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math/mpreduce.h: Missing include files.
[u/mdw/catacomb] / symm / cbc-def.h
1 /* -*-c-*-
2 *
3 * Definitions for cipher block chaining mode
4 *
5 * (c) 1999 Straylight/Edgeware
6 */
7
8 /*----- Licensing notice --------------------------------------------------*
9 *
10 * This file is part of Catacomb.
11 *
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.
16 *
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.
21 *
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,
25 * MA 02111-1307, USA.
26 */
27
28 #ifndef CATACOMB_CBC_DEF_H
29 #define CATACOMB_CBC_DEF_H
30
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34
35 /*----- Header files ------------------------------------------------------*/
36
37 #include <string.h>
38
39 #include <mLib/bits.h>
40 #include <mLib/sub.h>
41
42 #ifndef CATACOMB_ARENA_H
43 # include "arena.h"
44 #endif
45
46 #ifndef CATACOMB_BLKC_H
47 # include "blkc.h"
48 #endif
49
50 #ifndef CATACOMB_GCIPHER_H
51 # include "gcipher.h"
52 #endif
53
54 #ifndef CATACOMB_PARANOIA_H
55 # include "paranoia.h"
56 #endif
57
58 /*----- Macros ------------------------------------------------------------*/
59
60 /* --- @CBC_DEF@ --- *
61 *
62 * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
63 *
64 * Use: Creates an implementation for CBC stealing mode.
65 */
66
67 #define CBC_DEF(PRE, pre) \
68 \
69 /* --- @pre_cbcgetiv@ --- * \
70 * \
71 * Arguments: @const pre_cbcctx *ctx@ = pointer to CBC context block \
72 * @void *iv@ = pointer to output data block \
73 * \
74 * Returns: --- \
75 * \
76 * Use: Reads the currently set IV. Reading and setting an IV \
77 * is transparent to the CBC encryption or decryption \
78 * process. \
79 */ \
80 \
81 void pre##_cbcgetiv(const pre##_cbcctx *ctx, void *iv) \
82 { \
83 BLKC_STORE(PRE, iv, ctx->iv); \
84 } \
85 \
86 /* --- @pre_cbcsetiv@ --- * \
87 * \
88 * Arguments: @pre_cbcctx *ctx@ = pointer to CBC context block \
89 * @cnost void *iv@ = pointer to IV to set \
90 * \
91 * Returns: --- \
92 * \
93 * Use: Sets the IV to use for subsequent encryption. \
94 */ \
95 \
96 void pre##_cbcsetiv(pre##_cbcctx *ctx, const void *iv) \
97 { \
98 BLKC_LOAD(PRE, ctx->iv, iv); \
99 } \
100 \
101 /* --- @pre_cbcsetkey@ --- * \
102 * \
103 * Arguments: @pre_cbcctx *ctx@ = pointer to CBC context block \
104 * @const pre_ctx *k@ = pointer to cipher context \
105 * \
106 * Returns: --- \
107 * \
108 * Use: Sets the CBC context to use a different cipher key. \
109 */ \
110 \
111 void pre##_cbcsetkey(pre##_cbcctx *ctx, const pre##_ctx *k) \
112 { \
113 ctx->ctx = *k; \
114 } \
115 \
116 /* --- @pre_cbcinit@ --- * \
117 * \
118 * Arguments: @pre_cbcctx *ctx@ = pointer to cipher context \
119 * @const void *key@ = pointer to the key buffer \
120 * @size_t sz@ = size of the key \
121 * @const void *iv@ = pointer to initialization vector \
122 * \
123 * Returns: --- \
124 * \
125 * Use: Initializes a CBC context ready for use. The @iv@ \
126 * argument may be passed as a null pointer to set a zero \
127 * IV. Apart from that, this call is equivalent to calls \
128 * to @pre_init@, @pre_cbcsetkey@ and @pre_cbcsetiv@. \
129 */ \
130 \
131 void pre##_cbcinit(pre##_cbcctx *ctx, \
132 const void *key, size_t sz, \
133 const void *iv) \
134 { \
135 static const octet zero[PRE##_BLKSZ] = { 0 }; \
136 pre##_init(&ctx->ctx, key, sz); \
137 BLKC_LOAD(PRE, ctx->iv, iv ? iv : zero); \
138 } \
139 \
140 /* --- @pre_cbcencrypt@ --- * \
141 * \
142 * Arguments: @pre_cbcctx *ctx@ = pointer to CBC context block \
143 * @const void *src@ = pointer to source data \
144 * @void *dest@ = pointer to destination data \
145 * @size_t sz@ = size of block to be encrypted \
146 * \
147 * Returns: --- \
148 * \
149 * Use: Encrypts a block with a block cipher in CBC mode, with \
150 * ciphertext stealing and other clever tricks. \
151 * Essentially, data can be encrypted in arbitrary sized \
152 * chunks, although decryption must use the same chunks. \
153 */ \
154 \
155 void pre##_cbcencrypt(pre##_cbcctx *ctx, \
156 const void *src, void *dest, \
157 size_t sz) \
158 { \
159 const octet *s = src; \
160 octet *d = dest; \
161 \
162 /* --- Empty blocks are trivial --- */ \
163 \
164 if (!sz) \
165 return; \
166 \
167 /* --- Extra magical case for a short block --- * \
168 * \
169 * Encrypt the IV, then exclusive-or the plaintext with the octets \
170 * of the encrypted IV, shifting ciphertext octets in instead. This \
171 * basically switches over to CFB. \
172 */ \
173 \
174 if (sz < PRE##_BLKSZ) { \
175 octet b[PRE##_BLKSZ]; \
176 unsigned i; \
177 \
178 pre##_eblk(&ctx->ctx, ctx->iv, ctx->iv); \
179 BLKC_STORE(PRE, b, ctx->iv); \
180 if (d) { \
181 for (i = 0; i < sz; i++) \
182 d[i] = b[i] ^ (s ? s[i] : 0); \
183 } \
184 memmove(b, b + sz, PRE##_BLKSZ - sz); \
185 memcpy(b + PRE##_BLKSZ - sz, d, sz); \
186 BLKC_LOAD(PRE, ctx->iv, b); \
187 return; \
188 } \
189 \
190 /* --- Do the main chunk of encryption --- * \
191 * \
192 * This will do the whole lot if it's a whole number of blocks. For \
193 * each block, XOR it with the previous ciphertext in @iv@, encrypt, \
194 * and keep a copy of the ciphertext for the next block. \
195 */ \
196 \
197 while (sz >= 2 * PRE##_BLKSZ || sz == PRE##_BLKSZ) { \
198 if (s) { \
199 BLKC_XLOAD(PRE, ctx->iv, s); \
200 s += PRE##_BLKSZ; \
201 } \
202 pre##_eblk(&ctx->ctx, ctx->iv, ctx->iv); \
203 if (d) { \
204 BLKC_STORE(PRE, d, ctx->iv); \
205 d += PRE##_BLKSZ; \
206 } \
207 sz -= PRE##_BLKSZ; \
208 } \
209 \
210 /* --- Do the tail-end block and bit-left-over --- * \
211 * \
212 * This isn't very efficient. That shouldn't matter much. \
213 */ \
214 \
215 if (sz) { \
216 octet b[PRE##_BLKSZ]; \
217 unsigned i; \
218 \
219 /* --- Let @sz@ be the size of the partial block --- */ \
220 \
221 sz -= PRE##_BLKSZ; \
222 \
223 /* --- First stage --- * \
224 * \
225 * XOR the complete block with the current IV, and encrypt it. The \
226 * first part of the result is the partial ciphertext block. Don't \
227 * write that out yet, because I've not read the partial plaintext \
228 * block. \
229 */ \
230 \
231 if (s) BLKC_XLOAD(PRE, ctx->iv, s); \
232 pre##_eblk(&ctx->ctx, ctx->iv, ctx->iv); \
233 BLKC_STORE(PRE, b, ctx->iv); \
234 \
235 /* --- Second stage --- * \
236 * \
237 * Now XOR in the partial plaintext block, writing out the \
238 * ciphertext as I go. Then encrypt, and write the complete \
239 * ciphertext block. \
240 */ \
241 \
242 if (s) s += PRE##_BLKSZ; \
243 if (d) d += PRE##_BLKSZ; \
244 for (i = 0; i < sz; i++) { \
245 register octet x = b[i]; \
246 if (s) b[i] ^= s[i]; \
247 if (d) d[i] = x; \
248 } \
249 BLKC_LOAD(PRE, ctx->iv, b); \
250 pre##_eblk(&ctx->ctx, ctx->iv, ctx->iv); \
251 if (d) BLKC_STORE(PRE, d - PRE##_BLKSZ, ctx->iv); \
252 } \
253 \
254 /* --- Done --- */ \
255 \
256 return; \
257 } \
258 \
259 /* --- @pre_cbcdecrypt@ --- * \
260 * \
261 * Arguments: @pre_cbcctx *ctx@ = pointer to CBC context block \
262 * @const void *src@ = pointer to source data \
263 * @void *dest@ = pointer to destination data \
264 * @size_t sz@ = size of block to be encrypted \
265 * \
266 * Returns: --- \
267 * \
268 * Use: Decrypts a block with a block cipher in CBC mode, with \
269 * ciphertext stealing and other clever tricks. \
270 * Essentially, data can be encrypted in arbitrary sized \
271 * chunks, although decryption must use the same chunks. \
272 */ \
273 \
274 void pre##_cbcdecrypt(pre##_cbcctx *ctx, \
275 const void *src, void *dest, \
276 size_t sz) \
277 { \
278 const octet *s = src; \
279 octet *d = dest; \
280 \
281 /* --- Empty blocks are trivial --- */ \
282 \
283 if (!sz) \
284 return; \
285 \
286 /* --- Extra magical case for a short block --- * \
287 * \
288 * Encrypt the IV, then exclusive-or the ciphertext with the octets \
289 * of the encrypted IV, shifting ciphertext octets in instead. This \
290 * basically switches over to CFB. \
291 */ \
292 \
293 if (sz < PRE##_BLKSZ) { \
294 octet b[PRE##_BLKSZ], c[PRE##_BLKSZ]; \
295 unsigned i; \
296 \
297 pre##_eblk(&ctx->ctx, ctx->iv, ctx->iv); \
298 BLKC_STORE(PRE, b, ctx->iv); \
299 for (i = 0; i < sz; i++) { \
300 register octet x = s[i]; \
301 d[i] = b[i] ^ x; \
302 c[i] = x; \
303 } \
304 memmove(b, b + sz, PRE##_BLKSZ - sz); \
305 memcpy(b + PRE##_BLKSZ - sz, c, sz); \
306 BLKC_LOAD(PRE, ctx->iv, b); \
307 return; \
308 } \
309 \
310 /* --- Do the main chunk of decryption --- * \
311 * \
312 * This will do the whole lot if it's a whole number of blocks. For \
313 * each block, decrypt, XOR it with the previous ciphertext in @iv@, \
314 * and keep a copy of the ciphertext for the next block. \
315 */ \
316 \
317 while (sz >= 2 * PRE##_BLKSZ || sz == PRE##_BLKSZ) { \
318 uint32 b[PRE##_BLKSZ / 4], niv[PRE##_BLKSZ / 4]; \
319 BLKC_LOAD(PRE, niv, s); \
320 pre##_dblk(&ctx->ctx, niv, b); \
321 BLKC_XSTORE(PRE, d, b, ctx->iv); \
322 BLKC_MOVE(PRE, ctx->iv, niv); \
323 s += PRE##_BLKSZ; \
324 d += PRE##_BLKSZ; \
325 sz -= PRE##_BLKSZ; \
326 } \
327 \
328 /* --- Do the tail-end block and bit-left-over --- * \
329 * \
330 * This isn't very efficient. That shouldn't matter much. \
331 */ \
332 \
333 if (sz) { \
334 octet b[PRE##_BLKSZ]; \
335 uint32 bk[PRE##_BLKSZ / 4], niv[PRE##_BLKSZ / 4]; \
336 unsigned i; \
337 \
338 /* --- Let @sz@ be the size of the partial block --- */ \
339 \
340 sz -= PRE##_BLKSZ; \
341 \
342 /* --- First stage --- * \
343 * \
344 * Take the complete ciphertext block, and decrypt it. This block \
345 * is carried over for the next encryption operation. \
346 */ \
347 \
348 BLKC_LOAD(PRE, niv, s); \
349 pre##_dblk(&ctx->ctx, niv, bk); \
350 \
351 /* --- Second stage --- * \
352 * \
353 * XORing the first few bytes of this with the partial ciphertext \
354 * block recovers the partial plaintext block. At the same time, \
355 * write the partial ciphertext block's contents in ready for stage \
356 * three. \
357 */ \
358 \
359 BLKC_STORE(PRE, b, bk); \
360 s += PRE##_BLKSZ; \
361 d += PRE##_BLKSZ; \
362 for (i = 0; i < sz; i++) { \
363 register octet x = s[i]; \
364 d[i] = b[i] ^ x; \
365 b[i] = x; \
366 } \
367 \
368 /* --- Third stage --- * \
369 * \
370 * Decrypt the block we've got left, and XOR with the initial IV to \
371 * recover the complete plaintext block. \
372 */ \
373 \
374 BLKC_LOAD(PRE, bk, b); \
375 pre##_dblk(&ctx->ctx, bk, bk); \
376 BLKC_XSTORE(PRE, d - PRE##_BLKSZ, bk, ctx->iv); \
377 BLKC_MOVE(PRE, ctx->iv, niv); \
378 } \
379 \
380 /* --- Done --- */ \
381 \
382 return; \
383 } \
384 \
385 /* --- Generic cipher interface --- */ \
386 \
387 static const gcipher_ops gops; \
388 \
389 typedef struct gctx { \
390 gcipher c; \
391 pre##_cbcctx k; \
392 } gctx; \
393 \
394 static gcipher *ginit(const void *k, size_t sz) \
395 { \
396 gctx *g = S_CREATE(gctx); \
397 g->c.ops = &gops; \
398 pre##_cbcinit(&g->k, k, sz, 0); \
399 return (&g->c); \
400 } \
401 \
402 static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \
403 { \
404 gctx *g = (gctx *)c; \
405 pre##_cbcencrypt(&g->k, s, t, sz); \
406 } \
407 \
408 static void gdecrypt(gcipher *c, const void *s, void *t, size_t sz) \
409 { \
410 gctx *g = (gctx *)c; \
411 pre##_cbcdecrypt(&g->k, s, t, sz); \
412 } \
413 \
414 static void gdestroy(gcipher *c) \
415 { \
416 gctx *g = (gctx *)c; \
417 BURN(*g); \
418 S_DESTROY(g); \
419 } \
420 \
421 static void gsetiv(gcipher *c, const void *iv) \
422 { \
423 gctx *g = (gctx *)c; \
424 pre##_cbcsetiv(&g->k, iv); \
425 } \
426 \
427 static const gcipher_ops gops = { \
428 &pre##_cbc, \
429 gencrypt, gdecrypt, gdestroy, gsetiv, 0 \
430 }; \
431 \
432 const gccipher pre##_cbc = { \
433 #pre "-cbc", pre##_keysz, PRE##_BLKSZ, \
434 ginit \
435 }; \
436 \
437 CBC_TEST(PRE, pre)
438
439 /*----- Test rig ----------------------------------------------------------*/
440
441 #ifdef TEST_RIG
442
443 #include <stdio.h>
444
445 #include "daftstory.h"
446
447 /* --- @CBC_TEST@ --- *
448 *
449 * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
450 *
451 * Use: Standard test rig for CBC functions.
452 */
453
454 #define CBC_TEST(PRE, pre) \
455 \
456 /* --- Initial plaintext for the test --- */ \
457 \
458 static const octet text[] = TEXT; \
459 \
460 /* --- Key and IV to use --- */ \
461 \
462 static const octet key[] = KEY; \
463 static const octet iv[] = IV; \
464 \
465 /* --- Buffers for encryption and decryption output --- */ \
466 \
467 static octet ct[sizeof(text)]; \
468 static octet pt[sizeof(text)]; \
469 \
470 static void hexdump(const octet *p, size_t sz) \
471 { \
472 const octet *q = p + sz; \
473 for (sz = 0; p < q; p++, sz++) { \
474 printf("%02x", *p); \
475 if ((sz + 1) % PRE##_BLKSZ == 0) \
476 putchar(':'); \
477 } \
478 } \
479 \
480 int main(void) \
481 { \
482 size_t sz = 0, rest; \
483 pre##_cbcctx ctx; \
484 pre##_ctx k; \
485 int status = 0; \
486 int done = 0; \
487 \
488 size_t keysz = PRE##_KEYSZ ? \
489 PRE##_KEYSZ : strlen((const char *)key); \
490 \
491 fputs(#pre "-cbc: ", stdout); \
492 \
493 pre##_init(&k, key, keysz); \
494 pre##_cbcsetkey(&ctx, &k); \
495 \
496 while (sz <= sizeof(text)) { \
497 rest = sizeof(text) - sz; \
498 memcpy(ct, text, sizeof(text)); \
499 pre##_cbcsetiv(&ctx, iv); \
500 pre##_cbcencrypt(&ctx, ct, ct, sz); \
501 pre##_cbcencrypt(&ctx, ct + sz, ct + sz, rest); \
502 memcpy(pt, ct, sizeof(text)); \
503 pre##_cbcsetiv(&ctx, iv); \
504 pre##_cbcdecrypt(&ctx, pt, pt, sz); \
505 pre##_cbcdecrypt(&ctx, pt + sz, pt + sz, rest); \
506 if (memcmp(pt, text, sizeof(text)) == 0) { \
507 done++; \
508 if (sizeof(text) < 40 || done % 8 == 0) \
509 fputc('.', stdout); \
510 if (done % 480 == 0) \
511 fputs("\n\t", stdout); \
512 fflush(stdout); \
513 } else { \
514 printf("\nError (sz = %lu)\n", (unsigned long)sz); \
515 status = 1; \
516 printf("\tplaintext = "); hexdump(text, sz); \
517 printf(", "); hexdump(text + sz, rest); \
518 fputc('\n', stdout); \
519 printf("\tciphertext = "); hexdump(ct, sz); \
520 printf(", "); hexdump(ct + sz, rest); \
521 fputc('\n', stdout); \
522 printf("\trecovered text = "); hexdump(pt, sz); \
523 printf(", "); hexdump(pt + sz, rest); \
524 fputc('\n', stdout); \
525 fputc('\n', stdout); \
526 } \
527 if (sz < 63) \
528 sz++; \
529 else \
530 sz += 9; \
531 } \
532 \
533 fputs(status ? " failed\n" : " ok\n", stdout); \
534 return (status); \
535 }
536
537 #else
538 # define CBC_TEST(PRE, pre)
539 #endif
540
541 /*----- That's all, folks -------------------------------------------------*/
542
543 #ifdef __cplusplus
544 }
545 #endif
546
547 #endif
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)