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1/* key-ui.h: key userspace interface stuff
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#ifndef _LINUX_KEY_UI_H
13#define _LINUX_KEY_UI_H
14
15#include <linux/key.h>
16
17/* the key tree */
18extern struct rb_root key_serial_tree;
19extern spinlock_t key_serial_lock;
20
21/* required permissions */
22#define KEY_VIEW 0x01 /* require permission to view attributes */
23#define KEY_READ 0x02 /* require permission to read content */
24#define KEY_WRITE 0x04 /* require permission to update / modify */
25#define KEY_SEARCH 0x08 /* require permission to search (keyring) or find (key) */
26#define KEY_LINK 0x10 /* require permission to link */
27#define KEY_ALL 0x1f /* all the above permissions */
28
29/*
30 * the keyring payload contains a list of the keys to which the keyring is
31 * subscribed
32 */
33struct keyring_list {
34 struct rcu_head rcu; /* RCU deletion hook */
35 unsigned short maxkeys; /* max keys this list can hold */
36 unsigned short nkeys; /* number of keys currently held */
37 unsigned short delkey; /* key to be unlinked by RCU */
38 struct key *keys[0];
39};
40
41
42/*
43 * check to see whether permission is granted to use a key in the desired way
44 */
45static inline int key_permission(const struct key *key, key_perm_t perm)
46{
47 key_perm_t kperm;
48
49 if (key->uid == current->fsuid)
50 kperm = key->perm >> 16;
51 else if (key->gid != -1 &&
52 key->perm & KEY_GRP_ALL &&
53 in_group_p(key->gid)
54 )
55 kperm = key->perm >> 8;
56 else
57 kperm = key->perm;
58
59 kperm = kperm & perm & KEY_ALL;
60
61 return kperm == perm;
62}
63
64/*
65 * check to see whether permission is granted to use a key in at least one of
66 * the desired ways
67 */
68static inline int key_any_permission(const struct key *key, key_perm_t perm)
69{
70 key_perm_t kperm;
71
72 if (key->uid == current->fsuid)
73 kperm = key->perm >> 16;
74 else if (key->gid != -1 &&
75 key->perm & KEY_GRP_ALL &&
76 in_group_p(key->gid)
77 )
78 kperm = key->perm >> 8;
79 else
80 kperm = key->perm;
81
82 kperm = kperm & perm & KEY_ALL;
83
84 return kperm != 0;
85}
86
87static inline int key_task_groups_search(struct task_struct *tsk, gid_t gid)
88{
89 int ret;
90
91 task_lock(tsk);
92 ret = groups_search(tsk->group_info, gid);
93 task_unlock(tsk);
94 return ret;
95}
96
97static inline int key_task_permission(const struct key *key,
98 struct task_struct *context,
99 key_perm_t perm)
100{
101 key_perm_t kperm;
102
103 if (key->uid == context->fsuid) {
104 kperm = key->perm >> 16;
105 }
106 else if (key->gid != -1 &&
107 key->perm & KEY_GRP_ALL && (
108 key->gid == context->fsgid ||
109 key_task_groups_search(context, key->gid)
110 )
111 ) {
112 kperm = key->perm >> 8;
113 }
114 else {
115 kperm = key->perm;
116 }
117
118 kperm = kperm & perm & KEY_ALL;
119
120 return kperm == perm;
121
122}
123
124extern struct key *lookup_user_key(struct task_struct *context,
125 key_serial_t id, int create, int partial,
126 key_perm_t perm);
127
128extern long join_session_keyring(const char *name);
129
130extern struct key_type *key_type_lookup(const char *type);
131extern void key_type_put(struct key_type *ktype);
132
133#define key_negative_timeout 60 /* default timeout on a negative key's existence */
134
135
136#endif /* _LINUX_KEY_UI_H */