Commit | Line | Data |
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0f3faccd | 1 | /* -*-c-*- |
0f3faccd | 2 | * |
3 | * Raw formatting of elliptic curve points | |
4 | * | |
5 | * (c) 2004 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
0f3faccd | 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 | * |
0f3faccd | 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 | * |
0f3faccd | 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 | ||
0f3faccd | 28 | #ifndef CATACOMB_EC_RAW_H |
29 | #define CATACOMB_EC_RAW_H | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | /*----- Header files ------------------------------------------------------*/ | |
36 | ||
37 | #ifndef CATACOMB_BUF_H | |
38 | # include "buf.h" | |
39 | #endif | |
40 | ||
41 | #ifndef CATACOMB_EC_H | |
42 | # include "ec.h" | |
43 | #endif | |
44 | ||
45 | /*----- Data formatting ---------------------------------------------------*/ | |
46 | ||
6775a491 MW |
47 | /* EC2OSP/OS2ECP bit mask. */ |
48 | #define EC_YBIT 1u /* The compressed @y@-coordinate */ | |
49 | #define EC_XONLY 1u /* The @y@-coordinate is absent */ | |
50 | #define EC_CMPR 2u /* Compressed @y@-coordinate */ | |
51 | #define EC_LSB 2u /* Use `lsb' compression */ | |
52 | #define EC_EXPLY 4u /* Explicit @y@-coordinate */ | |
53 | #define EC_SORT 8u /* Use `sort' rather than `lsb' */ | |
54 | ||
55 | /* --- @ec_ec2osp@ --- * | |
56 | * | |
57 | * Arguments: @ec_curve *c@ = elliptic curve | |
58 | * @unsigned f@ = format flags for output | |
59 | * @buf *b@ = pointer to a buffer | |
60 | * @const ec *p@ = an elliptic curve point | |
61 | * | |
62 | * Returns: Zero on success, nonzero on failure. | |
63 | * | |
64 | * Use: Puts an elliptic curve point to the given buffer using the | |
65 | * standard uncompressed format described in P1363 and SEC1. | |
66 | * This requires at most @1 + 2 * c->f->noctets@ space in the | |
67 | * buffer. | |
68 | * | |
69 | * Point compression features are determined by @f@ as follows. | |
70 | * If @EC_CMPR@ is set then point compression is performed and a | |
71 | * compressed form of the %$y$%-coordinate is contained in the | |
72 | * first output byte; if @EC_SORT@ is set then P1363a `SORT' | |
73 | * compression is used, otherwise LSB compression. If | |
74 | * @EC_EXPLY@ is set, then an explicit %$y$%-coordinate is | |
75 | * output in full. Otherwise the %$y$%-coordinate is | |
76 | * suppressed. | |
d5d30579 MW |
77 | * |
78 | * Returns failure (@-1@) if the flags are invalid, or if there | |
79 | * isn't enough space in the output buffer. | |
6775a491 MW |
80 | */ |
81 | ||
82 | extern int ec_ec2osp(ec_curve */*c*/, unsigned /*f*/, | |
83 | buf */*b*/, const ec */*p*/); | |
84 | ||
85 | /* --- @ec_os2ecp@ --- * | |
86 | * | |
87 | * Arguments: @ec_curve *c = elliptic curve | |
88 | * @unsigned f@ = format flags for input | |
89 | * @buf *b@ = pointer to a buffer | |
90 | * @ec *d@ = an elliptic curve point | |
91 | * | |
92 | * Returns: Zero on success, nonzero on failure. | |
93 | * | |
94 | * Use: Reads an elliptic curve point from the given buffer using the | |
95 | * standard uncompressed format described in P1363 and SEC1. | |
96 | * | |
97 | * Point compression features are determined by @f@ as follows. | |
98 | * If @EC_LSB@ is set, then accept an LSB-compressed %$y$%- | |
99 | * coordinate; if @EC_SORT@ is set, then accept a SORT- | |
100 | * compressed %$y$%-coordinate; if @EC_EXPLY@ is set, then | |
101 | * accept an explicit %$y$%-coordinate; if @EC_XONLY@ is set | |
102 | * then accept a bare %$x$%-coordinate (a correct | |
103 | * %$y$%-coordinate is chosen arbitrarily). Hybrid forms are | |
104 | * acceptable, and the input is checked to verify that the | |
105 | * redundant representations are consistent. If no flags are | |
106 | * set in @f@, then no input (other than the point at infinity) | |
107 | * will be acceptable. | |
108 | */ | |
109 | ||
110 | extern int ec_os2ecp(ec_curve */*c*/, unsigned /*f*/, buf */*b*/, ec */*d*/); | |
111 | ||
0f3faccd | 112 | /* --- @ec_putraw@ --- * |
113 | * | |
114 | * Arguments: @ec_curve *c@ = elliptic curve | |
115 | * @buf *b@ = pointer to a buffer | |
116 | * @const ec *p@ = an elliptic curve point | |
117 | * | |
118 | * Returns: Zero on success, nonzero on failure. | |
119 | * | |
120 | * Use: Puts an elliptic curve point to the given buffer using the | |
121 | * standard uncompressed format described in P1383 and SEC1. | |
122 | * We don't do point compression. | |
123 | */ | |
124 | ||
125 | extern int ec_putraw(ec_curve */*c*/, buf */*b*/, const ec */*p*/); | |
126 | ||
127 | /* --- @ec_getraw@ --- * | |
128 | * | |
129 | * Arguments: @ec_curve *c@ = elliptic curve | |
130 | * @buf *b@ = pointer to a buffer | |
131 | * @ec *d@ = an elliptic curve point | |
132 | * | |
133 | * Returns: Zero on success, nonzero on failure. | |
134 | * | |
135 | * Use: Reads an elliptic curve point from the given buffer using the | |
136 | * standard uncompressed format described in P1383 and SEC1. | |
137 | * We don't do point compression. | |
138 | */ | |
139 | ||
140 | extern int ec_getraw(ec_curve */*c*/, buf */*b*/, ec */*d*/); | |
141 | ||
142 | /*----- That's all, folks -------------------------------------------------*/ | |
143 | ||
144 | #ifdef __cplusplus | |
145 | } | |
146 | #endif | |
147 | ||
148 | #endif |