aboutsummaryrefslogtreecommitdiff
path: root/security/keys/internal.h
blob: 56a133d8f37d192ffb1adbc45cad9610f5cbbc5b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
/* internal.h: authentication token and access key management internal defs
 *
 * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#ifndef _INTERNAL_H
#define _INTERNAL_H

#include <linux/sched.h>
#include <linux/key-type.h>

#ifdef __KDEBUG
#define kenter(FMT, ...) \
	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) \
	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
#else
#define kenter(FMT, ...) \
	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) \
	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) \
	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
#endif

extern struct key_type key_type_user;

/*****************************************************************************/
/*
 * keep track of keys for a user
 * - this needs to be separate to user_struct to avoid a refcount-loop
 *   (user_struct pins some keyrings which pin this struct)
 * - this also keeps track of keys under request from userspace for this UID
 */
struct key_user {
	struct rb_node		node;
	struct mutex		cons_lock;	/* construction initiation lock */
	spinlock_t		lock;
	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
	atomic_t		nkeys;		/* number of keys */
	atomic_t		nikeys;		/* number of instantiated keys */
	uid_t			uid;
	struct user_namespace	*user_ns;
	int			qnkeys;		/* number of keys allocated to this user */
	int			qnbytes;	/* number of bytes allocated to this user */
};

extern struct rb_root	key_user_tree;
extern spinlock_t	key_user_lock;
extern struct key_user	root_key_user;

extern struct key_user *key_user_lookup(uid_t uid,
					struct user_namespace *user_ns);
extern void key_user_put(struct key_user *user);

/*
 * key quota limits
 * - root has its own separate limits to everyone else
 */
extern unsigned key_quota_root_maxkeys;
extern unsigned key_quota_root_maxbytes;
extern unsigned key_quota_maxkeys;
extern unsigned key_quota_maxbytes;

#define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */


extern struct rb_root key_serial_tree;
extern spinlock_t key_serial_lock;
extern struct mutex key_construction_mutex;
extern wait_queue_head_t request_key_conswq;


extern struct key_type *key_type_lookup(const char *type);
extern void key_type_put(struct key_type *ktype);

extern int __key_link_begin(struct key *keyring,
			    const struct key_type *type,
			    const char *description,
			    struct keyring_list **_prealloc);
extern int __key_link_check_live_key(struct key *keyring, struct key *key);
extern void __key_link(struct key *keyring, struct key *key,
		       struct keyring_list **_prealloc);
extern void __key_link_end(struct key *keyring,
			   struct key_type *type,
			   struct keyring_list *prealloc);

extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
				      const struct key_type *type,
				      const char *description,
				      key_perm_t perm);

extern struct key *keyring_search_instkey(struct key *keyring,
					  key_serial_t target_id);

typedef int (*key_match_func_t)(const struct key *, const void *);

extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
				    const struct cred *cred,
				    struct key_type *type,
				    const void *description,
				    key_match_func_t match);

extern key_ref_t search_my_process_keyrings(struct key_type *type,
					    const void *description,
					    key_match_func_t match,
					    const struct cred *cred);
extern key_ref_t search_process_keyrings(struct key_type *type,
					 const void *description,
					 key_match_func_t match,
					 const struct cred *cred);

extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);

extern int install_user_keyrings(void);
extern int install_thread_keyring_to_cred(struct cred *);
extern int install_process_keyring_to_cred(struct cred *);
extern int install_session_keyring_to_cred(struct cred *, struct key *);

extern struct key *request_key_and_link(struct key_type *type,
					const char *description,
					const void *callout_info,
					size_t callout_len,
					void *aux,
					struct key *dest_keyring,
					unsigned long flags);

extern int lookup_user_key_possessed(const struct key *key, const void *target);
extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
				 key_perm_t perm);
#define KEY_LOOKUP_CREATE	0x01
#define KEY_LOOKUP_PARTIAL	0x02
#define KEY_LOOKUP_FOR_UNLINK	0x04

extern long join_session_keyring(const char *name);

extern unsigned key_gc_delay;
extern void keyring_gc(struct key *keyring, time_t limit);
extern void key_schedule_gc(time_t expiry_at);

/*
 * check to see whether permission is granted to use a key in the desired way
 */
extern int key_task_permission(const key_ref_t key_ref,
			       const struct cred *cred,
			       key_perm_t perm);

static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
{
	return key_task_permission(key_ref, current_cred(), perm);
}

/* required permissions */
#define	KEY_VIEW	0x01	/* require permission to view attributes */
#define	KEY_READ	0x02	/* require permission to read content */
#define	KEY_WRITE	0x04	/* require permission to update / modify */
#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
#define	KEY_LINK	0x10	/* require permission to link */
#define	KEY_SETATTR	0x20	/* require permission to change attributes */
#define	KEY_ALL		0x3f	/* all the above permissions */

/*
 * request_key authorisation
 */
struct request_key_auth {
	struct key		*target_key;
	struct key		*dest_keyring;
	const struct cred	*cred;
	void			*callout_info;
	size_t			callout_len;
	pid_t			pid;
};

extern struct key_type key_type_request_key_auth;
extern struct key *request_key_auth_new(struct key *target,
					const void *callout_info,
					size_t callout_len,
					struct key *dest_keyring);

extern struct key *key_get_instantiation_authkey(key_serial_t target_id);

/*
 * keyctl functions
 */
extern long keyctl_get_keyring_ID(key_serial_t, int);
extern long keyctl_join_session_keyring(const char __user *);
extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
extern long keyctl_revoke_key(key_serial_t);
extern long keyctl_keyring_clear(key_serial_t);
extern long keyctl_keyring_link(key_serial_t, key_serial_t);
extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
extern long keyctl_keyring_search(key_serial_t, const char __user *,
				  const char __user *, key_serial_t);
extern long keyctl_read_key(key_serial_t, char __user *, size_t);
extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
extern long keyctl_setperm_key(key_serial_t, key_perm_t);
extern long keyctl_instantiate_key(key_serial_t, const void __user *,
				   size_t, key_serial_t);
extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
extern long keyctl_set_reqkey_keyring(int);
extern long keyctl_set_timeout(key_serial_t, unsigned);
extern long keyctl_assume_authority(key_serial_t);
extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
				size_t buflen);
extern long keyctl_session_to_parent(void);

/*
 * debugging key validation
 */
#ifdef KEY_DEBUGGING
extern void __key_check(const struct key *);

static inline void key_check(const struct key *key)
{
	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
		__key_check(key);
}

#else

#define key_check(key) do {} while(0)

#endif

#endif /* _INTERNAL_H */