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 kiocb * unused,struct socket * sock,struct msghdr * msg,size_t ignored)42 static int hash_sendmsg(struct kiocb *unused, struct socket *sock,
43 struct msghdr *msg, 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 unsigned long iovlen;
50 struct iovec *iov;
51 long copied = 0;
52 int err;
53
54 if (limit > sk->sk_sndbuf)
55 limit = sk->sk_sndbuf;
56
57 lock_sock(sk);
58 if (!ctx->more) {
59 err = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
60 &ctx->completion);
61 if (err)
62 goto unlock;
63 }
64
65 ctx->more = 0;
66
67 for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0;
68 iovlen--, iov++) {
69 unsigned long seglen = iov->iov_len;
70 char __user *from = iov->iov_base;
71
72 while (seglen) {
73 int len = min_t(unsigned long, seglen, limit);
74 int newlen;
75
76 newlen = af_alg_make_sg(&ctx->sgl, from, len, 0);
77 if (newlen < 0) {
78 err = copied ? 0 : newlen;
79 goto unlock;
80 }
81
82 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL,
83 newlen);
84
85 err = af_alg_wait_for_completion(
86 crypto_ahash_update(&ctx->req),
87 &ctx->completion);
88
89 af_alg_free_sg(&ctx->sgl);
90
91 if (err)
92 goto unlock;
93
94 seglen -= newlen;
95 from += newlen;
96 copied += newlen;
97 }
98 }
99
100 err = 0;
101
102 ctx->more = msg->msg_flags & MSG_MORE;
103 if (!ctx->more) {
104 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
105 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
106 &ctx->completion);
107 }
108
109 unlock:
110 release_sock(sk);
111
112 return err ?: copied;
113 }
114
hash_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)115 static ssize_t hash_sendpage(struct socket *sock, struct page *page,
116 int offset, size_t size, int flags)
117 {
118 struct sock *sk = sock->sk;
119 struct alg_sock *ask = alg_sk(sk);
120 struct hash_ctx *ctx = ask->private;
121 int err;
122
123 if (flags & MSG_SENDPAGE_NOTLAST)
124 flags |= MSG_MORE;
125
126 lock_sock(sk);
127 sg_init_table(ctx->sgl.sg, 1);
128 sg_set_page(ctx->sgl.sg, page, size, offset);
129
130 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
131
132 if (!(flags & MSG_MORE)) {
133 if (ctx->more)
134 err = crypto_ahash_finup(&ctx->req);
135 else
136 err = crypto_ahash_digest(&ctx->req);
137 } else {
138 if (!ctx->more) {
139 err = crypto_ahash_init(&ctx->req);
140 err = af_alg_wait_for_completion(err, &ctx->completion);
141 if (err)
142 goto unlock;
143 }
144
145 err = crypto_ahash_update(&ctx->req);
146 }
147
148 err = af_alg_wait_for_completion(err, &ctx->completion);
149 if (err)
150 goto unlock;
151
152 ctx->more = flags & MSG_MORE;
153
154 unlock:
155 release_sock(sk);
156
157 return err ?: size;
158 }
159
hash_recvmsg(struct kiocb * unused,struct socket * sock,struct msghdr * msg,size_t len,int flags)160 static int hash_recvmsg(struct kiocb *unused, struct socket *sock,
161 struct msghdr *msg, size_t len, int flags)
162 {
163 struct sock *sk = sock->sk;
164 struct alg_sock *ask = alg_sk(sk);
165 struct hash_ctx *ctx = ask->private;
166 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
167 int err;
168
169 if (len > ds)
170 len = ds;
171 else if (len < ds)
172 msg->msg_flags |= MSG_TRUNC;
173
174 lock_sock(sk);
175 if (ctx->more) {
176 ctx->more = 0;
177 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
178 err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
179 &ctx->completion);
180 if (err)
181 goto unlock;
182 }
183
184 err = memcpy_toiovec(msg->msg_iov, ctx->result, len);
185
186 unlock:
187 release_sock(sk);
188
189 return err ?: len;
190 }
191
hash_accept(struct socket * sock,struct socket * newsock,int flags)192 static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
193 {
194 struct sock *sk = sock->sk;
195 struct alg_sock *ask = alg_sk(sk);
196 struct hash_ctx *ctx = ask->private;
197 struct ahash_request *req = &ctx->req;
198 char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req)) ? : 1];
199 struct sock *sk2;
200 struct alg_sock *ask2;
201 struct hash_ctx *ctx2;
202 int err;
203
204 err = crypto_ahash_export(req, state);
205 if (err)
206 return err;
207
208 err = af_alg_accept(ask->parent, newsock);
209 if (err)
210 return err;
211
212 sk2 = newsock->sk;
213 ask2 = alg_sk(sk2);
214 ctx2 = ask2->private;
215 ctx2->more = 1;
216
217 err = crypto_ahash_import(&ctx2->req, state);
218 if (err) {
219 sock_orphan(sk2);
220 sock_put(sk2);
221 }
222
223 return err;
224 }
225
226 static struct proto_ops algif_hash_ops = {
227 .family = PF_ALG,
228
229 .connect = sock_no_connect,
230 .socketpair = sock_no_socketpair,
231 .getname = sock_no_getname,
232 .ioctl = sock_no_ioctl,
233 .listen = sock_no_listen,
234 .shutdown = sock_no_shutdown,
235 .getsockopt = sock_no_getsockopt,
236 .mmap = sock_no_mmap,
237 .bind = sock_no_bind,
238 .setsockopt = sock_no_setsockopt,
239 .poll = sock_no_poll,
240
241 .release = af_alg_release,
242 .sendmsg = hash_sendmsg,
243 .sendpage = hash_sendpage,
244 .recvmsg = hash_recvmsg,
245 .accept = hash_accept,
246 };
247
hash_check_key(struct socket * sock)248 static int hash_check_key(struct socket *sock)
249 {
250 int err = 0;
251 struct sock *psk;
252 struct alg_sock *pask;
253 struct algif_hash_tfm *tfm;
254 struct sock *sk = sock->sk;
255 struct alg_sock *ask = alg_sk(sk);
256
257 lock_sock(sk);
258 if (ask->refcnt)
259 goto unlock_child;
260
261 psk = ask->parent;
262 pask = alg_sk(ask->parent);
263 tfm = pask->private;
264
265 err = -ENOKEY;
266 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
267 if (!tfm->has_key)
268 goto unlock;
269
270 if (!pask->refcnt++)
271 sock_hold(psk);
272
273 ask->refcnt = 1;
274 sock_put(psk);
275
276 err = 0;
277
278 unlock:
279 release_sock(psk);
280 unlock_child:
281 release_sock(sk);
282
283 return err;
284 }
285
hash_sendmsg_nokey(struct kiocb * unused,struct socket * sock,struct msghdr * msg,size_t size)286 static int hash_sendmsg_nokey(struct kiocb *unused, struct socket *sock,
287 struct msghdr *msg, size_t size)
288 {
289 int err;
290
291 err = hash_check_key(sock);
292 if (err)
293 return err;
294
295 return hash_sendmsg(NULL, sock, msg, size);
296 }
297
hash_sendpage_nokey(struct socket * sock,struct page * page,int offset,size_t size,int flags)298 static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
299 int offset, size_t size, int flags)
300 {
301 int err;
302
303 err = hash_check_key(sock);
304 if (err)
305 return err;
306
307 return hash_sendpage(sock, page, offset, size, flags);
308 }
309
hash_recvmsg_nokey(struct kiocb * unused,struct socket * sock,struct msghdr * msg,size_t ignored,int flags)310 static int hash_recvmsg_nokey(struct kiocb *unused, struct socket *sock,
311 struct msghdr *msg, size_t ignored, int flags)
312 {
313 int err;
314
315 err = hash_check_key(sock);
316 if (err)
317 return err;
318
319 return hash_recvmsg(NULL, sock, msg, ignored, flags);
320 }
321
hash_accept_nokey(struct socket * sock,struct socket * newsock,int flags)322 static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
323 int flags)
324 {
325 int err;
326
327 err = hash_check_key(sock);
328 if (err)
329 return err;
330
331 return hash_accept(sock, newsock, flags);
332 }
333
334 static struct proto_ops algif_hash_ops_nokey = {
335 .family = PF_ALG,
336
337 .connect = sock_no_connect,
338 .socketpair = sock_no_socketpair,
339 .getname = sock_no_getname,
340 .ioctl = sock_no_ioctl,
341 .listen = sock_no_listen,
342 .shutdown = sock_no_shutdown,
343 .getsockopt = sock_no_getsockopt,
344 .mmap = sock_no_mmap,
345 .bind = sock_no_bind,
346 .setsockopt = sock_no_setsockopt,
347 .poll = sock_no_poll,
348
349 .release = af_alg_release,
350 .sendmsg = hash_sendmsg_nokey,
351 .sendpage = hash_sendpage_nokey,
352 .recvmsg = hash_recvmsg_nokey,
353 .accept = hash_accept_nokey,
354 };
355
hash_bind(const char * name,u32 type,u32 mask)356 static void *hash_bind(const char *name, u32 type, u32 mask)
357 {
358 struct algif_hash_tfm *tfm;
359 struct crypto_ahash *hash;
360
361 tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
362 if (!tfm)
363 return ERR_PTR(-ENOMEM);
364
365 hash = crypto_alloc_ahash(name, type, mask);
366 if (IS_ERR(hash)) {
367 kfree(tfm);
368 return ERR_CAST(hash);
369 }
370
371 tfm->hash = hash;
372
373 return tfm;
374 }
375
hash_release(void * private)376 static void hash_release(void *private)
377 {
378 struct algif_hash_tfm *tfm = private;
379
380 crypto_free_ahash(tfm->hash);
381 kfree(tfm);
382 }
383
hash_setkey(void * private,const u8 * key,unsigned int keylen)384 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
385 {
386 struct algif_hash_tfm *tfm = private;
387 int err;
388
389 err = crypto_ahash_setkey(tfm->hash, key, keylen);
390 tfm->has_key = !err;
391
392 return err;
393 }
394
hash_sock_destruct(struct sock * sk)395 static void hash_sock_destruct(struct sock *sk)
396 {
397 struct alg_sock *ask = alg_sk(sk);
398 struct hash_ctx *ctx = ask->private;
399
400 sock_kfree_s(sk, ctx->result,
401 crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
402 sock_kfree_s(sk, ctx, ctx->len);
403 af_alg_release_parent(sk);
404 }
405
hash_accept_parent_nokey(void * private,struct sock * sk)406 static int hash_accept_parent_nokey(void *private, struct sock *sk)
407 {
408 struct hash_ctx *ctx;
409 struct alg_sock *ask = alg_sk(sk);
410 struct algif_hash_tfm *tfm = private;
411 struct crypto_ahash *hash = tfm->hash;
412 unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(hash);
413 unsigned ds = crypto_ahash_digestsize(hash);
414
415 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
416 if (!ctx)
417 return -ENOMEM;
418
419 ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
420 if (!ctx->result) {
421 sock_kfree_s(sk, ctx, len);
422 return -ENOMEM;
423 }
424
425 memset(ctx->result, 0, ds);
426
427 ctx->len = len;
428 ctx->more = 0;
429 af_alg_init_completion(&ctx->completion);
430
431 ask->private = ctx;
432
433 ahash_request_set_tfm(&ctx->req, hash);
434 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
435 af_alg_complete, &ctx->completion);
436
437 sk->sk_destruct = hash_sock_destruct;
438
439 return 0;
440 }
441
hash_accept_parent(void * private,struct sock * sk)442 static int hash_accept_parent(void *private, struct sock *sk)
443 {
444 struct algif_hash_tfm *tfm = private;
445
446 if (!tfm->has_key && crypto_ahash_has_setkey(tfm->hash))
447 return -ENOKEY;
448
449 return hash_accept_parent_nokey(private, sk);
450 }
451
452 static const struct af_alg_type algif_type_hash = {
453 .bind = hash_bind,
454 .release = hash_release,
455 .setkey = hash_setkey,
456 .accept = hash_accept_parent,
457 .accept_nokey = hash_accept_parent_nokey,
458 .ops = &algif_hash_ops,
459 .ops_nokey = &algif_hash_ops_nokey,
460 .name = "hash",
461 .owner = THIS_MODULE
462 };
463
algif_hash_init(void)464 static int __init algif_hash_init(void)
465 {
466 return af_alg_register_type(&algif_type_hash);
467 }
468
algif_hash_exit(void)469 static void __exit algif_hash_exit(void)
470 {
471 int err = af_alg_unregister_type(&algif_type_hash);
472 BUG_ON(err);
473 }
474
475 module_init(algif_hash_init);
476 module_exit(algif_hash_exit);
477 MODULE_LICENSE("GPL");
478