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 af_alg_completion completion;
30
31 unsigned int len;
32 bool more;
33
34 struct ahash_request req;
35 };
36
hash_alloc_result(struct sock * sk,struct hash_ctx * ctx)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
hash_free_result(struct sock * sk,struct hash_ctx * ctx)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
hash_sendmsg(struct socket * sock,struct msghdr * msg,size_t ignored)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 = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
87 &ctx->completion);
88 if (err)
89 goto unlock;
90 }
91
92 ctx->more = 0;
93
94 while (msg_data_left(msg)) {
95 int len = msg_data_left(msg);
96
97 if (len > limit)
98 len = limit;
99
100 len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
101 if (len < 0) {
102 err = copied ? 0 : len;
103 goto unlock;
104 }
105
106 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
107
108 err = af_alg_wait_for_completion(crypto_ahash_update(&ctx->req),
109 &ctx->completion);
110 af_alg_free_sg(&ctx->sgl);
111 if (err)
112 goto unlock;
113
114 copied += len;
115 iov_iter_advance(&msg->msg_iter, len);
116 }
117
118 err = 0;
119
120 ctx->more = msg->msg_flags & MSG_MORE;
121 if (!ctx->more) {
122 err = hash_alloc_result(sk, ctx);
123 if (err)
124 goto unlock;
125
126 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
127 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
128 &ctx->completion);
129 }
130
131 unlock:
132 release_sock(sk);
133
134 return err ?: copied;
135 }
136
hash_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)137 static ssize_t hash_sendpage(struct socket *sock, struct page *page,
138 int offset, size_t size, int flags)
139 {
140 struct sock *sk = sock->sk;
141 struct alg_sock *ask = alg_sk(sk);
142 struct hash_ctx *ctx = ask->private;
143 int err;
144
145 if (flags & MSG_SENDPAGE_NOTLAST)
146 flags |= MSG_MORE;
147
148 lock_sock(sk);
149 sg_init_table(ctx->sgl.sg, 1);
150 sg_set_page(ctx->sgl.sg, page, size, offset);
151
152 if (!(flags & MSG_MORE)) {
153 err = hash_alloc_result(sk, ctx);
154 if (err)
155 goto unlock;
156 } else if (!ctx->more)
157 hash_free_result(sk, ctx);
158
159 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
160
161 if (!(flags & MSG_MORE)) {
162 if (ctx->more)
163 err = crypto_ahash_finup(&ctx->req);
164 else
165 err = crypto_ahash_digest(&ctx->req);
166 } else {
167 if (!ctx->more) {
168 err = crypto_ahash_init(&ctx->req);
169 err = af_alg_wait_for_completion(err, &ctx->completion);
170 if (err)
171 goto unlock;
172 }
173
174 err = crypto_ahash_update(&ctx->req);
175 }
176
177 err = af_alg_wait_for_completion(err, &ctx->completion);
178 if (err)
179 goto unlock;
180
181 ctx->more = flags & MSG_MORE;
182
183 unlock:
184 release_sock(sk);
185
186 return err ?: size;
187 }
188
hash_recvmsg(struct socket * sock,struct msghdr * msg,size_t len,int flags)189 static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
190 int flags)
191 {
192 struct sock *sk = sock->sk;
193 struct alg_sock *ask = alg_sk(sk);
194 struct hash_ctx *ctx = ask->private;
195 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
196 bool result;
197 int err;
198
199 if (len > ds)
200 len = ds;
201 else if (len < ds)
202 msg->msg_flags |= MSG_TRUNC;
203
204 lock_sock(sk);
205 result = ctx->result;
206 err = hash_alloc_result(sk, ctx);
207 if (err)
208 goto unlock;
209
210 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
211
212 if (!result && !ctx->more) {
213 err = af_alg_wait_for_completion(
214 crypto_ahash_init(&ctx->req),
215 &ctx->completion);
216 if (err)
217 goto unlock;
218 }
219
220 if (!result || ctx->more) {
221 ctx->more = 0;
222 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
223 &ctx->completion);
224 if (err)
225 goto unlock;
226 }
227
228 err = memcpy_to_msg(msg, ctx->result, len);
229
230 unlock:
231 hash_free_result(sk, ctx);
232 release_sock(sk);
233
234 return err ?: len;
235 }
236
hash_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)237 static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
238 bool kern)
239 {
240 struct sock *sk = sock->sk;
241 struct alg_sock *ask = alg_sk(sk);
242 struct hash_ctx *ctx = ask->private;
243 struct ahash_request *req = &ctx->req;
244 char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req)) ? : 1];
245 struct sock *sk2;
246 struct alg_sock *ask2;
247 struct hash_ctx *ctx2;
248 bool more;
249 int err;
250
251 lock_sock(sk);
252 more = ctx->more;
253 err = more ? crypto_ahash_export(req, state) : 0;
254 release_sock(sk);
255
256 if (err)
257 return err;
258
259 err = af_alg_accept(ask->parent, newsock, kern);
260 if (err)
261 return err;
262
263 sk2 = newsock->sk;
264 ask2 = alg_sk(sk2);
265 ctx2 = ask2->private;
266 ctx2->more = more;
267
268 if (!more)
269 return err;
270
271 err = crypto_ahash_import(&ctx2->req, state);
272 if (err) {
273 sock_orphan(sk2);
274 sock_put(sk2);
275 }
276
277 return err;
278 }
279
280 static struct proto_ops algif_hash_ops = {
281 .family = PF_ALG,
282
283 .connect = sock_no_connect,
284 .socketpair = sock_no_socketpair,
285 .getname = sock_no_getname,
286 .ioctl = sock_no_ioctl,
287 .listen = sock_no_listen,
288 .shutdown = sock_no_shutdown,
289 .getsockopt = sock_no_getsockopt,
290 .mmap = sock_no_mmap,
291 .bind = sock_no_bind,
292 .setsockopt = sock_no_setsockopt,
293 .poll = sock_no_poll,
294
295 .release = af_alg_release,
296 .sendmsg = hash_sendmsg,
297 .sendpage = hash_sendpage,
298 .recvmsg = hash_recvmsg,
299 .accept = hash_accept,
300 };
301
hash_check_key(struct socket * sock)302 static int hash_check_key(struct socket *sock)
303 {
304 int err = 0;
305 struct sock *psk;
306 struct alg_sock *pask;
307 struct crypto_ahash *tfm;
308 struct sock *sk = sock->sk;
309 struct alg_sock *ask = alg_sk(sk);
310
311 lock_sock(sk);
312 if (ask->refcnt)
313 goto unlock_child;
314
315 psk = ask->parent;
316 pask = alg_sk(ask->parent);
317 tfm = pask->private;
318
319 err = -ENOKEY;
320 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
321 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
322 goto unlock;
323
324 if (!pask->refcnt++)
325 sock_hold(psk);
326
327 ask->refcnt = 1;
328 sock_put(psk);
329
330 err = 0;
331
332 unlock:
333 release_sock(psk);
334 unlock_child:
335 release_sock(sk);
336
337 return err;
338 }
339
hash_sendmsg_nokey(struct socket * sock,struct msghdr * msg,size_t size)340 static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
341 size_t size)
342 {
343 int err;
344
345 err = hash_check_key(sock);
346 if (err)
347 return err;
348
349 return hash_sendmsg(sock, msg, size);
350 }
351
hash_sendpage_nokey(struct socket * sock,struct page * page,int offset,size_t size,int flags)352 static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
353 int offset, size_t size, int flags)
354 {
355 int err;
356
357 err = hash_check_key(sock);
358 if (err)
359 return err;
360
361 return hash_sendpage(sock, page, offset, size, flags);
362 }
363
hash_recvmsg_nokey(struct socket * sock,struct msghdr * msg,size_t ignored,int flags)364 static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
365 size_t ignored, int flags)
366 {
367 int err;
368
369 err = hash_check_key(sock);
370 if (err)
371 return err;
372
373 return hash_recvmsg(sock, msg, ignored, flags);
374 }
375
hash_accept_nokey(struct socket * sock,struct socket * newsock,int flags,bool kern)376 static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
377 int flags, bool kern)
378 {
379 int err;
380
381 err = hash_check_key(sock);
382 if (err)
383 return err;
384
385 return hash_accept(sock, newsock, flags, kern);
386 }
387
388 static struct proto_ops algif_hash_ops_nokey = {
389 .family = PF_ALG,
390
391 .connect = sock_no_connect,
392 .socketpair = sock_no_socketpair,
393 .getname = sock_no_getname,
394 .ioctl = sock_no_ioctl,
395 .listen = sock_no_listen,
396 .shutdown = sock_no_shutdown,
397 .getsockopt = sock_no_getsockopt,
398 .mmap = sock_no_mmap,
399 .bind = sock_no_bind,
400 .setsockopt = sock_no_setsockopt,
401 .poll = sock_no_poll,
402
403 .release = af_alg_release,
404 .sendmsg = hash_sendmsg_nokey,
405 .sendpage = hash_sendpage_nokey,
406 .recvmsg = hash_recvmsg_nokey,
407 .accept = hash_accept_nokey,
408 };
409
hash_bind(const char * name,u32 type,u32 mask)410 static void *hash_bind(const char *name, u32 type, u32 mask)
411 {
412 return crypto_alloc_ahash(name, type, mask);
413 }
414
hash_release(void * private)415 static void hash_release(void *private)
416 {
417 crypto_free_ahash(private);
418 }
419
hash_setkey(void * private,const u8 * key,unsigned int keylen)420 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
421 {
422 return crypto_ahash_setkey(private, key, keylen);
423 }
424
hash_sock_destruct(struct sock * sk)425 static void hash_sock_destruct(struct sock *sk)
426 {
427 struct alg_sock *ask = alg_sk(sk);
428 struct hash_ctx *ctx = ask->private;
429
430 hash_free_result(sk, ctx);
431 sock_kfree_s(sk, ctx, ctx->len);
432 af_alg_release_parent(sk);
433 }
434
hash_accept_parent_nokey(void * private,struct sock * sk)435 static int hash_accept_parent_nokey(void *private, struct sock *sk)
436 {
437 struct crypto_ahash *tfm = private;
438 struct alg_sock *ask = alg_sk(sk);
439 struct hash_ctx *ctx;
440 unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
441
442 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
443 if (!ctx)
444 return -ENOMEM;
445
446 ctx->result = NULL;
447 ctx->len = len;
448 ctx->more = 0;
449 af_alg_init_completion(&ctx->completion);
450
451 ask->private = ctx;
452
453 ahash_request_set_tfm(&ctx->req, tfm);
454 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
455 af_alg_complete, &ctx->completion);
456
457 sk->sk_destruct = hash_sock_destruct;
458
459 return 0;
460 }
461
hash_accept_parent(void * private,struct sock * sk)462 static int hash_accept_parent(void *private, struct sock *sk)
463 {
464 struct crypto_ahash *tfm = private;
465
466 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
467 return -ENOKEY;
468
469 return hash_accept_parent_nokey(private, sk);
470 }
471
472 static const struct af_alg_type algif_type_hash = {
473 .bind = hash_bind,
474 .release = hash_release,
475 .setkey = hash_setkey,
476 .accept = hash_accept_parent,
477 .accept_nokey = hash_accept_parent_nokey,
478 .ops = &algif_hash_ops,
479 .ops_nokey = &algif_hash_ops_nokey,
480 .name = "hash",
481 .owner = THIS_MODULE
482 };
483
algif_hash_init(void)484 static int __init algif_hash_init(void)
485 {
486 return af_alg_register_type(&algif_type_hash);
487 }
488
algif_hash_exit(void)489 static void __exit algif_hash_exit(void)
490 {
491 int err = af_alg_unregister_type(&algif_type_hash);
492 BUG_ON(err);
493 }
494
495 module_init(algif_hash_init);
496 module_exit(algif_hash_exit);
497 MODULE_LICENSE("GPL");
498