From 9b8b6877809f0626e8e3eff1f731b1daa796fecb Mon Sep 17 00:00:00 2001
From: mdw <mdw>
Date: Tue, 23 Mar 2004 12:08:26 +0000
Subject: [PATCH] Random field-element selection.

---
 f-binpoly.c | 14 ++++++++++++--
 f-prime.c   | 14 ++++++++++++--
 field.h     | 10 +++++++++-
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/f-binpoly.c b/f-binpoly.c
index 02e683d..463dbb2 100644
--- a/f-binpoly.c
+++ b/f-binpoly.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: f-binpoly.c,v 1.2 2004/03/21 22:52:06 mdw Exp $
+ * $Id: f-binpoly.c,v 1.3 2004/03/23 12:08:26 mdw Exp $
  *
  * Binary fields with polynomial basis representation
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: f-binpoly.c,v $
+ * Revision 1.3  2004/03/23 12:08:26  mdw
+ * Random field-element selection.
+ *
  * Revision 1.2  2004/03/21 22:52:06  mdw
  * Merge and close elliptic curve branch.
  *
@@ -45,6 +48,7 @@
 #include "field.h"
 #include "gf.h"
 #include "gfreduce.h"
+#include "mprand.h"
 
 /*----- Data structures ---------------------------------------------------*/
 
@@ -64,6 +68,12 @@ static void fdestroy(field *ff)
   DESTROY(f);
 }
 
+static mp *frand(field *ff, grand *r, mp *d)
+{
+  fctx *f = (fctx *)ff;
+  return (mprand(d, mp_octets(f->r.p) - 1, r, 0));
+}
+
 static int fzerop(field *ff, mp *x)
 {
   return (!MP_LEN(x));
@@ -116,7 +126,7 @@ static mp *fquadsolve(field *ff, mp *d, mp *x)
 /* --- Field operations table --- */
 
 static field_ops fops = {
-  fdestroy,
+  fdestroy, frand,
   freduce, field_id,
   fzerop, field_id, fadd, fadd, fmul, fsqr, finv, freduce, fsqrt,
   fquadsolve,
diff --git a/f-prime.c b/f-prime.c
index 8454902..5ab4204 100644
--- a/f-prime.c
+++ b/f-prime.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: f-prime.c,v 1.4 2004/03/21 22:52:06 mdw Exp $
+ * $Id: f-prime.c,v 1.5 2004/03/23 12:08:26 mdw Exp $
  *
  * Prime fields with Montgomery arithmetic
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: f-prime.c,v $
+ * Revision 1.5  2004/03/23 12:08:26  mdw
+ * Random field-element selection.
+ *
  * Revision 1.4  2004/03/21 22:52:06  mdw
  * Merge and close elliptic curve branch.
  *
@@ -59,6 +62,7 @@
 
 #include "field.h"
 #include "mpmont.h"
+#include "mprand.h"
 
 /*----- Data structures ---------------------------------------------------*/
 
@@ -78,6 +82,12 @@ static void fdestroy(field *ff)
   DESTROY(f);
 }
 
+static mp *frand(field *ff, mp *d, grand *r)
+{
+  fctx *f = (fctx *)ff;
+  return (mprand_range(d, f->mm.m, r, 0));
+}
+
 static mp *fin(field *ff, mp *d, mp *x)
 {
   fctx *f = (fctx *)ff;
@@ -208,7 +218,7 @@ static mp *fhlv(field *ff, mp *d, mp *x)
 /* --- Field operations table --- */
 
 static field_ops fops = {
-  fdestroy,
+  fdestroy, frand,
   fin, fout,
   fzerop, fneg, fadd, fsub, fmul, fsqr, finv, freduce, fsqrt,
   0,
diff --git a/field.h b/field.h
index dd674c9..909332f 100644
--- a/field.h
+++ b/field.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: field.h,v 1.4 2004/03/21 22:52:06 mdw Exp $
+ * $Id: field.h,v 1.5 2004/03/23 12:08:26 mdw Exp $
  *
  * Definitions for field arithmetic
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: field.h,v $
+ * Revision 1.5  2004/03/23 12:08:26  mdw
+ * Random field-element selection.
+ *
  * Revision 1.4  2004/03/21 22:52:06  mdw
  * Merge and close elliptic curve branch.
  *
@@ -59,6 +62,10 @@
 
 /*----- Header files ------------------------------------------------------*/
 
+#ifndef CATACOMB_GRAND_H
+#  include "grand.h"
+#endif
+
 #ifndef CATACOMB_MP_H
 #  include "mp.h"
 #endif
@@ -75,6 +82,7 @@ typedef struct field_ops {
   /* --- Universal operations --- */
 
   void (*destroy)(field */*f*/);
+  mp *(*rand)(field */*f*/, mp */*d*/, grand */*r*/);
 
   mp *(*in)(field */*f*/, mp */*d*/, mp */*x*/);
   mp *(*out)(field */*f*/, mp */*d*/, mp */*x*/);
-- 
2.11.0