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tiger-mktab.c: Don't have printf swallow a kludge64 whole.
[u/mdw/catacomb] / rc2.c
1 /* -*-c-*-
2 *
3 * $Id: rc2.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
4 *
5 * The RC2 block cipher
6 *
7 * (c) 2000 Straylight/Edgeware
8 */
9
10 /*----- Licensing notice --------------------------------------------------*
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.
18 *
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.
23 *
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
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 "paranoia.h"
40 #include "rc2.h"
41 #include "rc2-tab.h"
42
43 /*----- Global variables --------------------------------------------------*/
44
45 const octet rc2_keysz[] = { KSZ_RANGE, RC2_KEYSZ, 1, 128, 1 };
46
47 /*----- Important tables --------------------------------------------------*/
48
49 static const octet pi[256] = RC2_PI;
50
51 /*----- Main code ---------------------------------------------------------*/
52
53 /* --- @rc2_braindamage@ --- *
54 *
55 * Arguments: @rc2_ctx *k@ = pointer to context to initialize
56 * @const void *buf@ = pointer to key material
57 * @size_t sz@ = size of key material in bytes
58 * @unsigned eb@ = desired effective key size, in bits
59 *
60 * Returns: ---
61 *
62 * Use: Initializes an RC2 expanded key, and braindamages it to the
63 * requested effective key size. This is here for compatibility
64 * reasons. You should be using @rc2_init@ in normal code,
65 * which doesn't actually apply braindamage.
66 */
67
68 void rc2_braindamage(rc2_ctx *k, const void *buf, size_t sz, unsigned eb)
69 {
70 unsigned t8;
71 uint16 tm;
72 unsigned i;
73 uint16 *kk;
74 octet l[128];
75
76 KSZ_ASSERT(rc2, sz);
77
78 /* --- Compute the braindamage parameters --- */
79
80 t8 = (eb + 7) / 8;
81 tm = 0xff & ((1 << (8 + eb - 8 * t8)) - 1);
82
83 /* --- Copy and expand the initial key --- */
84
85 if (sz > sizeof(l))
86 sz = sizeof(l);
87 memcpy(l, buf, sz);
88
89 for (i = sz; i < sizeof(l); i++)
90 l[i] = pi[U8(l[i - 1] + l[i - sz])];
91
92 /* --- Braindamage the key --- */
93
94 i = sizeof(l) - t8;
95 l[i] = pi[l[i] & tm];
96 while (i) {
97 i--;
98 l[i] = pi[U8(l[i + 1] ^ l[i + t8])];
99 }
100
101 /* --- Write it to the key block --- */
102
103 kk = k->k;
104 for (i = 0; i < sizeof(l); i += 2)
105 *kk++ = LOAD16_L(l + i);
106 BURN(l);
107 }
108
109 /* --- @rc2_init@ --- *
110 *
111 * Arguments: @rc2_ctx *k@ = pointer to context to initialize
112 * @const void *buf@ = pointer to key material
113 * @size_t sz@ = size of key material in bytes
114 *
115 * Returns: ---
116 *
117 * Use: Initializes an RC2 expanded key. The effective key size is
118 * set to be equal to the real key size, in bits.
119 */
120
121 void rc2_init(rc2_ctx *k, const void *buf, size_t sz)
122 {
123 rc2_braindamage(k, buf, sz, sz * 8);
124 }
125
126 /*----- Encryption and decryption -----------------------------------------*/
127
128 #define MIX(a, b, c, d, r, kk) do { \
129 a += *kk++ + (d & c) + (~d & b); \
130 a = ROL16(a, r); \
131 } while (0)
132
133 #define MASH(a, d, k) do { \
134 a += k[d & 63]; \
135 } while (0)
136
137 #define UNMIX(a, b, c, d, r, kk) do { \
138 a = ROR16(a, r); \
139 a -= *--kk + (d & c) + (~d & b); \
140 } while (0)
141
142 #define UNMASH(a, d, k) do { \
143 a -= k[d & 63]; \
144 } while (0)
145
146 /* --- @rc2_eblk@, @rc2_dblk@ --- *
147 *
148 * Arguments: @const rc2_ctx *k@ = pointer to RC2 context
149 * @const uint32 s[2]@ = pointer to source block
150 * @const uint32 d[2]@ = pointer to destination block
151 *
152 * Returns: ---
153 *
154 * Use: Low-level block encryption and decryption.
155 */
156
157 void rc2_eblk(const rc2_ctx *k, const uint32 *s, uint32 *dst)
158 {
159 uint16 a = U16(s[0] >> 0), b = U16(s[0] >> 16);
160 uint16 c = U16(s[1] >> 0), d = U16(s[1] >> 16);
161 const uint16 *kk = k->k;
162
163 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
164 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
165 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
166 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
167 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
168 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
169 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
170 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
171 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
172 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
173 MASH(a, d, k->k); MASH(b, a, k->k);
174 MASH(c, b, k->k); MASH(d, c, k->k);
175 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
176 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
177 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
178 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
179 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
180 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
181 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
182 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
183 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
184 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
185 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
186 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
187 MASH(a, d, k->k); MASH(b, a, k->k);
188 MASH(c, b, k->k); MASH(d, c, k->k);
189 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
190 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
191 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
192 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
193 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
194 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
195 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
196 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
197 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
198 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
199
200 dst[0] = a | (b << 16); dst[1] = c | (d << 16);
201 }
202
203 void rc2_dblk(const rc2_ctx *k, const uint32 *s, uint32 *dst)
204 {
205 uint16 a = U16(s[0] >> 0), b = U16(s[0] >> 16);
206 uint16 c = U16(s[1] >> 0), d = U16(s[1] >> 16);
207 const uint16 *kk = k->k + 64;
208
209 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
210 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
211 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
212 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
213 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
214 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
215 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
216 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
217 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
218 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
219 UNMASH(d, c, k->k); UNMASH(c, b, k->k);
220 UNMASH(b, a, k->k); UNMASH(a, d, k->k);
221 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
222 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
223 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
224 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
225 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
226 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
227 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
228 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
229 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
230 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
231 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
232 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
233 UNMASH(d, c, k->k); UNMASH(c, b, k->k);
234 UNMASH(b, a, k->k); UNMASH(a, d, k->k);
235 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
236 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
237 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
238 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
239 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
240 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
241 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
242 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
243 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
244 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
245
246 dst[0] = a | (b << 16); dst[1] = c | (d << 16);
247 }
248
249 /*----- Custom test rig ---------------------------------------------------*
250 *
251 * I need to test the braindamage feature.
252 */
253
254 #ifdef TEST_RIG
255
256 #include <mLib/quis.h>
257 #include <mLib/testrig.h>
258
259 static int verify(dstr *v)
260 {
261 rc2_ctx k;
262 uint32 p[RC2_BLKSZ / 4];
263 uint32 c[RC2_BLKSZ / 4];
264 uint32 d[RC2_BLKSZ / 4];
265 dstr b = DSTR_INIT;
266 unsigned bd = *(unsigned *)v[1].buf;
267 int ok = 1;
268
269 /* --- Initialize the key buffer --- */
270
271 dstr_ensure(&b, RC2_BLKSZ);
272 b.len = RC2_BLKSZ;
273 rc2_braindamage(&k, v[0].buf, v[0].len, bd);
274 BLKC_LOAD(RC2, p, v[2].buf);
275 BLKC_LOAD(RC2, c, v[3].buf);
276
277 /* --- Test encryption --- */
278
279 BLKC_MOVE(RC2, d, p);
280 rc2_eblk(&k, d, d);
281 BLKC_STORE(RC2, b.buf, d);
282 if (memcmp(b.buf, v[3].buf, RC2_BLKSZ)) {
283 ok = 0;
284 printf("\nfail encryption:"
285 "\n\tkey = ");
286 type_hex.dump(&v[0], stdout);
287 printf("\n\tbraindamage= %u", bd);
288 printf("\n\tplaintext = "); type_hex.dump(&v[2], stdout);
289 printf("\n\texpected = "); type_hex.dump(&v[3], stdout);
290 printf("\n\tcalculated = "); type_hex.dump(&b, stdout);
291 putchar('\n');
292 }
293
294 /* --- Test decryption --- */
295
296 BLKC_MOVE(RC2, d, c);
297 rc2_dblk(&k, d, d);
298 BLKC_STORE(RC2, b.buf, d);
299 if (memcmp(b.buf, v[2].buf, RC2_BLKSZ)) {
300 ok = 0;
301 printf("\nfail decryption:"
302 "\n\tkey = ");
303 type_hex.dump(&v[0], stdout);
304 printf("\n\tbraindamage= %u", bd);
305 printf("\n\tciphertext = "); type_hex.dump(&v[3], stdout);
306 printf("\n\texpected = "); type_hex.dump(&v[2], stdout);
307 printf("\n\tcalculated = "); type_hex.dump(&b, stdout);
308 putchar('\n');
309 }
310
311 /* --- Return --- */
312
313 return (ok);
314 }
315
316 static test_chunk defs[] = {
317 { "rc2", verify, { &type_hex, &type_int, &type_hex, &type_hex, 0 } },
318 { 0, 0, { 0 } }
319 };
320
321 int main(int argc, char *argv[])
322 {
323 test_run(argc, argv, defs, SRCDIR"/tests/rc2");
324 return (0);
325 }
326
327 #endif
328
329 /*----- That's all, folks -------------------------------------------------*/
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)