3 * $Id: rc2.c,v 1.2 2001/04/29 17:39:52 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 /*----- Revision history --------------------------------------------------*
33 * Revision 1.2 2001/04/29 17:39:52 mdw
34 * Moved big horrible table to a separate header.
36 * Revision 1.1 2000/06/17 11:54:34 mdw
41 /*----- Header files ------------------------------------------------------*/
46 #include <mLib/bits.h>
54 /*----- Global variables --------------------------------------------------*/
56 const octet rc2_keysz
[] = { KSZ_RANGE
, RC2_KEYSZ
, 1, 128, 1 };
58 /*----- Important tables --------------------------------------------------*/
60 static const octet pi
[256] = RC2_PI
;
62 /*----- Main code ---------------------------------------------------------*/
64 /* --- @rc2_braindamage@ --- *
66 * Arguments: @rc2_ctx *k@ = pointer to context to initialize
67 * @const void *buf@ = pointer to key material
68 * @size_t sz@ = size of key material in bytes
69 * @unsigned eb@ = desired effective key size, in bits
73 * Use: Initializes an RC2 expanded key, and braindamages it to the
74 * requested effective key size. This is here for compatibility
75 * reasons. You should be using @rc2_init@ in normal code,
76 * which doesn't actually apply braindamage.
79 void rc2_braindamage(rc2_ctx
*k
, const void *buf
, size_t sz
, unsigned eb
)
89 /* --- Compute the braindamage parameters --- */
92 tm
= 0xff & ((1 << (8 + eb
- 8 * t8
)) - 1);
94 /* --- Copy and expand the initial key --- */
100 for (i
= sz
; i
< sizeof(l
); i
++)
101 l
[i
] = pi
[U8(l
[i
- 1] + l
[i
- sz
])];
103 /* --- Braindamage the key --- */
106 l
[i
] = pi
[l
[i
] & tm
];
109 l
[i
] = pi
[U8(l
[i
+ 1] ^ l
[i
+ t8
])];
112 /* --- Write it to the key block --- */
115 for (i
= 0; i
< sizeof(l
); i
+= 2)
116 *kk
++ = LOAD16_L(l
+ i
);
120 /* --- @rc2_init@ --- *
122 * Arguments: @rc2_ctx *k@ = pointer to context to initialize
123 * @const void *buf@ = pointer to key material
124 * @size_t sz@ = size of key material in bytes
128 * Use: Initializes an RC2 expanded key. The effective key size is
129 * set to be equal to the real key size, in bits.
132 void rc2_init(rc2_ctx
*k
, const void *buf
, size_t sz
)
134 rc2_braindamage(k
, buf
, sz
, sz
* 8);
137 /*----- Encryption and decryption -----------------------------------------*/
139 #define MIX(a, b, c, d, r, kk) do { \
140 a += *kk++ + (d & c) + (~d & b); \
144 #define MASH(a, d, k) do { \
148 #define UNMIX(a, b, c, d, r, kk) do { \
150 a -= *--kk + (d & c) + (~d & b); \
153 #define UNMASH(a, d, k) do { \
157 /* --- @rc2_eblk@, @rc2_dblk@ --- *
159 * Arguments: @const rc2_ctx *k@ = pointer to RC2 context
160 * @const uint32 s[2]@ = pointer to source block
161 * @const uint32 d[2]@ = pointer to destination block
165 * Use: Low-level block encryption and decryption.
168 void rc2_eblk(const rc2_ctx
*k
, const uint32
*s
, uint32
*dst
)
170 uint16 a
= U16(s
[0] >> 0), b
= U16(s
[0] >> 16);
171 uint16 c
= U16(s
[1] >> 0), d
= U16(s
[1] >> 16);
172 const uint16
*kk
= k
->k
;
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
);
196 MIX(a
, b
, c
, d
, 1, kk
); MIX(b
, c
, d
, a
, 2, kk
);
197 MIX(c
, d
, a
, b
, 3, kk
); MIX(d
, a
, b
, c
, 5, kk
);
198 MASH(a
, d
, k
->k
); MASH(b
, a
, k
->k
);
199 MASH(c
, b
, k
->k
); MASH(d
, c
, k
->k
);
200 MIX(a
, b
, c
, d
, 1, kk
); MIX(b
, c
, d
, a
, 2, kk
);
201 MIX(c
, d
, a
, b
, 3, kk
); MIX(d
, a
, b
, c
, 5, kk
);
202 MIX(a
, b
, c
, d
, 1, kk
); MIX(b
, c
, d
, a
, 2, kk
);
203 MIX(c
, d
, a
, b
, 3, kk
); MIX(d
, a
, b
, c
, 5, kk
);
204 MIX(a
, b
, c
, d
, 1, kk
); MIX(b
, c
, d
, a
, 2, kk
);
205 MIX(c
, d
, a
, b
, 3, kk
); MIX(d
, a
, b
, c
, 5, kk
);
206 MIX(a
, b
, c
, d
, 1, kk
); MIX(b
, c
, d
, a
, 2, kk
);
207 MIX(c
, d
, a
, b
, 3, kk
); MIX(d
, a
, b
, c
, 5, kk
);
208 MIX(a
, b
, c
, d
, 1, kk
); MIX(b
, c
, d
, a
, 2, kk
);
209 MIX(c
, d
, a
, b
, 3, kk
); MIX(d
, a
, b
, c
, 5, kk
);
211 dst
[0] = a
| (b
<< 16); dst
[1] = c
| (d
<< 16);
214 void rc2_dblk(const rc2_ctx
*k
, const uint32
*s
, uint32
*dst
)
216 uint16 a
= U16(s
[0] >> 0), b
= U16(s
[0] >> 16);
217 uint16 c
= U16(s
[1] >> 0), d
= U16(s
[1] >> 16);
218 const uint16
*kk
= k
->k
+ 64;
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
);
242 UNMIX(d
, a
, b
, c
, 5, kk
); UNMIX(c
, d
, a
, b
, 3, kk
);
243 UNMIX(b
, c
, d
, a
, 2, kk
); UNMIX(a
, b
, c
, d
, 1, kk
);
244 UNMASH(d
, c
, k
->k
); UNMASH(c
, b
, k
->k
);
245 UNMASH(b
, a
, k
->k
); UNMASH(a
, d
, k
->k
);
246 UNMIX(d
, a
, b
, c
, 5, kk
); UNMIX(c
, d
, a
, b
, 3, kk
);
247 UNMIX(b
, c
, d
, a
, 2, kk
); UNMIX(a
, b
, c
, d
, 1, kk
);
248 UNMIX(d
, a
, b
, c
, 5, kk
); UNMIX(c
, d
, a
, b
, 3, kk
);
249 UNMIX(b
, c
, d
, a
, 2, kk
); UNMIX(a
, b
, c
, d
, 1, kk
);
250 UNMIX(d
, a
, b
, c
, 5, kk
); UNMIX(c
, d
, a
, b
, 3, kk
);
251 UNMIX(b
, c
, d
, a
, 2, kk
); UNMIX(a
, b
, c
, d
, 1, kk
);
252 UNMIX(d
, a
, b
, c
, 5, kk
); UNMIX(c
, d
, a
, b
, 3, kk
);
253 UNMIX(b
, c
, d
, a
, 2, kk
); UNMIX(a
, b
, c
, d
, 1, kk
);
254 UNMIX(d
, a
, b
, c
, 5, kk
); UNMIX(c
, d
, a
, b
, 3, kk
);
255 UNMIX(b
, c
, d
, a
, 2, kk
); UNMIX(a
, b
, c
, d
, 1, kk
);
257 dst
[0] = a
| (b
<< 16); dst
[1] = c
| (d
<< 16);
260 /*----- Custom test rig ---------------------------------------------------*
262 * I need to test the braindamage feature.
267 #include <mLib/quis.h>
268 #include <mLib/testrig.h>
270 static int verify(dstr
*v
)
273 uint32 p
[RC2_BLKSZ
/ 4];
274 uint32 c
[RC2_BLKSZ
/ 4];
275 uint32 d
[RC2_BLKSZ
/ 4];
277 unsigned bd
= *(unsigned *)v
[1].buf
;
280 /* --- Initialize the key buffer --- */
282 dstr_ensure(&b
, RC2_BLKSZ
);
284 rc2_braindamage(&k
, v
[0].buf
, v
[0].len
, bd
);
285 BLKC_LOAD(RC2
, p
, v
[2].buf
);
286 BLKC_LOAD(RC2
, c
, v
[3].buf
);
288 /* --- Test encryption --- */
290 BLKC_MOVE(RC2
, d
, p
);
292 BLKC_STORE(RC2
, b
.buf
, d
);
293 if (memcmp(b
.buf
, v
[3].buf
, RC2_BLKSZ
)) {
295 printf("\nfail encryption:"
297 type_hex
.dump(&v
[0], stdout
);
298 printf("\n\tbraindamage= %u", bd
);
299 printf("\n\tplaintext = "); type_hex
.dump(&v
[2], stdout
);
300 printf("\n\texpected = "); type_hex
.dump(&v
[3], stdout
);
301 printf("\n\tcalculated = "); type_hex
.dump(&b
, stdout
);
305 /* --- Test decryption --- */
307 BLKC_MOVE(RC2
, d
, c
);
309 BLKC_STORE(RC2
, b
.buf
, d
);
310 if (memcmp(b
.buf
, v
[2].buf
, RC2_BLKSZ
)) {
312 printf("\nfail decryption:"
314 type_hex
.dump(&v
[0], stdout
);
315 printf("\n\tbraindamage= %u", bd
);
316 printf("\n\tciphertext = "); type_hex
.dump(&v
[3], stdout
);
317 printf("\n\texpected = "); type_hex
.dump(&v
[2], stdout
);
318 printf("\n\tcalculated = "); type_hex
.dump(&b
, stdout
);
327 static test_chunk defs
[] = {
328 { "rc2", verify
, { &type_hex
, &type_int
, &type_hex
, &type_hex
, 0 } },
332 int main(int argc
, char *argv
[])
334 test_run(argc
, argv
, defs
, SRCDIR
"/tests/rc2");
340 /*----- That's all, folks -------------------------------------------------*/