Commit | Line | Data |
---|---|---|
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> | |
31d7247d | 16 | #include <crypto/chacha20.h> |
2546f811 | 17 | #include <crypto/poly1305.h> |
71ebc4d1 MW |
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 | ||
71ebc4d1 MW |
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 { | |
1e1f0061 | 34 | struct crypto_skcipher *chacha; |
71ebc4d1 MW |
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 { | |
71ebc4d1 MW |
54 | u8 iv[CHACHA20_IV_SIZE]; |
55 | struct scatterlist src[1]; | |
1e1f0061 | 56 | struct skcipher_request req; /* must be last member */ |
71ebc4d1 MW |
57 | }; |
58 | ||
59 | struct chachapoly_req_ctx { | |
74790922 HX |
60 | struct scatterlist src[2]; |
61 | struct scatterlist dst[2]; | |
c2b7b20a MW |
62 | /* the key we generate for Poly1305 using Chacha20 */ |
63 | u8 key[POLY1305_KEY_SIZE]; | |
71ebc4d1 MW |
64 | /* calculated Poly1305 tag */ |
65 | u8 tag[POLY1305_DIGEST_SIZE]; | |
66 | /* length of data to en/decrypt, without ICV */ | |
67 | unsigned int cryptlen; | |
74790922 HX |
68 | /* Actual AD, excluding IV */ |
69 | unsigned int assoclen; | |
71ebc4d1 MW |
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 | CHACHA20_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 | ||
74790922 HX |
102 | scatterwalk_map_and_copy(tag, req->src, |
103 | req->assoclen + rctx->cryptlen, | |
104 | sizeof(tag), 0); | |
71ebc4d1 MW |
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 | ||
74790922 HX |
114 | scatterwalk_map_and_copy(rctx->tag, req->dst, |
115 | req->assoclen + rctx->cryptlen, | |
71ebc4d1 MW |
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; | |
74790922 | 130 | struct scatterlist *src, *dst; |
71ebc4d1 MW |
131 | int err; |
132 | ||
161151d7 JD |
133 | if (rctx->cryptlen == 0) |
134 | goto skip; | |
135 | ||
71ebc4d1 MW |
136 | chacha_iv(creq->iv, req, 1); |
137 | ||
74790922 HX |
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 | ||
1e1f0061 HX |
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); | |
71ebc4d1 MW |
153 | if (err) |
154 | return err; | |
155 | ||
161151d7 | 156 | skip: |
71ebc4d1 MW |
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 | { | |
74790922 HX |
177 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); |
178 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); | |
71ebc4d1 MW |
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); | |
74790922 | 185 | len = cpu_to_le64(rctx->assoclen); |
71ebc4d1 MW |
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 | ||
74790922 HX |
250 | sg_init_table(rctx->src, 2); |
251 | crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen); | |
252 | ||
71ebc4d1 MW |
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 | ||
74790922 | 278 | padlen = (bs - (rctx->assoclen % bs)) % bs; |
71ebc4d1 MW |
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); | |
74790922 | 310 | ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen); |
71ebc4d1 MW |
311 | |
312 | err = crypto_ahash_update(&preq->req); | |
313 | if (err) | |
314 | return err; | |
315 | ||
316 | return poly_adpad(req); | |
317 | } | |
318 | ||
c2b7b20a | 319 | static void poly_setkey_done(struct crypto_async_request *areq, int err) |
71ebc4d1 MW |
320 | { |
321 | async_done_continue(areq->data, err, poly_ad); | |
322 | } | |
323 | ||
c2b7b20a | 324 | static int poly_setkey(struct aead_request *req) |
71ebc4d1 MW |
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 | ||
c2b7b20a MW |
331 | sg_init_table(preq->src, 1); |
332 | sg_set_buf(preq->src, rctx->key, sizeof(rctx->key)); | |
333 | ||
71ebc4d1 | 334 | ahash_request_set_callback(&preq->req, aead_request_flags(req), |
c2b7b20a | 335 | poly_setkey_done, req); |
71ebc4d1 | 336 | ahash_request_set_tfm(&preq->req, ctx->poly); |
c2b7b20a | 337 | ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key)); |
71ebc4d1 | 338 | |
c2b7b20a | 339 | err = crypto_ahash_update(&preq->req); |
71ebc4d1 MW |
340 | if (err) |
341 | return err; | |
342 | ||
343 | return poly_ad(req); | |
344 | } | |
345 | ||
c2b7b20a | 346 | static void poly_init_done(struct crypto_async_request *areq, int err) |
71ebc4d1 | 347 | { |
c2b7b20a MW |
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)); | |
71ebc4d1 | 354 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
c2b7b20a | 355 | struct poly_req *preq = &rctx->u.poly; |
71ebc4d1 MW |
356 | int err; |
357 | ||
c2b7b20a MW |
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); | |
71ebc4d1 | 361 | |
c2b7b20a | 362 | err = crypto_ahash_init(&preq->req); |
71ebc4d1 MW |
363 | if (err) |
364 | return err; | |
365 | ||
c2b7b20a | 366 | return poly_setkey(req); |
71ebc4d1 MW |
367 | } |
368 | ||
369 | static void poly_genkey_done(struct crypto_async_request *areq, int err) | |
370 | { | |
c2b7b20a | 371 | async_done_continue(areq->data, err, poly_init); |
71ebc4d1 MW |
372 | } |
373 | ||
374 | static int poly_genkey(struct aead_request *req) | |
375 | { | |
74790922 HX |
376 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); |
377 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); | |
71ebc4d1 MW |
378 | struct chachapoly_req_ctx *rctx = aead_request_ctx(req); |
379 | struct chacha_req *creq = &rctx->u.chacha; | |
380 | int err; | |
381 | ||
74790922 HX |
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 | ||
71ebc4d1 | 390 | sg_init_table(creq->src, 1); |
c2b7b20a MW |
391 | memset(rctx->key, 0, sizeof(rctx->key)); |
392 | sg_set_buf(creq->src, rctx->key, sizeof(rctx->key)); | |
71ebc4d1 MW |
393 | |
394 | chacha_iv(creq->iv, req, 0); | |
395 | ||
1e1f0061 HX |
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); | |
71ebc4d1 | 401 | |
1e1f0061 | 402 | err = crypto_skcipher_decrypt(&creq->req); |
71ebc4d1 MW |
403 | if (err) |
404 | return err; | |
405 | ||
c2b7b20a | 406 | return poly_init(req); |
71ebc4d1 MW |
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; | |
74790922 | 419 | struct scatterlist *src, *dst; |
71ebc4d1 MW |
420 | int err; |
421 | ||
161151d7 JD |
422 | if (req->cryptlen == 0) |
423 | goto skip; | |
424 | ||
71ebc4d1 MW |
425 | chacha_iv(creq->iv, req, 1); |
426 | ||
74790922 HX |
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 | ||
1e1f0061 HX |
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); | |
71ebc4d1 MW |
442 | if (err) |
443 | return err; | |
444 | ||
161151d7 | 445 | skip: |
71ebc4d1 MW |
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() | |
c2b7b20a | 457 | * - poly_genkey/done() |
71ebc4d1 | 458 | * - poly_init/done() |
c2b7b20a | 459 | * - poly_setkey/done() |
71ebc4d1 MW |
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 | ||
71ebc4d1 MW |
474 | rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE; |
475 | ||
476 | /* decrypt call chain: | |
c2b7b20a | 477 | * - poly_genkey/done() |
71ebc4d1 | 478 | * - poly_init/done() |
c2b7b20a | 479 | * - poly_setkey/done() |
71ebc4d1 MW |
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 + CHACHA20_KEY_SIZE) | |
498 | return -EINVAL; | |
499 | ||
500 | keylen -= ctx->saltlen; | |
501 | memcpy(ctx->salt, key + keylen, ctx->saltlen); | |
502 | ||
1e1f0061 HX |
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); | |
71ebc4d1 | 506 | |
1e1f0061 HX |
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); | |
71ebc4d1 MW |
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 | ||
74790922 | 522 | static int chachapoly_init(struct crypto_aead *tfm) |
71ebc4d1 | 523 | { |
74790922 HX |
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); | |
1e1f0061 | 527 | struct crypto_skcipher *chacha; |
71ebc4d1 MW |
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 | ||
1e1f0061 | 535 | chacha = crypto_spawn_skcipher2(&ictx->chacha); |
71ebc4d1 MW |
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 | ||
74790922 | 545 | align = crypto_aead_alignmask(tfm); |
71ebc4d1 | 546 | align &= ~(crypto_tfm_ctx_alignment() - 1); |
74790922 HX |
547 | crypto_aead_set_reqsize( |
548 | tfm, | |
549 | align + offsetof(struct chachapoly_req_ctx, u) + | |
550 | max(offsetof(struct chacha_req, req) + | |
1e1f0061 HX |
551 | sizeof(struct skcipher_request) + |
552 | crypto_skcipher_reqsize(chacha), | |
74790922 HX |
553 | offsetof(struct poly_req, req) + |
554 | sizeof(struct ahash_request) + | |
555 | crypto_ahash_reqsize(poly))); | |
71ebc4d1 MW |
556 | |
557 | return 0; | |
558 | } | |
559 | ||
74790922 | 560 | static void chachapoly_exit(struct crypto_aead *tfm) |
71ebc4d1 | 561 | { |
74790922 | 562 | struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); |
71ebc4d1 MW |
563 | |
564 | crypto_free_ahash(ctx->poly); | |
1e1f0061 | 565 | crypto_free_skcipher(ctx->chacha); |
71ebc4d1 MW |
566 | } |
567 | ||
74790922 HX |
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) | |
71ebc4d1 MW |
579 | { |
580 | struct crypto_attr_type *algt; | |
74790922 | 581 | struct aead_instance *inst; |
1e1f0061 | 582 | struct skcipher_alg *chacha; |
71ebc4d1 | 583 | struct crypto_alg *poly; |
74790922 | 584 | struct hash_alg_common *poly_hash; |
71ebc4d1 MW |
585 | struct chachapoly_instance_ctx *ctx; |
586 | const char *chacha_name, *poly_name; | |
587 | int err; | |
588 | ||
589 | if (ivsize > CHACHAPOLY_IV_SIZE) | |
74790922 | 590 | return -EINVAL; |
71ebc4d1 MW |
591 | |
592 | algt = crypto_get_attr_type(tb); | |
593 | if (IS_ERR(algt)) | |
74790922 | 594 | return PTR_ERR(algt); |
71ebc4d1 | 595 | |
5e4b8c1f | 596 | if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask) |
74790922 | 597 | return -EINVAL; |
71ebc4d1 MW |
598 | |
599 | chacha_name = crypto_attr_alg_name(tb[1]); | |
600 | if (IS_ERR(chacha_name)) | |
74790922 | 601 | return PTR_ERR(chacha_name); |
71ebc4d1 MW |
602 | poly_name = crypto_attr_alg_name(tb[2]); |
603 | if (IS_ERR(poly_name)) | |
74790922 | 604 | return PTR_ERR(poly_name); |
71ebc4d1 MW |
605 | |
606 | poly = crypto_find_alg(poly_name, &crypto_ahash_type, | |
607 | CRYPTO_ALG_TYPE_HASH, | |
1e1f0061 HX |
608 | CRYPTO_ALG_TYPE_AHASH_MASK | |
609 | crypto_requires_sync(algt->type, | |
610 | algt->mask)); | |
71ebc4d1 | 611 | if (IS_ERR(poly)) |
74790922 | 612 | return PTR_ERR(poly); |
71ebc4d1 MW |
613 | |
614 | err = -ENOMEM; | |
615 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
616 | if (!inst) | |
617 | goto out_put_poly; | |
618 | ||
74790922 | 619 | ctx = aead_instance_ctx(inst); |
71ebc4d1 | 620 | ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize; |
74790922 HX |
621 | poly_hash = __crypto_hash_alg_common(poly); |
622 | err = crypto_init_ahash_spawn(&ctx->poly, poly_hash, | |
623 | aead_crypto_instance(inst)); | |
71ebc4d1 MW |
624 | if (err) |
625 | goto err_free_inst; | |
626 | ||
74790922 | 627 | crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst)); |
1e1f0061 HX |
628 | err = crypto_grab_skcipher2(&ctx->chacha, chacha_name, 0, |
629 | crypto_requires_sync(algt->type, | |
630 | algt->mask)); | |
71ebc4d1 MW |
631 | if (err) |
632 | goto err_drop_poly; | |
633 | ||
1e1f0061 | 634 | chacha = crypto_spawn_skcipher_alg(&ctx->chacha); |
71ebc4d1 MW |
635 | |
636 | err = -EINVAL; | |
637 | /* Need 16-byte IV size, including Initial Block Counter value */ | |
1e1f0061 | 638 | if (crypto_skcipher_alg_ivsize(chacha) != CHACHA20_IV_SIZE) |
71ebc4d1 MW |
639 | goto out_drop_chacha; |
640 | /* Not a stream cipher? */ | |
1e1f0061 | 641 | if (chacha->base.cra_blocksize != 1) |
71ebc4d1 MW |
642 | goto out_drop_chacha; |
643 | ||
644 | err = -ENAMETOOLONG; | |
74790922 | 645 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
71ebc4d1 MW |
646 | "%s(%s,%s)", name, chacha_name, |
647 | poly_name) >= CRYPTO_MAX_ALG_NAME) | |
648 | goto out_drop_chacha; | |
74790922 | 649 | if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, |
1e1f0061 | 650 | "%s(%s,%s)", name, chacha->base.cra_driver_name, |
71ebc4d1 MW |
651 | poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME) |
652 | goto out_drop_chacha; | |
653 | ||
1e1f0061 | 654 | inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) & |
74790922 | 655 | CRYPTO_ALG_ASYNC; |
1e1f0061 | 656 | inst->alg.base.cra_priority = (chacha->base.cra_priority + |
74790922 HX |
657 | poly->cra_priority) / 2; |
658 | inst->alg.base.cra_blocksize = 1; | |
1e1f0061 | 659 | inst->alg.base.cra_alignmask = chacha->base.cra_alignmask | |
74790922 HX |
660 | poly->cra_alignmask; |
661 | inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) + | |
662 | ctx->saltlen; | |
663 | inst->alg.ivsize = ivsize; | |
1e1f0061 | 664 | inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha); |
74790922 HX |
665 | inst->alg.maxauthsize = POLY1305_DIGEST_SIZE; |
666 | inst->alg.init = chachapoly_init; | |
667 | inst->alg.exit = chachapoly_exit; | |
668 | inst->alg.encrypt = chachapoly_encrypt; | |
669 | inst->alg.decrypt = chachapoly_decrypt; | |
670 | inst->alg.setkey = chachapoly_setkey; | |
671 | inst->alg.setauthsize = chachapoly_setauthsize; | |
672 | ||
673 | inst->free = chachapoly_free; | |
674 | ||
675 | err = aead_register_instance(tmpl, inst); | |
676 | if (err) | |
677 | goto out_drop_chacha; | |
678 | ||
679 | out_put_poly: | |
71ebc4d1 | 680 | crypto_mod_put(poly); |
74790922 | 681 | return err; |
71ebc4d1 MW |
682 | |
683 | out_drop_chacha: | |
684 | crypto_drop_skcipher(&ctx->chacha); | |
685 | err_drop_poly: | |
686 | crypto_drop_ahash(&ctx->poly); | |
687 | err_free_inst: | |
688 | kfree(inst); | |
74790922 | 689 | goto out_put_poly; |
71ebc4d1 MW |
690 | } |
691 | ||
74790922 | 692 | static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb) |
4db4ad26 | 693 | { |
74790922 | 694 | return chachapoly_create(tmpl, tb, "rfc7539", 12); |
4db4ad26 MW |
695 | } |
696 | ||
74790922 | 697 | static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb) |
71ebc4d1 | 698 | { |
74790922 | 699 | return chachapoly_create(tmpl, tb, "rfc7539esp", 8); |
71ebc4d1 MW |
700 | } |
701 | ||
702 | static struct crypto_template rfc7539_tmpl = { | |
703 | .name = "rfc7539", | |
74790922 | 704 | .create = rfc7539_create, |
71ebc4d1 MW |
705 | .module = THIS_MODULE, |
706 | }; | |
707 | ||
4db4ad26 MW |
708 | static struct crypto_template rfc7539esp_tmpl = { |
709 | .name = "rfc7539esp", | |
74790922 | 710 | .create = rfc7539esp_create, |
4db4ad26 MW |
711 | .module = THIS_MODULE, |
712 | }; | |
713 | ||
71ebc4d1 MW |
714 | static int __init chacha20poly1305_module_init(void) |
715 | { | |
4db4ad26 MW |
716 | int err; |
717 | ||
718 | err = crypto_register_template(&rfc7539_tmpl); | |
719 | if (err) | |
720 | return err; | |
721 | ||
722 | err = crypto_register_template(&rfc7539esp_tmpl); | |
723 | if (err) | |
724 | crypto_unregister_template(&rfc7539_tmpl); | |
725 | ||
726 | return err; | |
71ebc4d1 MW |
727 | } |
728 | ||
729 | static void __exit chacha20poly1305_module_exit(void) | |
730 | { | |
4db4ad26 | 731 | crypto_unregister_template(&rfc7539esp_tmpl); |
71ebc4d1 MW |
732 | crypto_unregister_template(&rfc7539_tmpl); |
733 | } | |
734 | ||
735 | module_init(chacha20poly1305_module_init); | |
736 | module_exit(chacha20poly1305_module_exit); | |
737 | ||
738 | MODULE_LICENSE("GPL"); | |
739 | MODULE_AUTHOR("Martin Willi <martin@strongswan.org>"); | |
740 | MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD"); | |
71ebc4d1 | 741 | MODULE_ALIAS_CRYPTO("rfc7539"); |
4db4ad26 | 742 | MODULE_ALIAS_CRYPTO("rfc7539esp"); |