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