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1 | /* | |
2 | * algif_hash: User-space interface for hash algorithms | |
3 | * | |
4 | * This file provides the user-space API for hash algorithms. | |
5 | * | |
6 | * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify it | |
9 | * under the terms of the GNU General Public License as published by the Free | |
10 | * Software Foundation; either version 2 of the License, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include <crypto/hash.h> | |
16 | #include <crypto/if_alg.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/mm.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/net.h> | |
22 | #include <net/sock.h> | |
23 | ||
24 | struct hash_ctx { | |
25 | struct af_alg_sgl sgl; | |
26 | ||
27 | u8 *result; | |
28 | ||
29 | struct crypto_wait wait; | |
30 | ||
31 | unsigned int len; | |
32 | bool more; | |
33 | ||
34 | struct ahash_request req; | |
35 | }; | |
36 | ||
37 | static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx) | |
38 | { | |
39 | unsigned ds; | |
40 | ||
41 | if (ctx->result) | |
42 | return 0; | |
43 | ||
44 | ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); | |
45 | ||
46 | ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL); | |
47 | if (!ctx->result) | |
48 | return -ENOMEM; | |
49 | ||
50 | memset(ctx->result, 0, ds); | |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
55 | static void hash_free_result(struct sock *sk, struct hash_ctx *ctx) | |
56 | { | |
57 | unsigned ds; | |
58 | ||
59 | if (!ctx->result) | |
60 | return; | |
61 | ||
62 | ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); | |
63 | ||
64 | sock_kzfree_s(sk, ctx->result, ds); | |
65 | ctx->result = NULL; | |
66 | } | |
67 | ||
68 | static int hash_sendmsg(struct socket *sock, struct msghdr *msg, | |
69 | size_t ignored) | |
70 | { | |
71 | int limit = ALG_MAX_PAGES * PAGE_SIZE; | |
72 | struct sock *sk = sock->sk; | |
73 | struct alg_sock *ask = alg_sk(sk); | |
74 | struct hash_ctx *ctx = ask->private; | |
75 | long copied = 0; | |
76 | int err; | |
77 | ||
78 | if (limit > sk->sk_sndbuf) | |
79 | limit = sk->sk_sndbuf; | |
80 | ||
81 | lock_sock(sk); | |
82 | if (!ctx->more) { | |
83 | if ((msg->msg_flags & MSG_MORE)) | |
84 | hash_free_result(sk, ctx); | |
85 | ||
86 | err = crypto_wait_req(crypto_ahash_init(&ctx->req), &ctx->wait); | |
87 | if (err) | |
88 | goto unlock; | |
89 | } | |
90 | ||
91 | ctx->more = 0; | |
92 | ||
93 | while (msg_data_left(msg)) { | |
94 | int len = msg_data_left(msg); | |
95 | ||
96 | if (len > limit) | |
97 | len = limit; | |
98 | ||
99 | len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len); | |
100 | if (len < 0) { | |
101 | err = copied ? 0 : len; | |
102 | goto unlock; | |
103 | } | |
104 | ||
105 | ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len); | |
106 | ||
107 | err = crypto_wait_req(crypto_ahash_update(&ctx->req), | |
108 | &ctx->wait); | |
109 | af_alg_free_sg(&ctx->sgl); | |
110 | if (err) | |
111 | goto unlock; | |
112 | ||
113 | copied += len; | |
114 | iov_iter_advance(&msg->msg_iter, len); | |
115 | } | |
116 | ||
117 | err = 0; | |
118 | ||
119 | ctx->more = msg->msg_flags & MSG_MORE; | |
120 | if (!ctx->more) { | |
121 | err = hash_alloc_result(sk, ctx); | |
122 | if (err) | |
123 | goto unlock; | |
124 | ||
125 | ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); | |
126 | err = crypto_wait_req(crypto_ahash_final(&ctx->req), | |
127 | &ctx->wait); | |
128 | } | |
129 | ||
130 | unlock: | |
131 | release_sock(sk); | |
132 | ||
133 | return err ?: copied; | |
134 | } | |
135 | ||
136 | static ssize_t hash_sendpage(struct socket *sock, struct page *page, | |
137 | int offset, size_t size, int flags) | |
138 | { | |
139 | struct sock *sk = sock->sk; | |
140 | struct alg_sock *ask = alg_sk(sk); | |
141 | struct hash_ctx *ctx = ask->private; | |
142 | int err; | |
143 | ||
144 | if (flags & MSG_SENDPAGE_NOTLAST) | |
145 | flags |= MSG_MORE; | |
146 | ||
147 | lock_sock(sk); | |
148 | sg_init_table(ctx->sgl.sg, 1); | |
149 | sg_set_page(ctx->sgl.sg, page, size, offset); | |
150 | ||
151 | if (!(flags & MSG_MORE)) { | |
152 | err = hash_alloc_result(sk, ctx); | |
153 | if (err) | |
154 | goto unlock; | |
155 | } else if (!ctx->more) | |
156 | hash_free_result(sk, ctx); | |
157 | ||
158 | ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size); | |
159 | ||
160 | if (!(flags & MSG_MORE)) { | |
161 | if (ctx->more) | |
162 | err = crypto_ahash_finup(&ctx->req); | |
163 | else | |
164 | err = crypto_ahash_digest(&ctx->req); | |
165 | } else { | |
166 | if (!ctx->more) { | |
167 | err = crypto_ahash_init(&ctx->req); | |
168 | err = crypto_wait_req(err, &ctx->wait); | |
169 | if (err) | |
170 | goto unlock; | |
171 | } | |
172 | ||
173 | err = crypto_ahash_update(&ctx->req); | |
174 | } | |
175 | ||
176 | err = crypto_wait_req(err, &ctx->wait); | |
177 | if (err) | |
178 | goto unlock; | |
179 | ||
180 | ctx->more = flags & MSG_MORE; | |
181 | ||
182 | unlock: | |
183 | release_sock(sk); | |
184 | ||
185 | return err ?: size; | |
186 | } | |
187 | ||
188 | static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, | |
189 | int flags) | |
190 | { | |
191 | struct sock *sk = sock->sk; | |
192 | struct alg_sock *ask = alg_sk(sk); | |
193 | struct hash_ctx *ctx = ask->private; | |
194 | unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)); | |
195 | bool result; | |
196 | int err; | |
197 | ||
198 | if (len > ds) | |
199 | len = ds; | |
200 | else if (len < ds) | |
201 | msg->msg_flags |= MSG_TRUNC; | |
202 | ||
203 | lock_sock(sk); | |
204 | result = ctx->result; | |
205 | err = hash_alloc_result(sk, ctx); | |
206 | if (err) | |
207 | goto unlock; | |
208 | ||
209 | ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); | |
210 | ||
211 | if (!result && !ctx->more) { | |
212 | err = crypto_wait_req(crypto_ahash_init(&ctx->req), | |
213 | &ctx->wait); | |
214 | if (err) | |
215 | goto unlock; | |
216 | } | |
217 | ||
218 | if (!result || ctx->more) { | |
219 | ctx->more = 0; | |
220 | err = crypto_wait_req(crypto_ahash_final(&ctx->req), | |
221 | &ctx->wait); | |
222 | if (err) | |
223 | goto unlock; | |
224 | } | |
225 | ||
226 | err = memcpy_to_msg(msg, ctx->result, len); | |
227 | ||
228 | unlock: | |
229 | hash_free_result(sk, ctx); | |
230 | release_sock(sk); | |
231 | ||
232 | return err ?: len; | |
233 | } | |
234 | ||
235 | static int hash_accept(struct socket *sock, struct socket *newsock, int flags, | |
236 | bool kern) | |
237 | { | |
238 | struct sock *sk = sock->sk; | |
239 | struct alg_sock *ask = alg_sk(sk); | |
240 | struct hash_ctx *ctx = ask->private; | |
241 | struct ahash_request *req = &ctx->req; | |
242 | char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req)) ? : 1]; | |
243 | struct sock *sk2; | |
244 | struct alg_sock *ask2; | |
245 | struct hash_ctx *ctx2; | |
246 | bool more; | |
247 | int err; | |
248 | ||
249 | lock_sock(sk); | |
250 | more = ctx->more; | |
251 | err = more ? crypto_ahash_export(req, state) : 0; | |
252 | release_sock(sk); | |
253 | ||
254 | if (err) | |
255 | return err; | |
256 | ||
257 | err = af_alg_accept(ask->parent, newsock, kern); | |
258 | if (err) | |
259 | return err; | |
260 | ||
261 | sk2 = newsock->sk; | |
262 | ask2 = alg_sk(sk2); | |
263 | ctx2 = ask2->private; | |
264 | ctx2->more = more; | |
265 | ||
266 | if (!more) | |
267 | return err; | |
268 | ||
269 | err = crypto_ahash_import(&ctx2->req, state); | |
270 | if (err) { | |
271 | sock_orphan(sk2); | |
272 | sock_put(sk2); | |
273 | } | |
274 | ||
275 | return err; | |
276 | } | |
277 | ||
278 | static struct proto_ops algif_hash_ops = { | |
279 | .family = PF_ALG, | |
280 | ||
281 | .connect = sock_no_connect, | |
282 | .socketpair = sock_no_socketpair, | |
283 | .getname = sock_no_getname, | |
284 | .ioctl = sock_no_ioctl, | |
285 | .listen = sock_no_listen, | |
286 | .shutdown = sock_no_shutdown, | |
287 | .getsockopt = sock_no_getsockopt, | |
288 | .mmap = sock_no_mmap, | |
289 | .bind = sock_no_bind, | |
290 | .setsockopt = sock_no_setsockopt, | |
291 | .poll = sock_no_poll, | |
292 | ||
293 | .release = af_alg_release, | |
294 | .sendmsg = hash_sendmsg, | |
295 | .sendpage = hash_sendpage, | |
296 | .recvmsg = hash_recvmsg, | |
297 | .accept = hash_accept, | |
298 | }; | |
299 | ||
300 | static int hash_check_key(struct socket *sock) | |
301 | { | |
302 | int err = 0; | |
303 | struct sock *psk; | |
304 | struct alg_sock *pask; | |
305 | struct crypto_ahash *tfm; | |
306 | struct sock *sk = sock->sk; | |
307 | struct alg_sock *ask = alg_sk(sk); | |
308 | ||
309 | lock_sock(sk); | |
310 | if (ask->refcnt) | |
311 | goto unlock_child; | |
312 | ||
313 | psk = ask->parent; | |
314 | pask = alg_sk(ask->parent); | |
315 | tfm = pask->private; | |
316 | ||
317 | err = -ENOKEY; | |
318 | lock_sock_nested(psk, SINGLE_DEPTH_NESTING); | |
319 | if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) | |
320 | goto unlock; | |
321 | ||
322 | if (!pask->refcnt++) | |
323 | sock_hold(psk); | |
324 | ||
325 | ask->refcnt = 1; | |
326 | sock_put(psk); | |
327 | ||
328 | err = 0; | |
329 | ||
330 | unlock: | |
331 | release_sock(psk); | |
332 | unlock_child: | |
333 | release_sock(sk); | |
334 | ||
335 | return err; | |
336 | } | |
337 | ||
338 | static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg, | |
339 | size_t size) | |
340 | { | |
341 | int err; | |
342 | ||
343 | err = hash_check_key(sock); | |
344 | if (err) | |
345 | return err; | |
346 | ||
347 | return hash_sendmsg(sock, msg, size); | |
348 | } | |
349 | ||
350 | static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page, | |
351 | int offset, size_t size, int flags) | |
352 | { | |
353 | int err; | |
354 | ||
355 | err = hash_check_key(sock); | |
356 | if (err) | |
357 | return err; | |
358 | ||
359 | return hash_sendpage(sock, page, offset, size, flags); | |
360 | } | |
361 | ||
362 | static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg, | |
363 | size_t ignored, int flags) | |
364 | { | |
365 | int err; | |
366 | ||
367 | err = hash_check_key(sock); | |
368 | if (err) | |
369 | return err; | |
370 | ||
371 | return hash_recvmsg(sock, msg, ignored, flags); | |
372 | } | |
373 | ||
374 | static int hash_accept_nokey(struct socket *sock, struct socket *newsock, | |
375 | int flags, bool kern) | |
376 | { | |
377 | int err; | |
378 | ||
379 | err = hash_check_key(sock); | |
380 | if (err) | |
381 | return err; | |
382 | ||
383 | return hash_accept(sock, newsock, flags, kern); | |
384 | } | |
385 | ||
386 | static struct proto_ops algif_hash_ops_nokey = { | |
387 | .family = PF_ALG, | |
388 | ||
389 | .connect = sock_no_connect, | |
390 | .socketpair = sock_no_socketpair, | |
391 | .getname = sock_no_getname, | |
392 | .ioctl = sock_no_ioctl, | |
393 | .listen = sock_no_listen, | |
394 | .shutdown = sock_no_shutdown, | |
395 | .getsockopt = sock_no_getsockopt, | |
396 | .mmap = sock_no_mmap, | |
397 | .bind = sock_no_bind, | |
398 | .setsockopt = sock_no_setsockopt, | |
399 | .poll = sock_no_poll, | |
400 | ||
401 | .release = af_alg_release, | |
402 | .sendmsg = hash_sendmsg_nokey, | |
403 | .sendpage = hash_sendpage_nokey, | |
404 | .recvmsg = hash_recvmsg_nokey, | |
405 | .accept = hash_accept_nokey, | |
406 | }; | |
407 | ||
408 | static void *hash_bind(const char *name, u32 type, u32 mask) | |
409 | { | |
410 | return crypto_alloc_ahash(name, type, mask); | |
411 | } | |
412 | ||
413 | static void hash_release(void *private) | |
414 | { | |
415 | crypto_free_ahash(private); | |
416 | } | |
417 | ||
418 | static int hash_setkey(void *private, const u8 *key, unsigned int keylen) | |
419 | { | |
420 | return crypto_ahash_setkey(private, key, keylen); | |
421 | } | |
422 | ||
423 | static void hash_sock_destruct(struct sock *sk) | |
424 | { | |
425 | struct alg_sock *ask = alg_sk(sk); | |
426 | struct hash_ctx *ctx = ask->private; | |
427 | ||
428 | hash_free_result(sk, ctx); | |
429 | sock_kfree_s(sk, ctx, ctx->len); | |
430 | af_alg_release_parent(sk); | |
431 | } | |
432 | ||
433 | static int hash_accept_parent_nokey(void *private, struct sock *sk) | |
434 | { | |
435 | struct crypto_ahash *tfm = private; | |
436 | struct alg_sock *ask = alg_sk(sk); | |
437 | struct hash_ctx *ctx; | |
438 | unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm); | |
439 | ||
440 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
441 | if (!ctx) | |
442 | return -ENOMEM; | |
443 | ||
444 | ctx->result = NULL; | |
445 | ctx->len = len; | |
446 | ctx->more = 0; | |
447 | crypto_init_wait(&ctx->wait); | |
448 | ||
449 | ask->private = ctx; | |
450 | ||
451 | ahash_request_set_tfm(&ctx->req, tfm); | |
452 | ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, | |
453 | crypto_req_done, &ctx->wait); | |
454 | ||
455 | sk->sk_destruct = hash_sock_destruct; | |
456 | ||
457 | return 0; | |
458 | } | |
459 | ||
460 | static int hash_accept_parent(void *private, struct sock *sk) | |
461 | { | |
462 | struct crypto_ahash *tfm = private; | |
463 | ||
464 | if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) | |
465 | return -ENOKEY; | |
466 | ||
467 | return hash_accept_parent_nokey(private, sk); | |
468 | } | |
469 | ||
470 | static const struct af_alg_type algif_type_hash = { | |
471 | .bind = hash_bind, | |
472 | .release = hash_release, | |
473 | .setkey = hash_setkey, | |
474 | .accept = hash_accept_parent, | |
475 | .accept_nokey = hash_accept_parent_nokey, | |
476 | .ops = &algif_hash_ops, | |
477 | .ops_nokey = &algif_hash_ops_nokey, | |
478 | .name = "hash", | |
479 | .owner = THIS_MODULE | |
480 | }; | |
481 | ||
482 | static int __init algif_hash_init(void) | |
483 | { | |
484 | return af_alg_register_type(&algif_type_hash); | |
485 | } | |
486 | ||
487 | static void __exit algif_hash_exit(void) | |
488 | { | |
489 | int err = af_alg_unregister_type(&algif_type_hash); | |
490 | BUG_ON(err); | |
491 | } | |
492 | ||
493 | module_init(algif_hash_init); | |
494 | module_exit(algif_hash_exit); | |
495 | MODULE_LICENSE("GPL"); |