Commit | Line | Data |
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1da177e4 LT |
1 | /* user_defined.c: user defined key type |
2 | * | |
3 | * Copyright (C) 2004 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 | ||
12 | #include <linux/module.h> | |
13 | #include <linux/init.h> | |
1da177e4 LT |
14 | #include <linux/slab.h> |
15 | #include <linux/seq_file.h> | |
16 | #include <linux/err.h> | |
2aa349f6 | 17 | #include <keys/user-type.h> |
1da177e4 LT |
18 | #include <asm/uaccess.h> |
19 | #include "internal.h" | |
20 | ||
9f6ed2ca JL |
21 | static int logon_vet_description(const char *desc); |
22 | ||
1da177e4 LT |
23 | /* |
24 | * user defined keys take an arbitrary string as the description and an | |
25 | * arbitrary blob of data as the payload | |
26 | */ | |
27 | struct key_type key_type_user = { | |
4bdf0bc3 DH |
28 | .name = "user", |
29 | .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, | |
30 | .instantiate = user_instantiate, | |
31 | .update = user_update, | |
32 | .match = user_match, | |
33 | .revoke = user_revoke, | |
34 | .destroy = user_destroy, | |
35 | .describe = user_describe, | |
36 | .read = user_read, | |
1da177e4 LT |
37 | }; |
38 | ||
16c29b67 MH |
39 | EXPORT_SYMBOL_GPL(key_type_user); |
40 | ||
9f6ed2ca JL |
41 | /* |
42 | * This key type is essentially the same as key_type_user, but it does | |
43 | * not define a .read op. This is suitable for storing username and | |
44 | * password pairs in the keyring that you do not want to be readable | |
45 | * from userspace. | |
46 | */ | |
47 | struct key_type key_type_logon = { | |
48 | .name = "logon", | |
4bdf0bc3 | 49 | .def_lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, |
9f6ed2ca JL |
50 | .instantiate = user_instantiate, |
51 | .update = user_update, | |
52 | .match = user_match, | |
53 | .revoke = user_revoke, | |
54 | .destroy = user_destroy, | |
55 | .describe = user_describe, | |
56 | .vet_description = logon_vet_description, | |
57 | }; | |
58 | EXPORT_SYMBOL_GPL(key_type_logon); | |
59 | ||
1da177e4 LT |
60 | /* |
61 | * instantiate a user defined key | |
62 | */ | |
cf7f601c | 63 | int user_instantiate(struct key *key, struct key_preparsed_payload *prep) |
1da177e4 | 64 | { |
76d8aeab | 65 | struct user_key_payload *upayload; |
cf7f601c | 66 | size_t datalen = prep->datalen; |
1da177e4 LT |
67 | int ret; |
68 | ||
69 | ret = -EINVAL; | |
cf7f601c | 70 | if (datalen <= 0 || datalen > 32767 || !prep->data) |
1da177e4 LT |
71 | goto error; |
72 | ||
73 | ret = key_payload_reserve(key, datalen); | |
74 | if (ret < 0) | |
75 | goto error; | |
76 | ||
1da177e4 | 77 | ret = -ENOMEM; |
76d8aeab DH |
78 | upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); |
79 | if (!upayload) | |
1da177e4 LT |
80 | goto error; |
81 | ||
76d8aeab DH |
82 | /* attach the data */ |
83 | upayload->datalen = datalen; | |
cf7f601c | 84 | memcpy(upayload->data, prep->data, datalen); |
f6b24579 | 85 | rcu_assign_keypointer(key, upayload); |
1da177e4 LT |
86 | ret = 0; |
87 | ||
2aa349f6 | 88 | error: |
1da177e4 | 89 | return ret; |
a8b17ed0 | 90 | } |
31204ed9 | 91 | |
2aa349f6 DH |
92 | EXPORT_SYMBOL_GPL(user_instantiate); |
93 | ||
1da177e4 LT |
94 | /* |
95 | * update a user defined key | |
76d8aeab | 96 | * - the key's semaphore is write-locked |
1da177e4 | 97 | */ |
cf7f601c | 98 | int user_update(struct key *key, struct key_preparsed_payload *prep) |
1da177e4 | 99 | { |
76d8aeab | 100 | struct user_key_payload *upayload, *zap; |
cf7f601c | 101 | size_t datalen = prep->datalen; |
1da177e4 LT |
102 | int ret; |
103 | ||
104 | ret = -EINVAL; | |
cf7f601c | 105 | if (datalen <= 0 || datalen > 32767 || !prep->data) |
1da177e4 LT |
106 | goto error; |
107 | ||
76d8aeab | 108 | /* construct a replacement payload */ |
1da177e4 | 109 | ret = -ENOMEM; |
76d8aeab DH |
110 | upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL); |
111 | if (!upayload) | |
1da177e4 LT |
112 | goto error; |
113 | ||
76d8aeab | 114 | upayload->datalen = datalen; |
cf7f601c | 115 | memcpy(upayload->data, prep->data, datalen); |
1da177e4 LT |
116 | |
117 | /* check the quota and attach the new data */ | |
76d8aeab | 118 | zap = upayload; |
1da177e4 LT |
119 | |
120 | ret = key_payload_reserve(key, datalen); | |
121 | ||
122 | if (ret == 0) { | |
123 | /* attach the new data, displacing the old */ | |
124 | zap = key->payload.data; | |
f6b24579 | 125 | rcu_assign_keypointer(key, upayload); |
1da177e4 LT |
126 | key->expiry = 0; |
127 | } | |
128 | ||
9f35a33b DH |
129 | if (zap) |
130 | kfree_rcu(zap, rcu); | |
1da177e4 | 131 | |
2aa349f6 | 132 | error: |
1da177e4 | 133 | return ret; |
a8b17ed0 | 134 | } |
1da177e4 | 135 | |
2aa349f6 DH |
136 | EXPORT_SYMBOL_GPL(user_update); |
137 | ||
1da177e4 LT |
138 | /* |
139 | * match users on their name | |
140 | */ | |
2aa349f6 | 141 | int user_match(const struct key *key, const void *description) |
1da177e4 LT |
142 | { |
143 | return strcmp(key->description, description) == 0; | |
a8b17ed0 | 144 | } |
1da177e4 | 145 | |
2aa349f6 DH |
146 | EXPORT_SYMBOL_GPL(user_match); |
147 | ||
1da177e4 | 148 | /* |
31204ed9 DH |
149 | * dispose of the links from a revoked keyring |
150 | * - called with the key sem write-locked | |
151 | */ | |
152 | void user_revoke(struct key *key) | |
153 | { | |
154 | struct user_key_payload *upayload = key->payload.data; | |
155 | ||
156 | /* clear the quota */ | |
157 | key_payload_reserve(key, 0); | |
158 | ||
159 | if (upayload) { | |
f6b24579 | 160 | rcu_assign_keypointer(key, NULL); |
3acb458c | 161 | kfree_rcu(upayload, rcu); |
31204ed9 | 162 | } |
a8b17ed0 | 163 | } |
31204ed9 DH |
164 | |
165 | EXPORT_SYMBOL(user_revoke); | |
166 | ||
31204ed9 DH |
167 | /* |
168 | * dispose of the data dangling from the corpse of a user key | |
1da177e4 | 169 | */ |
2aa349f6 | 170 | void user_destroy(struct key *key) |
1da177e4 | 171 | { |
76d8aeab DH |
172 | struct user_key_payload *upayload = key->payload.data; |
173 | ||
174 | kfree(upayload); | |
a8b17ed0 | 175 | } |
1da177e4 | 176 | |
2aa349f6 DH |
177 | EXPORT_SYMBOL_GPL(user_destroy); |
178 | ||
1da177e4 | 179 | /* |
76d8aeab | 180 | * describe the user key |
1da177e4 | 181 | */ |
2aa349f6 | 182 | void user_describe(const struct key *key, struct seq_file *m) |
1da177e4 LT |
183 | { |
184 | seq_puts(m, key->description); | |
78b7280c DH |
185 | if (key_is_instantiated(key)) |
186 | seq_printf(m, ": %u", key->datalen); | |
a8b17ed0 | 187 | } |
1da177e4 | 188 | |
2aa349f6 DH |
189 | EXPORT_SYMBOL_GPL(user_describe); |
190 | ||
1da177e4 LT |
191 | /* |
192 | * read the key data | |
76d8aeab | 193 | * - the key's semaphore is read-locked |
1da177e4 | 194 | */ |
2aa349f6 | 195 | long user_read(const struct key *key, char __user *buffer, size_t buflen) |
1da177e4 | 196 | { |
76d8aeab DH |
197 | struct user_key_payload *upayload; |
198 | long ret; | |
199 | ||
633e804e | 200 | upayload = rcu_dereference_key(key); |
76d8aeab | 201 | ret = upayload->datalen; |
1da177e4 LT |
202 | |
203 | /* we can return the data as is */ | |
204 | if (buffer && buflen > 0) { | |
76d8aeab DH |
205 | if (buflen > upayload->datalen) |
206 | buflen = upayload->datalen; | |
1da177e4 | 207 | |
76d8aeab | 208 | if (copy_to_user(buffer, upayload->data, buflen) != 0) |
1da177e4 LT |
209 | ret = -EFAULT; |
210 | } | |
211 | ||
212 | return ret; | |
a8b17ed0 | 213 | } |
2aa349f6 DH |
214 | |
215 | EXPORT_SYMBOL_GPL(user_read); | |
9f6ed2ca JL |
216 | |
217 | /* Vet the description for a "logon" key */ | |
218 | static int logon_vet_description(const char *desc) | |
219 | { | |
220 | char *p; | |
221 | ||
222 | /* require a "qualified" description string */ | |
223 | p = strchr(desc, ':'); | |
224 | if (!p) | |
225 | return -EINVAL; | |
226 | ||
227 | /* also reject description with ':' as first char */ | |
228 | if (p == desc) | |
229 | return -EINVAL; | |
230 | ||
231 | return 0; | |
232 | } |