xref: /linux/security/keys/internal.h (revision 6a87e0f0ce1ae8d70566935215430e718ea776ff)
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 extern struct key *keyring_search_instkey(struct key *keyring,
113 					  key_serial_t target_id);
114 
115 extern int iterate_over_keyring(const struct key *keyring,
116 				int (*func)(const struct key *key, void *data),
117 				void *data);
118 
119 struct keyring_search_context {
120 	struct keyring_index_key index_key;
121 	const struct cred	*cred;
122 	struct key_match_data	match_data;
123 	unsigned		flags;
124 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
125 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
126 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
127 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
128 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
129 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
130 #define KEYRING_SEARCH_RECURSE		0x0040	/* Search child keyrings also */
131 
132 	int (*iterator)(const void *object, void *iterator_data);
133 
134 	/* Internal stuff */
135 	int			skipped_ret;
136 	bool			possessed;
137 	key_ref_t		result;
138 	time64_t		now;
139 };
140 
141 extern bool key_default_cmp(const struct key *key,
142 			    const struct key_match_data *match_data);
143 extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
144 				    struct keyring_search_context *ctx);
145 
146 extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
147 extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
148 
149 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
150 
151 extern int look_up_user_keyrings(struct key **, struct key **);
152 extern struct key *get_user_session_keyring_rcu(const struct cred *);
153 extern int install_thread_keyring_to_cred(struct cred *);
154 extern int install_process_keyring_to_cred(struct cred *);
155 extern int install_session_keyring_to_cred(struct cred *, struct key *);
156 
157 extern struct key *request_key_and_link(struct key_type *type,
158 					const char *description,
159 					struct key_tag *domain_tag,
160 					const void *callout_info,
161 					size_t callout_len,
162 					void *aux,
163 					struct key *dest_keyring,
164 					unsigned long flags);
165 
166 extern bool lookup_user_key_possessed(const struct key *key,
167 				      const struct key_match_data *match_data);
168 
169 extern long join_session_keyring(const char *name);
170 extern void key_change_session_keyring(struct callback_head *twork);
171 
172 extern struct work_struct key_gc_work;
173 extern unsigned key_gc_delay;
174 extern void keyring_gc(struct key *keyring, time64_t limit);
175 extern void keyring_restriction_gc(struct key *keyring,
176 				   struct key_type *dead_type);
177 extern void key_schedule_gc(time64_t gc_at);
178 extern void key_schedule_gc_links(void);
179 extern void key_gc_keytype(struct key_type *ktype);
180 
181 extern int key_task_permission(const key_ref_t key_ref,
182 			       const struct cred *cred,
183 			       enum key_need_perm need_perm);
184 
185 static inline void notify_key(struct key *key,
186 			      enum key_notification_subtype subtype, u32 aux)
187 {
188 #ifdef CONFIG_KEY_NOTIFICATIONS
189 	struct key_notification n = {
190 		.watch.type	= WATCH_TYPE_KEY_NOTIFY,
191 		.watch.subtype	= subtype,
192 		.watch.info	= watch_sizeof(n),
193 		.key_id		= key_serial(key),
194 		.aux		= aux,
195 	};
196 
197 	post_watch_notification(key->watchers, &n.watch, current_cred(),
198 				n.key_id);
199 #endif
200 }
201 
202 /*
203  * Check to see whether permission is granted to use a key in the desired way.
204  */
205 static inline int key_permission(const key_ref_t key_ref,
206 				 enum key_need_perm need_perm)
207 {
208 	return key_task_permission(key_ref, current_cred(), need_perm);
209 }
210 
211 extern struct key_type key_type_request_key_auth;
212 extern struct key *request_key_auth_new(struct key *target,
213 					const char *op,
214 					const void *callout_info,
215 					size_t callout_len,
216 					struct key *dest_keyring);
217 
218 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
219 
220 /*
221  * Determine whether a key is dead.
222  */
223 static inline bool key_is_dead(const struct key *key, time64_t limit)
224 {
225 	return
226 		key->flags & ((1 << KEY_FLAG_DEAD) |
227 			      (1 << KEY_FLAG_INVALIDATED)) ||
228 		(key->expiry > 0 && key->expiry <= limit) ||
229 		key->domain_tag->removed;
230 }
231 
232 /*
233  * keyctl() functions
234  */
235 extern long keyctl_get_keyring_ID(key_serial_t, int);
236 extern long keyctl_join_session_keyring(const char __user *);
237 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
238 extern long keyctl_revoke_key(key_serial_t);
239 extern long keyctl_keyring_clear(key_serial_t);
240 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
241 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
242 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
243 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
244 extern long keyctl_keyring_search(key_serial_t, const char __user *,
245 				  const char __user *, key_serial_t);
246 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
247 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
248 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
249 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
250 				   size_t, key_serial_t);
251 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
252 extern long keyctl_set_reqkey_keyring(int);
253 extern long keyctl_set_timeout(key_serial_t, unsigned);
254 extern long keyctl_assume_authority(key_serial_t);
255 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
256 				size_t buflen);
257 extern long keyctl_session_to_parent(void);
258 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
259 extern long keyctl_instantiate_key_iov(key_serial_t,
260 				       const struct iovec __user *,
261 				       unsigned, key_serial_t);
262 extern long keyctl_invalidate_key(key_serial_t);
263 extern long keyctl_restrict_keyring(key_serial_t id,
264 				    const char __user *_type,
265 				    const char __user *_restriction);
266 #ifdef CONFIG_PERSISTENT_KEYRINGS
267 extern long keyctl_get_persistent(uid_t, key_serial_t);
268 extern unsigned persistent_keyring_expiry;
269 #else
270 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
271 {
272 	return -EOPNOTSUPP;
273 }
274 #endif
275 
276 #ifdef CONFIG_KEY_DH_OPERATIONS
277 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
278 			      size_t, struct keyctl_kdf_params __user *);
279 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
280 				size_t, struct keyctl_kdf_params *);
281 #ifdef CONFIG_COMPAT
282 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
283 				char __user *buffer, size_t buflen,
284 				struct compat_keyctl_kdf_params __user *kdf);
285 #endif
286 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
287 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
288 #else
289 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
290 				     char __user *buffer, size_t buflen,
291 				     struct keyctl_kdf_params __user *kdf)
292 {
293 	return -EOPNOTSUPP;
294 }
295 
296 #ifdef CONFIG_COMPAT
297 static inline long compat_keyctl_dh_compute(
298 				struct keyctl_dh_params __user *params,
299 				char __user *buffer, size_t buflen,
300 				struct keyctl_kdf_params __user *kdf)
301 {
302 	return -EOPNOTSUPP;
303 }
304 #endif
305 #endif
306 
307 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
308 extern long keyctl_pkey_query(key_serial_t,
309 			      const char __user *,
310 			      struct keyctl_pkey_query __user *);
311 
312 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
313 			       const char __user *,
314 			       const void __user *, const void __user *);
315 
316 extern long keyctl_pkey_e_d_s(int,
317 			      const struct keyctl_pkey_params __user *,
318 			      const char __user *,
319 			      const void __user *, void __user *);
320 #else
321 static inline long keyctl_pkey_query(key_serial_t id,
322 				     const char __user *_info,
323 				     struct keyctl_pkey_query __user *_res)
324 {
325 	return -EOPNOTSUPP;
326 }
327 
328 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
329 				      const char __user *_info,
330 				      const void __user *_in,
331 				      const void __user *_in2)
332 {
333 	return -EOPNOTSUPP;
334 }
335 
336 static inline long keyctl_pkey_e_d_s(int op,
337 				     const struct keyctl_pkey_params __user *params,
338 				     const char __user *_info,
339 				     const void __user *_in,
340 				     void __user *_out)
341 {
342 	return -EOPNOTSUPP;
343 }
344 #endif
345 
346 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
347 
348 #ifdef CONFIG_KEY_NOTIFICATIONS
349 extern long keyctl_watch_key(key_serial_t, int, int);
350 #else
351 static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
352 {
353 	return -EOPNOTSUPP;
354 }
355 #endif
356 
357 /*
358  * Debugging key validation
359  */
360 #ifdef KEY_DEBUGGING
361 extern void __key_check(const struct key *);
362 
363 static inline void key_check(const struct key *key)
364 {
365 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
366 		__key_check(key);
367 }
368 
369 #else
370 
371 #define key_check(key) do {} while(0)
372 
373 #endif
374 #endif /* _INTERNAL_H */
375