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[u/mdw/catacomb] / ecb-def.h
1 /* -*-c-*-
2 *
3 * $Id: ecb-def.h,v 1.4 2004/04/17 09:58:37 mdw Exp $
4 *
5 * Definitions electronic code book mode
6 *
7 * (c) 1999 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 #ifndef CATACOMB_ECB_DEF_H
31 #define CATACOMB_ECB_DEF_H
32
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36
37 /*----- Header files ------------------------------------------------------*/
38
39 #include <assert.h>
40 #include <string.h>
41
42 #include <mLib/bits.h>
43 #include <mLib/sub.h>
44
45 #ifndef CATACOMB_ARENA_H
46 # include "arena.h"
47 #endif
48
49 #ifndef CATACOMB_BLKC_H
50 # include "blkc.h"
51 #endif
52
53 #ifndef CATACOMB_GCIPHER_H
54 # include "gcipher.h"
55 #endif
56
57 #ifndef CATACOMB_PARANOIA_H
58 # include "paranoia.h"
59 #endif
60
61 /*----- Macros ------------------------------------------------------------*/
62
63 /* --- @ECB_DEF@ --- *
64 *
65 * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
66 *
67 * Use: Creates an implementation for ECB stealing mode.
68 */
69
70 #define ECB_DEF(PRE, pre) \
71 \
72 /* --- @pre_ecbsetkey@ --- * \
73 * \
74 * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \
75 * @const pre_ctx *k@ = pointer to cipher context \
76 * \
77 * Returns: --- \
78 * \
79 * Use: Sets the ECB context to use a different cipher key. \
80 */ \
81 \
82 void pre##_ecbsetkey(pre##_ecbctx *ctx, const pre##_ctx *k) \
83 { \
84 ctx->ctx = *k; \
85 } \
86 \
87 /* --- @pre_ecbinit@ --- * \
88 * \
89 * Arguments: @pre_ecbctx *ctx@ = pointer to cipher context \
90 * @const void *key@ = pointer to the key buffer \
91 * @size_t sz@ = size of the key \
92 * @const void *iv@ = pointer to initialization vector \
93 * \
94 * Returns: --- \
95 * \
96 * Use: Initializes an ECB context ready for use. This is \
97 * equivalent to calls to @pre_init@ and @pre_setkey@. \
98 */ \
99 \
100 void pre##_ecbinit(pre##_ecbctx *ctx, \
101 const void *key, size_t sz, \
102 const void *iv) \
103 { \
104 pre##_init(&ctx->ctx, key, sz); \
105 } \
106 \
107 /* --- @pre_ecbencrypt@ --- * \
108 * \
109 * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \
110 * @const void *src@ = pointer to source data \
111 * @void *dest@ = pointer to destination data \
112 * @size_t sz@ = size of block to be encrypted \
113 * \
114 * Returns: --- \
115 * \
116 * Use: Encrypts a block with a block cipher in ECB mode, with \
117 * ciphertext stealing and other clever tricks. \
118 * Essentially, data can be encrypted in arbitrary sized \
119 * chunks, although decryption must use the same chunks. \
120 */ \
121 \
122 void pre##_ecbencrypt(pre##_ecbctx *ctx, \
123 const void *src, void *dest, \
124 size_t sz) \
125 { \
126 const octet *s = src; \
127 octet *d = dest; \
128 \
129 /* --- Empty blocks are trivial --- */ \
130 \
131 if (!sz) \
132 return; \
133 \
134 /* --- Short blocks aren't allowed in ECB --- * \
135 * \
136 * There's absolutely nothing secure I can do with them. \
137 */ \
138 \
139 assert(((void)"ECB must have at least one whole block to work with", \
140 sz >= PRE##_BLKSZ)); \
141 \
142 /* --- Do the main chunk of encryption --- * \
143 * \
144 * This will do the whole lot if it's a whole number of blocks. Just \
145 * give each block to the cipher in turn. This is trivial. \
146 * Hopefully... \
147 */ \
148 \
149 while (sz >= 2 * PRE##_BLKSZ || sz == PRE##_BLKSZ) { \
150 uint32 x[PRE##_BLKSZ / 4]; \
151 if (!s) \
152 BLKC_ZERO(PRE, x); \
153 else { \
154 BLKC_LOAD(PRE, x, s); \
155 s += PRE##_BLKSZ; \
156 } \
157 pre##_eblk(&ctx->ctx, x, x); \
158 if (d) { \
159 BLKC_STORE(PRE, d, x); \
160 d += PRE##_BLKSZ; \
161 } \
162 sz -= PRE##_BLKSZ; \
163 } \
164 \
165 /* --- Do the tail-end block and bit-left-over --- * \
166 * \
167 * This isn't very efficient. That shouldn't matter much. \
168 */ \
169 \
170 if (sz) { \
171 uint32 x[PRE##_BLKSZ / 4]; \
172 octet b[PRE##_BLKSZ]; \
173 unsigned i; \
174 \
175 /* --- Let @sz@ be the size of the partial block --- */ \
176 \
177 sz -= PRE##_BLKSZ; \
178 \
179 /* --- First stage --- * \
180 * \
181 * Read in the current block, and encrypt it. The first part of \
182 * the result is the partial ciphertext block. Don't write that \
183 * out yet, because I've not read the partial plaintext block. \
184 */ \
185 \
186 if (!s) \
187 BLKC_ZERO(PRE, x); \
188 else { \
189 BLKC_LOAD(PRE, x, s); \
190 s += PRE##_BLKSZ; \
191 } \
192 pre##_eblk(&ctx->ctx, x, x); \
193 BLKC_STORE(PRE, b, x); \
194 \
195 /* --- Second stage --- * \
196 * \
197 * Now move in the partial plaintext block, writing out the \
198 * ciphertext as I go. Then encrypt, and write the complete \
199 * ciphertext block. \
200 */ \
201 \
202 if (d) d += PRE##_BLKSZ; \
203 for (i = 0; i < sz; i++) { \
204 register octet y = b[i]; \
205 b[i] = s[i]; \
206 if (d) d[i] = y; \
207 } \
208 BLKC_LOAD(PRE, x, b); \
209 pre##_eblk(&ctx->ctx, x, x); \
210 if (d) BLKC_STORE(PRE, d - PRE##_BLKSZ, x); \
211 } \
212 \
213 /* --- Done --- */ \
214 \
215 return; \
216 } \
217 \
218 /* --- @pre_ecbdecrypt@ --- * \
219 * \
220 * Arguments: @pre_ecbctx *ctx@ = pointer to ECB context block \
221 * @const void *src@ = pointer to source data \
222 * @void *dest@ = pointer to destination data \
223 * @size_t sz@ = size of block to be encrypted \
224 * \
225 * Returns: --- \
226 * \
227 * Use: Decrypts a block with a block cipher in ECB mode, with \
228 * ciphertext stealing and other clever tricks. \
229 * Essentially, data can be encrypted in arbitrary sized \
230 * chunks, although decryption must use the same chunks. \
231 */ \
232 \
233 void pre##_ecbdecrypt(pre##_ecbctx *ctx, \
234 const void *src, void *dest, \
235 size_t sz) \
236 { \
237 const octet *s = src; \
238 octet *d = dest; \
239 \
240 /* --- Empty blocks are trivial --- */ \
241 \
242 if (!sz) \
243 return; \
244 \
245 /* --- Short blocks aren't allowed in ECB --- * \
246 * \
247 * There's absolutely nothing secure I can do with them. \
248 */ \
249 \
250 assert(((void)"ECB must have at least one whole block to work with", \
251 sz >= PRE##_BLKSZ)); \
252 \
253 /* --- Do the main chunk of decryption --- * \
254 * \
255 * This will do the whole lot if it's a whole number of blocks. \
256 * Each block is just handed to the block cipher in turn. \
257 */ \
258 \
259 while (sz >= 2 * PRE##_BLKSZ || sz == PRE##_BLKSZ) { \
260 uint32 x[PRE##_BLKSZ / 4]; \
261 BLKC_LOAD(PRE, x, s); \
262 pre##_dblk(&ctx->ctx, x, x); \
263 BLKC_STORE(PRE, d, x); \
264 s += PRE##_BLKSZ; \
265 d += PRE##_BLKSZ; \
266 sz -= PRE##_BLKSZ; \
267 } \
268 \
269 /* --- Do the tail-end block and bit-left-over --- * \
270 * \
271 * This isn't very efficient. That shouldn't matter much. \
272 */ \
273 \
274 if (sz) { \
275 uint32 x[PRE##_BLKSZ / 4]; \
276 octet b[PRE##_BLKSZ]; \
277 unsigned i; \
278 \
279 /* --- Let @sz@ be the size of the partial block --- */ \
280 \
281 sz -= PRE##_BLKSZ; \
282 \
283 /* --- First stage --- * \
284 * \
285 * Take the complete ciphertext block, and decrypt it. This block \
286 * is carried over for the next encryption operation. \
287 */ \
288 \
289 BLKC_LOAD(PRE, x, s); \
290 pre##_dblk(&ctx->ctx, x, x); \
291 BLKC_STORE(PRE, b, x); \
292 \
293 /* --- Second stage --- * \
294 * \
295 * The first few bytes are the partial plaintext block. Write that \
296 * and replace with the partial ciphertext block. Then decrypt \
297 * what's left as the complete plaintext. \
298 */ \
299 \
300 s += PRE##_BLKSZ; \
301 d += PRE##_BLKSZ; \
302 for (i = 0; i < sz; i++) { \
303 register octet y = s[i]; \
304 d[i] = b[i]; \
305 b[i] = y; \
306 } \
307 BLKC_LOAD(PRE, x, b); \
308 pre##_dblk(&ctx->ctx, x, x); \
309 BLKC_STORE(PRE, d - PRE##_BLKSZ, x); \
310 } \
311 \
312 /* --- Done --- */ \
313 \
314 return; \
315 } \
316 \
317 /* --- Generic cipher interface --- */ \
318 \
319 static const gcipher_ops gops; \
320 \
321 typedef struct gctx { \
322 gcipher c; \
323 pre##_ecbctx k; \
324 } gctx; \
325 \
326 static gcipher *ginit(const void *k, size_t sz) \
327 { \
328 gctx *g = S_CREATE(gctx); \
329 g->c.ops = &gops; \
330 pre##_ecbinit(&g->k, k, sz, 0); \
331 return (&g->c); \
332 } \
333 \
334 static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \
335 { \
336 gctx *g = (gctx *)c; \
337 pre##_ecbencrypt(&g->k, s, t, sz); \
338 } \
339 \
340 static void gdecrypt(gcipher *c, const void *s, void *t, size_t sz) \
341 { \
342 gctx *g = (gctx *)c; \
343 pre##_ecbdecrypt(&g->k, s, t, sz); \
344 } \
345 \
346 static void gdestroy(gcipher *c) \
347 { \
348 gctx *g = (gctx *)c; \
349 BURN(*g); \
350 S_DESTROY(g); \
351 } \
352 \
353 static const gcipher_ops gops = { \
354 &pre##_ecb, \
355 gencrypt, gdecrypt, gdestroy, 0, 0 \
356 }; \
357 \
358 const gccipher pre##_ecb = { \
359 #pre "-ecb", pre##_keysz, PRE##_BLKSZ, \
360 ginit \
361 }; \
362 \
363 ECB_TEST(PRE, pre)
364
365 /*----- Test rig ----------------------------------------------------------*/
366
367 #ifdef TEST_RIG
368
369 #include <stdio.h>
370
371 #include "daftstory.h"
372
373 /* --- @ECB_TEST@ --- *
374 *
375 * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
376 *
377 * Use: Standard test rig for ECB functions.
378 */
379
380 #define ECB_TEST(PRE, pre) \
381 \
382 /* --- Initial plaintext for the test --- */ \
383 \
384 static const octet text[] = TEXT; \
385 \
386 /* --- Key and IV to use --- */ \
387 \
388 static const octet key[] = KEY; \
389 static const octet iv[] = IV; \
390 \
391 /* --- Buffers for encryption and decryption output --- */ \
392 \
393 static octet ct[sizeof(text)]; \
394 static octet pt[sizeof(text)]; \
395 \
396 static void hexdump(const octet *p, size_t sz) \
397 { \
398 const octet *q = p + sz; \
399 for (sz = 0; p < q; p++, sz++) { \
400 printf("%02x", *p); \
401 if ((sz + 1) % PRE##_BLKSZ == 0) \
402 putchar(':'); \
403 } \
404 } \
405 \
406 int main(void) \
407 { \
408 size_t sz = 0, rest; \
409 pre##_ecbctx ctx; \
410 int status = 0; \
411 int done = 0; \
412 \
413 size_t keysz = PRE##_KEYSZ ? \
414 PRE##_KEYSZ : strlen((const char *)key); \
415 \
416 fputs(#pre "-ecb: ", stdout); \
417 \
418 pre##_ecbinit(&ctx, key, keysz, iv); \
419 \
420 while (sz <= sizeof(text)) { \
421 rest = sizeof(text) - sz; \
422 if ((sz != 0 && sz < PRE##_BLKSZ) || \
423 (rest != 0 && rest < PRE##_BLKSZ)) \
424 goto next; \
425 memcpy(ct, text, sizeof(text)); \
426 pre##_ecbencrypt(&ctx, ct, ct, sz); \
427 pre##_ecbencrypt(&ctx, ct + sz, ct + sz, rest); \
428 memcpy(pt, ct, sizeof(text)); \
429 pre##_ecbdecrypt(&ctx, pt, pt, sz); \
430 pre##_ecbdecrypt(&ctx, pt + sz, pt + sz, rest); \
431 if (memcmp(pt, text, sizeof(text)) == 0) { \
432 done++; \
433 if (sizeof(text) < 40 || done % 8 == 0) \
434 fputc('.', stdout); \
435 if (done % 480 == 0) \
436 fputs("\n\t", stdout); \
437 fflush(stdout); \
438 } else { \
439 printf("\nError (sz = %lu)\n", (unsigned long)sz); \
440 status = 1; \
441 printf("\tplaintext = "); hexdump(text, sz); \
442 printf(", "); hexdump(text + sz, rest); \
443 fputc('\n', stdout); \
444 printf("\tciphertext = "); hexdump(ct, sz); \
445 printf(", "); hexdump(ct + sz, rest); \
446 fputc('\n', stdout); \
447 printf("\trecovered text = "); hexdump(pt, sz); \
448 printf(", "); hexdump(pt + sz, rest); \
449 fputc('\n', stdout); \
450 fputc('\n', stdout); \
451 } \
452 next: \
453 if (sz < 63) \
454 sz++; \
455 else \
456 sz += 9; \
457 } \
458 \
459 fputs(status ? " failed\n" : " ok\n", stdout); \
460 return (status); \
461 }
462
463 #else
464 # define ECB_TEST(PRE, pre)
465 #endif
466
467 /*----- That's all, folks -------------------------------------------------*/
468
469 #ifdef __cplusplus
470 }
471 #endif
472
473 #endif
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)