Commit | Line | Data |
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8ff59090 HX |
1 | /* |
2 | * algif_skcipher: User-space interface for skcipher algorithms | |
3 | * | |
4 | * This file provides the user-space API for symmetric key ciphers. | |
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 | * | |
e870456d SM |
13 | * The following concept of the memory management is used: |
14 | * | |
15 | * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is | |
16 | * filled by user space with the data submitted via sendpage/sendmsg. Filling | |
17 | * up the TX SGL does not cause a crypto operation -- the data will only be | |
18 | * tracked by the kernel. Upon receipt of one recvmsg call, the caller must | |
19 | * provide a buffer which is tracked with the RX SGL. | |
20 | * | |
21 | * During the processing of the recvmsg operation, the cipher request is | |
22 | * allocated and prepared. As part of the recvmsg operation, the processed | |
23 | * TX buffers are extracted from the TX SGL into a separate SGL. | |
24 | * | |
25 | * After the completion of the crypto operation, the RX SGL and the cipher | |
26 | * request is released. The extracted TX SGL parts are released together with | |
27 | * the RX SGL release. | |
8ff59090 HX |
28 | */ |
29 | ||
30 | #include <crypto/scatterwalk.h> | |
31 | #include <crypto/skcipher.h> | |
32 | #include <crypto/if_alg.h> | |
33 | #include <linux/init.h> | |
34 | #include <linux/list.h> | |
35 | #include <linux/kernel.h> | |
36 | #include <linux/mm.h> | |
37 | #include <linux/module.h> | |
38 | #include <linux/net.h> | |
39 | #include <net/sock.h> | |
40 | ||
1b784140 YX |
41 | static int skcipher_sendmsg(struct socket *sock, struct msghdr *msg, |
42 | size_t size) | |
8ff59090 HX |
43 | { |
44 | struct sock *sk = sock->sk; | |
45 | struct alg_sock *ask = alg_sk(sk); | |
6454c2b8 HX |
46 | struct sock *psk = ask->parent; |
47 | struct alg_sock *pask = alg_sk(psk); | |
f8d33fac | 48 | struct crypto_skcipher *tfm = pask->private; |
0d96e4ba | 49 | unsigned ivsize = crypto_skcipher_ivsize(tfm); |
8ff59090 | 50 | |
2d97591e | 51 | return af_alg_sendmsg(sock, msg, size, ivsize); |
a596999b TS |
52 | } |
53 | ||
e870456d SM |
54 | static int _skcipher_recvmsg(struct socket *sock, struct msghdr *msg, |
55 | size_t ignored, int flags) | |
a596999b TS |
56 | { |
57 | struct sock *sk = sock->sk; | |
58 | struct alg_sock *ask = alg_sk(sk); | |
ec69bbfb HX |
59 | struct sock *psk = ask->parent; |
60 | struct alg_sock *pask = alg_sk(psk); | |
2d97591e | 61 | struct af_alg_ctx *ctx = ask->private; |
f8d33fac | 62 | struct crypto_skcipher *tfm = pask->private; |
e870456d | 63 | unsigned int bs = crypto_skcipher_blocksize(tfm); |
2d97591e | 64 | struct af_alg_async_req *areq; |
e870456d SM |
65 | int err = 0; |
66 | size_t len = 0; | |
ec69bbfb | 67 | |
11edb555 SM |
68 | if (!ctx->used) { |
69 | err = af_alg_wait_for_data(sk, flags); | |
70 | if (err) | |
71 | return err; | |
72 | } | |
73 | ||
e870456d | 74 | /* Allocate cipher request for current operation. */ |
2d97591e SM |
75 | areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) + |
76 | crypto_skcipher_reqsize(tfm)); | |
77 | if (IS_ERR(areq)) | |
78 | return PTR_ERR(areq); | |
a596999b | 79 | |
e870456d | 80 | /* convert iovecs of output buffers into RX SGL */ |
2d97591e SM |
81 | err = af_alg_get_rsgl(sk, msg, flags, areq, -1, &len); |
82 | if (err) | |
83 | goto free; | |
a596999b | 84 | |
e870456d SM |
85 | /* Process only as much RX buffers for which we have TX data */ |
86 | if (len > ctx->used) | |
87 | len = ctx->used; | |
88 | ||
89 | /* | |
90 | * If more buffers are to be expected to be processed, process only | |
91 | * full block size buffers. | |
92 | */ | |
93 | if (ctx->more || len < ctx->used) | |
94 | len -= len % bs; | |
95 | ||
96 | /* | |
97 | * Create a per request TX SGL for this request which tracks the | |
98 | * SG entries from the global TX SGL. | |
99 | */ | |
2d97591e | 100 | areq->tsgl_entries = af_alg_count_tsgl(sk, len, 0); |
e870456d SM |
101 | if (!areq->tsgl_entries) |
102 | areq->tsgl_entries = 1; | |
103 | areq->tsgl = sock_kmalloc(sk, sizeof(*areq->tsgl) * areq->tsgl_entries, | |
104 | GFP_KERNEL); | |
105 | if (!areq->tsgl) { | |
106 | err = -ENOMEM; | |
107 | goto free; | |
108 | } | |
109 | sg_init_table(areq->tsgl, areq->tsgl_entries); | |
2d97591e | 110 | af_alg_pull_tsgl(sk, len, areq->tsgl, 0); |
e870456d SM |
111 | |
112 | /* Initialize the crypto operation */ | |
2d97591e SM |
113 | skcipher_request_set_tfm(&areq->cra_u.skcipher_req, tfm); |
114 | skcipher_request_set_crypt(&areq->cra_u.skcipher_req, areq->tsgl, | |
115 | areq->first_rsgl.sgl.sg, len, ctx->iv); | |
e870456d SM |
116 | |
117 | if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) { | |
118 | /* AIO operation */ | |
7d2c3f54 | 119 | sock_hold(sk); |
e870456d | 120 | areq->iocb = msg->msg_iocb; |
d53c5135 SM |
121 | |
122 | /* Remember output size that will be generated. */ | |
123 | areq->outlen = len; | |
124 | ||
2d97591e | 125 | skcipher_request_set_callback(&areq->cra_u.skcipher_req, |
e870456d | 126 | CRYPTO_TFM_REQ_MAY_SLEEP, |
2d97591e SM |
127 | af_alg_async_cb, areq); |
128 | err = ctx->enc ? | |
129 | crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) : | |
130 | crypto_skcipher_decrypt(&areq->cra_u.skcipher_req); | |
7d2c3f54 SM |
131 | |
132 | /* AIO operation in progress */ | |
d53c5135 | 133 | if (err == -EINPROGRESS || err == -EBUSY) |
7d2c3f54 | 134 | return -EIOCBQUEUED; |
7d2c3f54 SM |
135 | |
136 | sock_put(sk); | |
e870456d SM |
137 | } else { |
138 | /* Synchronous operation */ | |
2d97591e | 139 | skcipher_request_set_callback(&areq->cra_u.skcipher_req, |
e870456d SM |
140 | CRYPTO_TFM_REQ_MAY_SLEEP | |
141 | CRYPTO_TFM_REQ_MAY_BACKLOG, | |
2c3f8b16 GBY |
142 | crypto_req_done, &ctx->wait); |
143 | err = crypto_wait_req(ctx->enc ? | |
2d97591e SM |
144 | crypto_skcipher_encrypt(&areq->cra_u.skcipher_req) : |
145 | crypto_skcipher_decrypt(&areq->cra_u.skcipher_req), | |
2c3f8b16 | 146 | &ctx->wait); |
e870456d | 147 | } |
033f46b3 | 148 | |
e870456d | 149 | |
a596999b | 150 | free: |
7d2c3f54 | 151 | af_alg_free_resources(areq); |
e870456d SM |
152 | |
153 | return err ? err : len; | |
a596999b TS |
154 | } |
155 | ||
e870456d SM |
156 | static int skcipher_recvmsg(struct socket *sock, struct msghdr *msg, |
157 | size_t ignored, int flags) | |
8ff59090 HX |
158 | { |
159 | struct sock *sk = sock->sk; | |
e870456d | 160 | int ret = 0; |
8ff59090 HX |
161 | |
162 | lock_sock(sk); | |
01e97e65 | 163 | while (msg_data_left(msg)) { |
e870456d SM |
164 | int err = _skcipher_recvmsg(sock, msg, ignored, flags); |
165 | ||
166 | /* | |
167 | * This error covers -EIOCBQUEUED which implies that we can | |
168 | * only handle one AIO request. If the caller wants to have | |
169 | * multiple AIO requests in parallel, he must make multiple | |
170 | * separate AIO calls. | |
5703c826 SM |
171 | * |
172 | * Also return the error if no data has been processed so far. | |
e870456d SM |
173 | */ |
174 | if (err <= 0) { | |
5703c826 | 175 | if (err == -EIOCBQUEUED || !ret) |
e870456d SM |
176 | ret = err; |
177 | goto out; | |
1d10eb2f AV |
178 | } |
179 | ||
e870456d | 180 | ret += err; |
8ff59090 HX |
181 | } |
182 | ||
e870456d | 183 | out: |
2d97591e | 184 | af_alg_wmem_wakeup(sk); |
8ff59090 | 185 | release_sock(sk); |
e870456d | 186 | return ret; |
a596999b | 187 | } |
8ff59090 | 188 | |
8ff59090 HX |
189 | static struct proto_ops algif_skcipher_ops = { |
190 | .family = PF_ALG, | |
191 | ||
192 | .connect = sock_no_connect, | |
193 | .socketpair = sock_no_socketpair, | |
194 | .getname = sock_no_getname, | |
195 | .ioctl = sock_no_ioctl, | |
196 | .listen = sock_no_listen, | |
197 | .shutdown = sock_no_shutdown, | |
198 | .getsockopt = sock_no_getsockopt, | |
199 | .mmap = sock_no_mmap, | |
200 | .bind = sock_no_bind, | |
201 | .accept = sock_no_accept, | |
202 | .setsockopt = sock_no_setsockopt, | |
203 | ||
204 | .release = af_alg_release, | |
205 | .sendmsg = skcipher_sendmsg, | |
2d97591e | 206 | .sendpage = af_alg_sendpage, |
8ff59090 | 207 | .recvmsg = skcipher_recvmsg, |
2d97591e | 208 | .poll = af_alg_poll, |
8ff59090 HX |
209 | }; |
210 | ||
a0fa2d03 HX |
211 | static int skcipher_check_key(struct socket *sock) |
212 | { | |
1822793a | 213 | int err = 0; |
a0fa2d03 HX |
214 | struct sock *psk; |
215 | struct alg_sock *pask; | |
f8d33fac | 216 | struct crypto_skcipher *tfm; |
a0fa2d03 HX |
217 | struct sock *sk = sock->sk; |
218 | struct alg_sock *ask = alg_sk(sk); | |
219 | ||
1822793a | 220 | lock_sock(sk); |
a0fa2d03 | 221 | if (ask->refcnt) |
1822793a | 222 | goto unlock_child; |
a0fa2d03 HX |
223 | |
224 | psk = ask->parent; | |
225 | pask = alg_sk(ask->parent); | |
226 | tfm = pask->private; | |
227 | ||
228 | err = -ENOKEY; | |
1822793a | 229 | lock_sock_nested(psk, SINGLE_DEPTH_NESTING); |
f8d33fac | 230 | if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) |
a0fa2d03 HX |
231 | goto unlock; |
232 | ||
233 | if (!pask->refcnt++) | |
234 | sock_hold(psk); | |
235 | ||
236 | ask->refcnt = 1; | |
237 | sock_put(psk); | |
238 | ||
239 | err = 0; | |
240 | ||
241 | unlock: | |
242 | release_sock(psk); | |
1822793a HX |
243 | unlock_child: |
244 | release_sock(sk); | |
a0fa2d03 HX |
245 | |
246 | return err; | |
247 | } | |
248 | ||
249 | static int skcipher_sendmsg_nokey(struct socket *sock, struct msghdr *msg, | |
250 | size_t size) | |
251 | { | |
252 | int err; | |
253 | ||
254 | err = skcipher_check_key(sock); | |
255 | if (err) | |
256 | return err; | |
257 | ||
258 | return skcipher_sendmsg(sock, msg, size); | |
259 | } | |
260 | ||
261 | static ssize_t skcipher_sendpage_nokey(struct socket *sock, struct page *page, | |
262 | int offset, size_t size, int flags) | |
263 | { | |
264 | int err; | |
265 | ||
266 | err = skcipher_check_key(sock); | |
267 | if (err) | |
268 | return err; | |
269 | ||
2d97591e | 270 | return af_alg_sendpage(sock, page, offset, size, flags); |
a0fa2d03 HX |
271 | } |
272 | ||
273 | static int skcipher_recvmsg_nokey(struct socket *sock, struct msghdr *msg, | |
274 | size_t ignored, int flags) | |
275 | { | |
276 | int err; | |
277 | ||
278 | err = skcipher_check_key(sock); | |
279 | if (err) | |
280 | return err; | |
281 | ||
282 | return skcipher_recvmsg(sock, msg, ignored, flags); | |
283 | } | |
284 | ||
285 | static struct proto_ops algif_skcipher_ops_nokey = { | |
286 | .family = PF_ALG, | |
287 | ||
288 | .connect = sock_no_connect, | |
289 | .socketpair = sock_no_socketpair, | |
290 | .getname = sock_no_getname, | |
291 | .ioctl = sock_no_ioctl, | |
292 | .listen = sock_no_listen, | |
293 | .shutdown = sock_no_shutdown, | |
294 | .getsockopt = sock_no_getsockopt, | |
295 | .mmap = sock_no_mmap, | |
296 | .bind = sock_no_bind, | |
297 | .accept = sock_no_accept, | |
298 | .setsockopt = sock_no_setsockopt, | |
299 | ||
300 | .release = af_alg_release, | |
301 | .sendmsg = skcipher_sendmsg_nokey, | |
302 | .sendpage = skcipher_sendpage_nokey, | |
303 | .recvmsg = skcipher_recvmsg_nokey, | |
2d97591e | 304 | .poll = af_alg_poll, |
a0fa2d03 HX |
305 | }; |
306 | ||
8ff59090 HX |
307 | static void *skcipher_bind(const char *name, u32 type, u32 mask) |
308 | { | |
f8d33fac | 309 | return crypto_alloc_skcipher(name, type, mask); |
8ff59090 HX |
310 | } |
311 | ||
312 | static void skcipher_release(void *private) | |
313 | { | |
f8d33fac | 314 | crypto_free_skcipher(private); |
8ff59090 HX |
315 | } |
316 | ||
317 | static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen) | |
318 | { | |
f8d33fac | 319 | return crypto_skcipher_setkey(private, key, keylen); |
8ff59090 HX |
320 | } |
321 | ||
322 | static void skcipher_sock_destruct(struct sock *sk) | |
323 | { | |
324 | struct alg_sock *ask = alg_sk(sk); | |
2d97591e | 325 | struct af_alg_ctx *ctx = ask->private; |
e870456d SM |
326 | struct sock *psk = ask->parent; |
327 | struct alg_sock *pask = alg_sk(psk); | |
f8d33fac | 328 | struct crypto_skcipher *tfm = pask->private; |
a596999b | 329 | |
2d97591e | 330 | af_alg_pull_tsgl(sk, ctx->used, NULL, 0); |
0d96e4ba | 331 | sock_kzfree_s(sk, ctx->iv, crypto_skcipher_ivsize(tfm)); |
8ff59090 HX |
332 | sock_kfree_s(sk, ctx, ctx->len); |
333 | af_alg_release_parent(sk); | |
334 | } | |
335 | ||
d7b65aee | 336 | static int skcipher_accept_parent_nokey(void *private, struct sock *sk) |
8ff59090 | 337 | { |
2d97591e | 338 | struct af_alg_ctx *ctx; |
8ff59090 | 339 | struct alg_sock *ask = alg_sk(sk); |
f8d33fac | 340 | struct crypto_skcipher *tfm = private; |
e870456d | 341 | unsigned int len = sizeof(*ctx); |
8ff59090 HX |
342 | |
343 | ctx = sock_kmalloc(sk, len, GFP_KERNEL); | |
344 | if (!ctx) | |
345 | return -ENOMEM; | |
346 | ||
f8d33fac | 347 | ctx->iv = sock_kmalloc(sk, crypto_skcipher_ivsize(tfm), |
8ff59090 HX |
348 | GFP_KERNEL); |
349 | if (!ctx->iv) { | |
350 | sock_kfree_s(sk, ctx, len); | |
351 | return -ENOMEM; | |
352 | } | |
353 | ||
f8d33fac | 354 | memset(ctx->iv, 0, crypto_skcipher_ivsize(tfm)); |
8ff59090 | 355 | |
e870456d | 356 | INIT_LIST_HEAD(&ctx->tsgl_list); |
8ff59090 HX |
357 | ctx->len = len; |
358 | ctx->used = 0; | |
af955bf1 | 359 | atomic_set(&ctx->rcvused, 0); |
8ff59090 HX |
360 | ctx->more = 0; |
361 | ctx->merge = 0; | |
362 | ctx->enc = 0; | |
2c3f8b16 | 363 | crypto_init_wait(&ctx->wait); |
8ff59090 HX |
364 | |
365 | ask->private = ctx; | |
366 | ||
8ff59090 HX |
367 | sk->sk_destruct = skcipher_sock_destruct; |
368 | ||
369 | return 0; | |
370 | } | |
371 | ||
a0fa2d03 HX |
372 | static int skcipher_accept_parent(void *private, struct sock *sk) |
373 | { | |
f8d33fac | 374 | struct crypto_skcipher *tfm = private; |
a0fa2d03 | 375 | |
f8d33fac | 376 | if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) |
a0fa2d03 HX |
377 | return -ENOKEY; |
378 | ||
d7b65aee | 379 | return skcipher_accept_parent_nokey(private, sk); |
a0fa2d03 HX |
380 | } |
381 | ||
8ff59090 HX |
382 | static const struct af_alg_type algif_type_skcipher = { |
383 | .bind = skcipher_bind, | |
384 | .release = skcipher_release, | |
385 | .setkey = skcipher_setkey, | |
386 | .accept = skcipher_accept_parent, | |
a0fa2d03 | 387 | .accept_nokey = skcipher_accept_parent_nokey, |
8ff59090 | 388 | .ops = &algif_skcipher_ops, |
a0fa2d03 | 389 | .ops_nokey = &algif_skcipher_ops_nokey, |
8ff59090 HX |
390 | .name = "skcipher", |
391 | .owner = THIS_MODULE | |
392 | }; | |
393 | ||
394 | static int __init algif_skcipher_init(void) | |
395 | { | |
396 | return af_alg_register_type(&algif_type_skcipher); | |
397 | } | |
398 | ||
399 | static void __exit algif_skcipher_exit(void) | |
400 | { | |
401 | int err = af_alg_unregister_type(&algif_type_skcipher); | |
402 | BUG_ON(err); | |
403 | } | |
404 | ||
405 | module_init(algif_skcipher_init); | |
406 | module_exit(algif_skcipher_exit); | |
407 | MODULE_LICENSE("GPL"); |