aboutsummaryrefslogtreecommitdiffstats
path: root/crypto/algif_hash.c
blob: 0a465e0f301291f3e63b4306905f25bcffa50284 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
/*
 * algif_hash: User-space interface for hash algorithms
 *
 * This file provides the user-space API for hash algorithms.
 *
 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/hash.h>
#include <crypto/if_alg.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/net.h>
#include <net/sock.h>

struct hash_ctx {
	struct af_alg_sgl sgl;

	u8 *result;

	struct af_alg_completion completion;

	unsigned int len;
	bool more;

	struct ahash_request req;
};

static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
			size_t ignored)
{
	int limit = ALG_MAX_PAGES * PAGE_SIZE;
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct hash_ctx *ctx = ask->private;
	long copied = 0;
	int err;

	if (limit > sk->sk_sndbuf)
		limit = sk->sk_sndbuf;

	lock_sock(sk);
	if (!ctx->more) {
		err = crypto_ahash_init(&ctx->req);
		if (err)
			goto unlock;
	}

	ctx->more = 0;

	while (iov_iter_count(&msg->msg_iter)) {
		int len = iov_iter_count(&msg->msg_iter);

		if (len > limit)
			len = limit;

		len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
		if (len < 0) {
			err = copied ? 0 : len;
			goto unlock;
		}

		ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);

		err = af_alg_wait_for_completion(crypto_ahash_update(&ctx->req),
						 &ctx->completion);
		af_alg_free_sg(&ctx->sgl);
		if (err)
			goto unlock;

		copied += len;
		iov_iter_advance(&msg->msg_iter, len);
	}

	err = 0;

	ctx->more = msg->msg_flags & MSG_MORE;
	if (!ctx->more) {
		ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
		err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
						 &ctx->completion);
	}

unlock:
	release_sock(sk);

	return err ?: copied;
}

static ssize_t hash_sendpage(struct socket *sock, struct page *page,
			     int offset, size_t size, int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct hash_ctx *ctx = ask->private;
	int err;

	if (flags & MSG_SENDPAGE_NOTLAST)
		flags |= MSG_MORE;

	lock_sock(sk);
	sg_init_table(ctx->sgl.sg, 1);
	sg_set_page(ctx->sgl.sg, page, size, offset);

	ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);

	if (!(flags & MSG_MORE)) {
		if (ctx->more)
			err = crypto_ahash_finup(&ctx->req);
		else
			err = crypto_ahash_digest(&ctx->req);
	} else {
		if (!ctx->more) {
			err = crypto_ahash_init(&ctx->req);
			if (err)
				goto unlock;
		}

		err = crypto_ahash_update(&ctx->req);
	}

	err = af_alg_wait_for_completion(err, &ctx->completion);
	if (err)
		goto unlock;

	ctx->more = flags & MSG_MORE;

unlock:
	release_sock(sk);

	return err ?: size;
}

static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
			int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct hash_ctx *ctx = ask->private;
	unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
	int err;

	if (len > ds)
		len = ds;
	else if (len < ds)
		msg->msg_flags |= MSG_TRUNC;

	lock_sock(sk);
	if (ctx->more) {
		ctx->more = 0;
		ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
		err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
						 &ctx->completion);
		if (err)
			goto unlock;
	}

	err = memcpy_to_msg(msg, ctx->result, len);

unlock:
	release_sock(sk);

	return err ?: len;
}

static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct sock *sk = sock->sk;
	struct alg_sock *ask = alg_sk(sk);
	struct hash_ctx *ctx = ask->private;
	struct ahash_request *req = &ctx->req;
	char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))];
	struct sock *sk2;
	struct alg_sock *ask2;
	struct hash_ctx *ctx2;
	int err;

	err = crypto_ahash_export(req, state);
	if (err)
		return err;

	err = af_alg_accept(ask->parent, newsock);
	if (err)
		return err;

	sk2 = newsock->sk;
	ask2 = alg_sk(sk2);
	ctx2 = ask2->private;
	ctx2->more = 1;

	err = crypto_ahash_import(&ctx2->req, state);
	if (err) {
		sock_orphan(sk2);
		sock_put(sk2);
	}

	return err;
}

static struct proto_ops algif_hash_ops = {
	.family		=	PF_ALG,

	.connect	=	sock_no_connect,
	.socketpair	=	sock_no_socketpair,
	.getname	=	sock_no_getname,
	.ioctl		=	sock_no_ioctl,
	.listen		=	sock_no_listen,
	.shutdown	=	sock_no_shutdown,
	.getsockopt	=	sock_no_getsockopt,
	.mmap		=	sock_no_mmap,
	.bind		=	sock_no_bind,
	.setsockopt	=	sock_no_setsockopt,
	.poll		=	sock_no_poll,

	.release	=	af_alg_release,
	.sendmsg	=	hash_sendmsg,
	.sendpage	=	hash_sendpage,
	.recvmsg	=	hash_recvmsg,
	.accept		=	hash_accept,
};

static void *hash_bind(const char *name, u32 type, u32 mask)
{
	return crypto_alloc_ahash(name, type, mask);
}

static void hash_release(void *private)
{
	crypto_free_ahash(private);
}

static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
{
	return crypto_ahash_setkey(private, key, keylen);
}

static void hash_sock_destruct(struct sock *sk)
{
	struct alg_sock *ask = alg_sk(sk);
	struct hash_ctx *ctx = ask->private;

	sock_kzfree_s(sk, ctx->result,
		      crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
	sock_kfree_s(sk, ctx, ctx->len);
	af_alg_release_parent(sk);
}

static int hash_accept_parent(void *private, struct sock *sk)
{
	struct hash_ctx *ctx;
	struct alg_sock *ask = alg_sk(sk);
	unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private);
	unsigned ds = crypto_ahash_digestsize(private);

	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
	if (!ctx->result) {
		sock_kfree_s(sk, ctx, len);
		return -ENOMEM;
	}

	memset(ctx->result, 0, ds);

	ctx->len = len;
	ctx->more = 0;
	af_alg_init_completion(&ctx->completion);

	ask->private = ctx;

	ahash_request_set_tfm(&ctx->req, private);
	ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
				   af_alg_complete, &ctx->completion);

	sk->sk_destruct = hash_sock_destruct;

	return 0;
}

static const struct af_alg_type algif_type_hash = {
	.bind		=	hash_bind,
	.release	=	hash_release,
	.setkey		=	hash_setkey,
	.accept		=	hash_accept_parent,
	.ops		=	&algif_hash_ops,
	.name		=	"hash",
	.owner		=	THIS_MODULE
};

static int __init algif_hash_init(void)
{
	return af_alg_register_type(&algif_type_hash);
}

static void __exit algif_hash_exit(void)
{
	int err = af_alg_unregister_type(&algif_type_hash);
	BUG_ON(err);
}

module_init(algif_hash_init);
module_exit(algif_hash_exit);
MODULE_LICENSE("GPL");