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3bef8c14 | 1 | /* -*-c-*- |
2 | * | |
b817bfc6 | 3 | * $Id: mars.c,v 1.2 2004/04/08 01:36:15 mdw Exp $ |
3bef8c14 | 4 | * |
5 | * The MARS block cipher | |
6 | * | |
7 | * (c) 2001 Straylight/Edgeware | |
8 | */ | |
9 | ||
45c0fd36 | 10 | /*----- Licensing notice --------------------------------------------------* |
3bef8c14 | 11 | * |
12 | * This file is part of Catacomb. | |
13 | * | |
14 | * Catacomb is free software; you can redistribute it and/or modify | |
15 | * it under the terms of the GNU Library General Public License as | |
16 | * published by the Free Software Foundation; either version 2 of the | |
17 | * License, or (at your option) any later version. | |
45c0fd36 | 18 | * |
3bef8c14 | 19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | * GNU Library General Public License for more details. | |
45c0fd36 | 23 | * |
3bef8c14 | 24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free | |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, | |
27 | * MA 02111-1307, USA. | |
28 | */ | |
29 | ||
3bef8c14 | 30 | /*----- Header files ------------------------------------------------------*/ |
31 | ||
32 | #include <assert.h> | |
33 | #include <stdio.h> | |
34 | ||
35 | #include <mLib/bits.h> | |
36 | ||
37 | #include "blkc.h" | |
38 | #include "gcipher.h" | |
39 | #include "mars.h" | |
40 | #include "mars-tab.h" | |
41 | #include "paranoia.h" | |
42 | ||
43 | /*----- Global variables --------------------------------------------------*/ | |
44 | ||
45 | const octet mars_keysz[] = { KSZ_RANGE, MARS_KEYSZ, 0, 56, 4 }; | |
46 | ||
47 | /*----- Useful tables -----------------------------------------------------*/ | |
48 | ||
49 | static const uint32 s[512] = MARS_S; | |
45c0fd36 | 50 | #define s0 (s + 0) |
3bef8c14 | 51 | #define s1 (s + 256) |
52 | #define bb (s + 265) | |
53 | ||
54 | /*----- Main code ---------------------------------------------------------*/ | |
55 | ||
56 | /* --- @mars_init@ --- * | |
57 | * | |
58 | * Arguments: @mars_ctx *k@ = pointer to key block to fill in | |
59 | * @const void *buf@ = pointer to buffer of key material | |
60 | * @size_t sz@ = size of key material | |
61 | * | |
62 | * Returns: --- | |
63 | * | |
64 | * Use: Initializes a MARS key buffer. MARS accepts key sizes | |
65 | * between 128 and 448 bits which are a multiple of 32 bits. | |
66 | */ | |
67 | ||
68 | void mars_init(mars_ctx *k, const void *buf, size_t sz) | |
69 | { | |
70 | uint32 t[15]; | |
71 | uint32 *kk = k->k; | |
72 | const octet *p; | |
73 | unsigned i, j, ii; | |
74 | ||
75 | KSZ_ASSERT(mars, sz); | |
76 | ||
77 | /* --- Copy the key into the temporary buffer --- */ | |
78 | ||
79 | p = buf; | |
80 | for (i = 0; i < sz/4; i++) { | |
81 | t[i] = LOAD32_L(p); | |
82 | p += 4; | |
83 | } | |
84 | t[i++] = sz/4; | |
85 | for (; i < 15; i++) | |
86 | t[i] = 0; | |
87 | ||
88 | /* --- Now spit out the actual key material --- */ | |
89 | ||
90 | for (j = 0; j < 4; j++) { | |
91 | uint32 x; | |
92 | ||
93 | /* --- Do the linear mixing stage --- */ | |
94 | ||
95 | for (i = 0; i < 15; i++) { | |
96 | x = t[(i + 8)%15] ^ t[(i + 13)%15]; | |
97 | t[i] ^= ROL32(x, 3) ^ ((i << 2) | j); | |
98 | } | |
99 | ||
100 | /* --- Now do the Feistel stirring stage --- */ | |
101 | ||
102 | x = t[14]; | |
103 | for (ii = 0; ii < 4; ii++) { | |
104 | for (i = 0; i < 15; i++) { | |
105 | x = t[i] + s[x & 511u]; | |
106 | t[i] = x = ROL32(x, 9); | |
107 | } | |
108 | } | |
109 | ||
110 | /* --- And spit out the key material --- */ | |
111 | ||
112 | for (i = 0; i < 10; i++) | |
113 | *kk++ = t[(4 * i)%15]; | |
114 | } | |
115 | ||
116 | /* --- Finally, fix up the multiplicative entries --- */ | |
117 | ||
118 | for (i = 5; i < 37; i += 2) { | |
119 | uint32 w, m, x; | |
120 | j = k->k[i] & 3u; | |
121 | w = k->k[i] | 3u; | |
122 | ||
123 | /* --- Compute the magic mask value --- */ | |
124 | ||
125 | m = 0; | |
126 | for (ii = 0; ii <= 22; ii++) { | |
127 | x = w >> ii; | |
128 | if ((x & 0x3ff) == 0x3ff || (x & 0x3ff) == 0) | |
129 | m |= 0x3ff << ii; | |
130 | } | |
131 | m &= ~(((w ^ (w << 1)) | (w ^ (w >> 1))) | 0x80000003); | |
132 | ||
133 | /* --- Add in the bias entry to fix up the key --- */ | |
134 | ||
135 | x = ROL32(bb[j], k->k[i - 1]); | |
136 | k->k[i] = w ^ (x & m); | |
137 | } | |
138 | } | |
139 | ||
140 | /* --- @mars_eblk@, @mars_dblk@ --- * | |
141 | * | |
142 | * Arguments: @const mars_ctx *k@ = pointer to key block | |
143 | * @const uint32 s[4]@ = pointer to source block | |
144 | * @uint32 d[4]@ = pointer to destination block | |
145 | * | |
146 | * Returns: --- | |
147 | * | |
148 | * Use: Low-level block encryption and decryption. | |
149 | */ | |
150 | ||
151 | #define KADD(k, a, b, c, d) a += *k++, b += *k++, c += *k++, d += *k++ | |
152 | #define KSUB(k, a, b, c, d) a -= *k++, b -= *k++, c -= *k++, d -= *k++ | |
153 | #define IKADD(k, a, b, c, d) d += *--k, c += *--k, b += *--k, a += *--k | |
154 | #define IKSUB(k, a, b, c, d) d -= *--k, c -= *--k, b -= *--k, a -= *--k | |
155 | ||
156 | #define MIX(a, b, c, d) do { \ | |
45c0fd36 MW |
157 | b ^= s0[(a >> 0) & 0xff]; \ |
158 | b += s1[(a >> 8) & 0xff]; \ | |
3bef8c14 | 159 | c += s0[(a >> 16) & 0xff]; \ |
160 | d ^= s1[(a >> 24) & 0xff]; \ | |
161 | a = ROL32(a, 8); \ | |
162 | } while (0) | |
163 | ||
164 | #define IMIX(a, b, c, d) do { \ | |
165 | a = ROR32(a, 8); \ | |
166 | d ^= s1[(a >> 24) & 0xff]; \ | |
167 | c -= s0[(a >> 16) & 0xff]; \ | |
45c0fd36 MW |
168 | b -= s1[(a >> 8) & 0xff]; \ |
169 | b ^= s0[(a >> 0) & 0xff]; \ | |
3bef8c14 | 170 | } while (0) |
171 | ||
172 | #define E(x, y, z, k, a) do { \ | |
173 | uint32 kx = *k++, ky = *k++; \ | |
174 | y = a + kx; \ | |
175 | a = ROL32(a, 13); z = a * ky; z = ROL32(z, 5); \ | |
176 | x = s[y & 511u] ^ z; y = ROL32(y, z); \ | |
177 | z = ROL32(z, 5); x ^= z; x = ROL32(x, z); \ | |
178 | } while (0) | |
179 | ||
180 | #define IE(x, y, z, k, a) do { \ | |
181 | uint32 ky = *--k, kx = *--k; \ | |
182 | z = a * ky; \ | |
183 | a = ROR32(a, 13); y = a + kx; z = ROL32(z, 5); \ | |
184 | x = s[y & 511u] ^ z; y = ROL32(y, z); \ | |
185 | z = ROL32(z, 5); x ^= z; x = ROL32(x, z); \ | |
186 | } while (0) | |
187 | ||
188 | #define ROUND(k, a, b, c, d) do { \ | |
189 | uint32 x, y, z; \ | |
190 | E(x, y, z, k, a); \ | |
191 | b += x; c += y; d ^= z; \ | |
192 | } while (0) | |
45c0fd36 | 193 | |
3bef8c14 | 194 | #define IROUND(k, a, b, c, d) do { \ |
195 | uint32 x, y, z; \ | |
196 | IE(x, y, z, k, a); \ | |
197 | b -= x; c -= y; d ^= z; \ | |
198 | } while (0) | |
199 | ||
200 | void mars_eblk(const mars_ctx *k, const uint32 *src, uint32 *dst) | |
201 | { | |
202 | uint32 a, b, c, d; | |
203 | const uint32 *kk = k->k; | |
204 | ||
205 | a = src[0], b = src[1], c = src[2], d = src[3]; | |
206 | KADD(kk, a, b, c, d); | |
207 | ||
208 | MIX(a, b, c, d); a += d; MIX(b, c, d, a); b += c; | |
209 | MIX(c, d, a, b); MIX(d, a, b, c); | |
210 | MIX(a, b, c, d); a += d; MIX(b, c, d, a); b += c; | |
211 | MIX(c, d, a, b); MIX(d, a, b, c); | |
212 | ||
213 | ROUND(kk, a, b, c, d); ROUND(kk, b, c, d, a); | |
214 | ROUND(kk, c, d, a, b); ROUND(kk, d, a, b, c); | |
215 | ROUND(kk, a, b, c, d); ROUND(kk, b, c, d, a); | |
216 | ROUND(kk, c, d, a, b); ROUND(kk, d, a, b, c); | |
217 | ||
218 | ROUND(kk, a, d, c, b); ROUND(kk, b, a, d, c); | |
219 | ROUND(kk, c, b, a, d); ROUND(kk, d, c, b, a); | |
220 | ROUND(kk, a, d, c, b); ROUND(kk, b, a, d, c); | |
221 | ROUND(kk, c, b, a, d); ROUND(kk, d, c, b, a); | |
222 | ||
223 | IMIX(a, d, c, b); IMIX(b, a, d, c); | |
224 | c -= b; IMIX(c, b, a, d); d -= a; IMIX(d, c, b, a); | |
225 | IMIX(a, d, c, b); IMIX(b, a, d, c); | |
226 | c -= b; IMIX(c, b, a, d); d -= a; IMIX(d, c, b, a); | |
227 | ||
228 | KSUB(kk, a, b, c, d); | |
229 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; | |
230 | } | |
231 | ||
232 | void mars_dblk(const mars_ctx *k, const uint32 *src, uint32 *dst) | |
233 | { | |
234 | uint32 a, b, c, d; | |
235 | const uint32 *kk = k->k + 40; | |
236 | ||
237 | a = src[0], b = src[1], c = src[2], d = src[3]; | |
238 | IKADD(kk, a, b, c, d); | |
239 | ||
240 | MIX(d, c, b, a); d += a; MIX(c, b, a, d); c += b; | |
241 | MIX(b, a, d, c); MIX(a, d, c, b); | |
242 | MIX(d, c, b, a); d += a; MIX(c, b, a, d); c += b; | |
243 | MIX(b, a, d, c); MIX(a, d, c, b); | |
244 | ||
245 | IROUND(kk, d, c, b, a); IROUND(kk, c, b, a, d); | |
246 | IROUND(kk, b, a, d, c); IROUND(kk, a, d, c, b); | |
247 | IROUND(kk, d, c, b, a); IROUND(kk, c, b, a, d); | |
248 | IROUND(kk, b, a, d, c); IROUND(kk, a, d, c, b); | |
249 | ||
250 | IROUND(kk, d, a, b, c); IROUND(kk, c, d, a, b); | |
251 | IROUND(kk, b, c, d, a); IROUND(kk, a, b, c, d); | |
252 | IROUND(kk, d, a, b, c); IROUND(kk, c, d, a, b); | |
253 | IROUND(kk, b, c, d, a); IROUND(kk, a, b, c, d); | |
254 | ||
255 | IMIX(d, a, b, c); IMIX(c, d, a, b); | |
256 | b -= c; IMIX(b, c, d, a); a -= d; IMIX(a, b, c, d); | |
257 | IMIX(d, a, b, c); IMIX(c, d, a, b); | |
258 | b -= c; IMIX(b, c, d, a); a -= d; IMIX(a, b, c, d); | |
259 | ||
260 | IKSUB(kk, a, b, c, d); | |
261 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; | |
262 | } | |
263 | ||
264 | BLKC_TEST(MARS, mars) | |
265 | ||
266 | /*----- That's all, folks -------------------------------------------------*/ |