xref: /openbmc/linux/crypto/chacha20poly1305.c (revision d3597236)
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 <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 
21 #include "internal.h"
22 
23 #define POLY1305_BLOCK_SIZE	16
24 #define POLY1305_DIGEST_SIZE	16
25 #define POLY1305_KEY_SIZE	32
26 #define CHACHA20_KEY_SIZE	32
27 #define CHACHA20_IV_SIZE	16
28 #define CHACHAPOLY_IV_SIZE	12
29 
30 struct chachapoly_instance_ctx {
31 	struct crypto_skcipher_spawn chacha;
32 	struct crypto_ahash_spawn poly;
33 	unsigned int saltlen;
34 };
35 
36 struct chachapoly_ctx {
37 	struct crypto_ablkcipher *chacha;
38 	struct crypto_ahash *poly;
39 	/* key bytes we use for the ChaCha20 IV */
40 	unsigned int saltlen;
41 	u8 salt[];
42 };
43 
44 struct poly_req {
45 	/* zero byte padding for AD/ciphertext, as needed */
46 	u8 pad[POLY1305_BLOCK_SIZE];
47 	/* tail data with AD/ciphertext lengths */
48 	struct {
49 		__le64 assoclen;
50 		__le64 cryptlen;
51 	} tail;
52 	struct scatterlist src[1];
53 	struct ahash_request req; /* must be last member */
54 };
55 
56 struct chacha_req {
57 	u8 iv[CHACHA20_IV_SIZE];
58 	struct scatterlist src[1];
59 	struct ablkcipher_request req; /* must be last member */
60 };
61 
62 struct chachapoly_req_ctx {
63 	/* the key we generate for Poly1305 using Chacha20 */
64 	u8 key[POLY1305_KEY_SIZE];
65 	/* calculated Poly1305 tag */
66 	u8 tag[POLY1305_DIGEST_SIZE];
67 	/* length of data to en/decrypt, without ICV */
68 	unsigned int cryptlen;
69 	union {
70 		struct poly_req poly;
71 		struct chacha_req chacha;
72 	} u;
73 };
74 
75 static inline void async_done_continue(struct aead_request *req, int err,
76 				       int (*cont)(struct aead_request *))
77 {
78 	if (!err)
79 		err = cont(req);
80 
81 	if (err != -EINPROGRESS && err != -EBUSY)
82 		aead_request_complete(req, err);
83 }
84 
85 static void chacha_iv(u8 *iv, struct aead_request *req, u32 icb)
86 {
87 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
88 	__le32 leicb = cpu_to_le32(icb);
89 
90 	memcpy(iv, &leicb, sizeof(leicb));
91 	memcpy(iv + sizeof(leicb), ctx->salt, ctx->saltlen);
92 	memcpy(iv + sizeof(leicb) + ctx->saltlen, req->iv,
93 	       CHACHA20_IV_SIZE - sizeof(leicb) - ctx->saltlen);
94 }
95 
96 static int poly_verify_tag(struct aead_request *req)
97 {
98 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
99 	u8 tag[sizeof(rctx->tag)];
100 
101 	scatterwalk_map_and_copy(tag, req->src, rctx->cryptlen, sizeof(tag), 0);
102 	if (crypto_memneq(tag, rctx->tag, sizeof(tag)))
103 		return -EBADMSG;
104 	return 0;
105 }
106 
107 static int poly_copy_tag(struct aead_request *req)
108 {
109 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
110 
111 	scatterwalk_map_and_copy(rctx->tag, req->dst, rctx->cryptlen,
112 				 sizeof(rctx->tag), 1);
113 	return 0;
114 }
115 
116 static void chacha_decrypt_done(struct crypto_async_request *areq, int err)
117 {
118 	async_done_continue(areq->data, err, poly_verify_tag);
119 }
120 
121 static int chacha_decrypt(struct aead_request *req)
122 {
123 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
124 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
125 	struct chacha_req *creq = &rctx->u.chacha;
126 	int err;
127 
128 	chacha_iv(creq->iv, req, 1);
129 
130 	ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
131 					chacha_decrypt_done, req);
132 	ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
133 	ablkcipher_request_set_crypt(&creq->req, req->src, req->dst,
134 				     rctx->cryptlen, creq->iv);
135 	err = crypto_ablkcipher_decrypt(&creq->req);
136 	if (err)
137 		return err;
138 
139 	return poly_verify_tag(req);
140 }
141 
142 static int poly_tail_continue(struct aead_request *req)
143 {
144 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
145 
146 	if (rctx->cryptlen == req->cryptlen) /* encrypting */
147 		return poly_copy_tag(req);
148 
149 	return chacha_decrypt(req);
150 }
151 
152 static void poly_tail_done(struct crypto_async_request *areq, int err)
153 {
154 	async_done_continue(areq->data, err, poly_tail_continue);
155 }
156 
157 static int poly_tail(struct aead_request *req)
158 {
159 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
160 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
161 	struct poly_req *preq = &rctx->u.poly;
162 	__le64 len;
163 	int err;
164 
165 	sg_init_table(preq->src, 1);
166 	len = cpu_to_le64(req->assoclen);
167 	memcpy(&preq->tail.assoclen, &len, sizeof(len));
168 	len = cpu_to_le64(rctx->cryptlen);
169 	memcpy(&preq->tail.cryptlen, &len, sizeof(len));
170 	sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail));
171 
172 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
173 				   poly_tail_done, req);
174 	ahash_request_set_tfm(&preq->req, ctx->poly);
175 	ahash_request_set_crypt(&preq->req, preq->src,
176 				rctx->tag, sizeof(preq->tail));
177 
178 	err = crypto_ahash_finup(&preq->req);
179 	if (err)
180 		return err;
181 
182 	return poly_tail_continue(req);
183 }
184 
185 static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
186 {
187 	async_done_continue(areq->data, err, poly_tail);
188 }
189 
190 static int poly_cipherpad(struct aead_request *req)
191 {
192 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
193 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
194 	struct poly_req *preq = &rctx->u.poly;
195 	unsigned int padlen, bs = POLY1305_BLOCK_SIZE;
196 	int err;
197 
198 	padlen = (bs - (rctx->cryptlen % bs)) % bs;
199 	memset(preq->pad, 0, sizeof(preq->pad));
200 	sg_init_table(preq->src, 1);
201 	sg_set_buf(preq->src, &preq->pad, padlen);
202 
203 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
204 				   poly_cipherpad_done, req);
205 	ahash_request_set_tfm(&preq->req, ctx->poly);
206 	ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
207 
208 	err = crypto_ahash_update(&preq->req);
209 	if (err)
210 		return err;
211 
212 	return poly_tail(req);
213 }
214 
215 static void poly_cipher_done(struct crypto_async_request *areq, int err)
216 {
217 	async_done_continue(areq->data, err, poly_cipherpad);
218 }
219 
220 static int poly_cipher(struct aead_request *req)
221 {
222 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
223 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
224 	struct poly_req *preq = &rctx->u.poly;
225 	struct scatterlist *crypt = req->src;
226 	int err;
227 
228 	if (rctx->cryptlen == req->cryptlen) /* encrypting */
229 		crypt = req->dst;
230 
231 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
232 				   poly_cipher_done, req);
233 	ahash_request_set_tfm(&preq->req, ctx->poly);
234 	ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);
235 
236 	err = crypto_ahash_update(&preq->req);
237 	if (err)
238 		return err;
239 
240 	return poly_cipherpad(req);
241 }
242 
243 static void poly_adpad_done(struct crypto_async_request *areq, int err)
244 {
245 	async_done_continue(areq->data, err, poly_cipher);
246 }
247 
248 static int poly_adpad(struct aead_request *req)
249 {
250 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
251 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
252 	struct poly_req *preq = &rctx->u.poly;
253 	unsigned int padlen, bs = POLY1305_BLOCK_SIZE;
254 	int err;
255 
256 	padlen = (bs - (req->assoclen % bs)) % bs;
257 	memset(preq->pad, 0, sizeof(preq->pad));
258 	sg_init_table(preq->src, 1);
259 	sg_set_buf(preq->src, preq->pad, padlen);
260 
261 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
262 				   poly_adpad_done, req);
263 	ahash_request_set_tfm(&preq->req, ctx->poly);
264 	ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
265 
266 	err = crypto_ahash_update(&preq->req);
267 	if (err)
268 		return err;
269 
270 	return poly_cipher(req);
271 }
272 
273 static void poly_ad_done(struct crypto_async_request *areq, int err)
274 {
275 	async_done_continue(areq->data, err, poly_adpad);
276 }
277 
278 static int poly_ad(struct aead_request *req)
279 {
280 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
281 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
282 	struct poly_req *preq = &rctx->u.poly;
283 	int err;
284 
285 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
286 				   poly_ad_done, req);
287 	ahash_request_set_tfm(&preq->req, ctx->poly);
288 	ahash_request_set_crypt(&preq->req, req->assoc, NULL, req->assoclen);
289 
290 	err = crypto_ahash_update(&preq->req);
291 	if (err)
292 		return err;
293 
294 	return poly_adpad(req);
295 }
296 
297 static void poly_setkey_done(struct crypto_async_request *areq, int err)
298 {
299 	async_done_continue(areq->data, err, poly_ad);
300 }
301 
302 static int poly_setkey(struct aead_request *req)
303 {
304 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
305 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
306 	struct poly_req *preq = &rctx->u.poly;
307 	int err;
308 
309 	sg_init_table(preq->src, 1);
310 	sg_set_buf(preq->src, rctx->key, sizeof(rctx->key));
311 
312 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
313 				   poly_setkey_done, req);
314 	ahash_request_set_tfm(&preq->req, ctx->poly);
315 	ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));
316 
317 	err = crypto_ahash_update(&preq->req);
318 	if (err)
319 		return err;
320 
321 	return poly_ad(req);
322 }
323 
324 static void poly_init_done(struct crypto_async_request *areq, int err)
325 {
326 	async_done_continue(areq->data, err, poly_setkey);
327 }
328 
329 static int poly_init(struct aead_request *req)
330 {
331 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
332 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
333 	struct poly_req *preq = &rctx->u.poly;
334 	int err;
335 
336 	ahash_request_set_callback(&preq->req, aead_request_flags(req),
337 				   poly_init_done, req);
338 	ahash_request_set_tfm(&preq->req, ctx->poly);
339 
340 	err = crypto_ahash_init(&preq->req);
341 	if (err)
342 		return err;
343 
344 	return poly_setkey(req);
345 }
346 
347 static void poly_genkey_done(struct crypto_async_request *areq, int err)
348 {
349 	async_done_continue(areq->data, err, poly_init);
350 }
351 
352 static int poly_genkey(struct aead_request *req)
353 {
354 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
355 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
356 	struct chacha_req *creq = &rctx->u.chacha;
357 	int err;
358 
359 	sg_init_table(creq->src, 1);
360 	memset(rctx->key, 0, sizeof(rctx->key));
361 	sg_set_buf(creq->src, rctx->key, sizeof(rctx->key));
362 
363 	chacha_iv(creq->iv, req, 0);
364 
365 	ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
366 					poly_genkey_done, req);
367 	ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
368 	ablkcipher_request_set_crypt(&creq->req, creq->src, creq->src,
369 				     POLY1305_KEY_SIZE, creq->iv);
370 
371 	err = crypto_ablkcipher_decrypt(&creq->req);
372 	if (err)
373 		return err;
374 
375 	return poly_init(req);
376 }
377 
378 static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
379 {
380 	async_done_continue(areq->data, err, poly_genkey);
381 }
382 
383 static int chacha_encrypt(struct aead_request *req)
384 {
385 	struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
386 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
387 	struct chacha_req *creq = &rctx->u.chacha;
388 	int err;
389 
390 	chacha_iv(creq->iv, req, 1);
391 
392 	ablkcipher_request_set_callback(&creq->req, aead_request_flags(req),
393 					chacha_encrypt_done, req);
394 	ablkcipher_request_set_tfm(&creq->req, ctx->chacha);
395 	ablkcipher_request_set_crypt(&creq->req, req->src, req->dst,
396 				     req->cryptlen, creq->iv);
397 	err = crypto_ablkcipher_encrypt(&creq->req);
398 	if (err)
399 		return err;
400 
401 	return poly_genkey(req);
402 }
403 
404 static int chachapoly_encrypt(struct aead_request *req)
405 {
406 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
407 
408 	rctx->cryptlen = req->cryptlen;
409 
410 	/* encrypt call chain:
411 	 * - chacha_encrypt/done()
412 	 * - poly_genkey/done()
413 	 * - poly_init/done()
414 	 * - poly_setkey/done()
415 	 * - poly_ad/done()
416 	 * - poly_adpad/done()
417 	 * - poly_cipher/done()
418 	 * - poly_cipherpad/done()
419 	 * - poly_tail/done/continue()
420 	 * - poly_copy_tag()
421 	 */
422 	return chacha_encrypt(req);
423 }
424 
425 static int chachapoly_decrypt(struct aead_request *req)
426 {
427 	struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
428 
429 	if (req->cryptlen < POLY1305_DIGEST_SIZE)
430 		return -EINVAL;
431 	rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
432 
433 	/* decrypt call chain:
434 	 * - poly_genkey/done()
435 	 * - poly_init/done()
436 	 * - poly_setkey/done()
437 	 * - poly_ad/done()
438 	 * - poly_adpad/done()
439 	 * - poly_cipher/done()
440 	 * - poly_cipherpad/done()
441 	 * - poly_tail/done/continue()
442 	 * - chacha_decrypt/done()
443 	 * - poly_verify_tag()
444 	 */
445 	return poly_genkey(req);
446 }
447 
448 static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
449 			     unsigned int keylen)
450 {
451 	struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
452 	int err;
453 
454 	if (keylen != ctx->saltlen + CHACHA20_KEY_SIZE)
455 		return -EINVAL;
456 
457 	keylen -= ctx->saltlen;
458 	memcpy(ctx->salt, key + keylen, ctx->saltlen);
459 
460 	crypto_ablkcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
461 	crypto_ablkcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
462 				    CRYPTO_TFM_REQ_MASK);
463 
464 	err = crypto_ablkcipher_setkey(ctx->chacha, key, keylen);
465 	crypto_aead_set_flags(aead, crypto_ablkcipher_get_flags(ctx->chacha) &
466 			      CRYPTO_TFM_RES_MASK);
467 	return err;
468 }
469 
470 static int chachapoly_setauthsize(struct crypto_aead *tfm,
471 				  unsigned int authsize)
472 {
473 	if (authsize != POLY1305_DIGEST_SIZE)
474 		return -EINVAL;
475 
476 	return 0;
477 }
478 
479 static int chachapoly_init(struct crypto_tfm *tfm)
480 {
481 	struct crypto_instance *inst = (void *)tfm->__crt_alg;
482 	struct chachapoly_instance_ctx *ictx = crypto_instance_ctx(inst);
483 	struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm);
484 	struct crypto_ablkcipher *chacha;
485 	struct crypto_ahash *poly;
486 	unsigned long align;
487 
488 	poly = crypto_spawn_ahash(&ictx->poly);
489 	if (IS_ERR(poly))
490 		return PTR_ERR(poly);
491 
492 	chacha = crypto_spawn_skcipher(&ictx->chacha);
493 	if (IS_ERR(chacha)) {
494 		crypto_free_ahash(poly);
495 		return PTR_ERR(chacha);
496 	}
497 
498 	ctx->chacha = chacha;
499 	ctx->poly = poly;
500 	ctx->saltlen = ictx->saltlen;
501 
502 	align = crypto_tfm_alg_alignmask(tfm);
503 	align &= ~(crypto_tfm_ctx_alignment() - 1);
504 	crypto_aead_set_reqsize(__crypto_aead_cast(tfm),
505 				align + offsetof(struct chachapoly_req_ctx, u) +
506 				max(offsetof(struct chacha_req, req) +
507 				    sizeof(struct ablkcipher_request) +
508 				    crypto_ablkcipher_reqsize(chacha),
509 				    offsetof(struct poly_req, req) +
510 				    sizeof(struct ahash_request) +
511 				    crypto_ahash_reqsize(poly)));
512 
513 	return 0;
514 }
515 
516 static void chachapoly_exit(struct crypto_tfm *tfm)
517 {
518 	struct chachapoly_ctx *ctx = crypto_tfm_ctx(tfm);
519 
520 	crypto_free_ahash(ctx->poly);
521 	crypto_free_ablkcipher(ctx->chacha);
522 }
523 
524 static struct crypto_instance *chachapoly_alloc(struct rtattr **tb,
525 						const char *name,
526 						unsigned int ivsize)
527 {
528 	struct crypto_attr_type *algt;
529 	struct crypto_instance *inst;
530 	struct crypto_alg *chacha;
531 	struct crypto_alg *poly;
532 	struct ahash_alg *poly_ahash;
533 	struct chachapoly_instance_ctx *ctx;
534 	const char *chacha_name, *poly_name;
535 	int err;
536 
537 	if (ivsize > CHACHAPOLY_IV_SIZE)
538 		return ERR_PTR(-EINVAL);
539 
540 	algt = crypto_get_attr_type(tb);
541 	if (IS_ERR(algt))
542 		return ERR_CAST(algt);
543 
544 	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
545 		return ERR_PTR(-EINVAL);
546 
547 	chacha_name = crypto_attr_alg_name(tb[1]);
548 	if (IS_ERR(chacha_name))
549 		return ERR_CAST(chacha_name);
550 	poly_name = crypto_attr_alg_name(tb[2]);
551 	if (IS_ERR(poly_name))
552 		return ERR_CAST(poly_name);
553 
554 	poly = crypto_find_alg(poly_name, &crypto_ahash_type,
555 			       CRYPTO_ALG_TYPE_HASH,
556 			       CRYPTO_ALG_TYPE_AHASH_MASK);
557 	if (IS_ERR(poly))
558 		return ERR_CAST(poly);
559 
560 	err = -ENOMEM;
561 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
562 	if (!inst)
563 		goto out_put_poly;
564 
565 	ctx = crypto_instance_ctx(inst);
566 	ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
567 	poly_ahash = container_of(poly, struct ahash_alg, halg.base);
568 	err = crypto_init_ahash_spawn(&ctx->poly, &poly_ahash->halg, inst);
569 	if (err)
570 		goto err_free_inst;
571 
572 	crypto_set_skcipher_spawn(&ctx->chacha, inst);
573 	err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0,
574 				   crypto_requires_sync(algt->type,
575 							algt->mask));
576 	if (err)
577 		goto err_drop_poly;
578 
579 	chacha = crypto_skcipher_spawn_alg(&ctx->chacha);
580 
581 	err = -EINVAL;
582 	/* Need 16-byte IV size, including Initial Block Counter value */
583 	if (chacha->cra_ablkcipher.ivsize != CHACHA20_IV_SIZE)
584 		goto out_drop_chacha;
585 	/* Not a stream cipher? */
586 	if (chacha->cra_blocksize != 1)
587 		goto out_drop_chacha;
588 
589 	err = -ENAMETOOLONG;
590 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
591 		     "%s(%s,%s)", name, chacha_name,
592 		     poly_name) >= CRYPTO_MAX_ALG_NAME)
593 		goto out_drop_chacha;
594 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
595 		     "%s(%s,%s)", name, chacha->cra_driver_name,
596 		     poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
597 		goto out_drop_chacha;
598 
599 	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD;
600 	inst->alg.cra_flags |= (chacha->cra_flags |
601 				poly->cra_flags) & CRYPTO_ALG_ASYNC;
602 	inst->alg.cra_priority = (chacha->cra_priority +
603 				  poly->cra_priority) / 2;
604 	inst->alg.cra_blocksize = 1;
605 	inst->alg.cra_alignmask = chacha->cra_alignmask | poly->cra_alignmask;
606 	inst->alg.cra_type = &crypto_nivaead_type;
607 	inst->alg.cra_aead.ivsize = ivsize;
608 	inst->alg.cra_aead.maxauthsize = POLY1305_DIGEST_SIZE;
609 	inst->alg.cra_ctxsize = sizeof(struct chachapoly_ctx) + ctx->saltlen;
610 	inst->alg.cra_init = chachapoly_init;
611 	inst->alg.cra_exit = chachapoly_exit;
612 	inst->alg.cra_aead.encrypt = chachapoly_encrypt;
613 	inst->alg.cra_aead.decrypt = chachapoly_decrypt;
614 	inst->alg.cra_aead.setkey = chachapoly_setkey;
615 	inst->alg.cra_aead.setauthsize = chachapoly_setauthsize;
616 	inst->alg.cra_aead.geniv = "seqiv";
617 
618 out:
619 	crypto_mod_put(poly);
620 	return inst;
621 
622 out_drop_chacha:
623 	crypto_drop_skcipher(&ctx->chacha);
624 err_drop_poly:
625 	crypto_drop_ahash(&ctx->poly);
626 err_free_inst:
627 	kfree(inst);
628 out_put_poly:
629 	inst = ERR_PTR(err);
630 	goto out;
631 }
632 
633 static struct crypto_instance *rfc7539_alloc(struct rtattr **tb)
634 {
635 	return chachapoly_alloc(tb, "rfc7539", 12);
636 }
637 
638 static struct crypto_instance *rfc7539esp_alloc(struct rtattr **tb)
639 {
640 	return chachapoly_alloc(tb, "rfc7539esp", 8);
641 }
642 
643 static void chachapoly_free(struct crypto_instance *inst)
644 {
645 	struct chachapoly_instance_ctx *ctx = crypto_instance_ctx(inst);
646 
647 	crypto_drop_skcipher(&ctx->chacha);
648 	crypto_drop_ahash(&ctx->poly);
649 	kfree(inst);
650 }
651 
652 static struct crypto_template rfc7539_tmpl = {
653 	.name = "rfc7539",
654 	.alloc = rfc7539_alloc,
655 	.free = chachapoly_free,
656 	.module = THIS_MODULE,
657 };
658 
659 static struct crypto_template rfc7539esp_tmpl = {
660 	.name = "rfc7539esp",
661 	.alloc = rfc7539esp_alloc,
662 	.free = chachapoly_free,
663 	.module = THIS_MODULE,
664 };
665 
666 static int __init chacha20poly1305_module_init(void)
667 {
668 	int err;
669 
670 	err = crypto_register_template(&rfc7539_tmpl);
671 	if (err)
672 		return err;
673 
674 	err = crypto_register_template(&rfc7539esp_tmpl);
675 	if (err)
676 		crypto_unregister_template(&rfc7539_tmpl);
677 
678 	return err;
679 }
680 
681 static void __exit chacha20poly1305_module_exit(void)
682 {
683 	crypto_unregister_template(&rfc7539esp_tmpl);
684 	crypto_unregister_template(&rfc7539_tmpl);
685 }
686 
687 module_init(chacha20poly1305_module_init);
688 module_exit(chacha20poly1305_module_exit);
689 
690 MODULE_LICENSE("GPL");
691 MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
692 MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
693 MODULE_ALIAS_CRYPTO("chacha20poly1305");
694 MODULE_ALIAS_CRYPTO("rfc7539");
695 MODULE_ALIAS_CRYPTO("rfc7539esp");
696