Commit | Line | Data |
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3bef8c14 | 1 | /* -*-c-*- |
3bef8c14 | 2 | * |
3 | * The MARS block cipher | |
4 | * | |
5 | * (c) 2001 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
3bef8c14 | 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 | * |
3bef8c14 | 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 | * |
3bef8c14 | 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 | ||
3bef8c14 | 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 "mars.h" | |
3bef8c14 | 38 | #include "paranoia.h" |
39 | ||
40 | /*----- Global variables --------------------------------------------------*/ | |
41 | ||
42 | const octet mars_keysz[] = { KSZ_RANGE, MARS_KEYSZ, 0, 56, 4 }; | |
43 | ||
44 | /*----- Useful tables -----------------------------------------------------*/ | |
45 | ||
e5b61a8d MW |
46 | extern const uint32 mars_s[512]; |
47 | #define s0 (mars_s + 0) | |
48 | #define s1 (mars_s + 256) | |
49 | #define bb (mars_s + 265) | |
3bef8c14 | 50 | |
51 | /*----- Main code ---------------------------------------------------------*/ | |
52 | ||
53 | /* --- @mars_init@ --- * | |
54 | * | |
55 | * Arguments: @mars_ctx *k@ = pointer to key block to fill in | |
56 | * @const void *buf@ = pointer to buffer of key material | |
57 | * @size_t sz@ = size of key material | |
58 | * | |
59 | * Returns: --- | |
60 | * | |
61 | * Use: Initializes a MARS key buffer. MARS accepts key sizes | |
62 | * between 128 and 448 bits which are a multiple of 32 bits. | |
63 | */ | |
64 | ||
65 | void mars_init(mars_ctx *k, const void *buf, size_t sz) | |
66 | { | |
67 | uint32 t[15]; | |
68 | uint32 *kk = k->k; | |
69 | const octet *p; | |
70 | unsigned i, j, ii; | |
71 | ||
72 | KSZ_ASSERT(mars, sz); | |
73 | ||
74 | /* --- Copy the key into the temporary buffer --- */ | |
75 | ||
76 | p = buf; | |
77 | for (i = 0; i < sz/4; i++) { | |
78 | t[i] = LOAD32_L(p); | |
79 | p += 4; | |
80 | } | |
81 | t[i++] = sz/4; | |
82 | for (; i < 15; i++) | |
83 | t[i] = 0; | |
84 | ||
85 | /* --- Now spit out the actual key material --- */ | |
86 | ||
87 | for (j = 0; j < 4; j++) { | |
88 | uint32 x; | |
89 | ||
90 | /* --- Do the linear mixing stage --- */ | |
91 | ||
92 | for (i = 0; i < 15; i++) { | |
93 | x = t[(i + 8)%15] ^ t[(i + 13)%15]; | |
94 | t[i] ^= ROL32(x, 3) ^ ((i << 2) | j); | |
95 | } | |
96 | ||
97 | /* --- Now do the Feistel stirring stage --- */ | |
98 | ||
99 | x = t[14]; | |
100 | for (ii = 0; ii < 4; ii++) { | |
101 | for (i = 0; i < 15; i++) { | |
e5b61a8d | 102 | x = t[i] + mars_s[x & 511u]; |
3bef8c14 | 103 | t[i] = x = ROL32(x, 9); |
104 | } | |
105 | } | |
106 | ||
107 | /* --- And spit out the key material --- */ | |
108 | ||
109 | for (i = 0; i < 10; i++) | |
110 | *kk++ = t[(4 * i)%15]; | |
111 | } | |
112 | ||
113 | /* --- Finally, fix up the multiplicative entries --- */ | |
114 | ||
115 | for (i = 5; i < 37; i += 2) { | |
116 | uint32 w, m, x; | |
117 | j = k->k[i] & 3u; | |
118 | w = k->k[i] | 3u; | |
119 | ||
120 | /* --- Compute the magic mask value --- */ | |
121 | ||
122 | m = 0; | |
123 | for (ii = 0; ii <= 22; ii++) { | |
124 | x = w >> ii; | |
125 | if ((x & 0x3ff) == 0x3ff || (x & 0x3ff) == 0) | |
126 | m |= 0x3ff << ii; | |
127 | } | |
128 | m &= ~(((w ^ (w << 1)) | (w ^ (w >> 1))) | 0x80000003); | |
129 | ||
130 | /* --- Add in the bias entry to fix up the key --- */ | |
131 | ||
132 | x = ROL32(bb[j], k->k[i - 1]); | |
133 | k->k[i] = w ^ (x & m); | |
134 | } | |
135 | } | |
136 | ||
137 | /* --- @mars_eblk@, @mars_dblk@ --- * | |
138 | * | |
139 | * Arguments: @const mars_ctx *k@ = pointer to key block | |
140 | * @const uint32 s[4]@ = pointer to source block | |
141 | * @uint32 d[4]@ = pointer to destination block | |
142 | * | |
143 | * Returns: --- | |
144 | * | |
145 | * Use: Low-level block encryption and decryption. | |
146 | */ | |
147 | ||
148 | #define KADD(k, a, b, c, d) a += *k++, b += *k++, c += *k++, d += *k++ | |
149 | #define KSUB(k, a, b, c, d) a -= *k++, b -= *k++, c -= *k++, d -= *k++ | |
150 | #define IKADD(k, a, b, c, d) d += *--k, c += *--k, b += *--k, a += *--k | |
151 | #define IKSUB(k, a, b, c, d) d -= *--k, c -= *--k, b -= *--k, a -= *--k | |
152 | ||
153 | #define MIX(a, b, c, d) do { \ | |
45c0fd36 MW |
154 | b ^= s0[(a >> 0) & 0xff]; \ |
155 | b += s1[(a >> 8) & 0xff]; \ | |
3bef8c14 | 156 | c += s0[(a >> 16) & 0xff]; \ |
157 | d ^= s1[(a >> 24) & 0xff]; \ | |
158 | a = ROL32(a, 8); \ | |
159 | } while (0) | |
160 | ||
161 | #define IMIX(a, b, c, d) do { \ | |
162 | a = ROR32(a, 8); \ | |
163 | d ^= s1[(a >> 24) & 0xff]; \ | |
164 | c -= s0[(a >> 16) & 0xff]; \ | |
45c0fd36 MW |
165 | b -= s1[(a >> 8) & 0xff]; \ |
166 | b ^= s0[(a >> 0) & 0xff]; \ | |
3bef8c14 | 167 | } while (0) |
168 | ||
169 | #define E(x, y, z, k, a) do { \ | |
170 | uint32 kx = *k++, ky = *k++; \ | |
171 | y = a + kx; \ | |
172 | a = ROL32(a, 13); z = a * ky; z = ROL32(z, 5); \ | |
e5b61a8d | 173 | x = mars_s[y & 511u] ^ z; y = ROL32(y, z); \ |
3bef8c14 | 174 | z = ROL32(z, 5); x ^= z; x = ROL32(x, z); \ |
175 | } while (0) | |
176 | ||
177 | #define IE(x, y, z, k, a) do { \ | |
178 | uint32 ky = *--k, kx = *--k; \ | |
179 | z = a * ky; \ | |
180 | a = ROR32(a, 13); y = a + kx; z = ROL32(z, 5); \ | |
e5b61a8d | 181 | x = mars_s[y & 511u] ^ z; y = ROL32(y, z); \ |
3bef8c14 | 182 | z = ROL32(z, 5); x ^= z; x = ROL32(x, z); \ |
183 | } while (0) | |
184 | ||
185 | #define ROUND(k, a, b, c, d) do { \ | |
186 | uint32 x, y, z; \ | |
187 | E(x, y, z, k, a); \ | |
188 | b += x; c += y; d ^= z; \ | |
189 | } while (0) | |
45c0fd36 | 190 | |
3bef8c14 | 191 | #define IROUND(k, a, b, c, d) do { \ |
192 | uint32 x, y, z; \ | |
193 | IE(x, y, z, k, a); \ | |
194 | b -= x; c -= y; d ^= z; \ | |
195 | } while (0) | |
196 | ||
197 | void mars_eblk(const mars_ctx *k, const uint32 *src, uint32 *dst) | |
198 | { | |
199 | uint32 a, b, c, d; | |
200 | const uint32 *kk = k->k; | |
201 | ||
202 | a = src[0], b = src[1], c = src[2], d = src[3]; | |
203 | KADD(kk, a, b, c, d); | |
204 | ||
205 | MIX(a, b, c, d); a += d; MIX(b, c, d, a); b += c; | |
206 | MIX(c, d, a, b); MIX(d, a, b, c); | |
207 | MIX(a, b, c, d); a += d; MIX(b, c, d, a); b += c; | |
208 | MIX(c, d, a, b); MIX(d, a, b, c); | |
209 | ||
210 | ROUND(kk, a, b, c, d); ROUND(kk, b, c, d, a); | |
211 | ROUND(kk, c, d, a, b); ROUND(kk, d, a, b, c); | |
212 | ROUND(kk, a, b, c, d); ROUND(kk, b, c, d, a); | |
213 | ROUND(kk, c, d, a, b); ROUND(kk, d, a, b, c); | |
214 | ||
215 | ROUND(kk, a, d, c, b); ROUND(kk, b, a, d, c); | |
216 | ROUND(kk, c, b, a, d); ROUND(kk, d, c, b, a); | |
217 | ROUND(kk, a, d, c, b); ROUND(kk, b, a, d, c); | |
218 | ROUND(kk, c, b, a, d); ROUND(kk, d, c, b, a); | |
219 | ||
220 | IMIX(a, d, c, b); IMIX(b, a, d, c); | |
221 | c -= b; IMIX(c, b, a, d); d -= a; IMIX(d, c, b, a); | |
222 | IMIX(a, d, c, b); IMIX(b, a, d, c); | |
223 | c -= b; IMIX(c, b, a, d); d -= a; IMIX(d, c, b, a); | |
224 | ||
225 | KSUB(kk, a, b, c, d); | |
226 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; | |
227 | } | |
228 | ||
229 | void mars_dblk(const mars_ctx *k, const uint32 *src, uint32 *dst) | |
230 | { | |
231 | uint32 a, b, c, d; | |
232 | const uint32 *kk = k->k + 40; | |
233 | ||
234 | a = src[0], b = src[1], c = src[2], d = src[3]; | |
235 | IKADD(kk, a, b, c, d); | |
236 | ||
237 | MIX(d, c, b, a); d += a; MIX(c, b, a, d); c += b; | |
238 | MIX(b, a, d, c); MIX(a, d, c, b); | |
239 | MIX(d, c, b, a); d += a; MIX(c, b, a, d); c += b; | |
240 | MIX(b, a, d, c); MIX(a, d, c, b); | |
241 | ||
242 | IROUND(kk, d, c, b, a); IROUND(kk, c, b, a, d); | |
243 | IROUND(kk, b, a, d, c); IROUND(kk, a, d, c, b); | |
244 | IROUND(kk, d, c, b, a); IROUND(kk, c, b, a, d); | |
245 | IROUND(kk, b, a, d, c); IROUND(kk, a, d, c, b); | |
246 | ||
247 | IROUND(kk, d, a, b, c); IROUND(kk, c, d, a, b); | |
248 | IROUND(kk, b, c, d, a); IROUND(kk, a, b, c, d); | |
249 | IROUND(kk, d, a, b, c); IROUND(kk, c, d, a, b); | |
250 | IROUND(kk, b, c, d, a); IROUND(kk, a, b, c, d); | |
251 | ||
252 | IMIX(d, a, b, c); IMIX(c, d, a, b); | |
253 | b -= c; IMIX(b, c, d, a); a -= d; IMIX(a, b, c, d); | |
254 | IMIX(d, a, b, c); IMIX(c, d, a, b); | |
255 | b -= c; IMIX(b, c, d, a); a -= d; IMIX(a, b, c, d); | |
256 | ||
257 | IKSUB(kk, a, b, c, d); | |
258 | dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d; | |
259 | } | |
260 | ||
261 | BLKC_TEST(MARS, mars) | |
262 | ||
263 | /*----- That's all, folks -------------------------------------------------*/ |