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
24struct hash_ctx {
25 struct af_alg_sgl sgl;
26
27 u8 *result;
28
29 struct crypto_wait wait;
30
31 unsigned int len;
32 bool more;
33
34 struct ahash_request req;
35};
36
37static 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
55static 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
68static 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 = crypto_wait_req(crypto_ahash_init(&ctx->req), &ctx->wait);
87 if (err)
88 goto unlock;
89 }
90
91 ctx->more = 0;
92
93 while (msg_data_left(msg)) {
94 int len = msg_data_left(msg);
95
96 if (len > limit)
97 len = limit;
98
99 len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
100 if (len < 0) {
101 err = copied ? 0 : len;
102 goto unlock;
103 }
104
105 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
106
107 err = crypto_wait_req(crypto_ahash_update(&ctx->req),
108 &ctx->wait);
109 af_alg_free_sg(&ctx->sgl);
110 if (err)
111 goto unlock;
112
113 copied += len;
114 iov_iter_advance(&msg->msg_iter, len);
115 }
116
117 err = 0;
118
119 ctx->more = msg->msg_flags & MSG_MORE;
120 if (!ctx->more) {
121 err = hash_alloc_result(sk, ctx);
122 if (err)
123 goto unlock;
124
125 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
126 err = crypto_wait_req(crypto_ahash_final(&ctx->req),
127 &ctx->wait);
128 }
129
130unlock:
131 release_sock(sk);
132
133 return err ?: copied;
134}
135
136static ssize_t hash_sendpage(struct socket *sock, struct page *page,
137 int offset, size_t size, int flags)
138{
139 struct sock *sk = sock->sk;
140 struct alg_sock *ask = alg_sk(sk);
141 struct hash_ctx *ctx = ask->private;
142 int err;
143
144 if (flags & MSG_SENDPAGE_NOTLAST)
145 flags |= MSG_MORE;
146
147 lock_sock(sk);
148 sg_init_table(ctx->sgl.sg, 1);
149 sg_set_page(ctx->sgl.sg, page, size, offset);
150
151 if (!(flags & MSG_MORE)) {
152 err = hash_alloc_result(sk, ctx);
153 if (err)
154 goto unlock;
155 } else if (!ctx->more)
156 hash_free_result(sk, ctx);
157
158 ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
159
160 if (!(flags & MSG_MORE)) {
161 if (ctx->more)
162 err = crypto_ahash_finup(&ctx->req);
163 else
164 err = crypto_ahash_digest(&ctx->req);
165 } else {
166 if (!ctx->more) {
167 err = crypto_ahash_init(&ctx->req);
168 err = crypto_wait_req(err, &ctx->wait);
169 if (err)
170 goto unlock;
171 }
172
173 err = crypto_ahash_update(&ctx->req);
174 }
175
176 err = crypto_wait_req(err, &ctx->wait);
177 if (err)
178 goto unlock;
179
180 ctx->more = flags & MSG_MORE;
181
182unlock:
183 release_sock(sk);
184
185 return err ?: size;
186}
187
188static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
189 int flags)
190{
191 struct sock *sk = sock->sk;
192 struct alg_sock *ask = alg_sk(sk);
193 struct hash_ctx *ctx = ask->private;
194 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
195 bool result;
196 int err;
197
198 if (len > ds)
199 len = ds;
200 else if (len < ds)
201 msg->msg_flags |= MSG_TRUNC;
202
203 lock_sock(sk);
204 result = ctx->result;
205 err = hash_alloc_result(sk, ctx);
206 if (err)
207 goto unlock;
208
209 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
210
211 if (!result && !ctx->more) {
212 err = crypto_wait_req(crypto_ahash_init(&ctx->req),
213 &ctx->wait);
214 if (err)
215 goto unlock;
216 }
217
218 if (!result || ctx->more) {
219 ctx->more = 0;
220 err = crypto_wait_req(crypto_ahash_final(&ctx->req),
221 &ctx->wait);
222 if (err)
223 goto unlock;
224 }
225
226 err = memcpy_to_msg(msg, ctx->result, len);
227
228unlock:
229 hash_free_result(sk, ctx);
230 release_sock(sk);
231
232 return err ?: len;
233}
234
235static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
236 bool kern)
237{
238 struct sock *sk = sock->sk;
239 struct alg_sock *ask = alg_sk(sk);
240 struct hash_ctx *ctx = ask->private;
241 struct ahash_request *req = &ctx->req;
242 char state[HASH_MAX_STATESIZE];
243 struct sock *sk2;
244 struct alg_sock *ask2;
245 struct hash_ctx *ctx2;
246 bool more;
247 int err;
248
249 lock_sock(sk);
250 more = ctx->more;
251 err = more ? crypto_ahash_export(req, state) : 0;
252 release_sock(sk);
253
254 if (err)
255 return err;
256
257 err = af_alg_accept(ask->parent, newsock, kern);
258 if (err)
259 return err;
260
261 sk2 = newsock->sk;
262 ask2 = alg_sk(sk2);
263 ctx2 = ask2->private;
264 ctx2->more = more;
265
266 if (!more)
267 return err;
268
269 err = crypto_ahash_import(&ctx2->req, state);
270 if (err) {
271 sock_orphan(sk2);
272 sock_put(sk2);
273 }
274
275 return err;
276}
277
278static struct proto_ops algif_hash_ops = {
279 .family = PF_ALG,
280
281 .connect = sock_no_connect,
282 .socketpair = sock_no_socketpair,
283 .getname = sock_no_getname,
284 .ioctl = sock_no_ioctl,
285 .listen = sock_no_listen,
286 .shutdown = sock_no_shutdown,
287 .getsockopt = sock_no_getsockopt,
288 .mmap = sock_no_mmap,
289 .bind = sock_no_bind,
290 .setsockopt = sock_no_setsockopt,
291
292 .release = af_alg_release,
293 .sendmsg = hash_sendmsg,
294 .sendpage = hash_sendpage,
295 .recvmsg = hash_recvmsg,
296 .accept = hash_accept,
297};
298
299static int hash_check_key(struct socket *sock)
300{
301 int err = 0;
302 struct sock *psk;
303 struct alg_sock *pask;
304 struct crypto_ahash *tfm;
305 struct sock *sk = sock->sk;
306 struct alg_sock *ask = alg_sk(sk);
307
308 lock_sock(sk);
309 if (ask->refcnt)
310 goto unlock_child;
311
312 psk = ask->parent;
313 pask = alg_sk(ask->parent);
314 tfm = pask->private;
315
316 err = -ENOKEY;
317 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
318 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
319 goto unlock;
320
321 if (!pask->refcnt++)
322 sock_hold(psk);
323
324 ask->refcnt = 1;
325 sock_put(psk);
326
327 err = 0;
328
329unlock:
330 release_sock(psk);
331unlock_child:
332 release_sock(sk);
333
334 return err;
335}
336
337static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
338 size_t size)
339{
340 int err;
341
342 err = hash_check_key(sock);
343 if (err)
344 return err;
345
346 return hash_sendmsg(sock, msg, size);
347}
348
349static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
350 int offset, size_t size, int flags)
351{
352 int err;
353
354 err = hash_check_key(sock);
355 if (err)
356 return err;
357
358 return hash_sendpage(sock, page, offset, size, flags);
359}
360
361static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
362 size_t ignored, int flags)
363{
364 int err;
365
366 err = hash_check_key(sock);
367 if (err)
368 return err;
369
370 return hash_recvmsg(sock, msg, ignored, flags);
371}
372
373static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
374 int flags, bool kern)
375{
376 int err;
377
378 err = hash_check_key(sock);
379 if (err)
380 return err;
381
382 return hash_accept(sock, newsock, flags, kern);
383}
384
385static struct proto_ops algif_hash_ops_nokey = {
386 .family = PF_ALG,
387
388 .connect = sock_no_connect,
389 .socketpair = sock_no_socketpair,
390 .getname = sock_no_getname,
391 .ioctl = sock_no_ioctl,
392 .listen = sock_no_listen,
393 .shutdown = sock_no_shutdown,
394 .getsockopt = sock_no_getsockopt,
395 .mmap = sock_no_mmap,
396 .bind = sock_no_bind,
397 .setsockopt = sock_no_setsockopt,
398
399 .release = af_alg_release,
400 .sendmsg = hash_sendmsg_nokey,
401 .sendpage = hash_sendpage_nokey,
402 .recvmsg = hash_recvmsg_nokey,
403 .accept = hash_accept_nokey,
404};
405
406static void *hash_bind(const char *name, u32 type, u32 mask)
407{
408 return crypto_alloc_ahash(name, type, mask);
409}
410
411static void hash_release(void *private)
412{
413 crypto_free_ahash(private);
414}
415
416static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
417{
418 return crypto_ahash_setkey(private, key, keylen);
419}
420
421static void hash_sock_destruct(struct sock *sk)
422{
423 struct alg_sock *ask = alg_sk(sk);
424 struct hash_ctx *ctx = ask->private;
425
426 hash_free_result(sk, ctx);
427 sock_kfree_s(sk, ctx, ctx->len);
428 af_alg_release_parent(sk);
429}
430
431static int hash_accept_parent_nokey(void *private, struct sock *sk)
432{
433 struct crypto_ahash *tfm = private;
434 struct alg_sock *ask = alg_sk(sk);
435 struct hash_ctx *ctx;
436 unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
437
438 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
439 if (!ctx)
440 return -ENOMEM;
441
442 ctx->result = NULL;
443 ctx->len = len;
444 ctx->more = 0;
445 crypto_init_wait(&ctx->wait);
446
447 ask->private = ctx;
448
449 ahash_request_set_tfm(&ctx->req, tfm);
450 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
451 crypto_req_done, &ctx->wait);
452
453 sk->sk_destruct = hash_sock_destruct;
454
455 return 0;
456}
457
458static int hash_accept_parent(void *private, struct sock *sk)
459{
460 struct crypto_ahash *tfm = private;
461
462 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
463 return -ENOKEY;
464
465 return hash_accept_parent_nokey(private, sk);
466}
467
468static const struct af_alg_type algif_type_hash = {
469 .bind = hash_bind,
470 .release = hash_release,
471 .setkey = hash_setkey,
472 .accept = hash_accept_parent,
473 .accept_nokey = hash_accept_parent_nokey,
474 .ops = &algif_hash_ops,
475 .ops_nokey = &algif_hash_ops_nokey,
476 .name = "hash",
477 .owner = THIS_MODULE
478};
479
480static int __init algif_hash_init(void)
481{
482 return af_alg_register_type(&algif_type_hash);
483}
484
485static void __exit algif_hash_exit(void)
486{
487 int err = af_alg_unregister_type(&algif_type_hash);
488 BUG_ON(err);
489}
490
491module_init(algif_hash_init);
492module_exit(algif_hash_exit);
493MODULE_LICENSE("GPL");
494