Commit | Line | Data |
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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 | |
bf63e250 DH |
12 | * filled by user space with the data submitted via sendmsg. Filling up the TX |
13 | * SGL does not cause a crypto operation -- the data will only be tracked by | |
14 | * the kernel. Upon receipt of one recvmsg call, the caller must provide a | |
15 | * buffer which is tracked with the RX SGL. | |
e870456d SM |
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 | ||
99bd99d3 HX |
50 | static int algif_skcipher_export(struct sock *sk, struct skcipher_request *req) |
51 | { | |
52 | struct alg_sock *ask = alg_sk(sk); | |
53 | struct crypto_skcipher *tfm; | |
54 | struct af_alg_ctx *ctx; | |
55 | struct alg_sock *pask; | |
56 | unsigned statesize; | |
57 | struct sock *psk; | |
58 | int err; | |
59 | ||
60 | if (!(req->base.flags & CRYPTO_SKCIPHER_REQ_NOTFINAL)) | |
61 | return 0; | |
62 | ||
63 | ctx = ask->private; | |
64 | psk = ask->parent; | |
65 | pask = alg_sk(psk); | |
66 | tfm = pask->private; | |
67 | ||
68 | statesize = crypto_skcipher_statesize(tfm); | |
69 | ctx->state = sock_kmalloc(sk, statesize, GFP_ATOMIC); | |
70 | if (!ctx->state) | |
71 | return -ENOMEM; | |
72 | ||
73 | err = crypto_skcipher_export(req, ctx->state); | |
74 | if (err) { | |
75 | sock_kzfree_s(sk, ctx->state, statesize); | |
76 | ctx->state = NULL; | |
77 | } | |
78 | ||
79 | return err; | |
80 | } | |
81 | ||
82 | static void algif_skcipher_done(void *data, int err) | |
83 | { | |
84 | struct af_alg_async_req *areq = data; | |
85 | struct sock *sk = areq->sk; | |
86 | ||
87 | if (err) | |
88 | goto out; | |
89 | ||
90 | err = algif_skcipher_export(sk, &areq->cra_u.skcipher_req); | |
91 | ||
92 | out: | |
93 | af_alg_async_cb(data, err); | |
94 | } | |
95 | ||
e870456d SM |
96 | static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg, |
97 | size_t ignored, int flags) | |
a596999b TS |
98 | { |
99 | struct sock *sk = sock->sk; | |
100 | struct alg_sock *ask = alg_sk(sk); | |
ec69bbfb HX |
101 | struct sock *psk = ask->parent; |
102 | struct alg_sock *pask = alg_sk(psk); | |
2d97591e | 103 | struct af_alg_ctx *ctx = ask->private; |
f8d33fac | 104 | struct crypto_skcipher *tfm = pask->private; |
5b0fe955 | 105 | unsigned int bs = crypto_skcipher_chunksize(tfm); |
2d97591e | 106 | struct af_alg_async_req *areq; |
99bd99d3 | 107 | unsigned cflags = 0; |
e870456d SM |
108 | int err = 0; |
109 | size_t len = 0; | |
ec69bbfb | 110 | |
f3c802a1 HX |
111 | if (!ctx->init || (ctx->more && ctx->used < bs)) { |
112 | err = af_alg_wait_for_data(sk, flags, bs); | |
11edb555 SM |
113 | if (err) |
114 | return err; | |
115 | } | |
116 | ||
e870456d | 117 | /* Allocate cipher request for current operation. */ |
2d97591e SM |
118 | areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) + |
119 | crypto_skcipher_reqsize(tfm)); | |
120 | if (IS_ERR(areq)) | |
121 | return PTR_ERR(areq); | |
a596999b | 122 | |
e870456d | 123 | /* convert iovecs of output buffers into RX SGL */ |
7cf81954 | 124 | err = af_alg_get_rsgl(sk, msg, flags, areq, ctx->used, &len); |
2d97591e SM |
125 | if (err) |
126 | goto free; | |
a596999b | 127 | |
e870456d SM |
128 | /* |
129 | * If more buffers are to be expected to be processed, process only | |
130 | * full block size buffers. | |
131 | */ | |
99bd99d3 | 132 | if (ctx->more || len < ctx->used) { |
e870456d | 133 | len -= len % bs; |
99bd99d3 HX |
134 | cflags |= CRYPTO_SKCIPHER_REQ_NOTFINAL; |
135 | } | |
e870456d SM |
136 | |
137 | /* | |
138 | * Create a per request TX SGL for this request which tracks the | |
139 | * SG entries from the global TX SGL. | |
140 | */ | |
2d97591e | 141 | areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0); |
e870456d SM |
142 | if (!areq->tsgl_entries) |
143 | areq->tsgl_entries = 1; | |
76e43e37 KC |
144 | areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl), |
145 | areq->tsgl_entries), | |
e870456d SM |
146 | GFP_KERNEL); |
147 | if (!areq->tsgl) { | |
148 | err = -ENOMEM; | |
149 | goto free; | |
150 | } | |
151 | sg_init_table(areq->tsgl, areq->tsgl_entries); | |
2d97591e | 152 | af_alg_pull_tsgl(sk, len, areq->tsgl, 0); |
e870456d SM |
153 | |
154 | /* Initialize the crypto operation */ | |
2d97591e SM |
155 | skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm); |
156 | skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl, | |
c1abe6f5 | 157 | areq->first_rsgl.sgl.sgt.sgl, len, ctx->iv); |
e870456d | 158 | |
99bd99d3 HX |
159 | if (ctx->state) { |
160 | err = crypto_skcipher_import(&areq->cra_u.skcipher_req, | |
161 | ctx->state); | |
162 | sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm)); | |
163 | ctx->state = NULL; | |
164 | if (err) | |
165 | goto free; | |
166 | cflags |= CRYPTO_SKCIPHER_REQ_CONT; | |
167 | } | |
168 | ||
e870456d SM |
169 | if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) { |
170 | /* AIO operation */ | |
7d2c3f54 | 171 | sock_hold(sk); |
e870456d | 172 | areq->iocb = msg->msg_iocb; |
d53c5135 SM |
173 | |
174 | /* Remember output size that will be generated. */ | |
175 | areq->outlen = len; | |
176 | ||
2d97591e | 177 | skcipher_request_set_callback(&areq->cra_u.skcipher_req, |
99bd99d3 | 178 | cflags | |
e870456d | 179 | CRYPTO_TFM_REQ_MAY_SLEEP, |
99bd99d3 | 180 | algif_skcipher_done, areq); |
2d97591e SM |
181 | err = ctx->enc ? |
182 | crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) : | |
183 | crypto_skcipher_decrypt(&areq->cra_u.skcipher_req); | |
7d2c3f54 SM |
184 | |
185 | /* AIO operation in progress */ | |
2a05b029 | 186 | if (err == -EINPROGRESS) |
7d2c3f54 | 187 | return -EIOCBQUEUED; |
7d2c3f54 SM |
188 | |
189 | sock_put(sk); | |
e870456d SM |
190 | } else { |
191 | /* Synchronous operation */ | |
2d97591e | 192 | skcipher_request_set_callback(&areq->cra_u.skcipher_req, |
99bd99d3 | 193 | cflags | |
e870456d SM |
194 | CRYPTO_TFM_REQ_MAY_SLEEP | |
195 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
2c3f8b16 GBY |
196 | crypto_req_done, &ctx->wait); |
197 | err = crypto_wait_req(ctx->enc ? | |
2d97591e SM |
198 | crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) : |
199 | crypto_skcipher_decrypt(&areq->cra_u.skcipher_req), | |
2c3f8b16 | 200 | &ctx->wait); |
033f46b3 | 201 | |
99bd99d3 HX |
202 | if (!err) |
203 | err = algif_skcipher_export( | |
204 | sk, &areq->cra_u.skcipher_req); | |
205 | } | |
e870456d | 206 | |
a596999b | 207 | free: |
7d2c3f54 | 208 | af_alg_free_resources(areq); |
e870456d SM |
209 | |
210 | return err ? err : len; | |
a596999b TS |
211 | } |
212 | ||
e870456d SM |
213 | static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg, |
214 | size_t ignored, int flags) | |
8ff59090 HX |
215 | { |
216 | struct sock *sk = sock->sk; | |
e870456d | 217 | int ret = 0; |
8ff59090 HX |
218 | |
219 | lock_sock(sk); | |
01e97e65 | 220 | while (msg_data_left(msg)) { |
e870456d SM |
221 | int err = _skcipher_recvmsg(sock, msg, ignored, flags); |
222 | ||
223 | /* | |
224 | * This error covers -EIOCBQUEUED which implies that we can | |
225 | * only handle one AIO request. If the caller wants to have | |
226 | * multiple AIO requests in parallel, he must make multiple | |
227 | * separate AIO calls. | |
5703c826 SM |
228 | * |
229 | * Also return the error if no data has been processed so far. | |
e870456d SM |
230 | */ |
231 | if (err <= 0) { | |
5703c826 | 232 | if (err == -EIOCBQUEUED || !ret) |
e870456d SM |
233 | ret = err; |
234 | goto out; | |
1d10eb2f AV |
235 | } |
236 | ||
e870456d | 237 | ret += err; |
8ff59090 HX |
238 | } |
239 | ||
e870456d | 240 | out: |
2d97591e | 241 | af_alg_wmem_wakeup(sk); |
8ff59090 | 242 | release_sock(sk); |
e870456d | 243 | return ret; |
a596999b | 244 | } |
8ff59090 | 245 | |
8ff59090 HX |
246 | static struct proto_ops algif_skcipher_ops = { |
247 | .family = PF_ALG, | |
248 | ||
249 | .connect = sock_no_connect, | |
250 | .socketpair = sock_no_socketpair, | |
251 | .getname = sock_no_getname, | |
252 | .ioctl = sock_no_ioctl, | |
253 | .listen = sock_no_listen, | |
254 | .shutdown = sock_no_shutdown, | |
8ff59090 HX |
255 | .mmap = sock_no_mmap, |
256 | .bind = sock_no_bind, | |
257 | .accept = sock_no_accept, | |
8ff59090 HX |
258 | |
259 | .release = af_alg_release, | |
260 | .sendmsg = skcipher_sendmsg, | |
8ff59090 | 261 | .recvmsg = skcipher_recvmsg, |
a11e1d43 | 262 | .poll = af_alg_poll, |
8ff59090 HX |
263 | }; |
264 | ||
a0fa2d03 HX |
265 | static int skcipher_check_key(struct socket *sock) |
266 | { | |
1822793a | 267 | int err = 0; |
a0fa2d03 HX |
268 | struct sock *psk; |
269 | struct alg_sock *pask; | |
f8d33fac | 270 | struct crypto_skcipher *tfm; |
a0fa2d03 HX |
271 | struct sock *sk = sock->sk; |
272 | struct alg_sock *ask = alg_sk(sk); | |
273 | ||
1822793a | 274 | lock_sock(sk); |
34c86f4c | 275 | if (!atomic_read(&ask->nokey_refcnt)) |
1822793a | 276 | goto unlock_child; |
a0fa2d03 HX |
277 | |
278 | psk = ask->parent; | |
279 | pask = alg_sk(ask->parent); | |
280 | tfm = pask->private; | |
281 | ||
282 | err = -ENOKEY; | |
1822793a | 283 | lock_sock_nested(psk, SINGLE_DEPTH_NESTING); |
f8d33fac | 284 | if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) |
a0fa2d03 HX |
285 | goto unlock; |
286 | ||
34c86f4c HX |
287 | atomic_dec(&pask->nokey_refcnt); |
288 | atomic_set(&ask->nokey_refcnt, 0); | |
a0fa2d03 HX |
289 | |
290 | err = 0; | |
291 | ||
292 | unlock: | |
293 | release_sock(psk); | |
1822793a HX |
294 | unlock_child: |
295 | release_sock(sk); | |
a0fa2d03 HX |
296 | |
297 | return err; | |
298 | } | |
299 | ||
300 | static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg, | |
301 | size_t size) | |
302 | { | |
303 | int err; | |
304 | ||
305 | err = skcipher_check_key(sock); | |
306 | if (err) | |
307 | return err; | |
308 | ||
309 | return skcipher_sendmsg(sock, msg, size); | |
310 | } | |
311 | ||
a0fa2d03 HX |
312 | static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg, |
313 | size_t ignored, int flags) | |
314 | { | |
315 | int err; | |
316 | ||
317 | err = skcipher_check_key(sock); | |
318 | if (err) | |
319 | return err; | |
320 | ||
321 | return skcipher_recvmsg(sock, msg, ignored, flags); | |
322 | } | |
323 | ||
324 | static struct proto_ops algif_skcipher_ops_nokey = { | |
325 | .family = PF_ALG, | |
326 | ||
327 | .connect = sock_no_connect, | |
328 | .socketpair = sock_no_socketpair, | |
329 | .getname = sock_no_getname, | |
330 | .ioctl = sock_no_ioctl, | |
331 | .listen = sock_no_listen, | |
332 | .shutdown = sock_no_shutdown, | |
a0fa2d03 HX |
333 | .mmap = sock_no_mmap, |
334 | .bind = sock_no_bind, | |
335 | .accept = sock_no_accept, | |
a0fa2d03 HX |
336 | |
337 | .release = af_alg_release, | |
338 | .sendmsg = skcipher_sendmsg_nokey, | |
a0fa2d03 | 339 | .recvmsg = skcipher_recvmsg_nokey, |
a11e1d43 | 340 | .poll = af_alg_poll, |
a0fa2d03 HX |
341 | }; |
342 | ||
8ff59090 HX |
343 | static void *skcipher_bind(const char *name, u32 type, u32 mask) |
344 | { | |
f8d33fac | 345 | return crypto_alloc_skcipher(name, type, mask); |
8ff59090 HX |
346 | } |
347 | ||
348 | static void skcipher_release(void *private) | |
349 | { | |
f8d33fac | 350 | crypto_free_skcipher(private); |
8ff59090 HX |
351 | } |
352 | ||
353 | static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen) | |
354 | { | |
f8d33fac | 355 | return crypto_skcipher_setkey(private, key, keylen); |
8ff59090 HX |
356 | } |
357 | ||
358 | static void skcipher_sock_destruct(struct sock *sk) | |
359 | { | |
360 | struct alg_sock *ask = alg_sk(sk); | |
2d97591e | 361 | struct af_alg_ctx *ctx = ask->private; |
e870456d SM |
362 | struct sock *psk = ask->parent; |
363 | struct alg_sock *pask = alg_sk(psk); | |
f8d33fac | 364 | struct crypto_skcipher *tfm = pask->private; |
a596999b | 365 | |
2d97591e | 366 | af_alg_pull_tsgl(sk, ctx->used, NULL, 0); |
0d96e4ba | 367 | sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm)); |
99bd99d3 HX |
368 | if (ctx->state) |
369 | sock_kzfree_s(sk, ctx->state, crypto_skcipher_statesize(tfm)); | |
8ff59090 HX |
370 | sock_kfree_s(sk, ctx, ctx->len); |
371 | af_alg_release_parent(sk); | |
372 | } | |
373 | ||
d7b65aee | 374 | static int skcipher_accept_parent_nokey(void *private, struct sock *sk) |
8ff59090 | 375 | { |
2d97591e | 376 | struct af_alg_ctx *ctx; |
8ff59090 | 377 | struct alg_sock *ask = alg_sk(sk); |
f8d33fac | 378 | struct crypto_skcipher *tfm = private; |
e870456d | 379 | unsigned int len = sizeof(*ctx); |
8ff59090 HX |
380 | |
381 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
382 | if (!ctx) | |
383 | return -ENOMEM; | |
21dfbcd1 | 384 | memset(ctx, 0, len); |
8ff59090 | 385 | |
f8d33fac | 386 | ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm), |
8ff59090 HX |
387 | GFP_KERNEL); |
388 | if (!ctx->iv) { | |
389 | sock_kfree_s(sk, ctx, len); | |
390 | return -ENOMEM; | |
391 | } | |
f8d33fac | 392 | memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm)); |
8ff59090 | 393 | |
e870456d | 394 | INIT_LIST_HEAD(&ctx->tsgl_list); |
8ff59090 | 395 | ctx->len = len; |
2c3f8b16 | 396 | crypto_init_wait(&ctx->wait); |
8ff59090 HX |
397 | |
398 | ask->private = ctx; | |
399 | ||
8ff59090 HX |
400 | sk->sk_destruct = skcipher_sock_destruct; |
401 | ||
402 | return 0; | |
403 | } | |
404 | ||
a0fa2d03 HX |
405 | static int skcipher_accept_parent(void *private, struct sock *sk) |
406 | { | |
f8d33fac | 407 | struct crypto_skcipher *tfm = private; |
a0fa2d03 | 408 | |
f8d33fac | 409 | if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) |
a0fa2d03 HX |
410 | return -ENOKEY; |
411 | ||
d7b65aee | 412 | return skcipher_accept_parent_nokey(private, sk); |
a0fa2d03 HX |
413 | } |
414 | ||
8ff59090 HX |
415 | static const struct af_alg_type algif_type_skcipher = { |
416 | .bind = skcipher_bind, | |
417 | .release = skcipher_release, | |
418 | .setkey = skcipher_setkey, | |
419 | .accept = skcipher_accept_parent, | |
a0fa2d03 | 420 | .accept_nokey = skcipher_accept_parent_nokey, |
8ff59090 | 421 | .ops = &algif_skcipher_ops, |
a0fa2d03 | 422 | .ops_nokey = &algif_skcipher_ops_nokey, |
8ff59090 HX |
423 | .name = "skcipher", |
424 | .owner = THIS_MODULE | |
425 | }; | |
426 | ||
427 | static int __init algif_skcipher_init(void) | |
428 | { | |
429 | return af_alg_register_type(&algif_type_skcipher); | |
430 | } | |
431 | ||
432 | static void __exit algif_skcipher_exit(void) | |
433 | { | |
434 | int err = af_alg_unregister_type(&algif_type_skcipher); | |
435 | BUG_ON(err); | |
436 | } | |
437 | ||
438 | module_init(algif_skcipher_init); | |
439 | module_exit(algif_skcipher_exit); | |
440 | MODULE_LICENSE("GPL"); |