Commit | Line | Data |
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35d66180 | 1 | /* -*-c-*- |
35d66180 | 2 | * |
3 | * Block cipher counter mode (or long cycle mode) | |
4 | * | |
5 | * (c) 2000 Straylight/Edgeware | |
6 | */ | |
7 | ||
45c0fd36 | 8 | /*----- Licensing notice --------------------------------------------------* |
35d66180 | 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. | |
45c0fd36 | 16 | * |
35d66180 | 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. | |
45c0fd36 | 21 | * |
35d66180 | 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 | ||
35d66180 | 28 | #ifndef CATACOMB_COUNTER_DEF_H |
29 | #define CATACOMB_COUNTER_DEF_H | |
30 | ||
31 | #ifdef __cplusplus | |
32 | extern "C" { | |
33 | #endif | |
34 | ||
35 | /*----- Header files ------------------------------------------------------*/ | |
36 | ||
37 | #include <stdarg.h> | |
38 | #include <string.h> | |
39 | ||
40 | #include <mLib/bits.h> | |
41 | #include <mLib/sub.h> | |
42 | ||
43 | #ifndef CATACOMB_ARENA_H | |
44 | # include "arena.h" | |
45 | #endif | |
46 | ||
47 | #ifndef CATACOMB_BLKC_H | |
48 | # include "blkc.h" | |
49 | #endif | |
50 | ||
51 | #ifndef CATACOMB_GCIPHER_H | |
52 | # include "gcipher.h" | |
53 | #endif | |
54 | ||
55 | #ifndef CATACOMB_PARANOIA_H | |
56 | # include "paranoia.h" | |
57 | #endif | |
58 | ||
59 | /*----- Macros ------------------------------------------------------------*/ | |
60 | ||
61 | /* --- @COUNTER_DEF@ --- * | |
62 | * | |
63 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher | |
64 | * | |
65 | * Use: Creates definitions for counter mode. | |
66 | */ | |
67 | ||
68 | #define COUNTER_DEF(PRE, pre) \ | |
69 | \ | |
70 | /* --- @pre_countergetiv@ --- * \ | |
71 | * \ | |
72 | * Arguments: @const pre_counterctx *ctx@ = pointer to counter \ | |
73 | * context \ | |
4efe32ba | 74 | * @void *iv@ = pointer to output data block \ |
35d66180 | 75 | * \ |
76 | * Returns: --- \ | |
77 | * \ | |
78 | * Use: Reads the currently set IV. Reading and setting an IV \ | |
79 | * is not transparent to the cipher. It will add a `step' \ | |
80 | * which must be matched by a similar operation during \ | |
81 | * decryption. \ | |
82 | */ \ | |
83 | \ | |
84 | void pre##_countergetiv(const pre##_counterctx *ctx, void *iv) \ | |
85 | { \ | |
86 | BLKC_STORE(PRE, iv, ctx->n); \ | |
87 | } \ | |
88 | \ | |
89 | /* --- @pre_countersetiv@ --- * \ | |
90 | * \ | |
91 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
92 | * @cnost void *iv@ = pointer to IV to set \ | |
93 | * \ | |
94 | * Returns: --- \ | |
95 | * \ | |
96 | * Use: Sets the IV to use for subsequent encryption. \ | |
97 | */ \ | |
98 | \ | |
99 | void pre##_countersetiv(pre##_counterctx *ctx, const void *iv) \ | |
100 | { \ | |
101 | BLKC_LOAD(PRE, ctx->n, iv); \ | |
102 | ctx->off = PRE##_BLKSZ; \ | |
103 | } \ | |
104 | \ | |
105 | /* --- @pre_counterbdry@ --- * \ | |
106 | * \ | |
107 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
108 | * \ | |
109 | * Returns: --- \ | |
110 | * \ | |
111 | * Use: Inserts a boundary during encryption. Successful \ | |
112 | * decryption must place a similar boundary. \ | |
113 | */ \ | |
114 | \ | |
115 | void pre##_counterbdry(pre##_counterctx *ctx) \ | |
116 | { \ | |
117 | BLKC_STEP(PRE, ctx->n); \ | |
118 | ctx->off = PRE##_BLKSZ; \ | |
119 | } \ | |
120 | \ | |
121 | /* --- @pre_countersetkey@ --- * \ | |
122 | * \ | |
123 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
124 | * @const pre_ctx *k@ = pointer to cipher context \ | |
125 | * \ | |
126 | * Returns: --- \ | |
127 | * \ | |
128 | * Use: Sets the counter context to use a different cipher key. \ | |
129 | */ \ | |
130 | \ | |
131 | void pre##_countersetkey(pre##_counterctx *ctx, const pre##_ctx *k) \ | |
132 | { \ | |
133 | ctx->ctx = *k; \ | |
134 | } \ | |
135 | \ | |
136 | /* --- @pre_counterinit@ --- * \ | |
137 | * \ | |
138 | * Arguments: @pre_counterctx *ctx@ = pointer to cipher context \ | |
139 | * @const void *key@ = pointer to the key buffer \ | |
140 | * @size_t sz@ = size of the key \ | |
141 | * @const void *iv@ = pointer to initialization vector \ | |
142 | * \ | |
143 | * Returns: --- \ | |
144 | * \ | |
145 | * Use: Initializes a counter context ready for use. You \ | |
146 | * should ensure that the IV chosen is unique: reusing an \ | |
147 | * IV will compromise the security of the entire \ | |
148 | * plaintext. This is equivalent to calls to @pre_init@, \ | |
149 | * @pre_countersetkey@ and @pre_countersetiv@. \ | |
150 | */ \ | |
151 | \ | |
152 | void pre##_counterinit(pre##_counterctx *ctx, \ | |
153 | const void *key, size_t sz, \ | |
154 | const void *iv) \ | |
155 | { \ | |
4e66da02 | 156 | static const octet zero[PRE##_BLKSZ] = { 0 }; \ |
35d66180 | 157 | pre##_init(&ctx->ctx, key, sz); \ |
158 | pre##_countersetiv(ctx, iv ? iv : zero); \ | |
159 | } \ | |
160 | \ | |
161 | /* --- @pre_counterencrypt@ --- * \ | |
162 | * \ | |
163 | * Arguments: @pre_counterctx *ctx@ = pointer to counter context \ | |
164 | * @const void *src@ = pointer to source data \ | |
165 | * @void *dest@ = pointer to destination data \ | |
166 | * @size_t sz@ = size of block to be encrypted \ | |
167 | * \ | |
168 | * Returns: --- \ | |
169 | * \ | |
170 | * Use: Encrypts or decrypts a block with a block cipher in \ | |
171 | * counter mode: encryption and decryption are the same in \ | |
172 | * counter. The destination may be null to just churn the \ | |
173 | * feedback round for a bit. The source may be null to \ | |
174 | * use the cipher as a random data generator. \ | |
175 | */ \ | |
176 | \ | |
177 | void pre##_counterencrypt(pre##_counterctx *ctx, \ | |
178 | const void *src, void *dest, \ | |
179 | size_t sz) \ | |
180 | { \ | |
181 | const octet *s = src; \ | |
182 | octet *d = dest; \ | |
183 | unsigned off = ctx->off; \ | |
184 | \ | |
185 | /* --- Empty blocks are trivial --- */ \ | |
186 | \ | |
187 | if (!sz) \ | |
188 | return; \ | |
189 | \ | |
190 | /* --- If I can deal with the block from my buffer, do that --- */ \ | |
191 | \ | |
192 | if (sz < PRE##_BLKSZ - off) \ | |
193 | goto small; \ | |
194 | \ | |
195 | /* --- Finish off what's left in my buffer --- */ \ | |
196 | \ | |
197 | if (!d) \ | |
198 | sz -= PRE##_BLKSZ - off; \ | |
199 | else { \ | |
200 | while (off < PRE##_BLKSZ) { \ | |
201 | register octet x = s ? *s++ : 0; \ | |
202 | *d++ = ctx->buf[off++] ^ x; \ | |
203 | sz--; \ | |
204 | } \ | |
205 | } \ | |
206 | \ | |
207 | /* --- Main encryption loop --- */ \ | |
208 | \ | |
209 | { \ | |
210 | uint32 n[PRE##_BLKSZ / 4]; \ | |
211 | \ | |
45c0fd36 | 212 | for (;;) { \ |
35d66180 | 213 | pre##_eblk(&ctx->ctx, ctx->n, n); \ |
214 | BLKC_STEP(PRE, ctx->n); \ | |
215 | if (sz < PRE##_BLKSZ) \ | |
216 | break; \ | |
217 | if (d) { \ | |
218 | if (!s) \ | |
219 | BLKC_STORE(PRE, d, n); \ | |
220 | else { \ | |
221 | uint32 x[PRE##_BLKSZ / 4]; \ | |
222 | BLKC_LOAD(PRE, x, s); \ | |
223 | BLKC_XSTORE(PRE, d, n, x); \ | |
224 | s += PRE##_BLKSZ; \ | |
225 | } \ | |
226 | d += PRE##_BLKSZ; \ | |
227 | } \ | |
228 | sz -= PRE##_BLKSZ; \ | |
229 | } \ | |
230 | \ | |
231 | BLKC_STORE(PRE, ctx->buf, n); \ | |
232 | off = 0; \ | |
233 | } \ | |
234 | \ | |
235 | /* --- Tidying up the tail end --- */ \ | |
236 | \ | |
237 | if (sz) { \ | |
238 | small: \ | |
239 | if (!d) \ | |
240 | off += sz; \ | |
241 | else do { \ | |
242 | register octet x = s ? *s++ : 0; \ | |
243 | *d++ = ctx->buf[off++] ^ x; \ | |
244 | sz--; \ | |
245 | } while (sz); \ | |
246 | } \ | |
247 | \ | |
248 | /* --- Done --- */ \ | |
249 | \ | |
250 | ctx->off = off; \ | |
251 | return; \ | |
252 | } \ | |
253 | \ | |
254 | /* --- Generic cipher interface --- */ \ | |
255 | \ | |
256 | static const gcipher_ops gops; \ | |
257 | \ | |
258 | typedef struct gctx { \ | |
259 | gcipher c; \ | |
260 | pre##_counterctx k; \ | |
261 | } gctx; \ | |
262 | \ | |
263 | static gcipher *ginit(const void *k, size_t sz) \ | |
264 | { \ | |
265 | gctx *g = S_CREATE(gctx); \ | |
266 | g->c.ops = &gops; \ | |
267 | pre##_counterinit(&g->k, k, sz, 0); \ | |
268 | return (&g->c); \ | |
269 | } \ | |
270 | \ | |
271 | static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \ | |
272 | { \ | |
273 | gctx *g = (gctx *)c; \ | |
274 | pre##_counterencrypt(&g->k, s, t, sz); \ | |
275 | } \ | |
276 | \ | |
277 | static void gdestroy(gcipher *c) \ | |
278 | { \ | |
279 | gctx *g = (gctx *)c; \ | |
280 | BURN(*g); \ | |
281 | S_DESTROY(g); \ | |
282 | } \ | |
283 | \ | |
284 | static void gsetiv(gcipher *c, const void *iv) \ | |
285 | { \ | |
286 | gctx *g = (gctx *)c; \ | |
287 | pre##_countersetiv(&g->k, iv); \ | |
288 | } \ | |
289 | \ | |
290 | static void gbdry(gcipher *c) \ | |
291 | { \ | |
292 | gctx *g = (gctx *)c; \ | |
293 | pre##_counterbdry(&g->k); \ | |
294 | } \ | |
295 | \ | |
296 | static const gcipher_ops gops = { \ | |
297 | &pre##_counter, \ | |
298 | gencrypt, gencrypt, gdestroy, gsetiv, gbdry \ | |
299 | }; \ | |
300 | \ | |
301 | const gccipher pre##_counter = { \ | |
302 | #pre "-counter", pre##_keysz, PRE##_BLKSZ, \ | |
303 | ginit \ | |
304 | }; \ | |
305 | \ | |
306 | /* --- Generic random number generator interface --- */ \ | |
307 | \ | |
308 | typedef struct grctx { \ | |
309 | grand r; \ | |
310 | pre##_counterctx k; \ | |
311 | } grctx; \ | |
312 | \ | |
313 | static void grdestroy(grand *r) \ | |
314 | { \ | |
315 | grctx *g = (grctx *)r; \ | |
316 | BURN(*g); \ | |
317 | S_DESTROY(g); \ | |
318 | } \ | |
319 | \ | |
320 | static int grmisc(grand *r, unsigned op, ...) \ | |
321 | { \ | |
322 | grctx *g = (grctx *)r; \ | |
323 | va_list ap; \ | |
324 | int rc = 0; \ | |
325 | octet buf[PRE##_BLKSZ]; \ | |
326 | va_start(ap, op); \ | |
327 | \ | |
328 | switch (op) { \ | |
329 | case GRAND_CHECK: \ | |
330 | switch (va_arg(ap, unsigned)) { \ | |
331 | case GRAND_CHECK: \ | |
332 | case GRAND_SEEDINT: \ | |
333 | case GRAND_SEEDUINT32: \ | |
334 | case GRAND_SEEDBLOCK: \ | |
335 | case GRAND_SEEDRAND: \ | |
336 | rc = 1; \ | |
337 | break; \ | |
338 | default: \ | |
339 | rc = 0; \ | |
340 | break; \ | |
341 | } \ | |
342 | break; \ | |
343 | case GRAND_SEEDINT: \ | |
344 | BLKC_SET(PRE, g->k.n, va_arg(ap, unsigned)); \ | |
345 | g->k.off = PRE##_BLKSZ; \ | |
346 | break; \ | |
347 | case GRAND_SEEDUINT32: \ | |
348 | BLKC_SET(PRE, g->k.n, va_arg(ap, uint32)); \ | |
349 | g->k.off = PRE##_BLKSZ; \ | |
350 | break; \ | |
351 | case GRAND_SEEDBLOCK: { \ | |
352 | const void *p = va_arg(ap, const void *); \ | |
353 | size_t sz = va_arg(ap, size_t); \ | |
354 | if (sz < sizeof(buf)) { \ | |
355 | memset(buf, 0, sizeof(buf)); \ | |
356 | memcpy(buf, p, sz); \ | |
357 | p = buf; \ | |
358 | } \ | |
359 | pre##_countersetiv(&g->k, p); \ | |
360 | } break; \ | |
361 | case GRAND_SEEDRAND: { \ | |
362 | grand *rr = va_arg(ap, grand *); \ | |
363 | rr->ops->fill(rr, buf, sizeof(buf)); \ | |
364 | pre##_countersetiv(&g->k, buf); \ | |
365 | } break; \ | |
366 | default: \ | |
367 | GRAND_BADOP; \ | |
368 | break; \ | |
369 | } \ | |
370 | \ | |
371 | va_end(ap); \ | |
372 | return (rc); \ | |
373 | } \ | |
374 | \ | |
375 | static octet grbyte(grand *r) \ | |
376 | { \ | |
377 | grctx *g = (grctx *)r; \ | |
378 | octet o; \ | |
379 | pre##_counterencrypt(&g->k, 0, &o, 1); \ | |
380 | return (o); \ | |
381 | } \ | |
382 | \ | |
383 | static uint32 grword(grand *r) \ | |
384 | { \ | |
385 | grctx *g = (grctx *)r; \ | |
386 | octet b[4]; \ | |
387 | pre##_counterencrypt(&g->k, 0, b, sizeof(b)); \ | |
388 | return (LOAD32(b)); \ | |
389 | } \ | |
390 | \ | |
391 | static void grfill(grand *r, void *p, size_t sz) \ | |
392 | { \ | |
393 | grctx *g = (grctx *)r; \ | |
394 | pre##_counterencrypt(&g->k, 0, p, sz); \ | |
395 | } \ | |
396 | \ | |
397 | static const grand_ops grops = { \ | |
398 | #pre "-counter", \ | |
399 | GRAND_CRYPTO, 0, \ | |
400 | grmisc, grdestroy, \ | |
44ff6c11 | 401 | grword, grbyte, grword, grand_defaultrange, grfill \ |
35d66180 | 402 | }; \ |
403 | \ | |
404 | /* --- @pre_counterrand@ --- * \ | |
405 | * \ | |
406 | * Arguments: @const void *k@ = pointer to key material \ | |
407 | * @size_t sz@ = size of key material \ | |
408 | * \ | |
409 | * Returns: Pointer to generic random number generator interface. \ | |
410 | * \ | |
411 | * Use: Creates a random number interface wrapper around an \ | |
412 | * counter-mode block cipher. \ | |
413 | */ \ | |
414 | \ | |
415 | grand *pre##_counterrand(const void *k, size_t sz) \ | |
416 | { \ | |
417 | grctx *g = S_CREATE(grctx); \ | |
418 | g->r.ops = &grops; \ | |
419 | pre##_counterinit(&g->k, k, sz, 0); \ | |
420 | return (&g->r); \ | |
421 | } \ | |
422 | \ | |
423 | COUNTER_TEST(PRE, pre) | |
424 | ||
425 | /*----- Test rig ----------------------------------------------------------*/ | |
426 | ||
427 | #ifdef TEST_RIG | |
428 | ||
429 | #include <stdio.h> | |
430 | ||
431 | #include "daftstory.h" | |
432 | ||
433 | /* --- @COUNTER_TEST@ --- * | |
434 | * | |
435 | * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions | |
436 | * | |
437 | * Use: Standard test rig for counter functions. | |
438 | */ | |
439 | ||
440 | #define COUNTER_TEST(PRE, pre) \ | |
441 | \ | |
442 | /* --- Initial plaintext for the test --- */ \ | |
443 | \ | |
444 | static const octet text[] = TEXT; \ | |
445 | \ | |
446 | /* --- Key and IV to use --- */ \ | |
447 | \ | |
448 | static const octet key[] = KEY; \ | |
449 | static const octet iv[] = IV; \ | |
450 | \ | |
451 | /* --- Buffers for encryption and decryption output --- */ \ | |
452 | \ | |
453 | static octet ct[sizeof(text)]; \ | |
454 | static octet pt[sizeof(text)]; \ | |
455 | \ | |
12331b2d | 456 | static void hexdump(const octet *p, size_t sz, size_t off) \ |
35d66180 | 457 | { \ |
458 | const octet *q = p + sz; \ | |
459 | for (sz = 0; p < q; p++, sz++) { \ | |
460 | printf("%02x", *p); \ | |
12331b2d | 461 | if ((off + sz + 1) % PRE##_BLKSZ == 0) \ |
35d66180 | 462 | putchar(':'); \ |
463 | } \ | |
464 | } \ | |
465 | \ | |
466 | int main(void) \ | |
467 | { \ | |
468 | size_t sz = 0, rest; \ | |
469 | pre##_counterctx ctx; \ | |
470 | int status = 0; \ | |
471 | int done = 0; \ | |
472 | pre##_ctx k; \ | |
473 | \ | |
474 | size_t keysz = PRE##_KEYSZ ? \ | |
475 | PRE##_KEYSZ : strlen((const char *)key); \ | |
476 | \ | |
477 | fputs(#pre "-counter: ", stdout); \ | |
478 | \ | |
479 | pre##_init(&k, key, keysz); \ | |
480 | pre##_countersetkey(&ctx, &k); \ | |
481 | \ | |
482 | while (sz <= sizeof(text)) { \ | |
483 | rest = sizeof(text) - sz; \ | |
484 | memcpy(ct, text, sizeof(text)); \ | |
485 | pre##_countersetiv(&ctx, iv); \ | |
486 | pre##_counterencrypt(&ctx, ct, ct, sz); \ | |
487 | pre##_counterencrypt(&ctx, ct + sz, ct + sz, rest); \ | |
488 | memcpy(pt, ct, sizeof(text)); \ | |
489 | pre##_countersetiv(&ctx, iv); \ | |
490 | pre##_counterencrypt(&ctx, pt, pt, rest); \ | |
491 | pre##_counterencrypt(&ctx, pt + rest, pt + rest, sz); \ | |
492 | if (memcmp(pt, text, sizeof(text)) == 0) { \ | |
493 | done++; \ | |
494 | if (sizeof(text) < 40 || done % 8 == 0) \ | |
45c0fd36 | 495 | fputc('.', stdout); \ |
35d66180 | 496 | if (done % 480 == 0) \ |
45c0fd36 | 497 | fputs("\n\t", stdout); \ |
35d66180 | 498 | fflush(stdout); \ |
499 | } else { \ | |
500 | printf("\nError (sz = %lu)\n", (unsigned long)sz); \ | |
501 | status = 1; \ | |
12331b2d MW |
502 | printf("\tplaintext = "); hexdump(text, sz, 0); \ |
503 | printf(", "); hexdump(text + sz, rest, sz); \ | |
45c0fd36 | 504 | fputc('\n', stdout); \ |
12331b2d MW |
505 | printf("\tciphertext = "); hexdump(ct, sz, 0); \ |
506 | printf(", "); hexdump(ct + sz, rest, sz); \ | |
45c0fd36 | 507 | fputc('\n', stdout); \ |
12331b2d MW |
508 | printf("\trecovered text = "); hexdump(pt, sz, 0); \ |
509 | printf(", "); hexdump(pt + sz, rest, sz); \ | |
45c0fd36 | 510 | fputc('\n', stdout); \ |
35d66180 | 511 | fputc('\n', stdout); \ |
512 | } \ | |
513 | if (sz < 63) \ | |
514 | sz++; \ | |
515 | else \ | |
516 | sz += 9; \ | |
517 | } \ | |
518 | \ | |
519 | fputs(status ? " failed\n" : " ok\n", stdout); \ | |
520 | return (status); \ | |
521 | } | |
522 | ||
523 | #else | |
524 | # define COUNTER_TEST(PRE, pre) | |
525 | #endif | |
526 | ||
527 | /*----- That's all, folks -------------------------------------------------*/ | |
528 | ||
529 | #ifdef __cplusplus | |
530 | } | |
531 | #endif | |
532 | ||
533 | #endif |