xref: /openbmc/linux/security/keys/internal.h (revision 726bd223)
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/cred.h>
17 #include <linux/key-type.h>
18 #include <linux/task_work.h>
19 #include <linux/keyctl.h>
20 
21 struct iovec;
22 
23 #ifdef __KDEBUG
24 #define kenter(FMT, ...) \
25 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
26 #define kleave(FMT, ...) \
27 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
28 #define kdebug(FMT, ...) \
29 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
30 #else
31 #define kenter(FMT, ...) \
32 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
33 #define kleave(FMT, ...) \
34 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
35 #define kdebug(FMT, ...) \
36 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
37 #endif
38 
39 extern struct key_type key_type_dead;
40 extern struct key_type key_type_user;
41 extern struct key_type key_type_logon;
42 
43 /*****************************************************************************/
44 /*
45  * Keep track of keys for a user.
46  *
47  * This needs to be separate to user_struct to avoid a refcount-loop
48  * (user_struct pins some keyrings which pin this struct).
49  *
50  * We also keep track of keys under request from userspace for this UID here.
51  */
52 struct key_user {
53 	struct rb_node		node;
54 	struct mutex		cons_lock;	/* construction initiation lock */
55 	spinlock_t		lock;
56 	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
57 	atomic_t		nkeys;		/* number of keys */
58 	atomic_t		nikeys;		/* number of instantiated keys */
59 	kuid_t			uid;
60 	int			qnkeys;		/* number of keys allocated to this user */
61 	int			qnbytes;	/* number of bytes allocated to this user */
62 };
63 
64 extern struct rb_root	key_user_tree;
65 extern spinlock_t	key_user_lock;
66 extern struct key_user	root_key_user;
67 
68 extern struct key_user *key_user_lookup(kuid_t uid);
69 extern void key_user_put(struct key_user *user);
70 
71 /*
72  * Key quota limits.
73  * - root has its own separate limits to everyone else
74  */
75 extern unsigned key_quota_root_maxkeys;
76 extern unsigned key_quota_root_maxbytes;
77 extern unsigned key_quota_maxkeys;
78 extern unsigned key_quota_maxbytes;
79 
80 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
81 
82 
83 extern struct kmem_cache *key_jar;
84 extern struct rb_root key_serial_tree;
85 extern spinlock_t key_serial_lock;
86 extern struct mutex key_construction_mutex;
87 extern wait_queue_head_t request_key_conswq;
88 
89 
90 extern struct key_type *key_type_lookup(const char *type);
91 extern void key_type_put(struct key_type *ktype);
92 
93 extern int __key_link_begin(struct key *keyring,
94 			    const struct keyring_index_key *index_key,
95 			    struct assoc_array_edit **_edit);
96 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
97 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
98 extern void __key_link_end(struct key *keyring,
99 			   const struct keyring_index_key *index_key,
100 			   struct assoc_array_edit *edit);
101 
102 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
103 				    const struct keyring_index_key *index_key);
104 
105 extern struct key *keyring_search_instkey(struct key *keyring,
106 					  key_serial_t target_id);
107 
108 extern int iterate_over_keyring(const struct key *keyring,
109 				int (*func)(const struct key *key, void *data),
110 				void *data);
111 
112 struct keyring_search_context {
113 	struct keyring_index_key index_key;
114 	const struct cred	*cred;
115 	struct key_match_data	match_data;
116 	unsigned		flags;
117 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
118 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
119 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
120 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
121 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
122 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
123 
124 	int (*iterator)(const void *object, void *iterator_data);
125 
126 	/* Internal stuff */
127 	int			skipped_ret;
128 	bool			possessed;
129 	key_ref_t		result;
130 	struct timespec		now;
131 };
132 
133 extern bool key_default_cmp(const struct key *key,
134 			    const struct key_match_data *match_data);
135 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
136 				    struct keyring_search_context *ctx);
137 
138 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
139 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
140 
141 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
142 
143 extern int install_user_keyrings(void);
144 extern int install_thread_keyring_to_cred(struct cred *);
145 extern int install_process_keyring_to_cred(struct cred *);
146 extern int install_session_keyring_to_cred(struct cred *, struct key *);
147 
148 extern struct key *request_key_and_link(struct key_type *type,
149 					const char *description,
150 					const void *callout_info,
151 					size_t callout_len,
152 					void *aux,
153 					struct key *dest_keyring,
154 					unsigned long flags);
155 
156 extern bool lookup_user_key_possessed(const struct key *key,
157 				      const struct key_match_data *match_data);
158 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
159 				 key_perm_t perm);
160 #define KEY_LOOKUP_CREATE	0x01
161 #define KEY_LOOKUP_PARTIAL	0x02
162 #define KEY_LOOKUP_FOR_UNLINK	0x04
163 
164 extern long join_session_keyring(const char *name);
165 extern void key_change_session_keyring(struct callback_head *twork);
166 
167 extern struct work_struct key_gc_work;
168 extern unsigned key_gc_delay;
169 extern void keyring_gc(struct key *keyring, time_t limit);
170 extern void key_schedule_gc(time_t gc_at);
171 extern void key_schedule_gc_links(void);
172 extern void key_gc_keytype(struct key_type *ktype);
173 
174 extern int key_task_permission(const key_ref_t key_ref,
175 			       const struct cred *cred,
176 			       key_perm_t perm);
177 
178 /*
179  * Check to see whether permission is granted to use a key in the desired way.
180  */
181 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
182 {
183 	return key_task_permission(key_ref, current_cred(), perm);
184 }
185 
186 /*
187  * Authorisation record for request_key().
188  */
189 struct request_key_auth {
190 	struct key		*target_key;
191 	struct key		*dest_keyring;
192 	const struct cred	*cred;
193 	void			*callout_info;
194 	size_t			callout_len;
195 	pid_t			pid;
196 };
197 
198 extern struct key_type key_type_request_key_auth;
199 extern struct key *request_key_auth_new(struct key *target,
200 					const void *callout_info,
201 					size_t callout_len,
202 					struct key *dest_keyring);
203 
204 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
205 
206 /*
207  * Determine whether a key is dead.
208  */
209 static inline bool key_is_dead(const struct key *key, time_t limit)
210 {
211 	return
212 		key->flags & ((1 << KEY_FLAG_DEAD) |
213 			      (1 << KEY_FLAG_INVALIDATED)) ||
214 		(key->expiry > 0 && key->expiry <= limit);
215 }
216 
217 /*
218  * keyctl() functions
219  */
220 extern long keyctl_get_keyring_ID(key_serial_t, int);
221 extern long keyctl_join_session_keyring(const char __user *);
222 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
223 extern long keyctl_revoke_key(key_serial_t);
224 extern long keyctl_keyring_clear(key_serial_t);
225 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
226 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
227 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
228 extern long keyctl_keyring_search(key_serial_t, const char __user *,
229 				  const char __user *, key_serial_t);
230 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
231 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
232 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
233 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
234 				   size_t, key_serial_t);
235 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
236 extern long keyctl_set_reqkey_keyring(int);
237 extern long keyctl_set_timeout(key_serial_t, unsigned);
238 extern long keyctl_assume_authority(key_serial_t);
239 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
240 				size_t buflen);
241 extern long keyctl_session_to_parent(void);
242 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
243 extern long keyctl_instantiate_key_iov(key_serial_t,
244 				       const struct iovec __user *,
245 				       unsigned, key_serial_t);
246 extern long keyctl_invalidate_key(key_serial_t);
247 
248 struct iov_iter;
249 extern long keyctl_instantiate_key_common(key_serial_t,
250 					  struct iov_iter *,
251 					  key_serial_t);
252 #ifdef CONFIG_PERSISTENT_KEYRINGS
253 extern long keyctl_get_persistent(uid_t, key_serial_t);
254 extern unsigned persistent_keyring_expiry;
255 #else
256 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
257 {
258 	return -EOPNOTSUPP;
259 }
260 #endif
261 
262 #ifdef CONFIG_KEY_DH_OPERATIONS
263 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
264 			      size_t, void __user *);
265 #else
266 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
267 				     char __user *buffer, size_t buflen,
268 				     void __user *reserved)
269 {
270 	return -EOPNOTSUPP;
271 }
272 #endif
273 
274 /*
275  * Debugging key validation
276  */
277 #ifdef KEY_DEBUGGING
278 extern void __key_check(const struct key *);
279 
280 static inline void key_check(const struct key *key)
281 {
282 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
283 		__key_check(key);
284 }
285 
286 #else
287 
288 #define key_check(key) do {} while(0)
289 
290 #endif
291 
292 #endif /* _INTERNAL_H */
293