blob: e41f3d2ed9c321b0dcf70c373d5d967fc03c18f8
1 | /* |
2 | * ChaCha20-Poly1305 AEAD, RFC7539 |
3 | * |
4 | * Copyright (C) 2015 Martin Willi |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by |
8 | * the Free Software Foundation; either version 2 of the License, or |
9 | * (at your option) any later version. |
10 | */ |
11 | |
12 | #include <crypto/internal/aead.h> |
13 | #include <crypto/internal/hash.h> |
14 | #include <crypto/internal/skcipher.h> |
15 | #include <crypto/scatterwalk.h> |
16 | #include <crypto/chacha.h> |
17 | #include <crypto/poly1305.h> |
18 | #include <linux/err.h> |
19 | #include <linux/init.h> |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> |
22 | |
23 | #include "internal.h" |
24 | |
25 | #define CHACHAPOLY_IV_SIZE 12 |
26 | |
27 | struct chachapoly_instance_ctx { |
28 | struct crypto_skcipher_spawn chacha; |
29 | struct crypto_ahash_spawn poly; |
30 | unsigned int saltlen; |
31 | }; |
32 | |
33 | struct chachapoly_ctx { |
34 | struct crypto_skcipher *chacha; |
35 | struct crypto_ahash *poly; |
36 | /* key bytes we use for the ChaCha20 IV */ |
37 | unsigned int saltlen; |
38 | u8 salt[]; |
39 | }; |
40 | |
41 | struct poly_req { |
42 | /* zero byte padding for AD/ciphertext, as needed */ |
43 | u8 pad[POLY1305_BLOCK_SIZE]; |
44 | /* tail data with AD/ciphertext lengths */ |
45 | struct { |
46 | __le64 assoclen; |
47 | __le64 cryptlen; |
48 | } tail; |
49 | struct scatterlist src[1]; |
50 | struct ahash_request req; /* must be last member */ |
51 | }; |
52 | |
53 | struct chacha_req { |
54 | u8 iv[CHACHA_IV_SIZE]; |
55 | struct scatterlist src[1]; |
56 | struct skcipher_request req; /* must be last member */ |
57 | }; |
58 | |
59 | struct chachapoly_req_ctx { |
60 | struct scatterlist src[2]; |
61 | struct scatterlist dst[2]; |
62 | /* the key we generate for Poly1305 using Chacha20 */ |
63 | u8 key[POLY1305_KEY_SIZE]; |
64 | /* calculated Poly1305 tag */ |
65 | u8 tag[POLY1305_DIGEST_SIZE]; |
66 | /* length of data to en/decrypt, without ICV */ |
67 | unsigned int cryptlen; |
68 | /* Actual AD, excluding IV */ |
69 | unsigned int assoclen; |
70 | union { |
71 | struct poly_req poly; |
72 | struct chacha_req chacha; |
73 | } u; |
74 | }; |
75 | |
76 | static inline void async_done_continue(struct aead_request *req, int err, |
77 | int (*cont)(struct aead_request *)) |
78 | { |
79 | if (!err) |
80 | err = cont(req); |
81 | |
82 | if (err != -EINPROGRESS && err != -EBUSY) |
83 | aead_request_complete(req, err); |
84 | } |
85 | |
86 | static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb) |
87 | { |
88 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
89 | __le32 leicb = cpu_to_le32(icb); |
90 | |
91 | memcpy(iv, &leicb, sizeof(leicb)); |
92 | memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen); |
93 | memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv, |
94 | CHACHA_IV_SIZE - sizeof(leicb) - ctx->saltlen); |
95 | } |
96 | |
97 | static int poly_verify_tag(struct aead_request *req) |
98 | { |
99 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
100 | u8 tag[sizeof(rctx->tag)]; |
101 | |
102 | scatterwalk_map_and_copy(tag, req->src, |
103 | req->assoclen + rctx->cryptlen, |
104 | sizeof(tag), 0); |
105 | if (crypto_memneq(tag, rctx->tag, sizeof(tag))) |
106 | return -EBADMSG; |
107 | return 0; |
108 | } |
109 | |
110 | static int poly_copy_tag(struct aead_request *req) |
111 | { |
112 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
113 | |
114 | scatterwalk_map_and_copy(rctx->tag, req->dst, |
115 | req->assoclen + rctx->cryptlen, |
116 | sizeof(rctx->tag), 1); |
117 | return 0; |
118 | } |
119 | |
120 | static void chacha_decrypt_done(struct crypto_async_request *areq, int err) |
121 | { |
122 | async_done_continue(areq->data, err, poly_verify_tag); |
123 | } |
124 | |
125 | static int chacha_decrypt(struct aead_request *req) |
126 | { |
127 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
128 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
129 | struct chacha_req *creq = &rctx->u.chacha; |
130 | struct scatterlist *src, *dst; |
131 | int err; |
132 | |
133 | if (rctx->cryptlen == 0) |
134 | goto skip; |
135 | |
136 | chacha_iv(creq->iv, req, 1); |
137 | |
138 | sg_init_table(rctx->src, 2); |
139 | src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); |
140 | dst = src; |
141 | |
142 | if (req->src != req->dst) { |
143 | sg_init_table(rctx->dst, 2); |
144 | dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); |
145 | } |
146 | |
147 | skcipher_request_set_callback(&creq->req, aead_request_flags(req), |
148 | chacha_decrypt_done, req); |
149 | skcipher_request_set_tfm(&creq->req, ctx->chacha); |
150 | skcipher_request_set_crypt(&creq->req, src, dst, |
151 | rctx->cryptlen, creq->iv); |
152 | err = crypto_skcipher_decrypt(&creq->req); |
153 | if (err) |
154 | return err; |
155 | |
156 | skip: |
157 | return poly_verify_tag(req); |
158 | } |
159 | |
160 | static int poly_tail_continue(struct aead_request *req) |
161 | { |
162 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
163 | |
164 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ |
165 | return poly_copy_tag(req); |
166 | |
167 | return chacha_decrypt(req); |
168 | } |
169 | |
170 | static void poly_tail_done(struct crypto_async_request *areq, int err) |
171 | { |
172 | async_done_continue(areq->data, err, poly_tail_continue); |
173 | } |
174 | |
175 | static int poly_tail(struct aead_request *req) |
176 | { |
177 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); |
178 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
179 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
180 | struct poly_req *preq = &rctx->u.poly; |
181 | __le64 len; |
182 | int err; |
183 | |
184 | sg_init_table(preq->src, 1); |
185 | len = cpu_to_le64(rctx->assoclen); |
186 | memcpy(&preq->tail.assoclen, &len, sizeof(len)); |
187 | len = cpu_to_le64(rctx->cryptlen); |
188 | memcpy(&preq->tail.cryptlen, &len, sizeof(len)); |
189 | sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail)); |
190 | |
191 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
192 | poly_tail_done, req); |
193 | ahash_request_set_tfm(&preq->req, ctx->poly); |
194 | ahash_request_set_crypt(&preq->req, preq->src, |
195 | rctx->tag, sizeof(preq->tail)); |
196 | |
197 | err = crypto_ahash_finup(&preq->req); |
198 | if (err) |
199 | return err; |
200 | |
201 | return poly_tail_continue(req); |
202 | } |
203 | |
204 | static void poly_cipherpad_done(struct crypto_async_request *areq, int err) |
205 | { |
206 | async_done_continue(areq->data, err, poly_tail); |
207 | } |
208 | |
209 | static int poly_cipherpad(struct aead_request *req) |
210 | { |
211 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
212 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
213 | struct poly_req *preq = &rctx->u.poly; |
214 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; |
215 | int err; |
216 | |
217 | padlen = (bs - (rctx->cryptlen % bs)) % bs; |
218 | memset(preq->pad, 0, sizeof(preq->pad)); |
219 | sg_init_table(preq->src, 1); |
220 | sg_set_buf(preq->src, &preq->pad, padlen); |
221 | |
222 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
223 | poly_cipherpad_done, req); |
224 | ahash_request_set_tfm(&preq->req, ctx->poly); |
225 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); |
226 | |
227 | err = crypto_ahash_update(&preq->req); |
228 | if (err) |
229 | return err; |
230 | |
231 | return poly_tail(req); |
232 | } |
233 | |
234 | static void poly_cipher_done(struct crypto_async_request *areq, int err) |
235 | { |
236 | async_done_continue(areq->data, err, poly_cipherpad); |
237 | } |
238 | |
239 | static int poly_cipher(struct aead_request *req) |
240 | { |
241 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
242 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
243 | struct poly_req *preq = &rctx->u.poly; |
244 | struct scatterlist *crypt = req->src; |
245 | int err; |
246 | |
247 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ |
248 | crypt = req->dst; |
249 | |
250 | sg_init_table(rctx->src, 2); |
251 | crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen); |
252 | |
253 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
254 | poly_cipher_done, req); |
255 | ahash_request_set_tfm(&preq->req, ctx->poly); |
256 | ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen); |
257 | |
258 | err = crypto_ahash_update(&preq->req); |
259 | if (err) |
260 | return err; |
261 | |
262 | return poly_cipherpad(req); |
263 | } |
264 | |
265 | static void poly_adpad_done(struct crypto_async_request *areq, int err) |
266 | { |
267 | async_done_continue(areq->data, err, poly_cipher); |
268 | } |
269 | |
270 | static int poly_adpad(struct aead_request *req) |
271 | { |
272 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
273 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
274 | struct poly_req *preq = &rctx->u.poly; |
275 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; |
276 | int err; |
277 | |
278 | padlen = (bs - (rctx->assoclen % bs)) % bs; |
279 | memset(preq->pad, 0, sizeof(preq->pad)); |
280 | sg_init_table(preq->src, 1); |
281 | sg_set_buf(preq->src, preq->pad, padlen); |
282 | |
283 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
284 | poly_adpad_done, req); |
285 | ahash_request_set_tfm(&preq->req, ctx->poly); |
286 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); |
287 | |
288 | err = crypto_ahash_update(&preq->req); |
289 | if (err) |
290 | return err; |
291 | |
292 | return poly_cipher(req); |
293 | } |
294 | |
295 | static void poly_ad_done(struct crypto_async_request *areq, int err) |
296 | { |
297 | async_done_continue(areq->data, err, poly_adpad); |
298 | } |
299 | |
300 | static int poly_ad(struct aead_request *req) |
301 | { |
302 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
303 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
304 | struct poly_req *preq = &rctx->u.poly; |
305 | int err; |
306 | |
307 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
308 | poly_ad_done, req); |
309 | ahash_request_set_tfm(&preq->req, ctx->poly); |
310 | ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen); |
311 | |
312 | err = crypto_ahash_update(&preq->req); |
313 | if (err) |
314 | return err; |
315 | |
316 | return poly_adpad(req); |
317 | } |
318 | |
319 | static void poly_setkey_done(struct crypto_async_request *areq, int err) |
320 | { |
321 | async_done_continue(areq->data, err, poly_ad); |
322 | } |
323 | |
324 | static int poly_setkey(struct aead_request *req) |
325 | { |
326 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
327 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
328 | struct poly_req *preq = &rctx->u.poly; |
329 | int err; |
330 | |
331 | sg_init_table(preq->src, 1); |
332 | sg_set_buf(preq->src, rctx->key, sizeof(rctx->key)); |
333 | |
334 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
335 | poly_setkey_done, req); |
336 | ahash_request_set_tfm(&preq->req, ctx->poly); |
337 | ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key)); |
338 | |
339 | err = crypto_ahash_update(&preq->req); |
340 | if (err) |
341 | return err; |
342 | |
343 | return poly_ad(req); |
344 | } |
345 | |
346 | static void poly_init_done(struct crypto_async_request *areq, int err) |
347 | { |
348 | async_done_continue(areq->data, err, poly_setkey); |
349 | } |
350 | |
351 | static int poly_init(struct aead_request *req) |
352 | { |
353 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
354 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
355 | struct poly_req *preq = &rctx->u.poly; |
356 | int err; |
357 | |
358 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
359 | poly_init_done, req); |
360 | ahash_request_set_tfm(&preq->req, ctx->poly); |
361 | |
362 | err = crypto_ahash_init(&preq->req); |
363 | if (err) |
364 | return err; |
365 | |
366 | return poly_setkey(req); |
367 | } |
368 | |
369 | static void poly_genkey_done(struct crypto_async_request *areq, int err) |
370 | { |
371 | async_done_continue(areq->data, err, poly_init); |
372 | } |
373 | |
374 | static int poly_genkey(struct aead_request *req) |
375 | { |
376 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); |
377 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
378 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
379 | struct chacha_req *creq = &rctx->u.chacha; |
380 | int err; |
381 | |
382 | rctx->assoclen = req->assoclen; |
383 | |
384 | if (crypto_aead_ivsize(tfm) == 8) { |
385 | if (rctx->assoclen < 8) |
386 | return -EINVAL; |
387 | rctx->assoclen -= 8; |
388 | } |
389 | |
390 | sg_init_table(creq->src, 1); |
391 | memset(rctx->key, 0, sizeof(rctx->key)); |
392 | sg_set_buf(creq->src, rctx->key, sizeof(rctx->key)); |
393 | |
394 | chacha_iv(creq->iv, req, 0); |
395 | |
396 | skcipher_request_set_callback(&creq->req, aead_request_flags(req), |
397 | poly_genkey_done, req); |
398 | skcipher_request_set_tfm(&creq->req, ctx->chacha); |
399 | skcipher_request_set_crypt(&creq->req, creq->src, creq->src, |
400 | POLY1305_KEY_SIZE, creq->iv); |
401 | |
402 | err = crypto_skcipher_decrypt(&creq->req); |
403 | if (err) |
404 | return err; |
405 | |
406 | return poly_init(req); |
407 | } |
408 | |
409 | static void chacha_encrypt_done(struct crypto_async_request *areq, int err) |
410 | { |
411 | async_done_continue(areq->data, err, poly_genkey); |
412 | } |
413 | |
414 | static int chacha_encrypt(struct aead_request *req) |
415 | { |
416 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); |
417 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
418 | struct chacha_req *creq = &rctx->u.chacha; |
419 | struct scatterlist *src, *dst; |
420 | int err; |
421 | |
422 | if (req->cryptlen == 0) |
423 | goto skip; |
424 | |
425 | chacha_iv(creq->iv, req, 1); |
426 | |
427 | sg_init_table(rctx->src, 2); |
428 | src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); |
429 | dst = src; |
430 | |
431 | if (req->src != req->dst) { |
432 | sg_init_table(rctx->dst, 2); |
433 | dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); |
434 | } |
435 | |
436 | skcipher_request_set_callback(&creq->req, aead_request_flags(req), |
437 | chacha_encrypt_done, req); |
438 | skcipher_request_set_tfm(&creq->req, ctx->chacha); |
439 | skcipher_request_set_crypt(&creq->req, src, dst, |
440 | req->cryptlen, creq->iv); |
441 | err = crypto_skcipher_encrypt(&creq->req); |
442 | if (err) |
443 | return err; |
444 | |
445 | skip: |
446 | return poly_genkey(req); |
447 | } |
448 | |
449 | static int chachapoly_encrypt(struct aead_request *req) |
450 | { |
451 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
452 | |
453 | rctx->cryptlen = req->cryptlen; |
454 | |
455 | /* encrypt call chain: |
456 | * - chacha_encrypt/done() |
457 | * - poly_genkey/done() |
458 | * - poly_init/done() |
459 | * - poly_setkey/done() |
460 | * - poly_ad/done() |
461 | * - poly_adpad/done() |
462 | * - poly_cipher/done() |
463 | * - poly_cipherpad/done() |
464 | * - poly_tail/done/continue() |
465 | * - poly_copy_tag() |
466 | */ |
467 | return chacha_encrypt(req); |
468 | } |
469 | |
470 | static int chachapoly_decrypt(struct aead_request *req) |
471 | { |
472 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
473 | |
474 | rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; |
475 | |
476 | /* decrypt call chain: |
477 | * - poly_genkey/done() |
478 | * - poly_init/done() |
479 | * - poly_setkey/done() |
480 | * - poly_ad/done() |
481 | * - poly_adpad/done() |
482 | * - poly_cipher/done() |
483 | * - poly_cipherpad/done() |
484 | * - poly_tail/done/continue() |
485 | * - chacha_decrypt/done() |
486 | * - poly_verify_tag() |
487 | */ |
488 | return poly_genkey(req); |
489 | } |
490 | |
491 | static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key, |
492 | unsigned int keylen) |
493 | { |
494 | struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); |
495 | int err; |
496 | |
497 | if (keylen != ctx->saltlen + CHACHA_KEY_SIZE) |
498 | return -EINVAL; |
499 | |
500 | keylen -= ctx->saltlen; |
501 | memcpy(ctx->salt, key + keylen, ctx->saltlen); |
502 | |
503 | crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK); |
504 | crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) & |
505 | CRYPTO_TFM_REQ_MASK); |
506 | |
507 | err = crypto_skcipher_setkey(ctx->chacha, key, keylen); |
508 | crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctx->chacha) & |
509 | CRYPTO_TFM_RES_MASK); |
510 | return err; |
511 | } |
512 | |
513 | static int chachapoly_setauthsize(struct crypto_aead *tfm, |
514 | unsigned int authsize) |
515 | { |
516 | if (authsize != POLY1305_DIGEST_SIZE) |
517 | return -EINVAL; |
518 | |
519 | return 0; |
520 | } |
521 | |
522 | static int chachapoly_init(struct crypto_aead *tfm) |
523 | { |
524 | struct aead_instance *inst = aead_alg_instance(tfm); |
525 | struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst); |
526 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
527 | struct crypto_skcipher *chacha; |
528 | struct crypto_ahash *poly; |
529 | unsigned long align; |
530 | |
531 | poly = crypto_spawn_ahash(&ictx->poly); |
532 | if (IS_ERR(poly)) |
533 | return PTR_ERR(poly); |
534 | |
535 | chacha = crypto_spawn_skcipher2(&ictx->chacha); |
536 | if (IS_ERR(chacha)) { |
537 | crypto_free_ahash(poly); |
538 | return PTR_ERR(chacha); |
539 | } |
540 | |
541 | ctx->chacha = chacha; |
542 | ctx->poly = poly; |
543 | ctx->saltlen = ictx->saltlen; |
544 | |
545 | align = crypto_aead_alignmask(tfm); |
546 | align &= ~(crypto_tfm_ctx_alignment() - 1); |
547 | crypto_aead_set_reqsize( |
548 | tfm, |
549 | align + offsetof(struct chachapoly_req_ctx, u) + |
550 | max(offsetof(struct chacha_req, req) + |
551 | sizeof(struct skcipher_request) + |
552 | crypto_skcipher_reqsize(chacha), |
553 | offsetof(struct poly_req, req) + |
554 | sizeof(struct ahash_request) + |
555 | crypto_ahash_reqsize(poly))); |
556 | |
557 | return 0; |
558 | } |
559 | |
560 | static void chachapoly_exit(struct crypto_aead *tfm) |
561 | { |
562 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
563 | |
564 | crypto_free_ahash(ctx->poly); |
565 | crypto_free_skcipher(ctx->chacha); |
566 | } |
567 | |
568 | static void chachapoly_free(struct aead_instance *inst) |
569 | { |
570 | struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst); |
571 | |
572 | crypto_drop_skcipher(&ctx->chacha); |
573 | crypto_drop_ahash(&ctx->poly); |
574 | kfree(inst); |
575 | } |
576 | |
577 | static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb, |
578 | const char *name, unsigned int ivsize) |
579 | { |
580 | struct crypto_attr_type *algt; |
581 | struct aead_instance *inst; |
582 | struct skcipher_alg *chacha; |
583 | struct crypto_alg *poly; |
584 | struct hash_alg_common *poly_hash; |
585 | struct chachapoly_instance_ctx *ctx; |
586 | const char *chacha_name, *poly_name; |
587 | int err; |
588 | |
589 | if (ivsize > CHACHAPOLY_IV_SIZE) |
590 | return -EINVAL; |
591 | |
592 | algt = crypto_get_attr_type(tb); |
593 | if (IS_ERR(algt)) |
594 | return PTR_ERR(algt); |
595 | |
596 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) |
597 | return -EINVAL; |
598 | |
599 | chacha_name = crypto_attr_alg_name(tb[1]); |
600 | if (IS_ERR(chacha_name)) |
601 | return PTR_ERR(chacha_name); |
602 | poly_name = crypto_attr_alg_name(tb[2]); |
603 | if (IS_ERR(poly_name)) |
604 | return PTR_ERR(poly_name); |
605 | |
606 | poly = crypto_find_alg(poly_name, &crypto_ahash_type, |
607 | CRYPTO_ALG_TYPE_HASH, |
608 | CRYPTO_ALG_TYPE_AHASH_MASK | |
609 | crypto_requires_sync(algt->type, |
610 | algt->mask)); |
611 | if (IS_ERR(poly)) |
612 | return PTR_ERR(poly); |
613 | poly_hash = __crypto_hash_alg_common(poly); |
614 | |
615 | err = -EINVAL; |
616 | if (poly_hash->digestsize != POLY1305_DIGEST_SIZE) |
617 | goto out_put_poly; |
618 | |
619 | err = -ENOMEM; |
620 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); |
621 | if (!inst) |
622 | goto out_put_poly; |
623 | |
624 | ctx = aead_instance_ctx(inst); |
625 | ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; |
626 | err = crypto_init_ahash_spawn(&ctx->poly, poly_hash, |
627 | aead_crypto_instance(inst)); |
628 | if (err) |
629 | goto err_free_inst; |
630 | |
631 | crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst)); |
632 | err = crypto_grab_skcipher2(&ctx->chacha, chacha_name, 0, |
633 | crypto_requires_sync(algt->type, |
634 | algt->mask)); |
635 | if (err) |
636 | goto err_drop_poly; |
637 | |
638 | chacha = crypto_spawn_skcipher_alg(&ctx->chacha); |
639 | |
640 | err = -EINVAL; |
641 | /* Need 16-byte IV size, including Initial Block Counter value */ |
642 | if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE) |
643 | goto out_drop_chacha; |
644 | /* Not a stream cipher? */ |
645 | if (chacha->base.cra_blocksize != 1) |
646 | goto out_drop_chacha; |
647 | |
648 | err = -ENAMETOOLONG; |
649 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
650 | "%s(%s,%s)", name, chacha->base.cra_name, |
651 | poly->cra_name) >= CRYPTO_MAX_ALG_NAME) |
652 | goto out_drop_chacha; |
653 | if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, |
654 | "%s(%s,%s)", name, chacha->base.cra_driver_name, |
655 | poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) |
656 | goto out_drop_chacha; |
657 | |
658 | inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) & |
659 | CRYPTO_ALG_ASYNC; |
660 | inst->alg.base.cra_priority = (chacha->base.cra_priority + |
661 | poly->cra_priority) / 2; |
662 | inst->alg.base.cra_blocksize = 1; |
663 | inst->alg.base.cra_alignmask = chacha->base.cra_alignmask | |
664 | poly->cra_alignmask; |
665 | inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) + |
666 | ctx->saltlen; |
667 | inst->alg.ivsize = ivsize; |
668 | inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha); |
669 | inst->alg.maxauthsize = POLY1305_DIGEST_SIZE; |
670 | inst->alg.init = chachapoly_init; |
671 | inst->alg.exit = chachapoly_exit; |
672 | inst->alg.encrypt = chachapoly_encrypt; |
673 | inst->alg.decrypt = chachapoly_decrypt; |
674 | inst->alg.setkey = chachapoly_setkey; |
675 | inst->alg.setauthsize = chachapoly_setauthsize; |
676 | |
677 | inst->free = chachapoly_free; |
678 | |
679 | err = aead_register_instance(tmpl, inst); |
680 | if (err) |
681 | goto out_drop_chacha; |
682 | |
683 | out_put_poly: |
684 | crypto_mod_put(poly); |
685 | return err; |
686 | |
687 | out_drop_chacha: |
688 | crypto_drop_skcipher(&ctx->chacha); |
689 | err_drop_poly: |
690 | crypto_drop_ahash(&ctx->poly); |
691 | err_free_inst: |
692 | kfree(inst); |
693 | goto out_put_poly; |
694 | } |
695 | |
696 | static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb) |
697 | { |
698 | return chachapoly_create(tmpl, tb, "rfc7539", 12); |
699 | } |
700 | |
701 | static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb) |
702 | { |
703 | return chachapoly_create(tmpl, tb, "rfc7539esp", 8); |
704 | } |
705 | |
706 | static struct crypto_template rfc7539_tmpl = { |
707 | .name = "rfc7539", |
708 | .create = rfc7539_create, |
709 | .module = THIS_MODULE, |
710 | }; |
711 | |
712 | static struct crypto_template rfc7539esp_tmpl = { |
713 | .name = "rfc7539esp", |
714 | .create = rfc7539esp_create, |
715 | .module = THIS_MODULE, |
716 | }; |
717 | |
718 | static int __init chacha20poly1305_module_init(void) |
719 | { |
720 | int err; |
721 | |
722 | err = crypto_register_template(&rfc7539_tmpl); |
723 | if (err) |
724 | return err; |
725 | |
726 | err = crypto_register_template(&rfc7539esp_tmpl); |
727 | if (err) |
728 | crypto_unregister_template(&rfc7539_tmpl); |
729 | |
730 | return err; |
731 | } |
732 | |
733 | static void __exit chacha20poly1305_module_exit(void) |
734 | { |
735 | crypto_unregister_template(&rfc7539esp_tmpl); |
736 | crypto_unregister_template(&rfc7539_tmpl); |
737 | } |
738 | |
739 | module_init(chacha20poly1305_module_init); |
740 | module_exit(chacha20poly1305_module_exit); |
741 | |
742 | MODULE_LICENSE("GPL"); |
743 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); |
744 | MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); |
745 | MODULE_ALIAS_CRYPTO("rfc7539"); |
746 | MODULE_ALIAS_CRYPTO("rfc7539esp"); |
747 |