Commit | Line | Data |
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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> | |
174cd4b1 | 22 | #include <linux/sched/signal.h> |
400c40cf SM |
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 | ||
83094e5e TS |
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 | unsigned int tsgls; | |
44 | char iv[]; | |
45 | }; | |
46 | ||
400c40cf SM |
47 | struct aead_ctx { |
48 | struct aead_sg_list tsgl; | |
83094e5e TS |
49 | struct aead_async_rsgl first_rsgl; |
50 | struct list_head list; | |
400c40cf SM |
51 | |
52 | void *iv; | |
53 | ||
54 | struct af_alg_completion completion; | |
55 | ||
56 | unsigned long used; | |
57 | ||
58 | unsigned int len; | |
59 | bool more; | |
60 | bool merge; | |
61 | bool enc; | |
62 | ||
63 | size_t aead_assoclen; | |
64 | struct aead_request aead_req; | |
65 | }; | |
66 | ||
67 | static inline int aead_sndbuf(struct sock *sk) | |
68 | { | |
69 | struct alg_sock *ask = alg_sk(sk); | |
70 | struct aead_ctx *ctx = ask->private; | |
71 | ||
72 | return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) - | |
73 | ctx->used, 0); | |
74 | } | |
75 | ||
76 | static inline bool aead_writable(struct sock *sk) | |
77 | { | |
78 | return PAGE_SIZE <= aead_sndbuf(sk); | |
79 | } | |
80 | ||
81 | static inline bool aead_sufficient_data(struct aead_ctx *ctx) | |
82 | { | |
83 | unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req)); | |
84 | ||
0c1e16cd SM |
85 | /* |
86 | * The minimum amount of memory needed for an AEAD cipher is | |
87 | * the AAD and in case of decryption the tag. | |
88 | */ | |
89 | return ctx->used >= ctx->aead_assoclen + (ctx->enc ? 0 : as); | |
400c40cf SM |
90 | } |
91 | ||
83094e5e TS |
92 | static void aead_reset_ctx(struct aead_ctx *ctx) |
93 | { | |
94 | struct aead_sg_list *sgl = &ctx->tsgl; | |
95 | ||
96 | sg_init_table(sgl->sg, ALG_MAX_PAGES); | |
97 | sgl->cur = 0; | |
98 | ctx->used = 0; | |
99 | ctx->more = 0; | |
100 | ctx->merge = 0; | |
101 | } | |
102 | ||
400c40cf SM |
103 | static void aead_put_sgl(struct sock *sk) |
104 | { | |
105 | struct alg_sock *ask = alg_sk(sk); | |
106 | struct aead_ctx *ctx = ask->private; | |
107 | struct aead_sg_list *sgl = &ctx->tsgl; | |
108 | struct scatterlist *sg = sgl->sg; | |
109 | unsigned int i; | |
110 | ||
111 | for (i = 0; i < sgl->cur; i++) { | |
112 | if (!sg_page(sg + i)) | |
113 | continue; | |
114 | ||
115 | put_page(sg_page(sg + i)); | |
116 | sg_assign_page(sg + i, NULL); | |
117 | } | |
83094e5e | 118 | aead_reset_ctx(ctx); |
400c40cf SM |
119 | } |
120 | ||
121 | static void aead_wmem_wakeup(struct sock *sk) | |
122 | { | |
123 | struct socket_wq *wq; | |
124 | ||
125 | if (!aead_writable(sk)) | |
126 | return; | |
127 | ||
128 | rcu_read_lock(); | |
129 | wq = rcu_dereference(sk->sk_wq); | |
1ce0bf50 | 130 | if (skwq_has_sleeper(wq)) |
400c40cf SM |
131 | wake_up_interruptible_sync_poll(&wq->wait, POLLIN | |
132 | POLLRDNORM | | |
133 | POLLRDBAND); | |
134 | sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); | |
135 | rcu_read_unlock(); | |
136 | } | |
137 | ||
138 | static int aead_wait_for_data(struct sock *sk, unsigned flags) | |
139 | { | |
d9dc8b0f | 140 | DEFINE_WAIT_FUNC(wait, woken_wake_function); |
400c40cf SM |
141 | struct alg_sock *ask = alg_sk(sk); |
142 | struct aead_ctx *ctx = ask->private; | |
143 | long timeout; | |
400c40cf SM |
144 | int err = -ERESTARTSYS; |
145 | ||
146 | if (flags & MSG_DONTWAIT) | |
147 | return -EAGAIN; | |
148 | ||
9cd3e072 | 149 | sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
d9dc8b0f | 150 | add_wait_queue(sk_sleep(sk), &wait); |
400c40cf SM |
151 | for (;;) { |
152 | if (signal_pending(current)) | |
153 | break; | |
400c40cf | 154 | timeout = MAX_SCHEDULE_TIMEOUT; |
d9dc8b0f | 155 | if (sk_wait_event(sk, &timeout, !ctx->more, &wait)) { |
400c40cf SM |
156 | err = 0; |
157 | break; | |
158 | } | |
159 | } | |
d9dc8b0f | 160 | remove_wait_queue(sk_sleep(sk), &wait); |
400c40cf | 161 | |
9cd3e072 | 162 | sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); |
400c40cf SM |
163 | |
164 | return err; | |
165 | } | |
166 | ||
167 | static void aead_data_wakeup(struct sock *sk) | |
168 | { | |
169 | struct alg_sock *ask = alg_sk(sk); | |
170 | struct aead_ctx *ctx = ask->private; | |
171 | struct socket_wq *wq; | |
172 | ||
173 | if (ctx->more) | |
174 | return; | |
175 | if (!ctx->used) | |
176 | return; | |
177 | ||
178 | rcu_read_lock(); | |
179 | wq = rcu_dereference(sk->sk_wq); | |
1ce0bf50 | 180 | if (skwq_has_sleeper(wq)) |
400c40cf SM |
181 | wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | |
182 | POLLRDNORM | | |
183 | POLLRDBAND); | |
184 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); | |
185 | rcu_read_unlock(); | |
186 | } | |
187 | ||
eccd02f3 | 188 | static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) |
400c40cf SM |
189 | { |
190 | struct sock *sk = sock->sk; | |
191 | struct alg_sock *ask = alg_sk(sk); | |
192 | struct aead_ctx *ctx = ask->private; | |
193 | unsigned ivsize = | |
194 | crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req)); | |
195 | struct aead_sg_list *sgl = &ctx->tsgl; | |
196 | struct af_alg_control con = {}; | |
197 | long copied = 0; | |
198 | bool enc = 0; | |
199 | bool init = 0; | |
200 | int err = -EINVAL; | |
201 | ||
202 | if (msg->msg_controllen) { | |
203 | err = af_alg_cmsg_send(msg, &con); | |
204 | if (err) | |
205 | return err; | |
206 | ||
207 | init = 1; | |
208 | switch (con.op) { | |
209 | case ALG_OP_ENCRYPT: | |
210 | enc = 1; | |
211 | break; | |
212 | case ALG_OP_DECRYPT: | |
213 | enc = 0; | |
214 | break; | |
215 | default: | |
216 | return -EINVAL; | |
217 | } | |
218 | ||
219 | if (con.iv && con.iv->ivlen != ivsize) | |
220 | return -EINVAL; | |
221 | } | |
222 | ||
223 | lock_sock(sk); | |
224 | if (!ctx->more && ctx->used) | |
225 | goto unlock; | |
226 | ||
227 | if (init) { | |
228 | ctx->enc = enc; | |
229 | if (con.iv) | |
230 | memcpy(ctx->iv, con.iv->iv, ivsize); | |
231 | ||
232 | ctx->aead_assoclen = con.aead_assoclen; | |
233 | } | |
234 | ||
235 | while (size) { | |
652d5b8a | 236 | size_t len = size; |
400c40cf SM |
237 | struct scatterlist *sg = NULL; |
238 | ||
239 | /* use the existing memory in an allocated page */ | |
240 | if (ctx->merge) { | |
241 | sg = sgl->sg + sgl->cur - 1; | |
242 | len = min_t(unsigned long, len, | |
243 | PAGE_SIZE - sg->offset - sg->length); | |
244 | err = memcpy_from_msg(page_address(sg_page(sg)) + | |
245 | sg->offset + sg->length, | |
246 | msg, len); | |
247 | if (err) | |
248 | goto unlock; | |
249 | ||
250 | sg->length += len; | |
251 | ctx->merge = (sg->offset + sg->length) & | |
252 | (PAGE_SIZE - 1); | |
253 | ||
254 | ctx->used += len; | |
255 | copied += len; | |
256 | size -= len; | |
257 | continue; | |
258 | } | |
259 | ||
260 | if (!aead_writable(sk)) { | |
261 | /* user space sent too much data */ | |
262 | aead_put_sgl(sk); | |
263 | err = -EMSGSIZE; | |
264 | goto unlock; | |
265 | } | |
266 | ||
267 | /* allocate a new page */ | |
268 | len = min_t(unsigned long, size, aead_sndbuf(sk)); | |
269 | while (len) { | |
652d5b8a | 270 | size_t plen = 0; |
400c40cf SM |
271 | |
272 | if (sgl->cur >= ALG_MAX_PAGES) { | |
273 | aead_put_sgl(sk); | |
274 | err = -E2BIG; | |
275 | goto unlock; | |
276 | } | |
277 | ||
278 | sg = sgl->sg + sgl->cur; | |
652d5b8a | 279 | plen = min_t(size_t, len, PAGE_SIZE); |
400c40cf SM |
280 | |
281 | sg_assign_page(sg, alloc_page(GFP_KERNEL)); | |
282 | err = -ENOMEM; | |
283 | if (!sg_page(sg)) | |
284 | goto unlock; | |
285 | ||
286 | err = memcpy_from_msg(page_address(sg_page(sg)), | |
287 | msg, plen); | |
288 | if (err) { | |
289 | __free_page(sg_page(sg)); | |
290 | sg_assign_page(sg, NULL); | |
291 | goto unlock; | |
292 | } | |
293 | ||
294 | sg->offset = 0; | |
295 | sg->length = plen; | |
296 | len -= plen; | |
297 | ctx->used += plen; | |
298 | copied += plen; | |
299 | sgl->cur++; | |
300 | size -= plen; | |
301 | ctx->merge = plen & (PAGE_SIZE - 1); | |
302 | } | |
303 | } | |
304 | ||
305 | err = 0; | |
306 | ||
307 | ctx->more = msg->msg_flags & MSG_MORE; | |
308 | if (!ctx->more && !aead_sufficient_data(ctx)) { | |
309 | aead_put_sgl(sk); | |
310 | err = -EMSGSIZE; | |
311 | } | |
312 | ||
313 | unlock: | |
314 | aead_data_wakeup(sk); | |
315 | release_sock(sk); | |
316 | ||
317 | return err ?: copied; | |
318 | } | |
319 | ||
320 | static ssize_t aead_sendpage(struct socket *sock, struct page *page, | |
321 | int offset, size_t size, int flags) | |
322 | { | |
323 | struct sock *sk = sock->sk; | |
324 | struct alg_sock *ask = alg_sk(sk); | |
325 | struct aead_ctx *ctx = ask->private; | |
326 | struct aead_sg_list *sgl = &ctx->tsgl; | |
327 | int err = -EINVAL; | |
328 | ||
329 | if (flags & MSG_SENDPAGE_NOTLAST) | |
330 | flags |= MSG_MORE; | |
331 | ||
332 | if (sgl->cur >= ALG_MAX_PAGES) | |
333 | return -E2BIG; | |
334 | ||
335 | lock_sock(sk); | |
336 | if (!ctx->more && ctx->used) | |
337 | goto unlock; | |
338 | ||
339 | if (!size) | |
340 | goto done; | |
341 | ||
342 | if (!aead_writable(sk)) { | |
343 | /* user space sent too much data */ | |
344 | aead_put_sgl(sk); | |
345 | err = -EMSGSIZE; | |
346 | goto unlock; | |
347 | } | |
348 | ||
349 | ctx->merge = 0; | |
350 | ||
351 | get_page(page); | |
352 | sg_set_page(sgl->sg + sgl->cur, page, size, offset); | |
353 | sgl->cur++; | |
354 | ctx->used += size; | |
355 | ||
356 | err = 0; | |
357 | ||
358 | done: | |
359 | ctx->more = flags & MSG_MORE; | |
360 | if (!ctx->more && !aead_sufficient_data(ctx)) { | |
361 | aead_put_sgl(sk); | |
362 | err = -EMSGSIZE; | |
363 | } | |
364 | ||
365 | unlock: | |
366 | aead_data_wakeup(sk); | |
367 | release_sock(sk); | |
368 | ||
369 | return err ?: size; | |
370 | } | |
371 | ||
83094e5e TS |
372 | #define GET_ASYM_REQ(req, tfm) (struct aead_async_req *) \ |
373 | ((char *)req + sizeof(struct aead_request) + \ | |
374 | crypto_aead_reqsize(tfm)) | |
375 | ||
376 | #define GET_REQ_SIZE(tfm) sizeof(struct aead_async_req) + \ | |
377 | crypto_aead_reqsize(tfm) + crypto_aead_ivsize(tfm) + \ | |
378 | sizeof(struct aead_request) | |
379 | ||
380 | static void aead_async_cb(struct crypto_async_request *_req, int err) | |
381 | { | |
382 | struct sock *sk = _req->data; | |
383 | struct alg_sock *ask = alg_sk(sk); | |
384 | struct aead_ctx *ctx = ask->private; | |
385 | struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req); | |
386 | struct aead_request *req = aead_request_cast(_req); | |
387 | struct aead_async_req *areq = GET_ASYM_REQ(req, tfm); | |
388 | struct scatterlist *sg = areq->tsgl; | |
389 | struct aead_async_rsgl *rsgl; | |
390 | struct kiocb *iocb = areq->iocb; | |
391 | unsigned int i, reqlen = GET_REQ_SIZE(tfm); | |
392 | ||
393 | list_for_each_entry(rsgl, &areq->list, list) { | |
394 | af_alg_free_sg(&rsgl->sgl); | |
395 | if (rsgl != &areq->first_rsgl) | |
396 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); | |
397 | } | |
398 | ||
399 | for (i = 0; i < areq->tsgls; i++) | |
400 | put_page(sg_page(sg + i)); | |
401 | ||
402 | sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls); | |
403 | sock_kfree_s(sk, req, reqlen); | |
404 | __sock_put(sk); | |
405 | iocb->ki_complete(iocb, err, err); | |
406 | } | |
407 | ||
408 | static int aead_recvmsg_async(struct socket *sock, struct msghdr *msg, | |
409 | int flags) | |
410 | { | |
411 | struct sock *sk = sock->sk; | |
412 | struct alg_sock *ask = alg_sk(sk); | |
413 | struct aead_ctx *ctx = ask->private; | |
414 | struct crypto_aead *tfm = crypto_aead_reqtfm(&ctx->aead_req); | |
415 | struct aead_async_req *areq; | |
416 | struct aead_request *req = NULL; | |
417 | struct aead_sg_list *sgl = &ctx->tsgl; | |
418 | struct aead_async_rsgl *last_rsgl = NULL, *rsgl; | |
419 | unsigned int as = crypto_aead_authsize(tfm); | |
420 | unsigned int i, reqlen = GET_REQ_SIZE(tfm); | |
421 | int err = -ENOMEM; | |
422 | unsigned long used; | |
678b5c6b | 423 | size_t outlen = 0; |
83094e5e TS |
424 | size_t usedpages = 0; |
425 | ||
426 | lock_sock(sk); | |
427 | if (ctx->more) { | |
428 | err = aead_wait_for_data(sk, flags); | |
429 | if (err) | |
430 | goto unlock; | |
431 | } | |
432 | ||
83094e5e TS |
433 | if (!aead_sufficient_data(ctx)) |
434 | goto unlock; | |
435 | ||
0c1e16cd SM |
436 | used = ctx->used; |
437 | if (ctx->enc) | |
438 | outlen = used + as; | |
439 | else | |
440 | outlen = used - as; | |
441 | ||
83094e5e TS |
442 | req = sock_kmalloc(sk, reqlen, GFP_KERNEL); |
443 | if (unlikely(!req)) | |
444 | goto unlock; | |
445 | ||
446 | areq = GET_ASYM_REQ(req, tfm); | |
447 | memset(&areq->first_rsgl, '\0', sizeof(areq->first_rsgl)); | |
448 | INIT_LIST_HEAD(&areq->list); | |
449 | areq->iocb = msg->msg_iocb; | |
450 | memcpy(areq->iv, ctx->iv, crypto_aead_ivsize(tfm)); | |
451 | aead_request_set_tfm(req, tfm); | |
452 | aead_request_set_ad(req, ctx->aead_assoclen); | |
453 | aead_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
454 | aead_async_cb, sk); | |
0c1e16cd | 455 | used -= ctx->aead_assoclen; |
83094e5e TS |
456 | |
457 | /* take over all tx sgls from ctx */ | |
5937d81a SM |
458 | areq->tsgl = sock_kmalloc(sk, |
459 | sizeof(*areq->tsgl) * max_t(u32, sgl->cur, 1), | |
83094e5e TS |
460 | GFP_KERNEL); |
461 | if (unlikely(!areq->tsgl)) | |
462 | goto free; | |
463 | ||
5937d81a | 464 | sg_init_table(areq->tsgl, max_t(u32, sgl->cur, 1)); |
83094e5e TS |
465 | for (i = 0; i < sgl->cur; i++) |
466 | sg_set_page(&areq->tsgl[i], sg_page(&sgl->sg[i]), | |
467 | sgl->sg[i].length, sgl->sg[i].offset); | |
468 | ||
469 | areq->tsgls = sgl->cur; | |
470 | ||
471 | /* create rx sgls */ | |
0c1e16cd | 472 | while (outlen > usedpages && iov_iter_count(&msg->msg_iter)) { |
83094e5e TS |
473 | size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter), |
474 | (outlen - usedpages)); | |
475 | ||
476 | if (list_empty(&areq->list)) { | |
477 | rsgl = &areq->first_rsgl; | |
478 | ||
479 | } else { | |
480 | rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); | |
481 | if (unlikely(!rsgl)) { | |
482 | err = -ENOMEM; | |
483 | goto free; | |
484 | } | |
485 | } | |
486 | rsgl->sgl.npages = 0; | |
487 | list_add_tail(&rsgl->list, &areq->list); | |
488 | ||
489 | /* make one iovec available as scatterlist */ | |
490 | err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); | |
491 | if (err < 0) | |
492 | goto free; | |
493 | ||
494 | usedpages += err; | |
495 | ||
496 | /* chain the new scatterlist with previous one */ | |
497 | if (last_rsgl) | |
498 | af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl); | |
499 | ||
500 | last_rsgl = rsgl; | |
501 | ||
83094e5e TS |
502 | iov_iter_advance(&msg->msg_iter, err); |
503 | } | |
0c1e16cd | 504 | |
83094e5e | 505 | /* ensure output buffer is sufficiently large */ |
0c1e16cd SM |
506 | if (usedpages < outlen) { |
507 | err = -EINVAL; | |
508 | goto unlock; | |
509 | } | |
83094e5e TS |
510 | |
511 | aead_request_set_crypt(req, areq->tsgl, areq->first_rsgl.sgl.sg, used, | |
512 | areq->iv); | |
513 | err = ctx->enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); | |
514 | if (err) { | |
515 | if (err == -EINPROGRESS) { | |
516 | sock_hold(sk); | |
517 | err = -EIOCBQUEUED; | |
518 | aead_reset_ctx(ctx); | |
519 | goto unlock; | |
520 | } else if (err == -EBADMSG) { | |
521 | aead_put_sgl(sk); | |
522 | } | |
523 | goto free; | |
524 | } | |
525 | aead_put_sgl(sk); | |
526 | ||
527 | free: | |
528 | list_for_each_entry(rsgl, &areq->list, list) { | |
529 | af_alg_free_sg(&rsgl->sgl); | |
530 | if (rsgl != &areq->first_rsgl) | |
531 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); | |
532 | } | |
533 | if (areq->tsgl) | |
534 | sock_kfree_s(sk, areq->tsgl, sizeof(*areq->tsgl) * areq->tsgls); | |
535 | if (req) | |
536 | sock_kfree_s(sk, req, reqlen); | |
537 | unlock: | |
538 | aead_wmem_wakeup(sk); | |
539 | release_sock(sk); | |
540 | return err ? err : outlen; | |
541 | } | |
542 | ||
543 | static int aead_recvmsg_sync(struct socket *sock, struct msghdr *msg, int flags) | |
400c40cf SM |
544 | { |
545 | struct sock *sk = sock->sk; | |
546 | struct alg_sock *ask = alg_sk(sk); | |
547 | struct aead_ctx *ctx = ask->private; | |
400c40cf SM |
548 | unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req)); |
549 | struct aead_sg_list *sgl = &ctx->tsgl; | |
83094e5e TS |
550 | struct aead_async_rsgl *last_rsgl = NULL; |
551 | struct aead_async_rsgl *rsgl, *tmp; | |
400c40cf SM |
552 | int err = -EINVAL; |
553 | unsigned long used = 0; | |
554 | size_t outlen = 0; | |
555 | size_t usedpages = 0; | |
400c40cf SM |
556 | |
557 | lock_sock(sk); | |
558 | ||
559 | /* | |
3f692d5f SM |
560 | * Please see documentation of aead_request_set_crypt for the |
561 | * description of the AEAD memory structure expected from the caller. | |
400c40cf SM |
562 | */ |
563 | ||
564 | if (ctx->more) { | |
565 | err = aead_wait_for_data(sk, flags); | |
566 | if (err) | |
567 | goto unlock; | |
568 | } | |
569 | ||
0c1e16cd | 570 | /* data length provided by caller via sendmsg/sendpage */ |
400c40cf SM |
571 | used = ctx->used; |
572 | ||
573 | /* | |
574 | * Make sure sufficient data is present -- note, the same check is | |
575 | * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg | |
576 | * shall provide an information to the data sender that something is | |
577 | * wrong, but they are irrelevant to maintain the kernel integrity. | |
578 | * We need this check here too in case user space decides to not honor | |
579 | * the error message in sendmsg/sendpage and still call recvmsg. This | |
580 | * check here protects the kernel integrity. | |
581 | */ | |
582 | if (!aead_sufficient_data(ctx)) | |
583 | goto unlock; | |
584 | ||
0c1e16cd SM |
585 | /* |
586 | * Calculate the minimum output buffer size holding the result of the | |
587 | * cipher operation. When encrypting data, the receiving buffer is | |
588 | * larger by the tag length compared to the input buffer as the | |
589 | * encryption operation generates the tag. For decryption, the input | |
590 | * buffer provides the tag which is consumed resulting in only the | |
591 | * plaintext without a buffer for the tag returned to the caller. | |
592 | */ | |
593 | if (ctx->enc) | |
594 | outlen = used + as; | |
595 | else | |
596 | outlen = used - as; | |
19fa7752 | 597 | |
400c40cf SM |
598 | /* |
599 | * The cipher operation input data is reduced by the associated data | |
600 | * length as this data is processed separately later on. | |
601 | */ | |
0c1e16cd | 602 | used -= ctx->aead_assoclen; |
400c40cf SM |
603 | |
604 | /* convert iovecs of output buffers into scatterlists */ | |
0c1e16cd | 605 | while (outlen > usedpages && iov_iter_count(&msg->msg_iter)) { |
400c40cf SM |
606 | size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter), |
607 | (outlen - usedpages)); | |
608 | ||
83094e5e TS |
609 | if (list_empty(&ctx->list)) { |
610 | rsgl = &ctx->first_rsgl; | |
611 | } else { | |
612 | rsgl = sock_kmalloc(sk, sizeof(*rsgl), GFP_KERNEL); | |
613 | if (unlikely(!rsgl)) { | |
614 | err = -ENOMEM; | |
615 | goto unlock; | |
616 | } | |
617 | } | |
618 | rsgl->sgl.npages = 0; | |
619 | list_add_tail(&rsgl->list, &ctx->list); | |
620 | ||
400c40cf | 621 | /* make one iovec available as scatterlist */ |
83094e5e | 622 | err = af_alg_make_sg(&rsgl->sgl, &msg->msg_iter, seglen); |
400c40cf SM |
623 | if (err < 0) |
624 | goto unlock; | |
625 | usedpages += err; | |
7b2a18e0 | 626 | /* chain the new scatterlist with previous one */ |
83094e5e TS |
627 | if (last_rsgl) |
628 | af_alg_link_sg(&last_rsgl->sgl, &rsgl->sgl); | |
629 | ||
630 | last_rsgl = rsgl; | |
7b2a18e0 | 631 | |
400c40cf | 632 | iov_iter_advance(&msg->msg_iter, err); |
400c40cf SM |
633 | } |
634 | ||
400c40cf | 635 | /* ensure output buffer is sufficiently large */ |
0c1e16cd SM |
636 | if (usedpages < outlen) { |
637 | err = -EINVAL; | |
400c40cf | 638 | goto unlock; |
0c1e16cd | 639 | } |
400c40cf | 640 | |
19fa7752 | 641 | sg_mark_end(sgl->sg + sgl->cur - 1); |
83094e5e | 642 | aead_request_set_crypt(&ctx->aead_req, sgl->sg, ctx->first_rsgl.sgl.sg, |
19fa7752 HX |
643 | used, ctx->iv); |
644 | aead_request_set_ad(&ctx->aead_req, ctx->aead_assoclen); | |
400c40cf SM |
645 | |
646 | err = af_alg_wait_for_completion(ctx->enc ? | |
647 | crypto_aead_encrypt(&ctx->aead_req) : | |
648 | crypto_aead_decrypt(&ctx->aead_req), | |
649 | &ctx->completion); | |
650 | ||
651 | if (err) { | |
652 | /* EBADMSG implies a valid cipher operation took place */ | |
653 | if (err == -EBADMSG) | |
654 | aead_put_sgl(sk); | |
83094e5e | 655 | |
400c40cf SM |
656 | goto unlock; |
657 | } | |
658 | ||
659 | aead_put_sgl(sk); | |
400c40cf SM |
660 | err = 0; |
661 | ||
662 | unlock: | |
83094e5e TS |
663 | list_for_each_entry_safe(rsgl, tmp, &ctx->list, list) { |
664 | af_alg_free_sg(&rsgl->sgl); | |
0b529f14 | 665 | list_del(&rsgl->list); |
83094e5e TS |
666 | if (rsgl != &ctx->first_rsgl) |
667 | sock_kfree_s(sk, rsgl, sizeof(*rsgl)); | |
83094e5e TS |
668 | } |
669 | INIT_LIST_HEAD(&ctx->list); | |
400c40cf SM |
670 | aead_wmem_wakeup(sk); |
671 | release_sock(sk); | |
672 | ||
673 | return err ? err : outlen; | |
674 | } | |
675 | ||
83094e5e TS |
676 | static int aead_recvmsg(struct socket *sock, struct msghdr *msg, size_t ignored, |
677 | int flags) | |
678 | { | |
679 | return (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) ? | |
680 | aead_recvmsg_async(sock, msg, flags) : | |
681 | aead_recvmsg_sync(sock, msg, flags); | |
682 | } | |
683 | ||
400c40cf SM |
684 | static unsigned int aead_poll(struct file *file, struct socket *sock, |
685 | poll_table *wait) | |
686 | { | |
687 | struct sock *sk = sock->sk; | |
688 | struct alg_sock *ask = alg_sk(sk); | |
689 | struct aead_ctx *ctx = ask->private; | |
690 | unsigned int mask; | |
691 | ||
692 | sock_poll_wait(file, sk_sleep(sk), wait); | |
693 | mask = 0; | |
694 | ||
695 | if (!ctx->more) | |
696 | mask |= POLLIN | POLLRDNORM; | |
697 | ||
698 | if (aead_writable(sk)) | |
699 | mask |= POLLOUT | POLLWRNORM | POLLWRBAND; | |
700 | ||
701 | return mask; | |
702 | } | |
703 | ||
704 | static struct proto_ops algif_aead_ops = { | |
705 | .family = PF_ALG, | |
706 | ||
707 | .connect = sock_no_connect, | |
708 | .socketpair = sock_no_socketpair, | |
709 | .getname = sock_no_getname, | |
710 | .ioctl = sock_no_ioctl, | |
711 | .listen = sock_no_listen, | |
712 | .shutdown = sock_no_shutdown, | |
713 | .getsockopt = sock_no_getsockopt, | |
714 | .mmap = sock_no_mmap, | |
715 | .bind = sock_no_bind, | |
716 | .accept = sock_no_accept, | |
717 | .setsockopt = sock_no_setsockopt, | |
718 | ||
719 | .release = af_alg_release, | |
720 | .sendmsg = aead_sendmsg, | |
721 | .sendpage = aead_sendpage, | |
722 | .recvmsg = aead_recvmsg, | |
723 | .poll = aead_poll, | |
724 | }; | |
725 | ||
726 | static void *aead_bind(const char *name, u32 type, u32 mask) | |
727 | { | |
5e4b8c1f | 728 | return crypto_alloc_aead(name, type, mask); |
400c40cf SM |
729 | } |
730 | ||
731 | static void aead_release(void *private) | |
732 | { | |
733 | crypto_free_aead(private); | |
734 | } | |
735 | ||
736 | static int aead_setauthsize(void *private, unsigned int authsize) | |
737 | { | |
738 | return crypto_aead_setauthsize(private, authsize); | |
739 | } | |
740 | ||
741 | static int aead_setkey(void *private, const u8 *key, unsigned int keylen) | |
742 | { | |
743 | return crypto_aead_setkey(private, key, keylen); | |
744 | } | |
745 | ||
746 | static void aead_sock_destruct(struct sock *sk) | |
747 | { | |
748 | struct alg_sock *ask = alg_sk(sk); | |
749 | struct aead_ctx *ctx = ask->private; | |
750 | unsigned int ivlen = crypto_aead_ivsize( | |
751 | crypto_aead_reqtfm(&ctx->aead_req)); | |
752 | ||
83094e5e | 753 | WARN_ON(atomic_read(&sk->sk_refcnt) != 0); |
400c40cf SM |
754 | aead_put_sgl(sk); |
755 | sock_kzfree_s(sk, ctx->iv, ivlen); | |
756 | sock_kfree_s(sk, ctx, ctx->len); | |
757 | af_alg_release_parent(sk); | |
758 | } | |
759 | ||
760 | static int aead_accept_parent(void *private, struct sock *sk) | |
761 | { | |
762 | struct aead_ctx *ctx; | |
763 | struct alg_sock *ask = alg_sk(sk); | |
764 | unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(private); | |
765 | unsigned int ivlen = crypto_aead_ivsize(private); | |
766 | ||
767 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
768 | if (!ctx) | |
769 | return -ENOMEM; | |
770 | memset(ctx, 0, len); | |
771 | ||
772 | ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL); | |
773 | if (!ctx->iv) { | |
774 | sock_kfree_s(sk, ctx, len); | |
775 | return -ENOMEM; | |
776 | } | |
777 | memset(ctx->iv, 0, ivlen); | |
778 | ||
779 | ctx->len = len; | |
780 | ctx->used = 0; | |
781 | ctx->more = 0; | |
782 | ctx->merge = 0; | |
783 | ctx->enc = 0; | |
784 | ctx->tsgl.cur = 0; | |
785 | ctx->aead_assoclen = 0; | |
786 | af_alg_init_completion(&ctx->completion); | |
787 | sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES); | |
83094e5e | 788 | INIT_LIST_HEAD(&ctx->list); |
400c40cf SM |
789 | |
790 | ask->private = ctx; | |
791 | ||
792 | aead_request_set_tfm(&ctx->aead_req, private); | |
793 | aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
794 | af_alg_complete, &ctx->completion); | |
795 | ||
796 | sk->sk_destruct = aead_sock_destruct; | |
797 | ||
798 | return 0; | |
799 | } | |
800 | ||
801 | static const struct af_alg_type algif_type_aead = { | |
802 | .bind = aead_bind, | |
803 | .release = aead_release, | |
804 | .setkey = aead_setkey, | |
805 | .setauthsize = aead_setauthsize, | |
806 | .accept = aead_accept_parent, | |
807 | .ops = &algif_aead_ops, | |
808 | .name = "aead", | |
809 | .owner = THIS_MODULE | |
810 | }; | |
811 | ||
812 | static int __init algif_aead_init(void) | |
813 | { | |
814 | return af_alg_register_type(&algif_type_aead); | |
815 | } | |
816 | ||
817 | static void __exit algif_aead_exit(void) | |
818 | { | |
819 | int err = af_alg_unregister_type(&algif_type_aead); | |
820 | BUG_ON(err); | |
821 | } | |
822 | ||
823 | module_init(algif_aead_init); | |
824 | module_exit(algif_aead_exit); | |
825 | MODULE_LICENSE("GPL"); | |
826 | MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>"); | |
827 | MODULE_DESCRIPTION("AEAD kernel crypto API user space interface"); |