Root/
1 | /* request_key_auth.c: request key authorisation controlling key def |
2 | * |
3 | * Copyright (C) 2005 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 | * See Documentation/keys-request-key.txt |
12 | */ |
13 | |
14 | #include <linux/module.h> |
15 | #include <linux/sched.h> |
16 | #include <linux/err.h> |
17 | #include <linux/seq_file.h> |
18 | #include <linux/slab.h> |
19 | #include <asm/uaccess.h> |
20 | #include "internal.h" |
21 | |
22 | static int request_key_auth_instantiate(struct key *, const void *, size_t); |
23 | static void request_key_auth_describe(const struct key *, struct seq_file *); |
24 | static void request_key_auth_revoke(struct key *); |
25 | static void request_key_auth_destroy(struct key *); |
26 | static long request_key_auth_read(const struct key *, char __user *, size_t); |
27 | |
28 | /* |
29 | * the request-key authorisation key type definition |
30 | */ |
31 | struct key_type key_type_request_key_auth = { |
32 | .name = ".request_key_auth", |
33 | .def_datalen = sizeof(struct request_key_auth), |
34 | .instantiate = request_key_auth_instantiate, |
35 | .describe = request_key_auth_describe, |
36 | .revoke = request_key_auth_revoke, |
37 | .destroy = request_key_auth_destroy, |
38 | .read = request_key_auth_read, |
39 | }; |
40 | |
41 | /*****************************************************************************/ |
42 | /* |
43 | * instantiate a request-key authorisation key |
44 | */ |
45 | static int request_key_auth_instantiate(struct key *key, |
46 | const void *data, |
47 | size_t datalen) |
48 | { |
49 | key->payload.data = (struct request_key_auth *) data; |
50 | return 0; |
51 | |
52 | } /* end request_key_auth_instantiate() */ |
53 | |
54 | /*****************************************************************************/ |
55 | /* |
56 | * reading a request-key authorisation key retrieves the callout information |
57 | */ |
58 | static void request_key_auth_describe(const struct key *key, |
59 | struct seq_file *m) |
60 | { |
61 | struct request_key_auth *rka = key->payload.data; |
62 | |
63 | seq_puts(m, "key:"); |
64 | seq_puts(m, key->description); |
65 | seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len); |
66 | |
67 | } /* end request_key_auth_describe() */ |
68 | |
69 | /*****************************************************************************/ |
70 | /* |
71 | * read the callout_info data |
72 | * - the key's semaphore is read-locked |
73 | */ |
74 | static long request_key_auth_read(const struct key *key, |
75 | char __user *buffer, size_t buflen) |
76 | { |
77 | struct request_key_auth *rka = key->payload.data; |
78 | size_t datalen; |
79 | long ret; |
80 | |
81 | datalen = rka->callout_len; |
82 | ret = datalen; |
83 | |
84 | /* we can return the data as is */ |
85 | if (buffer && buflen > 0) { |
86 | if (buflen > datalen) |
87 | buflen = datalen; |
88 | |
89 | if (copy_to_user(buffer, rka->callout_info, buflen) != 0) |
90 | ret = -EFAULT; |
91 | } |
92 | |
93 | return ret; |
94 | |
95 | } /* end request_key_auth_read() */ |
96 | |
97 | /*****************************************************************************/ |
98 | /* |
99 | * handle revocation of an authorisation token key |
100 | * - called with the key sem write-locked |
101 | */ |
102 | static void request_key_auth_revoke(struct key *key) |
103 | { |
104 | struct request_key_auth *rka = key->payload.data; |
105 | |
106 | kenter("{%d}", key->serial); |
107 | |
108 | if (rka->cred) { |
109 | put_cred(rka->cred); |
110 | rka->cred = NULL; |
111 | } |
112 | |
113 | } /* end request_key_auth_revoke() */ |
114 | |
115 | /*****************************************************************************/ |
116 | /* |
117 | * destroy an instantiation authorisation token key |
118 | */ |
119 | static void request_key_auth_destroy(struct key *key) |
120 | { |
121 | struct request_key_auth *rka = key->payload.data; |
122 | |
123 | kenter("{%d}", key->serial); |
124 | |
125 | if (rka->cred) { |
126 | put_cred(rka->cred); |
127 | rka->cred = NULL; |
128 | } |
129 | |
130 | key_put(rka->target_key); |
131 | key_put(rka->dest_keyring); |
132 | kfree(rka->callout_info); |
133 | kfree(rka); |
134 | |
135 | } /* end request_key_auth_destroy() */ |
136 | |
137 | /*****************************************************************************/ |
138 | /* |
139 | * create an authorisation token for /sbin/request-key or whoever to gain |
140 | * access to the caller's security data |
141 | */ |
142 | struct key *request_key_auth_new(struct key *target, const void *callout_info, |
143 | size_t callout_len, struct key *dest_keyring) |
144 | { |
145 | struct request_key_auth *rka, *irka; |
146 | const struct cred *cred = current->cred; |
147 | struct key *authkey = NULL; |
148 | char desc[20]; |
149 | int ret; |
150 | |
151 | kenter("%d,", target->serial); |
152 | |
153 | /* allocate a auth record */ |
154 | rka = kmalloc(sizeof(*rka), GFP_KERNEL); |
155 | if (!rka) { |
156 | kleave(" = -ENOMEM"); |
157 | return ERR_PTR(-ENOMEM); |
158 | } |
159 | rka->callout_info = kmalloc(callout_len, GFP_KERNEL); |
160 | if (!rka->callout_info) { |
161 | kleave(" = -ENOMEM"); |
162 | kfree(rka); |
163 | return ERR_PTR(-ENOMEM); |
164 | } |
165 | |
166 | /* see if the calling process is already servicing the key request of |
167 | * another process */ |
168 | if (cred->request_key_auth) { |
169 | /* it is - use that instantiation context here too */ |
170 | down_read(&cred->request_key_auth->sem); |
171 | |
172 | /* if the auth key has been revoked, then the key we're |
173 | * servicing is already instantiated */ |
174 | if (test_bit(KEY_FLAG_REVOKED, &cred->request_key_auth->flags)) |
175 | goto auth_key_revoked; |
176 | |
177 | irka = cred->request_key_auth->payload.data; |
178 | rka->cred = get_cred(irka->cred); |
179 | rka->pid = irka->pid; |
180 | |
181 | up_read(&cred->request_key_auth->sem); |
182 | } |
183 | else { |
184 | /* it isn't - use this process as the context */ |
185 | rka->cred = get_cred(cred); |
186 | rka->pid = current->pid; |
187 | } |
188 | |
189 | rka->target_key = key_get(target); |
190 | rka->dest_keyring = key_get(dest_keyring); |
191 | memcpy(rka->callout_info, callout_info, callout_len); |
192 | rka->callout_len = callout_len; |
193 | |
194 | /* allocate the auth key */ |
195 | sprintf(desc, "%x", target->serial); |
196 | |
197 | authkey = key_alloc(&key_type_request_key_auth, desc, |
198 | cred->fsuid, cred->fsgid, cred, |
199 | KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH | |
200 | KEY_USR_VIEW, KEY_ALLOC_NOT_IN_QUOTA); |
201 | if (IS_ERR(authkey)) { |
202 | ret = PTR_ERR(authkey); |
203 | goto error_alloc; |
204 | } |
205 | |
206 | /* construct the auth key */ |
207 | ret = key_instantiate_and_link(authkey, rka, 0, NULL, NULL); |
208 | if (ret < 0) |
209 | goto error_inst; |
210 | |
211 | kleave(" = {%d,%d}", authkey->serial, atomic_read(&authkey->usage)); |
212 | return authkey; |
213 | |
214 | auth_key_revoked: |
215 | up_read(&cred->request_key_auth->sem); |
216 | kfree(rka->callout_info); |
217 | kfree(rka); |
218 | kleave("= -EKEYREVOKED"); |
219 | return ERR_PTR(-EKEYREVOKED); |
220 | |
221 | error_inst: |
222 | key_revoke(authkey); |
223 | key_put(authkey); |
224 | error_alloc: |
225 | key_put(rka->target_key); |
226 | key_put(rka->dest_keyring); |
227 | kfree(rka->callout_info); |
228 | kfree(rka); |
229 | kleave("= %d", ret); |
230 | return ERR_PTR(ret); |
231 | |
232 | } /* end request_key_auth_new() */ |
233 | |
234 | /*****************************************************************************/ |
235 | /* |
236 | * see if an authorisation key is associated with a particular key |
237 | */ |
238 | static int key_get_instantiation_authkey_match(const struct key *key, |
239 | const void *_id) |
240 | { |
241 | struct request_key_auth *rka = key->payload.data; |
242 | key_serial_t id = (key_serial_t)(unsigned long) _id; |
243 | |
244 | return rka->target_key->serial == id; |
245 | |
246 | } /* end key_get_instantiation_authkey_match() */ |
247 | |
248 | /*****************************************************************************/ |
249 | /* |
250 | * get the authorisation key for instantiation of a specific key if attached to |
251 | * the current process's keyrings |
252 | * - this key is inserted into a keyring and that is set as /sbin/request-key's |
253 | * session keyring |
254 | * - a target_id of zero specifies any valid token |
255 | */ |
256 | struct key *key_get_instantiation_authkey(key_serial_t target_id) |
257 | { |
258 | const struct cred *cred = current_cred(); |
259 | struct key *authkey; |
260 | key_ref_t authkey_ref; |
261 | |
262 | authkey_ref = search_process_keyrings( |
263 | &key_type_request_key_auth, |
264 | (void *) (unsigned long) target_id, |
265 | key_get_instantiation_authkey_match, |
266 | cred); |
267 | |
268 | if (IS_ERR(authkey_ref)) { |
269 | authkey = ERR_CAST(authkey_ref); |
270 | goto error; |
271 | } |
272 | |
273 | authkey = key_ref_to_ptr(authkey_ref); |
274 | if (test_bit(KEY_FLAG_REVOKED, &authkey->flags)) { |
275 | key_put(authkey); |
276 | authkey = ERR_PTR(-EKEYREVOKED); |
277 | } |
278 | |
279 | error: |
280 | return authkey; |
281 | |
282 | } /* end key_get_instantiation_authkey() */ |
283 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9