Raw I/O of elliptic curve points and group elements.

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

diff --git a/g-prime.c b/g-prime.c
index 03cce55..97f455f 100644 (file)
--- a/g-prime.c
+++ b/g-prime.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: g-prime.c,v 1.2 2004/04/03 03:32:05 mdw Exp $
+ * $Id: g-prime.c,v 1.3 2004/04/04 19:04:11 mdw Exp $
  *
  * Abstraction for prime groups
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: g-prime.c,v $
+ * Revision 1.3  2004/04/04 19:04:11  mdw
+ * Raw I/O of elliptic curve points and group elements.
+ *
  * Revision 1.2  2004/04/03 03:32:05  mdw
  * General robustification.
  *
@@ -149,6 +152,20 @@ static int gfrombuf(group *gg, buf *b, mp **d) {
   *d = mpmont_mul(&g->mm, x, x, g->mm.r2); return(0);
 }
 
+static int gtoraw(group *gg, buf *b, mp **x) {
+  gctx *g = (gctx *)gg; octet *q; mp *t = mpmont_reduce(&g->mm, MP_NEW, *x);
+  if ((q = buf_get(b, g->g.noctets)) == 0) { MP_DROP(t); return (-1); }
+  mp_storeb(t, q, g->g.noctets); MP_DROP(t); return (0);
+}
+
+static int gfromraw(group *gg, buf *b, mp **d) {
+  gctx * g = (gctx *)gg; mp *x; octet *q;
+  if ((q = buf_get(b, g->g.noctets)) == 0) return (-1);
+  x = mp_loadb(MP_NEW, q, g->g.noctets);
+  mp_div(0, &x, x, g->mm.m); mp_drop(*d);
+  *d = mpmont_mul(&g->mm, x, x, g->mm.r2); return(0);
+}
+
 /* --- @group_prime@ --- *
  *
  * Arguments:  @const gprime_param *gp@ = group parameters
@@ -166,7 +183,8 @@ static const group_ops gops = {
   gcheck,
   gmul, gsqr, ginv, group_stddiv, gexp, gmexp,
   gread, gwrite,
-  gtoint, gfromint, group_stdtoec, group_stdfromec, gtobuf, gfrombuf
+  gtoint, gfromint, group_stdtoec, group_stdfromec, gtobuf, gfrombuf,
+  gtoraw, gfromraw
 };
 
 group *group_prime(const gprime_param *gp)