xref: /linux/security/keys/internal.h (revision fd15b457a86939c38aa12116adabd8ff686c5e51)
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 void key_set_expiry(struct key *key, time64_t expiry);
171 extern void key_schedule_gc(time64_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 			       enum key_need_perm need_perm);
178 
179 static inline void notify_key(struct key *key,
180 			      enum key_notification_subtype subtype, u32 aux)
181 {
182 #ifdef CONFIG_KEY_NOTIFICATIONS
183 	struct key_notification n = {
184 		.watch.type	= WATCH_TYPE_KEY_NOTIFY,
185 		.watch.subtype	= subtype,
186 		.watch.info	= watch_sizeof(n),
187 		.key_id		= key_serial(key),
188 		.aux		= aux,
189 	};
190 
191 	post_watch_notification(key->watchers, &n.watch, current_cred(),
192 				n.key_id);
193 #endif
194 }
195 
196 /*
197  * Check to see whether permission is granted to use a key in the desired way.
198  */
199 static inline int key_permission(const key_ref_t key_ref,
200 				 enum key_need_perm need_perm)
201 {
202 	return key_task_permission(key_ref, current_cred(), need_perm);
203 }
204 
205 extern struct key_type key_type_request_key_auth;
206 extern struct key *request_key_auth_new(struct key *target,
207 					const char *op,
208 					const void *callout_info,
209 					size_t callout_len,
210 					struct key *dest_keyring);
211 struct request_key_auth *request_key_auth_get(struct key *authkey);
212 void request_key_auth_put(struct request_key_auth *rka);
213 
214 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
215 
216 /*
217  * Determine whether a key is dead.
218  */
219 static inline bool key_is_dead(const struct key *key, time64_t limit)
220 {
221 	time64_t expiry = key->expiry;
222 
223 	if (expiry != TIME64_MAX) {
224 		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
225 			expiry += key_gc_delay;
226 		if (expiry <= limit)
227 			return true;
228 	}
229 
230 	return
231 		key->flags & ((1 << KEY_FLAG_DEAD) |
232 			      (1 << KEY_FLAG_INVALIDATED)) ||
233 		key->domain_tag->removed;
234 }
235 
236 /*
237  * keyctl() functions
238  */
239 extern long keyctl_get_keyring_ID(key_serial_t, int);
240 extern long keyctl_join_session_keyring(const char __user *);
241 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
242 extern long keyctl_revoke_key(key_serial_t);
243 extern long keyctl_keyring_clear(key_serial_t);
244 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
245 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
246 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
247 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
248 extern long keyctl_keyring_search(key_serial_t, const char __user *,
249 				  const char __user *, key_serial_t);
250 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
251 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
252 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
253 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
254 				   size_t, key_serial_t);
255 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
256 extern long keyctl_set_reqkey_keyring(int);
257 extern long keyctl_set_timeout(key_serial_t, unsigned);
258 extern long keyctl_assume_authority(key_serial_t);
259 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
260 				size_t buflen);
261 extern long keyctl_session_to_parent(void);
262 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
263 extern long keyctl_instantiate_key_iov(key_serial_t,
264 				       const struct iovec __user *,
265 				       unsigned, key_serial_t);
266 extern long keyctl_invalidate_key(key_serial_t);
267 extern long keyctl_restrict_keyring(key_serial_t id,
268 				    const char __user *_type,
269 				    const char __user *_restriction);
270 #ifdef CONFIG_PERSISTENT_KEYRINGS
271 extern long keyctl_get_persistent(uid_t, key_serial_t);
272 extern unsigned persistent_keyring_expiry;
273 #else
274 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
275 {
276 	return -EOPNOTSUPP;
277 }
278 #endif
279 
280 #ifdef CONFIG_KEY_DH_OPERATIONS
281 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
282 			      size_t, struct keyctl_kdf_params __user *);
283 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
284 				size_t, struct keyctl_kdf_params *);
285 #ifdef CONFIG_COMPAT
286 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
287 				char __user *buffer, size_t buflen,
288 				struct compat_keyctl_kdf_params __user *kdf);
289 #endif
290 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
291 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
292 #else
293 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
294 				     char __user *buffer, size_t buflen,
295 				     struct keyctl_kdf_params __user *kdf)
296 {
297 	return -EOPNOTSUPP;
298 }
299 
300 #ifdef CONFIG_COMPAT
301 static inline long compat_keyctl_dh_compute(
302 				struct keyctl_dh_params __user *params,
303 				char __user *buffer, size_t buflen,
304 				struct keyctl_kdf_params __user *kdf)
305 {
306 	return -EOPNOTSUPP;
307 }
308 #endif
309 #endif
310 
311 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
312 extern long keyctl_pkey_query(key_serial_t,
313 			      const char __user *,
314 			      struct keyctl_pkey_query __user *);
315 
316 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
317 			       const char __user *,
318 			       const void __user *, const void __user *);
319 
320 extern long keyctl_pkey_e_d_s(int,
321 			      const struct keyctl_pkey_params __user *,
322 			      const char __user *,
323 			      const void __user *, void __user *);
324 #else
325 static inline long keyctl_pkey_query(key_serial_t id,
326 				     const char __user *_info,
327 				     struct keyctl_pkey_query __user *_res)
328 {
329 	return -EOPNOTSUPP;
330 }
331 
332 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
333 				      const char __user *_info,
334 				      const void __user *_in,
335 				      const void __user *_in2)
336 {
337 	return -EOPNOTSUPP;
338 }
339 
340 static inline long keyctl_pkey_e_d_s(int op,
341 				     const struct keyctl_pkey_params __user *params,
342 				     const char __user *_info,
343 				     const void __user *_in,
344 				     void __user *_out)
345 {
346 	return -EOPNOTSUPP;
347 }
348 #endif
349 
350 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
351 
352 #ifdef CONFIG_KEY_NOTIFICATIONS
353 extern long keyctl_watch_key(key_serial_t, int, int);
354 #else
355 static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
356 {
357 	return -EOPNOTSUPP;
358 }
359 #endif
360 
361 /*
362  * Debugging key validation
363  */
364 #ifdef KEY_DEBUGGING
365 extern void __key_check(const struct key *);
366 
367 static inline void key_check(const struct key *key)
368 {
369 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
370 		__key_check(key);
371 }
372 
373 #else
374 
375 #define key_check(key) do {} while(0)
376 
377 #endif
378 #endif /* _INTERNAL_H */
379