--- /dev/null
+/* -*-c-*-
+ *
+ * $Id: gfreduce.h,v 1.1.2.1 2004/03/21 22:39:46 mdw Exp $
+ *
+ * Reduction modulo sparse binary polynomials
+ *
+ * (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: gfreduce.h,v $
+ * Revision 1.1.2.1 2004/03/21 22:39:46 mdw
+ * Elliptic curves on binary fields work.
+ *
+ */
+
+#ifndef CATACOMB_GFREDUCE_H
+#define CATACOMB_GFREDUCE_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#ifndef CATACOMB_GF_H
+# include "gf.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+typedef struct gfreduce_instr {
+ unsigned op; /* Instruction opcode */
+ size_t arg; /* Immediate argument */
+} gfreduce_instr;
+
+enum {
+ GFRI_LOAD, /* Load @p[arg]@ */
+ GFRI_LSL, /* XOR with @w << arg@ */
+ GFRI_LSR, /* XOR with @w >> arg@ */
+ GFRI_STORE, /* Store @p[arg]@ */
+ GFRI_MAX
+};
+
+typedef struct gfreduce {
+ size_t lim; /* Word of degree bit */
+ mpw mask; /* Mask for degree word */
+ mp *p; /* Copy of the polynomial */
+ size_t in; /* Number of instruction words */
+ gfreduce_instr *iv, *liv; /* Vector of instructions */
+} gfreduce;
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @gfreduce_create@ --- *
+ *
+ * Arguments: @gfreduce *r@ = structure to fill in
+ * @mp *x@ = a (hopefully sparse) polynomial
+ *
+ * Returns: ---
+ *
+ * Use: Initializes a context structure for reduction.
+ */
+
+extern void gfreduce_create(gfreduce */*r*/, mp */*p*/);
+
+/* --- @gfreduce_destroy@ --- *
+ *
+ * Arguments: @gfreduce *r@ = structure to free
+ *
+ * Returns: ---
+ *
+ * Use: Reclaims the resources from a reduction context.
+ */
+
+extern void gfreduce_destroy(gfreduce */*r*/);
+
+/* --- @gfreduce_dump@ --- *
+ *
+ * Arguments: @gfreduce *r@ = structure to dump
+ * @FILE *fp@ = file to dump on
+ *
+ * Returns: ---
+ *
+ * Use: Dumps a reduction context.
+ */
+
+extern void gfreduce_dump(gfreduce */*r*/, FILE */*fp*/);
+
+/* --- @gfreduce_do@ --- *
+ *
+ * Arguments: @gfreduce *r@ = reduction context
+ * @mp *d@ = destination
+ * @mp *x@ = source
+ *
+ * Returns: Destination, @x@ reduced modulo the reduction poly.
+ */
+
+extern mp *gfreduce_do(gfreduce */*r*/, mp */*d*/, mp */*x*/);
+
+/* --- @gfreduce_sqrt@ --- *
+ *
+ * Arguments: @gfreduce *r@ = pointer to reduction context
+ * @mp *d@ = destination
+ * @mp *x@ = some polynomial
+ *
+ * Returns: The square root of @x@ modulo @r->p@, or null.
+ */
+
+extern mp *gfreduce_sqrt(gfreduce */*r*/, mp */*d*/, mp */*x*/);
+
+/* --- @gfreduce_trace@ --- *
+ *
+ * Arguments: @gfreduce *r@ = pointer to reduction context
+ * @mp *x@ = some polynomial
+ *
+ * Returns: The trace of @x@. (%$\Tr(x)=x + x^2 + \cdots + x^{2^{m-1}}$%
+ * if %$x \in \gf{2^m}$%).
+ */
+
+extern int gfreduce_trace(gfreduce */*r*/, mp */*x*/);
+
+/* --- @gfreduce_halftrace@ --- *
+ *
+ * Arguments: @gfreduce *r@ = pointer to reduction context
+ * @mp *d@ = destination
+ * @mp *x@ = some polynomial
+ *
+ * Returns: The half-trace of @x@.
+ * (%$\HfTr(x)= x + x^{2^2} + \cdots + x^{2^{m-1}}$%
+ * if %$x \in \gf{2^m}$% with %$m$% odd).
+ */
+
+extern mp *gfreduce_halftrace(gfreduce */*r*/, mp */*d*/, mp */*x*/);
+
+/* --- @gfreduce_quadsolve@ --- *
+ *
+ * Arguments: @gfreduce *r@ = pointer to reduction context
+ * @mp *d@ = destination
+ * @mp *x@ = some polynomial
+ *
+ * Returns: A polynomial @y@ such that %$y^2 + y = x$%, or null.
+ */
+
+extern mp *gfreduce_quadsolve(gfreduce */*r*/, mp */*d*/, mp */*x*/);
+
+/* --- @gfreduce_exp@ --- *
+ *
+ * Arguments: @gfreduce *gr@ = pointer to reduction context
+ * @mp *d@ = fake destination
+ * @mp *a@ = base
+ * @mp *e@ = exponent
+ *
+ * Returns: Result, %$a^e \bmod m$%.
+ */
+
+extern mp *gfreduce_exp(gfreduce */*gr*/, mp */*d*/, mp */*a*/, mp */*e*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif