Commit | Line | Data |
---|---|---|
0bcb8184 MW |
1 | /* |
2 | * fgoldi.h: arithmetic modulo 2^448 - 2^224 - 1 | |
3 | */ | |
4 | /* | |
5 | * This file is Free Software. It has been modified to as part of its | |
6 | * incorporation into secnet. | |
7 | * | |
8 | * Copyright 2017 Mark Wooding | |
9 | * | |
10 | * You may redistribute this file and/or modify it under the terms of | |
11 | * the permissive licence shown below. | |
12 | * | |
13 | * You may redistribute secnet as a whole and/or modify it under the | |
14 | * terms of the GNU General Public License as published by the Free | |
15 | * Software Foundation; either version 3, or (at your option) any | |
16 | * later version. | |
17 | * | |
18 | * This program is distributed in the hope that it will be useful, | |
19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | * GNU General Public License for more details. | |
22 | * | |
23 | * You should have received a copy of the GNU General Public License | |
24 | * along with this program; if not, see | |
25 | * https://www.gnu.org/licenses/gpl.html. | |
26 | */ | |
27 | /* | |
28 | * Imported from Catacomb, and lightly modified for Secnet (2017-04-30): | |
29 | * | |
30 | * * Use `fake-mLib-bits.h' in place of the real <mLib/bits.h>. | |
31 | * | |
32 | * * Remove the 16/32-bit implementation, since C99 always has 64-bit | |
33 | * arithmetic. | |
34 | * | |
35 | * The file's original comment headers are preserved below. | |
36 | */ | |
b7a5ecfc MW |
37 | /* -*-c-*- |
38 | * | |
39 | * Arithmetic in the Goldilocks field GF(2^448 - 2^224 - 1) | |
40 | * | |
41 | * (c) 2017 Straylight/Edgeware | |
42 | */ | |
43 | ||
44 | /*----- Licensing notice --------------------------------------------------* | |
45 | * | |
46 | * This file is part of Catacomb. | |
47 | * | |
48 | * Catacomb is free software; you can redistribute it and/or modify | |
49 | * it under the terms of the GNU Library General Public License as | |
50 | * published by the Free Software Foundation; either version 2 of the | |
51 | * License, or (at your option) any later version. | |
52 | * | |
53 | * Catacomb is distributed in the hope that it will be useful, | |
54 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
55 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
56 | * GNU Library General Public License for more details. | |
57 | * | |
58 | * You should have received a copy of the GNU Library General Public | |
59 | * License along with Catacomb; if not, write to the Free | |
60 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
61 | * MA 02111-1307, USA. | |
62 | */ | |
63 | ||
64 | #ifndef CATACOMB_FGOLDI_H | |
65 | #define CATACOMB_FGOLDI_H | |
66 | ||
67 | #ifdef __cplusplus | |
68 | extern "C" { | |
69 | #endif | |
70 | ||
71 | /*----- Header files ------------------------------------------------------*/ | |
72 | ||
0bcb8184 | 73 | #include "fake-mLib-bits.h" |
b7a5ecfc MW |
74 | |
75 | #ifndef CATACOMB_QFARITH_H | |
76 | # include "qfarith.h" | |
77 | #endif | |
78 | ||
79 | /*----- Data structures ---------------------------------------------------*/ | |
80 | ||
81 | typedef union { | |
82 | int32 p28[16]; | |
b7a5ecfc MW |
83 | } fgoldi; |
84 | ||
85 | #if !defined(FGOLDI_IMPL) && defined(HAVE_INT64) | |
86 | # define FGOLDI_IMPL 28 | |
87 | #endif | |
88 | ||
89 | #ifndef FGOLDI_IMPL | |
90 | # define FGOLDI_IMPL 12 | |
91 | #endif | |
92 | ||
93 | /*----- Functions provided ------------------------------------------------*/ | |
94 | ||
95 | /* --- @fgoldi_load@ --- * | |
96 | * | |
97 | * Arguments: @fgoldi *z@ = where to store the result | |
98 | * @const octet xv[56]@ = source to read | |
99 | * | |
100 | * Returns: --- | |
101 | * | |
102 | * Use: Reads an element of %$\gf{2^{448} - 2^{224} - 19}$% in | |
103 | * external representation from @xv@ and stores it in @z@. | |
104 | * | |
105 | * External representation is little-endian base-256. Some | |
106 | * elements have multiple encodings, which are not produced by | |
107 | * correct software; use of noncanonical encodings is not an | |
108 | * error, and toleration of them is considered a performance | |
109 | * feature. | |
110 | */ | |
111 | ||
112 | extern void fgoldi_load(fgoldi */*z*/, const octet /*xv*/[56]); | |
113 | ||
114 | /* --- @fgoldi_store@ --- * | |
115 | * | |
116 | * Arguments: @octet zv[56]@ = where to write the result | |
117 | * @const fgoldi *x@ = the field element to write | |
118 | * | |
119 | * Returns: --- | |
120 | * | |
121 | * Use: Stores a field element in the given octet vector in external | |
122 | * representation. A canonical encoding is always stored. | |
123 | */ | |
124 | ||
125 | extern void fgoldi_store(octet /*zv*/[56], const fgoldi */*x*/); | |
126 | ||
127 | /* --- @fgoldi_set@ --- * | |
128 | * | |
129 | * Arguments: @fgoldi *z@ = where to write the result | |
130 | * @int a@ = a small-ish constant | |
131 | * | |
132 | * Returns: --- | |
133 | * | |
134 | * Use: Sets @z@ to equal @a@. | |
135 | */ | |
136 | ||
137 | extern void fgoldi_set(fgoldi */*x*/, int /*a*/); | |
138 | ||
139 | /* --- @fgoldi_add@ --- * | |
140 | * | |
141 | * Arguments: @fgoldi *z@ = where to put the result (may alias @x@ or @y@) | |
142 | * @const fgoldi *x, *y@ = two operands | |
143 | * | |
144 | * Returns: --- | |
145 | * | |
146 | * Use: Set @z@ to the sum %$x + y$%. | |
147 | */ | |
148 | ||
149 | extern void fgoldi_add(fgoldi */*z*/, | |
150 | const fgoldi */*x*/, const fgoldi */*y*/); | |
151 | ||
152 | /* --- @fgoldi_sub@ --- * | |
153 | * | |
154 | * Arguments: @fgoldi *z@ = where to put the result (may alias @x@ or @y@) | |
155 | * @const fgoldi *x, *y@ = two operands | |
156 | * | |
157 | * Returns: --- | |
158 | * | |
159 | * Use: Set @z@ to the difference %$x - y$%. | |
160 | */ | |
161 | ||
162 | extern void fgoldi_sub(fgoldi */*z*/, | |
163 | const fgoldi */*x*/, const fgoldi */*y*/); | |
164 | ||
165 | /* --- @fgoldi_condswap@ --- * | |
166 | * | |
167 | * Arguments: @fgoldi *x, *y@ = two operands | |
168 | * @uint32 m@ = a mask | |
169 | * | |
170 | * Returns: --- | |
171 | * | |
172 | * Use: If @m@ is zero, do nothing; if @m@ is all-bits-set, then | |
173 | * exchange @x@ and @y@. If @m@ has some other value, then | |
174 | * scramble @x@ and @y@ in an unhelpful way. | |
175 | */ | |
176 | ||
177 | extern void fgoldi_condswap(fgoldi */*x*/, fgoldi */*y*/, uint32 /*m*/); | |
178 | ||
179 | /* --- @fgoldi_mulconst@ --- * | |
180 | * | |
181 | * Arguments: @fgoldi *z@ = where to put the result (may alias @x@) | |
182 | * @const fgoldi *x@ = an operand | |
183 | * @long a@ = a small-ish constant; %$|a| < 2^{20}$%. | |
184 | * | |
185 | * Returns: --- | |
186 | * | |
187 | * Use: Set @z@ to the product %$a x$%. | |
188 | */ | |
189 | ||
190 | extern void fgoldi_mulconst(fgoldi */*z*/, const fgoldi */*x*/, long /*a*/); | |
191 | ||
192 | /* --- @fgoldi_mul@ --- * | |
193 | * | |
194 | * Arguments: @fgoldi *z@ = where to put the result (may alias @x@ or @y@) | |
195 | * @const fgoldi *x, *y@ = two operands | |
196 | * | |
197 | * Returns: --- | |
198 | * | |
199 | * Use: Set @z@ to the product %$x y$%. | |
200 | */ | |
201 | ||
202 | extern void fgoldi_mul(fgoldi */*z*/, | |
203 | const fgoldi */*x*/, const fgoldi */*y*/); | |
204 | ||
205 | /* --- @fgoldi_sqr@ --- * | |
206 | * | |
207 | * Arguments: @fgoldi *z@ = where to put the result (may alias @x@ or @y@) | |
208 | * @const fgoldi *x@ = an operand | |
209 | * | |
210 | * Returns: --- | |
211 | * | |
212 | * Use: Set @z@ to the square %$x^2$%. | |
213 | */ | |
214 | ||
215 | extern void fgoldi_sqr(fgoldi */*z*/, const fgoldi */*x*/); | |
216 | ||
217 | /* --- @fgoldi_inv@ --- * | |
218 | * | |
219 | * Arguments: @fgoldi *z@ = where to put the result (may alias @x@) | |
220 | * @const fgoldi *x@ = an operand | |
221 | * | |
222 | * Returns: --- | |
223 | * | |
224 | * Use: Stores in @z@ the multiplicative inverse %$x^{-1}$%. If | |
225 | * %$x = 0$% then @z@ is set to zero. This is considered a | |
226 | * feature. | |
227 | */ | |
228 | ||
229 | extern void fgoldi_inv(fgoldi */*z*/, const fgoldi */*x*/); | |
230 | ||
231 | /*----- That's all, folks -------------------------------------------------*/ | |
232 | ||
233 | #ifdef __cplusplus | |
234 | } | |
235 | #endif | |
236 | ||
237 | #endif |