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)) ? : 1];
188 struct sock *sk2;
189 struct alg_sock *ask2;
190 struct hash_ctx *ctx2;
191 bool more;
192 int err;
193
194 lock_sock(sk);
195 more = ctx->more;
196 err = more ? crypto_ahash_export(req, state) : 0;
197 release_sock(sk);
198
199 if (err)
200 return err;
201
202 err = af_alg_accept(ask->parent, newsock);
203 if (err)
204 return err;
205
206 sk2 = newsock->sk;
207 ask2 = alg_sk(sk2);
208 ctx2 = ask2->private;
209 ctx2->more = more;
210
211 if (!more)
212 return err;
213
214 err = crypto_ahash_import(&ctx2->req, state);
215 if (err) {
216 sock_orphan(sk2);
217 sock_put(sk2);
218 }
219
220 return err;
221 }
222
223 static struct proto_ops algif_hash_ops = {
224 .family = PF_ALG,
225
226 .connect = sock_no_connect,
227 .socketpair = sock_no_socketpair,
228 .getname = sock_no_getname,
229 .ioctl = sock_no_ioctl,
230 .listen = sock_no_listen,
231 .shutdown = sock_no_shutdown,
232 .getsockopt = sock_no_getsockopt,
233 .mmap = sock_no_mmap,
234 .bind = sock_no_bind,
235 .setsockopt = sock_no_setsockopt,
236 .poll = sock_no_poll,
237
238 .release = af_alg_release,
239 .sendmsg = hash_sendmsg,
240 .sendpage = hash_sendpage,
241 .recvmsg = hash_recvmsg,
242 .accept = hash_accept,
243 };
244
hash_check_key(struct socket * sock)245 static int hash_check_key(struct socket *sock)
246 {
247 int err = 0;
248 struct sock *psk;
249 struct alg_sock *pask;
250 struct algif_hash_tfm *tfm;
251 struct sock *sk = sock->sk;
252 struct alg_sock *ask = alg_sk(sk);
253
254 lock_sock(sk);
255 if (!atomic_read(&ask->nokey_refcnt))
256 goto unlock_child;
257
258 psk = ask->parent;
259 pask = alg_sk(ask->parent);
260 tfm = pask->private;
261
262 err = -ENOKEY;
263 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
264 if (!tfm->has_key)
265 goto unlock;
266
267 atomic_dec(&pask->nokey_refcnt);
268 atomic_set(&ask->nokey_refcnt, 0);
269
270 err = 0;
271
272 unlock:
273 release_sock(psk);
274 unlock_child:
275 release_sock(sk);
276
277 return err;
278 }
279
hash_sendmsg_nokey(struct socket * sock,struct msghdr * msg,size_t size)280 static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
281 size_t size)
282 {
283 int err;
284
285 err = hash_check_key(sock);
286 if (err)
287 return err;
288
289 return hash_sendmsg(sock, msg, size);
290 }
291
hash_sendpage_nokey(struct socket * sock,struct page * page,int offset,size_t size,int flags)292 static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
293 int offset, size_t size, int flags)
294 {
295 int err;
296
297 err = hash_check_key(sock);
298 if (err)
299 return err;
300
301 return hash_sendpage(sock, page, offset, size, flags);
302 }
303
hash_recvmsg_nokey(struct socket * sock,struct msghdr * msg,size_t ignored,int flags)304 static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
305 size_t ignored, int flags)
306 {
307 int err;
308
309 err = hash_check_key(sock);
310 if (err)
311 return err;
312
313 return hash_recvmsg(sock, msg, ignored, flags);
314 }
315
hash_accept_nokey(struct socket * sock,struct socket * newsock,int flags)316 static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
317 int flags)
318 {
319 int err;
320
321 err = hash_check_key(sock);
322 if (err)
323 return err;
324
325 return hash_accept(sock, newsock, flags);
326 }
327
328 static struct proto_ops algif_hash_ops_nokey = {
329 .family = PF_ALG,
330
331 .connect = sock_no_connect,
332 .socketpair = sock_no_socketpair,
333 .getname = sock_no_getname,
334 .ioctl = sock_no_ioctl,
335 .listen = sock_no_listen,
336 .shutdown = sock_no_shutdown,
337 .getsockopt = sock_no_getsockopt,
338 .mmap = sock_no_mmap,
339 .bind = sock_no_bind,
340 .setsockopt = sock_no_setsockopt,
341 .poll = sock_no_poll,
342
343 .release = af_alg_release,
344 .sendmsg = hash_sendmsg_nokey,
345 .sendpage = hash_sendpage_nokey,
346 .recvmsg = hash_recvmsg_nokey,
347 .accept = hash_accept_nokey,
348 };
349
hash_bind(const char * name,u32 type,u32 mask)350 static void *hash_bind(const char *name, u32 type, u32 mask)
351 {
352 struct algif_hash_tfm *tfm;
353 struct crypto_ahash *hash;
354
355 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
356 if (!tfm)
357 return ERR_PTR(-ENOMEM);
358
359 hash = crypto_alloc_ahash(name, type, mask);
360 if (IS_ERR(hash)) {
361 kfree(tfm);
362 return ERR_CAST(hash);
363 }
364
365 tfm->hash = hash;
366
367 return tfm;
368 }
369
hash_release(void * private)370 static void hash_release(void *private)
371 {
372 struct algif_hash_tfm *tfm = private;
373
374 crypto_free_ahash(tfm->hash);
375 kfree(tfm);
376 }
377
hash_setkey(void * private,const u8 * key,unsigned int keylen)378 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
379 {
380 struct algif_hash_tfm *tfm = private;
381 int err;
382
383 err = crypto_ahash_setkey(tfm->hash, key, keylen);
384 tfm->has_key = !err;
385
386 return err;
387 }
388
hash_sock_destruct(struct sock * sk)389 static void hash_sock_destruct(struct sock *sk)
390 {
391 struct alg_sock *ask = alg_sk(sk);
392 struct hash_ctx *ctx = ask->private;
393
394 sock_kzfree_s(sk, ctx->result,
395 crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
396 sock_kfree_s(sk, ctx, ctx->len);
397 af_alg_release_parent(sk);
398 }
399
hash_accept_parent_nokey(void * private,struct sock * sk)400 static int hash_accept_parent_nokey(void *private, struct sock *sk)
401 {
402 struct hash_ctx *ctx;
403 struct alg_sock *ask = alg_sk(sk);
404 struct algif_hash_tfm *tfm = private;
405 struct crypto_ahash *hash = tfm->hash;
406 unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(hash);
407 unsigned ds = crypto_ahash_digestsize(hash);
408
409 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
410 if (!ctx)
411 return -ENOMEM;
412
413 ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
414 if (!ctx->result) {
415 sock_kfree_s(sk, ctx, len);
416 return -ENOMEM;
417 }
418
419 memset(ctx->result, 0, ds);
420
421 ctx->len = len;
422 ctx->more = 0;
423 af_alg_init_completion(&ctx->completion);
424
425 ask->private = ctx;
426
427 ahash_request_set_tfm(&ctx->req, hash);
428 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
429 af_alg_complete, &ctx->completion);
430
431 sk->sk_destruct = hash_sock_destruct;
432
433 return 0;
434 }
435
hash_accept_parent(void * private,struct sock * sk)436 static int hash_accept_parent(void *private, struct sock *sk)
437 {
438 struct algif_hash_tfm *tfm = private;
439
440 if (!tfm->has_key && crypto_ahash_has_setkey(tfm->hash))
441 return -ENOKEY;
442
443 return hash_accept_parent_nokey(private, sk);
444 }
445
446 static const struct af_alg_type algif_type_hash = {
447 .bind = hash_bind,
448 .release = hash_release,
449 .setkey = hash_setkey,
450 .accept = hash_accept_parent,
451 .accept_nokey = hash_accept_parent_nokey,
452 .ops = &algif_hash_ops,
453 .ops_nokey = &algif_hash_ops_nokey,
454 .name = "hash",
455 .owner = THIS_MODULE
456 };
457
algif_hash_init(void)458 static int __init algif_hash_init(void)
459 {
460 return af_alg_register_type(&algif_type_hash);
461 }
462
algif_hash_exit(void)463 static void __exit algif_hash_exit(void)
464 {
465 int err = af_alg_unregister_type(&algif_type_hash);
466 BUG_ON(err);
467 }
468
469 module_init(algif_hash_init);
470 module_exit(algif_hash_exit);
471 MODULE_LICENSE("GPL");
472