/* -*-c-*-
*
- * $Id: ec-bin.c,v 1.9 2004/04/08 01:36:15 mdw Exp $
+ * $Id$
*
* Arithmetic for elliptic curves over binary fields
*
* (c) 2004 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of Catacomb.
*
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
- *
+ *
* Catacomb is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
- *
+ *
* You should have received a copy of the GNU Library General Public
* License along with Catacomb; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
#include <mLib/sub.h>
#include "ec.h"
-
-/*----- Data structures ---------------------------------------------------*/
-
-typedef struct ecctx {
- ec_curve c;
- mp *bb;
-} ecctx;
+#include "ec-guts.h"
/*----- Main code ---------------------------------------------------------*/
{
field *f = c->f;
mp *y, *u, *v;
-
+
if (F_ZEROP(f, x))
y = F_SQRT(f, MP_NEW, c->b);
else {
EC_SETINF(d);
else {
field *f = c->f;
- ecctx *cc = (ecctx *)c;
+ ecctx_bin *cc = (ecctx_bin *)c;
mp *dx, *dy, *dz, *u, *v;
dy = F_SQR(f, MP_NEW, a->z); /* %$z^2$% */
dx = F_ADD(f, dx, dx, c->a); /* %$a + \lambda^2 + \lambda$% */
dx = F_ADD(f, dx, dx, a->x); /* %$a + \lambda^2 + \lambda + x_0$% */
dx = F_ADD(f, dx, dx, b->x);
- /* %$x' = a + \lambda^2 + \lambda + x_0 + x_1$% */
+ /* %$x' = a + \lambda^2 + \lambda + x_0 + x_1$% */
} else if (!MP_EQ(a->y, b->y) || F_ZEROP(f, a->x)) {
EC_SETINF(d);
return (d);
dx = F_ADD(f, dx, dx, c->a); /* %$x' = a + \lambda^2 + \lambda$% */
dy = MP_NEW;
}
-
+
dy = F_ADD(f, dy, a->x, dx); /* %$ x + x' $% */
dy = F_MUL(f, dy, dy, lambda); /* %$ (x + x') \lambda$% */
dy = F_ADD(f, dy, dy, a->y); /* %$ (x + x') \lambda + y$% */
{
ec t = EC_INIT;
int rc;
-
+
c->ops->fix(c, &t, p);
rc = eccheck(c, &t);
EC_DESTROY(&t);
static void ecdestroy(ec_curve *c)
{
- ecctx *cc = (ecctx *)c;
+ ecctx_bin *cc = (ecctx_bin *)c;
MP_DROP(cc->c.a);
MP_DROP(cc->c.b);
if (cc->bb) MP_DROP(cc->bb);
ec_curve *ec_bin(field *f, mp *a, mp *b)
{
- ecctx *cc = CREATE(ecctx);
+ ecctx_bin *cc = CREATE(ecctx_bin);
cc->c.ops = &ec_binops;
cc->c.f = f;
cc->c.a = F_IN(f, MP_NEW, a);
ec_curve *ec_binproj(field *f, mp *a, mp *b)
{
- ecctx *cc = CREATE(ecctx);
+ ecctx_bin *cc = CREATE(ecctx_bin);
+ int i;
+ mp *c, *d;
+
cc->c.ops = &ec_binprojops;
cc->c.f = f;
cc->c.a = F_IN(f, MP_NEW, a);
cc->c.b = F_IN(f, MP_NEW, b);
- cc->bb = F_SQRT(f, MP_NEW, cc->c.b);
- if (cc->bb)
- cc->bb = F_SQRT(f, cc->bb, cc->bb);
- if (!cc->bb) {
+
+ c = MP_COPY(cc->c.b);
+ for (i = 0; i < f->nbits - 2; i++)
+ c = F_SQR(f, c, c);
+ d = F_SQR(f, MP_NEW, c); d = F_SQR(f, d, d);
+ if (!MP_EQ(d, cc->c.b)) {
+ MP_DROP(c);
+ MP_DROP(d);
MP_DROP(cc->c.a);
MP_DROP(cc->c.b);
DESTROY(cc);
return (0);
}
+ cc->bb = c;
+ MP_DROP(d);
return (&cc->c);
}
static const ec_ops ec_binops = {
+ "bin",
ecdestroy, ec_stdsamep, ec_idin, ec_idout, ec_idfix,
ecfind, ecneg, ecadd, ec_stdsub, ecdbl, eccheck
};
static const ec_ops ec_binprojops = {
+ "binproj",
ecdestroy, ec_stdsamep, ec_projin, ec_projout, ec_projfix,
ecfind, ecprojneg, ecprojadd, ec_stdsub, ecprojdbl, ecprojcheck
};
g.x = MP(0x0311103c17167564ace77ccb09c681f886ba54ee8);
g.y = MP(0x333ac13c6447f2e67613bf7009daf98c87bb50c7f);
- for (i = 0; i < n; i++) {
+ for (i = 0; i < n; i++) {
ec_mul(c, &d, &g, r);
if (EC_ATINF(&d)) {
fprintf(stderr, "zero too early\n");