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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
8ff59090 HX |
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 | * | |
e870456d SM |
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. | |
8ff59090 HX |
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 | ||
1b784140 YX |
37 | static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg, |
38 | size_t size) | |
8ff59090 HX |
39 | { |
40 | struct sock *sk = sock->sk; | |
41 | struct alg_sock *ask = alg_sk(sk); | |
6454c2b8 HX |
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); |
a596999b TS |
48 | } |
49 | ||
e870456d SM |
50 | static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg, |
51 | size_t ignored, int flags) | |
a596999b TS |
52 | { |
53 | struct sock *sk = sock->sk; | |
54 | struct alg_sock *ask = alg_sk(sk); | |
ec69bbfb HX |
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; |
e870456d SM |
61 | int err = 0; |
62 | size_t len = 0; | |
ec69bbfb | 63 | |
f3c802a1 HX |
64 | if (!ctx->init || (ctx->more && ctx->used < bs)) { |
65 | err = af_alg_wait_for_data(sk, flags, bs); | |
11edb555 SM |
66 | if (err) |
67 | return err; | |
68 | } | |
69 | ||
e870456d | 70 | /* Allocate cipher request for current operation. */ |
2d97591e SM |
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); |
2d97591e SM |
78 | if (err) |
79 | goto free; | |
a596999b | 80 | |
e870456d SM |
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); |
e870456d SM |
93 | if (!areq->tsgl_entries) |
94 | areq->tsgl_entries = 1; | |
76e43e37 KC |
95 | areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl), |
96 | areq->tsgl_entries), | |
e870456d SM |
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); |
e870456d SM |
104 | |
105 | /* Initialize the crypto operation */ | |
2d97591e SM |
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); | |
e870456d SM |
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; |
d53c5135 SM |
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, |
2d97591e SM |
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); | |
7d2c3f54 SM |
124 | |
125 | /* AIO operation in progress */ | |
d53c5135 | 126 | if (err == -EINPROGRESS || err == -EBUSY) |
7d2c3f54 | 127 | return -EIOCBQUEUED; |
7d2c3f54 SM |
128 | |
129 | sock_put(sk); | |
e870456d SM |
130 | } else { |
131 | /* Synchronous operation */ | |
2d97591e | 132 | skcipher_request_set_callback(&areq->cra_u.skcipher_req, |
e870456d SM |
133 | CRYPTO_TFM_REQ_MAY_SLEEP | |
134 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
2c3f8b16 GBY |
135 | crypto_req_done, &ctx->wait); |
136 | err = crypto_wait_req(ctx->enc ? | |
2d97591e SM |
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 | 143 | free: |
7d2c3f54 | 144 | af_alg_free_resources(areq); |
e870456d SM |
145 | |
146 | return err ? err : len; | |
a596999b TS |
147 | } |
148 | ||
e870456d SM |
149 | static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg, |
150 | size_t ignored, int flags) | |
8ff59090 HX |
151 | { |
152 | struct sock *sk = sock->sk; | |
e870456d | 153 | int ret = 0; |
8ff59090 HX |
154 | |
155 | lock_sock(sk); | |
01e97e65 | 156 | while (msg_data_left(msg)) { |
e870456d SM |
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. | |
5703c826 SM |
164 | * |
165 | * Also return the error if no data has been processed so far. | |
e870456d SM |
166 | */ |
167 | if (err <= 0) { | |
5703c826 | 168 | if (err == -EIOCBQUEUED || !ret) |
e870456d SM |
169 | ret = err; |
170 | goto out; | |
1d10eb2f AV |
171 | } |
172 | ||
e870456d | 173 | ret += err; |
8ff59090 HX |
174 | } |
175 | ||
e870456d | 176 | out: |
2d97591e | 177 | af_alg_wmem_wakeup(sk); |
8ff59090 | 178 | release_sock(sk); |
e870456d | 179 | return ret; |
a596999b | 180 | } |
8ff59090 | 181 | |
8ff59090 HX |
182 | static 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, | |
8ff59090 HX |
191 | .mmap = sock_no_mmap, |
192 | .bind = sock_no_bind, | |
193 | .accept = sock_no_accept, | |
8ff59090 HX |
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, |
8ff59090 HX |
200 | }; |
201 | ||
a0fa2d03 HX |
202 | static int skcipher_check_key(struct socket *sock) |
203 | { | |
1822793a | 204 | int err = 0; |
a0fa2d03 HX |
205 | struct sock *psk; |
206 | struct alg_sock *pask; | |
f8d33fac | 207 | struct crypto_skcipher *tfm; |
a0fa2d03 HX |
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; |
a0fa2d03 HX |
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) |
a0fa2d03 HX |
222 | goto unlock; |
223 | ||
34c86f4c HX |
224 | atomic_dec(&pask->nokey_refcnt); |
225 | atomic_set(&ask->nokey_refcnt, 0); | |
a0fa2d03 HX |
226 | |
227 | err = 0; | |
228 | ||
229 | unlock: | |
230 | release_sock(psk); | |
1822793a HX |
231 | unlock_child: |
232 | release_sock(sk); | |
a0fa2d03 HX |
233 | |
234 | return err; | |
235 | } | |
236 | ||
237 | static 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 | ||
249 | static 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); |
a0fa2d03 HX |
259 | } |
260 | ||
261 | static 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 | ||
273 | static 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, | |
a0fa2d03 HX |
282 | .mmap = sock_no_mmap, |
283 | .bind = sock_no_bind, | |
284 | .accept = sock_no_accept, | |
a0fa2d03 HX |
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, |
a0fa2d03 HX |
291 | }; |
292 | ||
8ff59090 HX |
293 | static void *skcipher_bind(const char *name, u32 type, u32 mask) |
294 | { | |
f8d33fac | 295 | return crypto_alloc_skcipher(name, type, mask); |
8ff59090 HX |
296 | } |
297 | ||
298 | static void skcipher_release(void *private) | |
299 | { | |
f8d33fac | 300 | crypto_free_skcipher(private); |
8ff59090 HX |
301 | } |
302 | ||
303 | static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen) | |
304 | { | |
f8d33fac | 305 | return crypto_skcipher_setkey(private, key, keylen); |
8ff59090 HX |
306 | } |
307 | ||
308 | static 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; |
e870456d SM |
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)); |
8ff59090 HX |
318 | sock_kfree_s(sk, ctx, ctx->len); |
319 | af_alg_release_parent(sk); | |
320 | } | |
321 | ||
d7b65aee | 322 | static 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); |
8ff59090 HX |
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), |
8ff59090 HX |
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); |
8ff59090 HX |
345 | |
346 | ask->private = ctx; | |
347 | ||
8ff59090 HX |
348 | sk->sk_destruct = skcipher_sock_destruct; |
349 | ||
350 | return 0; | |
351 | } | |
352 | ||
a0fa2d03 HX |
353 | static 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 HX |
358 | return -ENOKEY; |
359 | ||
d7b65aee | 360 | return skcipher_accept_parent_nokey(private, sk); |
a0fa2d03 HX |
361 | } |
362 | ||
8ff59090 HX |
363 | static 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, |
8ff59090 HX |
371 | .name = "skcipher", |
372 | .owner = THIS_MODULE | |
373 | }; | |
374 | ||
375 | static int __init algif_skcipher_init(void) | |
376 | { | |
377 | return af_alg_register_type(&algif_type_skcipher); | |
378 | } | |
379 | ||
380 | static void __exit algif_skcipher_exit(void) | |
381 | { | |
382 | int err = af_alg_unregister_type(&algif_type_skcipher); | |
383 | BUG_ON(err); | |
384 | } | |
385 | ||
386 | module_init(algif_skcipher_init); | |
387 | module_exit(algif_skcipher_exit); | |
388 | MODULE_LICENSE("GPL"); |