X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/a2a74efe4b1276b1efec12f25fd65f0df060f38a..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/calc/ecp.cal

diff --git a/calc/ecp.cal b/calc/ecp.cal
index 04971aa..700b18f 100644
--- a/calc/ecp.cal
+++ b/calc/ecp.cal
@@ -1,13 +1,11 @@
 /* -*-apcalc-*-
  *
- * $Id: ecp.cal,v 1.1 2000/10/08 16:01:37 mdw Exp $
- *
  * Testbed for elliptic curve arithmetic over prime fields
  *
  * (c) 2000 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,26 +13,18 @@
  * 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: ecp.cal,v $
- * Revision 1.1  2000/10/08 16:01:37  mdw
- * Prototypes of various bits of code.
- *
- */
-
 /*----- Object types ------------------------------------------------------*/
 
 obj ecp_curve { a, b, p };
@@ -82,7 +72,7 @@ define ecp_pt_add(a, b)
     e = a.e;
     if (a.x == b.x) {
       if (a.y != b.y) {
-        return (0);
+	return (0);
       }
       alpha = (3 * a.x^2 + e.a) * minv(2 * a.y, e.p) % e.p;
     } else
@@ -96,15 +86,38 @@ define ecp_pt_add(a, b)
   return (d);
 }
 
+define ecp_pt_dbl(a)
+{
+  local e, alpha;
+  local obj ecp_pt d;
+  if (istype(a, 1))
+    return (0);
+  e = a.e;
+  alpha = (3 * a.x^2 + e.a) * minv(2 * a.y, e.p) % e.p;
+  d.x = (alpha^2 - 2 * a.x) % e.p;
+  d.y = (-a.y + alpha * (a.x - d.x)) % e.p;
+  d.e = e;
+  return (d);
+}
+
 define ecp_pt_neg(a)
 {
   local obj ecp_pt d;
   d.x = a.x;
-  d.y = -a.y;
+  d.y = a.e.p - a.y;
   d.e = a.e;
   return (d);
 }
 
+define ecp_pt_check(a)
+{
+  local e;
+
+  e = a.e;
+  if (a.y^2 % e.p != (a.x^3 + e.a * a.x + e.b) % e.p)
+    quit "bad curve point";
+}
+
 define ecp_pt_mul(a, b)
 {
   local p, n;
@@ -124,10 +137,18 @@ define ecp_pt_mul(a, b)
     if (n & 1)
       d += p;
     n >>= 1;
-    p += p;
+    p = ecp_pt_dbl(p);
   }
   return (d);
 }
 
+/*----- FIPS186-2 standard curves -----------------------------------------*/
+
+p192 = ecp_curve(-3, 0x64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1,
+		 6277101735386680763835789423207666416083908700390324961279);
+p192_r = 6277101735386680763835789423176059013767194773182842284081;
+p192_g = ecp_pt(0x188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012,
+		0x07192b95ffc8da78631011ed6b24cdd573f977a11e794811, p192);
+
 /*----- That's all, folks -------------------------------------------------*/