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