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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 { | |
71ebc4d1 MW |
57 | u8 iv[CHACHA20_IV_SIZE]; |
58 | struct scatterlist src[1]; | |
59 | struct ablkcipher_request req; /* must be last member */ | |
60 | }; | |
61 | ||
62 | struct chachapoly_req_ctx { | |
c2b7b20a MW |
63 | /* the key we generate for Poly1305 using Chacha20 */ |
64 | u8 key[POLY1305_KEY_SIZE]; | |
71ebc4d1 MW |
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 | ||
c2b7b20a | 297 | static void poly_setkey_done(struct crypto_async_request *areq, int err) |
71ebc4d1 MW |
298 | { |
299 | async_done_continue(areq->data, err, poly_ad); | |
300 | } | |
301 | ||
c2b7b20a | 302 | static int poly_setkey(struct aead_request *req) |
71ebc4d1 MW |
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 | ||
c2b7b20a MW |
309 | sg_init_table(preq->src, 1); |
310 | sg_set_buf(preq->src, rctx->key, sizeof(rctx->key)); | |
311 | ||
71ebc4d1 | 312 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
c2b7b20a | 313 | poly_setkey_done, req); |
71ebc4d1 | 314 | ahash_request_set_tfm(&preq->req, ctx->poly); |
c2b7b20a | 315 | ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key)); |
71ebc4d1 | 316 | |
c2b7b20a | 317 | err = crypto_ahash_update(&preq->req); |
71ebc4d1 MW |
318 | if (err) |
319 | return err; | |
320 | ||
321 | return poly_ad(req); | |
322 | } | |
323 | ||
c2b7b20a | 324 | static void poly_init_done(struct crypto_async_request *areq, int err) |
71ebc4d1 | 325 | { |
c2b7b20a MW |
326 | async_done_continue(areq->data, err, poly_setkey); |
327 | } | |
328 | ||
329 | static int poly_init(struct aead_request *req) | |
330 | { | |
331 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
71ebc4d1 | 332 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
c2b7b20a | 333 | struct poly_req *preq = &rctx->u.poly; |
71ebc4d1 MW |
334 | int err; |
335 | ||
c2b7b20a MW |
336 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
337 | poly_init_done, req); | |
338 | ahash_request_set_tfm(&preq->req, ctx->poly); | |
71ebc4d1 | 339 | |
c2b7b20a | 340 | err = crypto_ahash_init(&preq->req); |
71ebc4d1 MW |
341 | if (err) |
342 | return err; | |
343 | ||
c2b7b20a | 344 | return poly_setkey(req); |
71ebc4d1 MW |
345 | } |
346 | ||
347 | static void poly_genkey_done(struct crypto_async_request *areq, int err) | |
348 | { | |
c2b7b20a | 349 | async_done_continue(areq->data, err, poly_init); |
71ebc4d1 MW |
350 | } |
351 | ||
352 | static int poly_genkey(struct aead_request *req) | |
353 | { | |
354 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
355 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
356 | struct chacha_req *creq = &rctx->u.chacha; | |
357 | int err; | |
358 | ||
359 | sg_init_table(creq->src, 1); | |
c2b7b20a MW |
360 | memset(rctx->key, 0, sizeof(rctx->key)); |
361 | sg_set_buf(creq->src, rctx->key, sizeof(rctx->key)); | |
71ebc4d1 MW |
362 | |
363 | chacha_iv(creq->iv, req, 0); | |
364 | ||
365 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), | |
366 | poly_genkey_done, req); | |
367 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); | |
368 | ablkcipher_request_set_crypt(&creq->req, creq->src, creq->src, | |
369 | POLY1305_KEY_SIZE, creq->iv); | |
370 | ||
371 | err = crypto_ablkcipher_decrypt(&creq->req); | |
372 | if (err) | |
373 | return err; | |
374 | ||
c2b7b20a | 375 | return poly_init(req); |
71ebc4d1 MW |
376 | } |
377 | ||
378 | static void chacha_encrypt_done(struct crypto_async_request *areq, int err) | |
379 | { | |
380 | async_done_continue(areq->data, err, poly_genkey); | |
381 | } | |
382 | ||
383 | static int chacha_encrypt(struct aead_request *req) | |
384 | { | |
385 | struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); | |
386 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
387 | struct chacha_req *creq = &rctx->u.chacha; | |
388 | int err; | |
389 | ||
390 | chacha_iv(creq->iv, req, 1); | |
391 | ||
392 | ablkcipher_request_set_callback(&creq->req, aead_request_flags(req), | |
393 | chacha_encrypt_done, req); | |
394 | ablkcipher_request_set_tfm(&creq->req, ctx->chacha); | |
395 | ablkcipher_request_set_crypt(&creq->req, req->src, req->dst, | |
396 | req->cryptlen, creq->iv); | |
397 | err = crypto_ablkcipher_encrypt(&creq->req); | |
398 | if (err) | |
399 | return err; | |
400 | ||
401 | return poly_genkey(req); | |
402 | } | |
403 | ||
404 | static int chachapoly_encrypt(struct aead_request *req) | |
405 | { | |
406 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
407 | ||
408 | rctx->cryptlen = req->cryptlen; | |
409 | ||
410 | /* encrypt call chain: | |
411 | * - chacha_encrypt/done() | |
c2b7b20a | 412 | * - poly_genkey/done() |
71ebc4d1 | 413 | * - poly_init/done() |
c2b7b20a | 414 | * - poly_setkey/done() |
71ebc4d1 MW |
415 | * - poly_ad/done() |
416 | * - poly_adpad/done() | |
417 | * - poly_cipher/done() | |
418 | * - poly_cipherpad/done() | |
419 | * - poly_tail/done/continue() | |
420 | * - poly_copy_tag() | |
421 | */ | |
422 | return chacha_encrypt(req); | |
423 | } | |
424 | ||
425 | static int chachapoly_decrypt(struct aead_request *req) | |
426 | { | |
427 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); | |
428 | ||
429 | if (req->cryptlen < POLY1305_DIGEST_SIZE) | |
430 | return -EINVAL; | |
431 | rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; | |
432 | ||
433 | /* decrypt call chain: | |
c2b7b20a | 434 | * - poly_genkey/done() |
71ebc4d1 | 435 | * - poly_init/done() |
c2b7b20a | 436 | * - poly_setkey/done() |
71ebc4d1 MW |
437 | * - poly_ad/done() |
438 | * - poly_adpad/done() | |
439 | * - poly_cipher/done() | |
440 | * - poly_cipherpad/done() | |
441 | * - poly_tail/done/continue() | |
442 | * - chacha_decrypt/done() | |
443 | * - poly_verify_tag() | |
444 | */ | |
445 | return poly_genkey(req); | |
446 | } | |
447 | ||
448 | static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key, | |
449 | unsigned int keylen) | |
450 | { | |
451 | struct chachapoly_ctx *ctx = crypto_aead_ctx(aead); | |
452 | int err; | |
453 | ||
454 | if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE) | |
455 | return -EINVAL; | |
456 | ||
457 | keylen -= ctx->saltlen; | |
458 | memcpy(ctx->salt, key + keylen, ctx->saltlen); | |
459 | ||
460 | crypto_ablkcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK); | |
461 | crypto_ablkcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) & | |
462 | CRYPTO_TFM_REQ_MASK); | |
463 | ||
464 | err = crypto_ablkcipher_setkey(ctx->chacha, key, keylen); | |
465 | crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctx->chacha) & | |
466 | CRYPTO_TFM_RES_MASK); | |
467 | return err; | |
468 | } | |
469 | ||
470 | static int chachapoly_setauthsize(struct crypto_aead *tfm, | |
471 | unsigned int authsize) | |
472 | { | |
473 | if (authsize != POLY1305_DIGEST_SIZE) | |
474 | return -EINVAL; | |
475 | ||
476 | return 0; | |
477 | } | |
478 | ||
479 | static int chachapoly_init(struct crypto_tfm *tfm) | |
480 | { | |
481 | struct crypto_instance *inst = (void *)tfm->__crt_alg; | |
482 | struct chachapoly_instance_ctx *ictx = crypto_instance_ctx(inst); | |
483 | struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm); | |
484 | struct crypto_ablkcipher *chacha; | |
485 | struct crypto_ahash *poly; | |
486 | unsigned long align; | |
487 | ||
488 | poly = crypto_spawn_ahash(&ictx->poly); | |
489 | if (IS_ERR(poly)) | |
490 | return PTR_ERR(poly); | |
491 | ||
492 | chacha = crypto_spawn_skcipher(&ictx->chacha); | |
493 | if (IS_ERR(chacha)) { | |
494 | crypto_free_ahash(poly); | |
495 | return PTR_ERR(chacha); | |
496 | } | |
497 | ||
498 | ctx->chacha = chacha; | |
499 | ctx->poly = poly; | |
500 | ctx->saltlen = ictx->saltlen; | |
501 | ||
502 | align = crypto_tfm_alg_alignmask(tfm); | |
503 | align &= ~(crypto_tfm_ctx_alignment() - 1); | |
504 | crypto_aead_set_reqsize(__crypto_aead_cast(tfm), | |
505 | align + offsetof(struct chachapoly_req_ctx, u) + | |
506 | max(offsetof(struct chacha_req, req) + | |
507 | sizeof(struct ablkcipher_request) + | |
508 | crypto_ablkcipher_reqsize(chacha), | |
509 | offsetof(struct poly_req, req) + | |
510 | sizeof(struct ahash_request) + | |
511 | crypto_ahash_reqsize(poly))); | |
512 | ||
513 | return 0; | |
514 | } | |
515 | ||
516 | static void chachapoly_exit(struct crypto_tfm *tfm) | |
517 | { | |
518 | struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm); | |
519 | ||
520 | crypto_free_ahash(ctx->poly); | |
521 | crypto_free_ablkcipher(ctx->chacha); | |
522 | } | |
523 | ||
524 | static struct crypto_instance *chachapoly_alloc(struct rtattr **tb, | |
525 | const char *name, | |
526 | unsigned int ivsize) | |
527 | { | |
528 | struct crypto_attr_type *algt; | |
529 | struct crypto_instance *inst; | |
530 | struct crypto_alg *chacha; | |
531 | struct crypto_alg *poly; | |
532 | struct ahash_alg *poly_ahash; | |
533 | struct chachapoly_instance_ctx *ctx; | |
534 | const char *chacha_name, *poly_name; | |
535 | int err; | |
536 | ||
537 | if (ivsize > CHACHAPOLY_IV_SIZE) | |
538 | return ERR_PTR(-EINVAL); | |
539 | ||
540 | algt = crypto_get_attr_type(tb); | |
541 | if (IS_ERR(algt)) | |
542 | return ERR_CAST(algt); | |
543 | ||
544 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) | |
545 | return ERR_PTR(-EINVAL); | |
546 | ||
547 | chacha_name = crypto_attr_alg_name(tb[1]); | |
548 | if (IS_ERR(chacha_name)) | |
549 | return ERR_CAST(chacha_name); | |
550 | poly_name = crypto_attr_alg_name(tb[2]); | |
551 | if (IS_ERR(poly_name)) | |
552 | return ERR_CAST(poly_name); | |
553 | ||
554 | poly = crypto_find_alg(poly_name, &crypto_ahash_type, | |
555 | CRYPTO_ALG_TYPE_HASH, | |
556 | CRYPTO_ALG_TYPE_AHASH_MASK); | |
557 | if (IS_ERR(poly)) | |
558 | return ERR_CAST(poly); | |
559 | ||
560 | err = -ENOMEM; | |
561 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
562 | if (!inst) | |
563 | goto out_put_poly; | |
564 | ||
565 | ctx = crypto_instance_ctx(inst); | |
566 | ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; | |
567 | poly_ahash = container_of(poly, struct ahash_alg, halg.base); | |
568 | err = crypto_init_ahash_spawn(&ctx->poly, &poly_ahash->halg, inst); | |
569 | if (err) | |
570 | goto err_free_inst; | |
571 | ||
572 | crypto_set_skcipher_spawn(&ctx->chacha, inst); | |
573 | err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0, | |
574 | crypto_requires_sync(algt->type, | |
575 | algt->mask)); | |
576 | if (err) | |
577 | goto err_drop_poly; | |
578 | ||
579 | chacha = crypto_skcipher_spawn_alg(&ctx->chacha); | |
580 | ||
581 | err = -EINVAL; | |
582 | /* Need 16-byte IV size, including Initial Block Counter value */ | |
583 | if (chacha->cra_ablkcipher.ivsize != CHACHA20_IV_SIZE) | |
584 | goto out_drop_chacha; | |
585 | /* Not a stream cipher? */ | |
586 | if (chacha->cra_blocksize != 1) | |
587 | goto out_drop_chacha; | |
588 | ||
589 | err = -ENAMETOOLONG; | |
590 | if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, | |
591 | "%s(%s,%s)", name, chacha_name, | |
592 | poly_name) >= CRYPTO_MAX_ALG_NAME) | |
593 | goto out_drop_chacha; | |
594 | if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, | |
595 | "%s(%s,%s)", name, chacha->cra_driver_name, | |
596 | poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) | |
597 | goto out_drop_chacha; | |
598 | ||
599 | inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD; | |
600 | inst->alg.cra_flags |= (chacha->cra_flags | | |
601 | poly->cra_flags) & CRYPTO_ALG_ASYNC; | |
602 | inst->alg.cra_priority = (chacha->cra_priority + | |
603 | poly->cra_priority) / 2; | |
604 | inst->alg.cra_blocksize = 1; | |
605 | inst->alg.cra_alignmask = chacha->cra_alignmask | poly->cra_alignmask; | |
606 | inst->alg.cra_type = &crypto_nivaead_type; | |
607 | inst->alg.cra_aead.ivsize = ivsize; | |
608 | inst->alg.cra_aead.maxauthsize = POLY1305_DIGEST_SIZE; | |
609 | inst->alg.cra_ctxsize = sizeof(struct chachapoly_ctx) + ctx->saltlen; | |
610 | inst->alg.cra_init = chachapoly_init; | |
611 | inst->alg.cra_exit = chachapoly_exit; | |
612 | inst->alg.cra_aead.encrypt = chachapoly_encrypt; | |
613 | inst->alg.cra_aead.decrypt = chachapoly_decrypt; | |
614 | inst->alg.cra_aead.setkey = chachapoly_setkey; | |
615 | inst->alg.cra_aead.setauthsize = chachapoly_setauthsize; | |
616 | inst->alg.cra_aead.geniv = "seqiv"; | |
617 | ||
618 | out: | |
619 | crypto_mod_put(poly); | |
620 | return inst; | |
621 | ||
622 | out_drop_chacha: | |
623 | crypto_drop_skcipher(&ctx->chacha); | |
624 | err_drop_poly: | |
625 | crypto_drop_ahash(&ctx->poly); | |
626 | err_free_inst: | |
627 | kfree(inst); | |
628 | out_put_poly: | |
629 | inst = ERR_PTR(err); | |
630 | goto out; | |
631 | } | |
632 | ||
633 | static struct crypto_instance *rfc7539_alloc(struct rtattr **tb) | |
634 | { | |
635 | return chachapoly_alloc(tb, "rfc7539", 12); | |
636 | } | |
637 | ||
4db4ad26 MW |
638 | static struct crypto_instance *rfc7539esp_alloc(struct rtattr **tb) |
639 | { | |
640 | return chachapoly_alloc(tb, "rfc7539esp", 8); | |
641 | } | |
642 | ||
71ebc4d1 MW |
643 | static void chachapoly_free(struct crypto_instance *inst) |
644 | { | |
645 | struct chachapoly_instance_ctx *ctx = crypto_instance_ctx(inst); | |
646 | ||
647 | crypto_drop_skcipher(&ctx->chacha); | |
648 | crypto_drop_ahash(&ctx->poly); | |
649 | kfree(inst); | |
650 | } | |
651 | ||
652 | static struct crypto_template rfc7539_tmpl = { | |
653 | .name = "rfc7539", | |
654 | .alloc = rfc7539_alloc, | |
655 | .free = chachapoly_free, | |
656 | .module = THIS_MODULE, | |
657 | }; | |
658 | ||
4db4ad26 MW |
659 | static struct crypto_template rfc7539esp_tmpl = { |
660 | .name = "rfc7539esp", | |
661 | .alloc = rfc7539esp_alloc, | |
662 | .free = chachapoly_free, | |
663 | .module = THIS_MODULE, | |
664 | }; | |
665 | ||
71ebc4d1 MW |
666 | static int __init chacha20poly1305_module_init(void) |
667 | { | |
4db4ad26 MW |
668 | int err; |
669 | ||
670 | err = crypto_register_template(&rfc7539_tmpl); | |
671 | if (err) | |
672 | return err; | |
673 | ||
674 | err = crypto_register_template(&rfc7539esp_tmpl); | |
675 | if (err) | |
676 | crypto_unregister_template(&rfc7539_tmpl); | |
677 | ||
678 | return err; | |
71ebc4d1 MW |
679 | } |
680 | ||
681 | static void __exit chacha20poly1305_module_exit(void) | |
682 | { | |
4db4ad26 | 683 | crypto_unregister_template(&rfc7539esp_tmpl); |
71ebc4d1 MW |
684 | crypto_unregister_template(&rfc7539_tmpl); |
685 | } | |
686 | ||
687 | module_init(chacha20poly1305_module_init); | |
688 | module_exit(chacha20poly1305_module_exit); | |
689 | ||
690 | MODULE_LICENSE("GPL"); | |
691 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); | |
692 | MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); | |
693 | MODULE_ALIAS_CRYPTO("chacha20poly1305"); | |
694 | MODULE_ALIAS_CRYPTO("rfc7539"); | |
4db4ad26 | 695 | MODULE_ALIAS_CRYPTO("rfc7539esp"); |