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)237 static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
238 {
239 struct sock *sk = sock->sk;
240 struct alg_sock *ask = alg_sk(sk);
241 struct hash_ctx *ctx = ask->private;
242 struct ahash_request *req = &ctx->req;
243 char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req)) ? : 1];
244 struct sock *sk2;
245 struct alg_sock *ask2;
246 struct hash_ctx *ctx2;
247 bool more;
248 int err;
249
250 lock_sock(sk);
251 more = ctx->more;
252 err = more ? crypto_ahash_export(req, state) : 0;
253 release_sock(sk);
254
255 if (err)
256 return err;
257
258 err = af_alg_accept(ask->parent, newsock);
259 if (err)
260 return err;
261
262 sk2 = newsock->sk;
263 ask2 = alg_sk(sk2);
264 ctx2 = ask2->private;
265 ctx2->more = more;
266
267 if (!more)
268 return err;
269
270 err = crypto_ahash_import(&ctx2->req, state);
271 if (err) {
272 sock_orphan(sk2);
273 sock_put(sk2);
274 }
275
276 return err;
277 }
278
279 static struct proto_ops algif_hash_ops = {
280 .family = PF_ALG,
281
282 .connect = sock_no_connect,
283 .socketpair = sock_no_socketpair,
284 .getname = sock_no_getname,
285 .ioctl = sock_no_ioctl,
286 .listen = sock_no_listen,
287 .shutdown = sock_no_shutdown,
288 .getsockopt = sock_no_getsockopt,
289 .mmap = sock_no_mmap,
290 .bind = sock_no_bind,
291 .setsockopt = sock_no_setsockopt,
292 .poll = sock_no_poll,
293
294 .release = af_alg_release,
295 .sendmsg = hash_sendmsg,
296 .sendpage = hash_sendpage,
297 .recvmsg = hash_recvmsg,
298 .accept = hash_accept,
299 };
300
hash_check_key(struct socket * sock)301 static int hash_check_key(struct socket *sock)
302 {
303 int err = 0;
304 struct sock *psk;
305 struct alg_sock *pask;
306 struct crypto_ahash *tfm;
307 struct sock *sk = sock->sk;
308 struct alg_sock *ask = alg_sk(sk);
309
310 lock_sock(sk);
311 if (ask->refcnt)
312 goto unlock_child;
313
314 psk = ask->parent;
315 pask = alg_sk(ask->parent);
316 tfm = pask->private;
317
318 err = -ENOKEY;
319 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
320 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
321 goto unlock;
322
323 if (!pask->refcnt++)
324 sock_hold(psk);
325
326 ask->refcnt = 1;
327 sock_put(psk);
328
329 err = 0;
330
331 unlock:
332 release_sock(psk);
333 unlock_child:
334 release_sock(sk);
335
336 return err;
337 }
338
hash_sendmsg_nokey(struct socket * sock,struct msghdr * msg,size_t size)339 static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
340 size_t size)
341 {
342 int err;
343
344 err = hash_check_key(sock);
345 if (err)
346 return err;
347
348 return hash_sendmsg(sock, msg, size);
349 }
350
hash_sendpage_nokey(struct socket * sock,struct page * page,int offset,size_t size,int flags)351 static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
352 int offset, size_t size, int flags)
353 {
354 int err;
355
356 err = hash_check_key(sock);
357 if (err)
358 return err;
359
360 return hash_sendpage(sock, page, offset, size, flags);
361 }
362
hash_recvmsg_nokey(struct socket * sock,struct msghdr * msg,size_t ignored,int flags)363 static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
364 size_t ignored, int flags)
365 {
366 int err;
367
368 err = hash_check_key(sock);
369 if (err)
370 return err;
371
372 return hash_recvmsg(sock, msg, ignored, flags);
373 }
374
hash_accept_nokey(struct socket * sock,struct socket * newsock,int flags)375 static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
376 int flags)
377 {
378 int err;
379
380 err = hash_check_key(sock);
381 if (err)
382 return err;
383
384 return hash_accept(sock, newsock, flags);
385 }
386
387 static struct proto_ops algif_hash_ops_nokey = {
388 .family = PF_ALG,
389
390 .connect = sock_no_connect,
391 .socketpair = sock_no_socketpair,
392 .getname = sock_no_getname,
393 .ioctl = sock_no_ioctl,
394 .listen = sock_no_listen,
395 .shutdown = sock_no_shutdown,
396 .getsockopt = sock_no_getsockopt,
397 .mmap = sock_no_mmap,
398 .bind = sock_no_bind,
399 .setsockopt = sock_no_setsockopt,
400 .poll = sock_no_poll,
401
402 .release = af_alg_release,
403 .sendmsg = hash_sendmsg_nokey,
404 .sendpage = hash_sendpage_nokey,
405 .recvmsg = hash_recvmsg_nokey,
406 .accept = hash_accept_nokey,
407 };
408
hash_bind(const char * name,u32 type,u32 mask)409 static void *hash_bind(const char *name, u32 type, u32 mask)
410 {
411 return crypto_alloc_ahash(name, type, mask);
412 }
413
hash_release(void * private)414 static void hash_release(void *private)
415 {
416 crypto_free_ahash(private);
417 }
418
hash_setkey(void * private,const u8 * key,unsigned int keylen)419 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
420 {
421 return crypto_ahash_setkey(private, key, keylen);
422 }
423
hash_sock_destruct(struct sock * sk)424 static void hash_sock_destruct(struct sock *sk)
425 {
426 struct alg_sock *ask = alg_sk(sk);
427 struct hash_ctx *ctx = ask->private;
428
429 hash_free_result(sk, ctx);
430 sock_kfree_s(sk, ctx, ctx->len);
431 af_alg_release_parent(sk);
432 }
433
hash_accept_parent_nokey(void * private,struct sock * sk)434 static int hash_accept_parent_nokey(void *private, struct sock *sk)
435 {
436 struct crypto_ahash *tfm = private;
437 struct alg_sock *ask = alg_sk(sk);
438 struct hash_ctx *ctx;
439 unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
440
441 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
442 if (!ctx)
443 return -ENOMEM;
444
445 ctx->result = NULL;
446 ctx->len = len;
447 ctx->more = 0;
448 af_alg_init_completion(&ctx->completion);
449
450 ask->private = ctx;
451
452 ahash_request_set_tfm(&ctx->req, tfm);
453 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
454 af_alg_complete, &ctx->completion);
455
456 sk->sk_destruct = hash_sock_destruct;
457
458 return 0;
459 }
460
hash_accept_parent(void * private,struct sock * sk)461 static int hash_accept_parent(void *private, struct sock *sk)
462 {
463 struct crypto_ahash *tfm = private;
464
465 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
466 return -ENOKEY;
467
468 return hash_accept_parent_nokey(private, sk);
469 }
470
471 static const struct af_alg_type algif_type_hash = {
472 .bind = hash_bind,
473 .release = hash_release,
474 .setkey = hash_setkey,
475 .accept = hash_accept_parent,
476 .accept_nokey = hash_accept_parent_nokey,
477 .ops = &algif_hash_ops,
478 .ops_nokey = &algif_hash_ops_nokey,
479 .name = "hash",
480 .owner = THIS_MODULE
481 };
482
algif_hash_init(void)483 static int __init algif_hash_init(void)
484 {
485 return af_alg_register_type(&algif_type_hash);
486 }
487
algif_hash_exit(void)488 static void __exit algif_hash_exit(void)
489 {
490 int err = af_alg_unregister_type(&algif_type_hash);
491 BUG_ON(err);
492 }
493
494 module_init(algif_hash_init);
495 module_exit(algif_hash_exit);
496 MODULE_LICENSE("GPL");
497