Merge tag 'asoc-fix-v5.11-rc2' of https://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-block.git] / crypto / algif_skcipher.c
CommitLineData
2874c5fd 1// SPDX-License-Identifier: GPL-2.0-or-later
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2/*
3 * algif_skcipher: User-space interface for skcipher algorithms
4 *
5 * This file provides the user-space API for symmetric key ciphers.
6 *
7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
8 *
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9 * The following concept of the memory management is used:
10 *
11 * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
12 * filled by user space with the data submitted via sendpage/sendmsg. Filling
13 * up the TX SGL does not cause a crypto operation -- the data will only be
14 * tracked by the kernel. Upon receipt of one recvmsg call, the caller must
15 * provide a buffer which is tracked with the RX SGL.
16 *
17 * During the processing of the recvmsg operation, the cipher request is
18 * allocated and prepared. As part of the recvmsg operation, the processed
19 * TX buffers are extracted from the TX SGL into a separate SGL.
20 *
21 * After the completion of the crypto operation, the RX SGL and the cipher
22 * request is released. The extracted TX SGL parts are released together with
23 * the RX SGL release.
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24 */
25
26#include <crypto/scatterwalk.h>
27#include <crypto/skcipher.h>
28#include <crypto/if_alg.h>
29#include <linux/init.h>
30#include <linux/list.h>
31#include <linux/kernel.h>
32#include <linux/mm.h>
33#include <linux/module.h>
34#include <linux/net.h>
35#include <net/sock.h>
36
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37static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg,
38 size_t size)
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39{
40 struct sock *sk = sock->sk;
41 struct alg_sock *ask = alg_sk(sk);
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42 struct sock *psk = ask->parent;
43 struct alg_sock *pask = alg_sk(psk);
f8d33fac 44 struct crypto_skcipher *tfm = pask->private;
0d96e4ba 45 unsigned ivsize = crypto_skcipher_ivsize(tfm);
8ff59090 46
2d97591e 47 return af_alg_sendmsg(sock, msg, size, ivsize);
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48}
49
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50static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
51 size_t ignored, int flags)
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52{
53 struct sock *sk = sock->sk;
54 struct alg_sock *ask = alg_sk(sk);
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55 struct sock *psk = ask->parent;
56 struct alg_sock *pask = alg_sk(psk);
2d97591e 57 struct af_alg_ctx *ctx = ask->private;
f8d33fac 58 struct crypto_skcipher *tfm = pask->private;
5b0fe955 59 unsigned int bs = crypto_skcipher_chunksize(tfm);
2d97591e 60 struct af_alg_async_req *areq;
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61 int err = 0;
62 size_t len = 0;
ec69bbfb 63
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64 if (!ctx->init || (ctx->more && ctx->used < bs)) {
65 err = af_alg_wait_for_data(sk, flags, bs);
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66 if (err)
67 return err;
68 }
69
e870456d 70 /* Allocate cipher request for current operation. */
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71 areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
72 crypto_skcipher_reqsize(tfm));
73 if (IS_ERR(areq))
74 return PTR_ERR(areq);
a596999b 75
e870456d 76 /* convert iovecs of output buffers into RX SGL */
7cf81954 77 err = af_alg_get_rsgl(sk, msg, flags, areq, ctx->used, &len);
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78 if (err)
79 goto free;
a596999b 80
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81 /*
82 * If more buffers are to be expected to be processed, process only
83 * full block size buffers.
84 */
85 if (ctx->more || len < ctx->used)
86 len -= len % bs;
87
88 /*
89 * Create a per request TX SGL for this request which tracks the
90 * SG entries from the global TX SGL.
91 */
2d97591e 92 areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0);
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93 if (!areq->tsgl_entries)
94 areq->tsgl_entries = 1;
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95 areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
96 areq->tsgl_entries),
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97 GFP_KERNEL);
98 if (!areq->tsgl) {
99 err = -ENOMEM;
100 goto free;
101 }
102 sg_init_table(areq->tsgl, areq->tsgl_entries);
2d97591e 103 af_alg_pull_tsgl(sk, len, areq->tsgl, 0);
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104
105 /* Initialize the crypto operation */
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106 skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm);
107 skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl,
108 areq->first_rsgl.sgl.sg, len, ctx->iv);
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109
110 if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
111 /* AIO operation */
7d2c3f54 112 sock_hold(sk);
e870456d 113 areq->iocb = msg->msg_iocb;
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114
115 /* Remember output size that will be generated. */
116 areq->outlen = len;
117
2d97591e 118 skcipher_request_set_callback(&areq->cra_u.skcipher_req,
e870456d 119 CRYPTO_TFM_REQ_MAY_SLEEP,
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120 af_alg_async_cb, areq);
121 err = ctx->enc ?
122 crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
123 crypto_skcipher_decrypt(&areq->cra_u.skcipher_req);
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124
125 /* AIO operation in progress */
2a05b029 126 if (err == -EINPROGRESS)
7d2c3f54 127 return -EIOCBQUEUED;
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128
129 sock_put(sk);
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130 } else {
131 /* Synchronous operation */
2d97591e 132 skcipher_request_set_callback(&areq->cra_u.skcipher_req,
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133 CRYPTO_TFM_REQ_MAY_SLEEP |
134 CRYPTO_TFM_REQ_MAY_BACKLOG,
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135 crypto_req_done, &ctx->wait);
136 err = crypto_wait_req(ctx->enc ?
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137 crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) :
138 crypto_skcipher_decrypt(&areq->cra_u.skcipher_req),
2c3f8b16 139 &ctx->wait);
e870456d 140 }
033f46b3 141
e870456d 142
a596999b 143free:
7d2c3f54 144 af_alg_free_resources(areq);
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145
146 return err ? err : len;
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147}
148
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149static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg,
150 size_t ignored, int flags)
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151{
152 struct sock *sk = sock->sk;
e870456d 153 int ret = 0;
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154
155 lock_sock(sk);
01e97e65 156 while (msg_data_left(msg)) {
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157 int err = _skcipher_recvmsg(sock, msg, ignored, flags);
158
159 /*
160 * This error covers -EIOCBQUEUED which implies that we can
161 * only handle one AIO request. If the caller wants to have
162 * multiple AIO requests in parallel, he must make multiple
163 * separate AIO calls.
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164 *
165 * Also return the error if no data has been processed so far.
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166 */
167 if (err <= 0) {
5703c826 168 if (err == -EIOCBQUEUED || !ret)
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169 ret = err;
170 goto out;
1d10eb2f
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171 }
172
e870456d 173 ret += err;
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174 }
175
e870456d 176out:
2d97591e 177 af_alg_wmem_wakeup(sk);
8ff59090 178 release_sock(sk);
e870456d 179 return ret;
a596999b 180}
8ff59090 181
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182static struct proto_ops algif_skcipher_ops = {
183 .family = PF_ALG,
184
185 .connect = sock_no_connect,
186 .socketpair = sock_no_socketpair,
187 .getname = sock_no_getname,
188 .ioctl = sock_no_ioctl,
189 .listen = sock_no_listen,
190 .shutdown = sock_no_shutdown,
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191 .mmap = sock_no_mmap,
192 .bind = sock_no_bind,
193 .accept = sock_no_accept,
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194
195 .release = af_alg_release,
196 .sendmsg = skcipher_sendmsg,
2d97591e 197 .sendpage = af_alg_sendpage,
8ff59090 198 .recvmsg = skcipher_recvmsg,
a11e1d43 199 .poll = af_alg_poll,
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200};
201
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202static int skcipher_check_key(struct socket *sock)
203{
1822793a 204 int err = 0;
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205 struct sock *psk;
206 struct alg_sock *pask;
f8d33fac 207 struct crypto_skcipher *tfm;
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208 struct sock *sk = sock->sk;
209 struct alg_sock *ask = alg_sk(sk);
210
1822793a 211 lock_sock(sk);
34c86f4c 212 if (!atomic_read(&ask->nokey_refcnt))
1822793a 213 goto unlock_child;
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214
215 psk = ask->parent;
216 pask = alg_sk(ask->parent);
217 tfm = pask->private;
218
219 err = -ENOKEY;
1822793a 220 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
f8d33fac 221 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
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222 goto unlock;
223
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224 atomic_dec(&pask->nokey_refcnt);
225 atomic_set(&ask->nokey_refcnt, 0);
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226
227 err = 0;
228
229unlock:
230 release_sock(psk);
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231unlock_child:
232 release_sock(sk);
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233
234 return err;
235}
236
237static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
238 size_t size)
239{
240 int err;
241
242 err = skcipher_check_key(sock);
243 if (err)
244 return err;
245
246 return skcipher_sendmsg(sock, msg, size);
247}
248
249static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page,
250 int offset, size_t size, int flags)
251{
252 int err;
253
254 err = skcipher_check_key(sock);
255 if (err)
256 return err;
257
2d97591e 258 return af_alg_sendpage(sock, page, offset, size, flags);
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259}
260
261static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
262 size_t ignored, int flags)
263{
264 int err;
265
266 err = skcipher_check_key(sock);
267 if (err)
268 return err;
269
270 return skcipher_recvmsg(sock, msg, ignored, flags);
271}
272
273static struct proto_ops algif_skcipher_ops_nokey = {
274 .family = PF_ALG,
275
276 .connect = sock_no_connect,
277 .socketpair = sock_no_socketpair,
278 .getname = sock_no_getname,
279 .ioctl = sock_no_ioctl,
280 .listen = sock_no_listen,
281 .shutdown = sock_no_shutdown,
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282 .mmap = sock_no_mmap,
283 .bind = sock_no_bind,
284 .accept = sock_no_accept,
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285
286 .release = af_alg_release,
287 .sendmsg = skcipher_sendmsg_nokey,
288 .sendpage = skcipher_sendpage_nokey,
289 .recvmsg = skcipher_recvmsg_nokey,
a11e1d43 290 .poll = af_alg_poll,
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291};
292
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293static void *skcipher_bind(const char *name, u32 type, u32 mask)
294{
f8d33fac 295 return crypto_alloc_skcipher(name, type, mask);
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296}
297
298static void skcipher_release(void *private)
299{
f8d33fac 300 crypto_free_skcipher(private);
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301}
302
303static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen)
304{
f8d33fac 305 return crypto_skcipher_setkey(private, key, keylen);
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306}
307
308static void skcipher_sock_destruct(struct sock *sk)
309{
310 struct alg_sock *ask = alg_sk(sk);
2d97591e 311 struct af_alg_ctx *ctx = ask->private;
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312 struct sock *psk = ask->parent;
313 struct alg_sock *pask = alg_sk(psk);
f8d33fac 314 struct crypto_skcipher *tfm = pask->private;
a596999b 315
2d97591e 316 af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
0d96e4ba 317 sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm));
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318 sock_kfree_s(sk, ctx, ctx->len);
319 af_alg_release_parent(sk);
320}
321
d7b65aee 322static int skcipher_accept_parent_nokey(void *private, struct sock *sk)
8ff59090 323{
2d97591e 324 struct af_alg_ctx *ctx;
8ff59090 325 struct alg_sock *ask = alg_sk(sk);
f8d33fac 326 struct crypto_skcipher *tfm = private;
e870456d 327 unsigned int len = sizeof(*ctx);
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328
329 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
330 if (!ctx)
331 return -ENOMEM;
21dfbcd1 332 memset(ctx, 0, len);
8ff59090 333
f8d33fac 334 ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm),
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335 GFP_KERNEL);
336 if (!ctx->iv) {
337 sock_kfree_s(sk, ctx, len);
338 return -ENOMEM;
339 }
f8d33fac 340 memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm));
8ff59090 341
e870456d 342 INIT_LIST_HEAD(&ctx->tsgl_list);
8ff59090 343 ctx->len = len;
2c3f8b16 344 crypto_init_wait(&ctx->wait);
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345
346 ask->private = ctx;
347
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348 sk->sk_destruct = skcipher_sock_destruct;
349
350 return 0;
351}
352
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353static int skcipher_accept_parent(void *private, struct sock *sk)
354{
f8d33fac 355 struct crypto_skcipher *tfm = private;
a0fa2d03 356
f8d33fac 357 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
a0fa2d03
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358 return -ENOKEY;
359
d7b65aee 360 return skcipher_accept_parent_nokey(private, sk);
a0fa2d03
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361}
362
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363static const struct af_alg_type algif_type_skcipher = {
364 .bind = skcipher_bind,
365 .release = skcipher_release,
366 .setkey = skcipher_setkey,
367 .accept = skcipher_accept_parent,
a0fa2d03 368 .accept_nokey = skcipher_accept_parent_nokey,
8ff59090 369 .ops = &algif_skcipher_ops,
a0fa2d03 370 .ops_nokey = &algif_skcipher_ops_nokey,
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371 .name = "skcipher",
372 .owner = THIS_MODULE
373};
374
375static int __init algif_skcipher_init(void)
376{
377 return af_alg_register_type(&algif_type_skcipher);
378}
379
380static void __exit algif_skcipher_exit(void)
381{
382 int err = af_alg_unregister_type(&algif_type_skcipher);
383 BUG_ON(err);
384}
385
386module_init(algif_skcipher_init);
387module_exit(algif_skcipher_exit);
388MODULE_LICENSE("GPL");