3 * The MARS block cipher
5 * (c) 2001 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Catacomb.
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.
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.
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,
28 /*----- Header files ------------------------------------------------------*/
33 #include <mLib/bits.h>
40 /*----- Global variables --------------------------------------------------*/
42 const octet mars_keysz[] = { KSZ_RANGE, MARS_KEYSZ, 0, 56, 4 };
44 /*----- Useful tables -----------------------------------------------------*/
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)
51 /*----- Main code ---------------------------------------------------------*/
53 /* --- @mars_init@ --- *
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
61 * Use: Initializes a MARS key buffer. MARS accepts key sizes
62 * between 128 and 448 bits which are a multiple of 32 bits.
65 void mars_init(mars_ctx *k, const void *buf, size_t sz)
74 /* --- Copy the key into the temporary buffer --- */
77 for (i = 0; i < sz/4; i++) {
85 /* --- Now spit out the actual key material --- */
87 for (j = 0; j < 4; j++) {
90 /* --- Do the linear mixing stage --- */
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);
97 /* --- Now do the Feistel stirring stage --- */
100 for (ii = 0; ii < 4; ii++) {
101 for (i = 0; i < 15; i++) {
102 x = t[i] + mars_s[x & 511u];
103 t[i] = x = ROL32(x, 9);
107 /* --- And spit out the key material --- */
109 for (i = 0; i < 10; i++)
110 *kk++ = t[(4 * i)%15];
113 /* --- Finally, fix up the multiplicative entries --- */
115 for (i = 5; i < 37; i += 2) {
120 /* --- Compute the magic mask value --- */
123 for (ii = 0; ii <= 22; ii++) {
125 if ((x & 0x3ff) == 0x3ff || (x & 0x3ff) == 0)
128 m &= ~(((w ^ (w << 1)) | (w ^ (w >> 1))) | 0x80000003);
130 /* --- Add in the bias entry to fix up the key --- */
132 x = ROL32(bb[j], k->k[i - 1]);
133 k->k[i] = w ^ (x & m);
137 /* --- @mars_eblk@, @mars_dblk@ --- *
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
145 * Use: Low-level block encryption and decryption.
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
153 #define MIX(a, b, c, d) do { \
154 b ^= s0[(a >> 0) & 0xff]; \
155 b += s1[(a >> 8) & 0xff]; \
156 c += s0[(a >> 16) & 0xff]; \
157 d ^= s1[(a >> 24) & 0xff]; \
161 #define IMIX(a, b, c, d) do { \
163 d ^= s1[(a >> 24) & 0xff]; \
164 c -= s0[(a >> 16) & 0xff]; \
165 b -= s1[(a >> 8) & 0xff]; \
166 b ^= s0[(a >> 0) & 0xff]; \
169 #define E(x, y, z, k, a) do { \
170 uint32 kx = *k++, ky = *k++; \
172 a = ROL32(a, 13); z = a * ky; z = ROL32(z, 5); \
173 x = mars_s[y & 511u] ^ z; y = ROL32(y, z); \
174 z = ROL32(z, 5); x ^= z; x = ROL32(x, z); \
177 #define IE(x, y, z, k, a) do { \
178 uint32 ky = *--k, kx = *--k; \
180 a = ROR32(a, 13); y = a + kx; z = ROL32(z, 5); \
181 x = mars_s[y & 511u] ^ z; y = ROL32(y, z); \
182 z = ROL32(z, 5); x ^= z; x = ROL32(x, z); \
185 #define ROUND(k, a, b, c, d) do { \
188 b += x; c += y; d ^= z; \
191 #define IROUND(k, a, b, c, d) do { \
194 b -= x; c -= y; d ^= z; \
197 void mars_eblk(const mars_ctx *k, const uint32 *src, uint32 *dst)
200 const uint32 *kk = k->k;
202 a = src[0], b = src[1], c = src[2], d = src[3];
203 KADD(kk, a, b, c, d);
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);
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);
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);
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);
225 KSUB(kk, a, b, c, d);
226 dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
229 void mars_dblk(const mars_ctx *k, const uint32 *src, uint32 *dst)
232 const uint32 *kk = k->k + 40;
234 a = src[0], b = src[1], c = src[2], d = src[3];
235 IKADD(kk, a, b, c, d);
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);
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);
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);
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);
257 IKSUB(kk, a, b, c, d);
258 dst[0] = a; dst[1] = b; dst[2] = c; dst[3] = d;
261 BLKC_TEST(MARS, mars)
263 /*----- That's all, folks -------------------------------------------------*/