xref: /openbmc/linux/security/keys/internal.h (revision ca481398)
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/wait_bit.h>
17 #include <linux/cred.h>
18 #include <linux/key-type.h>
19 #include <linux/task_work.h>
20 #include <linux/keyctl.h>
21 #include <linux/refcount.h>
22 #include <linux/compat.h>
23 
24 struct iovec;
25 
26 #ifdef __KDEBUG
27 #define kenter(FMT, ...) \
28 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
29 #define kleave(FMT, ...) \
30 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
31 #define kdebug(FMT, ...) \
32 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
33 #else
34 #define kenter(FMT, ...) \
35 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
36 #define kleave(FMT, ...) \
37 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
38 #define kdebug(FMT, ...) \
39 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
40 #endif
41 
42 extern struct key_type key_type_dead;
43 extern struct key_type key_type_user;
44 extern struct key_type key_type_logon;
45 
46 /*****************************************************************************/
47 /*
48  * Keep track of keys for a user.
49  *
50  * This needs to be separate to user_struct to avoid a refcount-loop
51  * (user_struct pins some keyrings which pin this struct).
52  *
53  * We also keep track of keys under request from userspace for this UID here.
54  */
55 struct key_user {
56 	struct rb_node		node;
57 	struct mutex		cons_lock;	/* construction initiation lock */
58 	spinlock_t		lock;
59 	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
60 	atomic_t		nkeys;		/* number of keys */
61 	atomic_t		nikeys;		/* number of instantiated keys */
62 	kuid_t			uid;
63 	int			qnkeys;		/* number of keys allocated to this user */
64 	int			qnbytes;	/* number of bytes allocated to this user */
65 };
66 
67 extern struct rb_root	key_user_tree;
68 extern spinlock_t	key_user_lock;
69 extern struct key_user	root_key_user;
70 
71 extern struct key_user *key_user_lookup(kuid_t uid);
72 extern void key_user_put(struct key_user *user);
73 
74 /*
75  * Key quota limits.
76  * - root has its own separate limits to everyone else
77  */
78 extern unsigned key_quota_root_maxkeys;
79 extern unsigned key_quota_root_maxbytes;
80 extern unsigned key_quota_maxkeys;
81 extern unsigned key_quota_maxbytes;
82 
83 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
84 
85 
86 extern struct kmem_cache *key_jar;
87 extern struct rb_root key_serial_tree;
88 extern spinlock_t key_serial_lock;
89 extern struct mutex key_construction_mutex;
90 extern wait_queue_head_t request_key_conswq;
91 
92 
93 extern struct key_type *key_type_lookup(const char *type);
94 extern void key_type_put(struct key_type *ktype);
95 
96 extern int __key_link_begin(struct key *keyring,
97 			    const struct keyring_index_key *index_key,
98 			    struct assoc_array_edit **_edit);
99 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
100 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
101 extern void __key_link_end(struct key *keyring,
102 			   const struct keyring_index_key *index_key,
103 			   struct assoc_array_edit *edit);
104 
105 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
106 				    const struct keyring_index_key *index_key);
107 
108 extern struct key *keyring_search_instkey(struct key *keyring,
109 					  key_serial_t target_id);
110 
111 extern int iterate_over_keyring(const struct key *keyring,
112 				int (*func)(const struct key *key, void *data),
113 				void *data);
114 
115 struct keyring_search_context {
116 	struct keyring_index_key index_key;
117 	const struct cred	*cred;
118 	struct key_match_data	match_data;
119 	unsigned		flags;
120 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
121 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
122 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
123 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
124 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
125 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
126 
127 	int (*iterator)(const void *object, void *iterator_data);
128 
129 	/* Internal stuff */
130 	int			skipped_ret;
131 	bool			possessed;
132 	key_ref_t		result;
133 	struct timespec		now;
134 };
135 
136 extern bool key_default_cmp(const struct key *key,
137 			    const struct key_match_data *match_data);
138 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
139 				    struct keyring_search_context *ctx);
140 
141 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
142 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
143 
144 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
145 
146 extern int install_user_keyrings(void);
147 extern int install_thread_keyring_to_cred(struct cred *);
148 extern int install_process_keyring_to_cred(struct cred *);
149 extern int install_session_keyring_to_cred(struct cred *, struct key *);
150 
151 extern struct key *request_key_and_link(struct key_type *type,
152 					const char *description,
153 					const void *callout_info,
154 					size_t callout_len,
155 					void *aux,
156 					struct key *dest_keyring,
157 					unsigned long flags);
158 
159 extern bool lookup_user_key_possessed(const struct key *key,
160 				      const struct key_match_data *match_data);
161 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
162 				 key_perm_t perm);
163 #define KEY_LOOKUP_CREATE	0x01
164 #define KEY_LOOKUP_PARTIAL	0x02
165 #define KEY_LOOKUP_FOR_UNLINK	0x04
166 
167 extern long join_session_keyring(const char *name);
168 extern void key_change_session_keyring(struct callback_head *twork);
169 
170 extern struct work_struct key_gc_work;
171 extern unsigned key_gc_delay;
172 extern void keyring_gc(struct key *keyring, time_t limit);
173 extern void keyring_restriction_gc(struct key *keyring,
174 				   struct key_type *dead_type);
175 extern void key_schedule_gc(time_t gc_at);
176 extern void key_schedule_gc_links(void);
177 extern void key_gc_keytype(struct key_type *ktype);
178 
179 extern int key_task_permission(const key_ref_t key_ref,
180 			       const struct cred *cred,
181 			       key_perm_t perm);
182 
183 /*
184  * Check to see whether permission is granted to use a key in the desired way.
185  */
186 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
187 {
188 	return key_task_permission(key_ref, current_cred(), perm);
189 }
190 
191 /*
192  * Authorisation record for request_key().
193  */
194 struct request_key_auth {
195 	struct key		*target_key;
196 	struct key		*dest_keyring;
197 	const struct cred	*cred;
198 	void			*callout_info;
199 	size_t			callout_len;
200 	pid_t			pid;
201 } __randomize_layout;
202 
203 extern struct key_type key_type_request_key_auth;
204 extern struct key *request_key_auth_new(struct key *target,
205 					const void *callout_info,
206 					size_t callout_len,
207 					struct key *dest_keyring);
208 
209 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
210 
211 /*
212  * Determine whether a key is dead.
213  */
214 static inline bool key_is_dead(const struct key *key, time_t limit)
215 {
216 	return
217 		key->flags & ((1 << KEY_FLAG_DEAD) |
218 			      (1 << KEY_FLAG_INVALIDATED)) ||
219 		(key->expiry > 0 && key->expiry <= limit);
220 }
221 
222 /*
223  * keyctl() functions
224  */
225 extern long keyctl_get_keyring_ID(key_serial_t, int);
226 extern long keyctl_join_session_keyring(const char __user *);
227 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
228 extern long keyctl_revoke_key(key_serial_t);
229 extern long keyctl_keyring_clear(key_serial_t);
230 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
231 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
232 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
233 extern long keyctl_keyring_search(key_serial_t, const char __user *,
234 				  const char __user *, key_serial_t);
235 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
236 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
237 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
238 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
239 				   size_t, key_serial_t);
240 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
241 extern long keyctl_set_reqkey_keyring(int);
242 extern long keyctl_set_timeout(key_serial_t, unsigned);
243 extern long keyctl_assume_authority(key_serial_t);
244 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
245 				size_t buflen);
246 extern long keyctl_session_to_parent(void);
247 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
248 extern long keyctl_instantiate_key_iov(key_serial_t,
249 				       const struct iovec __user *,
250 				       unsigned, key_serial_t);
251 extern long keyctl_invalidate_key(key_serial_t);
252 
253 struct iov_iter;
254 extern long keyctl_instantiate_key_common(key_serial_t,
255 					  struct iov_iter *,
256 					  key_serial_t);
257 extern long keyctl_restrict_keyring(key_serial_t id,
258 				    const char __user *_type,
259 				    const char __user *_restriction);
260 #ifdef CONFIG_PERSISTENT_KEYRINGS
261 extern long keyctl_get_persistent(uid_t, key_serial_t);
262 extern unsigned persistent_keyring_expiry;
263 #else
264 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
265 {
266 	return -EOPNOTSUPP;
267 }
268 #endif
269 
270 #ifdef CONFIG_KEY_DH_OPERATIONS
271 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
272 			      size_t, struct keyctl_kdf_params __user *);
273 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
274 				size_t, struct keyctl_kdf_params *);
275 #ifdef CONFIG_KEYS_COMPAT
276 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
277 				char __user *buffer, size_t buflen,
278 				struct compat_keyctl_kdf_params __user *kdf);
279 #endif
280 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
281 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
282 #else
283 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
284 				     char __user *buffer, size_t buflen,
285 				     struct keyctl_kdf_params __user *kdf)
286 {
287 	return -EOPNOTSUPP;
288 }
289 
290 #ifdef CONFIG_KEYS_COMPAT
291 static inline long compat_keyctl_dh_compute(
292 				struct keyctl_dh_params __user *params,
293 				char __user *buffer, size_t buflen,
294 				struct keyctl_kdf_params __user *kdf)
295 {
296 	return -EOPNOTSUPP;
297 }
298 #endif
299 #endif
300 
301 /*
302  * Debugging key validation
303  */
304 #ifdef KEY_DEBUGGING
305 extern void __key_check(const struct key *);
306 
307 static inline void key_check(const struct key *key)
308 {
309 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
310 		__key_check(key);
311 }
312 
313 #else
314 
315 #define key_check(key) do {} while(0)
316 
317 #endif
318 
319 #endif /* _INTERNAL_H */
320