Standard curves and curve checking.

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

diff --git a/ec-prime.c b/ec-prime.c
index 7712bbf..ce81ba1 100644 (file)
--- a/ec-prime.c
+++ b/ec-prime.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: ec-prime.c,v 1.7 2004/03/27 00:04:46 mdw Exp $
+ * $Id: ec-prime.c,v 1.8 2004/03/27 17:54:11 mdw Exp $
  *
  * Elliptic curves over prime fields
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: ec-prime.c,v $
+ * 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.
  *
@@ -70,13 +73,6 @@
 
 #include "ec.h"
 
-/*----- Data structures ---------------------------------------------------*/
-
-typedef struct ecctx {
-  ec_curve c;
-  mp *a, *b;
-} ecctx;
-
 /*----- Simple prime curves -----------------------------------------------*/
 
 static const ec_ops ec_primeops, ec_primeprojops, ec_primeprojxops;
@@ -92,14 +88,13 @@ static ec *ecneg(ec_curve *c, ec *d, const ec *p)
 static ec *ecfind(ec_curve *c, ec *d, mp *x)
 {
   mp *p, *q;
-  ecctx *cc = (ecctx *)c;
   field *f = c->f;
 
   q = F_SQR(f, MP_NEW, x);
   p = F_MUL(f, MP_NEW, x, q);
-  q = F_MUL(f, q, x, cc->a);
+  q = F_MUL(f, q, x, c->a);
   p = F_ADD(f, p, p, q);
-  p = F_ADD(f, p, p, cc->b);
+  p = F_ADD(f, p, p, c->b);
   MP_DROP(q);
   p = F_SQRT(f, p, p);
   if (!p)
@@ -119,14 +114,13 @@ static ec *ecdbl(ec_curve *c, ec *d, const ec *a)
     EC_COPY(d, a);
   else {
     field *f = c->f;
-    ecctx *cc = (ecctx *)c;
     mp *lambda;
     mp *dy, *dx;
 
     dx = F_SQR(f, MP_NEW, a->x);       /* %$x^2$% */
     dy = F_DBL(f, MP_NEW, a->y);       /* %$2 y$% */
     dx = F_TPL(f, dx, dx);             /* %$3 x^2$% */
-    dx = F_ADD(f, dx, dx, cc->a);      /* %$3 x^2 + A$% */
+    dx = F_ADD(f, dx, dx, c->a);       /* %$3 x^2 + A$% */
     dy = F_INV(f, dy, dy);             /* %$(2 y)^{-1}$% */
     lambda = F_MUL(f, MP_NEW, dx, dy); /* %$\lambda = (3 x^2 + A)/(2 y)$% */
 
@@ -154,12 +148,11 @@ static ec *ecprojdbl(ec_curve *c, ec *d, const ec *a)
     EC_COPY(d, a);
   else {
     field *f = c->f;
-    ecctx *cc = (ecctx *)c;
     mp *p, *q, *m, *s, *dx, *dy, *dz;
 
     p = F_SQR(f, MP_NEW, a->z);                /* %$z^2$% */
     q = F_SQR(f, MP_NEW, p);           /* %$z^4$% */
-    p = F_MUL(f, p, q, cc->a);         /* %$A z^4$% */
+    p = F_MUL(f, p, q, c->a);          /* %$A z^4$% */
     m = F_SQR(f, MP_NEW, a->x);                /* %$x^2$% */
     m = F_TPL(f, m, m);                        /* %$3 x^2$% */
     m = F_ADD(f, m, m, p);             /* %$m = 3 x^2 + A z^4$% */
@@ -257,10 +250,9 @@ static ec *ecadd(ec_curve *c, ec *d, const ec *a, const ec *b)
       EC_SETINF(d);
       return (d);
     } else {
-      ecctx *cc = (ecctx *)c;
       dx = F_SQR(f, MP_NEW, a->x);     /* %$x_0^2$% */
       dx = F_TPL(f, dx, dx);           /* %$3 x_0^2$% */
-      dx = F_ADD(f, dx, dx, cc->a);    /* %$3 x_0^2 + A$% */
+      dx = F_ADD(f, dx, dx, c->a);     /* %$3 x_0^2 + A$% */
       dy = F_DBL(f, MP_NEW, a->y);     /* %$2 y_0$% */
       dy = F_INV(f, dy, dy);           /* %$(2 y_0)^{-1}$% */
       lambda = F_MUL(f, MP_NEW, dx, dy);
@@ -356,15 +348,14 @@ static ec *ecprojadd(ec_curve *c, ec *d, const ec *a, const ec *b)
 
 static int eccheck(ec_curve *c, const ec *p)
 {
-  ecctx *cc = (ecctx *)c;
   field *f = c->f;
   int rc;
   mp *l = F_SQR(f, MP_NEW, p->y);
   mp *x = F_SQR(f, MP_NEW, p->x);
   mp *r = F_MUL(f, MP_NEW, x, p->x);
-  x = F_MUL(f, x, cc->a, p->x);
+  x = F_MUL(f, x, c->a, p->x);
   r = F_ADD(f, r, r, x);
-  r = F_ADD(f, r, r, cc->b);
+  r = F_ADD(f, r, r, c->b);
   rc = MP_EQ(l, r) ? 0 : -1;
   mp_drop(l);
   mp_drop(x);
@@ -385,10 +376,9 @@ static int ecprojcheck(ec_curve *c, const ec *p)
 
 static void ecdestroy(ec_curve *c)
 {
-  ecctx *cc = (ecctx *)c;
-  MP_DROP(cc->a);
-  MP_DROP(cc->b);
-  DESTROY(cc);
+  MP_DROP(c->a);
+  MP_DROP(c->b);
+  DESTROY(c);
 }
 
 /* --- @ec_prime@, @ec_primeproj@ --- *
@@ -405,30 +395,30 @@ static void ecdestroy(ec_curve *c)
 
 extern ec_curve *ec_prime(field *f, mp *a, mp *b)
 {
-  ecctx *cc = CREATE(ecctx);
-  cc->c.ops = &ec_primeops;
-  cc->c.f = f;
-  cc->a = F_IN(f, MP_NEW, a);
-  cc->b = F_IN(f, MP_NEW, b);
-  return (&cc->c);
+  ec_curve *c = CREATE(ec_curve);
+  c->ops = &ec_primeops;
+  c->f = f;
+  c->a = F_IN(f, MP_NEW, a);
+  c->b = F_IN(f, MP_NEW, b);
+  return (c);
 }
 
 extern ec_curve *ec_primeproj(field *f, mp *a, mp *b)
 {
-  ecctx *cc = CREATE(ecctx);
+  ec_curve *c = CREATE(ec_curve);
   mp *ax;
 
   ax = mp_add(MP_NEW, a, MP_THREE);
   ax = F_IN(f, ax, ax);
   if (F_ZEROP(f, ax))
-    cc->c.ops = &ec_primeprojxops;
+    c->ops = &ec_primeprojxops;
   else
-    cc->c.ops = &ec_primeprojops;
+    c->ops = &ec_primeprojops;
   MP_DROP(ax);
-  cc->c.f = f;
-  cc->a = F_IN(f, MP_NEW, a);
-  cc->b = F_IN(f, MP_NEW, b);
-  return (&cc->c);
+  c->f = f;
+  c->a = F_IN(f, MP_NEW, a);
+  c->b = F_IN(f, MP_NEW, b);
+  return (c);
 }
 
 static const ec_ops ec_primeops = {
@@ -463,15 +453,15 @@ int main(int argc, char *argv[])
   printf("ec-prime: ");
   fflush(stdout);
   a = MP(-3);
-  b = MP(0x64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1);
-  p = MP(6277101735386680763835789423207666416083908700390324961279);
-  r = MP(6277101735386680763835789423176059013767194773182842284080);
+  b = MP(0xb3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875ac656398d8a2ed19d2a85c8edd3ec2aef);
+  p = MP(39402006196394479212279040100143613805079739270465446667948293404245721771496870329047266088258938001861606973112319);
+  r = MP(39402006196394479212279040100143613805079739270465446667946905279627659399113263569398956308152294913554433653942642);
 
   f = field_niceprime(p);
   c = ec_primeproj(f, a, b);
   
-  g.x = MP(0x188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012);
-  g.y = MP(0x07192b95ffc8da78631011ed6b24cdd573f977a11e794811);
+  g.x = MP(0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760ab7);
+  g.y = MP(0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5f);
 
   for (i = 0; i < n; i++) { 
     ec_mul(c, &d, &g, r);