/*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the elliptic curve math library for prime field curves.
*
* The Initial Developer of the Original Code is
* Sun Microsystems, Inc.
* Portions created by the Initial Developer are Copyright (C) 2003
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Douglas Stebila <douglas@stebila.ca>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*
* Sun elects to use this software under the MPL license.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include "ecp.h"
#include "mpi.h"
#include "mplogic.h"
#include "mpi-priv.h"
#ifndef _KERNEL
#include <stdlib.h>
#endif
/* Fast modular reduction for p256 = 2^256 - 2^224 + 2^192+ 2^96 - 1. a can be r.
* Uses algorithm 2.29 from Hankerson, Menezes, Vanstone. Guide to
* Elliptic Curve Cryptography. */
{
#ifdef ECL_THIRTY_TWO_BIT
#else
#endif
/* for polynomials larger than twice the field size
* use regular reduction */
if (a_bits < 256) {
if (a == r) return MP_OKAY;
return mp_copy(a,r);
}
if (a_bits > 512) {
} else {
#ifdef ECL_THIRTY_TWO_BIT
switch (a_used) {
case 16:
case 15:
case 14:
case 13:
case 12:
case 11:
case 10:
case 9:
}
/* sum 1 */
/* sum 2 */
/* combine last bottom of sum 3 with second sum 2 */
/* sum 3 (rest of it)*/
/* sum 4 (rest of it)*/
/* diff 5 */
/* diff 6 */
/* diff 7 */
/* diff 8 */
/* reduce the overflows */
while (r8 > 0) {
}
/* reduce the underflows */
while (r8 < 0) {
}
if (a != r) {
}
MP_USED(r) = 8;
/* final reduction if necessary */
if ((r7 == MP_DIGIT_MAX) &&
&& (r0 == MP_DIGIT_MAX)))))) {
}
#ifdef notdef
/* smooth the negatives */
}
while (MP_USED(r) > 8) {
}
/* final reduction if necessary */
}
}
#endif
s_mp_clamp(r);
#else
switch (a_used) {
case 8:
case 7:
case 6:
case 5:
}
/* sum 1 */
/* sum 2 */
/* sum 3 */
/* sum 4 */
/* diff 5 */
/* diff 6 */
/* diff 7 */
/* diff 8 */
/* reduce the overflows */
while (r4 > 0) {
}
/* reduce the underflows */
while (r4 < 0) {
}
if (a != r) {
}
MP_USED(r) = 4;
/* final reduction if necessary */
if ((r3 > 0xFFFFFFFF00000001ULL) ||
((r3 == 0xFFFFFFFF00000001ULL) &&
/* very rare, just use mp_sub */
}
s_mp_clamp(r);
#endif
}
return res;
}
/* Compute the square of polynomial a, reduce modulo p256. Store the
* result in r. r could be a. Uses optimized modular reduction for p256.
*/
{
MP_CHECKOK(mp_sqr(a, r));
return res;
}
/* Compute the product of two polynomials a and b, reduce modulo p256.
* Store the result in r. r could be a or b; a could be b. Uses
* optimized modular reduction for p256. */
{
MP_CHECKOK(mp_mul(a, b, r));
return res;
}
/* Wire in fast field arithmetic and precomputation of base point for
* named curves. */
{
if (name == ECCurve_NIST_P256) {
}
return MP_OKAY;
}