X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ceb3f0c0a3b7bb3fa3250d31b04c382894095e52..b2776fdf2a98ea586bbdad50eca4ed95e967b0d7:/gf.h

diff --git a/gf.h b/gf.h
index 889cd9b..8de8231 100644
--- a/gf.h
+++ b/gf.h
@@ -1,13 +1,13 @@
 /* -*-c-*-
  *
- * $Id: gf.h,v 1.1.2.1 2004/03/21 22:39:46 mdw Exp $
+ * $Id$
  *
  * Arithmetic on binary polynomials
  *
  * (c) 2004 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,26 +15,18 @@
  * 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: gf.h,v $
- * Revision 1.1.2.1  2004/03/21 22:39:46  mdw
- * Elliptic curves on binary fields work.
- *
- */
-
 #ifndef CATACOMB_GF_H
 #define CATACOMB_GF_H
 
@@ -99,6 +91,26 @@ extern mp *gf_sqr(mp */*d*/, mp */*a*/);
 
 extern void gf_div(mp **/*qq*/, mp **/*rr*/, mp */*a*/, mp */*b*/);
 
+/* --- @gf_exp@ --- *
+ *
+ * Arguments:	@mp *d@ = fake destination
+ *		@mp *a@ = base
+ *		@mp *e@ = exponent
+ *
+ * Returns:	Result, %$a^e$%.
+ */
+
+extern mp *gf_exp(mp */*d*/, mp */*a*/, mp */*e*/);
+
+/* --- @gf_irreduciblep@ --- *
+ *
+ * Arguments:	@mp *f@ = a polynomial
+ *
+ * Returns:	Nonzero if the polynomial is irreducible; otherwise zero.
+ */
+
+extern int gf_irreduciblep(mp */*f*/);
+
 /* --- @gf_gcd@ --- *
  *
  * Arguments:	@mp **gcd, **xx, **yy@ = where to write the results
@@ -115,6 +127,21 @@ extern void gf_div(mp **/*qq*/, mp **/*rr*/, mp */*a*/, mp */*b*/);
 extern void gf_gcd(mp **/*gcd*/, mp **/*xx*/, mp **/*yy*/,
 		   mp */*a*/, mp */*b*/);
 
+/* -- @gf_modinv@ --- *
+ *
+ * Arguments:	@mp *d@ = destination
+ *		@mp *x@ = argument
+ *		@mp *p@ = modulus
+ *
+ * Returns:	The inverse %$x^{-1} \bmod p$%.
+ *
+ * Use:		Computes a modular inverse, the catch being that the
+ *		arguments and results are binary polynomials.  An assertion
+ *		fails if %$p$% has no inverse.
+ */
+
+extern mp *gf_modinv(mp */*d*/, mp */*x*/, mp */*p*/);
+
 /*----- That's all, folks -------------------------------------------------*/
 
 #ifdef __cplusplus