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400c40cf SM |
1 | /* |
2 | * algif_aead: User-space interface for AEAD algorithms | |
3 | * | |
4 | * Copyright (C) 2014, Stephan Mueller <smueller@chronox.de> | |
5 | * | |
6 | * This file provides the user-space API for AEAD ciphers. | |
7 | * | |
8 | * This file is derived from algif_skcipher.c. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify it | |
11 | * under the terms of the GNU General Public License as published by the Free | |
12 | * Software Foundation; either version 2 of the License, or (at your option) | |
13 | * any later version. | |
14 | */ | |
15 | ||
83094e5e | 16 | #include <crypto/internal/aead.h> |
400c40cf SM |
17 | #include <crypto/scatterwalk.h> |
18 | #include <crypto/if_alg.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/net.h> | |
25 | #include <net/sock.h> | |
26 | ||
27 | struct aead_sg_list { | |
28 | unsigned int cur; | |
29 | struct scatterlist sg[ALG_MAX_PAGES]; | |
30 | }; | |
31 | ||
83094e5e TS |
32 | struct aead_async_rsgl { |
33 | struct af_alg_sgl sgl; | |
34 | struct list_head list; | |
35 | }; | |
36 | ||
37 | struct aead_async_req { | |
38 | struct scatterlist *tsgl; | |
39 | struct aead_async_rsgl first_rsgl; | |
40 | struct list_head list; | |
41 | struct kiocb *iocb; | |
42 | unsigned int tsgls; | |
43 | char iv[]; | |
44 | }; | |
45 | ||
400c40cf SM |
46 | struct aead_ctx { |
47 | struct aead_sg_list tsgl; | |
83094e5e TS |
48 | struct aead_async_rsgl first_rsgl; |
49 | struct list_head list; | |
400c40cf SM |
50 | |
51 | void *iv; | |
52 | ||
53 | struct af_alg_completion completion; | |
54 | ||
55 | unsigned long used; | |
56 | ||
57 | unsigned int len; | |
58 | bool more; | |
59 | bool merge; | |
60 | bool enc; | |
61 | ||
62 | size_t aead_assoclen; | |
63 | struct aead_request aead_req; | |
64 | }; | |
65 | ||
66 | static inline int aead_sndbuf(struct sock *sk) | |
67 | { | |
68 | struct alg_sock *ask = alg_sk(sk); | |
69 | struct aead_ctx *ctx = ask->private; | |
70 | ||
71 | return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) - | |
72 | ctx->used, 0); | |
73 | } | |
74 | ||
75 | static inline bool aead_writable(struct sock *sk) | |
76 | { | |
77 | return PAGE_SIZE <= aead_sndbuf(sk); | |
78 | } | |
79 | ||
80 | static inline bool aead_sufficient_data(struct aead_ctx *ctx) | |
81 | { | |
82 | unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req)); | |
83 | ||
0c1e16cd SM |
84 | /* |
85 | * The minimum amount of memory needed for an AEAD cipher is | |
86 | * the AAD and in case of decryption the tag. | |
87 | */ | |
88 | return ctx->used >= ctx->aead_assoclen + (ctx->enc ? 0 : as); | |
400c40cf SM |
89 | } |
90 | ||
83094e5e TS |
91 | static void aead_reset_ctx(struct aead_ctx *ctx) |
92 | { | |
93 | struct aead_sg_list *sgl = &ctx->tsgl; | |
94 | ||
95 | sg_init_table(sgl->sg, ALG_MAX_PAGES); | |
96 | sgl->cur = 0; | |
97 | ctx->used = 0; | |
98 | ctx->more = 0; | |
99 | ctx->merge = 0; | |
100 | } | |
101 | ||
400c40cf SM |
102 | static void aead_put_sgl(struct sock *sk) |
103 | { | |
104 | struct alg_sock *ask = alg_sk(sk); | |
105 | struct aead_ctx *ctx = ask->private; | |
106 | struct aead_sg_list *sgl = &ctx->tsgl; | |
107 | struct scatterlist *sg = sgl->sg; | |
108 | unsigned int i; | |
109 | ||
110 | for (i = 0; i < sgl->cur; i++) { | |
111 | if (!sg_page(sg + i)) | |
112 | continue; | |
113 | ||
114 | put_page(sg_page(sg + i)); | |
115 | sg_assign_page(sg + i, NULL); | |
116 | } | |
83094e5e | 117 | aead_reset_ctx(ctx); |
400c40cf SM |
118 | } |
119 | ||
120 | static void aead_wmem_wakeup(struct sock *sk) | |
121 | { | |
122 | struct socket_wq *wq; | |
123 | ||
124 | if (!aead_writable(sk)) | |
125 | return; | |
126 | ||
127 | rcu_read_lock(); | |
128 | wq = rcu_dereference(sk->sk_wq); | |
1ce0bf50 | 129 | if (skwq_has_sleeper(wq)) |
400c40cf SM |
130 | wake_up_interruptible_sync_poll(&wq->wait, POLLIN | |
131 | POLLRDNORM | | |
132 | POLLRDBAND); | |
133 | sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); | |
134 | rcu_read_unlock(); | |
135 | } | |
136 | ||
137 | static int aead_wait_for_data(struct sock *sk, unsigned flags) | |
138 | { | |
d9dc8b0f | 139 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
400c40cf SM |
140 | struct alg_sock *ask = alg_sk(sk); |
141 | struct aead_ctx *ctx = ask->private; | |
142 | long timeout; | |
400c40cf SM |
143 | int err = -ERESTARTSYS; |
144 | ||
145 | if (flags & MSG_DONTWAIT) | |
146 | return -EAGAIN; | |
147 | ||
9cd3e072 | 148 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
d9dc8b0f | 149 | add_wait_queue(sk_sleep(sk), &wait); |
400c40cf SM |
150 | for (;;) { |
151 | if (signal_pending(current)) | |
152 | break; | |
400c40cf | 153 | timeout = MAX_SCHEDULE_TIMEOUT; |
d9dc8b0f | 154 | if (sk_wait_event(sk, &timeout, !ctx->more, &wait)) { |
400c40cf SM |
155 | err = 0; |
156 | break; | |
157 | } | |
158 | } | |
d9dc8b0f | 159 | remove_wait_queue(sk_sleep(sk), &wait); |
400c40cf | 160 | |
9cd3e072 | 161 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
400c40cf SM |
162 | |
163 | return err; | |
164 | } | |
165 | ||
166 | static void aead_data_wakeup(struct sock *sk) | |
167 | { | |
168 | struct alg_sock *ask = alg_sk(sk); | |
169 | struct aead_ctx *ctx = ask->private; | |
170 | struct socket_wq *wq; | |
171 | ||
172 | if (ctx->more) | |
173 | return; | |
174 | if (!ctx->used) | |
175 | return; | |
176 | ||
177 | rcu_read_lock(); | |
178 | wq = rcu_dereference(sk->sk_wq); | |
1ce0bf50 | 179 | if (skwq_has_sleeper(wq)) |
400c40cf SM |
180 | wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | |
181 | POLLRDNORM | | |
182 | POLLRDBAND); | |
183 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); | |
184 | rcu_read_unlock(); | |
185 | } | |
186 | ||
eccd02f3 | 187 | static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) |
400c40cf SM |
188 | { |
189 | struct sock *sk = sock->sk; | |
190 | struct alg_sock *ask = alg_sk(sk); | |
191 | struct aead_ctx *ctx = ask->private; | |
192 | unsigned ivsize = | |
193 | crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req)); | |
194 | struct aead_sg_list *sgl = &ctx->tsgl; | |
195 | struct af_alg_control con = {}; | |
196 | long copied = 0; | |
197 | bool enc = 0; | |
198 | bool init = 0; | |
199 | int err = -EINVAL; | |
200 | ||
201 | if (msg->msg_controllen) { | |
202 | err = af_alg_cmsg_send(msg, &con); | |
203 | if (err) | |
204 | return err; | |
205 | ||
206 | init = 1; | |
207 | switch (con.op) { | |
208 | case ALG_OP_ENCRYPT: | |
209 | enc = 1; | |
210 | break; | |
211 | case ALG_OP_DECRYPT: | |
212 | enc = 0; | |
213 | break; | |
214 | default: | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
218 | if (con.iv && con.iv->ivlen != ivsize) | |
219 | return -EINVAL; | |
220 | } | |
221 | ||
222 | lock_sock(sk); | |
223 | if (!ctx->more && ctx->used) | |
224 | goto unlock; | |
225 | ||
226 | if (init) { | |
227 | ctx->enc = enc; | |
228 | if (con.iv) | |
229 | memcpy(ctx->iv, con.iv->iv, ivsize); | |
230 | ||
231 | ctx->aead_assoclen = con.aead_assoclen; | |
232 | } | |
233 | ||
234 | while (size) { | |
652d5b8a | 235 | size_t len = size; |
400c40cf SM |
236 | struct scatterlist *sg = NULL; |
237 | ||
238 | /* use the existing memory in an allocated page */ | |
239 | if (ctx->merge) { | |
240 | sg = sgl->sg + sgl->cur - 1; | |
241 | len = min_t(unsigned long, len, | |
242 | PAGE_SIZE - sg->offset - sg->length); | |
243 | err = memcpy_from_msg(page_address(sg_page(sg)) + | |
244 | sg->offset + sg->length, | |
245 | msg, len); | |
246 | if (err) | |
247 | goto unlock; | |
248 | ||
249 | sg->length += len; | |
250 | ctx->merge = (sg->offset + sg->length) & | |
251 | (PAGE_SIZE - 1); | |
252 | ||
253 | ctx->used += len; | |
254 | copied += len; | |
255 | size -= len; | |
256 | continue; | |
257 | } | |
258 | ||
259 | if (!aead_writable(sk)) { | |
260 | /* user space sent too much data */ | |
261 | aead_put_sgl(sk); | |
262 | err = -EMSGSIZE; | |
263 | goto unlock; | |
264 | } | |
265 | ||
266 | /* allocate a new page */ | |
267 | len = min_t(unsigned long, size, aead_sndbuf(sk)); | |
268 | while (len) { | |
652d5b8a | 269 | size_t plen = 0; |
400c40cf SM |
270 | |
271 | if (sgl->cur >= ALG_MAX_PAGES) { | |
272 | aead_put_sgl(sk); | |
273 | err = -E2BIG; | |
274 | goto unlock; | |
275 | } | |
276 | ||
277 | sg = sgl->sg + sgl->cur; | |
652d5b8a | 278 | plen = min_t(size_t, len, PAGE_SIZE); |
400c40cf SM |
279 | |
280 | sg_assign_page(sg, alloc_page(GFP_KERNEL)); | |
281 | err = -ENOMEM; | |
282 | if (!sg_page(sg)) | |
283 | goto unlock; | |
284 | ||
285 | err = memcpy_from_msg(page_address(sg_page(sg)), | |
286 | msg, plen); | |
287 | if (err) { | |
288 | __free_page(sg_page(sg)); | |
289 | sg_assign_page(sg, NULL); | |
290 | goto unlock; | |
291 | } | |
292 | ||
293 | sg->offset = 0; | |
294 | sg->length = plen; | |
295 | len -= plen; | |
296 | ctx->used += plen; | |
297 | copied += plen; | |
298 | sgl->cur++; | |
299 | size -= plen; | |
300 | ctx->merge = plen & (PAGE_SIZE - 1); | |
301 | } | |
302 | } | |
303 | ||
304 | err = 0; | |
305 | ||
306 | ctx->more = msg->msg_flags & MSG_MORE; | |
307 | if (!ctx->more && !aead_sufficient_data(ctx)) { | |
308 | aead_put_sgl(sk); | |
309 | err = -EMSGSIZE; | |
310 | } | |
311 | ||
312 | unlock: | |
313 | aead_data_wakeup(sk); | |
314 | release_sock(sk); | |
315 | ||
316 | return err ?: copied; | |
317 | } | |
318 | ||
319 | static ssize_t aead_sendpage(struct socket *sock, struct page *page, | |
320 | int offset, size_t size, int flags) | |
321 | { | |
322 | struct sock *sk = sock->sk; | |
323 | struct alg_sock *ask = alg_sk(sk); | |
324 | struct aead_ctx *ctx = ask->private; | |
325 | struct aead_sg_list *sgl = &ctx->tsgl; | |
326 | int err = -EINVAL; | |
327 | ||
328 | if (flags & MSG_SENDPAGE_NOTLAST) | |
329 | flags |= MSG_MORE; | |
330 | ||
331 | if (sgl->cur >= ALG_MAX_PAGES) | |
332 | return -E2BIG; | |
333 | ||
334 | lock_sock(sk); | |
335 | if (!ctx->more && ctx->used) | |
336 | goto unlock; | |
337 | ||
338 | if (!size) | |
339 | goto done; | |
340 | ||
341 | if (!aead_writable(sk)) { | |
342 | /* user space sent too much data */ | |
343 | aead_put_sgl(sk); | |
344 | err = -EMSGSIZE; | |
345 | goto unlock; | |
346 | } | |
347 | ||
348 | ctx->merge = 0; | |
349 | ||
350 | get_page(page); | |
351 | sg_set_page(sgl->sg + sgl->cur, page, size, offset); | |
352 | sgl->cur++; | |
353 | ctx->used += size; | |
354 | ||
355 | err = 0; | |
356 | ||
357 | done: | |
358 | ctx->more = flags & MSG_MORE; | |
359 | if (!ctx->more && !aead_sufficient_data(ctx)) { | |
360 | aead_put_sgl(sk); | |
361 | err = -EMSGSIZE; | |
362 | } | |
363 | ||
364 | unlock: | |
365 | aead_data_wakeup(sk); | |
366 | release_sock(sk); | |
367 | ||
368 | return err ?: size; | |
369 | } | |
370 | ||
83094e5e TS |
371 | #define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \ |
372 | ((char *)req + sizeof(struct aead_request) + \ | |
373 | crypto_aead_reqsize(tfm)) | |
374 | ||
375 | #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \ | |
376 | crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \ | |
377 | sizeof(struct aead_request) | |
378 | ||
379 | static void aead_async_cb(struct crypto_async_request *_req, int err) | |
380 | { | |
381 | struct sock *sk = _req->data; | |
382 | struct alg_sock *ask = alg_sk(sk); | |
383 | struct aead_ctx *ctx = ask->private; | |
384 | struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req); | |
385 | struct aead_request *req = aead_request_cast(_req); | |
386 | struct aead_async_req *areq = GET_ASYM_REQ(req, tfm); | |
387 | struct scatterlist *sg = areq->tsgl; | |
388 | struct aead_async_rsgl *rsgl; | |
389 | struct kiocb *iocb = areq->iocb; | |
390 | unsigned int i, reqlen = GET_REQ_SIZE(tfm); | |
391 | ||
392 | list_for_each_entry(rsgl, &areq->list, list) { | |
393 | af_alg_free_sg(&rsgl->sgl); | |
394 | if (rsgl != &areq->first_rsgl) | |
395 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); | |
396 | } | |
397 | ||
398 | for (i = 0; i < areq->tsgls; i++) | |
399 | put_page(sg_page(sg + i)); | |
400 | ||
401 | sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls); | |
402 | sock_kfree_s(sk, req, reqlen); | |
403 | __sock_put(sk); | |
404 | iocb->ki_complete(iocb, err, err); | |
405 | } | |
406 | ||
407 | static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg, | |
408 | int flags) | |
409 | { | |
410 | struct sock *sk = sock->sk; | |
411 | struct alg_sock *ask = alg_sk(sk); | |
412 | struct aead_ctx *ctx = ask->private; | |
413 | struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req); | |
414 | struct aead_async_req *areq; | |
415 | struct aead_request *req = NULL; | |
416 | struct aead_sg_list *sgl = &ctx->tsgl; | |
417 | struct aead_async_rsgl *last_rsgl = NULL, *rsgl; | |
418 | unsigned int as = crypto_aead_authsize(tfm); | |
419 | unsigned int i, reqlen = GET_REQ_SIZE(tfm); | |
420 | int err = -ENOMEM; | |
421 | unsigned long used; | |
678b5c6b | 422 | size_t outlen = 0; |
83094e5e TS |
423 | size_t usedpages = 0; |
424 | ||
425 | lock_sock(sk); | |
426 | if (ctx->more) { | |
427 | err = aead_wait_for_data(sk, flags); | |
428 | if (err) | |
429 | goto unlock; | |
430 | } | |
431 | ||
83094e5e TS |
432 | if (!aead_sufficient_data(ctx)) |
433 | goto unlock; | |
434 | ||
0c1e16cd SM |
435 | used = ctx->used; |
436 | if (ctx->enc) | |
437 | outlen = used + as; | |
438 | else | |
439 | outlen = used - as; | |
440 | ||
83094e5e TS |
441 | req = sock_kmalloc(sk, reqlen, GFP_KERNEL); |
442 | if (unlikely(!req)) | |
443 | goto unlock; | |
444 | ||
445 | areq = GET_ASYM_REQ(req, tfm); | |
446 | memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl)); | |
447 | INIT_LIST_HEAD(&areq->list); | |
448 | areq->iocb = msg->msg_iocb; | |
449 | memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm)); | |
450 | aead_request_set_tfm(req, tfm); | |
451 | aead_request_set_ad(req, ctx->aead_assoclen); | |
452 | aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
453 | aead_async_cb, sk); | |
0c1e16cd | 454 | used -= ctx->aead_assoclen; |
83094e5e TS |
455 | |
456 | /* take over all tx sgls from ctx */ | |
5937d81a SM |
457 | areq->tsgl = sock_kmalloc(sk, |
458 | sizeof(*areq->tsgl) * max_t(u32, sgl->cur, 1), | |
83094e5e TS |
459 | GFP_KERNEL); |
460 | if (unlikely(!areq->tsgl)) | |
461 | goto free; | |
462 | ||
5937d81a | 463 | sg_init_table(areq->tsgl, max_t(u32, sgl->cur, 1)); |
83094e5e TS |
464 | for (i = 0; i < sgl->cur; i++) |
465 | sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]), | |
466 | sgl->sg[i].length, sgl->sg[i].offset); | |
467 | ||
468 | areq->tsgls = sgl->cur; | |
469 | ||
470 | /* create rx sgls */ | |
0c1e16cd | 471 | while (outlen > usedpages && iov_iter_count(&msg->msg_iter)) { |
83094e5e TS |
472 | size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter), |
473 | (outlen - usedpages)); | |
474 | ||
475 | if (list_empty(&areq->list)) { | |
476 | rsgl = &areq->first_rsgl; | |
477 | ||
478 | } else { | |
479 | rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); | |
480 | if (unlikely(!rsgl)) { | |
481 | err = -ENOMEM; | |
482 | goto free; | |
483 | } | |
484 | } | |
485 | rsgl->sgl.npages = 0; | |
486 | list_add_tail(&rsgl->list, &areq->list); | |
487 | ||
488 | /* make one iovec available as scatterlist */ | |
489 | err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); | |
490 | if (err < 0) | |
491 | goto free; | |
492 | ||
493 | usedpages += err; | |
494 | ||
495 | /* chain the new scatterlist with previous one */ | |
496 | if (last_rsgl) | |
497 | af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl); | |
498 | ||
499 | last_rsgl = rsgl; | |
500 | ||
83094e5e TS |
501 | iov_iter_advance(&msg->msg_iter, err); |
502 | } | |
0c1e16cd | 503 | |
83094e5e | 504 | /* ensure output buffer is sufficiently large */ |
0c1e16cd SM |
505 | if (usedpages < outlen) { |
506 | err = -EINVAL; | |
507 | goto unlock; | |
508 | } | |
83094e5e TS |
509 | |
510 | aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used, | |
511 | areq->iv); | |
512 | err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); | |
513 | if (err) { | |
514 | if (err == -EINPROGRESS) { | |
515 | sock_hold(sk); | |
516 | err = -EIOCBQUEUED; | |
517 | aead_reset_ctx(ctx); | |
518 | goto unlock; | |
519 | } else if (err == -EBADMSG) { | |
520 | aead_put_sgl(sk); | |
521 | } | |
522 | goto free; | |
523 | } | |
524 | aead_put_sgl(sk); | |
525 | ||
526 | free: | |
527 | list_for_each_entry(rsgl, &areq->list, list) { | |
528 | af_alg_free_sg(&rsgl->sgl); | |
529 | if (rsgl != &areq->first_rsgl) | |
530 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); | |
531 | } | |
532 | if (areq->tsgl) | |
533 | sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls); | |
534 | if (req) | |
535 | sock_kfree_s(sk, req, reqlen); | |
536 | unlock: | |
537 | aead_wmem_wakeup(sk); | |
538 | release_sock(sk); | |
539 | return err ? err : outlen; | |
540 | } | |
541 | ||
542 | static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags) | |
400c40cf SM |
543 | { |
544 | struct sock *sk = sock->sk; | |
545 | struct alg_sock *ask = alg_sk(sk); | |
546 | struct aead_ctx *ctx = ask->private; | |
400c40cf SM |
547 | unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req)); |
548 | struct aead_sg_list *sgl = &ctx->tsgl; | |
83094e5e TS |
549 | struct aead_async_rsgl *last_rsgl = NULL; |
550 | struct aead_async_rsgl *rsgl, *tmp; | |
400c40cf SM |
551 | int err = -EINVAL; |
552 | unsigned long used = 0; | |
553 | size_t outlen = 0; | |
554 | size_t usedpages = 0; | |
400c40cf SM |
555 | |
556 | lock_sock(sk); | |
557 | ||
558 | /* | |
3f692d5f SM |
559 | * Please see documentation of aead_request_set_crypt for the |
560 | * description of the AEAD memory structure expected from the caller. | |
400c40cf SM |
561 | */ |
562 | ||
563 | if (ctx->more) { | |
564 | err = aead_wait_for_data(sk, flags); | |
565 | if (err) | |
566 | goto unlock; | |
567 | } | |
568 | ||
0c1e16cd | 569 | /* data length provided by caller via sendmsg/sendpage */ |
400c40cf SM |
570 | used = ctx->used; |
571 | ||
572 | /* | |
573 | * Make sure sufficient data is present -- note, the same check is | |
574 | * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg | |
575 | * shall provide an information to the data sender that something is | |
576 | * wrong, but they are irrelevant to maintain the kernel integrity. | |
577 | * We need this check here too in case user space decides to not honor | |
578 | * the error message in sendmsg/sendpage and still call recvmsg. This | |
579 | * check here protects the kernel integrity. | |
580 | */ | |
581 | if (!aead_sufficient_data(ctx)) | |
582 | goto unlock; | |
583 | ||
0c1e16cd SM |
584 | /* |
585 | * Calculate the minimum output buffer size holding the result of the | |
586 | * cipher operation. When encrypting data, the receiving buffer is | |
587 | * larger by the tag length compared to the input buffer as the | |
588 | * encryption operation generates the tag. For decryption, the input | |
589 | * buffer provides the tag which is consumed resulting in only the | |
590 | * plaintext without a buffer for the tag returned to the caller. | |
591 | */ | |
592 | if (ctx->enc) | |
593 | outlen = used + as; | |
594 | else | |
595 | outlen = used - as; | |
19fa7752 | 596 | |
400c40cf SM |
597 | /* |
598 | * The cipher operation input data is reduced by the associated data | |
599 | * length as this data is processed separately later on. | |
600 | */ | |
0c1e16cd | 601 | used -= ctx->aead_assoclen; |
400c40cf SM |
602 | |
603 | /* convert iovecs of output buffers into scatterlists */ | |
0c1e16cd | 604 | while (outlen > usedpages && iov_iter_count(&msg->msg_iter)) { |
400c40cf SM |
605 | size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter), |
606 | (outlen - usedpages)); | |
607 | ||
83094e5e TS |
608 | if (list_empty(&ctx->list)) { |
609 | rsgl = &ctx->first_rsgl; | |
610 | } else { | |
611 | rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); | |
612 | if (unlikely(!rsgl)) { | |
613 | err = -ENOMEM; | |
614 | goto unlock; | |
615 | } | |
616 | } | |
617 | rsgl->sgl.npages = 0; | |
618 | list_add_tail(&rsgl->list, &ctx->list); | |
619 | ||
400c40cf | 620 | /* make one iovec available as scatterlist */ |
83094e5e | 621 | err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); |
400c40cf SM |
622 | if (err < 0) |
623 | goto unlock; | |
624 | usedpages += err; | |
7b2a18e0 | 625 | /* chain the new scatterlist with previous one */ |
83094e5e TS |
626 | if (last_rsgl) |
627 | af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl); | |
628 | ||
629 | last_rsgl = rsgl; | |
7b2a18e0 | 630 | |
400c40cf | 631 | iov_iter_advance(&msg->msg_iter, err); |
400c40cf SM |
632 | } |
633 | ||
400c40cf | 634 | /* ensure output buffer is sufficiently large */ |
0c1e16cd SM |
635 | if (usedpages < outlen) { |
636 | err = -EINVAL; | |
400c40cf | 637 | goto unlock; |
0c1e16cd | 638 | } |
400c40cf | 639 | |
19fa7752 | 640 | sg_mark_end(sgl->sg + sgl->cur - 1); |
83094e5e | 641 | aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg, |
19fa7752 HX |
642 | used, ctx->iv); |
643 | aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen); | |
400c40cf SM |
644 | |
645 | err = af_alg_wait_for_completion(ctx->enc ? | |
646 | crypto_aead_encrypt(&ctx->aead_req) : | |
647 | crypto_aead_decrypt(&ctx->aead_req), | |
648 | &ctx->completion); | |
649 | ||
650 | if (err) { | |
651 | /* EBADMSG implies a valid cipher operation took place */ | |
652 | if (err == -EBADMSG) | |
653 | aead_put_sgl(sk); | |
83094e5e | 654 | |
400c40cf SM |
655 | goto unlock; |
656 | } | |
657 | ||
658 | aead_put_sgl(sk); | |
400c40cf SM |
659 | err = 0; |
660 | ||
661 | unlock: | |
83094e5e TS |
662 | list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) { |
663 | af_alg_free_sg(&rsgl->sgl); | |
0b529f14 | 664 | list_del(&rsgl->list); |
83094e5e TS |
665 | if (rsgl != &ctx->first_rsgl) |
666 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); | |
83094e5e TS |
667 | } |
668 | INIT_LIST_HEAD(&ctx->list); | |
400c40cf SM |
669 | aead_wmem_wakeup(sk); |
670 | release_sock(sk); | |
671 | ||
672 | return err ? err : outlen; | |
673 | } | |
674 | ||
83094e5e TS |
675 | static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, |
676 | int flags) | |
677 | { | |
678 | return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ? | |
679 | aead_recvmsg_async(sock, msg, flags) : | |
680 | aead_recvmsg_sync(sock, msg, flags); | |
681 | } | |
682 | ||
400c40cf SM |
683 | static unsigned int aead_poll(struct file *file, struct socket *sock, |
684 | poll_table *wait) | |
685 | { | |
686 | struct sock *sk = sock->sk; | |
687 | struct alg_sock *ask = alg_sk(sk); | |
688 | struct aead_ctx *ctx = ask->private; | |
689 | unsigned int mask; | |
690 | ||
691 | sock_poll_wait(file, sk_sleep(sk), wait); | |
692 | mask = 0; | |
693 | ||
694 | if (!ctx->more) | |
695 | mask |= POLLIN | POLLRDNORM; | |
696 | ||
697 | if (aead_writable(sk)) | |
698 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
699 | ||
700 | return mask; | |
701 | } | |
702 | ||
703 | static struct proto_ops algif_aead_ops = { | |
704 | .family = PF_ALG, | |
705 | ||
706 | .connect = sock_no_connect, | |
707 | .socketpair = sock_no_socketpair, | |
708 | .getname = sock_no_getname, | |
709 | .ioctl = sock_no_ioctl, | |
710 | .listen = sock_no_listen, | |
711 | .shutdown = sock_no_shutdown, | |
712 | .getsockopt = sock_no_getsockopt, | |
713 | .mmap = sock_no_mmap, | |
714 | .bind = sock_no_bind, | |
715 | .accept = sock_no_accept, | |
716 | .setsockopt = sock_no_setsockopt, | |
717 | ||
718 | .release = af_alg_release, | |
719 | .sendmsg = aead_sendmsg, | |
720 | .sendpage = aead_sendpage, | |
721 | .recvmsg = aead_recvmsg, | |
722 | .poll = aead_poll, | |
723 | }; | |
724 | ||
725 | static void *aead_bind(const char *name, u32 type, u32 mask) | |
726 | { | |
5e4b8c1f | 727 | return crypto_alloc_aead(name, type, mask); |
400c40cf SM |
728 | } |
729 | ||
730 | static void aead_release(void *private) | |
731 | { | |
732 | crypto_free_aead(private); | |
733 | } | |
734 | ||
735 | static int aead_setauthsize(void *private, unsigned int authsize) | |
736 | { | |
737 | return crypto_aead_setauthsize(private, authsize); | |
738 | } | |
739 | ||
740 | static int aead_setkey(void *private, const u8 *key, unsigned int keylen) | |
741 | { | |
742 | return crypto_aead_setkey(private, key, keylen); | |
743 | } | |
744 | ||
745 | static void aead_sock_destruct(struct sock *sk) | |
746 | { | |
747 | struct alg_sock *ask = alg_sk(sk); | |
748 | struct aead_ctx *ctx = ask->private; | |
749 | unsigned int ivlen = crypto_aead_ivsize( | |
750 | crypto_aead_reqtfm(&ctx->aead_req)); | |
751 | ||
83094e5e | 752 | WARN_ON(atomic_read(&sk->sk_refcnt) != 0); |
400c40cf SM |
753 | aead_put_sgl(sk); |
754 | sock_kzfree_s(sk, ctx->iv, ivlen); | |
755 | sock_kfree_s(sk, ctx, ctx->len); | |
756 | af_alg_release_parent(sk); | |
757 | } | |
758 | ||
759 | static int aead_accept_parent(void *private, struct sock *sk) | |
760 | { | |
761 | struct aead_ctx *ctx; | |
762 | struct alg_sock *ask = alg_sk(sk); | |
763 | unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(private); | |
764 | unsigned int ivlen = crypto_aead_ivsize(private); | |
765 | ||
766 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
767 | if (!ctx) | |
768 | return -ENOMEM; | |
769 | memset(ctx, 0, len); | |
770 | ||
771 | ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL); | |
772 | if (!ctx->iv) { | |
773 | sock_kfree_s(sk, ctx, len); | |
774 | return -ENOMEM; | |
775 | } | |
776 | memset(ctx->iv, 0, ivlen); | |
777 | ||
778 | ctx->len = len; | |
779 | ctx->used = 0; | |
780 | ctx->more = 0; | |
781 | ctx->merge = 0; | |
782 | ctx->enc = 0; | |
783 | ctx->tsgl.cur = 0; | |
784 | ctx->aead_assoclen = 0; | |
785 | af_alg_init_completion(&ctx->completion); | |
786 | sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES); | |
83094e5e | 787 | INIT_LIST_HEAD(&ctx->list); |
400c40cf SM |
788 | |
789 | ask->private = ctx; | |
790 | ||
791 | aead_request_set_tfm(&ctx->aead_req, private); | |
792 | aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
793 | af_alg_complete, &ctx->completion); | |
794 | ||
795 | sk->sk_destruct = aead_sock_destruct; | |
796 | ||
797 | return 0; | |
798 | } | |
799 | ||
800 | static const struct af_alg_type algif_type_aead = { | |
801 | .bind = aead_bind, | |
802 | .release = aead_release, | |
803 | .setkey = aead_setkey, | |
804 | .setauthsize = aead_setauthsize, | |
805 | .accept = aead_accept_parent, | |
806 | .ops = &algif_aead_ops, | |
807 | .name = "aead", | |
808 | .owner = THIS_MODULE | |
809 | }; | |
810 | ||
811 | static int __init algif_aead_init(void) | |
812 | { | |
813 | return af_alg_register_type(&algif_type_aead); | |
814 | } | |
815 | ||
816 | static void __exit algif_aead_exit(void) | |
817 | { | |
818 | int err = af_alg_unregister_type(&algif_type_aead); | |
819 | BUG_ON(err); | |
820 | } | |
821 | ||
822 | module_init(algif_aead_init); | |
823 | module_exit(algif_aead_exit); | |
824 | MODULE_LICENSE("GPL"); | |
825 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
826 | MODULE_DESCRIPTION("AEAD kernel crypto API user space interface"); |