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Miscellaneous constification.
[u/mdw/catacomb] / ofb-def.h
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79ba130c 1/* -*-c-*-
2 *
4e66da02 3 * $Id: ofb-def.h,v 1.6 2004/04/02 01:03:49 mdw Exp $
79ba130c 4 *
5 * Definitions for output feedback 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/*----- Revision history --------------------------------------------------*
31 *
32 * $Log: ofb-def.h,v $
4e66da02 33 * Revision 1.6 2004/04/02 01:03:49 mdw
34 * Miscellaneous constification.
35 *
4efe32ba 36 * Revision 1.5 2001/06/17 00:10:51 mdw
37 * Typesetting fixes
38 *
360c232e 39 * Revision 1.4 2001/04/03 19:36:36 mdw
40 * Don't use @va_arg@ as an argument to @STORE32@!
41 *
2af20fa2 42 * Revision 1.3 2000/06/17 11:48:02 mdw
43 * Use secure arena for memory allocation. Rearrange setiv slightly.
44 *
4ab1268f 45 * Revision 1.2 1999/12/13 15:34:01 mdw
46 * Add support for seeding from a generic pseudorandom source.
47 *
79ba130c 48 * Revision 1.1 1999/12/10 23:16:40 mdw
49 * Split mode macros into interface and implementation.
50 *
51 */
52
53#ifndef CATACOMB_OFB_DEF_H
54#define CATACOMB_OFB_DEF_H
55
56#ifdef __cplusplus
57 extern "C" {
58#endif
59
60/*----- Header files ------------------------------------------------------*/
61
62#include <stdarg.h>
63#include <string.h>
64
65#include <mLib/bits.h>
66#include <mLib/sub.h>
67
2af20fa2 68#ifndef CATACOMB_ARENA_H
69# include "arena.h"
70#endif
71
79ba130c 72#ifndef CATACOMB_BLKC_H
73# include "blkc.h"
74#endif
75
76#ifndef CATACOMB_GCIPHER_H
77# include "gcipher.h"
78#endif
79
80#ifndef CATACOMB_PARANOIA_H
81# include "paranoia.h"
82#endif
83
84/*----- Macros ------------------------------------------------------------*/
85
86/* --- @OFB_DEF@ --- *
87 *
88 * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
89 *
90 * Use: Creates definitions for output feedback mode.
91 */
92
93#define OFB_DEF(PRE, pre) \
94 \
95/* --- @pre_ofbgetiv@ --- * \
96 * \
97 * Arguments: @const pre_ofbctx *ctx@ = pointer to OFB context block \
4efe32ba 98 * @void *iv@ = pointer to output data block \
79ba130c 99 * \
100 * Returns: --- \
101 * \
102 * Use: Reads the currently set IV. Reading and setting an IV \
103 * is not transparent to the cipher. It will add a `step' \
104 * which must be matched by a similar operation during \
105 * decryption. \
106 */ \
107 \
108void pre##_ofbgetiv(const pre##_ofbctx *ctx, void *iv) \
109{ \
110 octet *p = iv; \
2af20fa2 111 unsigned off = ctx->off; \
112 unsigned rest = PRE##_BLKSZ - off; \
79ba130c 113 memcpy(p, ctx->iv + off, rest); \
114 memcpy(p + rest, ctx->iv, off); \
115} \
116 \
117/* --- @pre_ofbsetiv@ --- * \
118 * \
119 * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
120 * @cnost void *iv@ = pointer to IV to set \
121 * \
122 * Returns: --- \
123 * \
124 * Use: Sets the IV to use for subsequent encryption. \
125 */ \
126 \
127void pre##_ofbsetiv(pre##_ofbctx *ctx, const void *iv) \
128{ \
2af20fa2 129 memcpy(ctx->iv, iv, PRE##_BLKSZ); \
130 ctx->off = PRE##_BLKSZ; \
79ba130c 131} \
132 \
133/* --- @pre_ofbbdry@ --- * \
134 * \
135 * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
136 * \
137 * Returns: --- \
138 * \
139 * Use: Inserts a boundary during encryption. Successful \
140 * decryption must place a similar boundary. \
141 */ \
142 \
143void pre##_ofbbdry(pre##_ofbctx *ctx) \
144{ \
2af20fa2 145 uint32 niv[PRE##_BLKSZ / 4]; \
146 BLKC_LOAD(PRE, niv, ctx->iv); \
147 pre##_eblk(&ctx->ctx, niv, niv); \
148 BLKC_STORE(PRE, ctx->iv, niv); \
149 ctx->off = PRE##_BLKSZ; \
150 BURN(niv); \
79ba130c 151} \
152 \
153/* --- @pre_ofbsetkey@ --- * \
154 * \
155 * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
156 * @const pre_ctx *k@ = pointer to cipher context \
157 * \
158 * Returns: --- \
159 * \
160 * Use: Sets the OFB context to use a different cipher key. \
161 */ \
162 \
163void pre##_ofbsetkey(pre##_ofbctx *ctx, const pre##_ctx *k) \
164{ \
165 ctx->ctx = *k; \
166} \
167 \
168/* --- @pre_ofbinit@ --- * \
169 * \
170 * Arguments: @pre_ofbctx *ctx@ = pointer to cipher context \
171 * @const void *key@ = pointer to the key buffer \
172 * @size_t sz@ = size of the key \
173 * @const void *iv@ = pointer to initialization vector \
174 * \
175 * Returns: --- \
176 * \
177 * Use: Initializes a OFB context ready for use. You should \
178 * ensure that the IV chosen is unique: reusing an IV will \
179 * compromise the security of the entire plaintext. This \
180 * is equivalent to calls to @pre_init@, @pre_ofbsetkey@ \
181 * and @pre_ofbsetiv@. \
182 */ \
183 \
184void pre##_ofbinit(pre##_ofbctx *ctx, \
185 const void *key, size_t sz, \
186 const void *iv) \
187{ \
4e66da02 188 static const octet zero[PRE##_BLKSZ] = { 0 }; \
79ba130c 189 pre##_init(&ctx->ctx, key, sz); \
190 pre##_ofbsetiv(ctx, iv ? iv : zero); \
191} \
192 \
193/* --- @pre_ofbencrypt@ --- * \
194 * \
195 * Arguments: @pre_ofbctx *ctx@ = pointer to OFB context block \
196 * @const void *src@ = pointer to source data \
197 * @void *dest@ = pointer to destination data \
198 * @size_t sz@ = size of block to be encrypted \
199 * \
200 * Returns: --- \
201 * \
202 * Use: Encrypts or decrypts a block with a block cipher in OFB \
203 * mode: encryption and decryption are the same in OFB. \
204 * The destination may be null to just churn the feedback \
205 * round for a bit. The source may be null to use the \
206 * cipher as a random data generator. \
207 */ \
208 \
209void pre##_ofbencrypt(pre##_ofbctx *ctx, \
210 const void *src, void *dest, \
211 size_t sz) \
212{ \
213 const octet *s = src; \
214 octet *d = dest; \
2af20fa2 215 unsigned off = ctx->off; \
79ba130c 216 \
217 /* --- Empty blocks are trivial --- */ \
218 \
219 if (!sz) \
220 return; \
221 \
222 /* --- If I can deal with the block from my buffer, do that --- */ \
223 \
224 if (sz < PRE##_BLKSZ - off) \
225 goto small; \
226 \
227 /* --- Finish off what's left in my buffer --- */ \
228 \
229 if (!d) \
2af20fa2 230 sz -= PRE##_BLKSZ - off; \
79ba130c 231 else { \
232 while (off < PRE##_BLKSZ) { \
233 register octet x = s ? *s++ : 0; \
234 *d++ = ctx->iv[off++] ^ x; \
235 sz--; \
236 } \
237 } \
238 \
239 /* --- Main encryption loop --- */ \
240 \
241 { \
242 uint32 iv[PRE##_BLKSZ / 4]; \
243 BLKC_LOAD(PRE, iv, ctx->iv); \
244 \
245 for (;;) { \
246 pre##_eblk(&ctx->ctx, iv, iv); \
247 if (sz < PRE##_BLKSZ) \
248 break; \
249 if (d) { \
250 if (!s) \
251 BLKC_STORE(PRE, d, iv); \
252 else { \
253 uint32 x[PRE##_BLKSZ / 4]; \
254 BLKC_LOAD(PRE, x, s); \
255 BLKC_XSTORE(PRE, d, iv, x); \
256 s += PRE##_BLKSZ; \
257 } \
258 d += PRE##_BLKSZ; \
259 } \
260 sz -= PRE##_BLKSZ; \
261 } \
262 \
263 BLKC_STORE(PRE, ctx->iv, iv); \
264 off = 0; \
265 } \
266 \
267 /* --- Tidying up the tail end --- */ \
268 \
269 if (sz) { \
270 small: \
271 if (!d) \
272 off += sz; \
273 else do { \
274 register octet x = s ? *s++ : 0; \
275 *d++ = ctx->iv[off++] ^ x; \
276 sz--; \
277 } while (sz); \
278 } \
279 \
280 /* --- Done --- */ \
281 \
282 ctx->off = off; \
283 return; \
284} \
285 \
286/* --- Generic cipher interface --- */ \
287 \
288static const gcipher_ops gops; \
289 \
290typedef struct gctx { \
291 gcipher c; \
292 pre##_ofbctx k; \
293} gctx; \
294 \
295static gcipher *ginit(const void *k, size_t sz) \
296{ \
2af20fa2 297 gctx *g = S_CREATE(gctx); \
79ba130c 298 g->c.ops = &gops; \
299 pre##_ofbinit(&g->k, k, sz, 0); \
300 return (&g->c); \
301} \
302 \
303static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \
304{ \
305 gctx *g = (gctx *)c; \
306 pre##_ofbencrypt(&g->k, s, t, sz); \
307} \
308 \
309static void gdestroy(gcipher *c) \
310{ \
311 gctx *g = (gctx *)c; \
2af20fa2 312 BURN(*g); \
313 S_DESTROY(g); \
79ba130c 314} \
315 \
316static void gsetiv(gcipher *c, const void *iv) \
317{ \
318 gctx *g = (gctx *)c; \
319 pre##_ofbsetiv(&g->k, iv); \
320} \
321 \
322static void gbdry(gcipher *c) \
323{ \
324 gctx *g = (gctx *)c; \
325 pre##_ofbbdry(&g->k); \
326} \
327 \
328static const gcipher_ops gops = { \
2af20fa2 329 &pre##_ofb, \
79ba130c 330 gencrypt, gencrypt, gdestroy, gsetiv, gbdry \
331}; \
332 \
333const gccipher pre##_ofb = { \
2af20fa2 334 #pre "-ofb", pre##_keysz, PRE##_BLKSZ, \
79ba130c 335 ginit \
336}; \
337 \
338/* --- Generic random number generator interface --- */ \
339 \
340typedef struct grctx { \
341 grand r; \
342 pre##_ofbctx k; \
343} grctx; \
344 \
345static void grdestroy(grand *r) \
346{ \
347 grctx *g = (grctx *)r; \
2af20fa2 348 BURN(*g); \
349 S_DESTROY(g); \
79ba130c 350} \
351 \
352static int grmisc(grand *r, unsigned op, ...) \
353{ \
354 grctx *g = (grctx *)r; \
355 va_list ap; \
356 int rc = 0; \
360c232e 357 uint32 i; \
79ba130c 358 octet buf[PRE##_BLKSZ]; \
359 va_start(ap, op); \
360 \
361 switch (op) { \
362 case GRAND_CHECK: \
363 switch (va_arg(ap, unsigned)) { \
364 case GRAND_CHECK: \
365 case GRAND_SEEDINT: \
366 case GRAND_SEEDUINT32: \
367 case GRAND_SEEDBLOCK: \
4ab1268f 368 case GRAND_SEEDRAND: \
79ba130c 369 rc = 1; \
370 break; \
371 default: \
372 rc = 0; \
373 break; \
374 } \
375 break; \
376 case GRAND_SEEDINT: \
377 memset(buf, 0, sizeof(buf)); \
360c232e 378 i = va_arg(ap, unsigned); \
379 STORE32(buf, i); \
79ba130c 380 pre##_ofbsetiv(&g->k, buf); \
381 break; \
382 case GRAND_SEEDUINT32: \
383 memset(buf, 0, sizeof(buf)); \
360c232e 384 i = va_arg(ap, uint32); \
385 STORE32(buf, i); \
79ba130c 386 pre##_ofbsetiv(&g->k, buf); \
387 break; \
388 case GRAND_SEEDBLOCK: { \
389 const void *p = va_arg(ap, const void *); \
390 size_t sz = va_arg(ap, size_t); \
391 if (sz < sizeof(buf)) { \
392 memset(buf, 0, sizeof(buf)); \
393 memcpy(buf, p, sz); \
394 p = buf; \
395 } \
396 pre##_ofbsetiv(&g->k, p); \
397 } break; \
4ab1268f 398 case GRAND_SEEDRAND: { \
399 grand *rr = va_arg(ap, grand *); \
400 rr->ops->fill(rr, buf, sizeof(buf)); \
401 pre##_ofbsetiv(&g->k, buf); \
402 } break; \
403 default: \
404 GRAND_BADOP; \
405 break; \
79ba130c 406 } \
407 \
408 va_end(ap); \
409 return (rc); \
410} \
411 \
412static octet grbyte(grand *r) \
413{ \
414 grctx *g = (grctx *)r; \
415 octet o; \
416 pre##_ofbencrypt(&g->k, 0, &o, 1); \
417 return (o); \
418} \
419 \
420static uint32 grword(grand *r) \
421{ \
422 grctx *g = (grctx *)r; \
423 octet b[4]; \
424 pre##_ofbencrypt(&g->k, 0, b, sizeof(b)); \
425 return (LOAD32(b)); \
426} \
427 \
428static void grfill(grand *r, void *p, size_t sz) \
429{ \
430 grctx *g = (grctx *)r; \
431 pre##_ofbencrypt(&g->k, 0, p, sz); \
432} \
433 \
434static const grand_ops grops = { \
435 #pre "-ofb", \
2af20fa2 436 GRAND_CRYPTO, 0, \
79ba130c 437 grmisc, grdestroy, \
438 grword, grbyte, grword, grand_range, grfill \
439}; \
440 \
441/* --- @pre_ofbrand@ --- * \
442 * \
443 * Arguments: @const void *k@ = pointer to key material \
444 * @size_t sz@ = size of key material \
445 * \
446 * Returns: Pointer to generic random number generator interface. \
447 * \
448 * Use: Creates a random number interface wrapper around an \
449 * OFB-mode block cipher. \
450 */ \
451 \
452grand *pre##_ofbrand(const void *k, size_t sz) \
453{ \
2af20fa2 454 grctx *g = S_CREATE(grctx); \
79ba130c 455 g->r.ops = &grops; \
456 pre##_ofbinit(&g->k, k, sz, 0); \
457 return (&g->r); \
458} \
459 \
460OFB_TEST(PRE, pre)
461
462/*----- Test rig ----------------------------------------------------------*/
463
464#ifdef TEST_RIG
465
466#include <stdio.h>
467
468#include "daftstory.h"
469
470/* --- @OFB_TEST@ --- *
471 *
472 * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
473 *
474 * Use: Standard test rig for OFB functions.
475 */
476
477#define OFB_TEST(PRE, pre) \
478 \
479/* --- Initial plaintext for the test --- */ \
480 \
481static const octet text[] = TEXT; \
482 \
483/* --- Key and IV to use --- */ \
484 \
485static const octet key[] = KEY; \
486static const octet iv[] = IV; \
487 \
488/* --- Buffers for encryption and decryption output --- */ \
489 \
490static octet ct[sizeof(text)]; \
491static octet pt[sizeof(text)]; \
492 \
493static void hexdump(const octet *p, size_t sz) \
494{ \
495 const octet *q = p + sz; \
496 for (sz = 0; p < q; p++, sz++) { \
497 printf("%02x", *p); \
498 if ((sz + 1) % PRE##_BLKSZ == 0) \
499 putchar(':'); \
500 } \
501} \
502 \
503int main(void) \
504{ \
505 size_t sz = 0, rest; \
506 pre##_ofbctx ctx; \
507 int status = 0; \
508 int done = 0; \
509 pre##_ctx k; \
510 \
511 size_t keysz = PRE##_KEYSZ ? \
512 PRE##_KEYSZ : strlen((const char *)key); \
513 \
514 fputs(#pre "-ofb: ", stdout); \
515 \
516 pre##_init(&k, key, keysz); \
517 pre##_ofbsetkey(&ctx, &k); \
518 \
519 while (sz <= sizeof(text)) { \
520 rest = sizeof(text) - sz; \
521 memcpy(ct, text, sizeof(text)); \
522 pre##_ofbsetiv(&ctx, iv); \
523 pre##_ofbencrypt(&ctx, ct, ct, sz); \
524 pre##_ofbencrypt(&ctx, ct + sz, ct + sz, rest); \
525 memcpy(pt, ct, sizeof(text)); \
526 pre##_ofbsetiv(&ctx, iv); \
527 pre##_ofbencrypt(&ctx, pt, pt, rest); \
528 pre##_ofbencrypt(&ctx, pt + rest, pt + rest, sz); \
529 if (memcmp(pt, text, sizeof(text)) == 0) { \
530 done++; \
531 if (sizeof(text) < 40 || done % 8 == 0) \
532 fputc('.', stdout); \
533 if (done % 480 == 0) \
534 fputs("\n\t", stdout); \
535 fflush(stdout); \
536 } else { \
537 printf("\nError (sz = %lu)\n", (unsigned long)sz); \
538 status = 1; \
539 printf("\tplaintext = "); hexdump(text, sz); \
540 printf(", "); hexdump(text + sz, rest); \
541 fputc('\n', stdout); \
542 printf("\tciphertext = "); hexdump(ct, sz); \
543 printf(", "); hexdump(ct + sz, rest); \
544 fputc('\n', stdout); \
545 printf("\trecovered text = "); hexdump(pt, sz); \
546 printf(", "); hexdump(pt + sz, rest); \
547 fputc('\n', stdout); \
548 fputc('\n', stdout); \
549 } \
550 if (sz < 63) \
551 sz++; \
552 else \
553 sz += 9; \
554 } \
555 \
556 fputs(status ? " failed\n" : " ok\n", stdout); \
557 return (status); \
558}
559
560#else
561# define OFB_TEST(PRE, pre)
562#endif
563
564/*----- That's all, folks -------------------------------------------------*/
565
566#ifdef __cplusplus
567 }
568#endif
569
570#endif
Catacomb cryptographic library (downstream of http://git.distorted.org.uk/~mdw/catacomb/)