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643eb1bb MW |
1 | /* -*-c-*- |
2 | * | |
3 | * The X448 key-agreement algorithm | |
4 | * | |
5 | * (c) 2017 Straylight/Edgeware | |
6 | */ | |
7 | ||
8 | /*----- Licensing notice --------------------------------------------------* | |
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. | |
16 | * | |
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. | |
21 | * | |
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 | ||
28 | /*----- Header files ------------------------------------------------------*/ | |
29 | ||
30 | #include <mLib/bits.h> | |
31 | ||
32 | #include "montladder.h" | |
33 | #include "fgoldi.h" | |
34 | #include "x448.h" | |
35 | ||
36 | /*----- Important constants -----------------------------------------------*/ | |
37 | ||
38 | const octet x448_base[56] = { 5, 0, /* ... */ }; | |
39 | ||
40 | #define A0 39081 | |
41 | ||
42 | /*----- Key fetching ------------------------------------------------------*/ | |
43 | ||
44 | const key_fetchdef x448_pubfetch[] = { | |
45 | { "pub", offsetof(x448_pub, pub), KENC_BINARY, 0 }, | |
46 | { 0, 0, 0, 0 } | |
47 | }; | |
48 | ||
49 | static const key_fetchdef priv[] = { | |
50 | { "priv", offsetof(x448_priv, priv), KENC_BINARY, 0 }, | |
51 | { 0, 0, 0, 0 } | |
52 | }; | |
53 | ||
54 | const key_fetchdef x448_privfetch[] = { | |
55 | { "pub", offsetof(x448_priv, pub), KENC_BINARY, 0 }, | |
56 | { "private", 0, KENC_STRUCT, priv }, | |
57 | { 0, 0, 0, 0 } | |
58 | }; | |
59 | ||
60 | /*----- Main code ---------------------------------------------------------*/ | |
61 | ||
62 | /* --- @x448@ --- * | |
63 | * | |
64 | * Arguments: @octet zz[X448_OUTSZ]@ = where to put the result | |
65 | * @const octet k[X448_KEYSZ]@ = pointer to private key | |
66 | * @const octet qx[X448_PUBSZ]@ = pointer to public value | |
67 | * | |
68 | * Returns: --- | |
69 | * | |
70 | * Use: Calculates X448 of @k@ and @qx@. | |
71 | */ | |
72 | ||
73 | void x448(octet zz[X448_OUTSZ], | |
74 | const octet k[X448_KEYSZ], | |
75 | const octet qx[X448_PUBSZ]) | |
76 | { | |
77 | uint32 kw[14]; | |
78 | fgoldi x1; | |
79 | unsigned i; | |
80 | ||
81 | /* Load and clamp the key. The low bits are cleared to kill the small | |
82 | * subgroups on the curve and its twist, and a high bit is set to guard | |
83 | * against careless implementations, though this isn't one of those. | |
84 | */ | |
85 | for (i = 0; i < 14; i++) kw[i] = LOAD32_L(k + 4*i); | |
86 | kw[0] &= 0xfffffffc; kw[13] |= 0x80000000; | |
87 | ||
88 | /* And run the ladder. */ | |
89 | fgoldi_load(&x1, qx); | |
90 | #define MULA0(z, x) do { fgoldi_mulconst((z), (x), A0); } while (0) | |
91 | MONT_LADDER(fgoldi, MULA0, kw, 14, 32, &x1, &x1); | |
92 | #undef MULA0 | |
93 | fgoldi_store(zz, &x1); | |
94 | } | |
95 | ||
96 | /*----- Test rig ----------------------------------------------------------*/ | |
97 | ||
98 | #ifdef TEST_RIG | |
99 | ||
141c1284 | 100 | #include <mLib/macros.h> |
643eb1bb | 101 | #include <mLib/report.h> |
643eb1bb MW |
102 | #include <mLib/testrig.h> |
103 | ||
1aaccf40 MW |
104 | #include "ct.h" |
105 | ||
643eb1bb MW |
106 | static int vrf_x448(dstr dv[]) |
107 | { | |
108 | dstr dz = DSTR_INIT; | |
109 | int ok = 1; | |
110 | ||
1b59808c MW |
111 | if (dv[0].len != X448_KEYSZ) die(1, "bad key length"); |
112 | if (dv[1].len != X448_PUBSZ) die(1, "bad public length"); | |
113 | if (dv[2].len != X448_OUTSZ) die(1, "bad result length"); | |
643eb1bb | 114 | |
1aaccf40 | 115 | ct_poison(dv[0].buf, dv[0].len); |
1b59808c | 116 | dstr_ensure(&dz, X448_OUTSZ); dz.len = X448_OUTSZ; |
643eb1bb MW |
117 | x448((octet *)dz.buf, |
118 | (const octet *)dv[0].buf, | |
119 | (const octet *)dv[1].buf); | |
1aaccf40 | 120 | ct_remedy(dz.buf, dz.len); |
141c1284 | 121 | if (MEMCMP(dz.buf, !=, dv[2].buf, X448_OUTSZ)) { |
643eb1bb MW |
122 | ok = 0; |
123 | fprintf(stderr, "failed!"); | |
124 | fprintf(stderr, "\n\t k = "); type_hex.dump(&dv[0], stderr); | |
125 | fprintf(stderr, "\n\t p = "); type_hex.dump(&dv[1], stderr); | |
126 | fprintf(stderr, "\n\twant = "); type_hex.dump(&dv[2], stderr); | |
127 | fprintf(stderr, "\n\tcalc = "); type_hex.dump(&dz, stderr); | |
128 | fprintf(stderr, "\n"); | |
129 | } | |
130 | ||
131 | dstr_destroy(&dz); | |
132 | return (ok); | |
133 | } | |
134 | ||
135 | static int vrf_mct(dstr dv[]) | |
136 | { | |
1b59808c | 137 | octet b0[X448_OUTSZ], b1[X448_OUTSZ], *k = b0, *x = b1, *t; |
643eb1bb MW |
138 | unsigned long i, niter; |
139 | dstr d = DSTR_INIT; | |
140 | int ok = 1; | |
141 | ||
142 | if (dv[0].len != sizeof(b0)) { fprintf(stderr, "k len\n"); exit(2); } | |
143 | if (dv[1].len != sizeof(b1)) { fprintf(stderr, "x len\n"); exit(2); } | |
144 | if (dv[3].len != sizeof(b0)) { fprintf(stderr, "result len\n"); exit(2); } | |
145 | memcpy(b0, dv[0].buf, sizeof(b0)); | |
146 | memcpy(b1, dv[1].buf, sizeof(b1)); | |
147 | niter = *(unsigned long *)dv[2].buf; | |
1b59808c | 148 | dstr_ensure(&d, X448_OUTSZ); d.len = X448_OUTSZ; t = (octet *)d.buf; |
643eb1bb MW |
149 | |
150 | for (i = 0; i < niter; i++) { | |
151 | x448(x, k, x); | |
152 | t = x; x = k; k = t; | |
153 | } | |
154 | memcpy(d.buf, k, d.len); | |
155 | ||
141c1284 | 156 | if (MEMCMP(d.buf, !=, dv[3].buf, d.len)) { |
643eb1bb MW |
157 | ok = 0; |
158 | fprintf(stderr, "failed..."); | |
159 | fprintf(stderr, "\n\tinitial k = "); type_hex.dump(&dv[0], stderr); | |
160 | fprintf(stderr, "\n\tinitial x = "); type_hex.dump(&dv[1], stderr); | |
161 | fprintf(stderr, "\n\titerations = %lu", niter); | |
162 | fprintf(stderr, "\n\texpected = "); type_hex.dump(&dv[3], stderr); | |
163 | fprintf(stderr, "\n\tcalculated = "); type_hex.dump(&d, stderr); | |
164 | fputc('\n', stderr); | |
165 | } | |
166 | ||
167 | dstr_destroy(&d); | |
168 | return (ok); | |
169 | } | |
170 | ||
171 | static test_chunk tests[] = { | |
172 | { "x448", vrf_x448, { &type_hex, &type_hex, &type_hex } }, | |
173 | { "x448-mct", vrf_mct, | |
174 | { &type_hex, &type_hex, &type_ulong, &type_hex } }, | |
175 | { 0, 0, { 0 } } | |
176 | }; | |
177 | ||
178 | int main(int argc, char *argv[]) | |
179 | { | |
180 | test_run(argc, argv, tests, SRCDIR "/t/x448"); | |
181 | return (0); | |
182 | } | |
183 | ||
184 | #endif | |
185 | ||
186 | /*----- That's all, folks -------------------------------------------------*/ |