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