Merge tag 'v3.10.108' into update
[GitHub/mt8127/android_kernel_alcatel_ttab.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>
1da177e4
LT
25
26#ifdef __KERNEL__
9a56c2db 27#include <linux/uidgid.h>
1da177e4
LT
28
29/* key handle serial number */
30typedef int32_t key_serial_t;
31
32/* key handle permissions mask */
33typedef uint32_t key_perm_t;
34
35struct key;
36
37#ifdef CONFIG_KEYS
38
39#undef KEY_DEBUGGING
40
664cceb0
DH
41#define KEY_POS_VIEW 0x01000000 /* possessor can view a key's attributes */
42#define KEY_POS_READ 0x02000000 /* possessor can read key payload / view keyring */
43#define KEY_POS_WRITE 0x04000000 /* possessor can update key payload / add link to keyring */
44#define KEY_POS_SEARCH 0x08000000 /* possessor can find a key in search / search a keyring */
45#define KEY_POS_LINK 0x10000000 /* possessor can create a link to a key/keyring */
29db9190
DH
46#define KEY_POS_SETATTR 0x20000000 /* possessor can set key attributes */
47#define KEY_POS_ALL 0x3f000000
664cceb0
DH
48
49#define KEY_USR_VIEW 0x00010000 /* user permissions... */
50#define KEY_USR_READ 0x00020000
51#define KEY_USR_WRITE 0x00040000
52#define KEY_USR_SEARCH 0x00080000
53#define KEY_USR_LINK 0x00100000
29db9190
DH
54#define KEY_USR_SETATTR 0x00200000
55#define KEY_USR_ALL 0x003f0000
1da177e4
LT
56
57#define KEY_GRP_VIEW 0x00000100 /* group permissions... */
58#define KEY_GRP_READ 0x00000200
59#define KEY_GRP_WRITE 0x00000400
60#define KEY_GRP_SEARCH 0x00000800
61#define KEY_GRP_LINK 0x00001000
29db9190
DH
62#define KEY_GRP_SETATTR 0x00002000
63#define KEY_GRP_ALL 0x00003f00
1da177e4
LT
64
65#define KEY_OTH_VIEW 0x00000001 /* third party permissions... */
66#define KEY_OTH_READ 0x00000002
67#define KEY_OTH_WRITE 0x00000004
68#define KEY_OTH_SEARCH 0x00000008
69#define KEY_OTH_LINK 0x00000010
29db9190
DH
70#define KEY_OTH_SETATTR 0x00000020
71#define KEY_OTH_ALL 0x0000003f
1da177e4 72
6b79ccb5
AR
73#define KEY_PERM_UNDEF 0xffffffff
74
1da177e4
LT
75struct seq_file;
76struct user_struct;
77struct signal_struct;
d84f4f99 78struct cred;
1da177e4
LT
79
80struct key_type;
81struct key_owner;
82struct keyring_list;
83struct keyring_name;
84
664cceb0
DH
85/*****************************************************************************/
86/*
87 * key reference with possession attribute handling
88 *
89 * NOTE! key_ref_t is a typedef'd pointer to a type that is not actually
90 * defined. This is because we abuse the bottom bit of the reference to carry a
91 * flag to indicate whether the calling process possesses that key in one of
92 * its keyrings.
93 *
94 * the key_ref_t has been made a separate type so that the compiler can reject
95 * attempts to dereference it without proper conversion.
96 *
97 * the three functions are used to assemble and disassemble references
98 */
99typedef struct __key_reference_with_attributes *key_ref_t;
100
101static inline key_ref_t make_key_ref(const struct key *key,
102 unsigned long possession)
103{
104 return (key_ref_t) ((unsigned long) key | possession);
105}
106
107static inline struct key *key_ref_to_ptr(const key_ref_t key_ref)
108{
109 return (struct key *) ((unsigned long) key_ref & ~1UL);
110}
111
112static inline unsigned long is_key_possessed(const key_ref_t key_ref)
113{
114 return (unsigned long) key_ref & 1UL;
115}
116
1da177e4
LT
117/*****************************************************************************/
118/*
119 * authentication token / access credential / keyring
120 * - types of key include:
121 * - keyrings
122 * - disk encryption IDs
123 * - Kerberos TGTs and tickets
124 */
125struct key {
126 atomic_t usage; /* number of references */
127 key_serial_t serial; /* key serial number */
65d87fe6
DH
128 union {
129 struct list_head graveyard_link;
130 struct rb_node serial_node;
131 };
1da177e4 132 struct key_type *type; /* type of key */
1da177e4
LT
133 struct rw_semaphore sem; /* change vs change sem */
134 struct key_user *user; /* owner of this key */
29db9190 135 void *security; /* security data for this key */
5d135440
DH
136 union {
137 time_t expiry; /* time at which key expires (or 0) */
138 time_t revoked_at; /* time at which key was revoked */
139 };
31d5a79d 140 time_t last_used_at; /* last time used for LRU keyring discard */
9a56c2db
EB
141 kuid_t uid;
142 kgid_t gid;
1da177e4
LT
143 key_perm_t perm; /* access permissions */
144 unsigned short quotalen; /* length added to quota */
76d8aeab
DH
145 unsigned short datalen; /* payload data length
146 * - may not match RCU dereferenced payload
147 * - payload should contain own length
148 */
1da177e4
LT
149
150#ifdef KEY_DEBUGGING
151 unsigned magic;
152#define KEY_DEBUG_MAGIC 0x18273645u
153#define KEY_DEBUG_MAGIC_X 0xf8e9dacbu
154#endif
155
76d8aeab
DH
156 unsigned long flags; /* status flags (change with bitops) */
157#define KEY_FLAG_INSTANTIATED 0 /* set if key has been instantiated */
158#define KEY_FLAG_DEAD 1 /* set if key type has been deleted */
159#define KEY_FLAG_REVOKED 2 /* set if key had been revoked */
160#define KEY_FLAG_IN_QUOTA 3 /* set if key consumes quota */
161#define KEY_FLAG_USER_CONSTRUCT 4 /* set if key is being constructed in userspace */
162#define KEY_FLAG_NEGATIVE 5 /* set if key is negative */
700920eb 163#define KEY_FLAG_ROOT_CAN_CLEAR 6 /* set if key can be cleared by root without permission */
fd75815f 164#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */
e8705c42 165#define KEY_FLAG_UID_KEYRING 11 /* set if key is a user or user session keyring */
76d8aeab 166
1da177e4
LT
167 /* the description string
168 * - this is used to match a key against search criteria
169 * - this should be a printable string
170 * - eg: for krb5 AFS, this might be "afs@REDHAT.COM"
171 */
172 char *description;
173
174 /* type specific data
175 * - this is used by the keyring type to index the name
176 */
177 union {
178 struct list_head link;
7318226e
DH
179 unsigned long x[2];
180 void *p[2];
fdd1b945 181 int reject_error;
1da177e4
LT
182 } type_data;
183
184 /* key data
185 * - this is used to hold the data actually used in cryptography or
186 * whatever
187 */
188 union {
189 unsigned long value;
e63ba744 190 void __rcu *rcudata;
1da177e4 191 void *data;
e63ba744 192 struct keyring_list __rcu *subscriptions;
1da177e4
LT
193 } payload;
194};
195
1da177e4
LT
196extern struct key *key_alloc(struct key_type *type,
197 const char *desc,
9a56c2db 198 kuid_t uid, kgid_t gid,
d84f4f99 199 const struct cred *cred,
7e047ef5
DH
200 key_perm_t perm,
201 unsigned long flags);
202
203
204#define KEY_ALLOC_IN_QUOTA 0x0000 /* add to quota, reject if would overrun */
205#define KEY_ALLOC_QUOTA_OVERRUN 0x0001 /* add to quota, permit even if overrun */
206#define KEY_ALLOC_NOT_IN_QUOTA 0x0002 /* not in quota */
e8705c42 207#define KEY_ALLOC_UID_KEYRING 0x0010 /* allocating a user or user session keyring */
7e047ef5 208
1da177e4 209extern void key_revoke(struct key *key);
fd75815f 210extern void key_invalidate(struct key *key);
1da177e4
LT
211extern void key_put(struct key *key);
212
213static inline struct key *key_get(struct key *key)
214{
215 if (key)
216 atomic_inc(&key->usage);
217 return key;
218}
219
664cceb0
DH
220static inline void key_ref_put(key_ref_t key_ref)
221{
222 key_put(key_ref_to_ptr(key_ref));
223}
224
1da177e4
LT
225extern struct key *request_key(struct key_type *type,
226 const char *description,
227 const char *callout_info);
228
4e54f085
DH
229extern struct key *request_key_with_auxdata(struct key_type *type,
230 const char *description,
4a38e122
DH
231 const void *callout_info,
232 size_t callout_len,
4e54f085
DH
233 void *aux);
234
76181c13
DH
235extern struct key *request_key_async(struct key_type *type,
236 const char *description,
4a38e122
DH
237 const void *callout_info,
238 size_t callout_len);
76181c13
DH
239
240extern struct key *request_key_async_with_auxdata(struct key_type *type,
241 const char *description,
4a38e122
DH
242 const void *callout_info,
243 size_t callout_len,
76181c13
DH
244 void *aux);
245
246extern int wait_for_key_construction(struct key *key, bool intr);
247
b404aef7 248extern int key_validate(const struct key *key);
1da177e4 249
664cceb0
DH
250extern key_ref_t key_create_or_update(key_ref_t keyring,
251 const char *type,
252 const char *description,
253 const void *payload,
254 size_t plen,
6b79ccb5 255 key_perm_t perm,
7e047ef5 256 unsigned long flags);
1da177e4 257
664cceb0 258extern int key_update(key_ref_t key,
1da177e4
LT
259 const void *payload,
260 size_t plen);
261
262extern int key_link(struct key *keyring,
263 struct key *key);
264
265extern int key_unlink(struct key *keyring,
266 struct key *key);
267
9a56c2db 268extern struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
d84f4f99 269 const struct cred *cred,
96b5c8fe 270 key_perm_t perm,
7e047ef5 271 unsigned long flags,
d720024e 272 struct key *dest);
1da177e4
LT
273
274extern int keyring_clear(struct key *keyring);
275
664cceb0
DH
276extern key_ref_t keyring_search(key_ref_t keyring,
277 struct key_type *type,
278 const char *description);
1da177e4 279
1da177e4
LT
280extern int keyring_add_key(struct key *keyring,
281 struct key *key);
282
283extern struct key *key_lookup(key_serial_t id);
284
456a8167 285static inline key_serial_t key_serial(const struct key *key)
7249db2c
DH
286{
287 return key ? key->serial : 0;
288}
1da177e4 289
59e6b9c1
BS
290extern void key_set_timeout(struct key *, unsigned);
291
78b7280c
DH
292/**
293 * key_is_instantiated - Determine if a key has been positively instantiated
294 * @key: The key to check.
295 *
296 * Return true if the specified key has been positively instantiated, false
297 * otherwise.
298 */
299static inline bool key_is_instantiated(const struct key *key)
300{
301 return test_bit(KEY_FLAG_INSTANTIATED, &key->flags) &&
302 !test_bit(KEY_FLAG_NEGATIVE, &key->flags);
303}
304
633e804e
DH
305#define rcu_dereference_key(KEY) \
306 (rcu_dereference_protected((KEY)->payload.rcudata, \
307 rwsem_is_locked(&((struct key *)(KEY))->sem)))
308
ee0b31a2 309#define rcu_assign_keypointer(KEY, PAYLOAD) \
e5c1f444
PM
310do { \
311 rcu_assign_pointer((KEY)->payload.rcudata, (PAYLOAD)); \
312} while (0)
ee0b31a2 313
0b77f5bf
DH
314#ifdef CONFIG_SYSCTL
315extern ctl_table key_sysctls[];
316#endif
1da177e4
LT
317/*
318 * the userspace interface
319 */
d84f4f99 320extern int install_thread_keyring_to_cred(struct cred *cred);
1da177e4
LT
321extern void key_fsuid_changed(struct task_struct *tsk);
322extern void key_fsgid_changed(struct task_struct *tsk);
323extern void key_init(void);
324
325#else /* CONFIG_KEYS */
326
327#define key_validate(k) 0
328#define key_serial(k) 0
7888e7ff 329#define key_get(k) ({ NULL; })
0dab9cfa 330#define key_revoke(k) do { } while(0)
fd75815f 331#define key_invalidate(k) do { } while(0)
1da177e4 332#define key_put(k) do { } while(0)
664cceb0 333#define key_ref_put(k) do { } while(0)
8bbf4976
DH
334#define make_key_ref(k, p) NULL
335#define key_ref_to_ptr(k) NULL
664cceb0 336#define is_key_possessed(k) 0
1da177e4
LT
337#define key_fsuid_changed(t) do { } while(0)
338#define key_fsgid_changed(t) do { } while(0)
339#define key_init() do { } while(0)
340
341#endif /* CONFIG_KEYS */
342#endif /* __KERNEL__ */
343#endif /* _LINUX_KEY_H */