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ceb3f0c0 | 1 | /* -*-c-*- |
2 | * | |
b817bfc6 | 3 | * $Id: gfreduce.h,v 1.3 2004/04/08 01:36:15 mdw Exp $ |
ceb3f0c0 | 4 | * |
5 | * Reduction modulo sparse binary polynomials | |
6 | * | |
7 | * (c) 2004 Straylight/Edgeware | |
8 | */ | |
9 | ||
45c0fd36 | 10 | /*----- Licensing notice --------------------------------------------------* |
ceb3f0c0 | 11 | * |
12 | * This file is part of Catacomb. | |
13 | * | |
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. | |
45c0fd36 | 18 | * |
ceb3f0c0 | 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. | |
45c0fd36 | 23 | * |
ceb3f0c0 | 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, | |
27 | * MA 02111-1307, USA. | |
28 | */ | |
29 | ||
ceb3f0c0 | 30 | #ifndef CATACOMB_GFREDUCE_H |
31 | #define CATACOMB_GFREDUCE_H | |
32 | ||
33 | #ifdef __cplusplus | |
34 | extern "C" { | |
35 | #endif | |
36 | ||
37 | /*----- Header files ------------------------------------------------------*/ | |
38 | ||
39 | #ifndef CATACOMB_GF_H | |
40 | # include "gf.h" | |
41 | #endif | |
42 | ||
43 | /*----- Data structures ---------------------------------------------------*/ | |
44 | ||
45 | typedef struct gfreduce_instr { | |
46 | unsigned op; /* Instruction opcode */ | |
47 | size_t arg; /* Immediate argument */ | |
48 | } gfreduce_instr; | |
49 | ||
50 | enum { | |
51 | GFRI_LOAD, /* Load @p[arg]@ */ | |
52 | GFRI_LSL, /* XOR with @w << arg@ */ | |
53 | GFRI_LSR, /* XOR with @w >> arg@ */ | |
54 | GFRI_STORE, /* Store @p[arg]@ */ | |
55 | GFRI_MAX | |
56 | }; | |
57 | ||
58 | typedef struct gfreduce { | |
59 | size_t lim; /* Word of degree bit */ | |
60 | mpw mask; /* Mask for degree word */ | |
61 | mp *p; /* Copy of the polynomial */ | |
62 | size_t in; /* Number of instruction words */ | |
63 | gfreduce_instr *iv, *liv; /* Vector of instructions */ | |
64 | } gfreduce; | |
65 | ||
66 | /*----- Functions provided ------------------------------------------------*/ | |
67 | ||
68 | /* --- @gfreduce_create@ --- * | |
69 | * | |
70 | * Arguments: @gfreduce *r@ = structure to fill in | |
71 | * @mp *x@ = a (hopefully sparse) polynomial | |
72 | * | |
73 | * Returns: --- | |
74 | * | |
75 | * Use: Initializes a context structure for reduction. | |
76 | */ | |
77 | ||
78 | extern void gfreduce_create(gfreduce */*r*/, mp */*p*/); | |
79 | ||
80 | /* --- @gfreduce_destroy@ --- * | |
81 | * | |
82 | * Arguments: @gfreduce *r@ = structure to free | |
83 | * | |
84 | * Returns: --- | |
85 | * | |
86 | * Use: Reclaims the resources from a reduction context. | |
87 | */ | |
88 | ||
89 | extern void gfreduce_destroy(gfreduce */*r*/); | |
90 | ||
91 | /* --- @gfreduce_dump@ --- * | |
92 | * | |
93 | * Arguments: @gfreduce *r@ = structure to dump | |
94 | * @FILE *fp@ = file to dump on | |
95 | * | |
96 | * Returns: --- | |
97 | * | |
98 | * Use: Dumps a reduction context. | |
99 | */ | |
100 | ||
101 | extern void gfreduce_dump(gfreduce */*r*/, FILE */*fp*/); | |
102 | ||
103 | /* --- @gfreduce_do@ --- * | |
104 | * | |
105 | * Arguments: @gfreduce *r@ = reduction context | |
106 | * @mp *d@ = destination | |
107 | * @mp *x@ = source | |
108 | * | |
109 | * Returns: Destination, @x@ reduced modulo the reduction poly. | |
110 | */ | |
111 | ||
112 | extern mp *gfreduce_do(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
113 | ||
114 | /* --- @gfreduce_sqrt@ --- * | |
115 | * | |
116 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
117 | * @mp *d@ = destination | |
118 | * @mp *x@ = some polynomial | |
119 | * | |
120 | * Returns: The square root of @x@ modulo @r->p@, or null. | |
121 | */ | |
122 | ||
123 | extern mp *gfreduce_sqrt(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
124 | ||
125 | /* --- @gfreduce_trace@ --- * | |
126 | * | |
127 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
128 | * @mp *x@ = some polynomial | |
129 | * | |
130 | * Returns: The trace of @x@. (%$\Tr(x)=x + x^2 + \cdots + x^{2^{m-1}}$% | |
131 | * if %$x \in \gf{2^m}$%). | |
132 | */ | |
133 | ||
134 | extern int gfreduce_trace(gfreduce */*r*/, mp */*x*/); | |
135 | ||
136 | /* --- @gfreduce_halftrace@ --- * | |
137 | * | |
138 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
139 | * @mp *d@ = destination | |
140 | * @mp *x@ = some polynomial | |
141 | * | |
142 | * Returns: The half-trace of @x@. | |
143 | * (%$\HfTr(x)= x + x^{2^2} + \cdots + x^{2^{m-1}}$% | |
144 | * if %$x \in \gf{2^m}$% with %$m$% odd). | |
145 | */ | |
146 | ||
147 | extern mp *gfreduce_halftrace(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
148 | ||
149 | /* --- @gfreduce_quadsolve@ --- * | |
150 | * | |
151 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
152 | * @mp *d@ = destination | |
153 | * @mp *x@ = some polynomial | |
154 | * | |
155 | * Returns: A polynomial @y@ such that %$y^2 + y = x$%, or null. | |
156 | */ | |
157 | ||
158 | extern mp *gfreduce_quadsolve(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
159 | ||
160 | /* --- @gfreduce_exp@ --- * | |
161 | * | |
162 | * Arguments: @gfreduce *gr@ = pointer to reduction context | |
45c0fd36 MW |
163 | * @mp *d@ = fake destination |
164 | * @mp *a@ = base | |
165 | * @mp *e@ = exponent | |
ceb3f0c0 | 166 | * |
45c0fd36 | 167 | * Returns: Result, %$a^e \bmod m$%. |
ceb3f0c0 | 168 | */ |
169 | ||
170 | extern mp *gfreduce_exp(gfreduce */*gr*/, mp */*d*/, mp */*a*/, mp */*e*/); | |
171 | ||
172 | /*----- That's all, folks -------------------------------------------------*/ | |
173 | ||
174 | #ifdef __cplusplus | |
175 | } | |
176 | #endif | |
177 | ||
178 | #endif |