xref: /openbmc/linux/security/keys/internal.h (revision a9ebfc40)
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 void key_set_expiry(struct key *key, time64_t expiry);
178 extern void key_schedule_gc(time64_t gc_at);
179 extern void key_schedule_gc_links(void);
180 extern void key_gc_keytype(struct key_type *ktype);
181 
182 extern int key_task_permission(const key_ref_t key_ref,
183 			       const struct cred *cred,
184 			       enum key_need_perm need_perm);
185 
186 static inline void notify_key(struct key *key,
187 			      enum key_notification_subtype subtype, u32 aux)
188 {
189 #ifdef CONFIG_KEY_NOTIFICATIONS
190 	struct key_notification n = {
191 		.watch.type	= WATCH_TYPE_KEY_NOTIFY,
192 		.watch.subtype	= subtype,
193 		.watch.info	= watch_sizeof(n),
194 		.key_id		= key_serial(key),
195 		.aux		= aux,
196 	};
197 
198 	post_watch_notification(key->watchers, &n.watch, current_cred(),
199 				n.key_id);
200 #endif
201 }
202 
203 /*
204  * Check to see whether permission is granted to use a key in the desired way.
205  */
206 static inline int key_permission(const key_ref_t key_ref,
207 				 enum key_need_perm need_perm)
208 {
209 	return key_task_permission(key_ref, current_cred(), need_perm);
210 }
211 
212 extern struct key_type key_type_request_key_auth;
213 extern struct key *request_key_auth_new(struct key *target,
214 					const char *op,
215 					const void *callout_info,
216 					size_t callout_len,
217 					struct key *dest_keyring);
218 
219 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
220 
221 /*
222  * Determine whether a key is dead.
223  */
224 static inline bool key_is_dead(const struct key *key, time64_t limit)
225 {
226 	time64_t expiry = key->expiry;
227 
228 	if (expiry != TIME64_MAX) {
229 		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
230 			expiry += key_gc_delay;
231 		if (expiry <= limit)
232 			return true;
233 	}
234 
235 	return
236 		key->flags & ((1 << KEY_FLAG_DEAD) |
237 			      (1 << KEY_FLAG_INVALIDATED)) ||
238 		key->domain_tag->removed;
239 }
240 
241 /*
242  * keyctl() functions
243  */
244 extern long keyctl_get_keyring_ID(key_serial_t, int);
245 extern long keyctl_join_session_keyring(const char __user *);
246 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
247 extern long keyctl_revoke_key(key_serial_t);
248 extern long keyctl_keyring_clear(key_serial_t);
249 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
250 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
251 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
252 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
253 extern long keyctl_keyring_search(key_serial_t, const char __user *,
254 				  const char __user *, key_serial_t);
255 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
256 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
257 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
258 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
259 				   size_t, key_serial_t);
260 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
261 extern long keyctl_set_reqkey_keyring(int);
262 extern long keyctl_set_timeout(key_serial_t, unsigned);
263 extern long keyctl_assume_authority(key_serial_t);
264 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
265 				size_t buflen);
266 extern long keyctl_session_to_parent(void);
267 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
268 extern long keyctl_instantiate_key_iov(key_serial_t,
269 				       const struct iovec __user *,
270 				       unsigned, key_serial_t);
271 extern long keyctl_invalidate_key(key_serial_t);
272 extern long keyctl_restrict_keyring(key_serial_t id,
273 				    const char __user *_type,
274 				    const char __user *_restriction);
275 #ifdef CONFIG_PERSISTENT_KEYRINGS
276 extern long keyctl_get_persistent(uid_t, key_serial_t);
277 extern unsigned persistent_keyring_expiry;
278 #else
279 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
280 {
281 	return -EOPNOTSUPP;
282 }
283 #endif
284 
285 #ifdef CONFIG_KEY_DH_OPERATIONS
286 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
287 			      size_t, struct keyctl_kdf_params __user *);
288 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
289 				size_t, struct keyctl_kdf_params *);
290 #ifdef CONFIG_COMPAT
291 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
292 				char __user *buffer, size_t buflen,
293 				struct compat_keyctl_kdf_params __user *kdf);
294 #endif
295 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
296 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
297 #else
298 static inline long keyctl_dh_compute(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 
305 #ifdef CONFIG_COMPAT
306 static inline long compat_keyctl_dh_compute(
307 				struct keyctl_dh_params __user *params,
308 				char __user *buffer, size_t buflen,
309 				struct keyctl_kdf_params __user *kdf)
310 {
311 	return -EOPNOTSUPP;
312 }
313 #endif
314 #endif
315 
316 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
317 extern long keyctl_pkey_query(key_serial_t,
318 			      const char __user *,
319 			      struct keyctl_pkey_query __user *);
320 
321 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
322 			       const char __user *,
323 			       const void __user *, const void __user *);
324 
325 extern long keyctl_pkey_e_d_s(int,
326 			      const struct keyctl_pkey_params __user *,
327 			      const char __user *,
328 			      const void __user *, void __user *);
329 #else
330 static inline long keyctl_pkey_query(key_serial_t id,
331 				     const char __user *_info,
332 				     struct keyctl_pkey_query __user *_res)
333 {
334 	return -EOPNOTSUPP;
335 }
336 
337 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
338 				      const char __user *_info,
339 				      const void __user *_in,
340 				      const void __user *_in2)
341 {
342 	return -EOPNOTSUPP;
343 }
344 
345 static inline long keyctl_pkey_e_d_s(int op,
346 				     const struct keyctl_pkey_params __user *params,
347 				     const char __user *_info,
348 				     const void __user *_in,
349 				     void __user *_out)
350 {
351 	return -EOPNOTSUPP;
352 }
353 #endif
354 
355 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
356 
357 #ifdef CONFIG_KEY_NOTIFICATIONS
358 extern long keyctl_watch_key(key_serial_t, int, int);
359 #else
360 static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
361 {
362 	return -EOPNOTSUPP;
363 }
364 #endif
365 
366 /*
367  * Debugging key validation
368  */
369 #ifdef KEY_DEBUGGING
370 extern void __key_check(const struct key *);
371 
372 static inline void key_check(const struct key *key)
373 {
374 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
375 		__key_check(key);
376 }
377 
378 #else
379 
380 #define key_check(key) do {} while(0)
381 
382 #endif
383 #endif /* _INTERNAL_H */
384