5 * (c) 2000 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 rc2_keysz[] = { KSZ_RANGE, RC2_KEYSZ, 1, 128, 1 };
44 /*----- Important tables --------------------------------------------------*/
46 extern const octet rc2_pi[256];
48 /*----- Main code ---------------------------------------------------------*/
50 /* --- @rc2_braindamage@ --- *
52 * Arguments: @rc2_ctx *k@ = pointer to context to initialize
53 * @const void *buf@ = pointer to key material
54 * @size_t sz@ = size of key material in bytes
55 * @unsigned eb@ = desired effective key size, in bits
59 * Use: Initializes an RC2 expanded key, and braindamages it to the
60 * requested effective key size. This is here for compatibility
61 * reasons. You should be using @rc2_init@ in normal code,
62 * which doesn't actually apply braindamage.
65 void rc2_braindamage(rc2_ctx *k, const void *buf, size_t sz, unsigned eb)
75 /* --- Compute the braindamage parameters --- */
78 tm = 0xff & ((1 << (8 + eb - 8 * t8)) - 1);
80 /* --- Copy and expand the initial key --- */
86 for (i = sz; i < sizeof(l); i++)
87 l[i] = rc2_pi[U8(l[i - 1] + l[i - sz])];
89 /* --- Braindamage the key --- */
92 l[i] = rc2_pi[l[i] & tm];
95 l[i] = rc2_pi[U8(l[i + 1] ^ l[i + t8])];
98 /* --- Write it to the key block --- */
101 for (i = 0; i < sizeof(l); i += 2)
102 *kk++ = LOAD16_L(l + i);
106 /* --- @rc2_init@ --- *
108 * Arguments: @rc2_ctx *k@ = pointer to context to initialize
109 * @const void *buf@ = pointer to key material
110 * @size_t sz@ = size of key material in bytes
114 * Use: Initializes an RC2 expanded key. The effective key size is
115 * set to be equal to the real key size, in bits.
118 void rc2_init(rc2_ctx *k, const void *buf, size_t sz)
120 rc2_braindamage(k, buf, sz, sz * 8);
123 /*----- Encryption and decryption -----------------------------------------*/
125 #define MIX(a, b, c, d, r, kk) do { \
126 a += *kk++ + (d & c) + (~d & b); \
130 #define MASH(a, d, k) do { \
134 #define UNMIX(a, b, c, d, r, kk) do { \
136 a -= *--kk + (d & c) + (~d & b); \
139 #define UNMASH(a, d, k) do { \
143 /* --- @rc2_eblk@, @rc2_dblk@ --- *
145 * Arguments: @const rc2_ctx *k@ = pointer to RC2 context
146 * @const uint32 s[2]@ = pointer to source block
147 * @const uint32 d[2]@ = pointer to destination block
151 * Use: Low-level block encryption and decryption.
154 void rc2_eblk(const rc2_ctx *k, const uint32 *s, uint32 *dst)
156 uint16 a = U16(s[0] >> 0), b = U16(s[0] >> 16);
157 uint16 c = U16(s[1] >> 0), d = U16(s[1] >> 16);
158 const uint16 *kk = k->k;
160 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
161 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
162 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
163 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
164 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
165 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
166 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
167 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
168 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
169 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
170 MASH(a, d, k->k); MASH(b, a, k->k);
171 MASH(c, b, k->k); MASH(d, c, k->k);
172 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
173 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
174 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
175 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
176 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
177 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
178 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
179 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
180 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
181 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
182 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
183 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
184 MASH(a, d, k->k); MASH(b, a, k->k);
185 MASH(c, b, k->k); MASH(d, c, k->k);
186 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
187 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
188 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
189 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
190 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
191 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
192 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
193 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
194 MIX(a, b, c, d, 1, kk); MIX(b, c, d, a, 2, kk);
195 MIX(c, d, a, b, 3, kk); MIX(d, a, b, c, 5, kk);
197 dst[0] = a | (b << 16); dst[1] = c | (d << 16);
200 void rc2_dblk(const rc2_ctx *k, const uint32 *s, uint32 *dst)
202 uint16 a = U16(s[0] >> 0), b = U16(s[0] >> 16);
203 uint16 c = U16(s[1] >> 0), d = U16(s[1] >> 16);
204 const uint16 *kk = k->k + 64;
206 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
207 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
208 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
209 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
210 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
211 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
212 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
213 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
214 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
215 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
216 UNMASH(d, c, k->k); UNMASH(c, b, k->k);
217 UNMASH(b, a, k->k); UNMASH(a, d, k->k);
218 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
219 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
220 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
221 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
222 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
223 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
224 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
225 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
226 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
227 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
228 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
229 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
230 UNMASH(d, c, k->k); UNMASH(c, b, k->k);
231 UNMASH(b, a, k->k); UNMASH(a, d, k->k);
232 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
233 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
234 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
235 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
236 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
237 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
238 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
239 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
240 UNMIX(d, a, b, c, 5, kk); UNMIX(c, d, a, b, 3, kk);
241 UNMIX(b, c, d, a, 2, kk); UNMIX(a, b, c, d, 1, kk);
243 dst[0] = a | (b << 16); dst[1] = c | (d << 16);
246 /*----- Custom test rig ---------------------------------------------------*
248 * I need to test the braindamage feature.
253 #include <mLib/quis.h>
254 #include <mLib/testrig.h>
256 static int verify(dstr *v)
259 uint32 p[RC2_BLKSZ / 4];
260 uint32 c[RC2_BLKSZ / 4];
261 uint32 d[RC2_BLKSZ / 4];
263 unsigned bd = *(unsigned *)v[1].buf;
266 /* --- Initialize the key buffer --- */
268 dstr_ensure(&b, RC2_BLKSZ);
270 rc2_braindamage(&k, v[0].buf, v[0].len, bd);
271 BLKC_LOAD(RC2, p, v[2].buf);
272 BLKC_LOAD(RC2, c, v[3].buf);
274 /* --- Test encryption --- */
276 BLKC_MOVE(RC2, d, p);
278 BLKC_STORE(RC2, b.buf, d);
279 if (memcmp(b.buf, v[3].buf, RC2_BLKSZ)) {
281 printf("\nfail encryption:"
283 type_hex.dump(&v[0], stdout);
284 printf("\n\tbraindamage= %u", bd);
285 printf("\n\tplaintext = "); type_hex.dump(&v[2], stdout);
286 printf("\n\texpected = "); type_hex.dump(&v[3], stdout);
287 printf("\n\tcalculated = "); type_hex.dump(&b, stdout);
291 /* --- Test decryption --- */
293 BLKC_MOVE(RC2, d, c);
295 BLKC_STORE(RC2, b.buf, d);
296 if (memcmp(b.buf, v[2].buf, RC2_BLKSZ)) {
298 printf("\nfail decryption:"
300 type_hex.dump(&v[0], stdout);
301 printf("\n\tbraindamage= %u", bd);
302 printf("\n\tciphertext = "); type_hex.dump(&v[3], stdout);
303 printf("\n\texpected = "); type_hex.dump(&v[2], stdout);
304 printf("\n\tcalculated = "); type_hex.dump(&b, stdout);
313 static test_chunk defs[] = {
314 { "rc2", verify, { &type_hex, &type_int, &type_hex, &type_hex, 0 } },
318 int main(int argc, char *argv[])
320 test_run(argc, argv, defs, SRCDIR"/t/rc2");
326 /*----- That's all, folks -------------------------------------------------*/