KEYS: Separate the kernel signature checking keyring from module signing
[linux-2.6-block.git] / include / linux / key.h
CommitLineData
76181c13 1/* Authentication token and access key management
1da177e4 2 *
76181c13 3 * Copyright (C) 2004, 2007 Red Hat, Inc. All Rights Reserved.
1da177e4
LT
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 *
d410fa4e 12 * See Documentation/security/keys.txt for information on keys/keyrings.
1da177e4
LT
13 */
14
15#ifndef _LINUX_KEY_H
16#define _LINUX_KEY_H
17
18#include <linux/types.h>
19#include <linux/list.h>
20#include <linux/rbtree.h>
76d8aeab 21#include <linux/rcupdate.h>
0b77f5bf 22#include <linux/sysctl.h>
aa84442d 23#include <linux/rwsem.h>
60063497 24#include <linux/atomic.h>
b2a4df20 25#include <linux/assoc_array.h>
1da177e4
LT
26
27#ifdef __KERNEL__
9a56c2db 28#include <linux/uidgid.h>
1da177e4
LT
29
30/* key handle serial number */
31typedef int32_t key_serial_t;
32
33/* key handle permissions mask */
34typedef uint32_t key_perm_t;
35
36struct key;
37
38#ifdef CONFIG_KEYS
39
40#undef KEY_DEBUGGING
41
664cceb0
DH
42#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
43#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
44#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
45#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
46#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
29db9190
DH
47#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
48#define KEY_POS_ALL 0x3f000000
664cceb0
DH
49
50#define KEY_USR_VIEW 0x00010000 /* user permissions... */
51#define KEY_USR_READ 0x00020000
52#define KEY_USR_WRITE 0x00040000
53#define KEY_USR_SEARCH 0x00080000
54#define KEY_USR_LINK 0x00100000
29db9190
DH
55#define KEY_USR_SETATTR 0x00200000
56#define KEY_USR_ALL 0x003f0000
1da177e4
LT
57
58#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
59#define KEY_GRP_READ 0x00000200
60#define KEY_GRP_WRITE 0x00000400
61#define KEY_GRP_SEARCH 0x00000800
62#define KEY_GRP_LINK 0x00001000
29db9190
DH
63#define KEY_GRP_SETATTR 0x00002000
64#define KEY_GRP_ALL 0x00003f00
1da177e4
LT
65
66#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
67#define KEY_OTH_READ 0x00000002
68#define KEY_OTH_WRITE 0x00000004
69#define KEY_OTH_SEARCH 0x00000008
70#define KEY_OTH_LINK 0x00000010
29db9190
DH
71#define KEY_OTH_SETATTR 0x00000020
72#define KEY_OTH_ALL 0x0000003f
1da177e4 73
6b79ccb5
AR
74#define KEY_PERM_UNDEF 0xffffffff
75
1da177e4
LT
76struct seq_file;
77struct user_struct;
78struct signal_struct;
d84f4f99 79struct cred;
1da177e4
LT
80
81struct key_type;
82struct key_owner;
83struct keyring_list;
84struct keyring_name;
85
16feef43
DH
86struct keyring_index_key {
87 struct key_type *type;
88 const char *description;
89 size_t desc_len;
90};
91
664cceb0
DH
92/*****************************************************************************/
93/*
94 * key reference with possession attribute handling
95 *
96 * NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
97 * defined. This is because we abuse the bottom bit of the reference to carry a
98 * flag to indicate whether the calling process possesses that key in one of
99 * its keyrings.
100 *
101 * the key_ref_t has been made a separate type so that the compiler can reject
102 * attempts to dereference it without proper conversion.
103 *
104 * the three functions are used to assemble and disassemble references
105 */
106typedef struct __key_reference_with_attributes *key_ref_t;
107
108static inline key_ref_t make_key_ref(const struct key *key,
a5b4bd28 109 bool possession)
664cceb0
DH
110{
111 return (key_ref_t) ((unsigned long) key | possession);
112}
113
114static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
115{
116 return (struct key *) ((unsigned long) key_ref & ~1UL);
117}
118
a5b4bd28 119static inline bool is_key_possessed(const key_ref_t key_ref)
664cceb0
DH
120{
121 return (unsigned long) key_ref & 1UL;
122}
123
1da177e4
LT
124/*****************************************************************************/
125/*
126 * authentication token / access credential / keyring
127 * - types of key include:
128 * - keyrings
129 * - disk encryption IDs
130 * - Kerberos TGTs and tickets
131 */
132struct key {
133 atomic_t usage; /* number of references */
134 key_serial_t serial; /* key serial number */
65d87fe6
DH
135 union {
136 struct list_head graveyard_link;
137 struct rb_node serial_node;
138 };
1da177e4
LT
139 struct rw_semaphore sem; /* change vs change sem */
140 struct key_user *user; /* owner of this key */
29db9190 141 void *security; /* security data for this key */
5d135440
DH
142 union {
143 time_t expiry; /* time at which key expires (or 0) */
144 time_t revoked_at; /* time at which key was revoked */
145 };
31d5a79d 146 time_t last_used_at; /* last time used for LRU keyring discard */
9a56c2db
EB
147 kuid_t uid;
148 kgid_t gid;
1da177e4
LT
149 key_perm_t perm; /* access permissions */
150 unsigned short quotalen; /* length added to quota */
76d8aeab
DH
151 unsigned short datalen; /* payload data length
152 * - may not match RCU dereferenced payload
153 * - payload should contain own length
154 */
1da177e4
LT
155
156#ifdef KEY_DEBUGGING
157 unsigned magic;
158#define KEY_DEBUG_MAGIC 0x18273645u
159#define KEY_DEBUG_MAGIC_X 0xf8e9dacbu
160#endif
161
76d8aeab
DH
162 unsigned long flags; /* status flags (change with bitops) */
163#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */
164#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */
165#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */
166#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */
167#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */
168#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */
700920eb 169#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */
fd75815f 170#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */
76d8aeab 171
16feef43
DH
172 /* the key type and key description string
173 * - the desc is used to match a key against search criteria
174 * - it should be a printable string
1da177e4
LT
175 * - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
176 */
16feef43
DH
177 union {
178 struct keyring_index_key index_key;
179 struct {
180 struct key_type *type; /* type of key */
181 char *description;
182 };
183 };
1da177e4
LT
184
185 /* type specific data
186 * - this is used by the keyring type to index the name
187 */
188 union {
189 struct list_head link;
7318226e
DH
190 unsigned long x[2];
191 void *p[2];
fdd1b945 192 int reject_error;
1da177e4
LT
193 } type_data;
194
195 /* key data
196 * - this is used to hold the data actually used in cryptography or
197 * whatever
198 */
199 union {
b2a4df20
DH
200 union {
201 unsigned long value;
202 void __rcu *rcudata;
203 void *data;
ab3c3587 204 void *data2[2];
b2a4df20
DH
205 } payload;
206 struct assoc_array keys;
207 };
1da177e4
LT
208};
209
1da177e4
LT
210extern struct key *key_alloc(struct key_type *type,
211 const char *desc,
9a56c2db 212 kuid_t uid, kgid_t gid,
d84f4f99 213 const struct cred *cred,
7e047ef5
DH
214 key_perm_t perm,
215 unsigned long flags);
216
217
218#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
219#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
220#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
221
1da177e4 222extern void key_revoke(struct key *key);
fd75815f 223extern void key_invalidate(struct key *key);
1da177e4
LT
224extern void key_put(struct key *key);
225
ccc3e6d9 226static inline struct key *__key_get(struct key *key)
1da177e4 227{
ccc3e6d9 228 atomic_inc(&key->usage);
1da177e4
LT
229 return key;
230}
231
ccc3e6d9
DH
232static inline struct key *key_get(struct key *key)
233{
234 return key ? __key_get(key) : key;
235}
236
664cceb0
DH
237static inline void key_ref_put(key_ref_t key_ref)
238{
239 key_put(key_ref_to_ptr(key_ref));
240}
241
1da177e4
LT
242extern struct key *request_key(struct key_type *type,
243 const char *description,
244 const char *callout_info);
245
4e54f085
DH
246extern struct key *request_key_with_auxdata(struct key_type *type,
247 const char *description,
4a38e122
DH
248 const void *callout_info,
249 size_t callout_len,
4e54f085
DH
250 void *aux);
251
76181c13
DH
252extern struct key *request_key_async(struct key_type *type,
253 const char *description,
4a38e122
DH
254 const void *callout_info,
255 size_t callout_len);
76181c13
DH
256
257extern struct key *request_key_async_with_auxdata(struct key_type *type,
258 const char *description,
4a38e122
DH
259 const void *callout_info,
260 size_t callout_len,
76181c13
DH
261 void *aux);
262
263extern int wait_for_key_construction(struct key *key, bool intr);
264
b404aef7 265extern int key_validate(const struct key *key);
1da177e4 266
664cceb0
DH
267extern key_ref_t key_create_or_update(key_ref_t keyring,
268 const char *type,
269 const char *description,
270 const void *payload,
271 size_t plen,
6b79ccb5 272 key_perm_t perm,
7e047ef5 273 unsigned long flags);
1da177e4 274
664cceb0 275extern int key_update(key_ref_t key,
1da177e4
LT
276 const void *payload,
277 size_t plen);
278
279extern int key_link(struct key *keyring,
280 struct key *key);
281
282extern int key_unlink(struct key *keyring,
283 struct key *key);
284
9a56c2db 285extern struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
d84f4f99 286 const struct cred *cred,
96b5c8fe 287 key_perm_t perm,
7e047ef5 288 unsigned long flags,
d720024e 289 struct key *dest);
1da177e4
LT
290
291extern int keyring_clear(struct key *keyring);
292
664cceb0
DH
293extern key_ref_t keyring_search(key_ref_t keyring,
294 struct key_type *type,
295 const char *description);
1da177e4 296
1da177e4
LT
297extern int keyring_add_key(struct key *keyring,
298 struct key *key);
299
300extern struct key *key_lookup(key_serial_t id);
301
456a8167 302static inline key_serial_t key_serial(const struct key *key)
7249db2c
DH
303{
304 return key ? key->serial : 0;
305}
1da177e4 306
59e6b9c1
BS
307extern void key_set_timeout(struct key *, unsigned);
308
78b7280c
DH
309/**
310 * key_is_instantiated - Determine if a key has been positively instantiated
311 * @key: The key to check.
312 *
313 * Return true if the specified key has been positively instantiated, false
314 * otherwise.
315 */
316static inline bool key_is_instantiated(const struct key *key)
317{
318 return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
319 !test_bit(KEY_FLAG_NEGATIVE, &key->flags);
320}
321
633e804e
DH
322#define rcu_dereference_key(KEY) \
323 (rcu_dereference_protected((KEY)->payload.rcudata, \
324 rwsem_is_locked(&((struct key *)(KEY))->sem)))
325
ee0b31a2 326#define rcu_assign_keypointer(KEY, PAYLOAD) \
e5c1f444
PM
327do { \
328 rcu_assign_pointer((KEY)->payload.rcudata, (PAYLOAD)); \
329} while (0)
ee0b31a2 330
0b77f5bf
DH
331#ifdef CONFIG_SYSCTL
332extern ctl_table key_sysctls[];
333#endif
1da177e4
LT
334/*
335 * the userspace interface
336 */
d84f4f99 337extern int install_thread_keyring_to_cred(struct cred *cred);
1da177e4
LT
338extern void key_fsuid_changed(struct task_struct *tsk);
339extern void key_fsgid_changed(struct task_struct *tsk);
340extern void key_init(void);
341
342#else /* CONFIG_KEYS */
343
344#define key_validate(k) 0
345#define key_serial(k) 0
7888e7ff 346#define key_get(k) ({ NULL; })
0dab9cfa 347#define key_revoke(k) do { } while(0)
fd75815f 348#define key_invalidate(k) do { } while(0)
1da177e4 349#define key_put(k) do { } while(0)
664cceb0 350#define key_ref_put(k) do { } while(0)
8bbf4976
DH
351#define make_key_ref(k, p) NULL
352#define key_ref_to_ptr(k) NULL
664cceb0 353#define is_key_possessed(k) 0
1da177e4
LT
354#define key_fsuid_changed(t) do { } while(0)
355#define key_fsgid_changed(t) do { } while(0)
356#define key_init() do { } while(0)
357
358#endif /* CONFIG_KEYS */
359#endif /* __KERNEL__ */
360#endif /* _LINUX_KEY_H */