perftest: Document the `-q' option for disabling checking.

[u/mdw/catacomb] / ec-prime.c

diff --git a/ec-prime.c b/ec-prime.c
index 41ba9c4..52815e4 100644 (file)
--- a/ec-prime.c
+++ b/ec-prime.c
@@ -1,13 +1,13 @@
 /* -*-c-*-
  *
- * $Id: ec-prime.c,v 1.10 2004/04/03 03:32:05 mdw Exp $
+ * $Id$
  *
  * Elliptic curves over prime fields
  *
  * (c) 2001 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,68 +15,18 @@
  * 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,
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: ec-prime.c,v $
- * Revision 1.10  2004/04/03 03:32:05  mdw
- * General robustification.
- *
- * Revision 1.9  2004/04/01 12:50:09  mdw
- * Add cyclic group abstraction, with test code.  Separate off exponentation
- * functions for better static linking.  Fix a buttload of bugs on the way.
- * Generally ensure that negative exponents do inversion correctly.  Add
- * table of standard prime-field subgroups.  (Binary field subgroups are
- * currently unimplemented but easy to add if anyone ever finds a good one.)
- *
- * Revision 1.8  2004/03/27 17:54:11  mdw
- * Standard curves and curve checking.
- *
- * Revision 1.7  2004/03/27 00:04:46  mdw
- * Implement efficient reduction for pleasant-looking primes.
- *
- * Revision 1.6  2004/03/23 15:19:32  mdw
- * Test elliptic curves more thoroughly.
- *
- * Revision 1.5  2004/03/22 02:19:10  mdw
- * Rationalise the sliding-window threshold.  Drop guarantee that right
- * arguments to EC @add@ are canonical, and fix up projective implementations
- * to cope.
- *
- * Revision 1.4  2004/03/21 22:52:06  mdw
- * Merge and close elliptic curve branch.
- *
- * Revision 1.3.4.3  2004/03/21 22:39:46  mdw
- * Elliptic curves on binary fields work.
- *
- * Revision 1.3.4.2  2004/03/20 00:13:31  mdw
- * Projective coordinates for prime curves
- *
- * Revision 1.3.4.1  2003/06/10 13:43:53  mdw
- * Simple (non-projective) curves over prime fields now seem to work.
- *
- * Revision 1.3  2003/05/15 23:25:59  mdw
- * Make elliptic curve stuff build.
- *
- * Revision 1.2  2002/01/13 13:48:44  mdw
- * Further progress.
- *
- * Revision 1.1  2001/04/29 18:12:33  mdw
- * Prototype version.
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include <mLib/sub.h>
@@ -118,10 +68,8 @@ static ec *ecfind(ec_curve *c, ec *d, mp *x)
 
 static ec *ecdbl(ec_curve *c, ec *d, const ec *a)
 {
-  if (EC_ATINF(a))
+  if (EC_ATINF(a) || F_ZEROP(c->f, a->y))
     EC_SETINF(d);
-  else if (F_ZEROP(c->f, a->y))
-    EC_COPY(d, a);
   else {
     field *f = c->f;
     mp *lambda;
@@ -152,10 +100,8 @@ static ec *ecdbl(ec_curve *c, ec *d, const ec *a)
 
 static ec *ecprojdbl(ec_curve *c, ec *d, const ec *a)
 {
-  if (EC_ATINF(a))
+  if (EC_ATINF(a) || F_ZEROP(c->f, a->y))
     EC_SETINF(d);
-  else if (F_ZEROP(c->f, a->y))
-    EC_COPY(d, a);
   else {
     field *f = c->f;
     mp *p, *q, *m, *s, *dx, *dy, *dz;
@@ -196,10 +142,8 @@ static ec *ecprojdbl(ec_curve *c, ec *d, const ec *a)
 
 static ec *ecprojxdbl(ec_curve *c, ec *d, const ec *a)
 {
-  if (EC_ATINF(a))
+  if (EC_ATINF(a) || F_ZEROP(c->f, a->y))
     EC_SETINF(d);
-  else if (F_ZEROP(c->f, a->y))
-    EC_COPY(d, a);
   else {
     field *f = c->f;
     mp *p, *q, *m, *s, *dx, *dy, *dz;
@@ -334,7 +278,7 @@ static ec *ecprojadd(ec_curve *c, ec *d, const ec *a, const ec *b)
     q = F_MUL(f, MP_NEW, p, u);                /* %$t w^2$% */
     u = F_MUL(f, u, p, w);             /* %$w^3$% */
     p = F_MUL(f, p, u, s);             /* %$m w^3$% */
-    
+
     dx = F_SQR(f, u, r);               /* %$r^2$% */
     dx = F_SUB(f, dx, dx, q);          /* %$x' = r^2 - t w^2$% */
 
@@ -379,7 +323,7 @@ static int ecprojcheck(ec_curve *c, const ec *p)
 {
   ec t = EC_INIT;
   int rc;
-  
+
   c->ops->fix(c, &t, p);
   rc = eccheck(c, &t);
   EC_DESTROY(&t);
@@ -434,16 +378,19 @@ extern ec_curve *ec_primeproj(field *f, mp *a, mp *b)
 }
 
 static const ec_ops ec_primeops = {
+  "prime",
   ecdestroy, ec_stdsamep, ec_idin, ec_idout, ec_idfix,
   ecfind, ecneg, ecadd, ec_stdsub, ecdbl, eccheck
 };
 
 static const ec_ops ec_primeprojops = {
+  "primeproj",
   ecdestroy, ec_stdsamep, ec_projin, ec_projout, ec_projfix,
   ecfind, ecneg, ecprojadd, ec_stdsub, ecprojdbl, ecprojcheck
 };
 
 static const ec_ops ec_primeprojxops = {
+  "primeproj",
   ecdestroy, ec_stdsamep, ec_projin, ec_projout, ec_projfix,
   ecfind, ecneg, ecprojadd, ec_stdsub, ecprojxdbl, ecprojcheck
 };
@@ -471,11 +418,11 @@ int main(int argc, char *argv[])
 
   f = field_niceprime(p);
   c = ec_primeproj(f, a, b);
-  
+
   g.x = MP(0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760ab7);
   g.y = MP(0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5f);
 
-  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");