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71ebc4d1 MW |
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 <linux/err.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/module.h> | |
20 | ||
21 | #include "internal.h" | |
22 | ||
23 | #define POLY1305_BLOCK_SIZE 16 | |
24 | #define POLY1305_DIGEST_SIZE 16 | |
25 | #define POLY1305_KEY_SIZE 32 | |
26 | #define CHACHA20_KEY_SIZE 32 | |
27 | #define CHACHA20_IV_SIZE 16 | |
28 | #define CHACHAPOLY_IV_SIZE 12 | |
29 | ||
30 | struct chachapoly_instance_ctx { | |
31 | struct crypto_skcipher_spawn chacha; | |
32 | struct crypto_ahash_spawn poly; | |
33 | unsigned int saltlen; | |
34 | }; | |
35 | ||
36 | struct chachapoly_ctx { | |
37 | struct crypto_ablkcipher *chacha; | |
38 | struct crypto_ahash *poly; | |
39 | /* key bytes we use for the ChaCha20 IV */ | |
40 | unsigned int saltlen; | |
41 | u8 salt[]; | |
42 | }; | |
43 | ||
44 | struct poly_req { | |
45 | /* zero byte padding for AD/ciphertext, as needed */ | |
46 | u8 pad[POLY1305_BLOCK_SIZE]; | |
47 | /* tail data with AD/ciphertext lengths */ | |
48 | struct { | |
49 | __le64 assoclen; | |
50 | __le64 cryptlen; | |
51 | } tail; | |
52 | struct scatterlist src[1]; | |
53 | struct ahash_request req; /* must be last member */ | |
54 | }; | |
55 | ||
56 | struct chacha_req { | |
57 | /* the key we generate for Poly1305 using Chacha20 */ | |
58 | u8 key[POLY1305_KEY_SIZE]; | |
59 | u8 iv[CHACHA20_IV_SIZE]; | |
60 | struct scatterlist src[1]; | |
61 | struct ablkcipher_request req; /* must be last member */ | |
62 | }; | |
63 | ||
64 | struct chachapoly_req_ctx { | |
65 | /* calculated Poly1305 tag */ | |
66 | u8 tag[POLY1305_DIGEST_SIZE]; | |
67 | /* length of data to en/decrypt, without ICV */ | |
68 | unsigned int cryptlen; | |
69 | union { | |
70 | struct poly_req poly; | |
71 | struct chacha_req chacha; | |
72 | } u; | |
73 | }; | |
74 | ||
75 | static inline void async_done_continue(struct aead_request *req, int err, | |
76 | int (*cont)(struct aead_request *)) | |
77 | { | |
78 | if (!err) | |
79 | err = cont(req); | |
80 | ||
81 | if (err != -EINPROGRESS && err != -EBUSY) | |
82 | aead_request_complete(req, err); | |
83 | } | |
84 | ||
85 | static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb) | |
86 | { | |
87 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
88 | __le32 leicb = cpu_to_le32(icb); | |
89 | ||
90 | memcpy(iv, &leicb, sizeof(leicb)); | |
91 | memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen); | |
92 | memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv, | |
93 | CHACHA20_IV_SIZE - sizeof(leicb) - ctx->saltlen); | |
94 | } | |
95 | ||
96 | static int poly_verify_tag(struct aead_request *req) | |
97 | { | |
98 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
99 | u8 tag[sizeof(rctx->tag)]; | |
100 | ||
101 | scatterwalk_map_and_copy(tag, req->src, rctx->cryptlen, sizeof(tag), 0); | |
102 | if (crypto_memneq(tag, rctx->tag, sizeof(tag))) | |
103 | return -EBADMSG; | |
104 | return 0; | |
105 | } | |
106 | ||
107 | static int poly_copy_tag(struct aead_request *req) | |
108 | { | |
109 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
110 | ||
111 | scatterwalk_map_and_copy(rctx->tag, req->dst, rctx->cryptlen, | |
112 | sizeof(rctx->tag), 1); | |
113 | return 0; | |
114 | } | |
115 | ||
116 | static void chacha_decrypt_done(struct crypto_async_request *areq, int err) | |
117 | { | |
118 | async_done_continue(areq->data, err, poly_verify_tag); | |
119 | } | |
120 | ||
121 | static int chacha_decrypt(struct aead_request *req) | |
122 | { | |
123 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
124 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
125 | struct chacha_req *creq = &rctx->u.chacha; | |
126 | int err; | |
127 | ||
128 | chacha_iv(creq->iv, req, 1); | |
129 | ||
130 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), | |
131 | chacha_decrypt_done, req); | |
132 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); | |
133 | ablkcipher_request_set_crypt(&creq->req, req->src, req->dst, | |
134 | rctx->cryptlen, creq->iv); | |
135 | err = crypto_ablkcipher_decrypt(&creq->req); | |
136 | if (err) | |
137 | return err; | |
138 | ||
139 | return poly_verify_tag(req); | |
140 | } | |
141 | ||
142 | static int poly_tail_continue(struct aead_request *req) | |
143 | { | |
144 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
145 | ||
146 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ | |
147 | return poly_copy_tag(req); | |
148 | ||
149 | return chacha_decrypt(req); | |
150 | } | |
151 | ||
152 | static void poly_tail_done(struct crypto_async_request *areq, int err) | |
153 | { | |
154 | async_done_continue(areq->data, err, poly_tail_continue); | |
155 | } | |
156 | ||
157 | static int poly_tail(struct aead_request *req) | |
158 | { | |
159 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
160 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
161 | struct poly_req *preq = &rctx->u.poly; | |
162 | __le64 len; | |
163 | int err; | |
164 | ||
165 | sg_init_table(preq->src, 1); | |
166 | len = cpu_to_le64(req->assoclen); | |
167 | memcpy(&preq->tail.assoclen, &len, sizeof(len)); | |
168 | len = cpu_to_le64(rctx->cryptlen); | |
169 | memcpy(&preq->tail.cryptlen, &len, sizeof(len)); | |
170 | sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail)); | |
171 | ||
172 | ahash_request_set_callback(&preq->req, aead_request_flags(req), | |
173 | poly_tail_done, req); | |
174 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
175 | ahash_request_set_crypt(&preq->req, preq->src, | |
176 | rctx->tag, sizeof(preq->tail)); | |
177 | ||
178 | err = crypto_ahash_finup(&preq->req); | |
179 | if (err) | |
180 | return err; | |
181 | ||
182 | return poly_tail_continue(req); | |
183 | } | |
184 | ||
185 | static void poly_cipherpad_done(struct crypto_async_request *areq, int err) | |
186 | { | |
187 | async_done_continue(areq->data, err, poly_tail); | |
188 | } | |
189 | ||
190 | static int poly_cipherpad(struct aead_request *req) | |
191 | { | |
192 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
193 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
194 | struct poly_req *preq = &rctx->u.poly; | |
195 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; | |
196 | int err; | |
197 | ||
198 | padlen = (bs - (rctx->cryptlen % bs)) % bs; | |
199 | memset(preq->pad, 0, sizeof(preq->pad)); | |
200 | sg_init_table(preq->src, 1); | |
201 | sg_set_buf(preq->src, &preq->pad, padlen); | |
202 | ||
203 | ahash_request_set_callback(&preq->req, aead_request_flags(req), | |
204 | poly_cipherpad_done, req); | |
205 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
206 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); | |
207 | ||
208 | err = crypto_ahash_update(&preq->req); | |
209 | if (err) | |
210 | return err; | |
211 | ||
212 | return poly_tail(req); | |
213 | } | |
214 | ||
215 | static void poly_cipher_done(struct crypto_async_request *areq, int err) | |
216 | { | |
217 | async_done_continue(areq->data, err, poly_cipherpad); | |
218 | } | |
219 | ||
220 | static int poly_cipher(struct aead_request *req) | |
221 | { | |
222 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
223 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
224 | struct poly_req *preq = &rctx->u.poly; | |
225 | struct scatterlist *crypt = req->src; | |
226 | int err; | |
227 | ||
228 | if (rctx->cryptlen == req->cryptlen) /* encrypting */ | |
229 | crypt = req->dst; | |
230 | ||
231 | ahash_request_set_callback(&preq->req, aead_request_flags(req), | |
232 | poly_cipher_done, req); | |
233 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
234 | ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen); | |
235 | ||
236 | err = crypto_ahash_update(&preq->req); | |
237 | if (err) | |
238 | return err; | |
239 | ||
240 | return poly_cipherpad(req); | |
241 | } | |
242 | ||
243 | static void poly_adpad_done(struct crypto_async_request *areq, int err) | |
244 | { | |
245 | async_done_continue(areq->data, err, poly_cipher); | |
246 | } | |
247 | ||
248 | static int poly_adpad(struct aead_request *req) | |
249 | { | |
250 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
251 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
252 | struct poly_req *preq = &rctx->u.poly; | |
253 | unsigned int padlen, bs = POLY1305_BLOCK_SIZE; | |
254 | int err; | |
255 | ||
256 | padlen = (bs - (req->assoclen % bs)) % bs; | |
257 | memset(preq->pad, 0, sizeof(preq->pad)); | |
258 | sg_init_table(preq->src, 1); | |
259 | sg_set_buf(preq->src, preq->pad, padlen); | |
260 | ||
261 | ahash_request_set_callback(&preq->req, aead_request_flags(req), | |
262 | poly_adpad_done, req); | |
263 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
264 | ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen); | |
265 | ||
266 | err = crypto_ahash_update(&preq->req); | |
267 | if (err) | |
268 | return err; | |
269 | ||
270 | return poly_cipher(req); | |
271 | } | |
272 | ||
273 | static void poly_ad_done(struct crypto_async_request *areq, int err) | |
274 | { | |
275 | async_done_continue(areq->data, err, poly_adpad); | |
276 | } | |
277 | ||
278 | static int poly_ad(struct aead_request *req) | |
279 | { | |
280 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
281 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
282 | struct poly_req *preq = &rctx->u.poly; | |
283 | int err; | |
284 | ||
285 | ahash_request_set_callback(&preq->req, aead_request_flags(req), | |
286 | poly_ad_done, req); | |
287 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
288 | ahash_request_set_crypt(&preq->req, req->assoc, NULL, req->assoclen); | |
289 | ||
290 | err = crypto_ahash_update(&preq->req); | |
291 | if (err) | |
292 | return err; | |
293 | ||
294 | return poly_adpad(req); | |
295 | } | |
296 | ||
297 | static void poly_init_done(struct crypto_async_request *areq, int err) | |
298 | { | |
299 | async_done_continue(areq->data, err, poly_ad); | |
300 | } | |
301 | ||
302 | static int poly_init(struct aead_request *req) | |
303 | { | |
304 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
305 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
306 | struct poly_req *preq = &rctx->u.poly; | |
307 | int err; | |
308 | ||
309 | ahash_request_set_callback(&preq->req, aead_request_flags(req), | |
310 | poly_init_done, req); | |
311 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
312 | ||
313 | err = crypto_ahash_init(&preq->req); | |
314 | if (err) | |
315 | return err; | |
316 | ||
317 | return poly_ad(req); | |
318 | } | |
319 | ||
320 | static int poly_genkey_continue(struct aead_request *req) | |
321 | { | |
322 | struct crypto_aead *aead = crypto_aead_reqtfm(req); | |
323 | struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); | |
324 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
325 | struct chacha_req *creq = &rctx->u.chacha; | |
326 | int err; | |
327 | ||
328 | crypto_ahash_clear_flags(ctx->poly, CRYPTO_TFM_REQ_MASK); | |
329 | crypto_ahash_set_flags(ctx->poly, crypto_aead_get_flags(aead) & | |
330 | CRYPTO_TFM_REQ_MASK); | |
331 | ||
332 | err = crypto_ahash_setkey(ctx->poly, creq->key, sizeof(creq->key)); | |
333 | crypto_aead_set_flags(aead, crypto_ahash_get_flags(ctx->poly) & | |
334 | CRYPTO_TFM_RES_MASK); | |
335 | if (err) | |
336 | return err; | |
337 | ||
338 | return poly_init(req); | |
339 | } | |
340 | ||
341 | static void poly_genkey_done(struct crypto_async_request *areq, int err) | |
342 | { | |
343 | async_done_continue(areq->data, err, poly_genkey_continue); | |
344 | } | |
345 | ||
346 | static int poly_genkey(struct aead_request *req) | |
347 | { | |
348 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
349 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
350 | struct chacha_req *creq = &rctx->u.chacha; | |
351 | int err; | |
352 | ||
353 | sg_init_table(creq->src, 1); | |
354 | memset(creq->key, 0, sizeof(creq->key)); | |
355 | sg_set_buf(creq->src, creq->key, sizeof(creq->key)); | |
356 | ||
357 | chacha_iv(creq->iv, req, 0); | |
358 | ||
359 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), | |
360 | poly_genkey_done, req); | |
361 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); | |
362 | ablkcipher_request_set_crypt(&creq->req, creq->src, creq->src, | |
363 | POLY1305_KEY_SIZE, creq->iv); | |
364 | ||
365 | err = crypto_ablkcipher_decrypt(&creq->req); | |
366 | if (err) | |
367 | return err; | |
368 | ||
369 | return poly_genkey_continue(req); | |
370 | } | |
371 | ||
372 | static void chacha_encrypt_done(struct crypto_async_request *areq, int err) | |
373 | { | |
374 | async_done_continue(areq->data, err, poly_genkey); | |
375 | } | |
376 | ||
377 | static int chacha_encrypt(struct aead_request *req) | |
378 | { | |
379 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
380 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
381 | struct chacha_req *creq = &rctx->u.chacha; | |
382 | int err; | |
383 | ||
384 | chacha_iv(creq->iv, req, 1); | |
385 | ||
386 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), | |
387 | chacha_encrypt_done, req); | |
388 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); | |
389 | ablkcipher_request_set_crypt(&creq->req, req->src, req->dst, | |
390 | req->cryptlen, creq->iv); | |
391 | err = crypto_ablkcipher_encrypt(&creq->req); | |
392 | if (err) | |
393 | return err; | |
394 | ||
395 | return poly_genkey(req); | |
396 | } | |
397 | ||
398 | static int chachapoly_encrypt(struct aead_request *req) | |
399 | { | |
400 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
401 | ||
402 | rctx->cryptlen = req->cryptlen; | |
403 | ||
404 | /* encrypt call chain: | |
405 | * - chacha_encrypt/done() | |
406 | * - poly_genkey/done/continue() | |
407 | * - poly_init/done() | |
408 | * - poly_ad/done() | |
409 | * - poly_adpad/done() | |
410 | * - poly_cipher/done() | |
411 | * - poly_cipherpad/done() | |
412 | * - poly_tail/done/continue() | |
413 | * - poly_copy_tag() | |
414 | */ | |
415 | return chacha_encrypt(req); | |
416 | } | |
417 | ||
418 | static int chachapoly_decrypt(struct aead_request *req) | |
419 | { | |
420 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
421 | ||
422 | if (req->cryptlen < POLY1305_DIGEST_SIZE) | |
423 | return -EINVAL; | |
424 | rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; | |
425 | ||
426 | /* decrypt call chain: | |
427 | * - poly_genkey/done/continue() | |
428 | * - poly_init/done() | |
429 | * - poly_ad/done() | |
430 | * - poly_adpad/done() | |
431 | * - poly_cipher/done() | |
432 | * - poly_cipherpad/done() | |
433 | * - poly_tail/done/continue() | |
434 | * - chacha_decrypt/done() | |
435 | * - poly_verify_tag() | |
436 | */ | |
437 | return poly_genkey(req); | |
438 | } | |
439 | ||
440 | static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key, | |
441 | unsigned int keylen) | |
442 | { | |
443 | struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); | |
444 | int err; | |
445 | ||
446 | if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE) | |
447 | return -EINVAL; | |
448 | ||
449 | keylen -= ctx->saltlen; | |
450 | memcpy(ctx->salt, key + keylen, ctx->saltlen); | |
451 | ||
452 | crypto_ablkcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK); | |
453 | crypto_ablkcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) & | |
454 | CRYPTO_TFM_REQ_MASK); | |
455 | ||
456 | err = crypto_ablkcipher_setkey(ctx->chacha, key, keylen); | |
457 | crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctx->chacha) & | |
458 | CRYPTO_TFM_RES_MASK); | |
459 | return err; | |
460 | } | |
461 | ||
462 | static int chachapoly_setauthsize(struct crypto_aead *tfm, | |
463 | unsigned int authsize) | |
464 | { | |
465 | if (authsize != POLY1305_DIGEST_SIZE) | |
466 | return -EINVAL; | |
467 | ||
468 | return 0; | |
469 | } | |
470 | ||
471 | static int chachapoly_init(struct crypto_tfm *tfm) | |
472 | { | |
473 | struct crypto_instance *inst = (void *)tfm->__crt_alg; | |
474 | struct chachapoly_instance_ctx *ictx = crypto_instance_ctx(inst); | |
475 | struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm); | |
476 | struct crypto_ablkcipher *chacha; | |
477 | struct crypto_ahash *poly; | |
478 | unsigned long align; | |
479 | ||
480 | poly = crypto_spawn_ahash(&ictx->poly); | |
481 | if (IS_ERR(poly)) | |
482 | return PTR_ERR(poly); | |
483 | ||
484 | chacha = crypto_spawn_skcipher(&ictx->chacha); | |
485 | if (IS_ERR(chacha)) { | |
486 | crypto_free_ahash(poly); | |
487 | return PTR_ERR(chacha); | |
488 | } | |
489 | ||
490 | ctx->chacha = chacha; | |
491 | ctx->poly = poly; | |
492 | ctx->saltlen = ictx->saltlen; | |
493 | ||
494 | align = crypto_tfm_alg_alignmask(tfm); | |
495 | align &= ~(crypto_tfm_ctx_alignment() - 1); | |
496 | crypto_aead_set_reqsize(__crypto_aead_cast(tfm), | |
497 | align + offsetof(struct chachapoly_req_ctx, u) + | |
498 | max(offsetof(struct chacha_req, req) + | |
499 | sizeof(struct ablkcipher_request) + | |
500 | crypto_ablkcipher_reqsize(chacha), | |
501 | offsetof(struct poly_req, req) + | |
502 | sizeof(struct ahash_request) + | |
503 | crypto_ahash_reqsize(poly))); | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
508 | static void chachapoly_exit(struct crypto_tfm *tfm) | |
509 | { | |
510 | struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm); | |
511 | ||
512 | crypto_free_ahash(ctx->poly); | |
513 | crypto_free_ablkcipher(ctx->chacha); | |
514 | } | |
515 | ||
516 | static struct crypto_instance *chachapoly_alloc(struct rtattr **tb, | |
517 | const char *name, | |
518 | unsigned int ivsize) | |
519 | { | |
520 | struct crypto_attr_type *algt; | |
521 | struct crypto_instance *inst; | |
522 | struct crypto_alg *chacha; | |
523 | struct crypto_alg *poly; | |
524 | struct ahash_alg *poly_ahash; | |
525 | struct chachapoly_instance_ctx *ctx; | |
526 | const char *chacha_name, *poly_name; | |
527 | int err; | |
528 | ||
529 | if (ivsize > CHACHAPOLY_IV_SIZE) | |
530 | return ERR_PTR(-EINVAL); | |
531 | ||
532 | algt = crypto_get_attr_type(tb); | |
533 | if (IS_ERR(algt)) | |
534 | return ERR_CAST(algt); | |
535 | ||
536 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) | |
537 | return ERR_PTR(-EINVAL); | |
538 | ||
539 | chacha_name = crypto_attr_alg_name(tb[1]); | |
540 | if (IS_ERR(chacha_name)) | |
541 | return ERR_CAST(chacha_name); | |
542 | poly_name = crypto_attr_alg_name(tb[2]); | |
543 | if (IS_ERR(poly_name)) | |
544 | return ERR_CAST(poly_name); | |
545 | ||
546 | poly = crypto_find_alg(poly_name, &crypto_ahash_type, | |
547 | CRYPTO_ALG_TYPE_HASH, | |
548 | CRYPTO_ALG_TYPE_AHASH_MASK); | |
549 | if (IS_ERR(poly)) | |
550 | return ERR_CAST(poly); | |
551 | ||
552 | err = -ENOMEM; | |
553 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
554 | if (!inst) | |
555 | goto out_put_poly; | |
556 | ||
557 | ctx = crypto_instance_ctx(inst); | |
558 | ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; | |
559 | poly_ahash = container_of(poly, struct ahash_alg, halg.base); | |
560 | err = crypto_init_ahash_spawn(&ctx->poly, &poly_ahash->halg, inst); | |
561 | if (err) | |
562 | goto err_free_inst; | |
563 | ||
564 | crypto_set_skcipher_spawn(&ctx->chacha, inst); | |
565 | err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0, | |
566 | crypto_requires_sync(algt->type, | |
567 | algt->mask)); | |
568 | if (err) | |
569 | goto err_drop_poly; | |
570 | ||
571 | chacha = crypto_skcipher_spawn_alg(&ctx->chacha); | |
572 | ||
573 | err = -EINVAL; | |
574 | /* Need 16-byte IV size, including Initial Block Counter value */ | |
575 | if (chacha->cra_ablkcipher.ivsize != CHACHA20_IV_SIZE) | |
576 | goto out_drop_chacha; | |
577 | /* Not a stream cipher? */ | |
578 | if (chacha->cra_blocksize != 1) | |
579 | goto out_drop_chacha; | |
580 | ||
581 | err = -ENAMETOOLONG; | |
582 | if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, | |
583 | "%s(%s,%s)", name, chacha_name, | |
584 | poly_name) >= CRYPTO_MAX_ALG_NAME) | |
585 | goto out_drop_chacha; | |
586 | if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, | |
587 | "%s(%s,%s)", name, chacha->cra_driver_name, | |
588 | poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) | |
589 | goto out_drop_chacha; | |
590 | ||
591 | inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; | |
592 | inst->alg.cra_flags |= (chacha->cra_flags | | |
593 | poly->cra_flags) & CRYPTO_ALG_ASYNC; | |
594 | inst->alg.cra_priority = (chacha->cra_priority + | |
595 | poly->cra_priority) / 2; | |
596 | inst->alg.cra_blocksize = 1; | |
597 | inst->alg.cra_alignmask = chacha->cra_alignmask | poly->cra_alignmask; | |
598 | inst->alg.cra_type = &crypto_nivaead_type; | |
599 | inst->alg.cra_aead.ivsize = ivsize; | |
600 | inst->alg.cra_aead.maxauthsize = POLY1305_DIGEST_SIZE; | |
601 | inst->alg.cra_ctxsize = sizeof(struct chachapoly_ctx) + ctx->saltlen; | |
602 | inst->alg.cra_init = chachapoly_init; | |
603 | inst->alg.cra_exit = chachapoly_exit; | |
604 | inst->alg.cra_aead.encrypt = chachapoly_encrypt; | |
605 | inst->alg.cra_aead.decrypt = chachapoly_decrypt; | |
606 | inst->alg.cra_aead.setkey = chachapoly_setkey; | |
607 | inst->alg.cra_aead.setauthsize = chachapoly_setauthsize; | |
608 | inst->alg.cra_aead.geniv = "seqiv"; | |
609 | ||
610 | out: | |
611 | crypto_mod_put(poly); | |
612 | return inst; | |
613 | ||
614 | out_drop_chacha: | |
615 | crypto_drop_skcipher(&ctx->chacha); | |
616 | err_drop_poly: | |
617 | crypto_drop_ahash(&ctx->poly); | |
618 | err_free_inst: | |
619 | kfree(inst); | |
620 | out_put_poly: | |
621 | inst = ERR_PTR(err); | |
622 | goto out; | |
623 | } | |
624 | ||
625 | static struct crypto_instance *rfc7539_alloc(struct rtattr **tb) | |
626 | { | |
627 | return chachapoly_alloc(tb, "rfc7539", 12); | |
628 | } | |
629 | ||
4db4ad26 MW |
630 | static struct crypto_instance *rfc7539esp_alloc(struct rtattr **tb) |
631 | { | |
632 | return chachapoly_alloc(tb, "rfc7539esp", 8); | |
633 | } | |
634 | ||
71ebc4d1 MW |
635 | static void chachapoly_free(struct crypto_instance *inst) |
636 | { | |
637 | struct chachapoly_instance_ctx *ctx = crypto_instance_ctx(inst); | |
638 | ||
639 | crypto_drop_skcipher(&ctx->chacha); | |
640 | crypto_drop_ahash(&ctx->poly); | |
641 | kfree(inst); | |
642 | } | |
643 | ||
644 | static struct crypto_template rfc7539_tmpl = { | |
645 | .name = "rfc7539", | |
646 | .alloc = rfc7539_alloc, | |
647 | .free = chachapoly_free, | |
648 | .module = THIS_MODULE, | |
649 | }; | |
650 | ||
4db4ad26 MW |
651 | static struct crypto_template rfc7539esp_tmpl = { |
652 | .name = "rfc7539esp", | |
653 | .alloc = rfc7539esp_alloc, | |
654 | .free = chachapoly_free, | |
655 | .module = THIS_MODULE, | |
656 | }; | |
657 | ||
71ebc4d1 MW |
658 | static int __init chacha20poly1305_module_init(void) |
659 | { | |
4db4ad26 MW |
660 | int err; |
661 | ||
662 | err = crypto_register_template(&rfc7539_tmpl); | |
663 | if (err) | |
664 | return err; | |
665 | ||
666 | err = crypto_register_template(&rfc7539esp_tmpl); | |
667 | if (err) | |
668 | crypto_unregister_template(&rfc7539_tmpl); | |
669 | ||
670 | return err; | |
71ebc4d1 MW |
671 | } |
672 | ||
673 | static void __exit chacha20poly1305_module_exit(void) | |
674 | { | |
4db4ad26 | 675 | crypto_unregister_template(&rfc7539esp_tmpl); |
71ebc4d1 MW |
676 | crypto_unregister_template(&rfc7539_tmpl); |
677 | } | |
678 | ||
679 | module_init(chacha20poly1305_module_init); | |
680 | module_exit(chacha20poly1305_module_exit); | |
681 | ||
682 | MODULE_LICENSE("GPL"); | |
683 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); | |
684 | MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); | |
685 | MODULE_ALIAS_CRYPTO("chacha20poly1305"); | |
686 | MODULE_ALIAS_CRYPTO("rfc7539"); | |
4db4ad26 | 687 | MODULE_ALIAS_CRYPTO("rfc7539esp"); |