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
21 struct chachapoly_instance_ctx {
22 struct crypto_skcipher_spawn chacha;
23 struct crypto_ahash_spawn poly;
24 unsigned int saltlen;
25 };
26
27 struct 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
35 struct 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
47 struct chacha_req {
48 u8 iv[CHACHA_IV_SIZE];
49 struct scatterlist src[1];
50 struct skcipher_request req; /* must be last member */
51 };
52
53 struct 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
async_done_continue(struct aead_request * req,int err,int (* cont)(struct aead_request *))72 static 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
chacha_iv(u8 * iv,struct aead_request * req,u32 icb)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 CHACHA_IV_SIZE - sizeof(leicb) - ctx->saltlen);
95 }
96
poly_verify_tag(struct aead_request * req)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
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
poly_copy_tag(struct aead_request * req)110 static 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
chacha_decrypt_done(struct crypto_async_request * areq,int err)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
chacha_decrypt(struct aead_request * req)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;
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
152 skip:
153 return poly_verify_tag(req);
154 }
155
poly_tail_continue(struct aead_request * req)156 static 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
poly_tail_done(struct crypto_async_request * areq,int err)166 static void poly_tail_done(struct crypto_async_request *areq, int err)
167 {
168 async_done_continue(areq->data, err, poly_tail_continue);
169 }
170
poly_tail(struct aead_request * req)171 static 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
poly_cipherpad_done(struct crypto_async_request * areq,int err)196 static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
197 {
198 async_done_continue(areq->data, err, poly_tail);
199 }
200
poly_cipherpad(struct aead_request * req)201 static 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
poly_cipher_done(struct crypto_async_request * areq,int err)225 static void poly_cipher_done(struct crypto_async_request *areq, int err)
226 {
227 async_done_continue(areq->data, err, poly_cipherpad);
228 }
229
poly_cipher(struct aead_request * req)230 static 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
poly_adpad_done(struct crypto_async_request * areq,int err)255 static void poly_adpad_done(struct crypto_async_request *areq, int err)
256 {
257 async_done_continue(areq->data, err, poly_cipher);
258 }
259
poly_adpad(struct aead_request * req)260 static 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
poly_ad_done(struct crypto_async_request * areq,int err)284 static void poly_ad_done(struct crypto_async_request *areq, int err)
285 {
286 async_done_continue(areq->data, err, poly_adpad);
287 }
288
poly_ad(struct aead_request * req)289 static 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
poly_setkey_done(struct crypto_async_request * areq,int err)308 static void poly_setkey_done(struct crypto_async_request *areq, int err)
309 {
310 async_done_continue(areq->data, err, poly_ad);
311 }
312
poly_setkey(struct aead_request * req)313 static 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
poly_init_done(struct crypto_async_request * areq,int err)334 static void poly_init_done(struct crypto_async_request *areq, int err)
335 {
336 async_done_continue(areq->data, err, poly_setkey);
337 }
338
poly_init(struct aead_request * req)339 static 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
poly_genkey_done(struct crypto_async_request * areq,int err)357 static void poly_genkey_done(struct crypto_async_request *areq, int err)
358 {
359 async_done_continue(areq->data, err, poly_init);
360 }
361
poly_genkey(struct aead_request * req)362 static 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
chacha_encrypt_done(struct crypto_async_request * areq,int err)396 static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
397 {
398 async_done_continue(areq->data, err, poly_genkey);
399 }
400
chacha_encrypt(struct aead_request * req)401 static 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
428 skip:
429 return poly_genkey(req);
430 }
431
chachapoly_encrypt(struct aead_request * req)432 static 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
chachapoly_decrypt(struct aead_request * req)454 static 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
chachapoly_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)476 static 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
chachapoly_setauthsize(struct crypto_aead * tfm,unsigned int authsize)498 static 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
chachapoly_init(struct crypto_aead * tfm)507 static 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
chachapoly_exit(struct crypto_aead * tfm)545 static 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
chachapoly_free(struct aead_instance * inst)553 static 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
chachapoly_create(struct crypto_template * tmpl,struct rtattr ** tb,const char * name,unsigned int ivsize)562 static 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
668 out_put_poly:
669 crypto_mod_put(poly);
670 return err;
671
672 out_drop_chacha:
673 crypto_drop_skcipher(&ctx->chacha);
674 err_drop_poly:
675 crypto_drop_ahash(&ctx->poly);
676 err_free_inst:
677 kfree(inst);
678 goto out_put_poly;
679 }
680
rfc7539_create(struct crypto_template * tmpl,struct rtattr ** tb)681 static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
682 {
683 return chachapoly_create(tmpl, tb, "rfc7539", 12);
684 }
685
rfc7539esp_create(struct crypto_template * tmpl,struct rtattr ** tb)686 static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
687 {
688 return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
689 }
690
691 static 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
chacha20poly1305_module_init(void)703 static int __init chacha20poly1305_module_init(void)
704 {
705 return crypto_register_templates(rfc7539_tmpls,
706 ARRAY_SIZE(rfc7539_tmpls));
707 }
708
chacha20poly1305_module_exit(void)709 static void __exit chacha20poly1305_module_exit(void)
710 {
711 crypto_unregister_templates(rfc7539_tmpls,
712 ARRAY_SIZE(rfc7539_tmpls));
713 }
714
715 subsys_initcall(chacha20poly1305_module_init);
716 module_exit(chacha20poly1305_module_exit);
717
718 MODULE_LICENSE("GPL");
719 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
720 MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
721 MODULE_ALIAS_CRYPTO("rfc7539");
722 MODULE_ALIAS_CRYPTO("rfc7539esp");
723