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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
19struct chachapoly_instance_ctx {
20 struct crypto_skcipher_spawn chacha;
21 struct crypto_ahash_spawn poly;
22 unsigned int saltlen;
23};
24
25struct chachapoly_ctx {
26 struct crypto_skcipher *chacha;
27 struct crypto_ahash *poly;
28 /* key bytes we use for the ChaCha20 IV */
29 unsigned int saltlen;
30 u8 salt[];
31};
32
33struct poly_req {
34 /* zero byte padding for AD/ciphertext, as needed */
35 u8 pad[POLY1305_BLOCK_SIZE];
36 /* tail data with AD/ciphertext lengths */
37 struct {
38 __le64 assoclen;
39 __le64 cryptlen;
40 } tail;
41 struct scatterlist src[1];
42 struct ahash_request req; /* must be last member */
43};
44
45struct chacha_req {
46 u8 iv[CHACHA_IV_SIZE];
47 struct scatterlist src[1];
48 struct skcipher_request req; /* must be last member */
49};
50
51struct chachapoly_req_ctx {
52 struct scatterlist src[2];
53 struct scatterlist dst[2];
54 /* the key we generate for Poly1305 using Chacha20 */
55 u8 key[POLY1305_KEY_SIZE];
56 /* calculated Poly1305 tag */
57 u8 tag[POLY1305_DIGEST_SIZE];
58 /* length of data to en/decrypt, without ICV */
59 unsigned int cryptlen;
60 /* Actual AD, excluding IV */
61 unsigned int assoclen;
62 /* request flags, with MAY_SLEEP cleared if needed */
63 u32 flags;
64 union {
65 struct poly_req poly;
66 struct chacha_req chacha;
67 } u;
68};
69
70static inline void async_done_continue(struct aead_request *req, int err,
71 int (*cont)(struct aead_request *))
72{
73 if (!err) {
74 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
75
76 rctx->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
77 err = cont(req);
78 }
79
80 if (err != -EINPROGRESS && err != -EBUSY)
81 aead_request_complete(req, err);
82}
83
84static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb)
85{
86 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
87 __le32 leicb = cpu_to_le32(icb);
88
89 memcpy(iv, &leicb, sizeof(leicb));
90 memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen);
91 memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv,
92 CHACHA_IV_SIZE - sizeof(leicb) - ctx->saltlen);
93}
94
95static int poly_verify_tag(struct aead_request *req)
96{
97 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
98 u8 tag[sizeof(rctx->tag)];
99
100 scatterwalk_map_and_copy(tag, req->src,
101 req->assoclen + rctx->cryptlen,
102 sizeof(tag), 0);
103 if (crypto_memneq(tag, rctx->tag, sizeof(tag)))
104 return -EBADMSG;
105 return 0;
106}
107
108static int poly_copy_tag(struct aead_request *req)
109{
110 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
111
112 scatterwalk_map_and_copy(rctx->tag, req->dst,
113 req->assoclen + rctx->cryptlen,
114 sizeof(rctx->tag), 1);
115 return 0;
116}
117
118static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
119{
120 async_done_continue(areq->data, err, poly_verify_tag);
121}
122
123static int chacha_decrypt(struct aead_request *req)
124{
125 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
126 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
127 struct chacha_req *creq = &rctx->u.chacha;
128 struct scatterlist *src, *dst;
129 int err;
130
131 if (rctx->cryptlen == 0)
132 goto skip;
133
134 chacha_iv(creq->iv, req, 1);
135
136 src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
137 dst = src;
138 if (req->src != req->dst)
139 dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
140
141 skcipher_request_set_callback(&creq->req, rctx->flags,
142 chacha_decrypt_done, req);
143 skcipher_request_set_tfm(&creq->req, ctx->chacha);
144 skcipher_request_set_crypt(&creq->req, src, dst,
145 rctx->cryptlen, creq->iv);
146 err = crypto_skcipher_decrypt(&creq->req);
147 if (err)
148 return err;
149
150skip:
151 return poly_verify_tag(req);
152}
153
154static int poly_tail_continue(struct aead_request *req)
155{
156 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
157
158 if (rctx->cryptlen == req->cryptlen) /* encrypting */
159 return poly_copy_tag(req);
160
161 return chacha_decrypt(req);
162}
163
164static void poly_tail_done(struct crypto_async_request *areq, int err)
165{
166 async_done_continue(areq->data, err, poly_tail_continue);
167}
168
169static int poly_tail(struct aead_request *req)
170{
171 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
172 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
173 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
174 struct poly_req *preq = &rctx->u.poly;
175 int err;
176
177 preq->tail.assoclen = cpu_to_le64(rctx->assoclen);
178 preq->tail.cryptlen = cpu_to_le64(rctx->cryptlen);
179 sg_init_one(preq->src, &preq->tail, sizeof(preq->tail));
180
181 ahash_request_set_callback(&preq->req, rctx->flags,
182 poly_tail_done, req);
183 ahash_request_set_tfm(&preq->req, ctx->poly);
184 ahash_request_set_crypt(&preq->req, preq->src,
185 rctx->tag, sizeof(preq->tail));
186
187 err = crypto_ahash_finup(&preq->req);
188 if (err)
189 return err;
190
191 return poly_tail_continue(req);
192}
193
194static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
195{
196 async_done_continue(areq->data, err, poly_tail);
197}
198
199static int poly_cipherpad(struct aead_request *req)
200{
201 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
202 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
203 struct poly_req *preq = &rctx->u.poly;
204 unsigned int padlen;
205 int err;
206
207 padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE;
208 memset(preq->pad, 0, sizeof(preq->pad));
209 sg_init_one(preq->src, preq->pad, padlen);
210
211 ahash_request_set_callback(&preq->req, rctx->flags,
212 poly_cipherpad_done, req);
213 ahash_request_set_tfm(&preq->req, ctx->poly);
214 ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
215
216 err = crypto_ahash_update(&preq->req);
217 if (err)
218 return err;
219
220 return poly_tail(req);
221}
222
223static void poly_cipher_done(struct crypto_async_request *areq, int err)
224{
225 async_done_continue(areq->data, err, poly_cipherpad);
226}
227
228static int poly_cipher(struct aead_request *req)
229{
230 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
231 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
232 struct poly_req *preq = &rctx->u.poly;
233 struct scatterlist *crypt = req->src;
234 int err;
235
236 if (rctx->cryptlen == req->cryptlen) /* encrypting */
237 crypt = req->dst;
238
239 crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen);
240
241 ahash_request_set_callback(&preq->req, rctx->flags,
242 poly_cipher_done, req);
243 ahash_request_set_tfm(&preq->req, ctx->poly);
244 ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);
245
246 err = crypto_ahash_update(&preq->req);
247 if (err)
248 return err;
249
250 return poly_cipherpad(req);
251}
252
253static void poly_adpad_done(struct crypto_async_request *areq, int err)
254{
255 async_done_continue(areq->data, err, poly_cipher);
256}
257
258static int poly_adpad(struct aead_request *req)
259{
260 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
261 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
262 struct poly_req *preq = &rctx->u.poly;
263 unsigned int padlen;
264 int err;
265
266 padlen = -rctx->assoclen % POLY1305_BLOCK_SIZE;
267 memset(preq->pad, 0, sizeof(preq->pad));
268 sg_init_one(preq->src, preq->pad, padlen);
269
270 ahash_request_set_callback(&preq->req, rctx->flags,
271 poly_adpad_done, req);
272 ahash_request_set_tfm(&preq->req, ctx->poly);
273 ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
274
275 err = crypto_ahash_update(&preq->req);
276 if (err)
277 return err;
278
279 return poly_cipher(req);
280}
281
282static void poly_ad_done(struct crypto_async_request *areq, int err)
283{
284 async_done_continue(areq->data, err, poly_adpad);
285}
286
287static int poly_ad(struct aead_request *req)
288{
289 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
290 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
291 struct poly_req *preq = &rctx->u.poly;
292 int err;
293
294 ahash_request_set_callback(&preq->req, rctx->flags,
295 poly_ad_done, req);
296 ahash_request_set_tfm(&preq->req, ctx->poly);
297 ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen);
298
299 err = crypto_ahash_update(&preq->req);
300 if (err)
301 return err;
302
303 return poly_adpad(req);
304}
305
306static void poly_setkey_done(struct crypto_async_request *areq, int err)
307{
308 async_done_continue(areq->data, err, poly_ad);
309}
310
311static int poly_setkey(struct aead_request *req)
312{
313 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
314 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
315 struct poly_req *preq = &rctx->u.poly;
316 int err;
317
318 sg_init_one(preq->src, rctx->key, sizeof(rctx->key));
319
320 ahash_request_set_callback(&preq->req, rctx->flags,
321 poly_setkey_done, req);
322 ahash_request_set_tfm(&preq->req, ctx->poly);
323 ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));
324
325 err = crypto_ahash_update(&preq->req);
326 if (err)
327 return err;
328
329 return poly_ad(req);
330}
331
332static void poly_init_done(struct crypto_async_request *areq, int err)
333{
334 async_done_continue(areq->data, err, poly_setkey);
335}
336
337static int poly_init(struct aead_request *req)
338{
339 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
340 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
341 struct poly_req *preq = &rctx->u.poly;
342 int err;
343
344 ahash_request_set_callback(&preq->req, rctx->flags,
345 poly_init_done, req);
346 ahash_request_set_tfm(&preq->req, ctx->poly);
347
348 err = crypto_ahash_init(&preq->req);
349 if (err)
350 return err;
351
352 return poly_setkey(req);
353}
354
355static void poly_genkey_done(struct crypto_async_request *areq, int err)
356{
357 async_done_continue(areq->data, err, poly_init);
358}
359
360static int poly_genkey(struct aead_request *req)
361{
362 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
363 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
364 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
365 struct chacha_req *creq = &rctx->u.chacha;
366 int err;
367
368 rctx->assoclen = req->assoclen;
369
370 if (crypto_aead_ivsize(tfm) == 8) {
371 if (rctx->assoclen < 8)
372 return -EINVAL;
373 rctx->assoclen -= 8;
374 }
375
376 memset(rctx->key, 0, sizeof(rctx->key));
377 sg_init_one(creq->src, rctx->key, sizeof(rctx->key));
378
379 chacha_iv(creq->iv, req, 0);
380
381 skcipher_request_set_callback(&creq->req, rctx->flags,
382 poly_genkey_done, req);
383 skcipher_request_set_tfm(&creq->req, ctx->chacha);
384 skcipher_request_set_crypt(&creq->req, creq->src, creq->src,
385 POLY1305_KEY_SIZE, creq->iv);
386
387 err = crypto_skcipher_decrypt(&creq->req);
388 if (err)
389 return err;
390
391 return poly_init(req);
392}
393
394static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
395{
396 async_done_continue(areq->data, err, poly_genkey);
397}
398
399static int chacha_encrypt(struct aead_request *req)
400{
401 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
402 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
403 struct chacha_req *creq = &rctx->u.chacha;
404 struct scatterlist *src, *dst;
405 int err;
406
407 if (req->cryptlen == 0)
408 goto skip;
409
410 chacha_iv(creq->iv, req, 1);
411
412 src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
413 dst = src;
414 if (req->src != req->dst)
415 dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
416
417 skcipher_request_set_callback(&creq->req, rctx->flags,
418 chacha_encrypt_done, req);
419 skcipher_request_set_tfm(&creq->req, ctx->chacha);
420 skcipher_request_set_crypt(&creq->req, src, dst,
421 req->cryptlen, creq->iv);
422 err = crypto_skcipher_encrypt(&creq->req);
423 if (err)
424 return err;
425
426skip:
427 return poly_genkey(req);
428}
429
430static int chachapoly_encrypt(struct aead_request *req)
431{
432 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
433
434 rctx->cryptlen = req->cryptlen;
435 rctx->flags = aead_request_flags(req);
436
437 /* encrypt call chain:
438 * - chacha_encrypt/done()
439 * - poly_genkey/done()
440 * - poly_init/done()
441 * - poly_setkey/done()
442 * - poly_ad/done()
443 * - poly_adpad/done()
444 * - poly_cipher/done()
445 * - poly_cipherpad/done()
446 * - poly_tail/done/continue()
447 * - poly_copy_tag()
448 */
449 return chacha_encrypt(req);
450}
451
452static int chachapoly_decrypt(struct aead_request *req)
453{
454 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
455
456 rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
457 rctx->flags = aead_request_flags(req);
458
459 /* decrypt call chain:
460 * - poly_genkey/done()
461 * - poly_init/done()
462 * - poly_setkey/done()
463 * - poly_ad/done()
464 * - poly_adpad/done()
465 * - poly_cipher/done()
466 * - poly_cipherpad/done()
467 * - poly_tail/done/continue()
468 * - chacha_decrypt/done()
469 * - poly_verify_tag()
470 */
471 return poly_genkey(req);
472}
473
474static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
475 unsigned int keylen)
476{
477 struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
478
479 if (keylen != ctx->saltlen + CHACHA_KEY_SIZE)
480 return -EINVAL;
481
482 keylen -= ctx->saltlen;
483 memcpy(ctx->salt, key + keylen, ctx->saltlen);
484
485 crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
486 crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
487 CRYPTO_TFM_REQ_MASK);
488 return crypto_skcipher_setkey(ctx->chacha, key, keylen);
489}
490
491static int chachapoly_setauthsize(struct crypto_aead *tfm,
492 unsigned int authsize)
493{
494 if (authsize != POLY1305_DIGEST_SIZE)
495 return -EINVAL;
496
497 return 0;
498}
499
500static int chachapoly_init(struct crypto_aead *tfm)
501{
502 struct aead_instance *inst = aead_alg_instance(tfm);
503 struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst);
504 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
505 struct crypto_skcipher *chacha;
506 struct crypto_ahash *poly;
507 unsigned long align;
508
509 poly = crypto_spawn_ahash(&ictx->poly);
510 if (IS_ERR(poly))
511 return PTR_ERR(poly);
512
513 chacha = crypto_spawn_skcipher(&ictx->chacha);
514 if (IS_ERR(chacha)) {
515 crypto_free_ahash(poly);
516 return PTR_ERR(chacha);
517 }
518
519 ctx->chacha = chacha;
520 ctx->poly = poly;
521 ctx->saltlen = ictx->saltlen;
522
523 align = crypto_aead_alignmask(tfm);
524 align &= ~(crypto_tfm_ctx_alignment() - 1);
525 crypto_aead_set_reqsize(
526 tfm,
527 align + offsetof(struct chachapoly_req_ctx, u) +
528 max(offsetof(struct chacha_req, req) +
529 sizeof(struct skcipher_request) +
530 crypto_skcipher_reqsize(chacha),
531 offsetof(struct poly_req, req) +
532 sizeof(struct ahash_request) +
533 crypto_ahash_reqsize(poly)));
534
535 return 0;
536}
537
538static void chachapoly_exit(struct crypto_aead *tfm)
539{
540 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
541
542 crypto_free_ahash(ctx->poly);
543 crypto_free_skcipher(ctx->chacha);
544}
545
546static void chachapoly_free(struct aead_instance *inst)
547{
548 struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst);
549
550 crypto_drop_skcipher(&ctx->chacha);
551 crypto_drop_ahash(&ctx->poly);
552 kfree(inst);
553}
554
555static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
556 const char *name, unsigned int ivsize)
557{
558 u32 mask;
559 struct aead_instance *inst;
560 struct chachapoly_instance_ctx *ctx;
561 struct skcipher_alg *chacha;
562 struct hash_alg_common *poly;
563 int err;
564
565 if (ivsize > CHACHAPOLY_IV_SIZE)
566 return -EINVAL;
567
568 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD, &mask);
569 if (err)
570 return err;
571
572 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
573 if (!inst)
574 return -ENOMEM;
575 ctx = aead_instance_ctx(inst);
576 ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
577
578 err = crypto_grab_skcipher(&ctx->chacha, aead_crypto_instance(inst),
579 crypto_attr_alg_name(tb[1]), 0, mask);
580 if (err)
581 goto err_free_inst;
582 chacha = crypto_spawn_skcipher_alg(&ctx->chacha);
583
584 err = crypto_grab_ahash(&ctx->poly, aead_crypto_instance(inst),
585 crypto_attr_alg_name(tb[2]), 0, mask);
586 if (err)
587 goto err_free_inst;
588 poly = crypto_spawn_ahash_alg(&ctx->poly);
589
590 err = -EINVAL;
591 if (poly->digestsize != POLY1305_DIGEST_SIZE)
592 goto err_free_inst;
593 /* Need 16-byte IV size, including Initial Block Counter value */
594 if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE)
595 goto err_free_inst;
596 /* Not a stream cipher? */
597 if (chacha->base.cra_blocksize != 1)
598 goto err_free_inst;
599
600 err = -ENAMETOOLONG;
601 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
602 "%s(%s,%s)", name, chacha->base.cra_name,
603 poly->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
604 goto err_free_inst;
605 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
606 "%s(%s,%s)", name, chacha->base.cra_driver_name,
607 poly->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
608 goto err_free_inst;
609
610 inst->alg.base.cra_priority = (chacha->base.cra_priority +
611 poly->base.cra_priority) / 2;
612 inst->alg.base.cra_blocksize = 1;
613 inst->alg.base.cra_alignmask = chacha->base.cra_alignmask |
614 poly->base.cra_alignmask;
615 inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +
616 ctx->saltlen;
617 inst->alg.ivsize = ivsize;
618 inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha);
619 inst->alg.maxauthsize = POLY1305_DIGEST_SIZE;
620 inst->alg.init = chachapoly_init;
621 inst->alg.exit = chachapoly_exit;
622 inst->alg.encrypt = chachapoly_encrypt;
623 inst->alg.decrypt = chachapoly_decrypt;
624 inst->alg.setkey = chachapoly_setkey;
625 inst->alg.setauthsize = chachapoly_setauthsize;
626
627 inst->free = chachapoly_free;
628
629 err = aead_register_instance(tmpl, inst);
630 if (err) {
631err_free_inst:
632 chachapoly_free(inst);
633 }
634 return err;
635}
636
637static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
638{
639 return chachapoly_create(tmpl, tb, "rfc7539", 12);
640}
641
642static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
643{
644 return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
645}
646
647static struct crypto_template rfc7539_tmpls[] = {
648 {
649 .name = "rfc7539",
650 .create = rfc7539_create,
651 .module = THIS_MODULE,
652 }, {
653 .name = "rfc7539esp",
654 .create = rfc7539esp_create,
655 .module = THIS_MODULE,
656 },
657};
658
659static int __init chacha20poly1305_module_init(void)
660{
661 return crypto_register_templates(rfc7539_tmpls,
662 ARRAY_SIZE(rfc7539_tmpls));
663}
664
665static void __exit chacha20poly1305_module_exit(void)
666{
667 crypto_unregister_templates(rfc7539_tmpls,
668 ARRAY_SIZE(rfc7539_tmpls));
669}
670
671subsys_initcall(chacha20poly1305_module_init);
672module_exit(chacha20poly1305_module_exit);
673
674MODULE_LICENSE("GPL");
675MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
676MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
677MODULE_ALIAS_CRYPTO("rfc7539");
678MODULE_ALIAS_CRYPTO("rfc7539esp");
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");