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554 lines
18 KiB
C
554 lines
18 KiB
C
/*
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is the elliptic curve math library for prime field curves.
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*
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* The Initial Developer of the Original Code is
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* Sun Microsystems, Inc.
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* Portions created by the Initial Developer are Copyright (C) 2003
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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* Sheueling Chang-Shantz <sheueling.chang@sun.com>,
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* Stephen Fung <fungstep@hotmail.com>, and
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* Douglas Stebila <douglas@stebila.ca>, Sun Microsystems Laboratories.
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* Bodo Moeller <moeller@cdc.informatik.tu-darmstadt.de>,
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* Nils Larsch <nla@trustcenter.de>, and
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* Lenka Fibikova <fibikova@exp-math.uni-essen.de>, the OpenSSL Project
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either the GNU General Public License Version 2 or later (the "GPL"), or
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* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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#include "ecp.h"
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#include "mplogic.h"
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#include <stdlib.h>
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#ifdef ECL_DEBUG
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#include <assert.h>
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#endif
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/* Converts a point P(px, py) from affine coordinates to Jacobian
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* projective coordinates R(rx, ry, rz). Assumes input is already
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* field-encoded using field_enc, and returns output that is still
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* field-encoded. */
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mp_err
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ec_GFp_pt_aff2jac(const mp_int *px, const mp_int *py, mp_int *rx,
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mp_int *ry, mp_int *rz, const ECGroup *group)
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{
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mp_err res = MP_OKAY;
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if (ec_GFp_pt_is_inf_aff(px, py) == MP_YES) {
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MP_CHECKOK(ec_GFp_pt_set_inf_jac(rx, ry, rz));
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} else {
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MP_CHECKOK(mp_copy(px, rx));
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MP_CHECKOK(mp_copy(py, ry));
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MP_CHECKOK(mp_set_int(rz, 1));
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if (group->meth->field_enc) {
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MP_CHECKOK(group->meth->field_enc(rz, rz, group->meth));
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}
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}
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CLEANUP:
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return res;
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}
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/* Converts a point P(px, py, pz) from Jacobian projective coordinates to
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* affine coordinates R(rx, ry). P and R can share x and y coordinates.
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* Assumes input is already field-encoded using field_enc, and returns
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* output that is still field-encoded. */
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mp_err
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ec_GFp_pt_jac2aff(const mp_int *px, const mp_int *py, const mp_int *pz,
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mp_int *rx, mp_int *ry, const ECGroup *group)
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{
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mp_err res = MP_OKAY;
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mp_int z1, z2, z3;
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MP_DIGITS(&z1) = 0;
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MP_DIGITS(&z2) = 0;
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MP_DIGITS(&z3) = 0;
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MP_CHECKOK(mp_init(&z1));
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MP_CHECKOK(mp_init(&z2));
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MP_CHECKOK(mp_init(&z3));
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/* if point at infinity, then set point at infinity and exit */
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if (ec_GFp_pt_is_inf_jac(px, py, pz) == MP_YES) {
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MP_CHECKOK(ec_GFp_pt_set_inf_aff(rx, ry));
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goto CLEANUP;
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}
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/* transform (px, py, pz) into (px / pz^2, py / pz^3) */
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if (mp_cmp_d(pz, 1) == 0) {
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MP_CHECKOK(mp_copy(px, rx));
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MP_CHECKOK(mp_copy(py, ry));
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} else {
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MP_CHECKOK(group->meth->field_div(NULL, pz, &z1, group->meth));
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MP_CHECKOK(group->meth->field_sqr(&z1, &z2, group->meth));
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MP_CHECKOK(group->meth->field_mul(&z1, &z2, &z3, group->meth));
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MP_CHECKOK(group->meth->field_mul(px, &z2, rx, group->meth));
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MP_CHECKOK(group->meth->field_mul(py, &z3, ry, group->meth));
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}
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CLEANUP:
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mp_clear(&z1);
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mp_clear(&z2);
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mp_clear(&z3);
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return res;
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}
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/* Checks if point P(px, py, pz) is at infinity. Uses Jacobian
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* coordinates. */
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mp_err
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ec_GFp_pt_is_inf_jac(const mp_int *px, const mp_int *py, const mp_int *pz)
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{
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return mp_cmp_z(pz);
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}
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/* Sets P(px, py, pz) to be the point at infinity. Uses Jacobian
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* coordinates. */
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mp_err
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ec_GFp_pt_set_inf_jac(mp_int *px, mp_int *py, mp_int *pz)
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{
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mp_zero(pz);
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return MP_OKAY;
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}
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/* Computes R = P + Q where R is (rx, ry, rz), P is (px, py, pz) and Q is
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* (qx, qy, 1). Elliptic curve points P, Q, and R can all be identical.
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* Uses mixed Jacobian-affine coordinates. Assumes input is already
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* field-encoded using field_enc, and returns output that is still
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* field-encoded. Uses equation (2) from Brown, Hankerson, Lopez, and
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* Menezes. Software Implementation of the NIST Elliptic Curves Over Prime
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* Fields. */
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mp_err
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ec_GFp_pt_add_jac_aff(const mp_int *px, const mp_int *py, const mp_int *pz,
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const mp_int *qx, const mp_int *qy, mp_int *rx,
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mp_int *ry, mp_int *rz, const ECGroup *group)
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{
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mp_err res = MP_OKAY;
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mp_int A, B, C, D, C2, C3;
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MP_DIGITS(&A) = 0;
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MP_DIGITS(&B) = 0;
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MP_DIGITS(&C) = 0;
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MP_DIGITS(&D) = 0;
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MP_DIGITS(&C2) = 0;
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MP_DIGITS(&C3) = 0;
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MP_CHECKOK(mp_init(&A));
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MP_CHECKOK(mp_init(&B));
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MP_CHECKOK(mp_init(&C));
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MP_CHECKOK(mp_init(&D));
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MP_CHECKOK(mp_init(&C2));
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MP_CHECKOK(mp_init(&C3));
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/* If either P or Q is the point at infinity, then return the other
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* point */
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if (ec_GFp_pt_is_inf_jac(px, py, pz) == MP_YES) {
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MP_CHECKOK(ec_GFp_pt_aff2jac(qx, qy, rx, ry, rz, group));
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goto CLEANUP;
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}
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if (ec_GFp_pt_is_inf_aff(qx, qy) == MP_YES) {
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MP_CHECKOK(mp_copy(px, rx));
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MP_CHECKOK(mp_copy(py, ry));
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MP_CHECKOK(mp_copy(pz, rz));
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goto CLEANUP;
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}
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/* A = qx * pz^2, B = qy * pz^3 */
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MP_CHECKOK(group->meth->field_sqr(pz, &A, group->meth));
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MP_CHECKOK(group->meth->field_mul(&A, pz, &B, group->meth));
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MP_CHECKOK(group->meth->field_mul(&A, qx, &A, group->meth));
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MP_CHECKOK(group->meth->field_mul(&B, qy, &B, group->meth));
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/* C = A - px, D = B - py */
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MP_CHECKOK(group->meth->field_sub(&A, px, &C, group->meth));
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MP_CHECKOK(group->meth->field_sub(&B, py, &D, group->meth));
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/* C2 = C^2, C3 = C^3 */
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MP_CHECKOK(group->meth->field_sqr(&C, &C2, group->meth));
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MP_CHECKOK(group->meth->field_mul(&C, &C2, &C3, group->meth));
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/* rz = pz * C */
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MP_CHECKOK(group->meth->field_mul(pz, &C, rz, group->meth));
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/* C = px * C^2 */
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MP_CHECKOK(group->meth->field_mul(px, &C2, &C, group->meth));
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/* A = D^2 */
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MP_CHECKOK(group->meth->field_sqr(&D, &A, group->meth));
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/* rx = D^2 - (C^3 + 2 * (px * C^2)) */
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MP_CHECKOK(group->meth->field_add(&C, &C, rx, group->meth));
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MP_CHECKOK(group->meth->field_add(&C3, rx, rx, group->meth));
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MP_CHECKOK(group->meth->field_sub(&A, rx, rx, group->meth));
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/* C3 = py * C^3 */
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MP_CHECKOK(group->meth->field_mul(py, &C3, &C3, group->meth));
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/* ry = D * (px * C^2 - rx) - py * C^3 */
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MP_CHECKOK(group->meth->field_sub(&C, rx, ry, group->meth));
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MP_CHECKOK(group->meth->field_mul(&D, ry, ry, group->meth));
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MP_CHECKOK(group->meth->field_sub(ry, &C3, ry, group->meth));
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CLEANUP:
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mp_clear(&A);
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mp_clear(&B);
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mp_clear(&C);
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mp_clear(&D);
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mp_clear(&C2);
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mp_clear(&C3);
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return res;
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}
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/* Computes R = 2P. Elliptic curve points P and R can be identical. Uses
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* Jacobian coordinates.
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*
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* Assumes input is already field-encoded using field_enc, and returns
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* output that is still field-encoded.
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*
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* This routine implements Point Doubling in the Jacobian Projective
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* space as described in the paper "Efficient elliptic curve exponentiation
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* using mixed coordinates", by H. Cohen, A Miyaji, T. Ono.
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*/
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mp_err
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ec_GFp_pt_dbl_jac(const mp_int *px, const mp_int *py, const mp_int *pz,
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mp_int *rx, mp_int *ry, mp_int *rz, const ECGroup *group)
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{
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mp_err res = MP_OKAY;
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mp_int t0, t1, M, S;
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MP_DIGITS(&t0) = 0;
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MP_DIGITS(&t1) = 0;
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MP_DIGITS(&M) = 0;
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MP_DIGITS(&S) = 0;
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MP_CHECKOK(mp_init(&t0));
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MP_CHECKOK(mp_init(&t1));
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MP_CHECKOK(mp_init(&M));
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MP_CHECKOK(mp_init(&S));
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if (ec_GFp_pt_is_inf_jac(px, py, pz) == MP_YES) {
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MP_CHECKOK(ec_GFp_pt_set_inf_jac(rx, ry, rz));
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goto CLEANUP;
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}
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if (mp_cmp_d(pz, 1) == 0) {
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/* M = 3 * px^2 + a */
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MP_CHECKOK(group->meth->field_sqr(px, &t0, group->meth));
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MP_CHECKOK(group->meth->field_add(&t0, &t0, &M, group->meth));
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MP_CHECKOK(group->meth->field_add(&t0, &M, &t0, group->meth));
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MP_CHECKOK(group->meth->
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field_add(&t0, &group->curvea, &M, group->meth));
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} else if (mp_cmp_int(&group->curvea, -3) == 0) {
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/* M = 3 * (px + pz^2) * (px - pz^2) */
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MP_CHECKOK(group->meth->field_sqr(pz, &M, group->meth));
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MP_CHECKOK(group->meth->field_add(px, &M, &t0, group->meth));
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MP_CHECKOK(group->meth->field_sub(px, &M, &t1, group->meth));
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MP_CHECKOK(group->meth->field_mul(&t0, &t1, &M, group->meth));
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MP_CHECKOK(group->meth->field_add(&M, &M, &t0, group->meth));
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MP_CHECKOK(group->meth->field_add(&t0, &M, &M, group->meth));
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} else {
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/* M = 3 * (px^2) + a * (pz^4) */
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MP_CHECKOK(group->meth->field_sqr(px, &t0, group->meth));
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MP_CHECKOK(group->meth->field_add(&t0, &t0, &M, group->meth));
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MP_CHECKOK(group->meth->field_add(&t0, &M, &t0, group->meth));
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MP_CHECKOK(group->meth->field_sqr(pz, &M, group->meth));
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MP_CHECKOK(group->meth->field_sqr(&M, &M, group->meth));
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MP_CHECKOK(group->meth->
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field_mul(&M, &group->curvea, &M, group->meth));
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MP_CHECKOK(group->meth->field_add(&M, &t0, &M, group->meth));
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}
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/* rz = 2 * py * pz */
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/* t0 = 4 * py^2 */
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if (mp_cmp_d(pz, 1) == 0) {
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MP_CHECKOK(group->meth->field_add(py, py, rz, group->meth));
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MP_CHECKOK(group->meth->field_sqr(rz, &t0, group->meth));
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} else {
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MP_CHECKOK(group->meth->field_add(py, py, &t0, group->meth));
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MP_CHECKOK(group->meth->field_mul(&t0, pz, rz, group->meth));
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MP_CHECKOK(group->meth->field_sqr(&t0, &t0, group->meth));
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}
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/* S = 4 * px * py^2 = px * (2 * py)^2 */
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MP_CHECKOK(group->meth->field_mul(px, &t0, &S, group->meth));
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/* rx = M^2 - 2 * S */
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MP_CHECKOK(group->meth->field_add(&S, &S, &t1, group->meth));
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MP_CHECKOK(group->meth->field_sqr(&M, rx, group->meth));
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MP_CHECKOK(group->meth->field_sub(rx, &t1, rx, group->meth));
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/* ry = M * (S - rx) - 8 * py^4 */
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MP_CHECKOK(group->meth->field_sqr(&t0, &t1, group->meth));
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if (mp_isodd(&t1)) {
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MP_CHECKOK(mp_add(&t1, &group->meth->irr, &t1));
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}
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MP_CHECKOK(mp_div_2(&t1, &t1));
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MP_CHECKOK(group->meth->field_sub(&S, rx, &S, group->meth));
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MP_CHECKOK(group->meth->field_mul(&M, &S, &M, group->meth));
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MP_CHECKOK(group->meth->field_sub(&M, &t1, ry, group->meth));
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CLEANUP:
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mp_clear(&t0);
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mp_clear(&t1);
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mp_clear(&M);
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mp_clear(&S);
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return res;
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}
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/* by default, this routine is unused and thus doesn't need to be compiled */
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#ifdef ECL_ENABLE_GFP_PT_MUL_JAC
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/* Computes R = nP where R is (rx, ry) and P is (px, py). The parameters
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* a, b and p are the elliptic curve coefficients and the prime that
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* determines the field GFp. Elliptic curve points P and R can be
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* identical. Uses mixed Jacobian-affine coordinates. Assumes input is
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* already field-encoded using field_enc, and returns output that is still
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* field-encoded. Uses 4-bit window method. */
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mp_err
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ec_GFp_pt_mul_jac(const mp_int *n, const mp_int *px, const mp_int *py,
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mp_int *rx, mp_int *ry, const ECGroup *group)
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{
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mp_err res = MP_OKAY;
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mp_int precomp[16][2], rz;
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int i, ni, d;
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MP_DIGITS(&rz) = 0;
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for (i = 0; i < 16; i++) {
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MP_DIGITS(&precomp[i][0]) = 0;
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MP_DIGITS(&precomp[i][1]) = 0;
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}
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ARGCHK(group != NULL, MP_BADARG);
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ARGCHK((n != NULL) && (px != NULL) && (py != NULL), MP_BADARG);
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/* initialize precomputation table */
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for (i = 0; i < 16; i++) {
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MP_CHECKOK(mp_init(&precomp[i][0]));
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MP_CHECKOK(mp_init(&precomp[i][1]));
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}
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/* fill precomputation table */
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mp_zero(&precomp[0][0]);
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mp_zero(&precomp[0][1]);
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MP_CHECKOK(mp_copy(px, &precomp[1][0]));
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MP_CHECKOK(mp_copy(py, &precomp[1][1]));
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for (i = 2; i < 16; i++) {
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MP_CHECKOK(group->
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point_add(&precomp[1][0], &precomp[1][1],
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&precomp[i - 1][0], &precomp[i - 1][1],
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&precomp[i][0], &precomp[i][1], group));
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}
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d = (mpl_significant_bits(n) + 3) / 4;
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/* R = inf */
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MP_CHECKOK(mp_init(&rz));
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MP_CHECKOK(ec_GFp_pt_set_inf_jac(rx, ry, &rz));
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for (i = d - 1; i >= 0; i--) {
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/* compute window ni */
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ni = MP_GET_BIT(n, 4 * i + 3);
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ni <<= 1;
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ni |= MP_GET_BIT(n, 4 * i + 2);
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ni <<= 1;
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ni |= MP_GET_BIT(n, 4 * i + 1);
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ni <<= 1;
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ni |= MP_GET_BIT(n, 4 * i);
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/* R = 2^4 * R */
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MP_CHECKOK(ec_GFp_pt_dbl_jac(rx, ry, &rz, rx, ry, &rz, group));
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MP_CHECKOK(ec_GFp_pt_dbl_jac(rx, ry, &rz, rx, ry, &rz, group));
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MP_CHECKOK(ec_GFp_pt_dbl_jac(rx, ry, &rz, rx, ry, &rz, group));
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MP_CHECKOK(ec_GFp_pt_dbl_jac(rx, ry, &rz, rx, ry, &rz, group));
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/* R = R + (ni * P) */
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MP_CHECKOK(ec_GFp_pt_add_jac_aff
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(rx, ry, &rz, &precomp[ni][0], &precomp[ni][1], rx, ry,
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&rz, group));
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}
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/* convert result S to affine coordinates */
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MP_CHECKOK(ec_GFp_pt_jac2aff(rx, ry, &rz, rx, ry, group));
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CLEANUP:
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mp_clear(&rz);
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for (i = 0; i < 16; i++) {
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mp_clear(&precomp[i][0]);
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mp_clear(&precomp[i][1]);
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}
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return res;
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}
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#endif
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/* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G +
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* k2 * P(x, y), where G is the generator (base point) of the group of
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* points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL.
|
|
* Uses mixed Jacobian-affine coordinates. Input and output values are
|
|
* assumed to be NOT field-encoded. Uses algorithm 15 (simultaneous
|
|
* multiple point multiplication) from Brown, Hankerson, Lopez, Menezes.
|
|
* Software Implementation of the NIST Elliptic Curves over Prime Fields. */
|
|
mp_err
|
|
ec_GFp_pts_mul_jac(const mp_int *k1, const mp_int *k2, const mp_int *px,
|
|
const mp_int *py, mp_int *rx, mp_int *ry,
|
|
const ECGroup *group)
|
|
{
|
|
mp_err res = MP_OKAY;
|
|
mp_int precomp[4][4][2];
|
|
mp_int rz;
|
|
const mp_int *a, *b;
|
|
int i, j;
|
|
int ai, bi, d;
|
|
|
|
for (i = 0; i < 4; i++) {
|
|
for (j = 0; j < 4; j++) {
|
|
MP_DIGITS(&precomp[i][j][0]) = 0;
|
|
MP_DIGITS(&precomp[i][j][1]) = 0;
|
|
}
|
|
}
|
|
MP_DIGITS(&rz) = 0;
|
|
|
|
ARGCHK(group != NULL, MP_BADARG);
|
|
ARGCHK(!((k1 == NULL)
|
|
&& ((k2 == NULL) || (px == NULL)
|
|
|| (py == NULL))), MP_BADARG);
|
|
|
|
/* if some arguments are not defined used ECPoint_mul */
|
|
if (k1 == NULL) {
|
|
return ECPoint_mul(group, k2, px, py, rx, ry);
|
|
} else if ((k2 == NULL) || (px == NULL) || (py == NULL)) {
|
|
return ECPoint_mul(group, k1, NULL, NULL, rx, ry);
|
|
}
|
|
|
|
/* initialize precomputation table */
|
|
for (i = 0; i < 4; i++) {
|
|
for (j = 0; j < 4; j++) {
|
|
MP_CHECKOK(mp_init(&precomp[i][j][0]));
|
|
MP_CHECKOK(mp_init(&precomp[i][j][1]));
|
|
}
|
|
}
|
|
|
|
/* fill precomputation table */
|
|
/* assign {k1, k2} = {a, b} such that len(a) >= len(b) */
|
|
if (mpl_significant_bits(k1) < mpl_significant_bits(k2)) {
|
|
a = k2;
|
|
b = k1;
|
|
if (group->meth->field_enc) {
|
|
MP_CHECKOK(group->meth->
|
|
field_enc(px, &precomp[1][0][0], group->meth));
|
|
MP_CHECKOK(group->meth->
|
|
field_enc(py, &precomp[1][0][1], group->meth));
|
|
} else {
|
|
MP_CHECKOK(mp_copy(px, &precomp[1][0][0]));
|
|
MP_CHECKOK(mp_copy(py, &precomp[1][0][1]));
|
|
}
|
|
MP_CHECKOK(mp_copy(&group->genx, &precomp[0][1][0]));
|
|
MP_CHECKOK(mp_copy(&group->geny, &precomp[0][1][1]));
|
|
} else {
|
|
a = k1;
|
|
b = k2;
|
|
MP_CHECKOK(mp_copy(&group->genx, &precomp[1][0][0]));
|
|
MP_CHECKOK(mp_copy(&group->geny, &precomp[1][0][1]));
|
|
if (group->meth->field_enc) {
|
|
MP_CHECKOK(group->meth->
|
|
field_enc(px, &precomp[0][1][0], group->meth));
|
|
MP_CHECKOK(group->meth->
|
|
field_enc(py, &precomp[0][1][1], group->meth));
|
|
} else {
|
|
MP_CHECKOK(mp_copy(px, &precomp[0][1][0]));
|
|
MP_CHECKOK(mp_copy(py, &precomp[0][1][1]));
|
|
}
|
|
}
|
|
/* precompute [*][0][*] */
|
|
mp_zero(&precomp[0][0][0]);
|
|
mp_zero(&precomp[0][0][1]);
|
|
MP_CHECKOK(group->
|
|
point_dbl(&precomp[1][0][0], &precomp[1][0][1],
|
|
&precomp[2][0][0], &precomp[2][0][1], group));
|
|
MP_CHECKOK(group->
|
|
point_add(&precomp[1][0][0], &precomp[1][0][1],
|
|
&precomp[2][0][0], &precomp[2][0][1],
|
|
&precomp[3][0][0], &precomp[3][0][1], group));
|
|
/* precompute [*][1][*] */
|
|
for (i = 1; i < 4; i++) {
|
|
MP_CHECKOK(group->
|
|
point_add(&precomp[0][1][0], &precomp[0][1][1],
|
|
&precomp[i][0][0], &precomp[i][0][1],
|
|
&precomp[i][1][0], &precomp[i][1][1], group));
|
|
}
|
|
/* precompute [*][2][*] */
|
|
MP_CHECKOK(group->
|
|
point_dbl(&precomp[0][1][0], &precomp[0][1][1],
|
|
&precomp[0][2][0], &precomp[0][2][1], group));
|
|
for (i = 1; i < 4; i++) {
|
|
MP_CHECKOK(group->
|
|
point_add(&precomp[0][2][0], &precomp[0][2][1],
|
|
&precomp[i][0][0], &precomp[i][0][1],
|
|
&precomp[i][2][0], &precomp[i][2][1], group));
|
|
}
|
|
/* precompute [*][3][*] */
|
|
MP_CHECKOK(group->
|
|
point_add(&precomp[0][1][0], &precomp[0][1][1],
|
|
&precomp[0][2][0], &precomp[0][2][1],
|
|
&precomp[0][3][0], &precomp[0][3][1], group));
|
|
for (i = 1; i < 4; i++) {
|
|
MP_CHECKOK(group->
|
|
point_add(&precomp[0][3][0], &precomp[0][3][1],
|
|
&precomp[i][0][0], &precomp[i][0][1],
|
|
&precomp[i][3][0], &precomp[i][3][1], group));
|
|
}
|
|
|
|
d = (mpl_significant_bits(a) + 1) / 2;
|
|
|
|
/* R = inf */
|
|
MP_CHECKOK(mp_init(&rz));
|
|
MP_CHECKOK(ec_GFp_pt_set_inf_jac(rx, ry, &rz));
|
|
|
|
for (i = d - 1; i >= 0; i--) {
|
|
ai = MP_GET_BIT(a, 2 * i + 1);
|
|
ai <<= 1;
|
|
ai |= MP_GET_BIT(a, 2 * i);
|
|
bi = MP_GET_BIT(b, 2 * i + 1);
|
|
bi <<= 1;
|
|
bi |= MP_GET_BIT(b, 2 * i);
|
|
/* R = 2^2 * R */
|
|
MP_CHECKOK(ec_GFp_pt_dbl_jac(rx, ry, &rz, rx, ry, &rz, group));
|
|
MP_CHECKOK(ec_GFp_pt_dbl_jac(rx, ry, &rz, rx, ry, &rz, group));
|
|
/* R = R + (ai * A + bi * B) */
|
|
MP_CHECKOK(ec_GFp_pt_add_jac_aff
|
|
(rx, ry, &rz, &precomp[ai][bi][0], &precomp[ai][bi][1],
|
|
rx, ry, &rz, group));
|
|
}
|
|
|
|
MP_CHECKOK(ec_GFp_pt_jac2aff(rx, ry, &rz, rx, ry, group));
|
|
|
|
if (group->meth->field_dec) {
|
|
MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth));
|
|
MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth));
|
|
}
|
|
|
|
CLEANUP:
|
|
mp_clear(&rz);
|
|
for (i = 0; i < 4; i++) {
|
|
for (j = 0; j < 4; j++) {
|
|
mp_clear(&precomp[i][j][0]);
|
|
mp_clear(&precomp[i][j][1]);
|
|
}
|
|
}
|
|
return res;
|
|
}
|