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
23struct 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
41extern struct key_type key_type_dead;
42extern struct key_type key_type_user;
43extern 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 */
54struct 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
66extern struct rb_root	key_user_tree;
67extern spinlock_t	key_user_lock;
68extern struct key_user	root_key_user;
69
70extern struct key_user *key_user_lookup(kuid_t uid);
71extern 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 */
77extern unsigned key_quota_root_maxkeys;
78extern unsigned key_quota_root_maxbytes;
79extern unsigned key_quota_maxkeys;
80extern unsigned key_quota_maxbytes;
81
82#define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
83
84
85extern struct kmem_cache *key_jar;
86extern struct rb_root key_serial_tree;
87extern spinlock_t key_serial_lock;
88extern struct mutex key_construction_mutex;
89extern wait_queue_head_t request_key_conswq;
90
91extern void key_set_index_key(struct keyring_index_key *index_key);
92extern struct key_type *key_type_lookup(const char *type);
93extern void key_type_put(struct key_type *ktype);
94
95extern int __key_link_lock(struct key *keyring,
96			   const struct keyring_index_key *index_key);
97extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
98			   const struct keyring_index_key *index_key);
99extern int __key_link_begin(struct key *keyring,
100			    const struct keyring_index_key *index_key,
101			    struct assoc_array_edit **_edit);
102extern int __key_link_check_live_key(struct key *keyring, struct key *key);
103extern void __key_link(struct key *keyring, struct key *key,
104		       struct assoc_array_edit **_edit);
105extern void __key_link_end(struct key *keyring,
106			   const struct keyring_index_key *index_key,
107			   struct assoc_array_edit *edit);
108
109extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
110				    const struct keyring_index_key *index_key);
111
112extern struct key *keyring_search_instkey(struct key *keyring,
113					  key_serial_t target_id);
114
115extern int iterate_over_keyring(const struct key *keyring,
116				int (*func)(const struct key *key, void *data),
117				void *data);
118
119struct 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
141extern bool key_default_cmp(const struct key *key,
142			    const struct key_match_data *match_data);
143extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
144				    struct keyring_search_context *ctx);
145
146extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
147extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
148
149extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
150
151extern int look_up_user_keyrings(struct key **, struct key **);
152extern struct key *get_user_session_keyring_rcu(const struct cred *);
153extern int install_thread_keyring_to_cred(struct cred *);
154extern int install_process_keyring_to_cred(struct cred *);
155extern int install_session_keyring_to_cred(struct cred *, struct key *);
156
157extern 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
166extern bool lookup_user_key_possessed(const struct key *key,
167				      const struct key_match_data *match_data);
168#define KEY_LOOKUP_CREATE	0x01
169#define KEY_LOOKUP_PARTIAL	0x02
170
171extern long join_session_keyring(const char *name);
172extern void key_change_session_keyring(struct callback_head *twork);
173
174extern struct work_struct key_gc_work;
175extern unsigned key_gc_delay;
176extern void keyring_gc(struct key *keyring, time64_t limit);
177extern void keyring_restriction_gc(struct key *keyring,
178				   struct key_type *dead_type);
179void key_set_expiry(struct key *key, time64_t expiry);
180extern void key_schedule_gc(time64_t gc_at);
181extern void key_schedule_gc_links(void);
182extern void key_gc_keytype(struct key_type *ktype);
183
184extern int key_task_permission(const key_ref_t key_ref,
185			       const struct cred *cred,
186			       enum key_need_perm need_perm);
187
188static inline void notify_key(struct key *key,
189			      enum key_notification_subtype subtype, u32 aux)
190{
191#ifdef CONFIG_KEY_NOTIFICATIONS
192	struct key_notification n = {
193		.watch.type	= WATCH_TYPE_KEY_NOTIFY,
194		.watch.subtype	= subtype,
195		.watch.info	= watch_sizeof(n),
196		.key_id		= key_serial(key),
197		.aux		= aux,
198	};
199
200	post_watch_notification(key->watchers, &n.watch, current_cred(),
201				n.key_id);
202#endif
203}
204
205/*
206 * Check to see whether permission is granted to use a key in the desired way.
207 */
208static inline int key_permission(const key_ref_t key_ref,
209				 enum key_need_perm need_perm)
210{
211	return key_task_permission(key_ref, current_cred(), need_perm);
212}
213
214extern struct key_type key_type_request_key_auth;
215extern struct key *request_key_auth_new(struct key *target,
216					const char *op,
217					const void *callout_info,
218					size_t callout_len,
219					struct key *dest_keyring);
220
221extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
222
223/*
224 * Determine whether a key is dead.
225 */
226static inline bool key_is_dead(const struct key *key, time64_t limit)
227{
228	time64_t expiry = key->expiry;
229
230	if (expiry != TIME64_MAX) {
231		if (!(key->type->flags & KEY_TYPE_INSTANT_REAP))
232			expiry += key_gc_delay;
233		if (expiry <= limit)
234			return true;
235	}
236
237	return
238		key->flags & ((1 << KEY_FLAG_DEAD) |
239			      (1 << KEY_FLAG_INVALIDATED)) ||
240		key->domain_tag->removed;
241}
242
243/*
244 * keyctl() functions
245 */
246extern long keyctl_get_keyring_ID(key_serial_t, int);
247extern long keyctl_join_session_keyring(const char __user *);
248extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
249extern long keyctl_revoke_key(key_serial_t);
250extern long keyctl_keyring_clear(key_serial_t);
251extern long keyctl_keyring_link(key_serial_t, key_serial_t);
252extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
253extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
254extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
255extern long keyctl_keyring_search(key_serial_t, const char __user *,
256				  const char __user *, key_serial_t);
257extern long keyctl_read_key(key_serial_t, char __user *, size_t);
258extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
259extern long keyctl_setperm_key(key_serial_t, key_perm_t);
260extern long keyctl_instantiate_key(key_serial_t, const void __user *,
261				   size_t, key_serial_t);
262extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
263extern long keyctl_set_reqkey_keyring(int);
264extern long keyctl_set_timeout(key_serial_t, unsigned);
265extern long keyctl_assume_authority(key_serial_t);
266extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
267				size_t buflen);
268extern long keyctl_session_to_parent(void);
269extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
270extern long keyctl_instantiate_key_iov(key_serial_t,
271				       const struct iovec __user *,
272				       unsigned, key_serial_t);
273extern long keyctl_invalidate_key(key_serial_t);
274extern long keyctl_restrict_keyring(key_serial_t id,
275				    const char __user *_type,
276				    const char __user *_restriction);
277#ifdef CONFIG_PERSISTENT_KEYRINGS
278extern long keyctl_get_persistent(uid_t, key_serial_t);
279extern unsigned persistent_keyring_expiry;
280#else
281static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
282{
283	return -EOPNOTSUPP;
284}
285#endif
286
287#ifdef CONFIG_KEY_DH_OPERATIONS
288extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
289			      size_t, struct keyctl_kdf_params __user *);
290extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
291				size_t, struct keyctl_kdf_params *);
292#ifdef CONFIG_COMPAT
293extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
294				char __user *buffer, size_t buflen,
295				struct compat_keyctl_kdf_params __user *kdf);
296#endif
297#define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
298#define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
299#else
300static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
301				     char __user *buffer, size_t buflen,
302				     struct keyctl_kdf_params __user *kdf)
303{
304	return -EOPNOTSUPP;
305}
306
307#ifdef CONFIG_COMPAT
308static inline long compat_keyctl_dh_compute(
309				struct keyctl_dh_params __user *params,
310				char __user *buffer, size_t buflen,
311				struct keyctl_kdf_params __user *kdf)
312{
313	return -EOPNOTSUPP;
314}
315#endif
316#endif
317
318#ifdef CONFIG_ASYMMETRIC_KEY_TYPE
319extern long keyctl_pkey_query(key_serial_t,
320			      const char __user *,
321			      struct keyctl_pkey_query __user *);
322
323extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
324			       const char __user *,
325			       const void __user *, const void __user *);
326
327extern long keyctl_pkey_e_d_s(int,
328			      const struct keyctl_pkey_params __user *,
329			      const char __user *,
330			      const void __user *, void __user *);
331#else
332static inline long keyctl_pkey_query(key_serial_t id,
333				     const char __user *_info,
334				     struct keyctl_pkey_query __user *_res)
335{
336	return -EOPNOTSUPP;
337}
338
339static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
340				      const char __user *_info,
341				      const void __user *_in,
342				      const void __user *_in2)
343{
344	return -EOPNOTSUPP;
345}
346
347static inline long keyctl_pkey_e_d_s(int op,
348				     const struct keyctl_pkey_params __user *params,
349				     const char __user *_info,
350				     const void __user *_in,
351				     void __user *_out)
352{
353	return -EOPNOTSUPP;
354}
355#endif
356
357extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
358
359#ifdef CONFIG_KEY_NOTIFICATIONS
360extern long keyctl_watch_key(key_serial_t, int, int);
361#else
362static inline long keyctl_watch_key(key_serial_t key_id, int watch_fd, int watch_id)
363{
364	return -EOPNOTSUPP;
365}
366#endif
367
368/*
369 * Debugging key validation
370 */
371#ifdef KEY_DEBUGGING
372extern void __key_check(const struct key *);
373
374static inline void key_check(const struct key *key)
375{
376	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
377		__key_check(key);
378}
379
380#else
381
382#define key_check(key) do {} while(0)
383
384#endif
385#endif /* _INTERNAL_H */
386