X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/34e4f738bcba58e6d8c4cabbb0b3232a65b42a9d..813390c45f438f411662b1a55678e63f11681eb4:/group-stdops.c

diff --git a/group-stdops.c b/group-stdops.c
index 2e3e6d4..77f48f7 100644
--- a/group-stdops.c
+++ b/group-stdops.c
@@ -1,13 +1,13 @@
 /* -*-c-*-
  *
- * $Id: group-stdops.c,v 1.1 2004/04/01 12:50:09 mdw Exp $
+ * $Id$
  *
  * Standard group operations
  *
  * (c) 2004 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,30 +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: group-stdops.c,v $
- * Revision 1.1  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.)
- *
- */
-
 /*----- Header files ------------------------------------------------------*/
 
 #include "group.h"
@@ -54,7 +42,7 @@
  * Returns:	Zero on success, nonzero for failure.
  *
  * Use:		Checks that @x@ is a valid group element.  This may take a
- *		while, since it checks that %$x^h \ne 1$% and %$x^r = 1$%.
+ *		while, since it checks that %$x \ne 1$% and %$x^r = 1$%.
  */
 
 int group_check(group *g, ge *x)
@@ -62,8 +50,8 @@ int group_check(group *g, ge *x)
   ge *d = G_CREATE(g);
   int rc;
 
-  G_EXP(g, d, x, g->h); rc = !G_IDENTP(g, d);
-  if (rc) { G_EXP(g, d, x, g->r); rc = G_IDENTP(g, d); }
+  G_EXP(g, d, x, g->r);
+  rc = (G_IDENTP(g, d) && !G_IDENTP(g, x));
   G_DESTROY(g, d);
   if (!rc) return (-1);
   return (0);
@@ -83,10 +71,10 @@ int group_check(group *g, ge *x)
 
 int group_samep(group *g, group *h)
 {
-  return (g->ops == h->ops &&
-	  MP_EQ(g->r, h->r) && MP_EQ(g->h, h->h) &&
-	  G_EQ(g, g->i, h->i) && G_EQ(g, g->g, h->g) &&
-	  G_SAMEP(g, h));
+  return (g == h || (g->ops == h->ops &&
+		     MP_EQ(g->r, h->r) && MP_EQ(g->h, h->h) &&
+		     G_EQ(g, g->i, h->i) && G_EQ(g, g->g, h->g) &&
+		     G_SAMEP(g, h)));
 }
 
 /*----- Standard implementations ------------------------------------------*/
@@ -127,10 +115,7 @@ void group_stdsqr(group *g, ge *d, ge *x) { G_MUL(g, d, x, x); }
  */
 
 void group_stddiv(group *g, ge *d, ge *x, ge *y)
-{
-  G_INV(g, d, y);
-  G_MUL(g, d, x, d);
-}
+  { G_INV(g, d, y); G_MUL(g, d, x, d); }
 
 /* --- @group_stdtoec@ --- *
  *
@@ -149,7 +134,7 @@ int group_stdtoec(group *g, ec *d, ge *x) { return (-1); }
  *
  * Arguments:	@group *g@ = abstract group
  *		@ge *d@ = destination pointer
- *		@ec *p@ = elliptic curve point
+ *		@const ec *p@ = elliptic curve point
  *
  * Returns:	Zero for success, @-1@ on failure.
  *
@@ -157,7 +142,7 @@ int group_stdtoec(group *g, ec *d, ge *x) { return (-1); }
  *		coordinate.
  */
 
-int group_stdfromec(group *g, ge *d, ec *p)
+int group_stdfromec(group *g, ge *d, const ec *p)
   { if (EC_ATINF(p)) return (-1); return (G_FROMINT(g, d, p->x)); }
 
 /* --- @group_stdcheck@ --- *