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1 | /* -*-c-*- |
2 | * | |
3 | * The CCM authenticated-encryption mode | |
4 | * | |
5 | * (c) 2017 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_CCM_DEF_H | |
29 | #define CATACOMB_CCM_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_CT_H | |
51 | # include "ct.h" | |
52 | #endif | |
53 | ||
54 | #ifndef CATACOMB_KEYSZ_H | |
55 | # include "keysz.h" | |
56 | #endif | |
57 | ||
58 | #ifndef CATACOMB_PARANOIA_H | |
59 | # include "paranoia.h" | |
60 | #endif | |
61 | ||
62 | #ifndef CATACOMB_RSVR_H | |
63 | # include "rsvr.h" | |
64 | #endif | |
65 | ||
66 | /*----- Common machinery --------------------------------------------------*/ | |
67 | ||
68 | /* --- @ccm_check@ --- * | |
69 | * | |
70 | * Arguments: @const ccm_params *p@ = pointer to parameters | |
71 | * | |
72 | * Returns: True (nonzero) if the parameters are OK; false (zero) if | |
73 | * there's a problem. | |
74 | * | |
75 | * Use: Verify that the CCM parameters are acceptable. | |
76 | */ | |
77 | ||
78 | extern int ccm_check(const ccm_params */*p*/); | |
79 | ||
80 | /* --- @ccm_fmthdr@ --- * | |
81 | * | |
82 | * Arguments: @const ccm_params *p@ = pointer to parameters | |
83 | * @octet *b@ = block-size buffer to write header | |
84 | * @const void *n@ = pointer to nonce | |
85 | * | |
86 | * Returns: --- | |
87 | * | |
88 | * Use: Format a MAC header block. | |
89 | */ | |
90 | ||
91 | extern void ccm_fmthdr(const ccm_params */*p*/, | |
92 | octet */*b*/, const void */*n*/); | |
93 | ||
94 | /* --- @ccm_fmtctr@ --- * | |
95 | * | |
96 | * Arguments: @const ccm_params *p@ = pointer to parameters | |
97 | * @octet *b@ = block-size buffer to write header | |
98 | * @const void *n@ = pointer to nonce | |
99 | * | |
100 | * Returns: --- | |
101 | * | |
102 | * Use: Format an initial counter block. | |
103 | */ | |
104 | ||
105 | extern void ccm_fmtctr(const ccm_params */*p*/, | |
106 | octet */*b*/, const void */*n*/); | |
107 | ||
108 | /*----- Macros ------------------------------------------------------------*/ | |
109 | ||
110 | /* --- @CCM_DEF@ --- * | |
111 | * | |
112 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher | |
113 | * | |
114 | * Use: Creates an implementation for the CCM authenticated- | |
115 | * encryption mode. | |
116 | */ | |
117 | ||
118 | #define CCM_DEF(PRE, pre) CCM_DEFX(PRE, pre, #pre, #pre) | |
119 | ||
120 | #define CCM_DEFX(PRE, pre, name, fname) \ | |
121 | \ | |
122 | const octet pre##_ccmnoncesz[] = \ | |
123 | { KSZ_RANGE, PRE##_BLKSZ/2 - (PRE##_BLKSZ <= 16 ? 1 : 2), \ | |
124 | CCM_NSZMIN(PRE), CCM_NSZMAX(PRE), 1 }; \ | |
125 | const octet pre##_ccmtagsz[] = \ | |
126 | { KSZ_RANGE, CCM_TSZMAX(PRE), \ | |
127 | CCM_TSZMIN(PRE), CCM_TSZMAX(PRE), PRE##_BLKSZ == 16 ? 2 : 1 }; \ | |
128 | \ | |
129 | static const rsvr_policy pre##_ccmpolicy = \ | |
130 | { RSVRF_FULL, PRE##_BLKSZ, PRE##_BLKSZ }; \ | |
131 | \ | |
132 | /* --- @pre_ccminthash@ --- * \ | |
133 | * \ | |
134 | * Arguments: @pre_ccmctx *ctx@ = pointer to context block \ | |
135 | * @const void *p@ = pointer to material to hash \ | |
136 | * @size_t sz@ = size of the input buffer \ | |
137 | * \ | |
138 | * Returns: --- \ | |
139 | * \ | |
140 | * Use: Internal operation for feeding stuff into the CBC-MAC \ | |
141 | * context. \ | |
142 | */ \ | |
143 | \ | |
144 | static void pre##_ccminthash(pre##_ccmctx *ctx, \ | |
145 | const void *p, size_t sz) \ | |
146 | { \ | |
147 | rsvr_state st; \ | |
148 | const octet *q; \ | |
149 | \ | |
150 | rsvr_setup(&st, &pre##_ccmpolicy, ctx->b, &ctx->off, p, sz); \ | |
151 | RSVR_DO(&st) while ((q = RSVR_NEXT(&st, PRE##_BLKSZ)) != 0) { \ | |
152 | BLKC_XLOAD(PRE, ctx->a, q); \ | |
153 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ | |
154 | } \ | |
155 | } \ | |
156 | \ | |
157 | /* --- @pre_ccminit@ --- * \ | |
158 | * \ | |
159 | * Arguments: @pre_ccmctx *aad@ = pointer to CCM context \ | |
160 | * @const pre_ctx *k@ = pointer to key material \ | |
161 | * @const void *n@ = pointer to nonce \ | |
162 | * @size_t nsz@ = size of the nonce \ | |
163 | * @size_t hsz@ = size of the AAD \ | |
164 | * @size_t msz@ = size of the message/ciphertext \ | |
165 | * @size_t tsz@ = size of the tag to produce \ | |
166 | * \ | |
167 | * Returns: Zero on success; nonzero if the parameters are invalid. \ | |
168 | * \ | |
169 | * Use: Initialize an CCM operation context with a given key. \ | |
170 | * \ | |
171 | * The original key needn't be kept around any more. \ | |
172 | */ \ | |
173 | \ | |
174 | int pre##_ccminit(pre##_ccmctx *ctx, const pre##_ctx *k, \ | |
175 | const void *n, size_t nsz, \ | |
176 | size_t hsz, size_t msz, size_t tsz) \ | |
177 | { ctx->k = *k; return (pre##_ccmreinit(ctx, n, nsz, hsz, msz, tsz)); } \ | |
178 | \ | |
179 | /* --- @pre_ccmreinit@ --- * \ | |
180 | * \ | |
181 | * Arguments: @pre_ccmctx *ctx@ = pointer to CCM context \ | |
182 | * @const void *n@ = pointer to nonce \ | |
183 | * @size_t nsz@ = size of nonce \ | |
184 | * @size_t hsz@ = size of the AAD \ | |
185 | * @size_t msz@ = size of the message/ciphertext \ | |
186 | * @size_t tsz@ = size of the tag to produce \ | |
187 | * \ | |
188 | * Returns: Zero on success; nonzero if the parameters are invalid. \ | |
189 | * \ | |
190 | * Use: Reinitialize an CCM operation context, changing the \ | |
191 | * nonce. \ | |
192 | */ \ | |
193 | \ | |
194 | int pre##_ccmreinit(pre##_ccmctx *ctx, const void *n, size_t nsz, \ | |
195 | size_t hsz, size_t msz, size_t tsz) \ | |
196 | { \ | |
197 | kludge64 t; \ | |
198 | octet b[12]; \ | |
199 | size_t sz; \ | |
200 | \ | |
201 | /* Set up the parameters and check that they make sense. */ \ | |
202 | ctx->p.hsz = hsz; ctx->p.msz = msz; \ | |
203 | ctx->p.bsz = PRE##_BLKSZ; ctx->p.nsz = nsz; ctx->p.tsz = tsz; \ | |
204 | if (!ccm_check(&ctx->p)) return (-1); \ | |
205 | \ | |
206 | /* Prepare the counter and the final MAC mask. The initial counter \ | |
207 | * is used to make the MAC mask, so generate that, keeping it for \ | |
208 | * later. \ | |
209 | */ \ | |
210 | ccm_fmtctr(&ctx->p, ctx->b, n); \ | |
211 | BLKC_LOAD(PRE, ctx->c, ctx->b); \ | |
212 | pre##_eblk(&ctx->k, ctx->c, ctx->s0); \ | |
213 | \ | |
214 | /* Prepare the MAC header and leave it in the buffer. */ \ | |
215 | ccm_fmthdr(&ctx->p, ctx->b, n); \ | |
216 | BLKC_ZERO(PRE, ctx->a); \ | |
217 | \ | |
218 | /* Initialize our state. The buffer is currently full (with the \ | |
219 | * MAC header), and we're always awaiting AAD, though we've not yet \ | |
220 | * seen any. (Even if we're not expecting AAD, this will trigger \ | |
221 | * appropriate initialization when encryption or decryption begins.) \ | |
222 | */ \ | |
223 | ctx->off = PRE##_BLKSZ; ctx->i = 0; \ | |
224 | ctx->st = CCMST_AAD; \ | |
225 | \ | |
226 | /* If there's AAD to come, then do the AAD framing. This aligns \ | |
227 | * badly with the blocking, so feed the framing in the hard way. \ | |
228 | */ \ | |
229 | if (hsz) { \ | |
230 | if (hsz < 0xfffe) \ | |
231 | { STORE16(b, hsz); sz = 2; } \ | |
232 | else if (hsz <= MASK32) \ | |
233 | { b[0] = 0xff; b[1] = 0xfe; STORE32(b + 2, hsz); sz = 6; } \ | |
234 | else { \ | |
235 | b[0] = b[1] = 0xff; \ | |
236 | ASSIGN64(t, hsz); STORE64_(b + 2, t); \ | |
237 | sz = 10; \ | |
238 | } \ | |
239 | pre##_ccminthash(ctx, b, sz); \ | |
240 | } \ | |
241 | \ | |
242 | /* All done. */ \ | |
243 | return (0); \ | |
244 | } \ | |
245 | \ | |
246 | /* --- @pre_ccmaadhash@ --- * \ | |
247 | * \ | |
248 | * Arguments: @pre_ccmctx *ctx@ = pointer to AAD context \ | |
249 | * @const void *p@ = pointer to AAD material \ | |
250 | * @size_t sz@ = length of AAD material \ | |
251 | * \ | |
252 | * Returns: --- \ | |
253 | * \ | |
254 | * Use: Feeds AAD into the context. This must be done before \ | |
255 | * any of the message/ciphertext is processed because CCM \ | |
256 | * is really annoying like that. \ | |
257 | */ \ | |
258 | \ | |
259 | void pre##_ccmaadhash(pre##_ccmctx *ctx, const void *p, size_t sz) \ | |
260 | { \ | |
261 | assert(ctx->st == CCMST_AAD); \ | |
262 | assert(sz <= ctx->p.hsz - ctx->i); \ | |
263 | ctx->i += sz; \ | |
264 | pre##_ccminthash(ctx, p, sz); \ | |
265 | } \ | |
266 | \ | |
267 | /* --- @pre_ccmencdecsetup@ --- * \ | |
268 | * \ | |
269 | * Arguments: @pre_ccmctx *ctx@ = pointer to context block \ | |
270 | * @size_t sz@ = size of message block \ | |
271 | * \ | |
272 | * Returns: --- \ | |
273 | * \ | |
274 | * Use: Prepares for an encrypt or decryption operation, \ | |
275 | * transitioning from the AAD state and updating the \ | |
276 | * message size. \ | |
277 | */ \ | |
278 | \ | |
279 | static void pre##_ccmencdecsetup(pre##_ccmctx *ctx, size_t sz) \ | |
280 | { \ | |
281 | if (ctx->st != CCMST_MSG) { \ | |
282 | /* Make sure we're currently in the AAD state and we've seen all of \ | |
283 | * the AAD we expected. \ | |
284 | */ \ | |
285 | assert(ctx->st == CCMST_AAD); \ | |
286 | assert(ctx->i == ctx->p.hsz); \ | |
287 | \ | |
288 | /* Pad the final AAD block out until we hit a block boundary. Note \ | |
289 | * that we don't cycle the block cipher here: instead, leave the \ | |
290 | * buffer full so that we do that next time. \ | |
291 | */ \ | |
292 | memset(ctx->b + ctx->off, 0, PRE##_BLKSZ - ctx->off); \ | |
293 | ctx->off = PRE##_BLKSZ; \ | |
294 | \ | |
295 | /* Now we're ready to process the message text. */ \ | |
296 | ctx->st = CCMST_MSG; ctx->i = 0; \ | |
297 | } \ | |
298 | \ | |
299 | /* Update the size. */ \ | |
300 | assert(sz <= ctx->p.msz - ctx->i); \ | |
301 | ctx->i += sz; \ | |
302 | } \ | |
303 | \ | |
304 | /* --- @pre_ccmencrypt@ --- * \ | |
305 | * \ | |
306 | * Arguments: @pre_ccmctx *ctx@ = pointer to CCM operation context \ | |
307 | * @const void *src@ = pointer to plaintext message chunk \ | |
308 | * @size_t sz@ = size of the plaintext \ | |
309 | * @buf *dst@ = a buffer to write the ciphertext to \ | |
310 | * \ | |
311 | * Returns: Zero on success; @-1@ on failure. \ | |
312 | * \ | |
313 | * Use: Encrypts a chunk of a plaintext message, writing a \ | |
314 | * chunk of ciphertext to the output buffer and updating \ | |
315 | * the operation state. \ | |
316 | * \ | |
317 | * For CCM, we always write a ciphertext chunk the same \ | |
318 | * size as the plaintext. The messing about with @buf@ \ | |
319 | * objects makes the interface consistent with other AEAD \ | |
320 | * schemes which can't do this. \ | |
321 | */ \ | |
322 | \ | |
323 | int pre##_ccmencrypt(pre##_ccmctx *ctx, \ | |
324 | const void *src, size_t sz, buf *dst) \ | |
325 | { \ | |
326 | rsvr_plan plan; \ | |
327 | uint32 t[PRE##_BLKSZ/4], u[PRE##_BLKSZ]; \ | |
328 | const octet *p = src; \ | |
329 | octet *q, *r, y; \ | |
330 | \ | |
331 | /* Allocate space for the ciphertext. */ \ | |
332 | if (sz) { q = buf_get(dst, sz); if (!q) return (-1); } \ | |
333 | else q = 0; \ | |
334 | \ | |
335 | /* Set stuff up. */ \ | |
336 | pre##_ccmencdecsetup(ctx, sz); \ | |
337 | \ | |
338 | /* Determine the buffering plan. Our buffer is going to do double- \ | |
339 | * duty here. The end portion is going to contain mask from the \ | |
340 | * encrypted counter which we mix into the plaintext to encrypt it; \ | |
341 | * the start portion, which originally mask bytes we've already used, \ | |
342 | * will hold the input plaintext, which will eventually be \ | |
343 | * collected into the CBC-MAC state. \ | |
344 | */ \ | |
345 | rsvr_mkplan(&plan, &pre##_ccmpolicy, ctx->off, sz); \ | |
346 | \ | |
347 | /* Initial portion, fulfilled from the buffer. If the buffer is \ | |
348 | * empty, then that means that we haven't yet encrypted the current \ | |
349 | * counter, so we should do that and advance it. \ | |
350 | */ \ | |
351 | if (plan.head) { \ | |
352 | if (!ctx->off) { \ | |
353 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ | |
354 | BLKC_STORE(PRE, ctx->b, t); \ | |
355 | } \ | |
356 | r = ctx->b + ctx->off; ctx->off += plan.head; \ | |
357 | while (plan.head--) { y = *p++; *q++ = y ^ *r; *r++ = y; } \ | |
358 | } \ | |
359 | \ | |
360 | /* If we've filled up the buffer then we need to cycle the MAC and \ | |
361 | * reset the offset. \ | |
362 | */ \ | |
363 | if (plan.from_rsvr) { \ | |
364 | BLKC_XLOAD(PRE, ctx->a, ctx->b); \ | |
365 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ | |
366 | ctx->off = 0; \ | |
367 | } \ | |
368 | \ | |
369 | /* Now to process the main body of the input. */ \ | |
370 | while (plan.from_input) { \ | |
371 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ | |
372 | BLKC_LOAD(PRE, u, p); p += PRE##_BLKSZ; \ | |
373 | BLKC_XSTORE(PRE, q, t, u); q += PRE##_BLKSZ; \ | |
374 | BLKC_XMOVE(PRE, ctx->a, u); pre##_eblk(&ctx->k, ctx->a, ctx->a); \ | |
375 | plan.from_input -= PRE##_BLKSZ; \ | |
376 | } \ | |
377 | \ | |
378 | /* Finally, deal with any final portion. If there is one, we know \ | |
379 | * that the buffer is empty: we must have filled it above, or this \ | |
380 | * would all count as `initial' data. \ | |
381 | */ \ | |
382 | if (plan.tail) { \ | |
383 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ | |
384 | BLKC_STORE(PRE, ctx->b, t); \ | |
385 | r = ctx->b; ctx->off = plan.tail; \ | |
386 | while (plan.tail--) { y = *p++; *q++ = y ^ *r; *r++ = y; } \ | |
387 | } \ | |
388 | \ | |
389 | /* Done. */ \ | |
390 | return (0); \ | |
391 | } \ | |
392 | \ | |
393 | /* --- @pre_ccmdecrypt@ --- * \ | |
394 | * \ | |
395 | * Arguments: @pre_ccmctx *ctx@ = pointer to CCM operation context \ | |
396 | * @const void *src@ = pointer to ciphertext message chunk \ | |
397 | * @size_t sz@ = size of the ciphertext \ | |
398 | * @buf *dst@ = a buffer to write the plaintext to \ | |
399 | * \ | |
400 | * Returns: Zero on success; @-1@ on failure. \ | |
401 | * \ | |
402 | * Use: Decrypts a chunk of a ciphertext message, writing a \ | |
403 | * chunk of plaintext to the output buffer and updating \ | |
404 | * the operation state. \ | |
405 | * \ | |
406 | * For CCM, we always write a plaintext chunk the same \ | |
407 | * size as the ciphertext. The messing about with @buf@ \ | |
408 | * objects makes the interface consistent with other AEAD \ | |
409 | * schemes which can't do this. \ | |
410 | */ \ | |
411 | \ | |
412 | int pre##_ccmdecrypt(pre##_ccmctx *ctx, \ | |
413 | const void *src, size_t sz, buf *dst) \ | |
414 | { \ | |
415 | rsvr_plan plan; \ | |
416 | uint32 t[PRE##_BLKSZ/4]; \ | |
417 | const octet *p = src; \ | |
418 | octet *q, *r, y; \ | |
419 | \ | |
420 | /* Allocate space for the plaintext. */ \ | |
421 | if (sz) { q = buf_get(dst, sz); if (!q) return (-1); } \ | |
422 | else q = 0; \ | |
423 | \ | |
424 | /* Set stuff up. */ \ | |
425 | pre##_ccmencdecsetup(ctx, sz); \ | |
426 | \ | |
427 | /* Determine the buffering plan. Our buffer is going to do double- \ | |
428 | * duty here. The end portion is going to contain mask from the \ | |
429 | * encrypted counter which we mix into the plaintext to encrypt it; \ | |
430 | * the start portion, which originally mask bytes we've already used, \ | |
431 | * will hold the recovered plaintext, which will eventually be \ | |
432 | * collected into the CBC-MAC state. \ | |
433 | */ \ | |
434 | rsvr_mkplan(&plan, &pre##_ccmpolicy, ctx->off, sz); \ | |
435 | \ | |
436 | /* Initial portion, fulfilled from the buffer. If the buffer is \ | |
437 | * empty, then that means that we haven't yet encrypted the current \ | |
438 | * counter, so we should do that and advance it. \ | |
439 | */ \ | |
440 | if (plan.head) { \ | |
441 | if (!ctx->off) { \ | |
442 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ | |
443 | BLKC_STORE(PRE, ctx->b, t); \ | |
444 | } \ | |
445 | r = ctx->b + ctx->off; ctx->off += plan.head; \ | |
446 | while (plan.head--) { y = *p++ ^ *r; *q++ = *r++ = y; } \ | |
447 | } \ | |
448 | \ | |
449 | /* If we've filled up the buffer then we need to cycle the MAC and \ | |
450 | * reset the offset. \ | |
451 | */ \ | |
452 | if (plan.from_rsvr) { \ | |
453 | BLKC_XLOAD(PRE, ctx->a, ctx->b); \ | |
454 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ | |
455 | ctx->off = 0; \ | |
456 | } \ | |
457 | \ | |
458 | /* Now to process the main body of the input. */ \ | |
459 | while (plan.from_input) { \ | |
460 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ | |
461 | BLKC_XLOAD(PRE, t, p); p += PRE##_BLKSZ; \ | |
462 | BLKC_STORE(PRE, q, t); q += PRE##_BLKSZ; \ | |
463 | BLKC_XMOVE(PRE, ctx->a, t); pre##_eblk(&ctx->k, ctx->a, ctx->a); \ | |
464 | plan.from_input -= PRE##_BLKSZ; \ | |
465 | } \ | |
466 | \ | |
467 | /* Finally, deal with any final portion. If there is one, we know \ | |
468 | * that the buffer is empty: we must have filled it above, or this \ | |
469 | * would all count as `initial' data. \ | |
470 | */ \ | |
471 | if (plan.tail) { \ | |
472 | BLKC_BSTEP(PRE, ctx->c); pre##_eblk(&ctx->k, ctx->c, t); \ | |
473 | BLKC_STORE(PRE, ctx->b, t); \ | |
474 | r = ctx->b; ctx->off = plan.tail; \ | |
475 | while (plan.tail--) { y = *p++ ^ *r; *q++ = *r++ = y; } \ | |
476 | } \ | |
477 | \ | |
478 | /* Done. */ \ | |
479 | return (0); \ | |
480 | } \ | |
481 | \ | |
482 | /* --- @pre_ccmtag@ --- * \ | |
483 | * \ | |
484 | * Arguments: @pre_ccmctx *ctx@ = pointer to an CCM context \ | |
485 | * @octet *t@ = where to write a (full-length) tag \ | |
486 | * @size_t tsz@ = size of the tag (to check) \ | |
487 | * \ | |
488 | * Returns: --- \ | |
489 | * \ | |
490 | * Use: Finishes an CCM operation, by calculating the tag. \ | |
491 | */ \ | |
492 | \ | |
493 | static void pre##_ccmtag(pre##_ccmctx *ctx, octet *t, size_t tsz) \ | |
494 | { \ | |
495 | /* Make sure we're in good shape. It's just about possible that \ | |
496 | * we're still in the AAD state, but there was no actual message, so \ | |
497 | * handle this situation. \ | |
498 | */ \ | |
499 | switch (ctx->st) { \ | |
500 | case CCMST_AAD: \ | |
501 | assert(ctx->i == ctx->p.hsz); \ | |
502 | assert(!ctx->p.msz); \ | |
503 | break; \ | |
504 | case CCMST_MSG: \ | |
505 | /* hsz already checked in `pre_ccmencdecsetup'. */ \ | |
506 | assert(ctx->i == ctx->p.msz); \ | |
507 | break; \ | |
508 | default: abort(); \ | |
509 | } \ | |
510 | assert(tsz == ctx->p.tsz); \ | |
511 | \ | |
512 | /* Pad the final plaintext block out and cycle the block cipher one \ | |
513 | * last time. \ | |
514 | */ \ | |
515 | memset(ctx->b + ctx->off, 0, PRE##_BLKSZ - ctx->off); \ | |
516 | BLKC_XLOAD(PRE, ctx->a, ctx->b); \ | |
517 | pre##_eblk(&ctx->k, ctx->a, ctx->a); \ | |
518 | \ | |
519 | /* Mask the CBC-MAC tag (which prevents the standard extension \ | |
520 | * attack) and store the result. \ | |
521 | */ \ | |
522 | BLKC_XSTORE(PRE, t, ctx->a, ctx->s0); \ | |
523 | } \ | |
524 | \ | |
525 | /* --- @pre_ccmencryptdone@ --- * \ | |
526 | * \ | |
527 | * Arguments: @pre_ccmctx *ctx@ = pointer to an CCM context \ | |
528 | * @buf *dst@ = buffer for remaining ciphertext \ | |
529 | * @void *tag@ = where to write the tag \ | |
530 | * @size_t tsz@ = length of tag to store \ | |
531 | * \ | |
532 | * Returns: Zero on success; @-1@ on failure. \ | |
533 | * \ | |
534 | * Use: Completes an CCM encryption operation. The @aad@ \ | |
535 | * pointer may be null if there is no additional \ | |
536 | * authenticated data. CCM doesn't buffer ciphertext, but \ | |
537 | * the output buffer is provided anyway for consistency \ | |
538 | * with other AEAD schemes which don't have this property; \ | |
539 | * the function will fail if the output buffer is broken. \ | |
540 | */ \ | |
541 | \ | |
542 | int pre##_ccmencryptdone(pre##_ccmctx *ctx, buf *dst, \ | |
543 | void *tag, size_t tsz) \ | |
544 | { \ | |
545 | octet t[PRE##_BLKSZ]; \ | |
546 | \ | |
547 | /* Some initial checks. */ \ | |
548 | if (!BOK(dst)) return (-1); \ | |
549 | \ | |
550 | /* Calculate and return the tag. */ \ | |
551 | pre##_ccmtag(ctx, t, tsz); \ | |
552 | memcpy(tag, t, tsz); \ | |
553 | \ | |
554 | /* Done. */ \ | |
555 | return (0); \ | |
556 | } \ | |
557 | \ | |
558 | /* --- @pre_ccmdecryptdone@ --- * \ | |
559 | * \ | |
560 | * Arguments: @pre_ccmctx *ctx@ = pointer to an CCM context \ | |
561 | * @buf *dst@ = buffer for remaining plaintext \ | |
562 | * @const void *tag@ = tag to verify \ | |
563 | * @size_t tsz@ = length of tag \ | |
564 | * \ | |
565 | * Returns: @+1@ for complete success; @0@ if tag verification \ | |
566 | * failed; @-1@ for other kinds of errors. \ | |
567 | * \ | |
568 | * Use: Completes an CCM decryption operation. The @aad@ \ | |
569 | * pointer may be null if there is no additional \ | |
570 | * authenticated data. CCM doesn't buffer plaintext, but \ | |
571 | * the output buffer is provided anyway for consistency \ | |
572 | * with other AEAD schemes which don't have this property; \ | |
573 | * the function will fail if the output buffer is broken. \ | |
574 | */ \ | |
575 | \ | |
576 | int pre##_ccmdecryptdone(pre##_ccmctx *ctx, buf *dst, \ | |
577 | const void *tag, size_t tsz) \ | |
578 | { \ | |
579 | octet t[PRE##_BLKSZ]; \ | |
580 | \ | |
581 | /* Some initial checks. */ \ | |
582 | if (!BOK(dst)) return (-1); \ | |
583 | \ | |
584 | /* Calculate and check the tag. */ \ | |
585 | pre##_ccmtag(ctx, t, tsz); \ | |
586 | if (!ct_memeq(tag, t, tsz)) return (0); \ | |
587 | else return (+1); \ | |
588 | } \ | |
589 | \ | |
590 | /* --- Generic AEAD interface --- */ \ | |
591 | \ | |
592 | typedef struct gctx { \ | |
593 | gaead_aad a; \ | |
594 | pre##_ccmctx ctx; \ | |
595 | } gctx; \ | |
596 | \ | |
597 | static void gahash(gaead_aad *a, const void *h, size_t hsz) \ | |
598 | { gctx *ctx = (gctx *)a; pre##_ccmaadhash(&ctx->ctx, h, hsz); } \ | |
599 | \ | |
600 | static void gadestroy(gaead_aad *a) { ; } \ | |
601 | \ | |
602 | static const gaead_aadops gaops = \ | |
603 | { &pre##_ccm, 0, gahash, gadestroy }; \ | |
604 | \ | |
605 | typedef struct gectx { \ | |
606 | gaead_enc e; \ | |
607 | gctx g; \ | |
608 | } gectx; \ | |
609 | \ | |
610 | static gaead_aad *geaad(gaead_enc *e) \ | |
611 | { gectx *enc = (gectx *)e; return (&enc->g.a); } \ | |
612 | \ | |
613 | static int gereinit(gaead_enc *e, const void *n, size_t nsz, \ | |
614 | size_t hsz, size_t msz, size_t tsz) \ | |
615 | { \ | |
616 | gectx *enc = (gectx *)e; \ | |
617 | return (pre##_ccmreinit(&enc->g.ctx, n, nsz, hsz, msz, tsz)); \ | |
618 | } \ | |
619 | \ | |
620 | static int geenc(gaead_enc *e, const void *m, size_t msz, buf *b) \ | |
621 | { \ | |
622 | gectx *enc = (gectx *)e; \ | |
623 | return (pre##_ccmencrypt(&enc->g.ctx, m, msz, b)); \ | |
624 | } \ | |
625 | \ | |
626 | static int gedone(gaead_enc *e, const gaead_aad *a, \ | |
627 | buf *b, void *t, size_t tsz) \ | |
628 | { \ | |
629 | gectx *enc = (gectx *)e; \ | |
630 | assert((!a && !enc->g.ctx.p.hsz) || a == &enc->g.a); \ | |
631 | return (pre##_ccmencryptdone(&enc->g.ctx, b, t, tsz)); \ | |
632 | } \ | |
633 | \ | |
634 | static void gedestroy(gaead_enc *e) \ | |
635 | { gectx *enc = (gectx *)e; BURN(*enc); S_DESTROY(enc); } \ | |
636 | \ | |
637 | static const gaead_encops geops = \ | |
638 | { &pre##_ccm, geaad, gereinit, geenc, gedone, gedestroy }; \ | |
639 | \ | |
640 | typedef struct gdctx { \ | |
641 | gaead_dec d; \ | |
642 | gctx g; \ | |
643 | } gdctx; \ | |
644 | \ | |
645 | static gaead_aad *gdaad(gaead_dec *d) \ | |
646 | { gdctx *dec = (gdctx *)d; return (&dec->g.a); } \ | |
647 | \ | |
648 | static int gdreinit(gaead_dec *d, const void *n, size_t nsz, \ | |
649 | size_t hsz, size_t csz, size_t tsz) \ | |
650 | { \ | |
651 | gdctx *dec = (gdctx *)d; \ | |
652 | return (pre##_ccmreinit(&dec->g.ctx, n, nsz, hsz, csz, tsz)); \ | |
653 | } \ | |
654 | \ | |
655 | static int gddec(gaead_dec *d, const void *c, size_t csz, buf *b) \ | |
656 | { \ | |
657 | gdctx *dec = (gdctx *)d; \ | |
658 | return (pre##_ccmdecrypt(&dec->g.ctx, c, csz, b)); \ | |
659 | } \ | |
660 | \ | |
661 | static int gddone(gaead_dec *d, const gaead_aad *a, \ | |
662 | buf *b, const void *t, size_t tsz) \ | |
663 | { \ | |
664 | gdctx *dec = (gdctx *)d; \ | |
665 | assert((!a && !dec->g.ctx.p.hsz) || a == &dec->g.a); \ | |
666 | return (pre##_ccmdecryptdone(&dec->g.ctx, b, t, tsz)); \ | |
667 | } \ | |
668 | \ | |
669 | static void gddestroy(gaead_dec *d) \ | |
670 | { gdctx *dec = (gdctx *)d; BURN(*dec); S_DESTROY(dec); } \ | |
671 | \ | |
672 | static const gaead_decops gdops = \ | |
673 | { &pre##_ccm, gdaad, gdreinit, gddec, gddone, gddestroy }; \ | |
674 | \ | |
675 | typedef struct gkctx { \ | |
676 | gaead_key k; \ | |
677 | pre##_ctx key; \ | |
678 | } gkctx; \ | |
679 | \ | |
680 | static gaead_enc *gkenc(const gaead_key *k, const void *n, size_t nsz, \ | |
681 | size_t hsz, size_t msz, size_t tsz) \ | |
682 | { \ | |
683 | gkctx *key = (gkctx *)k; \ | |
684 | gectx *enc = S_CREATE(gectx); \ | |
685 | \ | |
686 | enc->e.ops = &geops; enc->g.a.ops = &gaops; \ | |
687 | if (pre##_ccminit(&enc->g.ctx, &key->key, n, nsz, hsz, msz, tsz)) \ | |
688 | { gedestroy(&enc->e); return (0); } \ | |
689 | return (&enc->e); \ | |
690 | } \ | |
691 | \ | |
692 | static gaead_dec *gkdec(const gaead_key *k, const void *n, size_t nsz, \ | |
693 | size_t hsz, size_t csz, size_t tsz) \ | |
694 | { \ | |
695 | gkctx *key = (gkctx *)k; \ | |
696 | gdctx *dec = S_CREATE(gdctx); \ | |
697 | \ | |
698 | dec->d.ops = &gdops; dec->g.a.ops = &gaops; \ | |
699 | if (pre##_ccminit(&dec->g.ctx, &key->key, n, nsz, hsz, csz, tsz)) \ | |
700 | { gddestroy(&dec->d); return (0); } \ | |
701 | return (&dec->d); \ | |
702 | } \ | |
703 | \ | |
704 | static void gkdestroy(gaead_key *k) \ | |
705 | { gkctx *key = (gkctx *)k; BURN(*key); S_DESTROY(key); } \ | |
706 | \ | |
707 | static const gaead_keyops gkops = \ | |
708 | { &pre##_ccm, 0, gkenc, gkdec, gkdestroy }; \ | |
709 | \ | |
710 | static gaead_key *gckey(const void *k, size_t ksz) \ | |
711 | { \ | |
712 | gkctx *key = S_CREATE(gkctx); \ | |
713 | key->k.ops = &gkops; \ | |
714 | pre##_init(&key->key, k, ksz); \ | |
715 | return (&key->k); \ | |
716 | } \ | |
717 | \ | |
718 | const gcaead pre##_ccm = { \ | |
719 | name "-ccm", \ | |
720 | pre##_keysz, pre##_ccmnoncesz, pre##_ccmtagsz, \ | |
721 | PRE##_BLKSZ, 0, 0, \ | |
722 | AEADF_PCHSZ | AEADF_PCMSZ | AEADF_PCTSZ | \ | |
723 | AEADF_AADNDEP | AEADF_AADFIRST, \ | |
724 | gckey \ | |
725 | }; \ | |
726 | \ | |
727 | CCM_TESTX(PRE, pre, name, fname) | |
728 | ||
729 | /*----- Test rig ----------------------------------------------------------*/ | |
730 | ||
731 | #define CCM_TEST(PRE, pre) CCM_TESTX(PRE, pre, #pre, #pre) | |
732 | ||
733 | /* --- @CCM_TEST@ --- * | |
734 | * | |
735 | * Arguments: @PRE, pre@ = prefixes for the underlying block cipher | |
736 | * | |
737 | * Use: Standard test rig for CCM functions. | |
738 | */ | |
739 | ||
740 | #ifdef TEST_RIG | |
741 | ||
742 | #include <stdio.h> | |
743 | ||
744 | #include <mLib/dstr.h> | |
141c1284 | 745 | #include <mLib/macros.h> |
55b6b722 MW |
746 | #include <mLib/quis.h> |
747 | #include <mLib/testrig.h> | |
748 | ||
749 | #define CCM_TESTX(PRE, pre, name, fname) \ | |
750 | \ | |
751 | static int ccmverify(dstr *v) \ | |
752 | { \ | |
753 | pre##_ctx key; \ | |
754 | pre##_ccmctx ctx; \ | |
755 | int ok = 1, win; \ | |
756 | int i; \ | |
757 | octet *p; \ | |
758 | int szs[] = { 1, 7, 192, -1, 0 }, *ip; \ | |
759 | size_t hsz, msz; \ | |
760 | dstr d = DSTR_INIT, t = DSTR_INIT; \ | |
761 | buf b; \ | |
762 | \ | |
763 | dstr_ensure(&d, v[4].len > v[3].len ? v[4].len : v[3].len); \ | |
764 | dstr_ensure(&t, v[5].len); t.len = v[5].len; \ | |
765 | \ | |
766 | pre##_init(&key, v[0].buf, v[0].len); \ | |
767 | \ | |
768 | for (ip = szs; *ip; ip++) { \ | |
769 | \ | |
770 | pre##_ccminit(&ctx, &key, (octet *)v[1].buf, v[1].len, \ | |
771 | v[2].len, v[3].len, v[5].len); \ | |
772 | \ | |
773 | i = *ip; \ | |
774 | hsz = v[2].len; \ | |
775 | if (i == -1) i = hsz; \ | |
776 | if (i > hsz) continue; \ | |
777 | p = (octet *)v[2].buf; \ | |
778 | while (hsz) { \ | |
779 | if (i > hsz) i = hsz; \ | |
780 | pre##_ccmaadhash(&ctx, p, i); \ | |
781 | p += i; hsz -= i; \ | |
782 | } \ | |
783 | \ | |
784 | buf_init(&b, d.buf, d.sz); \ | |
785 | i = *ip; \ | |
786 | msz = v[3].len; \ | |
787 | if (i == -1) i = msz; \ | |
788 | if (i > msz) continue; \ | |
789 | p = (octet *)v[3].buf; \ | |
790 | while (msz) { \ | |
791 | if (i > msz) i = msz; \ | |
792 | if (pre##_ccmencrypt(&ctx, p, i, &b)) { \ | |
793 | puts("!! ccmencrypt reports failure"); \ | |
794 | goto fail_enc; \ | |
795 | } \ | |
796 | p += i; msz -= i; \ | |
797 | } \ | |
798 | \ | |
799 | if (pre##_ccmencryptdone(&ctx, &b, (octet *)t.buf, t.len)) { \ | |
800 | puts("!! ccmencryptdone reports failure"); \ | |
801 | goto fail_enc; \ | |
802 | } \ | |
803 | d.len = BLEN(&b); \ | |
804 | \ | |
805 | if (d.len != v[4].len || \ | |
141c1284 MW |
806 | MEMCMP(d.buf, !=, v[4].buf, v[4].len) || \ |
807 | MEMCMP(t.buf, !=, v[5].buf, v[5].len)) { \ | |
55b6b722 MW |
808 | fail_enc: \ |
809 | printf("\nfail encrypt:\n\tstep = %i", *ip); \ | |
810 | fputs("\n\tkey = ", stdout); type_hex.dump(&v[0], stdout); \ | |
811 | fputs("\n\tnonce = ", stdout); type_hex.dump(&v[1], stdout); \ | |
812 | fputs("\n\theader = ", stdout); type_hex.dump(&v[2], stdout); \ | |
813 | fputs("\n\tmessage = ", stdout); type_hex.dump(&v[3], stdout); \ | |
814 | fputs("\n\texp ct = ", stdout); type_hex.dump(&v[4], stdout); \ | |
815 | fputs("\n\tcalc ct = ", stdout); type_hex.dump(&d, stdout); \ | |
816 | fputs("\n\texp tag = ", stdout); type_hex.dump(&v[5], stdout); \ | |
817 | fputs("\n\tcalc tag = ", stdout); type_hex.dump(&t, stdout); \ | |
818 | putchar('\n'); \ | |
819 | ok = 0; \ | |
820 | } \ | |
821 | \ | |
822 | pre##_ccminit(&ctx, &key, (octet *)v[1].buf, v[1].len, \ | |
823 | v[2].len, v[4].len, v[5].len); \ | |
824 | \ | |
825 | i = *ip; \ | |
826 | hsz = v[2].len; \ | |
827 | if (i == -1) i = hsz; \ | |
828 | if (i > hsz) continue; \ | |
829 | p = (octet *)v[2].buf; \ | |
830 | while (hsz) { \ | |
831 | if (i > hsz) i = hsz; \ | |
832 | pre##_ccmaadhash(&ctx, p, i); \ | |
833 | p += i; hsz -= i; \ | |
834 | } \ | |
835 | \ | |
836 | buf_init(&b, d.buf, d.sz); \ | |
837 | i = *ip; \ | |
838 | msz = v[4].len; \ | |
839 | if (i == -1) i = msz; \ | |
840 | if (i > msz) continue; \ | |
841 | p = (octet *)v[4].buf; \ | |
842 | while (msz) { \ | |
843 | if (i > msz) i = msz; \ | |
844 | if (pre##_ccmdecrypt(&ctx, p, i, &b)) { \ | |
845 | puts("!! ccmdecrypt reports failure"); \ | |
846 | win = 0; goto fail_dec; \ | |
847 | } \ | |
848 | p += i; msz -= i; \ | |
849 | } \ | |
850 | \ | |
851 | win = pre##_ccmdecryptdone(&ctx, &b, (octet *)v[5].buf, v[5].len); \ | |
852 | if (win < 0) { \ | |
853 | puts("!! ccmdecryptdone reports failure"); \ | |
854 | goto fail_dec; \ | |
855 | } \ | |
856 | d.len = BLEN(&b); \ | |
857 | \ | |
858 | if (d.len != v[3].len || !win || \ | |
141c1284 | 859 | MEMCMP(d.buf, !=, v[3].buf, v[3].len)) { \ |
55b6b722 MW |
860 | fail_dec: \ |
861 | printf("\nfail decrypt:\n\tstep = %i", *ip); \ | |
862 | fputs("\n\tkey = ", stdout); type_hex.dump(&v[0], stdout); \ | |
863 | fputs("\n\tnonce = ", stdout); type_hex.dump(&v[1], stdout); \ | |
864 | fputs("\n\theader = ", stdout); type_hex.dump(&v[2], stdout); \ | |
865 | fputs("\n\tciphertext = ", stdout); type_hex.dump(&v[4], stdout); \ | |
866 | fputs("\n\texp pt = ", stdout); type_hex.dump(&v[3], stdout); \ | |
867 | fputs("\n\tcalc pt = ", stdout); type_hex.dump(&d, stdout); \ | |
868 | fputs("\n\ttag = ", stdout); type_hex.dump(&v[5], stdout); \ | |
869 | printf("\n\tverify %s", win ? "ok" : "FAILED"); \ | |
870 | putchar('\n'); \ | |
871 | ok = 0; \ | |
872 | } \ | |
873 | } \ | |
874 | \ | |
875 | dstr_destroy(&d); dstr_destroy(&t); \ | |
876 | return (ok); \ | |
877 | } \ | |
878 | \ | |
879 | static test_chunk aeaddefs[] = { \ | |
880 | { name "-ccm", ccmverify, \ | |
881 | { &type_hex, &type_hex, &type_hex, &type_hex, \ | |
882 | &type_hex, &type_hex, 0 } }, \ | |
883 | { 0, 0, { 0 } } \ | |
884 | }; \ | |
885 | \ | |
886 | int main(int argc, char *argv[]) \ | |
887 | { \ | |
888 | ego(argv[0]); \ | |
889 | test_run(argc, argv, aeaddefs, SRCDIR"/t/" fname); \ | |
890 | return (0); \ | |
891 | } | |
892 | ||
893 | #else | |
894 | # define CCM_TESTX(PRE, pre, name, fname) | |
895 | #endif | |
896 | ||
897 | /*----- That's all, folks -------------------------------------------------*/ | |
898 | ||
899 | #ifdef __cplusplus | |
900 | } | |
901 | #endif | |
902 | ||
903 | #endif |