3a65506d |
1 | /* -*-c-*- |
2 | * |
3 | * $Id: rc2.c,v 1.1 2000/06/17 11:54:34 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 | /*----- Revision history --------------------------------------------------* |
31 | * |
32 | * $Log: rc2.c,v $ |
33 | * Revision 1.1 2000/06/17 11:54:34 mdw |
34 | * New cipher. |
35 | * |
36 | */ |
37 | |
38 | /*----- Header files ------------------------------------------------------*/ |
39 | |
40 | #include <assert.h> |
41 | #include <stdio.h> |
42 | |
43 | #include <mLib/bits.h> |
44 | |
45 | #include "blkc.h" |
46 | #include "gcipher.h" |
47 | #include "paranoia.h" |
48 | #include "rc2.h" |
49 | |
50 | /*----- Global variables --------------------------------------------------*/ |
51 | |
52 | const octet rc2_keysz[] = { KSZ_RANGE, RC2_KEYSZ, 1, 128, 1 }; |
53 | |
54 | /*----- Important tables --------------------------------------------------*/ |
55 | |
56 | static const octet pi[] = { |
57 | 0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, |
58 | 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d, |
59 | 0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e, |
60 | 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2, |
61 | 0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13, |
62 | 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32, |
63 | 0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, |
64 | 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82, |
65 | 0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c, |
66 | 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc, |
67 | 0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, |
68 | 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26, |
69 | 0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57, |
70 | 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03, |
71 | 0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7, |
72 | 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7, |
73 | 0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, |
74 | 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a, |
75 | 0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74, |
76 | 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec, |
77 | 0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, |
78 | 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39, |
79 | 0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a, |
80 | 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31, |
81 | 0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae, |
82 | 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9, |
83 | 0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, |
84 | 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9, |
85 | 0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0, |
86 | 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e, |
87 | 0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, |
88 | 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad |
89 | }; |
90 | |
91 | /*----- Main code ---------------------------------------------------------*/ |
92 | |
93 | /* --- @rc2_braindamage@ --- * |
94 | * |
95 | * Arguments: @rc2_ctx *k@ = pointer to context to initialize |
96 | * @const void *buf@ = pointer to key material |
97 | * @size_t sz@ = size of key material in bytes |
98 | * @unsigned eb@ = desired effective key size, in bits |
99 | * |
100 | * Returns: --- |
101 | * |
102 | * Use: Initializes an RC2 expanded key, and braindamages it to the |
103 | * requested effective key size. This is here for compatibility |
104 | * reasons. You should be using @rc2_init@ in normal code, |
105 | * which doesn't actually apply braindamage. |
106 | */ |
107 | |
108 | void rc2_braindamage(rc2_ctx *k, const void *buf, size_t sz, unsigned eb) |
109 | { |
110 | unsigned t8; |
111 | uint16 tm; |
112 | unsigned i; |
113 | uint16 *kk; |
114 | octet l[128]; |
115 | |
116 | KSZ_ASSERT(rc2, sz); |
117 | |
118 | /* --- Compute the braindamage parameters --- */ |
119 | |
120 | t8 = (eb + 7) / 8; |
121 | tm = 0xff & ((1 << (8 + eb - 8 * t8)) - 1); |
122 | |
123 | /* --- Copy and expand the initial key --- */ |
124 | |
125 | if (sz > sizeof(l)) |
126 | sz = sizeof(l); |
127 | memcpy(l, buf, sz); |
128 | |
129 | for (i = sz; i < sizeof(l); i++) |
130 | l[i] = pi[U8(l[i - 1] + l[i - sz])]; |
131 | |
132 | /* --- Braindamage the key --- */ |
133 | |
134 | i = sizeof(l) - t8; |
135 | l[i] = pi[l[i] & tm]; |
136 | while (i) { |
137 | i--; |
138 | l[i] = pi[U8(l[i + 1] ^ l[i + t8])]; |
139 | } |
140 | |
141 | /* --- Write it to the key block --- */ |
142 | |
143 | kk = k->k; |
144 | for (i = 0; i < sizeof(l); i += 2) |
145 | *kk++ = LOAD16_L(l + i); |
146 | BURN(l); |
147 | } |
148 | |
149 | /* --- @rc2_init@ --- * |
150 | * |
151 | * Arguments: @rc2_ctx *k@ = pointer to context to initialize |
152 | * @const void *buf@ = pointer to key material |
153 | * @size_t sz@ = size of key material in bytes |
154 | * |
155 | * Returns: --- |
156 | * |
157 | * Use: Initializes an RC2 expanded key. The effective key size is |
158 | * set to be equal to the real key size, in bits. |
159 | */ |
160 | |
161 | void rc2_init(rc2_ctx *k, const void *buf, size_t sz) |
162 | { |
163 | rc2_braindamage(k, buf, sz, sz * 8); |
164 | } |
165 | |
166 | /*----- Encryption and decryption -----------------------------------------*/ |
167 | |
168 | #define MIX(a, b, c, d, r, kk) do { \ |
169 | a += *kk++ + (d & c) + (~d & b); \ |
170 | a = ROL16(a, r); \ |
171 | } while (0) |
172 | |
173 | #define MASH(a, d, k) do { \ |
174 | a += k[d & 63]; \ |
175 | } while (0) |
176 | |
177 | #define UNMIX(a, b, c, d, r, kk) do { \ |
178 | a = ROR16(a, r); \ |
179 | a -= *--kk + (d & c) + (~d & b); \ |
180 | } while (0) |
181 | |
182 | #define UNMASH(a, d, k) do { \ |
183 | a -= k[d & 63]; \ |
184 | } while (0) |
185 | |
186 | /* --- @rc2_eblk@, @rc2_dblk@ --- * |
187 | * |
188 | * Arguments: @const rc2_ctx *k@ = pointer to RC2 context |
189 | * @const uint32 s[2]@ = pointer to source block |
190 | * @const uint32 d[2]@ = pointer to destination block |
191 | * |
192 | * Returns: --- |
193 | * |
194 | * Use: Low-level block encryption and decryption. |
195 | */ |
196 | |
197 | void rc2_eblk(const rc2_ctx *k, const uint32 *s, uint32 *dst) |
198 | { |
199 | uint16 a = U16(s[0] >> 0), b = U16(s[0] >> 16); |
200 | uint16 c = U16(s[1] >> 0), d = U16(s[1] >> 16); |
201 | const uint16 *kk = k->k; |
202 | |
203 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
204 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
205 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
206 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
207 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
208 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
209 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
210 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
211 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
212 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
213 | MASH(a, d, k->k); MASH(b, a, k->k); |
214 | MASH(c, b, k->k); MASH(d, c, k->k); |
215 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
216 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
217 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
218 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
219 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
220 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
221 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
222 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
223 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
224 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
225 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
226 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
227 | MASH(a, d, k->k); MASH(b, a, k->k); |
228 | MASH(c, b, k->k); MASH(d, c, k->k); |
229 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
230 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
231 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
232 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
233 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
234 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
235 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
236 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
237 | MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk); |
238 | MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk); |
239 | |
240 | dst[0] = a | (b << 16); dst[1] = c | (d << 16); |
241 | } |
242 | |
243 | void rc2_dblk(const rc2_ctx *k, const uint32 *s, uint32 *dst) |
244 | { |
245 | uint16 a = U16(s[0] >> 0), b = U16(s[0] >> 16); |
246 | uint16 c = U16(s[1] >> 0), d = U16(s[1] >> 16); |
247 | const uint16 *kk = k->k + 64; |
248 | |
249 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
250 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
251 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
252 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
253 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
254 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
255 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
256 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
257 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
258 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
259 | UNMASH(d, c, k->k); UNMASH(c, b, k->k); |
260 | UNMASH(b, a, k->k); UNMASH(a, d, k->k); |
261 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
262 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
263 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
264 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
265 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
266 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
267 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
268 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
269 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
270 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
271 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
272 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
273 | UNMASH(d, c, k->k); UNMASH(c, b, k->k); |
274 | UNMASH(b, a, k->k); UNMASH(a, d, k->k); |
275 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
276 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
277 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
278 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
279 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
280 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
281 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
282 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
283 | UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk); |
284 | UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk); |
285 | |
286 | dst[0] = a | (b << 16); dst[1] = c | (d << 16); |
287 | } |
288 | |
289 | /*----- Custom test rig ---------------------------------------------------* |
290 | * |
291 | * I need to test the braindamage feature. |
292 | */ |
293 | |
294 | #ifdef TEST_RIG |
295 | |
296 | #include <mLib/quis.h> |
297 | #include <mLib/testrig.h> |
298 | |
299 | static int verify(dstr *v) |
300 | { |
301 | rc2_ctx k; |
302 | uint32 p[RC2_BLKSZ / 4]; |
303 | uint32 c[RC2_BLKSZ / 4]; |
304 | uint32 d[RC2_BLKSZ / 4]; |
305 | dstr b = DSTR_INIT; |
306 | unsigned bd = *(unsigned *)v[1].buf; |
307 | int ok = 1; |
308 | |
309 | /* --- Initialize the key buffer --- */ |
310 | |
311 | dstr_ensure(&b, RC2_BLKSZ); |
312 | b.len = RC2_BLKSZ; |
313 | rc2_braindamage(&k, v[0].buf, v[0].len, bd); |
314 | BLKC_LOAD(RC2, p, v[2].buf); |
315 | BLKC_LOAD(RC2, c, v[3].buf); |
316 | |
317 | /* --- Test encryption --- */ |
318 | |
319 | BLKC_MOVE(RC2, d, p); |
320 | rc2_eblk(&k, d, d); |
321 | BLKC_STORE(RC2, b.buf, d); |
322 | if (memcmp(b.buf, v[3].buf, RC2_BLKSZ)) { |
323 | ok = 0; |
324 | printf("\nfail encryption:" |
325 | "\n\tkey = "); |
326 | type_hex.dump(&v[0], stdout); |
327 | printf("\n\tbraindamage= %u", bd); |
328 | printf("\n\tplaintext = "); type_hex.dump(&v[2], stdout); |
329 | printf("\n\texpected = "); type_hex.dump(&v[3], stdout); |
330 | printf("\n\tcalculated = "); type_hex.dump(&b, stdout); |
331 | putchar('\n'); |
332 | } |
333 | |
334 | /* --- Test decryption --- */ |
335 | |
336 | BLKC_MOVE(RC2, d, c); |
337 | rc2_dblk(&k, d, d); |
338 | BLKC_STORE(RC2, b.buf, d); |
339 | if (memcmp(b.buf, v[2].buf, RC2_BLKSZ)) { |
340 | ok = 0; |
341 | printf("\nfail decryption:" |
342 | "\n\tkey = "); |
343 | type_hex.dump(&v[0], stdout); |
344 | printf("\n\tbraindamage= %u", bd); |
345 | printf("\n\tciphertext = "); type_hex.dump(&v[3], stdout); |
346 | printf("\n\texpected = "); type_hex.dump(&v[2], stdout); |
347 | printf("\n\tcalculated = "); type_hex.dump(&b, stdout); |
348 | putchar('\n'); |
349 | } |
350 | |
351 | /* --- Return --- */ |
352 | |
353 | return (ok); |
354 | } |
355 | |
356 | static test_chunk defs[] = { |
357 | { "rc2", verify, { &type_hex, &type_int, &type_hex, &type_hex, 0 } }, |
358 | { 0, 0, { 0 } } |
359 | }; |
360 | |
361 | int main(int argc, char *argv[]) |
362 | { |
363 | test_run(argc, argv, defs, SRCDIR"/tests/rc2"); |
364 | return (0); |
365 | } |
366 | |
367 | #endif |
368 | |
369 | /*----- That's all, folks -------------------------------------------------*/ |