xref: /openbmc/linux/security/keys/internal.h (revision 609e478b)
1 /* Authentication token and access key management internal defs
2  *
3  * Copyright (C) 2003-5, 2007 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 _INTERNAL_H
13 #define _INTERNAL_H
14 
15 #include <linux/sched.h>
16 #include <linux/key-type.h>
17 #include <linux/task_work.h>
18 
19 struct iovec;
20 
21 #ifdef __KDEBUG
22 #define kenter(FMT, ...) \
23 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
24 #define kleave(FMT, ...) \
25 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
26 #define kdebug(FMT, ...) \
27 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
28 #else
29 #define kenter(FMT, ...) \
30 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
31 #define kleave(FMT, ...) \
32 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
33 #define kdebug(FMT, ...) \
34 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
35 #endif
36 
37 extern struct key_type key_type_dead;
38 extern struct key_type key_type_user;
39 extern struct key_type key_type_logon;
40 
41 /*****************************************************************************/
42 /*
43  * Keep track of keys for a user.
44  *
45  * This needs to be separate to user_struct to avoid a refcount-loop
46  * (user_struct pins some keyrings which pin this struct).
47  *
48  * We also keep track of keys under request from userspace for this UID here.
49  */
50 struct key_user {
51 	struct rb_node		node;
52 	struct mutex		cons_lock;	/* construction initiation lock */
53 	spinlock_t		lock;
54 	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
55 	atomic_t		nkeys;		/* number of keys */
56 	atomic_t		nikeys;		/* number of instantiated keys */
57 	kuid_t			uid;
58 	int			qnkeys;		/* number of keys allocated to this user */
59 	int			qnbytes;	/* number of bytes allocated to this user */
60 };
61 
62 extern struct rb_root	key_user_tree;
63 extern spinlock_t	key_user_lock;
64 extern struct key_user	root_key_user;
65 
66 extern struct key_user *key_user_lookup(kuid_t uid);
67 extern void key_user_put(struct key_user *user);
68 
69 /*
70  * Key quota limits.
71  * - root has its own separate limits to everyone else
72  */
73 extern unsigned key_quota_root_maxkeys;
74 extern unsigned key_quota_root_maxbytes;
75 extern unsigned key_quota_maxkeys;
76 extern unsigned key_quota_maxbytes;
77 
78 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
79 
80 
81 extern struct kmem_cache *key_jar;
82 extern struct rb_root key_serial_tree;
83 extern spinlock_t key_serial_lock;
84 extern struct mutex key_construction_mutex;
85 extern wait_queue_head_t request_key_conswq;
86 
87 
88 extern struct key_type *key_type_lookup(const char *type);
89 extern void key_type_put(struct key_type *ktype);
90 
91 extern int __key_link_begin(struct key *keyring,
92 			    const struct keyring_index_key *index_key,
93 			    struct assoc_array_edit **_edit);
94 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
95 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
96 extern void __key_link_end(struct key *keyring,
97 			   const struct keyring_index_key *index_key,
98 			   struct assoc_array_edit *edit);
99 
100 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
101 				    const struct keyring_index_key *index_key);
102 
103 extern struct key *keyring_search_instkey(struct key *keyring,
104 					  key_serial_t target_id);
105 
106 extern int iterate_over_keyring(const struct key *keyring,
107 				int (*func)(const struct key *key, void *data),
108 				void *data);
109 
110 struct keyring_search_context {
111 	struct keyring_index_key index_key;
112 	const struct cred	*cred;
113 	struct key_match_data	match_data;
114 	unsigned		flags;
115 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
116 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
117 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
118 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
119 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
120 
121 	int (*iterator)(const void *object, void *iterator_data);
122 
123 	/* Internal stuff */
124 	int			skipped_ret;
125 	bool			possessed;
126 	key_ref_t		result;
127 	struct timespec		now;
128 };
129 
130 extern bool key_default_cmp(const struct key *key,
131 			    const struct key_match_data *match_data);
132 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
133 				    struct keyring_search_context *ctx);
134 
135 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
136 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
137 
138 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
139 
140 extern int install_user_keyrings(void);
141 extern int install_thread_keyring_to_cred(struct cred *);
142 extern int install_process_keyring_to_cred(struct cred *);
143 extern int install_session_keyring_to_cred(struct cred *, struct key *);
144 
145 extern struct key *request_key_and_link(struct key_type *type,
146 					const char *description,
147 					const void *callout_info,
148 					size_t callout_len,
149 					void *aux,
150 					struct key *dest_keyring,
151 					unsigned long flags);
152 
153 extern bool lookup_user_key_possessed(const struct key *key,
154 				      const struct key_match_data *match_data);
155 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
156 				 key_perm_t perm);
157 #define KEY_LOOKUP_CREATE	0x01
158 #define KEY_LOOKUP_PARTIAL	0x02
159 #define KEY_LOOKUP_FOR_UNLINK	0x04
160 
161 extern long join_session_keyring(const char *name);
162 extern void key_change_session_keyring(struct callback_head *twork);
163 
164 extern struct work_struct key_gc_work;
165 extern unsigned key_gc_delay;
166 extern void keyring_gc(struct key *keyring, time_t limit);
167 extern void key_schedule_gc(time_t gc_at);
168 extern void key_schedule_gc_links(void);
169 extern void key_gc_keytype(struct key_type *ktype);
170 
171 extern int key_task_permission(const key_ref_t key_ref,
172 			       const struct cred *cred,
173 			       key_perm_t perm);
174 
175 /*
176  * Check to see whether permission is granted to use a key in the desired way.
177  */
178 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
179 {
180 	return key_task_permission(key_ref, current_cred(), perm);
181 }
182 
183 /*
184  * Authorisation record for request_key().
185  */
186 struct request_key_auth {
187 	struct key		*target_key;
188 	struct key		*dest_keyring;
189 	const struct cred	*cred;
190 	void			*callout_info;
191 	size_t			callout_len;
192 	pid_t			pid;
193 };
194 
195 extern struct key_type key_type_request_key_auth;
196 extern struct key *request_key_auth_new(struct key *target,
197 					const void *callout_info,
198 					size_t callout_len,
199 					struct key *dest_keyring);
200 
201 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
202 
203 /*
204  * Determine whether a key is dead.
205  */
206 static inline bool key_is_dead(const struct key *key, time_t limit)
207 {
208 	return
209 		key->flags & ((1 << KEY_FLAG_DEAD) |
210 			      (1 << KEY_FLAG_INVALIDATED)) ||
211 		(key->expiry > 0 && key->expiry <= limit);
212 }
213 
214 /*
215  * keyctl() functions
216  */
217 extern long keyctl_get_keyring_ID(key_serial_t, int);
218 extern long keyctl_join_session_keyring(const char __user *);
219 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
220 extern long keyctl_revoke_key(key_serial_t);
221 extern long keyctl_keyring_clear(key_serial_t);
222 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
223 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
224 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
225 extern long keyctl_keyring_search(key_serial_t, const char __user *,
226 				  const char __user *, key_serial_t);
227 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
228 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
229 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
230 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
231 				   size_t, key_serial_t);
232 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
233 extern long keyctl_set_reqkey_keyring(int);
234 extern long keyctl_set_timeout(key_serial_t, unsigned);
235 extern long keyctl_assume_authority(key_serial_t);
236 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
237 				size_t buflen);
238 extern long keyctl_session_to_parent(void);
239 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
240 extern long keyctl_instantiate_key_iov(key_serial_t,
241 				       const struct iovec __user *,
242 				       unsigned, key_serial_t);
243 extern long keyctl_invalidate_key(key_serial_t);
244 
245 extern long keyctl_instantiate_key_common(key_serial_t,
246 					  const struct iovec *,
247 					  unsigned, size_t, key_serial_t);
248 #ifdef CONFIG_PERSISTENT_KEYRINGS
249 extern long keyctl_get_persistent(uid_t, key_serial_t);
250 extern unsigned persistent_keyring_expiry;
251 #else
252 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
253 {
254 	return -EOPNOTSUPP;
255 }
256 #endif
257 
258 /*
259  * Debugging key validation
260  */
261 #ifdef KEY_DEBUGGING
262 extern void __key_check(const struct key *);
263 
264 static inline void key_check(const struct key *key)
265 {
266 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
267 		__key_check(key);
268 }
269 
270 #else
271 
272 #define key_check(key) do {} while(0)
273 
274 #endif
275 
276 #endif /* _INTERNAL_H */
277