xref: /linux/security/keys/internal.h (revision d0fde6aae2bacdc024fff43461ba0f325375fa97)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* Authentication token and access key management internal defs
3  *
4  * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #ifndef _INTERNAL_H
9 #define _INTERNAL_H
10 
11 #include <linux/sched.h>
12 #include <linux/wait_bit.h>
13 #include <linux/cred.h>
14 #include <linux/key-type.h>
15 #include <linux/task_work.h>
16 #include <linux/keyctl.h>
17 #include <linux/refcount.h>
18 #include <linux/watch_queue.h>
19 #include <linux/compat.h>
20 #include <linux/mm.h>
21 #include <linux/vmalloc.h>
22 
23 struct iovec;
24 
25 #ifdef __KDEBUG
26 #define kenter(FMT, ...) \
27 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
28 #define kleave(FMT, ...) \
29 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
30 #define kdebug(FMT, ...) \
31 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
32 #else
33 #define kenter(FMT, ...) \
34 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
35 #define kleave(FMT, ...) \
36 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
37 #define kdebug(FMT, ...) \
38 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
39 #endif
40 
41 extern struct key_type key_type_dead;
42 extern struct key_type key_type_user;
43 extern struct key_type key_type_logon;
44 
45 /*****************************************************************************/
46 /*
47  * Keep track of keys for a user.
48  *
49  * This needs to be separate to user_struct to avoid a refcount-loop
50  * (user_struct pins some keyrings which pin this struct).
51  *
52  * We also keep track of keys under request from userspace for this UID here.
53  */
54 struct key_user {
55 	struct rb_node		node;
56 	struct mutex		cons_lock;	/* construction initiation lock */
57 	spinlock_t		lock;
58 	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
59 	atomic_t		nkeys;		/* number of keys */
60 	atomic_t		nikeys;		/* number of instantiated keys */
61 	kuid_t			uid;
62 	int			qnkeys;		/* number of keys allocated to this user */
63 	int			qnbytes;	/* number of bytes allocated to this user */
64 };
65 
66 extern struct rb_root	key_user_tree;
67 extern spinlock_t	key_user_lock;
68 extern struct key_user	root_key_user;
69 
70 extern struct key_user *key_user_lookup(kuid_t uid);
71 extern void key_user_put(struct key_user *user);
72 
73 /*
74  * Key quota limits.
75  * - root has its own separate limits to everyone else
76  */
77 extern unsigned key_quota_root_maxkeys;
78 extern unsigned key_quota_root_maxbytes;
79 extern unsigned key_quota_maxkeys;
80 extern unsigned key_quota_maxbytes;
81 
82 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
83 
84 
85 extern struct kmem_cache *key_jar;
86 extern struct rb_root key_serial_tree;
87 extern spinlock_t key_serial_lock;
88 extern struct mutex key_construction_mutex;
89 extern wait_queue_head_t request_key_conswq;
90 
91 extern void key_set_index_key(struct keyring_index_key *index_key);
92 extern struct key_type *key_type_lookup(const char *type);
93 extern void key_type_put(struct key_type *ktype);
94 
95 extern int __key_link_lock(struct key *keyring,
96 			   const struct keyring_index_key *index_key);
97 extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
98 			   const struct keyring_index_key *index_key);
99 extern int __key_link_begin(struct key *keyring,
100 			    const struct keyring_index_key *index_key,
101 			    struct assoc_array_edit **_edit);
102 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
103 extern void __key_link(struct key *keyring, struct key *key,
104 		       struct assoc_array_edit **_edit);
105 extern void __key_link_end(struct key *keyring,
106 			   const struct keyring_index_key *index_key,
107 			   struct assoc_array_edit *edit);
108 
109 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
110 				    const struct keyring_index_key *index_key);
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 #define KEYRING_SEARCH_RECURSE		0x0040	/* Search child keyrings also */
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 	time64_t		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_rcu(key_ref_t keyring_ref,
137 				    struct keyring_search_context *ctx);
138 
139 extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
140 extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
141 
142 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
143 
144 extern int look_up_user_keyrings(struct key **, struct key **);
145 extern struct key *get_user_session_keyring_rcu(const struct cred *);
146 extern int install_thread_keyring_to_cred(struct cred *);
147 extern int install_process_keyring_to_cred(struct cred *);
148 extern int install_session_keyring_to_cred(struct cred *, struct key *);
149 
150 extern struct key *request_key_and_link(struct key_type *type,
151 					const char *description,
152 					struct key_tag *domain_tag,
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 
162 extern long join_session_keyring(const char *name);
163 extern void key_change_session_keyring(struct callback_head *twork);
164 
165 extern struct work_struct key_gc_work;
166 extern unsigned key_gc_delay;
167 extern void keyring_gc(struct key *keyring, time64_t limit);
168 extern void keyring_restriction_gc(struct key *keyring,
169 				   struct key_type *dead_type);
170 extern void key_schedule_gc(time64_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 			       enum key_need_perm need_perm);
177 
178 static inline void notify_key(struct key *key,
179 			      enum key_notification_subtype subtype, u32 aux)
180 {
181 #ifdef CONFIG_KEY_NOTIFICATIONS
182 	struct key_notification n = {
183 		.watch.type	= WATCH_TYPE_KEY_NOTIFY,
184 		.watch.subtype	= subtype,
185 		.watch.info	= watch_sizeof(n),
186 		.key_id		= key_serial(key),
187 		.aux		= aux,
188 	};
189 
190 	post_watch_notification(key->watchers, &n.watch, current_cred(),
191 				n.key_id);
192 #endif
193 }
194 
195 /*
196  * Check to see whether permission is granted to use a key in the desired way.
197  */
198 static inline int key_permission(const key_ref_t key_ref,
199 				 enum key_need_perm need_perm)
200 {
201 	return key_task_permission(key_ref, current_cred(), need_perm);
202 }
203 
204 extern struct key_type key_type_request_key_auth;
205 extern struct key *request_key_auth_new(struct key *target,
206 					const char *op,
207 					const void *callout_info,
208 					size_t callout_len,
209 					struct key *dest_keyring);
210 
211 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
212 
213 /*
214  * Determine whether a key is dead.
215  */
216 static inline bool key_is_dead(const struct key *key, time64_t limit)
217 {
218 	return
219 		key->flags & ((1 << KEY_FLAG_DEAD) |
220 			      (1 << KEY_FLAG_INVALIDATED)) ||
221 		(key->expiry > 0 && key->expiry <= limit) ||
222 		key->domain_tag->removed;
223 }
224 
225 /*
226  * keyctl() functions
227  */
228 extern long keyctl_get_keyring_ID(key_serial_t, int);
229 extern long keyctl_join_session_keyring(const char __user *);
230 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
231 extern long keyctl_revoke_key(key_serial_t);
232 extern long keyctl_keyring_clear(key_serial_t);
233 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
234 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
235 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
236 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
237 extern long keyctl_keyring_search(key_serial_t, const char __user *,
238 				  const char __user *, key_serial_t);
239 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
240 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
241 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
242 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
243 				   size_t, key_serial_t);
244 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
245 extern long keyctl_set_reqkey_keyring(int);
246 extern long keyctl_set_timeout(key_serial_t, unsigned);
247 extern long keyctl_assume_authority(key_serial_t);
248 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
249 				size_t buflen);
250 extern long keyctl_session_to_parent(void);
251 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
252 extern long keyctl_instantiate_key_iov(key_serial_t,
253 				       const struct iovec __user *,
254 				       unsigned, key_serial_t);
255 extern long keyctl_invalidate_key(key_serial_t);
256 extern long keyctl_restrict_keyring(key_serial_t id,
257 				    const char __user *_type,
258 				    const char __user *_restriction);
259 #ifdef CONFIG_PERSISTENT_KEYRINGS
260 extern long keyctl_get_persistent(uid_t, key_serial_t);
261 extern unsigned persistent_keyring_expiry;
262 #else
263 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
264 {
265 	return -EOPNOTSUPP;
266 }
267 #endif
268 
269 #ifdef CONFIG_KEY_DH_OPERATIONS
270 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
271 			      size_t, struct keyctl_kdf_params __user *);
272 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
273 				size_t, struct keyctl_kdf_params *);
274 #ifdef CONFIG_COMPAT
275 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
276 				char __user *buffer, size_t buflen,
277 				struct compat_keyctl_kdf_params __user *kdf);
278 #endif
279 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
280 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
281 #else
282 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
283 				     char __user *buffer, size_t buflen,
284 				     struct keyctl_kdf_params __user *kdf)
285 {
286 	return -EOPNOTSUPP;
287 }
288 
289 #ifdef CONFIG_COMPAT
290 static inline long compat_keyctl_dh_compute(
291 				struct keyctl_dh_params __user *params,
292 				char __user *buffer, size_t buflen,
293 				struct keyctl_kdf_params __user *kdf)
294 {
295 	return -EOPNOTSUPP;
296 }
297 #endif
298 #endif
299 
300 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
301 extern long keyctl_pkey_query(key_serial_t,
302 			      const char __user *,
303 			      struct keyctl_pkey_query __user *);
304 
305 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
306 			       const char __user *,
307 			       const void __user *, const void __user *);
308 
309 extern long keyctl_pkey_e_d_s(int,
310 			      const struct keyctl_pkey_params __user *,
311 			      const char __user *,
312 			      const void __user *, void __user *);
313 #else
314 static inline long keyctl_pkey_query(key_serial_t id,
315 				     const char __user *_info,
316 				     struct keyctl_pkey_query __user *_res)
317 {
318 	return -EOPNOTSUPP;
319 }
320 
321 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
322 				      const char __user *_info,
323 				      const void __user *_in,
324 				      const void __user *_in2)
325 {
326 	return -EOPNOTSUPP;
327 }
328 
329 static inline long keyctl_pkey_e_d_s(int op,
330 				     const struct keyctl_pkey_params __user *params,
331 				     const char __user *_info,
332 				     const void __user *_in,
333 				     void __user *_out)
334 {
335 	return -EOPNOTSUPP;
336 }
337 #endif
338 
339 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
340 
341 #ifdef CONFIG_KEY_NOTIFICATIONS
342 extern long keyctl_watch_key(key_serial_t, int, int);
343 #else
344 static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
345 {
346 	return -EOPNOTSUPP;
347 }
348 #endif
349 
350 /*
351  * Debugging key validation
352  */
353 #ifdef KEY_DEBUGGING
354 extern void __key_check(const struct key *);
355 
356 static inline void key_check(const struct key *key)
357 {
358 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
359 		__key_check(key);
360 }
361 
362 #else
363 
364 #define key_check(key) do {} while(0)
365 
366 #endif
367 #endif /* _INTERNAL_H */
368