5 * Arithmetic on binary polynomials
7 * (c) 2004 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
37 /*----- Header files ------------------------------------------------------*/
43 #ifndef CATACOMB_GFX_H
47 /*----- Functions provided ------------------------------------------------*/
51 * Arguments: @mp *d@ = destination
52 * @mp *a, *b@ = sources
54 * Returns: Result, @a@ added to @b@.
57 extern mp
*gf_add(mp */
*d*/
, mp */
*a*/
, mp */
*b*/
);
62 * Arguments: @mp *d@ = destination
63 * @mp *a, *b@ = sources
65 * Returns: Result, @a@ multiplied by @b@.
68 extern mp
*gf_mul(mp */
*d*/
, mp */
*a*/
, mp */
*b*/
);
72 * Arguments: @mp *d@ = destination
75 * Returns: Result, @a@ squared.
78 extern mp
*gf_sqr(mp */
*d*/
, mp */
*a*/
);
82 * Arguments: @mp **qq, **rr@ = destination, quotient and remainder
83 * @mp *a, *b@ = sources
85 * Use: Calculates the quotient and remainder when @a@ is divided by
86 * @b@. The destinations @*qq@ and @*rr@ must be distinct.
87 * Either of @qq@ or @rr@ may be null to indicate that the
88 * result is irrelevant. (Discarding both results is silly.)
89 * There is a performance advantage if @a == *rr@.
92 extern void gf_div(mp
**/
*qq*/
, mp
**/
*rr*/
, mp */
*a*/
, mp */
*b*/
);
96 * Arguments: @mp *d@ = fake destination
100 * Returns: Result, %$a^e$%.
103 extern mp
*gf_exp(mp */
*d*/
, mp */
*a*/
, mp */
*e*/
);
105 /* --- @gf_irreduciblep@ --- *
107 * Arguments: @mp *f@ = a polynomial
109 * Returns: Nonzero if the polynomial is irreducible; otherwise zero.
112 extern int gf_irreduciblep(mp */
*f*/
);
114 /* --- @gf_gcd@ --- *
116 * Arguments: @mp **gcd, **xx, **yy@ = where to write the results
117 * @mp *a, *b@ = sources (must be nonzero)
122 * Use: Calculates @gcd(a, b)@, and two numbers @x@ and @y@ such that
123 * @ax + by = gcd(a, b)@. This is useful for computing modular
127 extern void gf_gcd(mp
**/
*gcd*/
, mp
**/
*xx*/
, mp
**/
*yy*/
,
128 mp */
*a*/
, mp */
*b*/
);
130 /* -- @gf_modinv@ --- *
132 * Arguments: @mp *d@ = destination
136 * Returns: The inverse %$x^{-1} \bmod p$%.
138 * Use: Computes a modular inverse, the catch being that the
139 * arguments and results are binary polynomials. An assertion
140 * fails if %$p$% has no inverse.
143 extern mp
*gf_modinv(mp */
*d*/
, mp */
*x*/
, mp */
*p*/
);
145 /*----- That's all, folks -------------------------------------------------*/