Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ChaCha20-Poly1305 AEAD, RFC7539
4 *
5 * Copyright (C) 2015 Martin Willi
6 */
7
8#include <crypto/internal/aead.h>
9#include <crypto/internal/hash.h>
10#include <crypto/internal/skcipher.h>
11#include <crypto/scatterwalk.h>
12#include <crypto/chacha.h>
13#include <crypto/poly1305.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18
19#include "internal.h"
20
21struct chachapoly_instance_ctx {
22 struct crypto_skcipher_spawn chacha;
23 struct crypto_ahash_spawn poly;
24 unsigned int saltlen;
25};
26
27struct chachapoly_ctx {
28 struct crypto_skcipher *chacha;
29 struct crypto_ahash *poly;
30 /* key bytes we use for the ChaCha20 IV */
31 unsigned int saltlen;
32 u8 salt[];
33};
34
35struct poly_req {
36 /* zero byte padding for AD/ciphertext, as needed */
37 u8 pad[POLY1305_BLOCK_SIZE];
38 /* tail data with AD/ciphertext lengths */
39 struct {
40 __le64 assoclen;
41 __le64 cryptlen;
42 } tail;
43 struct scatterlist src[1];
44 struct ahash_request req; /* must be last member */
45};
46
47struct chacha_req {
48 u8 iv[CHACHA_IV_SIZE];
49 struct scatterlist src[1];
50 struct skcipher_request req; /* must be last member */
51};
52
53struct chachapoly_req_ctx {
54 struct scatterlist src[2];
55 struct scatterlist dst[2];
56 /* the key we generate for Poly1305 using Chacha20 */
57 u8 key[POLY1305_KEY_SIZE];
58 /* calculated Poly1305 tag */
59 u8 tag[POLY1305_DIGEST_SIZE];
60 /* length of data to en/decrypt, without ICV */
61 unsigned int cryptlen;
62 /* Actual AD, excluding IV */
63 unsigned int assoclen;
64 /* request flags, with MAY_SLEEP cleared if needed */
65 u32 flags;
66 union {
67 struct poly_req poly;
68 struct chacha_req chacha;
69 } u;
70};
71
72static inline void async_done_continue(struct aead_request *req, int err,
73 int (*cont)(struct aead_request *))
74{
75 if (!err) {
76 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
77
78 rctx->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
79 err = cont(req);
80 }
81
82 if (err != -EINPROGRESS && err != -EBUSY)
83 aead_request_complete(req, err);
84}
85
86static 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
97static 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
110static 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
120static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
121{
122 async_done_continue(areq->data, err, poly_verify_tag);
123}
124
125static 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 src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
139 dst = src;
140 if (req->src != req->dst)
141 dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
142
143 skcipher_request_set_callback(&creq->req, rctx->flags,
144 chacha_decrypt_done, req);
145 skcipher_request_set_tfm(&creq->req, ctx->chacha);
146 skcipher_request_set_crypt(&creq->req, src, dst,
147 rctx->cryptlen, creq->iv);
148 err = crypto_skcipher_decrypt(&creq->req);
149 if (err)
150 return err;
151
152skip:
153 return poly_verify_tag(req);
154}
155
156static int poly_tail_continue(struct aead_request *req)
157{
158 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
159
160 if (rctx->cryptlen == req->cryptlen) /* encrypting */
161 return poly_copy_tag(req);
162
163 return chacha_decrypt(req);
164}
165
166static void poly_tail_done(struct crypto_async_request *areq, int err)
167{
168 async_done_continue(areq->data, err, poly_tail_continue);
169}
170
171static int poly_tail(struct aead_request *req)
172{
173 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
174 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
175 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
176 struct poly_req *preq = &rctx->u.poly;
177 int err;
178
179 preq->tail.assoclen = cpu_to_le64(rctx->assoclen);
180 preq->tail.cryptlen = cpu_to_le64(rctx->cryptlen);
181 sg_init_one(preq->src, &preq->tail, sizeof(preq->tail));
182
183 ahash_request_set_callback(&preq->req, rctx->flags,
184 poly_tail_done, req);
185 ahash_request_set_tfm(&preq->req, ctx->poly);
186 ahash_request_set_crypt(&preq->req, preq->src,
187 rctx->tag, sizeof(preq->tail));
188
189 err = crypto_ahash_finup(&preq->req);
190 if (err)
191 return err;
192
193 return poly_tail_continue(req);
194}
195
196static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
197{
198 async_done_continue(areq->data, err, poly_tail);
199}
200
201static int poly_cipherpad(struct aead_request *req)
202{
203 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
204 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
205 struct poly_req *preq = &rctx->u.poly;
206 unsigned int padlen;
207 int err;
208
209 padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE;
210 memset(preq->pad, 0, sizeof(preq->pad));
211 sg_init_one(preq->src, preq->pad, padlen);
212
213 ahash_request_set_callback(&preq->req, rctx->flags,
214 poly_cipherpad_done, req);
215 ahash_request_set_tfm(&preq->req, ctx->poly);
216 ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
217
218 err = crypto_ahash_update(&preq->req);
219 if (err)
220 return err;
221
222 return poly_tail(req);
223}
224
225static void poly_cipher_done(struct crypto_async_request *areq, int err)
226{
227 async_done_continue(areq->data, err, poly_cipherpad);
228}
229
230static int poly_cipher(struct aead_request *req)
231{
232 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
233 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
234 struct poly_req *preq = &rctx->u.poly;
235 struct scatterlist *crypt = req->src;
236 int err;
237
238 if (rctx->cryptlen == req->cryptlen) /* encrypting */
239 crypt = req->dst;
240
241 crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen);
242
243 ahash_request_set_callback(&preq->req, rctx->flags,
244 poly_cipher_done, req);
245 ahash_request_set_tfm(&preq->req, ctx->poly);
246 ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);
247
248 err = crypto_ahash_update(&preq->req);
249 if (err)
250 return err;
251
252 return poly_cipherpad(req);
253}
254
255static void poly_adpad_done(struct crypto_async_request *areq, int err)
256{
257 async_done_continue(areq->data, err, poly_cipher);
258}
259
260static int poly_adpad(struct aead_request *req)
261{
262 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
263 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
264 struct poly_req *preq = &rctx->u.poly;
265 unsigned int padlen;
266 int err;
267
268 padlen = -rctx->assoclen % POLY1305_BLOCK_SIZE;
269 memset(preq->pad, 0, sizeof(preq->pad));
270 sg_init_one(preq->src, preq->pad, padlen);
271
272 ahash_request_set_callback(&preq->req, rctx->flags,
273 poly_adpad_done, req);
274 ahash_request_set_tfm(&preq->req, ctx->poly);
275 ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
276
277 err = crypto_ahash_update(&preq->req);
278 if (err)
279 return err;
280
281 return poly_cipher(req);
282}
283
284static void poly_ad_done(struct crypto_async_request *areq, int err)
285{
286 async_done_continue(areq->data, err, poly_adpad);
287}
288
289static int poly_ad(struct aead_request *req)
290{
291 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
292 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
293 struct poly_req *preq = &rctx->u.poly;
294 int err;
295
296 ahash_request_set_callback(&preq->req, rctx->flags,
297 poly_ad_done, req);
298 ahash_request_set_tfm(&preq->req, ctx->poly);
299 ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen);
300
301 err = crypto_ahash_update(&preq->req);
302 if (err)
303 return err;
304
305 return poly_adpad(req);
306}
307
308static void poly_setkey_done(struct crypto_async_request *areq, int err)
309{
310 async_done_continue(areq->data, err, poly_ad);
311}
312
313static int poly_setkey(struct aead_request *req)
314{
315 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
316 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
317 struct poly_req *preq = &rctx->u.poly;
318 int err;
319
320 sg_init_one(preq->src, rctx->key, sizeof(rctx->key));
321
322 ahash_request_set_callback(&preq->req, rctx->flags,
323 poly_setkey_done, req);
324 ahash_request_set_tfm(&preq->req, ctx->poly);
325 ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));
326
327 err = crypto_ahash_update(&preq->req);
328 if (err)
329 return err;
330
331 return poly_ad(req);
332}
333
334static void poly_init_done(struct crypto_async_request *areq, int err)
335{
336 async_done_continue(areq->data, err, poly_setkey);
337}
338
339static int poly_init(struct aead_request *req)
340{
341 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
342 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
343 struct poly_req *preq = &rctx->u.poly;
344 int err;
345
346 ahash_request_set_callback(&preq->req, rctx->flags,
347 poly_init_done, req);
348 ahash_request_set_tfm(&preq->req, ctx->poly);
349
350 err = crypto_ahash_init(&preq->req);
351 if (err)
352 return err;
353
354 return poly_setkey(req);
355}
356
357static void poly_genkey_done(struct crypto_async_request *areq, int err)
358{
359 async_done_continue(areq->data, err, poly_init);
360}
361
362static int poly_genkey(struct aead_request *req)
363{
364 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
365 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
366 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
367 struct chacha_req *creq = &rctx->u.chacha;
368 int err;
369
370 rctx->assoclen = req->assoclen;
371
372 if (crypto_aead_ivsize(tfm) == 8) {
373 if (rctx->assoclen < 8)
374 return -EINVAL;
375 rctx->assoclen -= 8;
376 }
377
378 memset(rctx->key, 0, sizeof(rctx->key));
379 sg_init_one(creq->src, rctx->key, sizeof(rctx->key));
380
381 chacha_iv(creq->iv, req, 0);
382
383 skcipher_request_set_callback(&creq->req, rctx->flags,
384 poly_genkey_done, req);
385 skcipher_request_set_tfm(&creq->req, ctx->chacha);
386 skcipher_request_set_crypt(&creq->req, creq->src, creq->src,
387 POLY1305_KEY_SIZE, creq->iv);
388
389 err = crypto_skcipher_decrypt(&creq->req);
390 if (err)
391 return err;
392
393 return poly_init(req);
394}
395
396static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
397{
398 async_done_continue(areq->data, err, poly_genkey);
399}
400
401static int chacha_encrypt(struct aead_request *req)
402{
403 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
404 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
405 struct chacha_req *creq = &rctx->u.chacha;
406 struct scatterlist *src, *dst;
407 int err;
408
409 if (req->cryptlen == 0)
410 goto skip;
411
412 chacha_iv(creq->iv, req, 1);
413
414 src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
415 dst = src;
416 if (req->src != req->dst)
417 dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
418
419 skcipher_request_set_callback(&creq->req, rctx->flags,
420 chacha_encrypt_done, req);
421 skcipher_request_set_tfm(&creq->req, ctx->chacha);
422 skcipher_request_set_crypt(&creq->req, src, dst,
423 req->cryptlen, creq->iv);
424 err = crypto_skcipher_encrypt(&creq->req);
425 if (err)
426 return err;
427
428skip:
429 return poly_genkey(req);
430}
431
432static int chachapoly_encrypt(struct aead_request *req)
433{
434 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
435
436 rctx->cryptlen = req->cryptlen;
437 rctx->flags = aead_request_flags(req);
438
439 /* encrypt call chain:
440 * - chacha_encrypt/done()
441 * - poly_genkey/done()
442 * - poly_init/done()
443 * - poly_setkey/done()
444 * - poly_ad/done()
445 * - poly_adpad/done()
446 * - poly_cipher/done()
447 * - poly_cipherpad/done()
448 * - poly_tail/done/continue()
449 * - poly_copy_tag()
450 */
451 return chacha_encrypt(req);
452}
453
454static int chachapoly_decrypt(struct aead_request *req)
455{
456 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
457
458 rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
459 rctx->flags = aead_request_flags(req);
460
461 /* decrypt call chain:
462 * - poly_genkey/done()
463 * - poly_init/done()
464 * - poly_setkey/done()
465 * - poly_ad/done()
466 * - poly_adpad/done()
467 * - poly_cipher/done()
468 * - poly_cipherpad/done()
469 * - poly_tail/done/continue()
470 * - chacha_decrypt/done()
471 * - poly_verify_tag()
472 */
473 return poly_genkey(req);
474}
475
476static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
477 unsigned int keylen)
478{
479 struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
480 int err;
481
482 if (keylen != ctx->saltlen + CHACHA_KEY_SIZE)
483 return -EINVAL;
484
485 keylen -= ctx->saltlen;
486 memcpy(ctx->salt, key + keylen, ctx->saltlen);
487
488 crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
489 crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
490 CRYPTO_TFM_REQ_MASK);
491
492 err = crypto_skcipher_setkey(ctx->chacha, key, keylen);
493 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctx->chacha) &
494 CRYPTO_TFM_RES_MASK);
495 return err;
496}
497
498static int chachapoly_setauthsize(struct crypto_aead *tfm,
499 unsigned int authsize)
500{
501 if (authsize != POLY1305_DIGEST_SIZE)
502 return -EINVAL;
503
504 return 0;
505}
506
507static int chachapoly_init(struct crypto_aead *tfm)
508{
509 struct aead_instance *inst = aead_alg_instance(tfm);
510 struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst);
511 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
512 struct crypto_skcipher *chacha;
513 struct crypto_ahash *poly;
514 unsigned long align;
515
516 poly = crypto_spawn_ahash(&ictx->poly);
517 if (IS_ERR(poly))
518 return PTR_ERR(poly);
519
520 chacha = crypto_spawn_skcipher(&ictx->chacha);
521 if (IS_ERR(chacha)) {
522 crypto_free_ahash(poly);
523 return PTR_ERR(chacha);
524 }
525
526 ctx->chacha = chacha;
527 ctx->poly = poly;
528 ctx->saltlen = ictx->saltlen;
529
530 align = crypto_aead_alignmask(tfm);
531 align &= ~(crypto_tfm_ctx_alignment() - 1);
532 crypto_aead_set_reqsize(
533 tfm,
534 align + offsetof(struct chachapoly_req_ctx, u) +
535 max(offsetof(struct chacha_req, req) +
536 sizeof(struct skcipher_request) +
537 crypto_skcipher_reqsize(chacha),
538 offsetof(struct poly_req, req) +
539 sizeof(struct ahash_request) +
540 crypto_ahash_reqsize(poly)));
541
542 return 0;
543}
544
545static void chachapoly_exit(struct crypto_aead *tfm)
546{
547 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
548
549 crypto_free_ahash(ctx->poly);
550 crypto_free_skcipher(ctx->chacha);
551}
552
553static void chachapoly_free(struct aead_instance *inst)
554{
555 struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst);
556
557 crypto_drop_skcipher(&ctx->chacha);
558 crypto_drop_ahash(&ctx->poly);
559 kfree(inst);
560}
561
562static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
563 const char *name, unsigned int ivsize)
564{
565 struct crypto_attr_type *algt;
566 struct aead_instance *inst;
567 struct skcipher_alg *chacha;
568 struct crypto_alg *poly;
569 struct hash_alg_common *poly_hash;
570 struct chachapoly_instance_ctx *ctx;
571 const char *chacha_name, *poly_name;
572 int err;
573
574 if (ivsize > CHACHAPOLY_IV_SIZE)
575 return -EINVAL;
576
577 algt = crypto_get_attr_type(tb);
578 if (IS_ERR(algt))
579 return PTR_ERR(algt);
580
581 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
582 return -EINVAL;
583
584 chacha_name = crypto_attr_alg_name(tb[1]);
585 if (IS_ERR(chacha_name))
586 return PTR_ERR(chacha_name);
587 poly_name = crypto_attr_alg_name(tb[2]);
588 if (IS_ERR(poly_name))
589 return PTR_ERR(poly_name);
590
591 poly = crypto_find_alg(poly_name, &crypto_ahash_type,
592 CRYPTO_ALG_TYPE_HASH,
593 CRYPTO_ALG_TYPE_AHASH_MASK |
594 crypto_requires_sync(algt->type,
595 algt->mask));
596 if (IS_ERR(poly))
597 return PTR_ERR(poly);
598 poly_hash = __crypto_hash_alg_common(poly);
599
600 err = -EINVAL;
601 if (poly_hash->digestsize != POLY1305_DIGEST_SIZE)
602 goto out_put_poly;
603
604 err = -ENOMEM;
605 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
606 if (!inst)
607 goto out_put_poly;
608
609 ctx = aead_instance_ctx(inst);
610 ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
611 err = crypto_init_ahash_spawn(&ctx->poly, poly_hash,
612 aead_crypto_instance(inst));
613 if (err)
614 goto err_free_inst;
615
616 crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst));
617 err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0,
618 crypto_requires_sync(algt->type,
619 algt->mask));
620 if (err)
621 goto err_drop_poly;
622
623 chacha = crypto_spawn_skcipher_alg(&ctx->chacha);
624
625 err = -EINVAL;
626 /* Need 16-byte IV size, including Initial Block Counter value */
627 if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE)
628 goto out_drop_chacha;
629 /* Not a stream cipher? */
630 if (chacha->base.cra_blocksize != 1)
631 goto out_drop_chacha;
632
633 err = -ENAMETOOLONG;
634 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
635 "%s(%s,%s)", name, chacha->base.cra_name,
636 poly->cra_name) >= CRYPTO_MAX_ALG_NAME)
637 goto out_drop_chacha;
638 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
639 "%s(%s,%s)", name, chacha->base.cra_driver_name,
640 poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
641 goto out_drop_chacha;
642
643 inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) &
644 CRYPTO_ALG_ASYNC;
645 inst->alg.base.cra_priority = (chacha->base.cra_priority +
646 poly->cra_priority) / 2;
647 inst->alg.base.cra_blocksize = 1;
648 inst->alg.base.cra_alignmask = chacha->base.cra_alignmask |
649 poly->cra_alignmask;
650 inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +
651 ctx->saltlen;
652 inst->alg.ivsize = ivsize;
653 inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha);
654 inst->alg.maxauthsize = POLY1305_DIGEST_SIZE;
655 inst->alg.init = chachapoly_init;
656 inst->alg.exit = chachapoly_exit;
657 inst->alg.encrypt = chachapoly_encrypt;
658 inst->alg.decrypt = chachapoly_decrypt;
659 inst->alg.setkey = chachapoly_setkey;
660 inst->alg.setauthsize = chachapoly_setauthsize;
661
662 inst->free = chachapoly_free;
663
664 err = aead_register_instance(tmpl, inst);
665 if (err)
666 goto out_drop_chacha;
667
668out_put_poly:
669 crypto_mod_put(poly);
670 return err;
671
672out_drop_chacha:
673 crypto_drop_skcipher(&ctx->chacha);
674err_drop_poly:
675 crypto_drop_ahash(&ctx->poly);
676err_free_inst:
677 kfree(inst);
678 goto out_put_poly;
679}
680
681static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
682{
683 return chachapoly_create(tmpl, tb, "rfc7539", 12);
684}
685
686static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
687{
688 return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
689}
690
691static struct crypto_template rfc7539_tmpls[] = {
692 {
693 .name = "rfc7539",
694 .create = rfc7539_create,
695 .module = THIS_MODULE,
696 }, {
697 .name = "rfc7539esp",
698 .create = rfc7539esp_create,
699 .module = THIS_MODULE,
700 },
701};
702
703static int __init chacha20poly1305_module_init(void)
704{
705 return crypto_register_templates(rfc7539_tmpls,
706 ARRAY_SIZE(rfc7539_tmpls));
707}
708
709static void __exit chacha20poly1305_module_exit(void)
710{
711 crypto_unregister_templates(rfc7539_tmpls,
712 ARRAY_SIZE(rfc7539_tmpls));
713}
714
715subsys_initcall(chacha20poly1305_module_init);
716module_exit(chacha20poly1305_module_exit);
717
718MODULE_LICENSE("GPL");
719MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
720MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
721MODULE_ALIAS_CRYPTO("rfc7539");
722MODULE_ALIAS_CRYPTO("rfc7539esp");
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/chacha20.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
27struct chachapoly_instance_ctx {
28 struct crypto_skcipher_spawn chacha;
29 struct crypto_ahash_spawn poly;
30 unsigned int saltlen;
31};
32
33struct 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
41struct 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
53struct chacha_req {
54 u8 iv[CHACHA20_IV_SIZE];
55 struct scatterlist src[1];
56 struct skcipher_request req; /* must be last member */
57};
58
59struct 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
76static 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
86static 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
97static 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
110static 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
120static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
121{
122 async_done_continue(areq->data, err, poly_verify_tag);
123}
124
125static 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
156skip:
157 return poly_verify_tag(req);
158}
159
160static 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
170static void poly_tail_done(struct crypto_async_request *areq, int err)
171{
172 async_done_continue(areq->data, err, poly_tail_continue);
173}
174
175static 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
204static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
205{
206 async_done_continue(areq->data, err, poly_tail);
207}
208
209static 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
234static void poly_cipher_done(struct crypto_async_request *areq, int err)
235{
236 async_done_continue(areq->data, err, poly_cipherpad);
237}
238
239static 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
265static void poly_adpad_done(struct crypto_async_request *areq, int err)
266{
267 async_done_continue(areq->data, err, poly_cipher);
268}
269
270static 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
295static void poly_ad_done(struct crypto_async_request *areq, int err)
296{
297 async_done_continue(areq->data, err, poly_adpad);
298}
299
300static 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
319static void poly_setkey_done(struct crypto_async_request *areq, int err)
320{
321 async_done_continue(areq->data, err, poly_ad);
322}
323
324static 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
346static void poly_init_done(struct crypto_async_request *areq, int err)
347{
348 async_done_continue(areq->data, err, poly_setkey);
349}
350
351static 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
369static void poly_genkey_done(struct crypto_async_request *areq, int err)
370{
371 async_done_continue(areq->data, err, poly_init);
372}
373
374static 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
409static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
410{
411 async_done_continue(areq->data, err, poly_genkey);
412}
413
414static 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
445skip:
446 return poly_genkey(req);
447}
448
449static 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
470static 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
491static 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
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
513static 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
522static 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_skcipher(&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
560static 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
568static 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
577static 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_skcipher(&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) != CHACHA20_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_name,
651 poly_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
683out_put_poly:
684 crypto_mod_put(poly);
685 return err;
686
687out_drop_chacha:
688 crypto_drop_skcipher(&ctx->chacha);
689err_drop_poly:
690 crypto_drop_ahash(&ctx->poly);
691err_free_inst:
692 kfree(inst);
693 goto out_put_poly;
694}
695
696static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
697{
698 return chachapoly_create(tmpl, tb, "rfc7539", 12);
699}
700
701static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
702{
703 return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
704}
705
706static struct crypto_template rfc7539_tmpl = {
707 .name = "rfc7539",
708 .create = rfc7539_create,
709 .module = THIS_MODULE,
710};
711
712static struct crypto_template rfc7539esp_tmpl = {
713 .name = "rfc7539esp",
714 .create = rfc7539esp_create,
715 .module = THIS_MODULE,
716};
717
718static 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
733static void __exit chacha20poly1305_module_exit(void)
734{
735 crypto_unregister_template(&rfc7539esp_tmpl);
736 crypto_unregister_template(&rfc7539_tmpl);
737}
738
739module_init(chacha20poly1305_module_init);
740module_exit(chacha20poly1305_module_exit);
741
742MODULE_LICENSE("GPL");
743MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
744MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
745MODULE_ALIAS_CRYPTO("rfc7539");
746MODULE_ALIAS_CRYPTO("rfc7539esp");