xref: /openbmc/linux/security/keys/internal.h (revision 232b0b08)
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 #include <linux/refcount.h>
21 
22 struct iovec;
23 
24 #ifdef __KDEBUG
25 #define kenter(FMT, ...) \
26 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
27 #define kleave(FMT, ...) \
28 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
29 #define kdebug(FMT, ...) \
30 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
31 #else
32 #define kenter(FMT, ...) \
33 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
34 #define kleave(FMT, ...) \
35 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
36 #define kdebug(FMT, ...) \
37 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
38 #endif
39 
40 extern struct key_type key_type_dead;
41 extern struct key_type key_type_user;
42 extern struct key_type key_type_logon;
43 
44 /*****************************************************************************/
45 /*
46  * Keep track of keys for a user.
47  *
48  * This needs to be separate to user_struct to avoid a refcount-loop
49  * (user_struct pins some keyrings which pin this struct).
50  *
51  * We also keep track of keys under request from userspace for this UID here.
52  */
53 struct key_user {
54 	struct rb_node		node;
55 	struct mutex		cons_lock;	/* construction initiation lock */
56 	spinlock_t		lock;
57 	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
58 	atomic_t		nkeys;		/* number of keys */
59 	atomic_t		nikeys;		/* number of instantiated keys */
60 	kuid_t			uid;
61 	int			qnkeys;		/* number of keys allocated to this user */
62 	int			qnbytes;	/* number of bytes allocated to this user */
63 };
64 
65 extern struct rb_root	key_user_tree;
66 extern spinlock_t	key_user_lock;
67 extern struct key_user	root_key_user;
68 
69 extern struct key_user *key_user_lookup(kuid_t uid);
70 extern void key_user_put(struct key_user *user);
71 
72 /*
73  * Key quota limits.
74  * - root has its own separate limits to everyone else
75  */
76 extern unsigned key_quota_root_maxkeys;
77 extern unsigned key_quota_root_maxbytes;
78 extern unsigned key_quota_maxkeys;
79 extern unsigned key_quota_maxbytes;
80 
81 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
82 
83 
84 extern struct kmem_cache *key_jar;
85 extern struct rb_root key_serial_tree;
86 extern spinlock_t key_serial_lock;
87 extern struct mutex key_construction_mutex;
88 extern wait_queue_head_t request_key_conswq;
89 
90 
91 extern struct key_type *key_type_lookup(const char *type);
92 extern void key_type_put(struct key_type *ktype);
93 
94 extern int __key_link_begin(struct key *keyring,
95 			    const struct keyring_index_key *index_key,
96 			    struct assoc_array_edit **_edit);
97 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
98 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
99 extern void __key_link_end(struct key *keyring,
100 			   const struct keyring_index_key *index_key,
101 			   struct assoc_array_edit *edit);
102 
103 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
104 				    const struct keyring_index_key *index_key);
105 
106 extern struct key *keyring_search_instkey(struct key *keyring,
107 					  key_serial_t target_id);
108 
109 extern int iterate_over_keyring(const struct key *keyring,
110 				int (*func)(const struct key *key, void *data),
111 				void *data);
112 
113 struct keyring_search_context {
114 	struct keyring_index_key index_key;
115 	const struct cred	*cred;
116 	struct key_match_data	match_data;
117 	unsigned		flags;
118 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
119 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
120 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
121 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
122 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
123 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
124 
125 	int (*iterator)(const void *object, void *iterator_data);
126 
127 	/* Internal stuff */
128 	int			skipped_ret;
129 	bool			possessed;
130 	key_ref_t		result;
131 	struct timespec		now;
132 };
133 
134 extern bool key_default_cmp(const struct key *key,
135 			    const struct key_match_data *match_data);
136 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
137 				    struct keyring_search_context *ctx);
138 
139 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
140 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
141 
142 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
143 
144 extern int install_user_keyrings(void);
145 extern int install_thread_keyring_to_cred(struct cred *);
146 extern int install_process_keyring_to_cred(struct cred *);
147 extern int install_session_keyring_to_cred(struct cred *, struct key *);
148 
149 extern struct key *request_key_and_link(struct key_type *type,
150 					const char *description,
151 					const void *callout_info,
152 					size_t callout_len,
153 					void *aux,
154 					struct key *dest_keyring,
155 					unsigned long flags);
156 
157 extern bool lookup_user_key_possessed(const struct key *key,
158 				      const struct key_match_data *match_data);
159 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
160 				 key_perm_t perm);
161 #define KEY_LOOKUP_CREATE	0x01
162 #define KEY_LOOKUP_PARTIAL	0x02
163 #define KEY_LOOKUP_FOR_UNLINK	0x04
164 
165 extern long join_session_keyring(const char *name);
166 extern void key_change_session_keyring(struct callback_head *twork);
167 
168 extern struct work_struct key_gc_work;
169 extern unsigned key_gc_delay;
170 extern void keyring_gc(struct key *keyring, time_t limit);
171 extern void key_schedule_gc(time_t gc_at);
172 extern void key_schedule_gc_links(void);
173 extern void key_gc_keytype(struct key_type *ktype);
174 
175 extern int key_task_permission(const key_ref_t key_ref,
176 			       const struct cred *cred,
177 			       key_perm_t perm);
178 
179 /*
180  * Check to see whether permission is granted to use a key in the desired way.
181  */
182 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
183 {
184 	return key_task_permission(key_ref, current_cred(), perm);
185 }
186 
187 /*
188  * Authorisation record for request_key().
189  */
190 struct request_key_auth {
191 	struct key		*target_key;
192 	struct key		*dest_keyring;
193 	const struct cred	*cred;
194 	void			*callout_info;
195 	size_t			callout_len;
196 	pid_t			pid;
197 };
198 
199 extern struct key_type key_type_request_key_auth;
200 extern struct key *request_key_auth_new(struct key *target,
201 					const void *callout_info,
202 					size_t callout_len,
203 					struct key *dest_keyring);
204 
205 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
206 
207 /*
208  * Determine whether a key is dead.
209  */
210 static inline bool key_is_dead(const struct key *key, time_t limit)
211 {
212 	return
213 		key->flags & ((1 << KEY_FLAG_DEAD) |
214 			      (1 << KEY_FLAG_INVALIDATED)) ||
215 		(key->expiry > 0 && key->expiry <= limit);
216 }
217 
218 /*
219  * keyctl() functions
220  */
221 extern long keyctl_get_keyring_ID(key_serial_t, int);
222 extern long keyctl_join_session_keyring(const char __user *);
223 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
224 extern long keyctl_revoke_key(key_serial_t);
225 extern long keyctl_keyring_clear(key_serial_t);
226 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
227 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
228 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
229 extern long keyctl_keyring_search(key_serial_t, const char __user *,
230 				  const char __user *, key_serial_t);
231 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
232 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
233 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
234 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
235 				   size_t, key_serial_t);
236 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
237 extern long keyctl_set_reqkey_keyring(int);
238 extern long keyctl_set_timeout(key_serial_t, unsigned);
239 extern long keyctl_assume_authority(key_serial_t);
240 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
241 				size_t buflen);
242 extern long keyctl_session_to_parent(void);
243 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
244 extern long keyctl_instantiate_key_iov(key_serial_t,
245 				       const struct iovec __user *,
246 				       unsigned, key_serial_t);
247 extern long keyctl_invalidate_key(key_serial_t);
248 
249 struct iov_iter;
250 extern long keyctl_instantiate_key_common(key_serial_t,
251 					  struct iov_iter *,
252 					  key_serial_t);
253 #ifdef CONFIG_PERSISTENT_KEYRINGS
254 extern long keyctl_get_persistent(uid_t, key_serial_t);
255 extern unsigned persistent_keyring_expiry;
256 #else
257 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
258 {
259 	return -EOPNOTSUPP;
260 }
261 #endif
262 
263 #ifdef CONFIG_KEY_DH_OPERATIONS
264 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
265 			      size_t, void __user *);
266 #else
267 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
268 				     char __user *buffer, size_t buflen,
269 				     void __user *reserved)
270 {
271 	return -EOPNOTSUPP;
272 }
273 #endif
274 
275 /*
276  * Debugging key validation
277  */
278 #ifdef KEY_DEBUGGING
279 extern void __key_check(const struct key *);
280 
281 static inline void key_check(const struct key *key)
282 {
283 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
284 		__key_check(key);
285 }
286 
287 #else
288 
289 #define key_check(key) do {} while(0)
290 
291 #endif
292 
293 #endif /* _INTERNAL_H */
294