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ceb3f0c0 | 1 | /* -*-c-*- |
2 | * | |
ceb3f0c0 | 3 | * Reduction modulo sparse binary polynomials |
4 | * | |
5 | * (c) 2004 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
ceb3f0c0 | 9 | * |
10 | * This file is part of Catacomb. | |
11 | * | |
12 | * Catacomb is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU Library General Public License as | |
14 | * published by the Free Software Foundation; either version 2 of the | |
15 | * License, or (at your option) any later version. | |
45c0fd36 | 16 | * |
ceb3f0c0 | 17 | * Catacomb is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU Library General Public License for more details. | |
45c0fd36 | 21 | * |
ceb3f0c0 | 22 | * You should have received a copy of the GNU Library General Public |
23 | * License along with Catacomb; if not, write to the Free | |
24 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
25 | * MA 02111-1307, USA. | |
26 | */ | |
27 | ||
ceb3f0c0 | 28 | #ifndef CATACOMB_GFREDUCE_H |
29 | #define CATACOMB_GFREDUCE_H | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | /*----- Header files ------------------------------------------------------*/ | |
36 | ||
37 | #ifndef CATACOMB_GF_H | |
38 | # include "gf.h" | |
39 | #endif | |
40 | ||
41 | /*----- Data structures ---------------------------------------------------*/ | |
42 | ||
43 | typedef struct gfreduce_instr { | |
44 | unsigned op; /* Instruction opcode */ | |
45 | size_t arg; /* Immediate argument */ | |
46 | } gfreduce_instr; | |
47 | ||
48 | enum { | |
49 | GFRI_LOAD, /* Load @p[arg]@ */ | |
50 | GFRI_LSL, /* XOR with @w << arg@ */ | |
51 | GFRI_LSR, /* XOR with @w >> arg@ */ | |
52 | GFRI_STORE, /* Store @p[arg]@ */ | |
53 | GFRI_MAX | |
54 | }; | |
55 | ||
56 | typedef struct gfreduce { | |
57 | size_t lim; /* Word of degree bit */ | |
58 | mpw mask; /* Mask for degree word */ | |
59 | mp *p; /* Copy of the polynomial */ | |
60 | size_t in; /* Number of instruction words */ | |
61 | gfreduce_instr *iv, *liv; /* Vector of instructions */ | |
62 | } gfreduce; | |
63 | ||
64 | /*----- Functions provided ------------------------------------------------*/ | |
65 | ||
66 | /* --- @gfreduce_create@ --- * | |
67 | * | |
68 | * Arguments: @gfreduce *r@ = structure to fill in | |
69 | * @mp *x@ = a (hopefully sparse) polynomial | |
70 | * | |
71 | * Returns: --- | |
72 | * | |
73 | * Use: Initializes a context structure for reduction. | |
74 | */ | |
75 | ||
76 | extern void gfreduce_create(gfreduce */*r*/, mp */*p*/); | |
77 | ||
78 | /* --- @gfreduce_destroy@ --- * | |
79 | * | |
80 | * Arguments: @gfreduce *r@ = structure to free | |
81 | * | |
82 | * Returns: --- | |
83 | * | |
84 | * Use: Reclaims the resources from a reduction context. | |
85 | */ | |
86 | ||
87 | extern void gfreduce_destroy(gfreduce */*r*/); | |
88 | ||
89 | /* --- @gfreduce_dump@ --- * | |
90 | * | |
91 | * Arguments: @gfreduce *r@ = structure to dump | |
92 | * @FILE *fp@ = file to dump on | |
93 | * | |
94 | * Returns: --- | |
95 | * | |
96 | * Use: Dumps a reduction context. | |
97 | */ | |
98 | ||
99 | extern void gfreduce_dump(gfreduce */*r*/, FILE */*fp*/); | |
100 | ||
101 | /* --- @gfreduce_do@ --- * | |
102 | * | |
103 | * Arguments: @gfreduce *r@ = reduction context | |
104 | * @mp *d@ = destination | |
105 | * @mp *x@ = source | |
106 | * | |
107 | * Returns: Destination, @x@ reduced modulo the reduction poly. | |
108 | */ | |
109 | ||
110 | extern mp *gfreduce_do(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
111 | ||
112 | /* --- @gfreduce_sqrt@ --- * | |
113 | * | |
114 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
115 | * @mp *d@ = destination | |
116 | * @mp *x@ = some polynomial | |
117 | * | |
118 | * Returns: The square root of @x@ modulo @r->p@, or null. | |
119 | */ | |
120 | ||
121 | extern mp *gfreduce_sqrt(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
122 | ||
123 | /* --- @gfreduce_trace@ --- * | |
124 | * | |
125 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
126 | * @mp *x@ = some polynomial | |
127 | * | |
128 | * Returns: The trace of @x@. (%$\Tr(x)=x + x^2 + \cdots + x^{2^{m-1}}$% | |
129 | * if %$x \in \gf{2^m}$%). | |
130 | */ | |
131 | ||
132 | extern int gfreduce_trace(gfreduce */*r*/, mp */*x*/); | |
133 | ||
134 | /* --- @gfreduce_halftrace@ --- * | |
135 | * | |
136 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
137 | * @mp *d@ = destination | |
138 | * @mp *x@ = some polynomial | |
139 | * | |
140 | * Returns: The half-trace of @x@. | |
141 | * (%$\HfTr(x)= x + x^{2^2} + \cdots + x^{2^{m-1}}$% | |
142 | * if %$x \in \gf{2^m}$% with %$m$% odd). | |
143 | */ | |
144 | ||
145 | extern mp *gfreduce_halftrace(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
146 | ||
147 | /* --- @gfreduce_quadsolve@ --- * | |
148 | * | |
149 | * Arguments: @gfreduce *r@ = pointer to reduction context | |
150 | * @mp *d@ = destination | |
151 | * @mp *x@ = some polynomial | |
152 | * | |
153 | * Returns: A polynomial @y@ such that %$y^2 + y = x$%, or null. | |
154 | */ | |
155 | ||
156 | extern mp *gfreduce_quadsolve(gfreduce */*r*/, mp */*d*/, mp */*x*/); | |
157 | ||
158 | /* --- @gfreduce_exp@ --- * | |
159 | * | |
160 | * Arguments: @gfreduce *gr@ = pointer to reduction context | |
45c0fd36 MW |
161 | * @mp *d@ = fake destination |
162 | * @mp *a@ = base | |
163 | * @mp *e@ = exponent | |
ceb3f0c0 | 164 | * |
45c0fd36 | 165 | * Returns: Result, %$a^e \bmod m$%. |
ceb3f0c0 | 166 | */ |
167 | ||
168 | extern mp *gfreduce_exp(gfreduce */*gr*/, mp */*d*/, mp */*a*/, mp */*e*/); | |
169 | ||
170 | /*----- That's all, folks -------------------------------------------------*/ | |
171 | ||
172 | #ifdef __cplusplus | |
173 | } | |
174 | #endif | |
175 | ||
176 | #endif |