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1 | /* -*-c-*- |
2 | * | |
3 | * The EAX 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_EAX_DEF_H | |
29 | #define CATACOMB_EAX_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_CMAC_H | |
55 | # include "cmac.h" | |
56 | #endif | |
57 | ||
58 | #ifndef CATACOMB_CMAC_DEF_H | |
59 | # include "cmac-def.h" | |
60 | #endif | |
61 | ||
62 | #ifndef CATACOMB_KEYSZ_H | |
63 | # include "keysz.h" | |
64 | #endif | |
65 | ||
66 | #ifndef CATACOMB_PARANOIA_H | |
67 | # include "paranoia.h" | |
68 | #endif | |
69 | ||
70 | #ifndef CATACOMB_RSVR_H | |
71 | # include "rsvr.h" | |
72 | #endif | |
73 | ||
74 | /*----- Macros ------------------------------------------------------------*/ | |
75 | ||
76 | /* --- @EAX_DEF@ --- * | |
77 | * | |
78 | * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher | |
79 | * | |
80 | * Use: Creates an implementation for the EAX authenticated- | |
81 | * encryption mode. | |
82 | */ | |
83 | ||
84 | #define EAX_DEF(PRE, pre) EAX_DEFX(PRE, pre, #pre, #pre) | |
85 | ||
86 | #define EAX_DEFX(PRE, pre, name, fname) \ | |
87 | \ | |
88 | OMAC_DECL(PRE, pre) \ | |
89 | \ | |
90 | const octet \ | |
91 | pre##_eaxnoncesz[] = { KSZ_ANY, PRE##_BLKSZ }, \ | |
92 | pre##_eaxtagsz[] = { KSZ_RANGE, PRE##_BLKSZ, 0, PRE##_BLKSZ, 1 }; \ | |
93 | \ | |
94 | /* --- @pre_eaxsetkey@ --- * \ | |
95 | * \ | |
96 | * Arguments: @pre_eaxkey *key@ = pointer to key block to fill in \ | |
97 | * @const void *k@ = pointer to key material \ | |
98 | * @size_t ksz@ = size of key material \ | |
99 | * \ | |
100 | * Returns: --- \ | |
101 | * \ | |
102 | * Use: Initializes an EAX key block. \ | |
103 | */ \ | |
104 | \ | |
105 | void pre##_eaxsetkey(pre##_eaxkey *key, const void *k, size_t ksz) \ | |
106 | { \ | |
107 | uint32 t[PRE##_BLKSZ/4]; \ | |
108 | \ | |
109 | /* Initialize the block cipher. */ \ | |
110 | pre##_init(&key->ctx, k, ksz); \ | |
111 | \ | |
112 | /* Set up the OMAC masks. */ \ | |
113 | pre##_omacmasks(&key->ctx, key->m0, key->m1); \ | |
114 | \ | |
115 | /* Set up the OMAC tweaks. EAX tweaks its MAC by simply stitching \ | |
116 | * magic block-wide prefixes %$t_0$%, %$t_1$%, %$t_2$% (which are \ | |
117 | * simply the numbers 0, 1, 2) on the front of strings. We can \ | |
118 | * accelerate things by caching two values for each tweak: \ | |
119 | * \ | |
120 | * * %$v_i = E_K(t_i)$% is the accumulator that results from \ | |
121 | * pushing the tweak through the blockcipher, which we'd \ | |
122 | * calculate if the original message was nonempty. \ | |
123 | * \ | |
124 | * * %$z_i = E_K(t_0 \xor m_0)$% is the tweak with the `full final \ | |
125 | * buffer' mask applied, which is the final tag for a final empty \ | |
126 | * message. \ | |
127 | */ \ | |
128 | BLKC_BSET(PRE, t, 0); pre##_eblk(&key->ctx, t, key->v0); \ | |
129 | BLKC_XMOVE(PRE, t, key->m0); pre##_eblk(&key->ctx, t, key->z0); \ | |
130 | BLKC_BSET(PRE, t, 1); pre##_eblk(&key->ctx, t, key->v1); \ | |
131 | BLKC_XMOVE(PRE, t, key->m0); pre##_eblk(&key->ctx, t, key->z1); \ | |
132 | BLKC_BSET(PRE, t, 2); pre##_eblk(&key->ctx, t, key->v2); \ | |
133 | BLKC_XMOVE(PRE, t, key->m0); pre##_eblk(&key->ctx, t, key->z2); \ | |
134 | } \ | |
135 | \ | |
136 | /* --- @pre_eaxaadinit@ --- * \ | |
137 | * \ | |
138 | * Arguments: @pre_eaxaadctx *aad@ = pointer to AAD context \ | |
139 | * @const pre_eaxkey *key@ = pointer to key block \ | |
140 | * \ | |
141 | * Returns: --- \ | |
142 | * \ | |
143 | * Use: Initializes an EAX AAD (`additional authenticated \ | |
144 | * data') context associated with a given key. AAD \ | |
145 | * contexts can be copied and/or reused, saving time if \ | |
146 | * the AAD for a number of messages has a common prefix. \ | |
147 | * \ | |
148 | * The @key@ doesn't need to be kept around, though \ | |
149 | * usually there'll at least be another copy in some EAX \ | |
150 | * operation context because the AAD on its own isn't much \ | |
151 | * good. \ | |
152 | */ \ | |
153 | \ | |
154 | void pre##_eaxaadinit(pre##_eaxaadctx *aad, const pre##_eaxkey *key) \ | |
155 | { aad->k = *key; aad->off = 0; BLKC_MOVE(PRE, aad->a, key->v1); } \ | |
156 | \ | |
157 | /* --- @pre_eaxaadhash@ --- * \ | |
158 | * \ | |
159 | * Arguments: @pre_eaxaadctx *aad@ = pointer to AAD context \ | |
160 | * @const void *p@ = pointer to AAD material \ | |
161 | * @size_t sz@ = length of AAD material \ | |
162 | * \ | |
163 | * Returns: --- \ | |
164 | * \ | |
165 | * Use: Feeds AAD into the context. \ | |
166 | */ \ | |
167 | \ | |
168 | void pre##_eaxaadhash(pre##_eaxaadctx *aad, const void *p, size_t sz) \ | |
169 | { \ | |
170 | rsvr_state st; \ | |
171 | const octet *q; \ | |
172 | \ | |
173 | rsvr_setup(&st, &pre##_omacpolicy, aad->b, &aad->off, p, sz); \ | |
174 | RSVR_DO(&st) while ((q = RSVR_NEXT(&st, PRE##_BLKSZ)) != 0) \ | |
175 | OMAC_BLOCK(PRE, pre, &aad->k.ctx, aad->a, q); \ | |
176 | } \ | |
177 | \ | |
178 | /* --- @pre_eaxinit@ --- * \ | |
179 | * \ | |
180 | * Arguments: @pre_eaxctx *ctx@ = pointer to EAX context \ | |
181 | * @const pre_eaxkey *key@ = pointer to key block \ | |
182 | * @const void *n@ = pointer to nonce \ | |
183 | * @size_t nsz@ = size of nonce \ | |
184 | * \ | |
185 | * Returns: --- \ | |
186 | * \ | |
187 | * Use: Initialize an EAX operation context with a given key. \ | |
188 | * \ | |
189 | * The original key needn't be kept around any more. \ | |
190 | */ \ | |
191 | \ | |
192 | void pre##_eaxinit(pre##_eaxctx *ctx, const pre##_eaxkey *k, \ | |
193 | const void *n, size_t nsz) \ | |
194 | { ctx->k = *k; pre##_eaxreinit(ctx, n, nsz); } \ | |
195 | \ | |
196 | /* --- @pre_eaxreinit@ --- * \ | |
197 | * \ | |
198 | * Arguments: @pre_eaxctx *ctx@ = pointer to EAX context \ | |
199 | * @const void *n@ = pointer to nonce \ | |
200 | * @size_t nsz@ = size of nonce \ | |
201 | * \ | |
202 | * Returns: --- \ | |
203 | * \ | |
204 | * Use: Reinitialize an EAX operation context, changing the \ | |
205 | * nonce. \ | |
206 | */ \ | |
207 | \ | |
208 | void pre##_eaxreinit(pre##_eaxctx *ctx, const void *n, size_t nsz) \ | |
209 | { \ | |
210 | octet b[PRE##_BLKSZ]; \ | |
211 | const octet *q = n; \ | |
212 | \ | |
213 | /* Initialize the OMAC context with the right tweak. */ \ | |
214 | BLKC_MOVE(PRE, ctx->a, ctx->k.v2); \ | |
215 | ctx->off = 0; \ | |
216 | \ | |
217 | /* Calculate the initial counter from the nonce. This is OMAC again, \ | |
218 | * but this time we know that we're starting from a clean slate and \ | |
219 | * we have the whole input in one go, so we don't bother with the \ | |
220 | * full reservoir machinery. \ | |
221 | */ \ | |
222 | if (!nsz) \ | |
223 | BLKC_MOVE(PRE, ctx->c0, ctx->k.z0); \ | |
224 | else { \ | |
225 | BLKC_MOVE(PRE, ctx->c0, ctx->k.v0); \ | |
226 | while (nsz > PRE##_BLKSZ) { \ | |
227 | OMAC_BLOCK(PRE, pre, &ctx->k.ctx, ctx->c0, q); \ | |
228 | q += PRE##_BLKSZ; nsz -= PRE##_BLKSZ; \ | |
229 | } \ | |
230 | memcpy(b, q, nsz); \ | |
231 | pre##_omacdone(&ctx->k.ctx, ctx->k.m0, ctx->k.m1, \ | |
232 | ctx->c0, b, nsz); \ | |
233 | } \ | |
234 | \ | |
235 | /* We must remember the initial counter for the final tag \ | |
236 | * calculation. (I conjecture that storing the final counter instead \ | |
237 | * would be just as secure, and require less state, but I've not \ | |
238 | * proven this, and anyway it wouldn't interoperate.) Copy it to \ | |
239 | * make the working counter. \ | |
240 | */ \ | |
241 | BLKC_MOVE(PRE, ctx->c, ctx->c0); \ | |
242 | } \ | |
243 | \ | |
244 | /* --- @pre_eaxencrypt@ --- * \ | |
245 | * \ | |
246 | * Arguments: @pre_eaxctx *ctx@ = pointer to EAX operation context \ | |
247 | * @const void *src@ = pointer to plaintext message chunk \ | |
248 | * @size_t sz@ = size of the plaintext \ | |
249 | * @buf *dst@ = a buffer to write the ciphertext to \ | |
250 | * \ | |
251 | * Returns: Zero on success; @-1@ on failure. \ | |
252 | * \ | |
253 | * Use: Encrypts a chunk of a plaintext message, writing a \ | |
254 | * chunk of ciphertext to the output buffer and updating \ | |
255 | * the operation state. \ | |
256 | * \ | |
257 | * For EAX, we always write a ciphertext chunk the same \ | |
258 | * size as the plaintext. The messing about with @buf@ \ | |
259 | * objects makes the interface consistent with other AEAD \ | |
260 | * schemes which can't do this. \ | |
261 | */ \ | |
262 | \ | |
263 | int pre##_eaxencrypt(pre##_eaxctx *ctx, \ | |
264 | const void *src, size_t sz, buf *dst) \ | |
265 | { \ | |
266 | rsvr_plan plan; \ | |
267 | uint32 t[PRE##_BLKSZ/4]; \ | |
268 | const octet *p = src; \ | |
269 | octet *q, *r, y; \ | |
270 | \ | |
271 | /* Allocate space for the ciphertext. */ \ | |
272 | if (sz) { q = buf_get(dst, sz); if (!q) return (-1); } \ | |
273 | else q = 0; \ | |
274 | \ | |
275 | /* Determine the buffering plan. Our buffer is going to do double- \ | |
276 | * duty here. The end portion is going to contain mask from the \ | |
277 | * encrypted counter which we mix into the plaintext to encrypt it; \ | |
278 | * the start portion, which originally mask bytes we've already used, \ | |
279 | * will hold the output ciphertext, which will eventually be \ | |
280 | * collected into the OMAC state. \ | |
281 | */ \ | |
282 | rsvr_mkplan(&plan, &pre##_omacpolicy, ctx->off, sz); \ | |
283 | \ | |
284 | /* Initial portion, fulfilled from the buffer. If the buffer is \ | |
285 | * empty, then that means that we haven't yet encrypted the current \ | |
286 | * counter, so we should do that and advance it. \ | |
287 | */ \ | |
288 | if (plan.head) { \ | |
289 | if (!ctx->off) { \ | |
290 | pre##_eblk(&ctx->k.ctx, ctx->c, t); BLKC_BSTEP(PRE, ctx->c); \ | |
291 | BLKC_STORE(PRE, ctx->b, t); \ | |
292 | } \ | |
293 | r = ctx->b + ctx->off; ctx->off += plan.head; \ | |
294 | while (plan.head--) { y = *p++ ^ *r; *r++ = *q++ = y; } \ | |
295 | } \ | |
296 | \ | |
297 | /* If we've filled up the buffer then we need to cycle the MAC and \ | |
298 | * reset the offset. \ | |
299 | */ \ | |
300 | if (plan.from_rsvr) { \ | |
301 | OMAC_BLOCK(PRE, pre, &ctx->k.ctx, ctx->a, ctx->b); \ | |
302 | ctx->off = 0; \ | |
303 | } \ | |
304 | \ | |
305 | /* Now to process the main body of the input. We sneakily open-code \ | |
306 | * the OMAC part of this. \ | |
307 | */ \ | |
308 | while (plan.from_input) { \ | |
309 | pre##_eblk(&ctx->k.ctx, ctx->c, t); BLKC_BSTEP(PRE, ctx->c); \ | |
310 | BLKC_XLOAD(PRE, t, p); p += PRE##_BLKSZ; \ | |
311 | BLKC_STORE(PRE, q, t); q += PRE##_BLKSZ; \ | |
312 | BLKC_XMOVE(PRE, ctx->a, t); pre##_eblk(&ctx->k.ctx, ctx->a, ctx->a); \ | |
313 | plan.from_input -= PRE##_BLKSZ; \ | |
314 | } \ | |
315 | \ | |
316 | /* Finally, deal with any final portion. If there is one, we know \ | |
317 | * that the buffer is empty: we must have filled it above, or this \ | |
318 | * would all count as `initial' data. \ | |
319 | */ \ | |
320 | if (plan.tail) { \ | |
321 | pre##_eblk(&ctx->k.ctx, ctx->c, t); BLKC_BSTEP(PRE, ctx->c); \ | |
322 | BLKC_STORE(PRE, ctx->b, t); \ | |
323 | r = ctx->b; ctx->off += plan.tail; \ | |
324 | while (plan.tail--) { y = *p++ ^ *r; *r++ = *q++ = y; } \ | |
325 | } \ | |
326 | \ | |
327 | /* And we're done. */ \ | |
328 | return (0); \ | |
329 | } \ | |
330 | \ | |
331 | /* --- @pre_eaxdecrypt@ --- * \ | |
332 | * \ | |
333 | * Arguments: @pre_eaxctx *ctx@ = pointer to EAX operation context \ | |
334 | * @const void *src@ = pointer to ciphertext message chunk \ | |
335 | * @size_t sz@ = size of the ciphertext \ | |
336 | * @buf *dst@ = a buffer to write the plaintext to \ | |
337 | * \ | |
338 | * Returns: Zero on success; @-1@ on failure. \ | |
339 | * \ | |
340 | * Use: Decrypts a chunk of a ciphertext message, writing a \ | |
341 | * chunk of plaintext to the output buffer and updating \ | |
342 | * the operation state. \ | |
343 | * \ | |
344 | * For EAX, we always write a plaintext chunk the same \ | |
345 | * size as the ciphertext. The messing about with @buf@ \ | |
346 | * objects makes the interface consistent with other AEAD \ | |
347 | * schemes which can't do this. \ | |
348 | */ \ | |
349 | \ | |
350 | int pre##_eaxdecrypt(pre##_eaxctx *ctx, \ | |
351 | const void *src, size_t sz, buf *dst) \ | |
352 | { \ | |
353 | rsvr_plan plan; \ | |
354 | uint32 t[PRE##_BLKSZ/4], u[PRE##_BLKSZ]; \ | |
355 | const octet *p = src; \ | |
356 | octet *q, *r, y; \ | |
357 | \ | |
358 | /* Allocate space for the plaintext. */ \ | |
359 | if (sz) { q = buf_get(dst, sz); if (!q) return (-1); } \ | |
360 | else q = 0; \ | |
361 | \ | |
362 | /* Determine the buffering plan. Our buffer is going to do double- \ | |
363 | * duty here. The end portion is going to contain mask from the \ | |
364 | * encrypted counter which we mix into the plaintext to encrypt it; \ | |
365 | * the start portion, which originally mask bytes we've already used, \ | |
366 | * will hold the input ciphertext, which will eventually be \ | |
367 | * collected into the OMAC state. \ | |
368 | */ \ | |
369 | rsvr_mkplan(&plan, &pre##_omacpolicy, ctx->off, sz); \ | |
370 | \ | |
371 | /* Initial portion, fulfilled from the buffer. If the buffer is \ | |
372 | * empty, then that means that we haven't yet encrypted the current \ | |
373 | * counter, so we should do that and advance it. \ | |
374 | */ \ | |
375 | if (plan.head) { \ | |
376 | if (!ctx->off) { \ | |
377 | pre##_eblk(&ctx->k.ctx, ctx->c, t); BLKC_BSTEP(PRE, ctx->c); \ | |
378 | BLKC_STORE(PRE, ctx->b, t); \ | |
379 | } \ | |
380 | r = ctx->b + ctx->off; ctx->off += plan.head; \ | |
381 | while (plan.head--) { y = *p++; *q++ = y ^ *r; *r++ = y; } \ | |
382 | } \ | |
383 | \ | |
384 | /* If we've filled up the buffer then we need to cycle the MAC and \ | |
385 | * reset the offset. \ | |
386 | */ \ | |
387 | if (plan.from_rsvr) { \ | |
388 | OMAC_BLOCK(PRE, pre, &ctx->k.ctx, ctx->a, ctx->b); \ | |
389 | ctx->off = 0; \ | |
390 | } \ | |
391 | \ | |
392 | /* Now to process the main body of the input. We sneakily open-code \ | |
393 | * the OMAC part of this. \ | |
394 | */ \ | |
395 | while (plan.from_input) { \ | |
396 | pre##_eblk(&ctx->k.ctx, ctx->c, t); BLKC_BSTEP(PRE, ctx->c); \ | |
397 | BLKC_LOAD(PRE, u, p); p += PRE##_BLKSZ; \ | |
398 | BLKC_XSTORE(PRE, q, t, u); q += PRE##_BLKSZ; \ | |
399 | BLKC_XMOVE(PRE, ctx->a, u); pre##_eblk(&ctx->k.ctx, ctx->a, ctx->a); \ | |
400 | plan.from_input -= PRE##_BLKSZ; \ | |
401 | } \ | |
402 | \ | |
403 | /* Finally, deal with any final portion. If there is one, we know \ | |
404 | * that the buffer is empty: we must have filled it above, or this \ | |
405 | * would all count as `initial' data. \ | |
406 | */ \ | |
407 | if (plan.tail) { \ | |
408 | pre##_eblk(&ctx->k.ctx, ctx->c, t); BLKC_BSTEP(PRE, ctx->c); \ | |
409 | BLKC_STORE(PRE, ctx->b, t); \ | |
410 | r = ctx->b; ctx->off += plan.tail; \ | |
411 | while (plan.tail--) { y = *p++; *q++ = y ^ *r; *r++ = y; } \ | |
412 | } \ | |
413 | \ | |
414 | /* And we're done. */ \ | |
415 | return (0); \ | |
416 | } \ | |
417 | \ | |
418 | /* --- @pre_eaxtag@ --- * \ | |
419 | * \ | |
420 | * Arguments: @pre_eaxctx *ctx@ = pointer to an EAX context \ | |
421 | * @const pre_eaxaadctx *aad@ = pointer to AAD context, or \ | |
422 | * null \ | |
423 | * @octet *t@ = where to write a (full-length) tag \ | |
424 | * \ | |
425 | * Returns: --- \ | |
426 | * \ | |
427 | * Use: Finishes an EAX operation, by calculating the tag. \ | |
428 | */ \ | |
429 | \ | |
430 | static void pre##_eaxtag(pre##_eaxctx *ctx, \ | |
431 | const pre##_eaxaadctx *aad, octet *t) \ | |
432 | { \ | |
433 | octet b[PRE##_BLKSZ]; \ | |
434 | uint32 u[PRE##_BLKSZ/4]; \ | |
435 | \ | |
436 | /* Finish tagging the ciphertext. (The buffer is empty if and only \ | |
437 | * if there was no message, since the OMAC reservoir policy leaves \ | |
438 | * the buffer full.) \ | |
439 | */ \ | |
440 | if (!ctx->off) BLKC_MOVE(PRE, ctx->a, ctx->k.z2); \ | |
441 | else pre##_omacdone(&ctx->k.ctx, ctx->k.m0, ctx->k.m1, \ | |
442 | ctx->a, ctx->b, ctx->off); \ | |
443 | \ | |
444 | /* If there's no AAD, because the pointer is null or no data was \ | |
445 | * supplied, then use the cached empty-header tag. Otherwise \ | |
446 | * calculate the tag for the AAD. Either way, mix the result into \ | |
447 | * ctx->A, and be careful not to modify the AAD context. (Again, the \ | |
448 | * buffer is empty if and only if there was no AAD.) \ | |
449 | */ \ | |
450 | if (!aad || !aad->off) BLKC_XMOVE(PRE, ctx->a, ctx->k.z1); \ | |
451 | else { \ | |
452 | BLKC_MOVE(PRE, u, aad->a); memcpy(b, aad->b, aad->off); \ | |
453 | pre##_omacdone(&ctx->k.ctx, ctx->k.m0, ctx->k.m1, u, b, aad->off); \ | |
454 | BLKC_XMOVE(PRE, ctx->a, u); \ | |
455 | } \ | |
456 | \ | |
457 | /* Finally, mix in the initial counter value. */ \ | |
458 | BLKC_XMOVE(PRE, ctx->a, ctx->c0); \ | |
459 | \ | |
460 | /* We're done. */ \ | |
461 | BLKC_STORE(PRE, t, ctx->a); \ | |
462 | } \ | |
463 | \ | |
464 | /* --- @pre_eaxencryptdone@ --- * \ | |
465 | * \ | |
466 | * Arguments: @pre_eaxctx *ctx@ = pointer to an EAX context \ | |
467 | * @const pre_eaxaadctx *aad@ = pointer to AAD context, or \ | |
468 | * null \ | |
469 | * @buf *dst@ = buffer for remaining ciphertext \ | |
470 | * @void *tag@ = where to write the tag \ | |
471 | * @size_t tsz@ = length of tag to store \ | |
472 | * \ | |
473 | * Returns: Zero on success; @-1@ on failure. \ | |
474 | * \ | |
475 | * Use: Completes an EAX encryption operation. The @aad@ \ | |
476 | * pointer may be null if there is no additional \ | |
477 | * authenticated data. EAX doesn't buffer ciphertext, but \ | |
478 | * the output buffer is provided anyway for consistency \ | |
479 | * with other AEAD schemes which don't have this property; \ | |
480 | * the function will fail if the output buffer is broken. \ | |
481 | */ \ | |
482 | \ | |
483 | int pre##_eaxencryptdone(pre##_eaxctx *ctx, \ | |
484 | const pre##_eaxaadctx *aad, buf *dst, \ | |
485 | void *tag, size_t tsz) \ | |
486 | { \ | |
487 | octet t[PRE##_BLKSZ]; \ | |
488 | \ | |
489 | if (tsz > PRE##_BLKSZ) return (-1); \ | |
490 | if (!BOK(dst)) return (-1); \ | |
491 | pre##_eaxtag(ctx, aad, t); memcpy(tag, t, tsz); \ | |
492 | return (0); \ | |
493 | } \ | |
494 | \ | |
495 | /* --- @pre_eaxdecryptdone@ --- * \ | |
496 | * \ | |
497 | * Arguments: @pre_eaxctx *ctx@ = pointer to an EAX context \ | |
498 | * @const pre_eaxaadctx *aad@ = pointer to AAD context, or \ | |
499 | * null \ | |
500 | * @buf *dst@ = buffer for remaining plaintext \ | |
501 | * @const void *tag@ = tag to verify \ | |
502 | * @size_t tsz@ = length of tag \ | |
503 | * \ | |
504 | * Returns: @+1@ for complete success; @0@ if tag verification \ | |
505 | * failed; @-1@ for other kinds of errors. \ | |
506 | * \ | |
507 | * Use: Completes an EAX decryption operation. The @aad@ \ | |
508 | * pointer may be null if there is no additional \ | |
509 | * authenticated data. EAX doesn't buffer plaintext, but \ | |
510 | * the output buffer is provided anyway for consistency \ | |
511 | * with other AEAD schemes which don't have this property; \ | |
512 | * the function will fail if the output buffer is broken. \ | |
513 | */ \ | |
514 | \ | |
515 | int pre##_eaxdecryptdone(pre##_eaxctx *ctx, \ | |
516 | const pre##_eaxaadctx *aad, buf *dst, \ | |
517 | const void *tag, size_t tsz) \ | |
518 | { \ | |
519 | octet t[PRE##_BLKSZ]; \ | |
520 | \ | |
521 | if (tsz > PRE##_BLKSZ) return (-1); \ | |
522 | if (!BOK(dst)) return (-1); \ | |
523 | pre##_eaxtag(ctx, aad, t); \ | |
524 | if (!ct_memeq(tag, t, tsz)) return (0); \ | |
525 | else return (+1); \ | |
526 | } \ | |
527 | \ | |
528 | /* --- Generic AEAD interface --- */ \ | |
529 | \ | |
530 | typedef struct gactx { \ | |
531 | gaead_aad a; \ | |
532 | pre##_eaxaadctx aad; \ | |
533 | } gactx; \ | |
534 | \ | |
535 | \ | |
536 | static gaead_aad *gadup(const gaead_aad *a) \ | |
537 | { gactx *aad = S_CREATE(gactx); *aad = *(gactx *)a; return (&aad->a); } \ | |
538 | \ | |
539 | static void gahash(gaead_aad *a, const void *h, size_t hsz) \ | |
540 | { gactx *aad = (gactx *)a; pre##_eaxaadhash(&aad->aad, h, hsz); } \ | |
541 | \ | |
542 | static void gadestroy(gaead_aad *a) \ | |
543 | { gactx *aad = (gactx *)a; BURN(*aad); S_DESTROY(aad); } \ | |
544 | \ | |
545 | static const gaead_aadops gaops = \ | |
546 | { &pre##_eax, gadup, gahash, gadestroy }; \ | |
547 | \ | |
548 | static gaead_aad *gaad(const pre##_eaxkey *k) \ | |
549 | { \ | |
550 | gactx *aad = S_CREATE(gactx); \ | |
551 | aad->a.ops = &gaops; \ | |
552 | pre##_eaxaadinit(&aad->aad, k); \ | |
553 | return (&aad->a); \ | |
554 | } \ | |
555 | \ | |
556 | typedef struct gectx { \ | |
557 | gaead_enc e; \ | |
558 | pre##_eaxctx ctx; \ | |
559 | } gectx; \ | |
560 | \ | |
561 | static gaead_aad *geaad(gaead_enc *e) \ | |
562 | { gectx *enc = (gectx *)e; return (gaad(&enc->ctx.k)); } \ | |
563 | \ | |
564 | static int gereinit(gaead_enc *e, const void *n, size_t nsz, \ | |
565 | size_t hsz, size_t msz, size_t tsz) \ | |
566 | { \ | |
567 | gectx *enc = (gectx *)e; \ | |
568 | \ | |
569 | if (tsz > PRE##_BLKSZ) return (-1); \ | |
570 | pre##_eaxreinit(&enc->ctx, n, nsz); \ | |
571 | return (0); \ | |
572 | } \ | |
573 | \ | |
574 | static int geenc(gaead_enc *e, const void *m, size_t msz, buf *b) \ | |
575 | { \ | |
576 | gectx *enc = (gectx *)e; \ | |
577 | return (pre##_eaxencrypt(&enc->ctx, m, msz, b)); \ | |
578 | } \ | |
579 | \ | |
580 | static int gedone(gaead_enc *e, const gaead_aad *a, \ | |
581 | buf *b, void *t, size_t tsz) \ | |
582 | { \ | |
583 | gectx *enc = (gectx *)e; gactx *aad = (gactx *)a; \ | |
584 | assert(!a || a->ops == &gaops); \ | |
585 | return (pre##_eaxencryptdone(&enc->ctx, a ? &aad->aad : 0, b, t, tsz)); \ | |
586 | } \ | |
587 | \ | |
588 | static void gedestroy(gaead_enc *e) \ | |
589 | { gectx *enc = (gectx *)e; BURN(*enc); S_DESTROY(enc); } \ | |
590 | \ | |
591 | static const gaead_encops geops = \ | |
592 | { &pre##_eax, geaad, gereinit, geenc, gedone, gedestroy }; \ | |
593 | \ | |
594 | typedef struct gdctx { \ | |
595 | gaead_dec d; \ | |
596 | pre##_eaxctx ctx; \ | |
597 | } gdctx; \ | |
598 | \ | |
599 | static gaead_aad *gdaad(gaead_dec *d) \ | |
600 | { gdctx *dec = (gdctx *)d; return (gaad(&dec->ctx.k)); } \ | |
601 | \ | |
602 | static int gdreinit(gaead_dec *d, const void *n, size_t nsz, \ | |
603 | size_t hsz, size_t csz, size_t tsz) \ | |
604 | { \ | |
605 | gdctx *dec = (gdctx *)d; \ | |
606 | \ | |
607 | if (tsz > PRE##_BLKSZ) return (-1); \ | |
608 | pre##_eaxreinit(&dec->ctx, n, nsz); \ | |
609 | return (0); \ | |
610 | } \ | |
611 | \ | |
612 | static int gddec(gaead_dec *d, const void *c, size_t csz, buf *b) \ | |
613 | { \ | |
614 | gdctx *dec = (gdctx *)d; \ | |
615 | return (pre##_eaxdecrypt(&dec->ctx, c, csz, b)); \ | |
616 | } \ | |
617 | \ | |
618 | static int gddone(gaead_dec *d, const gaead_aad *a, \ | |
619 | buf *b, const void *t, size_t tsz) \ | |
620 | { \ | |
621 | gdctx *dec = (gdctx *)d; gactx *aad = (gactx *)a; \ | |
622 | assert(!a || a->ops == &gaops); \ | |
623 | return (pre##_eaxdecryptdone(&dec->ctx, a ? &aad->aad : 0, b, t, tsz)); \ | |
624 | } \ | |
625 | \ | |
626 | static void gddestroy(gaead_dec *d) \ | |
627 | { gdctx *dec = (gdctx *)d; BURN(*dec); S_DESTROY(dec); } \ | |
628 | \ | |
629 | static const gaead_decops gdops = \ | |
630 | { &pre##_eax, gdaad, gdreinit, gddec, gddone, gddestroy }; \ | |
631 | \ | |
632 | typedef struct gkctx { \ | |
633 | gaead_key k; \ | |
634 | pre##_eaxkey key; \ | |
635 | } gkctx; \ | |
636 | \ | |
637 | static gaead_aad *gkaad(const gaead_key *k) \ | |
638 | { gkctx *key = (gkctx *)k; return (gaad(&key->key)); } \ | |
639 | \ | |
640 | static gaead_enc *gkenc(const gaead_key *k, const void *n, size_t nsz, \ | |
641 | size_t hsz, size_t msz, size_t tsz) \ | |
642 | { \ | |
643 | gkctx *key = (gkctx *)k; \ | |
644 | gectx *enc; \ | |
645 | \ | |
646 | if (tsz > PRE##_BLKSZ) return (0); \ | |
647 | enc = S_CREATE(gectx); enc->e.ops = &geops; \ | |
648 | pre##_eaxinit(&enc->ctx, &key->key, n, nsz); \ | |
649 | return (&enc->e); \ | |
650 | } \ | |
651 | \ | |
652 | static gaead_dec *gkdec(const gaead_key *k, const void *n, size_t nsz, \ | |
653 | size_t hsz, size_t csz, size_t tsz) \ | |
654 | { \ | |
655 | gkctx *key = (gkctx *)k; \ | |
656 | gdctx *dec; \ | |
657 | \ | |
658 | if (tsz > PRE##_BLKSZ) return (0); \ | |
659 | dec = S_CREATE(gdctx); dec->d.ops = &gdops; \ | |
660 | pre##_eaxinit(&dec->ctx, &key->key, n, nsz); \ | |
661 | return (&dec->d); \ | |
662 | } \ | |
663 | \ | |
664 | static void gkdestroy(gaead_key *k) \ | |
665 | { gkctx *key = (gkctx *)k; BURN(*key); S_DESTROY(key); } \ | |
666 | \ | |
667 | static const gaead_keyops gkops = \ | |
668 | { &pre##_eax, gkaad, gkenc, gkdec, gkdestroy }; \ | |
669 | \ | |
670 | static gaead_key *gckey(const void *k, size_t ksz) \ | |
671 | { \ | |
672 | gkctx *key = S_CREATE(gkctx); \ | |
673 | key->k.ops = &gkops; \ | |
674 | pre##_eaxsetkey(&key->key, k, ksz); \ | |
675 | return (&key->k); \ | |
676 | } \ | |
677 | \ | |
678 | const gcaead pre##_eax = { \ | |
679 | name "-eax", \ | |
680 | pre##_keysz, pre##_eaxnoncesz, pre##_eaxtagsz, \ | |
681 | PRE##_BLKSZ, 0, 0, 0, \ | |
682 | gckey \ | |
683 | }; \ | |
684 | \ | |
685 | EAX_TESTX(PRE, pre, name, fname) | |
686 | ||
687 | /*----- Test rig ----------------------------------------------------------*/ | |
688 | ||
689 | #define EAX_TEST(PRE, pre) EAX_TESTX(PRE, pre, #pre, #pre) | |
690 | ||
691 | /* --- @EAX_TEST@ --- * | |
692 | * | |
693 | * Arguments: @PRE, pre@ = prefixes for the underlying block cipher | |
694 | * | |
695 | * Use: Standard test rig for EAX functions. | |
696 | */ | |
697 | ||
698 | #ifdef TEST_RIG | |
699 | ||
700 | #include <stdio.h> | |
701 | ||
702 | #include <mLib/dstr.h> | |
141c1284 | 703 | #include <mLib/macros.h> |
2964c388 MW |
704 | #include <mLib/quis.h> |
705 | #include <mLib/testrig.h> | |
706 | ||
707 | #define EAX_TESTX(PRE, pre, name, fname) \ | |
708 | \ | |
709 | static int eaxverify(dstr *v) \ | |
710 | { \ | |
711 | pre##_eaxkey key; \ | |
712 | pre##_eaxaadctx aad; \ | |
713 | pre##_eaxctx ctx; \ | |
714 | int ok = 1, win; \ | |
715 | int i; \ | |
716 | octet *p; \ | |
717 | int szs[] = { 1, 7, 192, -1, 0 }, *ip; \ | |
718 | size_t hsz, msz; \ | |
719 | dstr d = DSTR_INIT, t = DSTR_INIT; \ | |
720 | buf b; \ | |
721 | \ | |
722 | dstr_ensure(&d, v[4].len > v[3].len ? v[4].len : v[3].len); \ | |
723 | dstr_ensure(&t, v[5].len); t.len = v[5].len; \ | |
724 | \ | |
725 | pre##_eaxsetkey(&key, v[0].buf, v[0].len); \ | |
726 | \ | |
727 | for (ip = szs; *ip; ip++) { \ | |
728 | \ | |
729 | pre##_eaxinit(&ctx, &key, (octet *)v[1].buf, v[1].len); \ | |
730 | \ | |
731 | i = *ip; \ | |
732 | hsz = v[2].len; \ | |
733 | if (i == -1) i = hsz; \ | |
734 | if (i > hsz) continue; \ | |
735 | p = (octet *)v[2].buf; \ | |
736 | pre##_eaxaadinit(&aad, &key); \ | |
737 | while (hsz) { \ | |
738 | if (i > hsz) i = hsz; \ | |
739 | pre##_eaxaadhash(&aad, p, i); \ | |
740 | p += i; hsz -= i; \ | |
741 | } \ | |
742 | \ | |
743 | buf_init(&b, d.buf, d.sz); \ | |
744 | i = *ip; \ | |
745 | msz = v[3].len; \ | |
746 | if (i == -1) i = msz; \ | |
747 | if (i > msz) continue; \ | |
748 | p = (octet *)v[3].buf; \ | |
749 | while (msz) { \ | |
750 | if (i > msz) i = msz; \ | |
751 | if (pre##_eaxencrypt(&ctx, p, i, &b)) { \ | |
752 | puts("!! eaxencrypt reports failure"); \ | |
753 | goto fail_enc; \ | |
754 | } \ | |
755 | p += i; msz -= i; \ | |
756 | } \ | |
757 | \ | |
758 | if (pre##_eaxencryptdone(&ctx, &aad, &b, (octet *)t.buf, t.len)) { \ | |
759 | puts("!! eaxencryptdone reports failure"); \ | |
760 | goto fail_enc; \ | |
761 | } \ | |
762 | d.len = BLEN(&b); \ | |
763 | \ | |
764 | if (d.len != v[4].len || \ | |
141c1284 MW |
765 | MEMCMP(d.buf, !=, v[4].buf, v[4].len) || \ |
766 | MEMCMP(t.buf, !=, v[5].buf, v[5].len)) { \ | |
2964c388 MW |
767 | fail_enc: \ |
768 | printf("\nfail encrypt:\n\tstep = %i", *ip); \ | |
769 | fputs("\n\tkey = ", stdout); type_hex.dump(&v[0], stdout); \ | |
770 | fputs("\n\tnonce = ", stdout); type_hex.dump(&v[1], stdout); \ | |
771 | fputs("\n\theader = ", stdout); type_hex.dump(&v[2], stdout); \ | |
772 | fputs("\n\tmessage = ", stdout); type_hex.dump(&v[3], stdout); \ | |
773 | fputs("\n\texp ct = ", stdout); type_hex.dump(&v[4], stdout); \ | |
774 | fputs("\n\tcalc ct = ", stdout); type_hex.dump(&d, stdout); \ | |
775 | fputs("\n\texp tag = ", stdout); type_hex.dump(&v[5], stdout); \ | |
776 | fputs("\n\tcalc tag = ", stdout); type_hex.dump(&t, stdout); \ | |
777 | putchar('\n'); \ | |
778 | ok = 0; \ | |
779 | } \ | |
780 | \ | |
781 | pre##_eaxinit(&ctx, &key, (octet *)v[1].buf, v[1].len); \ | |
782 | \ | |
783 | buf_init(&b, d.buf, d.sz); \ | |
784 | i = *ip; \ | |
785 | msz = v[4].len; \ | |
786 | if (i == -1) i = msz; \ | |
787 | if (i > msz) continue; \ | |
788 | p = (octet *)v[4].buf; \ | |
789 | while (msz) { \ | |
790 | if (i > msz) i = msz; \ | |
791 | if (pre##_eaxdecrypt(&ctx, p, i, &b)) { \ | |
792 | puts("!! eaxdecrypt reports failure"); \ | |
793 | win = 0; goto fail_dec; \ | |
794 | } \ | |
795 | p += i; msz -= i; \ | |
796 | } \ | |
797 | \ | |
798 | win = pre##_eaxdecryptdone(&ctx, &aad, &b, \ | |
799 | (octet *)v[5].buf, v[5].len); \ | |
800 | if (win < 0) { \ | |
801 | puts("!! eaxdecryptdone reports failure"); \ | |
802 | goto fail_dec; \ | |
803 | } \ | |
804 | d.len = BLEN(&b); \ | |
805 | \ | |
806 | if (d.len != v[3].len || !win || \ | |
141c1284 | 807 | MEMCMP(d.buf, !=, v[3].buf, v[3].len)) { \ |
2964c388 MW |
808 | fail_dec: \ |
809 | printf("\nfail decrypt:\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\tciphertext = ", stdout); type_hex.dump(&v[4], stdout); \ | |
814 | fputs("\n\texp pt = ", stdout); type_hex.dump(&v[3], stdout); \ | |
815 | fputs("\n\tcalc pt = ", stdout); type_hex.dump(&d, stdout); \ | |
816 | fputs("\n\ttag = ", stdout); type_hex.dump(&v[5], stdout); \ | |
817 | printf("\n\tverify %s", win ? "ok" : "FAILED"); \ | |
818 | putchar('\n'); \ | |
819 | ok = 0; \ | |
820 | } \ | |
821 | } \ | |
822 | \ | |
823 | dstr_destroy(&d); dstr_destroy(&t); \ | |
824 | return (ok); \ | |
825 | } \ | |
826 | \ | |
827 | static test_chunk aeaddefs[] = { \ | |
828 | { name "-eax", eaxverify, \ | |
829 | { &type_hex, &type_hex, &type_hex, &type_hex, \ | |
830 | &type_hex, &type_hex, 0 } }, \ | |
831 | { 0, 0, { 0 } } \ | |
832 | }; \ | |
833 | \ | |
834 | int main(int argc, char *argv[]) \ | |
835 | { \ | |
836 | ego(argv[0]); \ | |
837 | test_run(argc, argv, aeaddefs, SRCDIR"/t/" fname); \ | |
838 | return (0); \ | |
839 | } | |
840 | ||
841 | #else | |
842 | # define EAX_TESTX(PRE, pre, name, fname) | |
843 | #endif | |
844 | ||
845 | /*----- That's all, folks -------------------------------------------------*/ | |
846 | ||
847 | #ifdef __cplusplus | |
848 | } | |
849 | #endif | |
850 | ||
851 | #endif |