35d66180 |
1 | /* -*-c-*- |
2 | * |
4e66da02 |
3 | * $Id: counter-def.h,v 1.3 2004/04/02 01:03:49 mdw Exp $ |
35d66180 |
4 | * |
5 | * Block cipher counter mode (or long cycle mode) |
6 | * |
7 | * (c) 2000 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: counter-def.h,v $ |
4e66da02 |
33 | * Revision 1.3 2004/04/02 01:03:49 mdw |
34 | * Miscellaneous constification. |
35 | * |
4efe32ba |
36 | * Revision 1.2 2001/06/17 00:10:51 mdw |
37 | * Typesetting fixes |
38 | * |
35d66180 |
39 | * Revision 1.1 2000/06/17 10:51:42 mdw |
40 | * Counter mode ciphers and pseudo-random generator. |
41 | * |
42 | */ |
43 | |
44 | #ifndef CATACOMB_COUNTER_DEF_H |
45 | #define CATACOMB_COUNTER_DEF_H |
46 | |
47 | #ifdef __cplusplus |
48 | extern "C" { |
49 | #endif |
50 | |
51 | /*----- Header files ------------------------------------------------------*/ |
52 | |
53 | #include <stdarg.h> |
54 | #include <string.h> |
55 | |
56 | #include <mLib/bits.h> |
57 | #include <mLib/sub.h> |
58 | |
59 | #ifndef CATACOMB_ARENA_H |
60 | # include "arena.h" |
61 | #endif |
62 | |
63 | #ifndef CATACOMB_BLKC_H |
64 | # include "blkc.h" |
65 | #endif |
66 | |
67 | #ifndef CATACOMB_GCIPHER_H |
68 | # include "gcipher.h" |
69 | #endif |
70 | |
71 | #ifndef CATACOMB_PARANOIA_H |
72 | # include "paranoia.h" |
73 | #endif |
74 | |
75 | /*----- Macros ------------------------------------------------------------*/ |
76 | |
77 | /* --- @COUNTER_DEF@ --- * |
78 | * |
79 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher |
80 | * |
81 | * Use: Creates definitions for counter mode. |
82 | */ |
83 | |
84 | #define COUNTER_DEF(PRE, pre) \ |
85 | \ |
86 | /* --- @pre_countergetiv@ --- * \ |
87 | * \ |
88 | * Arguments: @const pre_counterctx *ctx@ = pointer to counter \ |
89 | * context \ |
4efe32ba |
90 | * @void *iv@ = pointer to output data block \ |
35d66180 |
91 | * \ |
92 | * Returns: --- \ |
93 | * \ |
94 | * Use: Reads the currently set IV. Reading and setting an IV \ |
95 | * is not transparent to the cipher. It will add a `step' \ |
96 | * which must be matched by a similar operation during \ |
97 | * decryption. \ |
98 | */ \ |
99 | \ |
100 | void pre##_countergetiv(const pre##_counterctx *ctx, void *iv) \ |
101 | { \ |
102 | BLKC_STORE(PRE, iv, ctx->n); \ |
103 | } \ |
104 | \ |
105 | /* --- @pre_countersetiv@ --- * \ |
106 | * \ |
107 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ |
108 | * @cnost void *iv@ = pointer to IV to set \ |
109 | * \ |
110 | * Returns: --- \ |
111 | * \ |
112 | * Use: Sets the IV to use for subsequent encryption. \ |
113 | */ \ |
114 | \ |
115 | void pre##_countersetiv(pre##_counterctx *ctx, const void *iv) \ |
116 | { \ |
117 | BLKC_LOAD(PRE, ctx->n, iv); \ |
118 | ctx->off = PRE##_BLKSZ; \ |
119 | } \ |
120 | \ |
121 | /* --- @pre_counterbdry@ --- * \ |
122 | * \ |
123 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ |
124 | * \ |
125 | * Returns: --- \ |
126 | * \ |
127 | * Use: Inserts a boundary during encryption. Successful \ |
128 | * decryption must place a similar boundary. \ |
129 | */ \ |
130 | \ |
131 | void pre##_counterbdry(pre##_counterctx *ctx) \ |
132 | { \ |
133 | BLKC_STEP(PRE, ctx->n); \ |
134 | ctx->off = PRE##_BLKSZ; \ |
135 | } \ |
136 | \ |
137 | /* --- @pre_countersetkey@ --- * \ |
138 | * \ |
139 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ |
140 | * @const pre_ctx *k@ = pointer to cipher context \ |
141 | * \ |
142 | * Returns: --- \ |
143 | * \ |
144 | * Use: Sets the counter context to use a different cipher key. \ |
145 | */ \ |
146 | \ |
147 | void pre##_countersetkey(pre##_counterctx *ctx, const pre##_ctx *k) \ |
148 | { \ |
149 | ctx->ctx = *k; \ |
150 | } \ |
151 | \ |
152 | /* --- @pre_counterinit@ --- * \ |
153 | * \ |
154 | * Arguments: @pre_counterctx *ctx@ = pointer to cipher context \ |
155 | * @const void *key@ = pointer to the key buffer \ |
156 | * @size_t sz@ = size of the key \ |
157 | * @const void *iv@ = pointer to initialization vector \ |
158 | * \ |
159 | * Returns: --- \ |
160 | * \ |
161 | * Use: Initializes a counter context ready for use. You \ |
162 | * should ensure that the IV chosen is unique: reusing an \ |
163 | * IV will compromise the security of the entire \ |
164 | * plaintext. This is equivalent to calls to @pre_init@, \ |
165 | * @pre_countersetkey@ and @pre_countersetiv@. \ |
166 | */ \ |
167 | \ |
168 | void pre##_counterinit(pre##_counterctx *ctx, \ |
169 | const void *key, size_t sz, \ |
170 | const void *iv) \ |
171 | { \ |
4e66da02 |
172 | static const octet zero[PRE##_BLKSZ] = { 0 }; \ |
35d66180 |
173 | pre##_init(&ctx->ctx, key, sz); \ |
174 | pre##_countersetiv(ctx, iv ? iv : zero); \ |
175 | } \ |
176 | \ |
177 | /* --- @pre_counterencrypt@ --- * \ |
178 | * \ |
179 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ |
180 | * @const void *src@ = pointer to source data \ |
181 | * @void *dest@ = pointer to destination data \ |
182 | * @size_t sz@ = size of block to be encrypted \ |
183 | * \ |
184 | * Returns: --- \ |
185 | * \ |
186 | * Use: Encrypts or decrypts a block with a block cipher in \ |
187 | * counter mode: encryption and decryption are the same in \ |
188 | * counter. The destination may be null to just churn the \ |
189 | * feedback round for a bit. The source may be null to \ |
190 | * use the cipher as a random data generator. \ |
191 | */ \ |
192 | \ |
193 | void pre##_counterencrypt(pre##_counterctx *ctx, \ |
194 | const void *src, void *dest, \ |
195 | size_t sz) \ |
196 | { \ |
197 | const octet *s = src; \ |
198 | octet *d = dest; \ |
199 | unsigned off = ctx->off; \ |
200 | \ |
201 | /* --- Empty blocks are trivial --- */ \ |
202 | \ |
203 | if (!sz) \ |
204 | return; \ |
205 | \ |
206 | /* --- If I can deal with the block from my buffer, do that --- */ \ |
207 | \ |
208 | if (sz < PRE##_BLKSZ - off) \ |
209 | goto small; \ |
210 | \ |
211 | /* --- Finish off what's left in my buffer --- */ \ |
212 | \ |
213 | if (!d) \ |
214 | sz -= PRE##_BLKSZ - off; \ |
215 | else { \ |
216 | while (off < PRE##_BLKSZ) { \ |
217 | register octet x = s ? *s++ : 0; \ |
218 | *d++ = ctx->buf[off++] ^ x; \ |
219 | sz--; \ |
220 | } \ |
221 | } \ |
222 | \ |
223 | /* --- Main encryption loop --- */ \ |
224 | \ |
225 | { \ |
226 | uint32 n[PRE##_BLKSZ / 4]; \ |
227 | \ |
228 | for (;;) { \ |
229 | pre##_eblk(&ctx->ctx, ctx->n, n); \ |
230 | BLKC_STEP(PRE, ctx->n); \ |
231 | if (sz < PRE##_BLKSZ) \ |
232 | break; \ |
233 | if (d) { \ |
234 | if (!s) \ |
235 | BLKC_STORE(PRE, d, n); \ |
236 | else { \ |
237 | uint32 x[PRE##_BLKSZ / 4]; \ |
238 | BLKC_LOAD(PRE, x, s); \ |
239 | BLKC_XSTORE(PRE, d, n, x); \ |
240 | s += PRE##_BLKSZ; \ |
241 | } \ |
242 | d += PRE##_BLKSZ; \ |
243 | } \ |
244 | sz -= PRE##_BLKSZ; \ |
245 | } \ |
246 | \ |
247 | BLKC_STORE(PRE, ctx->buf, n); \ |
248 | off = 0; \ |
249 | } \ |
250 | \ |
251 | /* --- Tidying up the tail end --- */ \ |
252 | \ |
253 | if (sz) { \ |
254 | small: \ |
255 | if (!d) \ |
256 | off += sz; \ |
257 | else do { \ |
258 | register octet x = s ? *s++ : 0; \ |
259 | *d++ = ctx->buf[off++] ^ x; \ |
260 | sz--; \ |
261 | } while (sz); \ |
262 | } \ |
263 | \ |
264 | /* --- Done --- */ \ |
265 | \ |
266 | ctx->off = off; \ |
267 | return; \ |
268 | } \ |
269 | \ |
270 | /* --- Generic cipher interface --- */ \ |
271 | \ |
272 | static const gcipher_ops gops; \ |
273 | \ |
274 | typedef struct gctx { \ |
275 | gcipher c; \ |
276 | pre##_counterctx k; \ |
277 | } gctx; \ |
278 | \ |
279 | static gcipher *ginit(const void *k, size_t sz) \ |
280 | { \ |
281 | gctx *g = S_CREATE(gctx); \ |
282 | g->c.ops = &gops; \ |
283 | pre##_counterinit(&g->k, k, sz, 0); \ |
284 | return (&g->c); \ |
285 | } \ |
286 | \ |
287 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ |
288 | { \ |
289 | gctx *g = (gctx *)c; \ |
290 | pre##_counterencrypt(&g->k, s, t, sz); \ |
291 | } \ |
292 | \ |
293 | static void gdestroy(gcipher *c) \ |
294 | { \ |
295 | gctx *g = (gctx *)c; \ |
296 | BURN(*g); \ |
297 | S_DESTROY(g); \ |
298 | } \ |
299 | \ |
300 | static void gsetiv(gcipher *c, const void *iv) \ |
301 | { \ |
302 | gctx *g = (gctx *)c; \ |
303 | pre##_countersetiv(&g->k, iv); \ |
304 | } \ |
305 | \ |
306 | static void gbdry(gcipher *c) \ |
307 | { \ |
308 | gctx *g = (gctx *)c; \ |
309 | pre##_counterbdry(&g->k); \ |
310 | } \ |
311 | \ |
312 | static const gcipher_ops gops = { \ |
313 | &pre##_counter, \ |
314 | gencrypt, gencrypt, gdestroy, gsetiv, gbdry \ |
315 | }; \ |
316 | \ |
317 | const gccipher pre##_counter = { \ |
318 | #pre "-counter", pre##_keysz, PRE##_BLKSZ, \ |
319 | ginit \ |
320 | }; \ |
321 | \ |
322 | /* --- Generic random number generator interface --- */ \ |
323 | \ |
324 | typedef struct grctx { \ |
325 | grand r; \ |
326 | pre##_counterctx k; \ |
327 | } grctx; \ |
328 | \ |
329 | static void grdestroy(grand *r) \ |
330 | { \ |
331 | grctx *g = (grctx *)r; \ |
332 | BURN(*g); \ |
333 | S_DESTROY(g); \ |
334 | } \ |
335 | \ |
336 | static int grmisc(grand *r, unsigned op, ...) \ |
337 | { \ |
338 | grctx *g = (grctx *)r; \ |
339 | va_list ap; \ |
340 | int rc = 0; \ |
341 | octet buf[PRE##_BLKSZ]; \ |
342 | va_start(ap, op); \ |
343 | \ |
344 | switch (op) { \ |
345 | case GRAND_CHECK: \ |
346 | switch (va_arg(ap, unsigned)) { \ |
347 | case GRAND_CHECK: \ |
348 | case GRAND_SEEDINT: \ |
349 | case GRAND_SEEDUINT32: \ |
350 | case GRAND_SEEDBLOCK: \ |
351 | case GRAND_SEEDRAND: \ |
352 | rc = 1; \ |
353 | break; \ |
354 | default: \ |
355 | rc = 0; \ |
356 | break; \ |
357 | } \ |
358 | break; \ |
359 | case GRAND_SEEDINT: \ |
360 | BLKC_SET(PRE, g->k.n, va_arg(ap, unsigned)); \ |
361 | g->k.off = PRE##_BLKSZ; \ |
362 | break; \ |
363 | case GRAND_SEEDUINT32: \ |
364 | BLKC_SET(PRE, g->k.n, va_arg(ap, uint32)); \ |
365 | g->k.off = PRE##_BLKSZ; \ |
366 | break; \ |
367 | case GRAND_SEEDBLOCK: { \ |
368 | const void *p = va_arg(ap, const void *); \ |
369 | size_t sz = va_arg(ap, size_t); \ |
370 | if (sz < sizeof(buf)) { \ |
371 | memset(buf, 0, sizeof(buf)); \ |
372 | memcpy(buf, p, sz); \ |
373 | p = buf; \ |
374 | } \ |
375 | pre##_countersetiv(&g->k, p); \ |
376 | } break; \ |
377 | case GRAND_SEEDRAND: { \ |
378 | grand *rr = va_arg(ap, grand *); \ |
379 | rr->ops->fill(rr, buf, sizeof(buf)); \ |
380 | pre##_countersetiv(&g->k, buf); \ |
381 | } break; \ |
382 | default: \ |
383 | GRAND_BADOP; \ |
384 | break; \ |
385 | } \ |
386 | \ |
387 | va_end(ap); \ |
388 | return (rc); \ |
389 | } \ |
390 | \ |
391 | static octet grbyte(grand *r) \ |
392 | { \ |
393 | grctx *g = (grctx *)r; \ |
394 | octet o; \ |
395 | pre##_counterencrypt(&g->k, 0, &o, 1); \ |
396 | return (o); \ |
397 | } \ |
398 | \ |
399 | static uint32 grword(grand *r) \ |
400 | { \ |
401 | grctx *g = (grctx *)r; \ |
402 | octet b[4]; \ |
403 | pre##_counterencrypt(&g->k, 0, b, sizeof(b)); \ |
404 | return (LOAD32(b)); \ |
405 | } \ |
406 | \ |
407 | static void grfill(grand *r, void *p, size_t sz) \ |
408 | { \ |
409 | grctx *g = (grctx *)r; \ |
410 | pre##_counterencrypt(&g->k, 0, p, sz); \ |
411 | } \ |
412 | \ |
413 | static const grand_ops grops = { \ |
414 | #pre "-counter", \ |
415 | GRAND_CRYPTO, 0, \ |
416 | grmisc, grdestroy, \ |
417 | grword, grbyte, grword, grand_range, grfill \ |
418 | }; \ |
419 | \ |
420 | /* --- @pre_counterrand@ --- * \ |
421 | * \ |
422 | * Arguments: @const void *k@ = pointer to key material \ |
423 | * @size_t sz@ = size of key material \ |
424 | * \ |
425 | * Returns: Pointer to generic random number generator interface. \ |
426 | * \ |
427 | * Use: Creates a random number interface wrapper around an \ |
428 | * counter-mode block cipher. \ |
429 | */ \ |
430 | \ |
431 | grand *pre##_counterrand(const void *k, size_t sz) \ |
432 | { \ |
433 | grctx *g = S_CREATE(grctx); \ |
434 | g->r.ops = &grops; \ |
435 | pre##_counterinit(&g->k, k, sz, 0); \ |
436 | return (&g->r); \ |
437 | } \ |
438 | \ |
439 | COUNTER_TEST(PRE, pre) |
440 | |
441 | /*----- Test rig ----------------------------------------------------------*/ |
442 | |
443 | #ifdef TEST_RIG |
444 | |
445 | #include <stdio.h> |
446 | |
447 | #include "daftstory.h" |
448 | |
449 | /* --- @COUNTER_TEST@ --- * |
450 | * |
451 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions |
452 | * |
453 | * Use: Standard test rig for counter functions. |
454 | */ |
455 | |
456 | #define COUNTER_TEST(PRE, pre) \ |
457 | \ |
458 | /* --- Initial plaintext for the test --- */ \ |
459 | \ |
460 | static const octet text[] = TEXT; \ |
461 | \ |
462 | /* --- Key and IV to use --- */ \ |
463 | \ |
464 | static const octet key[] = KEY; \ |
465 | static const octet iv[] = IV; \ |
466 | \ |
467 | /* --- Buffers for encryption and decryption output --- */ \ |
468 | \ |
469 | static octet ct[sizeof(text)]; \ |
470 | static octet pt[sizeof(text)]; \ |
471 | \ |
472 | static void hexdump(const octet *p, size_t sz) \ |
473 | { \ |
474 | const octet *q = p + sz; \ |
475 | for (sz = 0; p < q; p++, sz++) { \ |
476 | printf("%02x", *p); \ |
477 | if ((sz + 1) % PRE##_BLKSZ == 0) \ |
478 | putchar(':'); \ |
479 | } \ |
480 | } \ |
481 | \ |
482 | int main(void) \ |
483 | { \ |
484 | size_t sz = 0, rest; \ |
485 | pre##_counterctx ctx; \ |
486 | int status = 0; \ |
487 | int done = 0; \ |
488 | pre##_ctx k; \ |
489 | \ |
490 | size_t keysz = PRE##_KEYSZ ? \ |
491 | PRE##_KEYSZ : strlen((const char *)key); \ |
492 | \ |
493 | fputs(#pre "-counter: ", stdout); \ |
494 | \ |
495 | pre##_init(&k, key, keysz); \ |
496 | pre##_countersetkey(&ctx, &k); \ |
497 | \ |
498 | while (sz <= sizeof(text)) { \ |
499 | rest = sizeof(text) - sz; \ |
500 | memcpy(ct, text, sizeof(text)); \ |
501 | pre##_countersetiv(&ctx, iv); \ |
502 | pre##_counterencrypt(&ctx, ct, ct, sz); \ |
503 | pre##_counterencrypt(&ctx, ct + sz, ct + sz, rest); \ |
504 | memcpy(pt, ct, sizeof(text)); \ |
505 | pre##_countersetiv(&ctx, iv); \ |
506 | pre##_counterencrypt(&ctx, pt, pt, rest); \ |
507 | pre##_counterencrypt(&ctx, pt + rest, pt + rest, sz); \ |
508 | if (memcmp(pt, text, sizeof(text)) == 0) { \ |
509 | done++; \ |
510 | if (sizeof(text) < 40 || done % 8 == 0) \ |
511 | fputc('.', stdout); \ |
512 | if (done % 480 == 0) \ |
513 | fputs("\n\t", stdout); \ |
514 | fflush(stdout); \ |
515 | } else { \ |
516 | printf("\nError (sz = %lu)\n", (unsigned long)sz); \ |
517 | status = 1; \ |
518 | printf("\tplaintext = "); hexdump(text, sz); \ |
519 | printf(", "); hexdump(text + sz, rest); \ |
520 | fputc('\n', stdout); \ |
521 | printf("\tciphertext = "); hexdump(ct, sz); \ |
522 | printf(", "); hexdump(ct + sz, rest); \ |
523 | fputc('\n', stdout); \ |
524 | printf("\trecovered text = "); hexdump(pt, sz); \ |
525 | printf(", "); hexdump(pt + sz, rest); \ |
526 | fputc('\n', stdout); \ |
527 | fputc('\n', stdout); \ |
528 | } \ |
529 | if (sz < 63) \ |
530 | sz++; \ |
531 | else \ |
532 | sz += 9; \ |
533 | } \ |
534 | \ |
535 | fputs(status ? " failed\n" : " ok\n", stdout); \ |
536 | return (status); \ |
537 | } |
538 | |
539 | #else |
540 | # define COUNTER_TEST(PRE, pre) |
541 | #endif |
542 | |
543 | /*----- That's all, folks -------------------------------------------------*/ |
544 | |
545 | #ifdef __cplusplus |
546 | } |
547 | #endif |
548 | |
549 | #endif |