• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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/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/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 
32 struct aead_tfm {
33 	struct crypto_aead *aead;
34 	bool has_key;
35 };
36 
37 struct aead_ctx {
38 	struct aead_sg_list tsgl;
39 	/*
40 	 * RSGL_MAX_ENTRIES is an artificial limit where user space at maximum
41 	 * can cause the kernel to allocate RSGL_MAX_ENTRIES * ALG_MAX_PAGES
42 	 * pages
43 	 */
44 #define RSGL_MAX_ENTRIES ALG_MAX_PAGES
45 	struct af_alg_sgl rsgl[RSGL_MAX_ENTRIES];
46 
47 	void *iv;
48 
49 	struct af_alg_completion completion;
50 
51 	unsigned long used;
52 
53 	unsigned int len;
54 	bool more;
55 	bool merge;
56 	bool enc;
57 
58 	size_t aead_assoclen;
59 	struct aead_request aead_req;
60 };
61 
aead_sndbuf(struct sock * sk)62 static inline int aead_sndbuf(struct sock *sk)
63 {
64 	struct alg_sock *ask = alg_sk(sk);
65 	struct aead_ctx *ctx = ask->private;
66 
67 	return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
68 			  ctx->used, 0);
69 }
70 
aead_writable(struct sock * sk)71 static inline bool aead_writable(struct sock *sk)
72 {
73 	return PAGE_SIZE <= aead_sndbuf(sk);
74 }
75 
aead_sufficient_data(struct aead_ctx * ctx)76 static inline bool aead_sufficient_data(struct aead_ctx *ctx)
77 {
78 	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
79 
80 	return ctx->used >= ctx->aead_assoclen + as;
81 }
82 
aead_put_sgl(struct sock * sk)83 static void aead_put_sgl(struct sock *sk)
84 {
85 	struct alg_sock *ask = alg_sk(sk);
86 	struct aead_ctx *ctx = ask->private;
87 	struct aead_sg_list *sgl = &ctx->tsgl;
88 	struct scatterlist *sg = sgl->sg;
89 	unsigned int i;
90 
91 	for (i = 0; i < sgl->cur; i++) {
92 		if (!sg_page(sg + i))
93 			continue;
94 
95 		put_page(sg_page(sg + i));
96 		sg_assign_page(sg + i, NULL);
97 	}
98 	sg_init_table(sg, ALG_MAX_PAGES);
99 	sgl->cur = 0;
100 	ctx->used = 0;
101 	ctx->more = 0;
102 	ctx->merge = 0;
103 }
104 
aead_wmem_wakeup(struct sock * sk)105 static void aead_wmem_wakeup(struct sock *sk)
106 {
107 	struct socket_wq *wq;
108 
109 	if (!aead_writable(sk))
110 		return;
111 
112 	rcu_read_lock();
113 	wq = rcu_dereference(sk->sk_wq);
114 	if (wq_has_sleeper(wq))
115 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
116 							   POLLRDNORM |
117 							   POLLRDBAND);
118 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
119 	rcu_read_unlock();
120 }
121 
aead_wait_for_data(struct sock * sk,unsigned flags)122 static int aead_wait_for_data(struct sock *sk, unsigned flags)
123 {
124 	struct alg_sock *ask = alg_sk(sk);
125 	struct aead_ctx *ctx = ask->private;
126 	long timeout;
127 	DEFINE_WAIT(wait);
128 	int err = -ERESTARTSYS;
129 
130 	if (flags & MSG_DONTWAIT)
131 		return -EAGAIN;
132 
133 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
134 
135 	for (;;) {
136 		if (signal_pending(current))
137 			break;
138 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
139 		timeout = MAX_SCHEDULE_TIMEOUT;
140 		if (sk_wait_event(sk, &timeout, !ctx->more)) {
141 			err = 0;
142 			break;
143 		}
144 	}
145 	finish_wait(sk_sleep(sk), &wait);
146 
147 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
148 
149 	return err;
150 }
151 
aead_data_wakeup(struct sock * sk)152 static void aead_data_wakeup(struct sock *sk)
153 {
154 	struct alg_sock *ask = alg_sk(sk);
155 	struct aead_ctx *ctx = ask->private;
156 	struct socket_wq *wq;
157 
158 	if (ctx->more)
159 		return;
160 	if (!ctx->used)
161 		return;
162 
163 	rcu_read_lock();
164 	wq = rcu_dereference(sk->sk_wq);
165 	if (wq_has_sleeper(wq))
166 		wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
167 							   POLLRDNORM |
168 							   POLLRDBAND);
169 	sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
170 	rcu_read_unlock();
171 }
172 
aead_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)173 static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
174 {
175 	struct sock *sk = sock->sk;
176 	struct alg_sock *ask = alg_sk(sk);
177 	struct aead_ctx *ctx = ask->private;
178 	unsigned ivsize =
179 		crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req));
180 	struct aead_sg_list *sgl = &ctx->tsgl;
181 	struct af_alg_control con = {};
182 	long copied = 0;
183 	bool enc = 0;
184 	bool init = 0;
185 	int err = -EINVAL;
186 
187 	if (msg->msg_controllen) {
188 		err = af_alg_cmsg_send(msg, &con);
189 		if (err)
190 			return err;
191 
192 		init = 1;
193 		switch (con.op) {
194 		case ALG_OP_ENCRYPT:
195 			enc = 1;
196 			break;
197 		case ALG_OP_DECRYPT:
198 			enc = 0;
199 			break;
200 		default:
201 			return -EINVAL;
202 		}
203 
204 		if (con.iv && con.iv->ivlen != ivsize)
205 			return -EINVAL;
206 	}
207 
208 	lock_sock(sk);
209 	if (!ctx->more && ctx->used)
210 		goto unlock;
211 
212 	if (init) {
213 		ctx->enc = enc;
214 		if (con.iv)
215 			memcpy(ctx->iv, con.iv->iv, ivsize);
216 
217 		ctx->aead_assoclen = con.aead_assoclen;
218 	}
219 
220 	while (size) {
221 		unsigned long len = size;
222 		struct scatterlist *sg = NULL;
223 
224 		/* use the existing memory in an allocated page */
225 		if (ctx->merge) {
226 			sg = sgl->sg + sgl->cur - 1;
227 			len = min_t(unsigned long, len,
228 				    PAGE_SIZE - sg->offset - sg->length);
229 			err = memcpy_from_msg(page_address(sg_page(sg)) +
230 					      sg->offset + sg->length,
231 					      msg, len);
232 			if (err)
233 				goto unlock;
234 
235 			sg->length += len;
236 			ctx->merge = (sg->offset + sg->length) &
237 				     (PAGE_SIZE - 1);
238 
239 			ctx->used += len;
240 			copied += len;
241 			size -= len;
242 			continue;
243 		}
244 
245 		if (!aead_writable(sk)) {
246 			/* user space sent too much data */
247 			aead_put_sgl(sk);
248 			err = -EMSGSIZE;
249 			goto unlock;
250 		}
251 
252 		/* allocate a new page */
253 		len = min_t(unsigned long, size, aead_sndbuf(sk));
254 		while (len) {
255 			int plen = 0;
256 
257 			if (sgl->cur >= ALG_MAX_PAGES) {
258 				aead_put_sgl(sk);
259 				err = -E2BIG;
260 				goto unlock;
261 			}
262 
263 			sg = sgl->sg + sgl->cur;
264 			plen = min_t(int, len, PAGE_SIZE);
265 
266 			sg_assign_page(sg, alloc_page(GFP_KERNEL));
267 			err = -ENOMEM;
268 			if (!sg_page(sg))
269 				goto unlock;
270 
271 			err = memcpy_from_msg(page_address(sg_page(sg)),
272 					      msg, plen);
273 			if (err) {
274 				__free_page(sg_page(sg));
275 				sg_assign_page(sg, NULL);
276 				goto unlock;
277 			}
278 
279 			sg->offset = 0;
280 			sg->length = plen;
281 			len -= plen;
282 			ctx->used += plen;
283 			copied += plen;
284 			sgl->cur++;
285 			size -= plen;
286 			ctx->merge = plen & (PAGE_SIZE - 1);
287 		}
288 	}
289 
290 	err = 0;
291 
292 	ctx->more = msg->msg_flags & MSG_MORE;
293 	if (!ctx->more && !aead_sufficient_data(ctx)) {
294 		aead_put_sgl(sk);
295 		err = -EMSGSIZE;
296 	}
297 
298 unlock:
299 	aead_data_wakeup(sk);
300 	release_sock(sk);
301 
302 	return err ?: copied;
303 }
304 
aead_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)305 static ssize_t aead_sendpage(struct socket *sock, struct page *page,
306 			     int offset, size_t size, int flags)
307 {
308 	struct sock *sk = sock->sk;
309 	struct alg_sock *ask = alg_sk(sk);
310 	struct aead_ctx *ctx = ask->private;
311 	struct aead_sg_list *sgl = &ctx->tsgl;
312 	int err = -EINVAL;
313 
314 	if (flags & MSG_SENDPAGE_NOTLAST)
315 		flags |= MSG_MORE;
316 
317 	if (sgl->cur >= ALG_MAX_PAGES)
318 		return -E2BIG;
319 
320 	lock_sock(sk);
321 	if (!ctx->more && ctx->used)
322 		goto unlock;
323 
324 	if (!size)
325 		goto done;
326 
327 	if (!aead_writable(sk)) {
328 		/* user space sent too much data */
329 		aead_put_sgl(sk);
330 		err = -EMSGSIZE;
331 		goto unlock;
332 	}
333 
334 	ctx->merge = 0;
335 
336 	get_page(page);
337 	sg_set_page(sgl->sg + sgl->cur, page, size, offset);
338 	sgl->cur++;
339 	ctx->used += size;
340 
341 	err = 0;
342 
343 done:
344 	ctx->more = flags & MSG_MORE;
345 	if (!ctx->more && !aead_sufficient_data(ctx)) {
346 		aead_put_sgl(sk);
347 		err = -EMSGSIZE;
348 	}
349 
350 unlock:
351 	aead_data_wakeup(sk);
352 	release_sock(sk);
353 
354 	return err ?: size;
355 }
356 
aead_recvmsg(struct socket * sock,struct msghdr * msg,size_t ignored,int flags)357 static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, int flags)
358 {
359 	struct sock *sk = sock->sk;
360 	struct alg_sock *ask = alg_sk(sk);
361 	struct aead_ctx *ctx = ask->private;
362 	unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
363 	struct aead_sg_list *sgl = &ctx->tsgl;
364 	unsigned int i = 0;
365 	int err = -EINVAL;
366 	unsigned long used = 0;
367 	size_t outlen = 0;
368 	size_t usedpages = 0;
369 	unsigned int cnt = 0;
370 
371 	/* Limit number of IOV blocks to be accessed below */
372 	if (msg->msg_iter.nr_segs > RSGL_MAX_ENTRIES)
373 		return -ENOMSG;
374 
375 	lock_sock(sk);
376 
377 	/*
378 	 * AEAD memory structure: For encryption, the tag is appended to the
379 	 * ciphertext which implies that the memory allocated for the ciphertext
380 	 * must be increased by the tag length. For decryption, the tag
381 	 * is expected to be concatenated to the ciphertext. The plaintext
382 	 * therefore has a memory size of the ciphertext minus the tag length.
383 	 *
384 	 * The memory structure for cipher operation has the following
385 	 * structure:
386 	 *	AEAD encryption input:  assoc data || plaintext
387 	 *	AEAD encryption output: cipherntext || auth tag
388 	 *	AEAD decryption input:  assoc data || ciphertext || auth tag
389 	 *	AEAD decryption output: plaintext
390 	 */
391 
392 	if (ctx->more) {
393 		err = aead_wait_for_data(sk, flags);
394 		if (err)
395 			goto unlock;
396 	}
397 
398 	used = ctx->used;
399 
400 	/*
401 	 * Make sure sufficient data is present -- note, the same check is
402 	 * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
403 	 * shall provide an information to the data sender that something is
404 	 * wrong, but they are irrelevant to maintain the kernel integrity.
405 	 * We need this check here too in case user space decides to not honor
406 	 * the error message in sendmsg/sendpage and still call recvmsg. This
407 	 * check here protects the kernel integrity.
408 	 */
409 	if (!aead_sufficient_data(ctx))
410 		goto unlock;
411 
412 	outlen = used;
413 
414 	/*
415 	 * The cipher operation input data is reduced by the associated data
416 	 * length as this data is processed separately later on.
417 	 */
418 	used -= ctx->aead_assoclen + (ctx->enc ? as : 0);
419 
420 	/* convert iovecs of output buffers into scatterlists */
421 	while (iov_iter_count(&msg->msg_iter)) {
422 		size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
423 				      (outlen - usedpages));
424 
425 		/* make one iovec available as scatterlist */
426 		err = af_alg_make_sg(&ctx->rsgl[cnt], &msg->msg_iter,
427 				     seglen);
428 		if (err < 0)
429 			goto unlock;
430 		usedpages += err;
431 		/* chain the new scatterlist with previous one */
432 		if (cnt)
433 			af_alg_link_sg(&ctx->rsgl[cnt-1], &ctx->rsgl[cnt]);
434 
435 		/* we do not need more iovecs as we have sufficient memory */
436 		if (outlen <= usedpages)
437 			break;
438 		iov_iter_advance(&msg->msg_iter, err);
439 		cnt++;
440 	}
441 
442 	err = -EINVAL;
443 	/* ensure output buffer is sufficiently large */
444 	if (usedpages < outlen)
445 		goto unlock;
446 
447 	sg_mark_end(sgl->sg + sgl->cur - 1);
448 
449 	aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->rsgl[0].sg,
450 			       used, ctx->iv);
451 	aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen);
452 
453 	err = af_alg_wait_for_completion(ctx->enc ?
454 					 crypto_aead_encrypt(&ctx->aead_req) :
455 					 crypto_aead_decrypt(&ctx->aead_req),
456 					 &ctx->completion);
457 
458 	if (err) {
459 		/* EBADMSG implies a valid cipher operation took place */
460 		if (err == -EBADMSG)
461 			aead_put_sgl(sk);
462 		goto unlock;
463 	}
464 
465 	aead_put_sgl(sk);
466 
467 	err = 0;
468 
469 unlock:
470 	for (i = 0; i < cnt; i++)
471 		af_alg_free_sg(&ctx->rsgl[i]);
472 
473 	aead_wmem_wakeup(sk);
474 	release_sock(sk);
475 
476 	return err ? err : outlen;
477 }
478 
aead_poll(struct file * file,struct socket * sock,poll_table * wait)479 static unsigned int aead_poll(struct file *file, struct socket *sock,
480 			      poll_table *wait)
481 {
482 	struct sock *sk = sock->sk;
483 	struct alg_sock *ask = alg_sk(sk);
484 	struct aead_ctx *ctx = ask->private;
485 	unsigned int mask;
486 
487 	sock_poll_wait(file, sk_sleep(sk), wait);
488 	mask = 0;
489 
490 	if (!ctx->more)
491 		mask |= POLLIN | POLLRDNORM;
492 
493 	if (aead_writable(sk))
494 		mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
495 
496 	return mask;
497 }
498 
499 static struct proto_ops algif_aead_ops = {
500 	.family		=	PF_ALG,
501 
502 	.connect	=	sock_no_connect,
503 	.socketpair	=	sock_no_socketpair,
504 	.getname	=	sock_no_getname,
505 	.ioctl		=	sock_no_ioctl,
506 	.listen		=	sock_no_listen,
507 	.shutdown	=	sock_no_shutdown,
508 	.getsockopt	=	sock_no_getsockopt,
509 	.mmap		=	sock_no_mmap,
510 	.bind		=	sock_no_bind,
511 	.accept		=	sock_no_accept,
512 	.setsockopt	=	sock_no_setsockopt,
513 
514 	.release	=	af_alg_release,
515 	.sendmsg	=	aead_sendmsg,
516 	.sendpage	=	aead_sendpage,
517 	.recvmsg	=	aead_recvmsg,
518 	.poll		=	aead_poll,
519 };
520 
aead_check_key(struct socket * sock)521 static int aead_check_key(struct socket *sock)
522 {
523 	int err = 0;
524 	struct sock *psk;
525 	struct alg_sock *pask;
526 	struct aead_tfm *tfm;
527 	struct sock *sk = sock->sk;
528 	struct alg_sock *ask = alg_sk(sk);
529 
530 	lock_sock(sk);
531 	if (!atomic_read(&ask->nokey_refcnt))
532 		goto unlock_child;
533 
534 	psk = ask->parent;
535 	pask = alg_sk(ask->parent);
536 	tfm = pask->private;
537 
538 	err = -ENOKEY;
539 	lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
540 	if (!tfm->has_key)
541 		goto unlock;
542 
543 	atomic_dec(&pask->nokey_refcnt);
544 	atomic_set(&ask->nokey_refcnt, 0);
545 
546 	err = 0;
547 
548 unlock:
549 	release_sock(psk);
550 unlock_child:
551 	release_sock(sk);
552 
553 	return err;
554 }
555 
aead_sendmsg_nokey(struct socket * sock,struct msghdr * msg,size_t size)556 static int aead_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
557 				  size_t size)
558 {
559 	int err;
560 
561 	err = aead_check_key(sock);
562 	if (err)
563 		return err;
564 
565 	return aead_sendmsg(sock, msg, size);
566 }
567 
aead_sendpage_nokey(struct socket * sock,struct page * page,int offset,size_t size,int flags)568 static ssize_t aead_sendpage_nokey(struct socket *sock, struct page *page,
569 				       int offset, size_t size, int flags)
570 {
571 	int err;
572 
573 	err = aead_check_key(sock);
574 	if (err)
575 		return err;
576 
577 	return aead_sendpage(sock, page, offset, size, flags);
578 }
579 
aead_recvmsg_nokey(struct socket * sock,struct msghdr * msg,size_t ignored,int flags)580 static int aead_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
581 				  size_t ignored, int flags)
582 {
583 	int err;
584 
585 	err = aead_check_key(sock);
586 	if (err)
587 		return err;
588 
589 	return aead_recvmsg(sock, msg, ignored, flags);
590 }
591 
592 static struct proto_ops algif_aead_ops_nokey = {
593 	.family		=	PF_ALG,
594 
595 	.connect	=	sock_no_connect,
596 	.socketpair	=	sock_no_socketpair,
597 	.getname	=	sock_no_getname,
598 	.ioctl		=	sock_no_ioctl,
599 	.listen		=	sock_no_listen,
600 	.shutdown	=	sock_no_shutdown,
601 	.getsockopt	=	sock_no_getsockopt,
602 	.mmap		=	sock_no_mmap,
603 	.bind		=	sock_no_bind,
604 	.accept		=	sock_no_accept,
605 	.setsockopt	=	sock_no_setsockopt,
606 
607 	.release	=	af_alg_release,
608 	.sendmsg	=	aead_sendmsg_nokey,
609 	.sendpage	=	aead_sendpage_nokey,
610 	.recvmsg	=	aead_recvmsg_nokey,
611 	.poll		=	aead_poll,
612 };
613 
aead_bind(const char * name,u32 type,u32 mask)614 static void *aead_bind(const char *name, u32 type, u32 mask)
615 {
616 	struct aead_tfm *tfm;
617 	struct crypto_aead *aead;
618 
619 	tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
620 	if (!tfm)
621 		return ERR_PTR(-ENOMEM);
622 
623 	aead = crypto_alloc_aead(name, type, mask);
624 	if (IS_ERR(aead)) {
625 		kfree(tfm);
626 		return ERR_CAST(aead);
627 	}
628 
629 	tfm->aead = aead;
630 
631 	return tfm;
632 }
633 
aead_release(void * private)634 static void aead_release(void *private)
635 {
636 	struct aead_tfm *tfm = private;
637 
638 	crypto_free_aead(tfm->aead);
639 	kfree(tfm);
640 }
641 
aead_setauthsize(void * private,unsigned int authsize)642 static int aead_setauthsize(void *private, unsigned int authsize)
643 {
644 	struct aead_tfm *tfm = private;
645 
646 	return crypto_aead_setauthsize(tfm->aead, authsize);
647 }
648 
aead_setkey(void * private,const u8 * key,unsigned int keylen)649 static int aead_setkey(void *private, const u8 *key, unsigned int keylen)
650 {
651 	struct aead_tfm *tfm = private;
652 	int err;
653 
654 	err = crypto_aead_setkey(tfm->aead, key, keylen);
655 	tfm->has_key = !err;
656 
657 	return err;
658 }
659 
aead_sock_destruct(struct sock * sk)660 static void aead_sock_destruct(struct sock *sk)
661 {
662 	struct alg_sock *ask = alg_sk(sk);
663 	struct aead_ctx *ctx = ask->private;
664 	unsigned int ivlen = crypto_aead_ivsize(
665 				crypto_aead_reqtfm(&ctx->aead_req));
666 
667 	aead_put_sgl(sk);
668 	sock_kzfree_s(sk, ctx->iv, ivlen);
669 	sock_kfree_s(sk, ctx, ctx->len);
670 	af_alg_release_parent(sk);
671 }
672 
aead_accept_parent_nokey(void * private,struct sock * sk)673 static int aead_accept_parent_nokey(void *private, struct sock *sk)
674 {
675 	struct aead_ctx *ctx;
676 	struct alg_sock *ask = alg_sk(sk);
677 	struct aead_tfm *tfm = private;
678 	struct crypto_aead *aead = tfm->aead;
679 	unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(aead);
680 	unsigned int ivlen = crypto_aead_ivsize(aead);
681 
682 	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
683 	if (!ctx)
684 		return -ENOMEM;
685 	memset(ctx, 0, len);
686 
687 	ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL);
688 	if (!ctx->iv) {
689 		sock_kfree_s(sk, ctx, len);
690 		return -ENOMEM;
691 	}
692 	memset(ctx->iv, 0, ivlen);
693 
694 	ctx->len = len;
695 	ctx->used = 0;
696 	ctx->more = 0;
697 	ctx->merge = 0;
698 	ctx->enc = 0;
699 	ctx->tsgl.cur = 0;
700 	ctx->aead_assoclen = 0;
701 	af_alg_init_completion(&ctx->completion);
702 	sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
703 
704 	ask->private = ctx;
705 
706 	aead_request_set_tfm(&ctx->aead_req, aead);
707 	aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
708 				  af_alg_complete, &ctx->completion);
709 
710 	sk->sk_destruct = aead_sock_destruct;
711 
712 	return 0;
713 }
714 
aead_accept_parent(void * private,struct sock * sk)715 static int aead_accept_parent(void *private, struct sock *sk)
716 {
717 	struct aead_tfm *tfm = private;
718 
719 	if (!tfm->has_key)
720 		return -ENOKEY;
721 
722 	return aead_accept_parent_nokey(private, sk);
723 }
724 
725 static const struct af_alg_type algif_type_aead = {
726 	.bind		=	aead_bind,
727 	.release	=	aead_release,
728 	.setkey		=	aead_setkey,
729 	.setauthsize	=	aead_setauthsize,
730 	.accept		=	aead_accept_parent,
731 	.accept_nokey	=	aead_accept_parent_nokey,
732 	.ops		=	&algif_aead_ops,
733 	.ops_nokey	=	&algif_aead_ops_nokey,
734 	.name		=	"aead",
735 	.owner		=	THIS_MODULE
736 };
737 
algif_aead_init(void)738 static int __init algif_aead_init(void)
739 {
740 	return af_alg_register_type(&algif_type_aead);
741 }
742 
algif_aead_exit(void)743 static void __exit algif_aead_exit(void)
744 {
745 	int err = af_alg_unregister_type(&algif_type_aead);
746 	BUG_ON(err);
747 }
748 
749 module_init(algif_aead_init);
750 module_exit(algif_aead_exit);
751 MODULE_LICENSE("GPL");
752 MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
753 MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");
754