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 struct chachapoly_instance_ctx {
20 	struct crypto_skcipher_spawn chacha;
21 	struct crypto_ahash_spawn poly;
22 	unsigned int saltlen;
23 };
24 
25 struct 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 
33 struct 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 
45 struct chacha_req {
46 	u8 iv[CHACHA_IV_SIZE];
47 	struct scatterlist src[1];
48 	struct skcipher_request req; /* must be last member */
49 };
50 
51 struct 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 
async_done_continue(struct aead_request * req,int err,int (* cont)(struct aead_request *))70 static 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 
chacha_iv(u8 * iv,struct aead_request * req,u32 icb)84 static 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 
poly_verify_tag(struct aead_request * req)95 static 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 
poly_copy_tag(struct aead_request * req)108 static 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 
chacha_decrypt_done(struct crypto_async_request * areq,int err)118 static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
119 {
120 	async_done_continue(areq->data, err, poly_verify_tag);
121 }
122 
chacha_decrypt(struct aead_request * req)123 static 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 
150 skip:
151 	return poly_verify_tag(req);
152 }
153 
poly_tail_continue(struct aead_request * req)154 static 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 
poly_tail_done(struct crypto_async_request * areq,int err)164 static void poly_tail_done(struct crypto_async_request *areq, int err)
165 {
166 	async_done_continue(areq->data, err, poly_tail_continue);
167 }
168 
poly_tail(struct aead_request * req)169 static 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 
poly_cipherpad_done(struct crypto_async_request * areq,int err)194 static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
195 {
196 	async_done_continue(areq->data, err, poly_tail);
197 }
198 
poly_cipherpad(struct aead_request * req)199 static 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 
poly_cipher_done(struct crypto_async_request * areq,int err)223 static void poly_cipher_done(struct crypto_async_request *areq, int err)
224 {
225 	async_done_continue(areq->data, err, poly_cipherpad);
226 }
227 
poly_cipher(struct aead_request * req)228 static 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 
poly_adpad_done(struct crypto_async_request * areq,int err)253 static void poly_adpad_done(struct crypto_async_request *areq, int err)
254 {
255 	async_done_continue(areq->data, err, poly_cipher);
256 }
257 
poly_adpad(struct aead_request * req)258 static 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 
poly_ad_done(struct crypto_async_request * areq,int err)282 static void poly_ad_done(struct crypto_async_request *areq, int err)
283 {
284 	async_done_continue(areq->data, err, poly_adpad);
285 }
286 
poly_ad(struct aead_request * req)287 static 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 
poly_setkey_done(struct crypto_async_request * areq,int err)306 static void poly_setkey_done(struct crypto_async_request *areq, int err)
307 {
308 	async_done_continue(areq->data, err, poly_ad);
309 }
310 
poly_setkey(struct aead_request * req)311 static 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 
poly_init_done(struct crypto_async_request * areq,int err)332 static void poly_init_done(struct crypto_async_request *areq, int err)
333 {
334 	async_done_continue(areq->data, err, poly_setkey);
335 }
336 
poly_init(struct aead_request * req)337 static 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 
poly_genkey_done(struct crypto_async_request * areq,int err)355 static void poly_genkey_done(struct crypto_async_request *areq, int err)
356 {
357 	async_done_continue(areq->data, err, poly_init);
358 }
359 
poly_genkey(struct aead_request * req)360 static 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 
chacha_encrypt_done(struct crypto_async_request * areq,int err)394 static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
395 {
396 	async_done_continue(areq->data, err, poly_genkey);
397 }
398 
chacha_encrypt(struct aead_request * req)399 static 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 
426 skip:
427 	return poly_genkey(req);
428 }
429 
chachapoly_encrypt(struct aead_request * req)430 static 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 
chachapoly_decrypt(struct aead_request * req)452 static 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 
chachapoly_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)474 static 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 
chachapoly_setauthsize(struct crypto_aead * tfm,unsigned int authsize)491 static 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 
chachapoly_init(struct crypto_aead * tfm)500 static 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 
chachapoly_exit(struct crypto_aead * tfm)538 static 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 
chachapoly_free(struct aead_instance * inst)546 static 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 
chachapoly_create(struct crypto_template * tmpl,struct rtattr ** tb,const char * name,unsigned int ivsize)555 static 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) {
631 err_free_inst:
632 		chachapoly_free(inst);
633 	}
634 	return err;
635 }
636 
rfc7539_create(struct crypto_template * tmpl,struct rtattr ** tb)637 static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
638 {
639 	return chachapoly_create(tmpl, tb, "rfc7539", 12);
640 }
641 
rfc7539esp_create(struct crypto_template * tmpl,struct rtattr ** tb)642 static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
643 {
644 	return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
645 }
646 
647 static 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 
chacha20poly1305_module_init(void)659 static int __init chacha20poly1305_module_init(void)
660 {
661 	return crypto_register_templates(rfc7539_tmpls,
662 					 ARRAY_SIZE(rfc7539_tmpls));
663 }
664 
chacha20poly1305_module_exit(void)665 static void __exit chacha20poly1305_module_exit(void)
666 {
667 	crypto_unregister_templates(rfc7539_tmpls,
668 				    ARRAY_SIZE(rfc7539_tmpls));
669 }
670 
671 subsys_initcall(chacha20poly1305_module_init);
672 module_exit(chacha20poly1305_module_exit);
673 
674 MODULE_LICENSE("GPL");
675 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
676 MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
677 MODULE_ALIAS_CRYPTO("rfc7539");
678 MODULE_ALIAS_CRYPTO("rfc7539esp");
679