X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/343509982ee8c88ddafd0129b4dcf97e3c7a672d..ceb3f0c0a3b7bb3fa3250d31b04c382894095e52:/f-binpoly.c?ds=sidebyside

diff --git a/f-binpoly.c b/f-binpoly.c
new file mode 100644
index 00000000..509efc4f
--- /dev/null
+++ b/f-binpoly.c
@@ -0,0 +1,142 @@
+/* -*-c-*-
+ *
+ * $Id: f-binpoly.c,v 1.1.2.1 2004/03/21 22:39:46 mdw Exp $
+ *
+ * Binary fields with polynomial basis representation
+ *
+ * (c) 2004 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------* 
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * 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: f-binpoly.c,v $
+ * Revision 1.1.2.1  2004/03/21 22:39:46  mdw
+ * Elliptic curves on binary fields work.
+ *
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/sub.h>
+
+#include "field.h"
+#include "gf.h"
+#include "gfreduce.h"
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct fctx {
+  field f;
+  gfreduce r;
+} fctx;
+
+/*----- Main code ---------------------------------------------------------*/
+
+/* --- Field operations --- */
+
+static void fdestroy(field *ff)
+{
+  fctx *f = (fctx *)ff;
+  gfreduce_destroy(&f->r);
+  DESTROY(f);
+}
+
+static int fzerop(field *ff, mp *x)
+{
+  return (!MP_LEN(x));
+}
+
+static mp *fadd(field *ff, mp *d, mp *x, mp *y)
+{
+  return (gf_add(d, x, y));
+}
+
+static mp *fmul(field *ff, mp *d, mp *x, mp *y)
+{
+  fctx *f = (fctx *)ff;
+  d = gf_mul(d, x, y);
+  return (gfreduce_do(&f->r, d, d));
+}
+
+static mp *fsqr(field *ff, mp *d, mp *x)
+{
+  fctx *f = (fctx *)ff;
+  d = gf_sqr(d, x);
+  return (gfreduce_do(&f->r, d, d));
+}
+
+static mp *finv(field *ff, mp *d, mp *x)
+{
+  fctx *f = (fctx *)ff;
+  gf_gcd(0, 0, &d, f->r.p, x);
+  return (d);
+}
+
+static mp *freduce(field *ff, mp *d, mp *x)
+{
+  fctx *f = (fctx *)ff;
+  return (gfreduce_do(&f->r, d, x));
+}
+
+static mp *fsqrt(field *ff, mp *d, mp *x)
+{
+  fctx *f = (fctx *)ff;
+  return (gfreduce_sqrt(&f->r, d, x));
+}
+
+static mp *fquadsolve(field *ff, mp *d, mp *x)
+{
+  fctx *f = (fctx *)ff;
+  return (gfreduce_quadsolve(&f->r, d, x));
+}
+
+/* --- Field operations table --- */
+
+static field_ops fops = {
+  fdestroy,
+  freduce, field_id,
+  fzerop, field_id, fadd, fadd, fmul, fsqr, finv, freduce, fsqrt,
+  fquadsolve,
+  0, 0, 0, 0
+};
+
+/* --- @field_binpoly@ --- *
+ *
+ * Arguments:	@mp *p@ = the reduction polynomial
+ *
+ * Returns:	A pointer to the field.
+ *
+ * Use:		Creates a field structure for a binary field mod @p@.
+ */
+
+field *field_binpoly(mp *p)
+{
+  fctx *f = CREATE(fctx);
+  f->f.ops = &fops;
+  f->f.zero = MP_ZERO;
+  f->f.one = MP_ONE;
+  gfreduce_create(&f->r, p);
+  return (&f->f);
+}
+
+/*----- That's all, folks -------------------------------------------------*/