blob: 7e049ff6ae6045b2d3aae9433d8aef4cc8684563 [file] [log] [blame]
David Howells17926a72007-04-26 15:48:28 -07001/* RxRPC key management
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * RxRPC keys should have a description of describing their purpose:
12 * "afs@CAMBRIDGE.REDHAT.COM>
13 */
14
15#include <linux/module.h>
16#include <linux/net.h>
17#include <linux/skbuff.h>
18#include <linux/key.h>
19#include <linux/crypto.h>
20#include <net/sock.h>
21#include <net/af_rxrpc.h>
22#include <keys/rxrpc-type.h>
23#include <keys/user-type.h>
24#include "ar-internal.h"
25
26static int rxrpc_instantiate(struct key *, const void *, size_t);
27static int rxrpc_instantiate_s(struct key *, const void *, size_t);
28static void rxrpc_destroy(struct key *);
29static void rxrpc_destroy_s(struct key *);
30static void rxrpc_describe(const struct key *, struct seq_file *);
31
32/*
33 * rxrpc defined keys take an arbitrary string as the description and an
34 * arbitrary blob of data as the payload
35 */
36struct key_type key_type_rxrpc = {
37 .name = "rxrpc",
38 .instantiate = rxrpc_instantiate,
39 .match = user_match,
40 .destroy = rxrpc_destroy,
41 .describe = rxrpc_describe,
42};
43
44EXPORT_SYMBOL(key_type_rxrpc);
45
46/*
47 * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
48 * description and an 8-byte decryption key as the payload
49 */
50struct key_type key_type_rxrpc_s = {
51 .name = "rxrpc_s",
52 .instantiate = rxrpc_instantiate_s,
53 .match = user_match,
54 .destroy = rxrpc_destroy_s,
55 .describe = rxrpc_describe,
56};
57
58/*
59 * instantiate an rxrpc defined key
60 * data should be of the form:
61 * OFFSET LEN CONTENT
62 * 0 4 key interface version number
63 * 4 2 security index (type)
64 * 6 2 ticket length
65 * 8 4 key expiry time (time_t)
66 * 12 4 kvno
67 * 16 8 session key
68 * 24 [len] ticket
69 *
70 * if no data is provided, then a no-security key is made
71 */
72static int rxrpc_instantiate(struct key *key, const void *data, size_t datalen)
73{
74 const struct rxkad_key *tsec;
75 struct rxrpc_key_payload *upayload;
76 size_t plen;
77 u32 kver;
78 int ret;
79
80 _enter("{%x},,%zu", key_serial(key), datalen);
81
82 /* handle a no-security key */
83 if (!data && datalen == 0)
84 return 0;
85
86 /* get the key interface version number */
87 ret = -EINVAL;
88 if (datalen <= 4 || !data)
89 goto error;
90 memcpy(&kver, data, sizeof(kver));
91 data += sizeof(kver);
92 datalen -= sizeof(kver);
93
94 _debug("KEY I/F VERSION: %u", kver);
95
96 ret = -EKEYREJECTED;
97 if (kver != 1)
98 goto error;
99
100 /* deal with a version 1 key */
101 ret = -EINVAL;
102 if (datalen < sizeof(*tsec))
103 goto error;
104
105 tsec = data;
106 if (datalen != sizeof(*tsec) + tsec->ticket_len)
107 goto error;
108
109 _debug("SCIX: %u", tsec->security_index);
110 _debug("TLEN: %u", tsec->ticket_len);
111 _debug("EXPY: %x", tsec->expiry);
112 _debug("KVNO: %u", tsec->kvno);
113 _debug("SKEY: %02x%02x%02x%02x%02x%02x%02x%02x",
114 tsec->session_key[0], tsec->session_key[1],
115 tsec->session_key[2], tsec->session_key[3],
116 tsec->session_key[4], tsec->session_key[5],
117 tsec->session_key[6], tsec->session_key[7]);
118 if (tsec->ticket_len >= 8)
119 _debug("TCKT: %02x%02x%02x%02x%02x%02x%02x%02x",
120 tsec->ticket[0], tsec->ticket[1],
121 tsec->ticket[2], tsec->ticket[3],
122 tsec->ticket[4], tsec->ticket[5],
123 tsec->ticket[6], tsec->ticket[7]);
124
125 ret = -EPROTONOSUPPORT;
126 if (tsec->security_index != 2)
127 goto error;
128
129 key->type_data.x[0] = tsec->security_index;
130
131 plen = sizeof(*upayload) + tsec->ticket_len;
132 ret = key_payload_reserve(key, plen);
133 if (ret < 0)
134 goto error;
135
136 ret = -ENOMEM;
137 upayload = kmalloc(plen, GFP_KERNEL);
138 if (!upayload)
139 goto error;
140
141 /* attach the data */
142 memcpy(&upayload->k, tsec, sizeof(*tsec));
143 memcpy(&upayload->k.ticket, (void *)tsec + sizeof(*tsec),
144 tsec->ticket_len);
145 key->payload.data = upayload;
146 key->expiry = tsec->expiry;
147 ret = 0;
148
149error:
150 return ret;
151}
152
153/*
154 * instantiate a server secret key
155 * data should be a pointer to the 8-byte secret key
156 */
157static int rxrpc_instantiate_s(struct key *key, const void *data,
158 size_t datalen)
159{
160 struct crypto_blkcipher *ci;
161
162 _enter("{%x},,%zu", key_serial(key), datalen);
163
164 if (datalen != 8)
165 return -EINVAL;
166
167 memcpy(&key->type_data, data, 8);
168
169 ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
170 if (IS_ERR(ci)) {
171 _leave(" = %ld", PTR_ERR(ci));
172 return PTR_ERR(ci);
173 }
174
175 if (crypto_blkcipher_setkey(ci, data, 8) < 0)
176 BUG();
177
178 key->payload.data = ci;
179 _leave(" = 0");
180 return 0;
181}
182
183/*
184 * dispose of the data dangling from the corpse of a rxrpc key
185 */
186static void rxrpc_destroy(struct key *key)
187{
188 kfree(key->payload.data);
189}
190
191/*
192 * dispose of the data dangling from the corpse of a rxrpc key
193 */
194static void rxrpc_destroy_s(struct key *key)
195{
196 if (key->payload.data) {
197 crypto_free_blkcipher(key->payload.data);
198 key->payload.data = NULL;
199 }
200}
201
202/*
203 * describe the rxrpc key
204 */
205static void rxrpc_describe(const struct key *key, struct seq_file *m)
206{
207 seq_puts(m, key->description);
208}
209
210/*
211 * grab the security key for a socket
212 */
213int rxrpc_request_key(struct rxrpc_sock *rx, char __user *optval, int optlen)
214{
215 struct key *key;
216 char *description;
217
218 _enter("");
219
220 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
221 return -EINVAL;
222
223 description = kmalloc(optlen + 1, GFP_KERNEL);
224 if (!description)
225 return -ENOMEM;
226
227 if (copy_from_user(description, optval, optlen)) {
228 kfree(description);
229 return -EFAULT;
230 }
231 description[optlen] = 0;
232
233 key = request_key(&key_type_rxrpc, description, NULL);
234 if (IS_ERR(key)) {
235 kfree(description);
236 _leave(" = %ld", PTR_ERR(key));
237 return PTR_ERR(key);
238 }
239
240 rx->key = key;
241 kfree(description);
242 _leave(" = 0 [key %x]", key->serial);
243 return 0;
244}
245
246/*
247 * grab the security keyring for a server socket
248 */
249int rxrpc_server_keyring(struct rxrpc_sock *rx, char __user *optval,
250 int optlen)
251{
252 struct key *key;
253 char *description;
254
255 _enter("");
256
257 if (optlen <= 0 || optlen > PAGE_SIZE - 1)
258 return -EINVAL;
259
260 description = kmalloc(optlen + 1, GFP_KERNEL);
261 if (!description)
262 return -ENOMEM;
263
264 if (copy_from_user(description, optval, optlen)) {
265 kfree(description);
266 return -EFAULT;
267 }
268 description[optlen] = 0;
269
270 key = request_key(&key_type_keyring, description, NULL);
271 if (IS_ERR(key)) {
272 kfree(description);
273 _leave(" = %ld", PTR_ERR(key));
274 return PTR_ERR(key);
275 }
276
277 rx->securities = key;
278 kfree(description);
279 _leave(" = 0 [key %x]", key->serial);
280 return 0;
281}
282
283/*
284 * generate a server data key
285 */
286int rxrpc_get_server_data_key(struct rxrpc_connection *conn,
287 const void *session_key,
288 time_t expiry,
289 u32 kvno)
290{
291 struct key *key;
292 int ret;
293
294 struct {
295 u32 kver;
296 struct rxkad_key tsec;
297 } data;
298
299 _enter("");
300
301 key = key_alloc(&key_type_rxrpc, "x", 0, 0, current, 0,
302 KEY_ALLOC_NOT_IN_QUOTA);
303 if (IS_ERR(key)) {
304 _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
305 return -ENOMEM;
306 }
307
308 _debug("key %d", key_serial(key));
309
310 data.kver = 1;
311 data.tsec.security_index = 2;
312 data.tsec.ticket_len = 0;
313 data.tsec.expiry = expiry;
314 data.tsec.kvno = 0;
315
316 memcpy(&data.tsec.session_key, session_key,
317 sizeof(data.tsec.session_key));
318
319 ret = key_instantiate_and_link(key, &data, sizeof(data), NULL, NULL);
320 if (ret < 0)
321 goto error;
322
323 conn->key = key;
324 _leave(" = 0 [%d]", key_serial(key));
325 return 0;
326
327error:
328 key_revoke(key);
329 key_put(key);
330 _leave(" = -ENOMEM [ins %d]", ret);
331 return -ENOMEM;
332}
333
334EXPORT_SYMBOL(rxrpc_get_server_data_key);