blob: ed2e12e26dd80b590245bd6008adf8b7de1a5705 [file] [log] [blame]
Martin Willi71ebc4d2015-06-01 13:44:00 +02001/*
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>
Eric Biggers1ca1b912018-11-16 17:26:21 -080016#include <crypto/chacha.h>
Martin Willi2546f812015-07-16 19:14:05 +020017#include <crypto/poly1305.h>
Martin Willi71ebc4d2015-06-01 13:44:00 +020018#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22
23#include "internal.h"
24
Martin Willi71ebc4d2015-06-01 13:44:00 +020025struct chachapoly_instance_ctx {
26 struct crypto_skcipher_spawn chacha;
27 struct crypto_ahash_spawn poly;
28 unsigned int saltlen;
29};
30
31struct chachapoly_ctx {
Herbert Xu1e1f0062016-07-12 13:17:40 +080032 struct crypto_skcipher *chacha;
Martin Willi71ebc4d2015-06-01 13:44:00 +020033 struct crypto_ahash *poly;
34 /* key bytes we use for the ChaCha20 IV */
35 unsigned int saltlen;
36 u8 salt[];
37};
38
39struct poly_req {
40 /* zero byte padding for AD/ciphertext, as needed */
41 u8 pad[POLY1305_BLOCK_SIZE];
42 /* tail data with AD/ciphertext lengths */
43 struct {
44 __le64 assoclen;
45 __le64 cryptlen;
46 } tail;
47 struct scatterlist src[1];
48 struct ahash_request req; /* must be last member */
49};
50
51struct chacha_req {
Eric Biggers1ca1b912018-11-16 17:26:21 -080052 u8 iv[CHACHA_IV_SIZE];
Martin Willi71ebc4d2015-06-01 13:44:00 +020053 struct scatterlist src[1];
Herbert Xu1e1f0062016-07-12 13:17:40 +080054 struct skcipher_request req; /* must be last member */
Martin Willi71ebc4d2015-06-01 13:44:00 +020055};
56
57struct chachapoly_req_ctx {
Herbert Xu74790922015-07-16 12:35:08 +080058 struct scatterlist src[2];
59 struct scatterlist dst[2];
Martin Willic2b7b20a2015-06-16 11:34:16 +020060 /* the key we generate for Poly1305 using Chacha20 */
61 u8 key[POLY1305_KEY_SIZE];
Martin Willi71ebc4d2015-06-01 13:44:00 +020062 /* calculated Poly1305 tag */
63 u8 tag[POLY1305_DIGEST_SIZE];
64 /* length of data to en/decrypt, without ICV */
65 unsigned int cryptlen;
Herbert Xu74790922015-07-16 12:35:08 +080066 /* Actual AD, excluding IV */
67 unsigned int assoclen;
Martin Willi71ebc4d2015-06-01 13:44:00 +020068 union {
69 struct poly_req poly;
70 struct chacha_req chacha;
71 } u;
72};
73
74static inline void async_done_continue(struct aead_request *req, int err,
75 int (*cont)(struct aead_request *))
76{
77 if (!err)
78 err = cont(req);
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,
Eric Biggers1ca1b912018-11-16 17:26:21 -080092 CHACHA_IV_SIZE - sizeof(leicb) - ctx->saltlen);
Martin Willi71ebc4d2015-06-01 13:44:00 +020093}
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
Herbert Xu74790922015-07-16 12:35:08 +0800100 scatterwalk_map_and_copy(tag, req->src,
101 req->assoclen + rctx->cryptlen,
102 sizeof(tag), 0);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200103 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
Herbert Xu74790922015-07-16 12:35:08 +0800112 scatterwalk_map_and_copy(rctx->tag, req->dst,
113 req->assoclen + rctx->cryptlen,
Martin Willi71ebc4d2015-06-01 13:44:00 +0200114 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;
Herbert Xu74790922015-07-16 12:35:08 +0800128 struct scatterlist *src, *dst;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200129 int err;
130
Jason A. Donenfeld161151d2015-12-06 02:51:38 +0100131 if (rctx->cryptlen == 0)
132 goto skip;
133
Martin Willi71ebc4d2015-06-01 13:44:00 +0200134 chacha_iv(creq->iv, req, 1);
135
Herbert Xu74790922015-07-16 12:35:08 +0800136 sg_init_table(rctx->src, 2);
137 src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
138 dst = src;
139
140 if (req->src != req->dst) {
141 sg_init_table(rctx->dst, 2);
142 dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
143 }
144
Herbert Xu1e1f0062016-07-12 13:17:40 +0800145 skcipher_request_set_callback(&creq->req, aead_request_flags(req),
146 chacha_decrypt_done, req);
147 skcipher_request_set_tfm(&creq->req, ctx->chacha);
148 skcipher_request_set_crypt(&creq->req, src, dst,
149 rctx->cryptlen, creq->iv);
150 err = crypto_skcipher_decrypt(&creq->req);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200151 if (err)
152 return err;
153
Jason A. Donenfeld161151d2015-12-06 02:51:38 +0100154skip:
Martin Willi71ebc4d2015-06-01 13:44:00 +0200155 return poly_verify_tag(req);
156}
157
158static int poly_tail_continue(struct aead_request *req)
159{
160 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
161
162 if (rctx->cryptlen == req->cryptlen) /* encrypting */
163 return poly_copy_tag(req);
164
165 return chacha_decrypt(req);
166}
167
168static void poly_tail_done(struct crypto_async_request *areq, int err)
169{
170 async_done_continue(areq->data, err, poly_tail_continue);
171}
172
173static int poly_tail(struct aead_request *req)
174{
Herbert Xu74790922015-07-16 12:35:08 +0800175 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
176 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200177 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
178 struct poly_req *preq = &rctx->u.poly;
179 __le64 len;
180 int err;
181
182 sg_init_table(preq->src, 1);
Herbert Xu74790922015-07-16 12:35:08 +0800183 len = cpu_to_le64(rctx->assoclen);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200184 memcpy(&preq->tail.assoclen, &len, sizeof(len));
185 len = cpu_to_le64(rctx->cryptlen);
186 memcpy(&preq->tail.cryptlen, &len, sizeof(len));
187 sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail));
188
189 ahash_request_set_callback(&preq->req, aead_request_flags(req),
190 poly_tail_done, req);
191 ahash_request_set_tfm(&preq->req, ctx->poly);
192 ahash_request_set_crypt(&preq->req, preq->src,
193 rctx->tag, sizeof(preq->tail));
194
195 err = crypto_ahash_finup(&preq->req);
196 if (err)
197 return err;
198
199 return poly_tail_continue(req);
200}
201
202static void poly_cipherpad_done(struct crypto_async_request *areq, int err)
203{
204 async_done_continue(areq->data, err, poly_tail);
205}
206
207static int poly_cipherpad(struct aead_request *req)
208{
209 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
210 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
211 struct poly_req *preq = &rctx->u.poly;
212 unsigned int padlen, bs = POLY1305_BLOCK_SIZE;
213 int err;
214
215 padlen = (bs - (rctx->cryptlen % bs)) % bs;
216 memset(preq->pad, 0, sizeof(preq->pad));
217 sg_init_table(preq->src, 1);
218 sg_set_buf(preq->src, &preq->pad, padlen);
219
220 ahash_request_set_callback(&preq->req, aead_request_flags(req),
221 poly_cipherpad_done, req);
222 ahash_request_set_tfm(&preq->req, ctx->poly);
223 ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
224
225 err = crypto_ahash_update(&preq->req);
226 if (err)
227 return err;
228
229 return poly_tail(req);
230}
231
232static void poly_cipher_done(struct crypto_async_request *areq, int err)
233{
234 async_done_continue(areq->data, err, poly_cipherpad);
235}
236
237static int poly_cipher(struct aead_request *req)
238{
239 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
240 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
241 struct poly_req *preq = &rctx->u.poly;
242 struct scatterlist *crypt = req->src;
243 int err;
244
245 if (rctx->cryptlen == req->cryptlen) /* encrypting */
246 crypt = req->dst;
247
Herbert Xu74790922015-07-16 12:35:08 +0800248 sg_init_table(rctx->src, 2);
249 crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen);
250
Martin Willi71ebc4d2015-06-01 13:44:00 +0200251 ahash_request_set_callback(&preq->req, aead_request_flags(req),
252 poly_cipher_done, req);
253 ahash_request_set_tfm(&preq->req, ctx->poly);
254 ahash_request_set_crypt(&preq->req, crypt, NULL, rctx->cryptlen);
255
256 err = crypto_ahash_update(&preq->req);
257 if (err)
258 return err;
259
260 return poly_cipherpad(req);
261}
262
263static void poly_adpad_done(struct crypto_async_request *areq, int err)
264{
265 async_done_continue(areq->data, err, poly_cipher);
266}
267
268static int poly_adpad(struct aead_request *req)
269{
270 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
271 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
272 struct poly_req *preq = &rctx->u.poly;
273 unsigned int padlen, bs = POLY1305_BLOCK_SIZE;
274 int err;
275
Herbert Xu74790922015-07-16 12:35:08 +0800276 padlen = (bs - (rctx->assoclen % bs)) % bs;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200277 memset(preq->pad, 0, sizeof(preq->pad));
278 sg_init_table(preq->src, 1);
279 sg_set_buf(preq->src, preq->pad, padlen);
280
281 ahash_request_set_callback(&preq->req, aead_request_flags(req),
282 poly_adpad_done, req);
283 ahash_request_set_tfm(&preq->req, ctx->poly);
284 ahash_request_set_crypt(&preq->req, preq->src, NULL, padlen);
285
286 err = crypto_ahash_update(&preq->req);
287 if (err)
288 return err;
289
290 return poly_cipher(req);
291}
292
293static void poly_ad_done(struct crypto_async_request *areq, int err)
294{
295 async_done_continue(areq->data, err, poly_adpad);
296}
297
298static int poly_ad(struct aead_request *req)
299{
300 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
301 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
302 struct poly_req *preq = &rctx->u.poly;
303 int err;
304
305 ahash_request_set_callback(&preq->req, aead_request_flags(req),
306 poly_ad_done, req);
307 ahash_request_set_tfm(&preq->req, ctx->poly);
Herbert Xu74790922015-07-16 12:35:08 +0800308 ahash_request_set_crypt(&preq->req, req->src, NULL, rctx->assoclen);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200309
310 err = crypto_ahash_update(&preq->req);
311 if (err)
312 return err;
313
314 return poly_adpad(req);
315}
316
Martin Willic2b7b20a2015-06-16 11:34:16 +0200317static void poly_setkey_done(struct crypto_async_request *areq, int err)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200318{
319 async_done_continue(areq->data, err, poly_ad);
320}
321
Martin Willic2b7b20a2015-06-16 11:34:16 +0200322static int poly_setkey(struct aead_request *req)
323{
324 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
325 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
326 struct poly_req *preq = &rctx->u.poly;
327 int err;
328
329 sg_init_table(preq->src, 1);
330 sg_set_buf(preq->src, rctx->key, sizeof(rctx->key));
331
332 ahash_request_set_callback(&preq->req, aead_request_flags(req),
333 poly_setkey_done, req);
334 ahash_request_set_tfm(&preq->req, ctx->poly);
335 ahash_request_set_crypt(&preq->req, preq->src, NULL, sizeof(rctx->key));
336
337 err = crypto_ahash_update(&preq->req);
338 if (err)
339 return err;
340
341 return poly_ad(req);
342}
343
344static void poly_init_done(struct crypto_async_request *areq, int err)
345{
346 async_done_continue(areq->data, err, poly_setkey);
347}
348
Martin Willi71ebc4d2015-06-01 13:44:00 +0200349static int poly_init(struct aead_request *req)
350{
351 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
352 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
353 struct poly_req *preq = &rctx->u.poly;
354 int err;
355
356 ahash_request_set_callback(&preq->req, aead_request_flags(req),
357 poly_init_done, req);
358 ahash_request_set_tfm(&preq->req, ctx->poly);
359
360 err = crypto_ahash_init(&preq->req);
361 if (err)
362 return err;
363
Martin Willic2b7b20a2015-06-16 11:34:16 +0200364 return poly_setkey(req);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200365}
366
367static void poly_genkey_done(struct crypto_async_request *areq, int err)
368{
Martin Willic2b7b20a2015-06-16 11:34:16 +0200369 async_done_continue(areq->data, err, poly_init);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200370}
371
372static int poly_genkey(struct aead_request *req)
373{
Herbert Xu74790922015-07-16 12:35:08 +0800374 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
375 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200376 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
377 struct chacha_req *creq = &rctx->u.chacha;
378 int err;
379
Herbert Xu74790922015-07-16 12:35:08 +0800380 rctx->assoclen = req->assoclen;
381
382 if (crypto_aead_ivsize(tfm) == 8) {
383 if (rctx->assoclen < 8)
384 return -EINVAL;
385 rctx->assoclen -= 8;
386 }
387
Martin Willi71ebc4d2015-06-01 13:44:00 +0200388 sg_init_table(creq->src, 1);
Martin Willic2b7b20a2015-06-16 11:34:16 +0200389 memset(rctx->key, 0, sizeof(rctx->key));
390 sg_set_buf(creq->src, rctx->key, sizeof(rctx->key));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200391
392 chacha_iv(creq->iv, req, 0);
393
Herbert Xu1e1f0062016-07-12 13:17:40 +0800394 skcipher_request_set_callback(&creq->req, aead_request_flags(req),
395 poly_genkey_done, req);
396 skcipher_request_set_tfm(&creq->req, ctx->chacha);
397 skcipher_request_set_crypt(&creq->req, creq->src, creq->src,
398 POLY1305_KEY_SIZE, creq->iv);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200399
Herbert Xu1e1f0062016-07-12 13:17:40 +0800400 err = crypto_skcipher_decrypt(&creq->req);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200401 if (err)
402 return err;
403
Martin Willic2b7b20a2015-06-16 11:34:16 +0200404 return poly_init(req);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200405}
406
407static void chacha_encrypt_done(struct crypto_async_request *areq, int err)
408{
409 async_done_continue(areq->data, err, poly_genkey);
410}
411
412static int chacha_encrypt(struct aead_request *req)
413{
414 struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
415 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
416 struct chacha_req *creq = &rctx->u.chacha;
Herbert Xu74790922015-07-16 12:35:08 +0800417 struct scatterlist *src, *dst;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200418 int err;
419
Jason A. Donenfeld161151d2015-12-06 02:51:38 +0100420 if (req->cryptlen == 0)
421 goto skip;
422
Martin Willi71ebc4d2015-06-01 13:44:00 +0200423 chacha_iv(creq->iv, req, 1);
424
Herbert Xu74790922015-07-16 12:35:08 +0800425 sg_init_table(rctx->src, 2);
426 src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
427 dst = src;
428
429 if (req->src != req->dst) {
430 sg_init_table(rctx->dst, 2);
431 dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);
432 }
433
Herbert Xu1e1f0062016-07-12 13:17:40 +0800434 skcipher_request_set_callback(&creq->req, aead_request_flags(req),
435 chacha_encrypt_done, req);
436 skcipher_request_set_tfm(&creq->req, ctx->chacha);
437 skcipher_request_set_crypt(&creq->req, src, dst,
438 req->cryptlen, creq->iv);
439 err = crypto_skcipher_encrypt(&creq->req);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200440 if (err)
441 return err;
442
Jason A. Donenfeld161151d2015-12-06 02:51:38 +0100443skip:
Martin Willi71ebc4d2015-06-01 13:44:00 +0200444 return poly_genkey(req);
445}
446
447static int chachapoly_encrypt(struct aead_request *req)
448{
449 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
450
451 rctx->cryptlen = req->cryptlen;
452
453 /* encrypt call chain:
454 * - chacha_encrypt/done()
Martin Willic2b7b20a2015-06-16 11:34:16 +0200455 * - poly_genkey/done()
Martin Willi71ebc4d2015-06-01 13:44:00 +0200456 * - poly_init/done()
Martin Willic2b7b20a2015-06-16 11:34:16 +0200457 * - poly_setkey/done()
Martin Willi71ebc4d2015-06-01 13:44:00 +0200458 * - poly_ad/done()
459 * - poly_adpad/done()
460 * - poly_cipher/done()
461 * - poly_cipherpad/done()
462 * - poly_tail/done/continue()
463 * - poly_copy_tag()
464 */
465 return chacha_encrypt(req);
466}
467
468static int chachapoly_decrypt(struct aead_request *req)
469{
470 struct chachapoly_req_ctx *rctx = aead_request_ctx(req);
471
Martin Willi71ebc4d2015-06-01 13:44:00 +0200472 rctx->cryptlen = req->cryptlen - POLY1305_DIGEST_SIZE;
473
474 /* decrypt call chain:
Martin Willic2b7b20a2015-06-16 11:34:16 +0200475 * - poly_genkey/done()
Martin Willi71ebc4d2015-06-01 13:44:00 +0200476 * - poly_init/done()
Martin Willic2b7b20a2015-06-16 11:34:16 +0200477 * - poly_setkey/done()
Martin Willi71ebc4d2015-06-01 13:44:00 +0200478 * - poly_ad/done()
479 * - poly_adpad/done()
480 * - poly_cipher/done()
481 * - poly_cipherpad/done()
482 * - poly_tail/done/continue()
483 * - chacha_decrypt/done()
484 * - poly_verify_tag()
485 */
486 return poly_genkey(req);
487}
488
489static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
490 unsigned int keylen)
491{
492 struct chachapoly_ctx *ctx = crypto_aead_ctx(aead);
493 int err;
494
Eric Biggers1ca1b912018-11-16 17:26:21 -0800495 if (keylen != ctx->saltlen + CHACHA_KEY_SIZE)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200496 return -EINVAL;
497
498 keylen -= ctx->saltlen;
499 memcpy(ctx->salt, key + keylen, ctx->saltlen);
500
Herbert Xu1e1f0062016-07-12 13:17:40 +0800501 crypto_skcipher_clear_flags(ctx->chacha, CRYPTO_TFM_REQ_MASK);
502 crypto_skcipher_set_flags(ctx->chacha, crypto_aead_get_flags(aead) &
503 CRYPTO_TFM_REQ_MASK);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200504
Herbert Xu1e1f0062016-07-12 13:17:40 +0800505 err = crypto_skcipher_setkey(ctx->chacha, key, keylen);
506 crypto_aead_set_flags(aead, crypto_skcipher_get_flags(ctx->chacha) &
507 CRYPTO_TFM_RES_MASK);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200508 return err;
509}
510
511static int chachapoly_setauthsize(struct crypto_aead *tfm,
512 unsigned int authsize)
513{
514 if (authsize != POLY1305_DIGEST_SIZE)
515 return -EINVAL;
516
517 return 0;
518}
519
Herbert Xu74790922015-07-16 12:35:08 +0800520static int chachapoly_init(struct crypto_aead *tfm)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200521{
Herbert Xu74790922015-07-16 12:35:08 +0800522 struct aead_instance *inst = aead_alg_instance(tfm);
523 struct chachapoly_instance_ctx *ictx = aead_instance_ctx(inst);
524 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
Herbert Xu1e1f0062016-07-12 13:17:40 +0800525 struct crypto_skcipher *chacha;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200526 struct crypto_ahash *poly;
527 unsigned long align;
528
529 poly = crypto_spawn_ahash(&ictx->poly);
530 if (IS_ERR(poly))
531 return PTR_ERR(poly);
532
Eric Biggers60425a82016-10-28 09:52:19 -0700533 chacha = crypto_spawn_skcipher(&ictx->chacha);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200534 if (IS_ERR(chacha)) {
535 crypto_free_ahash(poly);
536 return PTR_ERR(chacha);
537 }
538
539 ctx->chacha = chacha;
540 ctx->poly = poly;
541 ctx->saltlen = ictx->saltlen;
542
Herbert Xu74790922015-07-16 12:35:08 +0800543 align = crypto_aead_alignmask(tfm);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200544 align &= ~(crypto_tfm_ctx_alignment() - 1);
Herbert Xu74790922015-07-16 12:35:08 +0800545 crypto_aead_set_reqsize(
546 tfm,
547 align + offsetof(struct chachapoly_req_ctx, u) +
548 max(offsetof(struct chacha_req, req) +
Herbert Xu1e1f0062016-07-12 13:17:40 +0800549 sizeof(struct skcipher_request) +
550 crypto_skcipher_reqsize(chacha),
Herbert Xu74790922015-07-16 12:35:08 +0800551 offsetof(struct poly_req, req) +
552 sizeof(struct ahash_request) +
553 crypto_ahash_reqsize(poly)));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200554
555 return 0;
556}
557
Herbert Xu74790922015-07-16 12:35:08 +0800558static void chachapoly_exit(struct crypto_aead *tfm)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200559{
Herbert Xu74790922015-07-16 12:35:08 +0800560 struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200561
562 crypto_free_ahash(ctx->poly);
Herbert Xu1e1f0062016-07-12 13:17:40 +0800563 crypto_free_skcipher(ctx->chacha);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200564}
565
Herbert Xu74790922015-07-16 12:35:08 +0800566static void chachapoly_free(struct aead_instance *inst)
567{
568 struct chachapoly_instance_ctx *ctx = aead_instance_ctx(inst);
569
570 crypto_drop_skcipher(&ctx->chacha);
571 crypto_drop_ahash(&ctx->poly);
572 kfree(inst);
573}
574
575static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
576 const char *name, unsigned int ivsize)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200577{
578 struct crypto_attr_type *algt;
Herbert Xu74790922015-07-16 12:35:08 +0800579 struct aead_instance *inst;
Herbert Xu1e1f0062016-07-12 13:17:40 +0800580 struct skcipher_alg *chacha;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200581 struct crypto_alg *poly;
Herbert Xu74790922015-07-16 12:35:08 +0800582 struct hash_alg_common *poly_hash;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200583 struct chachapoly_instance_ctx *ctx;
584 const char *chacha_name, *poly_name;
585 int err;
586
587 if (ivsize > CHACHAPOLY_IV_SIZE)
Herbert Xu74790922015-07-16 12:35:08 +0800588 return -EINVAL;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200589
590 algt = crypto_get_attr_type(tb);
591 if (IS_ERR(algt))
Herbert Xu74790922015-07-16 12:35:08 +0800592 return PTR_ERR(algt);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200593
Herbert Xu5e4b8c12015-08-13 17:29:06 +0800594 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
Herbert Xu74790922015-07-16 12:35:08 +0800595 return -EINVAL;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200596
597 chacha_name = crypto_attr_alg_name(tb[1]);
598 if (IS_ERR(chacha_name))
Herbert Xu74790922015-07-16 12:35:08 +0800599 return PTR_ERR(chacha_name);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200600 poly_name = crypto_attr_alg_name(tb[2]);
601 if (IS_ERR(poly_name))
Herbert Xu74790922015-07-16 12:35:08 +0800602 return PTR_ERR(poly_name);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200603
604 poly = crypto_find_alg(poly_name, &crypto_ahash_type,
605 CRYPTO_ALG_TYPE_HASH,
Herbert Xu1e1f0062016-07-12 13:17:40 +0800606 CRYPTO_ALG_TYPE_AHASH_MASK |
607 crypto_requires_sync(algt->type,
608 algt->mask));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200609 if (IS_ERR(poly))
Herbert Xu74790922015-07-16 12:35:08 +0800610 return PTR_ERR(poly);
Eric Biggerse57121d2017-12-11 12:15:17 -0800611 poly_hash = __crypto_hash_alg_common(poly);
612
613 err = -EINVAL;
614 if (poly_hash->digestsize != POLY1305_DIGEST_SIZE)
615 goto out_put_poly;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200616
617 err = -ENOMEM;
618 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
619 if (!inst)
620 goto out_put_poly;
621
Herbert Xu74790922015-07-16 12:35:08 +0800622 ctx = aead_instance_ctx(inst);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200623 ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
Herbert Xu74790922015-07-16 12:35:08 +0800624 err = crypto_init_ahash_spawn(&ctx->poly, poly_hash,
625 aead_crypto_instance(inst));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200626 if (err)
627 goto err_free_inst;
628
Herbert Xu74790922015-07-16 12:35:08 +0800629 crypto_set_skcipher_spawn(&ctx->chacha, aead_crypto_instance(inst));
Eric Biggersa35528e2016-10-28 09:51:13 -0700630 err = crypto_grab_skcipher(&ctx->chacha, chacha_name, 0,
631 crypto_requires_sync(algt->type,
632 algt->mask));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200633 if (err)
634 goto err_drop_poly;
635
Herbert Xu1e1f0062016-07-12 13:17:40 +0800636 chacha = crypto_spawn_skcipher_alg(&ctx->chacha);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200637
638 err = -EINVAL;
639 /* Need 16-byte IV size, including Initial Block Counter value */
Eric Biggers1ca1b912018-11-16 17:26:21 -0800640 if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200641 goto out_drop_chacha;
642 /* Not a stream cipher? */
Herbert Xu1e1f0062016-07-12 13:17:40 +0800643 if (chacha->base.cra_blocksize != 1)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200644 goto out_drop_chacha;
645
646 err = -ENAMETOOLONG;
Herbert Xu74790922015-07-16 12:35:08 +0800647 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
Martin Willi71ebc4d2015-06-01 13:44:00 +0200648 "%s(%s,%s)", name, chacha_name,
649 poly_name) >= CRYPTO_MAX_ALG_NAME)
650 goto out_drop_chacha;
Herbert Xu74790922015-07-16 12:35:08 +0800651 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
Herbert Xu1e1f0062016-07-12 13:17:40 +0800652 "%s(%s,%s)", name, chacha->base.cra_driver_name,
Martin Willi71ebc4d2015-06-01 13:44:00 +0200653 poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
654 goto out_drop_chacha;
655
Herbert Xu1e1f0062016-07-12 13:17:40 +0800656 inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) &
Herbert Xu74790922015-07-16 12:35:08 +0800657 CRYPTO_ALG_ASYNC;
Herbert Xu1e1f0062016-07-12 13:17:40 +0800658 inst->alg.base.cra_priority = (chacha->base.cra_priority +
Herbert Xu74790922015-07-16 12:35:08 +0800659 poly->cra_priority) / 2;
660 inst->alg.base.cra_blocksize = 1;
Herbert Xu1e1f0062016-07-12 13:17:40 +0800661 inst->alg.base.cra_alignmask = chacha->base.cra_alignmask |
Herbert Xu74790922015-07-16 12:35:08 +0800662 poly->cra_alignmask;
663 inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +
664 ctx->saltlen;
665 inst->alg.ivsize = ivsize;
Herbert Xu1e1f0062016-07-12 13:17:40 +0800666 inst->alg.chunksize = crypto_skcipher_alg_chunksize(chacha);
Herbert Xu74790922015-07-16 12:35:08 +0800667 inst->alg.maxauthsize = POLY1305_DIGEST_SIZE;
668 inst->alg.init = chachapoly_init;
669 inst->alg.exit = chachapoly_exit;
670 inst->alg.encrypt = chachapoly_encrypt;
671 inst->alg.decrypt = chachapoly_decrypt;
672 inst->alg.setkey = chachapoly_setkey;
673 inst->alg.setauthsize = chachapoly_setauthsize;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200674
Herbert Xu74790922015-07-16 12:35:08 +0800675 inst->free = chachapoly_free;
676
677 err = aead_register_instance(tmpl, inst);
678 if (err)
679 goto out_drop_chacha;
680
681out_put_poly:
Martin Willi71ebc4d2015-06-01 13:44:00 +0200682 crypto_mod_put(poly);
Herbert Xu74790922015-07-16 12:35:08 +0800683 return err;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200684
685out_drop_chacha:
686 crypto_drop_skcipher(&ctx->chacha);
687err_drop_poly:
688 crypto_drop_ahash(&ctx->poly);
689err_free_inst:
690 kfree(inst);
Herbert Xu74790922015-07-16 12:35:08 +0800691 goto out_put_poly;
Martin Willi71ebc4d2015-06-01 13:44:00 +0200692}
693
Herbert Xu74790922015-07-16 12:35:08 +0800694static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)
Martin Willi71ebc4d2015-06-01 13:44:00 +0200695{
Herbert Xu74790922015-07-16 12:35:08 +0800696 return chachapoly_create(tmpl, tb, "rfc7539", 12);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200697}
698
Herbert Xu74790922015-07-16 12:35:08 +0800699static int rfc7539esp_create(struct crypto_template *tmpl, struct rtattr **tb)
Martin Willi4db4ad22015-06-01 13:44:02 +0200700{
Herbert Xu74790922015-07-16 12:35:08 +0800701 return chachapoly_create(tmpl, tb, "rfc7539esp", 8);
Martin Willi71ebc4d2015-06-01 13:44:00 +0200702}
703
Xiongfeng Wang1a5e02b2019-01-18 13:58:15 +0800704static struct crypto_template rfc7539_tmpls[] = {
705 {
706 .name = "rfc7539",
707 .create = rfc7539_create,
708 .module = THIS_MODULE,
709 }, {
710 .name = "rfc7539esp",
711 .create = rfc7539esp_create,
712 .module = THIS_MODULE,
713 },
Martin Willi4db4ad22015-06-01 13:44:02 +0200714};
715
Martin Willi71ebc4d2015-06-01 13:44:00 +0200716static int __init chacha20poly1305_module_init(void)
717{
Xiongfeng Wang1a5e02b2019-01-18 13:58:15 +0800718 return crypto_register_templates(rfc7539_tmpls,
719 ARRAY_SIZE(rfc7539_tmpls));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200720}
721
722static void __exit chacha20poly1305_module_exit(void)
723{
Xiongfeng Wang1a5e02b2019-01-18 13:58:15 +0800724 crypto_unregister_templates(rfc7539_tmpls,
725 ARRAY_SIZE(rfc7539_tmpls));
Martin Willi71ebc4d2015-06-01 13:44:00 +0200726}
727
728module_init(chacha20poly1305_module_init);
729module_exit(chacha20poly1305_module_exit);
730
731MODULE_LICENSE("GPL");
732MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
733MODULE_DESCRIPTION("ChaCha20-Poly1305 AEAD");
Martin Willi71ebc4d2015-06-01 13:44:00 +0200734MODULE_ALIAS_CRYPTO("rfc7539");
Martin Willi4db4ad22015-06-01 13:44:02 +0200735MODULE_ALIAS_CRYPTO("rfc7539esp");