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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
16 #include <crypto/internal/aead.h>
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/sched/signal.h>
23 #include <linux/mm.h>
24 #include <linux/module.h>
25 #include <linux/net.h>
26 #include <net/sock.h>
27
28 struct aead_sg_list {
29 unsigned int cur;
30 struct scatterlist sg[ALG_MAX_PAGES];
31 };
32
33 struct aead_async_rsgl {
34 struct af_alg_sgl sgl;
35 struct list_head list;
36 };
37
38 struct aead_async_req {
39 struct scatterlist *tsgl;
40 struct aead_async_rsgl first_rsgl;
41 struct list_head list;
42 struct kiocb *iocb;
43 struct sock *sk;
44 unsigned int tsgls;
45 char iv[];
46 };
47
48 struct aead_tfm {
49 struct crypto_aead *aead;
50 bool has_key;
51 };
52
53 struct aead_ctx {
54 struct aead_sg_list tsgl;
55 struct aead_async_rsgl first_rsgl;
56 struct list_head list;
57
58 void *iv;
59
60 struct af_alg_completion completion;
61
62 unsigned long used;
63
64 unsigned int len;
65 bool more;
66 bool merge;
67 bool enc;
68
69 size_t aead_assoclen;
70 struct aead_request aead_req;
71 };
72
73 static inline int aead_sndbuf(struct sock *sk)
74 {
75 struct alg_sock *ask = alg_sk(sk);
76 struct aead_ctx *ctx = ask->private;
77
78 return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
79 ctx->used, 0);
80 }
81
82 static inline bool aead_writable(struct sock *sk)
83 {
84 return PAGE_SIZE <= aead_sndbuf(sk);
85 }
86
87 static inline bool aead_sufficient_data(struct aead_ctx *ctx)
88 {
89 unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
90
91 /*
92 * The minimum amount of memory needed for an AEAD cipher is
93 * the AAD and in case of decryption the tag.
94 */
95 return ctx->used >= ctx->aead_assoclen + (ctx->enc ? 0 : as);
96 }
97
98 static void aead_reset_ctx(struct aead_ctx *ctx)
99 {
100 struct aead_sg_list *sgl = &ctx->tsgl;
101
102 sg_init_table(sgl->sg, ALG_MAX_PAGES);
103 sgl->cur = 0;
104 ctx->used = 0;
105 ctx->more = 0;
106 ctx->merge = 0;
107 }
108
109 static void aead_put_sgl(struct sock *sk)
110 {
111 struct alg_sock *ask = alg_sk(sk);
112 struct aead_ctx *ctx = ask->private;
113 struct aead_sg_list *sgl = &ctx->tsgl;
114 struct scatterlist *sg = sgl->sg;
115 unsigned int i;
116
117 for (i = 0; i < sgl->cur; i++) {
118 if (!sg_page(sg + i))
119 continue;
120
121 put_page(sg_page(sg + i));
122 sg_assign_page(sg + i, NULL);
123 }
124 aead_reset_ctx(ctx);
125 }
126
127 static void aead_wmem_wakeup(struct sock *sk)
128 {
129 struct socket_wq *wq;
130
131 if (!aead_writable(sk))
132 return;
133
134 rcu_read_lock();
135 wq = rcu_dereference(sk->sk_wq);
136 if (skwq_has_sleeper(wq))
137 wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
138 POLLRDNORM |
139 POLLRDBAND);
140 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
141 rcu_read_unlock();
142 }
143
144 static int aead_wait_for_data(struct sock *sk, unsigned flags)
145 {
146 DEFINE_WAIT_FUNC(wait, woken_wake_function);
147 struct alg_sock *ask = alg_sk(sk);
148 struct aead_ctx *ctx = ask->private;
149 long timeout;
150 int err = -ERESTARTSYS;
151
152 if (flags & MSG_DONTWAIT)
153 return -EAGAIN;
154
155 sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
156 add_wait_queue(sk_sleep(sk), &wait);
157 for (;;) {
158 if (signal_pending(current))
159 break;
160 timeout = MAX_SCHEDULE_TIMEOUT;
161 if (sk_wait_event(sk, &timeout, !ctx->more, &wait)) {
162 err = 0;
163 break;
164 }
165 }
166 remove_wait_queue(sk_sleep(sk), &wait);
167
168 sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
169
170 return err;
171 }
172
173 static void aead_data_wakeup(struct sock *sk)
174 {
175 struct alg_sock *ask = alg_sk(sk);
176 struct aead_ctx *ctx = ask->private;
177 struct socket_wq *wq;
178
179 if (ctx->more)
180 return;
181 if (!ctx->used)
182 return;
183
184 rcu_read_lock();
185 wq = rcu_dereference(sk->sk_wq);
186 if (skwq_has_sleeper(wq))
187 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
188 POLLRDNORM |
189 POLLRDBAND);
190 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
191 rcu_read_unlock();
192 }
193
194 static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
195 {
196 struct sock *sk = sock->sk;
197 struct alg_sock *ask = alg_sk(sk);
198 struct aead_ctx *ctx = ask->private;
199 unsigned ivsize =
200 crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req));
201 struct aead_sg_list *sgl = &ctx->tsgl;
202 struct af_alg_control con = {};
203 long copied = 0;
204 bool enc = 0;
205 bool init = 0;
206 int err = -EINVAL;
207
208 if (msg->msg_controllen) {
209 err = af_alg_cmsg_send(msg, &con);
210 if (err)
211 return err;
212
213 init = 1;
214 switch (con.op) {
215 case ALG_OP_ENCRYPT:
216 enc = 1;
217 break;
218 case ALG_OP_DECRYPT:
219 enc = 0;
220 break;
221 default:
222 return -EINVAL;
223 }
224
225 if (con.iv && con.iv->ivlen != ivsize)
226 return -EINVAL;
227 }
228
229 lock_sock(sk);
230 if (!ctx->more && ctx->used)
231 goto unlock;
232
233 if (init) {
234 ctx->enc = enc;
235 if (con.iv)
236 memcpy(ctx->iv, con.iv->iv, ivsize);
237
238 ctx->aead_assoclen = con.aead_assoclen;
239 }
240
241 while (size) {
242 size_t len = size;
243 struct scatterlist *sg = NULL;
244
245 /* use the existing memory in an allocated page */
246 if (ctx->merge) {
247 sg = sgl->sg + sgl->cur - 1;
248 len = min_t(unsigned long, len,
249 PAGE_SIZE - sg->offset - sg->length);
250 err = memcpy_from_msg(page_address(sg_page(sg)) +
251 sg->offset + sg->length,
252 msg, len);
253 if (err)
254 goto unlock;
255
256 sg->length += len;
257 ctx->merge = (sg->offset + sg->length) &
258 (PAGE_SIZE - 1);
259
260 ctx->used += len;
261 copied += len;
262 size -= len;
263 continue;
264 }
265
266 if (!aead_writable(sk)) {
267 /* user space sent too much data */
268 aead_put_sgl(sk);
269 err = -EMSGSIZE;
270 goto unlock;
271 }
272
273 /* allocate a new page */
274 len = min_t(unsigned long, size, aead_sndbuf(sk));
275 while (len) {
276 size_t plen = 0;
277
278 if (sgl->cur >= ALG_MAX_PAGES) {
279 aead_put_sgl(sk);
280 err = -E2BIG;
281 goto unlock;
282 }
283
284 sg = sgl->sg + sgl->cur;
285 plen = min_t(size_t, len, PAGE_SIZE);
286
287 sg_assign_page(sg, alloc_page(GFP_KERNEL));
288 err = -ENOMEM;
289 if (!sg_page(sg))
290 goto unlock;
291
292 err = memcpy_from_msg(page_address(sg_page(sg)),
293 msg, plen);
294 if (err) {
295 __free_page(sg_page(sg));
296 sg_assign_page(sg, NULL);
297 goto unlock;
298 }
299
300 sg->offset = 0;
301 sg->length = plen;
302 len -= plen;
303 ctx->used += plen;
304 copied += plen;
305 sgl->cur++;
306 size -= plen;
307 ctx->merge = plen & (PAGE_SIZE - 1);
308 }
309 }
310
311 err = 0;
312
313 ctx->more = msg->msg_flags & MSG_MORE;
314 if (!ctx->more && !aead_sufficient_data(ctx)) {
315 aead_put_sgl(sk);
316 err = -EMSGSIZE;
317 }
318
319 unlock:
320 aead_data_wakeup(sk);
321 release_sock(sk);
322
323 return err ?: copied;
324 }
325
326 static ssize_t aead_sendpage(struct socket *sock, struct page *page,
327 int offset, size_t size, int flags)
328 {
329 struct sock *sk = sock->sk;
330 struct alg_sock *ask = alg_sk(sk);
331 struct aead_ctx *ctx = ask->private;
332 struct aead_sg_list *sgl = &ctx->tsgl;
333 int err = -EINVAL;
334
335 if (flags & MSG_SENDPAGE_NOTLAST)
336 flags |= MSG_MORE;
337
338 if (sgl->cur >= ALG_MAX_PAGES)
339 return -E2BIG;
340
341 lock_sock(sk);
342 if (!ctx->more && ctx->used)
343 goto unlock;
344
345 if (!size)
346 goto done;
347
348 if (!aead_writable(sk)) {
349 /* user space sent too much data */
350 aead_put_sgl(sk);
351 err = -EMSGSIZE;
352 goto unlock;
353 }
354
355 ctx->merge = 0;
356
357 get_page(page);
358 sg_set_page(sgl->sg + sgl->cur, page, size, offset);
359 sgl->cur++;
360 ctx->used += size;
361
362 err = 0;
363
364 done:
365 ctx->more = flags & MSG_MORE;
366 if (!ctx->more && !aead_sufficient_data(ctx)) {
367 aead_put_sgl(sk);
368 err = -EMSGSIZE;
369 }
370
371 unlock:
372 aead_data_wakeup(sk);
373 release_sock(sk);
374
375 return err ?: size;
376 }
377
378 #define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \
379 ((char *)req + sizeof(struct aead_request) + \
380 crypto_aead_reqsize(tfm))
381
382 #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \
383 crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \
384 sizeof(struct aead_request)
385
386 static void aead_async_cb(struct crypto_async_request *_req, int err)
387 {
388 struct aead_request *req = _req->data;
389 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
390 struct aead_async_req *areq = GET_ASYM_REQ(req, tfm);
391 struct sock *sk = areq->sk;
392 struct scatterlist *sg = areq->tsgl;
393 struct aead_async_rsgl *rsgl;
394 struct kiocb *iocb = areq->iocb;
395 unsigned int i, reqlen = GET_REQ_SIZE(tfm);
396
397 list_for_each_entry(rsgl, &areq->list, list) {
398 af_alg_free_sg(&rsgl->sgl);
399 if (rsgl != &areq->first_rsgl)
400 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
401 }
402
403 for (i = 0; i < areq->tsgls; i++)
404 put_page(sg_page(sg + i));
405
406 sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);
407 sock_kfree_s(sk, req, reqlen);
408 __sock_put(sk);
409 iocb->ki_complete(iocb, err, err);
410 }
411
412 static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg,
413 int flags)
414 {
415 struct sock *sk = sock->sk;
416 struct alg_sock *ask = alg_sk(sk);
417 struct aead_ctx *ctx = ask->private;
418 struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req);
419 struct aead_async_req *areq;
420 struct aead_request *req = NULL;
421 struct aead_sg_list *sgl = &ctx->tsgl;
422 struct aead_async_rsgl *last_rsgl = NULL, *rsgl;
423 unsigned int as = crypto_aead_authsize(tfm);
424 unsigned int i, reqlen = GET_REQ_SIZE(tfm);
425 int err = -ENOMEM;
426 unsigned long used;
427 size_t outlen = 0;
428 size_t usedpages = 0;
429
430 lock_sock(sk);
431 if (ctx->more) {
432 err = aead_wait_for_data(sk, flags);
433 if (err)
434 goto unlock;
435 }
436
437 if (!aead_sufficient_data(ctx))
438 goto unlock;
439
440 used = ctx->used;
441 if (ctx->enc)
442 outlen = used + as;
443 else
444 outlen = used - as;
445
446 req = sock_kmalloc(sk, reqlen, GFP_KERNEL);
447 if (unlikely(!req))
448 goto unlock;
449
450 areq = GET_ASYM_REQ(req, tfm);
451 memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl));
452 INIT_LIST_HEAD(&areq->list);
453 areq->iocb = msg->msg_iocb;
454 areq->sk = sk;
455 memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm));
456 aead_request_set_tfm(req, tfm);
457 aead_request_set_ad(req, ctx->aead_assoclen);
458 aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
459 aead_async_cb, req);
460 used -= ctx->aead_assoclen;
461
462 /* take over all tx sgls from ctx */
463 areq->tsgl = sock_kmalloc(sk,
464 sizeof(*areq->tsgl) * max_t(u32, sgl->cur, 1),
465 GFP_KERNEL);
466 if (unlikely(!areq->tsgl))
467 goto free;
468
469 sg_init_table(areq->tsgl, max_t(u32, sgl->cur, 1));
470 for (i = 0; i < sgl->cur; i++)
471 sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]),
472 sgl->sg[i].length, sgl->sg[i].offset);
473
474 areq->tsgls = sgl->cur;
475
476 /* create rx sgls */
477 while (outlen > usedpages && iov_iter_count(&msg->msg_iter)) {
478 size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
479 (outlen - usedpages));
480
481 if (list_empty(&areq->list)) {
482 rsgl = &areq->first_rsgl;
483
484 } else {
485 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
486 if (unlikely(!rsgl)) {
487 err = -ENOMEM;
488 goto free;
489 }
490 }
491 rsgl->sgl.npages = 0;
492 list_add_tail(&rsgl->list, &areq->list);
493
494 /* make one iovec available as scatterlist */
495 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
496 if (err < 0)
497 goto free;
498
499 usedpages += err;
500
501 /* chain the new scatterlist with previous one */
502 if (last_rsgl)
503 af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
504
505 last_rsgl = rsgl;
506
507 iov_iter_advance(&msg->msg_iter, err);
508 }
509
510 /* ensure output buffer is sufficiently large */
511 if (usedpages < outlen) {
512 err = -EINVAL;
513 goto unlock;
514 }
515
516 aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used,
517 areq->iv);
518 err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);
519 if (err) {
520 if (err == -EINPROGRESS) {
521 sock_hold(sk);
522 err = -EIOCBQUEUED;
523 aead_reset_ctx(ctx);
524 goto unlock;
525 } else if (err == -EBADMSG) {
526 aead_put_sgl(sk);
527 }
528 goto free;
529 }
530 aead_put_sgl(sk);
531
532 free:
533 list_for_each_entry(rsgl, &areq->list, list) {
534 af_alg_free_sg(&rsgl->sgl);
535 if (rsgl != &areq->first_rsgl)
536 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
537 }
538 if (areq->tsgl)
539 sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls);
540 if (req)
541 sock_kfree_s(sk, req, reqlen);
542 unlock:
543 aead_wmem_wakeup(sk);
544 release_sock(sk);
545 return err ? err : outlen;
546 }
547
548 static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags)
549 {
550 struct sock *sk = sock->sk;
551 struct alg_sock *ask = alg_sk(sk);
552 struct aead_ctx *ctx = ask->private;
553 unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
554 struct aead_sg_list *sgl = &ctx->tsgl;
555 struct aead_async_rsgl *last_rsgl = NULL;
556 struct aead_async_rsgl *rsgl, *tmp;
557 int err = -EINVAL;
558 unsigned long used = 0;
559 size_t outlen = 0;
560 size_t usedpages = 0;
561
562 lock_sock(sk);
563
564 /*
565 * Please see documentation of aead_request_set_crypt for the
566 * description of the AEAD memory structure expected from the caller.
567 */
568
569 if (ctx->more) {
570 err = aead_wait_for_data(sk, flags);
571 if (err)
572 goto unlock;
573 }
574
575 /* data length provided by caller via sendmsg/sendpage */
576 used = ctx->used;
577
578 /*
579 * Make sure sufficient data is present -- note, the same check is
580 * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
581 * shall provide an information to the data sender that something is
582 * wrong, but they are irrelevant to maintain the kernel integrity.
583 * We need this check here too in case user space decides to not honor
584 * the error message in sendmsg/sendpage and still call recvmsg. This
585 * check here protects the kernel integrity.
586 */
587 if (!aead_sufficient_data(ctx))
588 goto unlock;
589
590 /*
591 * Calculate the minimum output buffer size holding the result of the
592 * cipher operation. When encrypting data, the receiving buffer is
593 * larger by the tag length compared to the input buffer as the
594 * encryption operation generates the tag. For decryption, the input
595 * buffer provides the tag which is consumed resulting in only the
596 * plaintext without a buffer for the tag returned to the caller.
597 */
598 if (ctx->enc)
599 outlen = used + as;
600 else
601 outlen = used - as;
602
603 /*
604 * The cipher operation input data is reduced by the associated data
605 * length as this data is processed separately later on.
606 */
607 used -= ctx->aead_assoclen;
608
609 /* convert iovecs of output buffers into scatterlists */
610 while (outlen > usedpages && iov_iter_count(&msg->msg_iter)) {
611 size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
612 (outlen - usedpages));
613
614 if (list_empty(&ctx->list)) {
615 rsgl = &ctx->first_rsgl;
616 } else {
617 rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL);
618 if (unlikely(!rsgl)) {
619 err = -ENOMEM;
620 goto unlock;
621 }
622 }
623 rsgl->sgl.npages = 0;
624 list_add_tail(&rsgl->list, &ctx->list);
625
626 /* make one iovec available as scatterlist */
627 err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen);
628 if (err < 0)
629 goto unlock;
630 usedpages += err;
631 /* chain the new scatterlist with previous one */
632 if (last_rsgl)
633 af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl);
634
635 last_rsgl = rsgl;
636
637 iov_iter_advance(&msg->msg_iter, err);
638 }
639
640 /* ensure output buffer is sufficiently large */
641 if (usedpages < outlen) {
642 err = -EINVAL;
643 goto unlock;
644 }
645
646 sg_mark_end(sgl->sg + sgl->cur - 1);
647 aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg,
648 used, ctx->iv);
649 aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);
650
651 err = af_alg_wait_for_completion(ctx->enc ?
652 crypto_aead_encrypt(&ctx->aead_req) :
653 crypto_aead_decrypt(&ctx->aead_req),
654 &ctx->completion);
655
656 if (err) {
657 /* EBADMSG implies a valid cipher operation took place */
658 if (err == -EBADMSG)
659 aead_put_sgl(sk);
660
661 goto unlock;
662 }
663
664 aead_put_sgl(sk);
665 err = 0;
666
667 unlock:
668 list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) {
669 af_alg_free_sg(&rsgl->sgl);
670 list_del(&rsgl->list);
671 if (rsgl != &ctx->first_rsgl)
672 sock_kfree_s(sk, rsgl, sizeof(*rsgl));
673 }
674 INIT_LIST_HEAD(&ctx->list);
675 aead_wmem_wakeup(sk);
676 release_sock(sk);
677
678 return err ? err : outlen;
679 }
680
681 static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored,
682 int flags)
683 {
684 return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ?
685 aead_recvmsg_async(sock, msg, flags) :
686 aead_recvmsg_sync(sock, msg, flags);
687 }
688
689 static unsigned int aead_poll(struct file *file, struct socket *sock,
690 poll_table *wait)
691 {
692 struct sock *sk = sock->sk;
693 struct alg_sock *ask = alg_sk(sk);
694 struct aead_ctx *ctx = ask->private;
695 unsigned int mask;
696
697 sock_poll_wait(file, sk_sleep(sk), wait);
698 mask = 0;
699
700 if (!ctx->more)
701 mask |= POLLIN | POLLRDNORM;
702
703 if (aead_writable(sk))
704 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
705
706 return mask;
707 }
708
709 static struct proto_ops algif_aead_ops = {
710 .family = PF_ALG,
711
712 .connect = sock_no_connect,
713 .socketpair = sock_no_socketpair,
714 .getname = sock_no_getname,
715 .ioctl = sock_no_ioctl,
716 .listen = sock_no_listen,
717 .shutdown = sock_no_shutdown,
718 .getsockopt = sock_no_getsockopt,
719 .mmap = sock_no_mmap,
720 .bind = sock_no_bind,
721 .accept = sock_no_accept,
722 .setsockopt = sock_no_setsockopt,
723
724 .release = af_alg_release,
725 .sendmsg = aead_sendmsg,
726 .sendpage = aead_sendpage,
727 .recvmsg = aead_recvmsg,
728 .poll = aead_poll,
729 };
730
731 static int aead_check_key(struct socket *sock)
732 {
733 int err = 0;
734 struct sock *psk;
735 struct alg_sock *pask;
736 struct aead_tfm *tfm;
737 struct sock *sk = sock->sk;
738 struct alg_sock *ask = alg_sk(sk);
739
740 lock_sock(sk);
741 if (ask->refcnt)
742 goto unlock_child;
743
744 psk = ask->parent;
745 pask = alg_sk(ask->parent);
746 tfm = pask->private;
747
748 err = -ENOKEY;
749 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
750 if (!tfm->has_key)
751 goto unlock;
752
753 if (!pask->refcnt++)
754 sock_hold(psk);
755
756 ask->refcnt = 1;
757 sock_put(psk);
758
759 err = 0;
760
761 unlock:
762 release_sock(psk);
763 unlock_child:
764 release_sock(sk);
765
766 return err;
767 }
768
769 static int aead_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
770 size_t size)
771 {
772 int err;
773
774 err = aead_check_key(sock);
775 if (err)
776 return err;
777
778 return aead_sendmsg(sock, msg, size);
779 }
780
781 static ssize_t aead_sendpage_nokey(struct socket *sock, struct page *page,
782 int offset, size_t size, int flags)
783 {
784 int err;
785
786 err = aead_check_key(sock);
787 if (err)
788 return err;
789
790 return aead_sendpage(sock, page, offset, size, flags);
791 }
792
793 static int aead_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
794 size_t ignored, int flags)
795 {
796 int err;
797
798 err = aead_check_key(sock);
799 if (err)
800 return err;
801
802 return aead_recvmsg(sock, msg, ignored, flags);
803 }
804
805 static struct proto_ops algif_aead_ops_nokey = {
806 .family = PF_ALG,
807
808 .connect = sock_no_connect,
809 .socketpair = sock_no_socketpair,
810 .getname = sock_no_getname,
811 .ioctl = sock_no_ioctl,
812 .listen = sock_no_listen,
813 .shutdown = sock_no_shutdown,
814 .getsockopt = sock_no_getsockopt,
815 .mmap = sock_no_mmap,
816 .bind = sock_no_bind,
817 .accept = sock_no_accept,
818 .setsockopt = sock_no_setsockopt,
819
820 .release = af_alg_release,
821 .sendmsg = aead_sendmsg_nokey,
822 .sendpage = aead_sendpage_nokey,
823 .recvmsg = aead_recvmsg_nokey,
824 .poll = aead_poll,
825 };
826
827 static void *aead_bind(const char *name, u32 type, u32 mask)
828 {
829 struct aead_tfm *tfm;
830 struct crypto_aead *aead;
831
832 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
833 if (!tfm)
834 return ERR_PTR(-ENOMEM);
835
836 aead = crypto_alloc_aead(name, type, mask);
837 if (IS_ERR(aead)) {
838 kfree(tfm);
839 return ERR_CAST(aead);
840 }
841
842 tfm->aead = aead;
843
844 return tfm;
845 }
846
847 static void aead_release(void *private)
848 {
849 struct aead_tfm *tfm = private;
850
851 crypto_free_aead(tfm->aead);
852 kfree(tfm);
853 }
854
855 static int aead_setauthsize(void *private, unsigned int authsize)
856 {
857 struct aead_tfm *tfm = private;
858
859 return crypto_aead_setauthsize(tfm->aead, authsize);
860 }
861
862 static int aead_setkey(void *private, const u8 *key, unsigned int keylen)
863 {
864 struct aead_tfm *tfm = private;
865 int err;
866
867 err = crypto_aead_setkey(tfm->aead, key, keylen);
868 tfm->has_key = !err;
869
870 return err;
871 }
872
873 static void aead_sock_destruct(struct sock *sk)
874 {
875 struct alg_sock *ask = alg_sk(sk);
876 struct aead_ctx *ctx = ask->private;
877 unsigned int ivlen = crypto_aead_ivsize(
878 crypto_aead_reqtfm(&ctx->aead_req));
879
880 WARN_ON(refcount_read(&sk->sk_refcnt) != 0);
881 aead_put_sgl(sk);
882 sock_kzfree_s(sk, ctx->iv, ivlen);
883 sock_kfree_s(sk, ctx, ctx->len);
884 af_alg_release_parent(sk);
885 }
886
887 static int aead_accept_parent_nokey(void *private, struct sock *sk)
888 {
889 struct aead_ctx *ctx;
890 struct alg_sock *ask = alg_sk(sk);
891 struct aead_tfm *tfm = private;
892 struct crypto_aead *aead = tfm->aead;
893 unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(aead);
894 unsigned int ivlen = crypto_aead_ivsize(aead);
895
896 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
897 if (!ctx)
898 return -ENOMEM;
899 memset(ctx, 0, len);
900
901 ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL);
902 if (!ctx->iv) {
903 sock_kfree_s(sk, ctx, len);
904 return -ENOMEM;
905 }
906 memset(ctx->iv, 0, ivlen);
907
908 ctx->len = len;
909 ctx->used = 0;
910 ctx->more = 0;
911 ctx->merge = 0;
912 ctx->enc = 0;
913 ctx->tsgl.cur = 0;
914 ctx->aead_assoclen = 0;
915 af_alg_init_completion(&ctx->completion);
916 sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
917 INIT_LIST_HEAD(&ctx->list);
918
919 ask->private = ctx;
920
921 aead_request_set_tfm(&ctx->aead_req, aead);
922 aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
923 af_alg_complete, &ctx->completion);
924
925 sk->sk_destruct = aead_sock_destruct;
926
927 return 0;
928 }
929
930 static int aead_accept_parent(void *private, struct sock *sk)
931 {
932 struct aead_tfm *tfm = private;
933
934 if (!tfm->has_key)
935 return -ENOKEY;
936
937 return aead_accept_parent_nokey(private, sk);
938 }
939
940 static const struct af_alg_type algif_type_aead = {
941 .bind = aead_bind,
942 .release = aead_release,
943 .setkey = aead_setkey,
944 .setauthsize = aead_setauthsize,
945 .accept = aead_accept_parent,
946 .accept_nokey = aead_accept_parent_nokey,
947 .ops = &algif_aead_ops,
948 .ops_nokey = &algif_aead_ops_nokey,
949 .name = "aead",
950 .owner = THIS_MODULE
951 };
952
953 static int __init algif_aead_init(void)
954 {
955 return af_alg_register_type(&algif_type_aead);
956 }
957
958 static void __exit algif_aead_exit(void)
959 {
960 int err = af_alg_unregister_type(&algif_type_aead);
961 BUG_ON(err);
962 }
963
964 module_init(algif_aead_init);
965 module_exit(algif_aead_exit);
966 MODULE_LICENSE("GPL");
967 MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
968 MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");