3 * $Id: rc2.c,v 1.3 2004/04/08 01:36:15 mdw Exp $
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
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.
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.
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,
30 /*----- Header files ------------------------------------------------------*/
35 #include <mLib/bits.h>
43 /*----- Global variables --------------------------------------------------*/
45 const octet rc2_keysz
[] = { KSZ_RANGE
, RC2_KEYSZ
, 1, 128, 1 };
47 /*----- Important tables --------------------------------------------------*/
49 static const octet pi
[256] = RC2_PI
;
51 /*----- Main code ---------------------------------------------------------*/
53 /* --- @rc2_braindamage@ --- *
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
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.
68 void rc2_braindamage(rc2_ctx
*k
, const void *buf
, size_t sz
, unsigned eb
)
78 /* --- Compute the braindamage parameters --- */
81 tm
= 0xff & ((1 << (8 + eb
- 8 * t8
)) - 1);
83 /* --- Copy and expand the initial key --- */
89 for (i
= sz
; i
< sizeof(l
); i
++)
90 l
[i
] = pi
[U8(l
[i
- 1] + l
[i
- sz
])];
92 /* --- Braindamage the key --- */
98 l
[i
] = pi
[U8(l
[i
+ 1] ^ l
[i
+ t8
])];
101 /* --- Write it to the key block --- */
104 for (i
= 0; i
< sizeof(l
); i
+= 2)
105 *kk
++ = LOAD16_L(l
+ i
);
109 /* --- @rc2_init@ --- *
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
117 * Use: Initializes an RC2 expanded key. The effective key size is
118 * set to be equal to the real key size, in bits.
121 void rc2_init(rc2_ctx
*k
, const void *buf
, size_t sz
)
123 rc2_braindamage(k
, buf
, sz
, sz
* 8);
126 /*----- Encryption and decryption -----------------------------------------*/
128 #define MIX(a, b, c, d, r, kk) do { \
129 a += *kk++ + (d & c) + (~d & b); \
133 #define MASH(a, d, k) do { \
137 #define UNMIX(a, b, c, d, r, kk) do { \
139 a -= *--kk + (d & c) + (~d & b); \
142 #define UNMASH(a, d, k) do { \
146 /* --- @rc2_eblk@, @rc2_dblk@ --- *
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
154 * Use: Low-level block encryption and decryption.
157 void rc2_eblk(const rc2_ctx
*k
, const uint32
*s
, uint32
*dst
)
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
;
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
);
200 dst
[0] = a
| (b
<< 16); dst
[1] = c
| (d
<< 16);
203 void rc2_dblk(const rc2_ctx
*k
, const uint32
*s
, uint32
*dst
)
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;
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
);
246 dst
[0] = a
| (b
<< 16); dst
[1] = c
| (d
<< 16);
249 /*----- Custom test rig ---------------------------------------------------*
251 * I need to test the braindamage feature.
256 #include <mLib/quis.h>
257 #include <mLib/testrig.h>
259 static int verify(dstr
*v
)
262 uint32 p
[RC2_BLKSZ
/ 4];
263 uint32 c
[RC2_BLKSZ
/ 4];
264 uint32 d
[RC2_BLKSZ
/ 4];
266 unsigned bd
= *(unsigned *)v
[1].buf
;
269 /* --- Initialize the key buffer --- */
271 dstr_ensure(&b
, 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
);
277 /* --- Test encryption --- */
279 BLKC_MOVE(RC2
, d
, p
);
281 BLKC_STORE(RC2
, b
.buf
, d
);
282 if (memcmp(b
.buf
, v
[3].buf
, RC2_BLKSZ
)) {
284 printf("\nfail encryption:"
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
);
294 /* --- Test decryption --- */
296 BLKC_MOVE(RC2
, d
, c
);
298 BLKC_STORE(RC2
, b
.buf
, d
);
299 if (memcmp(b
.buf
, v
[2].buf
, RC2_BLKSZ
)) {
301 printf("\nfail decryption:"
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
);
316 static test_chunk defs
[] = {
317 { "rc2", verify
, { &type_hex
, &type_int
, &type_hex
, &type_hex
, 0 } },
321 int main(int argc
, char *argv
[])
323 test_run(argc
, argv
, defs
, SRCDIR
"/tests/rc2");
329 /*----- That's all, folks -------------------------------------------------*/