}
/* Construct a generic ECGroup for elliptic curves over prime fields with
* field arithmetic implemented in Montgomery coordinates. */
ECGroup *
ECGroup_consGFp_mont(const mp_int *irr, const mp_int *curvea,
const mp_int *curveb, const mp_int *genx,
const mp_int *geny, const mp_int *order, int cofactor)
{
mp_err res = MP_OKAY;
ECGroup *group = NULL;
group = ECGroup_new();
if (group == NULL)
return NULL;
group->meth = GFMethod_consGFp_mont(irr);
if (group->meth == NULL) {
res = MP_MEM;
goto CLEANUP;
}
MP_CHECKOK(group->meth->field_enc(curvea, &group->curvea, group->meth));
MP_CHECKOK(group->meth->field_enc(curveb, &group->curveb, group->meth));
MP_CHECKOK(group->meth->field_enc(genx, &group->genx, group->meth));
MP_CHECKOK(group->meth->field_enc(geny, &group->geny, group->meth));
MP_CHECKOK(mp_copy(order, &group->order));
group->cofactor = cofactor;
group->point_add = &ec_GFp_pt_add_aff;
group->point_sub = &ec_GFp_pt_sub_aff;
group->point_dbl = &ec_GFp_pt_dbl_aff;
group->point_mul = &ec_GFp_pt_mul_jm_wNAF;
group->base_point_mul = NULL;
group->points_mul = &ec_GFp_pts_mul_jac;
group->validate_point = &ec_GFp_validate_point;
CLEANUP:
if (res != MP_OKAY) {
ECGroup_free(group);
return NULL;
}
return group;
}
/* Construct an ECGroup. */
ECGroup *
construct_ecgroup(const ECCurveName name, mp_int irr, mp_int curvea,
mp_int curveb, mp_int genx, mp_int geny, mp_int order,
int cofactor, ECField field, const char *text)
{
int bits;
ECGroup *group = NULL;
mp_err res = MP_OKAY;
/* determine number of bits */
bits = mpl_significant_bits(&irr) - 1;
if (bits < MP_OKAY) {
res = bits;
goto CLEANUP;
}
/* determine which optimizations (if any) to use */
if (field == ECField_GFp) {
switch (name) {
case ECCurve_SECG_PRIME_256R1:
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_gfp256(group, name));
MP_CHECKOK(ec_group_set_gfp256_32(group, name));
break;
case ECCurve_SECG_PRIME_521R1:
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_gfp521(group, name));
break;
default:
/* use generic arithmetic */
group =
ECGroup_consGFp_mont(&irr, &curvea, &curveb, &genx, &geny,
&order, cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
}
} else {
res = MP_UNDEF;
goto CLEANUP;
}
/* set name, if any */
if ((group != NULL) && (text != NULL)) {
group->text = strdup(text);
if (group->text == NULL) {
res = MP_MEM;
}
}
CLEANUP:
if (group && res != MP_OKAY) {
ECGroup_free(group);
return NULL;
}
return group;
}
/* Construct ECGroup from parameters and name, if any. */
ECGroup *
ecgroup_fromName(const ECCurveName name,
const ECCurveBytes *params)
{
mp_int irr, curvea, curveb, genx, geny, order;
ECGroup *group = NULL;
mp_err res = MP_OKAY;
/* initialize values */
MP_DIGITS(&irr) = 0;
MP_DIGITS(&curvea) = 0;
MP_DIGITS(&curveb) = 0;
MP_DIGITS(&genx) = 0;
MP_DIGITS(&geny) = 0;
MP_DIGITS(&order) = 0;
MP_CHECKOK(mp_init(&irr));
MP_CHECKOK(mp_init(&curvea));
MP_CHECKOK(mp_init(&curveb));
MP_CHECKOK(mp_init(&genx));
MP_CHECKOK(mp_init(&geny));
MP_CHECKOK(mp_init(&order));
MP_CHECKOK(mp_read_unsigned_octets(&irr, params->irr, params->scalarSize));
MP_CHECKOK(mp_read_unsigned_octets(&curvea, params->curvea, params->scalarSize));
MP_CHECKOK(mp_read_unsigned_octets(&curveb, params->curveb, params->scalarSize));
MP_CHECKOK(mp_read_unsigned_octets(&genx, params->genx, params->scalarSize));
MP_CHECKOK(mp_read_unsigned_octets(&geny, params->geny, params->scalarSize));
MP_CHECKOK(mp_read_unsigned_octets(&order, params->order, params->scalarSize));
group = construct_ecgroup(name, irr, curvea, curveb, genx, geny, order,
params->cofactor, params->field, params->text);
CLEANUP:
mp_clear(&irr);
mp_clear(&curvea);
mp_clear(&curveb);
mp_clear(&genx);
mp_clear(&geny);
mp_clear(&order);
if (group && res != MP_OKAY) {
ECGroup_free(group);
return NULL;
}
return group;
}
/* Construct ECCurveBytes from an ECCurveName */
const ECCurveBytes *
ec_GetNamedCurveParams(const ECCurveName name)
{
if ((name <= ECCurve_noName) || (ECCurve_pastLastCurve <= name) ||
(ecCurve_map[name] == NULL)) {
return NULL;
} else {
return ecCurve_map[name];
}
}
/* Construct ECGroup from named parameters. */
ECGroup *
ECGroup_fromName(const ECCurveName name)
{
const ECCurveBytes *params = NULL;
/* This doesn't work with Curve25519 but it's not necessary to. */
PORT_Assert(name != ECCurve25519);
params = ec_GetNamedCurveParams(name);
if (params == NULL) {
return NULL;
}
/* construct actual group */
return ecgroup_fromName(name, params);
}
/* Validates an EC public key as described in Section 5.2.2 of X9.62. */
mp_err
ECPoint_validate(const ECGroup *group, const mp_int *px, const mp_int *py)
{
/* 1: Verify that publicValue is not the point at infinity */
/* 2: Verify that the coordinates of publicValue are elements
* of the field.
*/
/* 3: Verify that publicValue is on the curve. */
/* 4: Verify that the order of the curve times the publicValue
* is the point at infinity.
*/
return group->validate_point(px, py, group);
}
/* Free the memory allocated (if any) to an ECGroup object. */
void
ECGroup_free(ECGroup *group)
{
if (group == NULL)
return;
GFMethod_free(group->meth);
if (group->constructed == MP_NO)
return;
mp_clear(&group->curvea);
mp_clear(&group->curveb);
mp_clear(&group->genx);
mp_clear(&group->geny);
mp_clear(&group->order);
if (group->text != NULL)
free(group->text);
if (group->extra_free != NULL)
group->extra_free(group);
free(group);
}
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