Commit | Line | Data |
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8dd8c294 | 1 | /* -*-c-*- |
8dd8c294 | 2 | * |
3 | * The Serpent block cipher | |
4 | * | |
5 | * (c) 2000 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
8dd8c294 | 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 | * |
8dd8c294 | 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 | * |
8dd8c294 | 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 | ||
8dd8c294 | 28 | /*----- Header files ------------------------------------------------------*/ |
29 | ||
30 | #include <assert.h> | |
31 | #include <stdio.h> | |
32 | ||
33 | #include <mLib/bits.h> | |
34 | ||
35 | #include "blkc.h" | |
36 | #include "gcipher.h" | |
37 | #include "serpent.h" | |
38 | #include "serpent-sbox.h" | |
39 | ||
40 | /*----- Global variables --------------------------------------------------*/ | |
41 | ||
42 | const octet serpent_keysz[] = { KSZ_RANGE, SERPENT_KEYSZ, 0, 32, 1 }; | |
43 | ||
44 | /*----- Main code ---------------------------------------------------------*/ | |
45 | ||
46 | /* --- @serpent_init@ --- * | |
47 | * | |
48 | * Arguments: @serpent_ctx *k@ = pointer to context block to initialize | |
49 | * @const void *buf@ = pointer to input buffer | |
50 | * @size_t sz@ = size of input buffer | |
51 | * | |
52 | * Returns: --- | |
53 | * | |
54 | * Use: Initializes a Serpent context. The key may be any length of | |
55 | * up to 32 bytes (256 bits). | |
56 | */ | |
57 | ||
58 | void serpent_init(serpent_ctx *k, const void *buf, size_t sz) | |
59 | { | |
60 | uint32 a; | |
61 | unsigned b; | |
62 | const octet *p, *q; | |
63 | size_t i; | |
64 | uint32 pk[8 + 132]; | |
65 | ||
66 | KSZ_ASSERT(serpent, sz); | |
67 | ||
68 | /* --- Read the key into the buffer --- */ | |
69 | ||
70 | if (sz > 32) | |
71 | sz = 32; | |
72 | i = 0; p = buf; q = p + sz; | |
73 | a = 0; b = 0; | |
74 | while (p < q) { | |
75 | a |= (uint32)*p++ << b; | |
76 | b += 8; | |
77 | if (b == 32) { | |
78 | pk[i++] = a; | |
79 | a = 0; b = 0; | |
80 | } | |
81 | } | |
82 | ||
83 | /* --- Pad short keys --- */ | |
84 | ||
85 | if (i < 8) { | |
86 | a |= 0x01 << b; | |
87 | b += 8; | |
88 | pk[i++] = a; | |
89 | for (; i < 8; i++) | |
90 | pk[i] = 0; | |
91 | } | |
92 | ||
93 | /* --- Expand the prekeys to fill the buffer --- */ | |
94 | ||
95 | for (i = 8; i < 8 + 132; i++) { | |
96 | uint32 x = (pk[i - 8] ^ pk[i - 5] ^ pk[i - 3] ^ pk[i - 1] ^ | |
97 | (i - 8) ^ 0x9e3779b9); | |
98 | k->k[i - 8] = pk[i] = ROL32(x, 11); | |
99 | } | |
100 | ||
101 | /* --- Now substitute everything --- */ | |
102 | ||
103 | i = 0; | |
104 | goto midway; | |
105 | while (i < 132) { | |
106 | #define KSUB(r) do { \ | |
107 | uint32 a, b, c, d; \ | |
108 | a = k->k[i]; b = k->k[i + 1]; c = k->k[i + 2]; d = k->k[i + 3]; \ | |
109 | S##r(a, b, c, d); \ | |
110 | k->k[i] = a; k->k[i + 1] = b; k->k[i + 2] = c; k->k[i + 3] = d; \ | |
111 | i += 4; \ | |
112 | } while (0) | |
113 | KSUB(2); KSUB(1); KSUB(0); KSUB(7); | |
114 | KSUB(6); KSUB(5); KSUB(4); | |
115 | midway: | |
116 | KSUB(3); | |
117 | #undef KSUB | |
118 | } | |
119 | } | |
120 | ||
121 | /* --- @serpent_eblk@, @serpent_dblk@ --- * | |
122 | * | |
123 | * Arguments: @const serpent_ctx *k@ = pointer to key context | |
124 | * @const uint32 s[4]@ = pointer to source block | |
125 | * @uint32 d[4]@ = pointer to destination block | |
126 | * | |
127 | * Returns: --- | |
128 | * | |
129 | * Use: Low-level block encryption. | |
130 | */ | |
131 | ||
132 | #define EROUND(a, b, c, d, r, k) do { \ | |
133 | a ^= *k++; b ^= *k++; c ^= *k++; d ^= *k++; \ | |
134 | S##r(a, b, c, d); \ | |
135 | a = ROL32(a, 13); c = ROL32(c, 3); b ^= a ^ c; d ^= c ^ (a << 3); \ | |
45c0fd36 MW |
136 | b = ROL32(b, 1); d = ROL32(d, 7); a ^= b ^ d; c ^= d ^ (b << 7); \ |
137 | a = ROL32(a, 5); c = ROL32(c, 22); \ | |
8dd8c294 | 138 | } while (0) |
139 | ||
140 | #define DROUND(a, b, c, d, r, k) do { \ | |
141 | IS##r(a, b, c, d); \ | |
142 | d ^= *--k; c ^= *--k; b ^= *--k; a ^= *--k; \ | |
45c0fd36 MW |
143 | a = ROR32(a, 5); c = ROR32(c, 22); a ^= b ^ d; c ^= d ^ (b << 7); \ |
144 | b = ROR32(b, 1); d = ROR32(d, 7); b ^= a ^ c; d ^= c ^ (a << 3); \ | |
8dd8c294 | 145 | a = ROR32(a, 13); c = ROR32(c, 3); \ |
146 | } while (0) | |
147 | ||
148 | void serpent_eblk(const serpent_ctx *k, const uint32 *s, uint32 *d) | |
149 | { | |
150 | uint32 aa = s[0], bb = s[1], cc = s[2], dd = s[3]; | |
151 | const uint32 *kk = k->k; | |
152 | ||
153 | EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk); | |
154 | EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk); | |
155 | EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk); | |
156 | EROUND(aa, bb, cc, dd, 6, kk); EROUND(aa, bb, cc, dd, 7, kk); | |
157 | ||
158 | EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk); | |
159 | EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk); | |
160 | EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk); | |
161 | EROUND(aa, bb, cc, dd, 6, kk); EROUND(aa, bb, cc, dd, 7, kk); | |
162 | ||
163 | EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk); | |
164 | EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk); | |
165 | EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk); | |
166 | EROUND(aa, bb, cc, dd, 6, kk); EROUND(aa, bb, cc, dd, 7, kk); | |
167 | ||
168 | EROUND(aa, bb, cc, dd, 0, kk); EROUND(aa, bb, cc, dd, 1, kk); | |
169 | EROUND(aa, bb, cc, dd, 2, kk); EROUND(aa, bb, cc, dd, 3, kk); | |
170 | EROUND(aa, bb, cc, dd, 4, kk); EROUND(aa, bb, cc, dd, 5, kk); | |
171 | EROUND(aa, bb, cc, dd, 6, kk); | |
172 | ||
173 | aa ^= *kk++; bb ^= *kk++; cc ^= *kk++; dd ^= *kk++; | |
174 | S7(aa, bb, cc, dd); | |
175 | aa ^= *kk++; bb ^= *kk++; cc ^= *kk++; dd ^= *kk++; | |
176 | d[0] = aa; d[1] = bb; d[2] = cc; d[3] = dd; | |
177 | } | |
178 | ||
179 | void serpent_dblk(const serpent_ctx *k, const uint32 *s, uint32 *d) | |
180 | { | |
181 | uint32 aa = s[0], bb = s[1], cc = s[2], dd = s[3]; | |
182 | const uint32 *kk = k->k + 132; | |
183 | ||
184 | dd ^= *--kk; cc ^= *--kk; bb ^= *--kk; aa ^= *--kk; | |
185 | ||
186 | DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk); | |
187 | DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk); | |
188 | DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk); | |
189 | DROUND(aa, bb, cc, dd, 1, kk); DROUND(aa, bb, cc, dd, 0, kk); | |
190 | ||
191 | DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk); | |
192 | DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk); | |
193 | DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk); | |
194 | DROUND(aa, bb, cc, dd, 1, kk); DROUND(aa, bb, cc, dd, 0, kk); | |
195 | ||
196 | DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk); | |
197 | DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk); | |
198 | DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk); | |
199 | DROUND(aa, bb, cc, dd, 1, kk); DROUND(aa, bb, cc, dd, 0, kk); | |
200 | ||
201 | DROUND(aa, bb, cc, dd, 7, kk); DROUND(aa, bb, cc, dd, 6, kk); | |
202 | DROUND(aa, bb, cc, dd, 5, kk); DROUND(aa, bb, cc, dd, 4, kk); | |
203 | DROUND(aa, bb, cc, dd, 3, kk); DROUND(aa, bb, cc, dd, 2, kk); | |
204 | DROUND(aa, bb, cc, dd, 1, kk); | |
205 | ||
206 | IS0(aa, bb, cc, dd); | |
207 | dd ^= *--kk; cc ^= *--kk; bb ^= *--kk; aa ^= *--kk; | |
208 | d[0] = aa; d[1] = bb; d[2] = cc; d[3] = dd; | |
209 | } | |
210 | ||
211 | BLKC_TEST(SERPENT, serpent) | |
212 | ||
213 | /*----- That's all, folks -------------------------------------------------*/ |