xref: /openbmc/linux/security/keys/internal.h (revision 2fa49589)
1 /* Authentication token and access key management internal defs
2  *
3  * Copyright (C) 2003-5, 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #ifndef _INTERNAL_H
13 #define _INTERNAL_H
14 
15 #include <linux/sched.h>
16 #include <linux/wait_bit.h>
17 #include <linux/cred.h>
18 #include <linux/key-type.h>
19 #include <linux/task_work.h>
20 #include <linux/keyctl.h>
21 #include <linux/refcount.h>
22 #include <linux/compat.h>
23 
24 struct iovec;
25 
26 #ifdef __KDEBUG
27 #define kenter(FMT, ...) \
28 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
29 #define kleave(FMT, ...) \
30 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
31 #define kdebug(FMT, ...) \
32 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
33 #else
34 #define kenter(FMT, ...) \
35 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
36 #define kleave(FMT, ...) \
37 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
38 #define kdebug(FMT, ...) \
39 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
40 #endif
41 
42 extern struct key_type key_type_dead;
43 extern struct key_type key_type_user;
44 extern struct key_type key_type_logon;
45 
46 /*****************************************************************************/
47 /*
48  * Keep track of keys for a user.
49  *
50  * This needs to be separate to user_struct to avoid a refcount-loop
51  * (user_struct pins some keyrings which pin this struct).
52  *
53  * We also keep track of keys under request from userspace for this UID here.
54  */
55 struct key_user {
56 	struct rb_node		node;
57 	struct mutex		cons_lock;	/* construction initiation lock */
58 	spinlock_t		lock;
59 	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
60 	atomic_t		nkeys;		/* number of keys */
61 	atomic_t		nikeys;		/* number of instantiated keys */
62 	kuid_t			uid;
63 	int			qnkeys;		/* number of keys allocated to this user */
64 	int			qnbytes;	/* number of bytes allocated to this user */
65 };
66 
67 extern struct rb_root	key_user_tree;
68 extern spinlock_t	key_user_lock;
69 extern struct key_user	root_key_user;
70 
71 extern struct key_user *key_user_lookup(kuid_t uid);
72 extern void key_user_put(struct key_user *user);
73 
74 /*
75  * Key quota limits.
76  * - root has its own separate limits to everyone else
77  */
78 extern unsigned key_quota_root_maxkeys;
79 extern unsigned key_quota_root_maxbytes;
80 extern unsigned key_quota_maxkeys;
81 extern unsigned key_quota_maxbytes;
82 
83 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
84 
85 
86 extern struct kmem_cache *key_jar;
87 extern struct rb_root key_serial_tree;
88 extern spinlock_t key_serial_lock;
89 extern struct mutex key_construction_mutex;
90 extern wait_queue_head_t request_key_conswq;
91 
92 
93 extern struct key_type *key_type_lookup(const char *type);
94 extern void key_type_put(struct key_type *ktype);
95 
96 extern int __key_link_begin(struct key *keyring,
97 			    const struct keyring_index_key *index_key,
98 			    struct assoc_array_edit **_edit);
99 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
100 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
101 extern void __key_link_end(struct key *keyring,
102 			   const struct keyring_index_key *index_key,
103 			   struct assoc_array_edit *edit);
104 
105 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
106 				    const struct keyring_index_key *index_key);
107 
108 extern struct key *keyring_search_instkey(struct key *keyring,
109 					  key_serial_t target_id);
110 
111 extern int iterate_over_keyring(const struct key *keyring,
112 				int (*func)(const struct key *key, void *data),
113 				void *data);
114 
115 struct keyring_search_context {
116 	struct keyring_index_key index_key;
117 	const struct cred	*cred;
118 	struct key_match_data	match_data;
119 	unsigned		flags;
120 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
121 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
122 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
123 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
124 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
125 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
126 
127 	int (*iterator)(const void *object, void *iterator_data);
128 
129 	/* Internal stuff */
130 	int			skipped_ret;
131 	bool			possessed;
132 	key_ref_t		result;
133 	time64_t		now;
134 };
135 
136 extern bool key_default_cmp(const struct key *key,
137 			    const struct key_match_data *match_data);
138 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
139 				    struct keyring_search_context *ctx);
140 
141 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
142 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
143 
144 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
145 
146 extern int install_user_keyrings(void);
147 extern int install_thread_keyring_to_cred(struct cred *);
148 extern int install_process_keyring_to_cred(struct cred *);
149 extern int install_session_keyring_to_cred(struct cred *, struct key *);
150 
151 extern struct key *request_key_and_link(struct key_type *type,
152 					const char *description,
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 #define KEY_LOOKUP_CREATE	0x01
162 #define KEY_LOOKUP_PARTIAL	0x02
163 #define KEY_LOOKUP_FOR_UNLINK	0x04
164 
165 extern long join_session_keyring(const char *name);
166 extern void key_change_session_keyring(struct callback_head *twork);
167 
168 extern struct work_struct key_gc_work;
169 extern unsigned key_gc_delay;
170 extern void keyring_gc(struct key *keyring, time64_t limit);
171 extern void keyring_restriction_gc(struct key *keyring,
172 				   struct key_type *dead_type);
173 extern void key_schedule_gc(time64_t gc_at);
174 extern void key_schedule_gc_links(void);
175 extern void key_gc_keytype(struct key_type *ktype);
176 
177 extern int key_task_permission(const key_ref_t key_ref,
178 			       const struct cred *cred,
179 			       key_perm_t perm);
180 
181 /*
182  * Check to see whether permission is granted to use a key in the desired way.
183  */
184 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
185 {
186 	return key_task_permission(key_ref, current_cred(), perm);
187 }
188 
189 /*
190  * Authorisation record for request_key().
191  */
192 struct request_key_auth {
193 	struct key		*target_key;
194 	struct key		*dest_keyring;
195 	const struct cred	*cred;
196 	void			*callout_info;
197 	size_t			callout_len;
198 	pid_t			pid;
199 } __randomize_layout;
200 
201 extern struct key_type key_type_request_key_auth;
202 extern struct key *request_key_auth_new(struct key *target,
203 					const void *callout_info,
204 					size_t callout_len,
205 					struct key *dest_keyring);
206 
207 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
208 
209 /*
210  * Determine whether a key is dead.
211  */
212 static inline bool key_is_dead(const struct key *key, time64_t limit)
213 {
214 	return
215 		key->flags & ((1 << KEY_FLAG_DEAD) |
216 			      (1 << KEY_FLAG_INVALIDATED)) ||
217 		(key->expiry > 0 && key->expiry <= limit);
218 }
219 
220 /*
221  * keyctl() functions
222  */
223 extern long keyctl_get_keyring_ID(key_serial_t, int);
224 extern long keyctl_join_session_keyring(const char __user *);
225 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
226 extern long keyctl_revoke_key(key_serial_t);
227 extern long keyctl_keyring_clear(key_serial_t);
228 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
229 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
230 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
231 extern long keyctl_keyring_search(key_serial_t, const char __user *,
232 				  const char __user *, key_serial_t);
233 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
234 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
235 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
236 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
237 				   size_t, key_serial_t);
238 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
239 extern long keyctl_set_reqkey_keyring(int);
240 extern long keyctl_set_timeout(key_serial_t, unsigned);
241 extern long keyctl_assume_authority(key_serial_t);
242 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
243 				size_t buflen);
244 extern long keyctl_session_to_parent(void);
245 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
246 extern long keyctl_instantiate_key_iov(key_serial_t,
247 				       const struct iovec __user *,
248 				       unsigned, key_serial_t);
249 extern long keyctl_invalidate_key(key_serial_t);
250 
251 struct iov_iter;
252 extern long keyctl_instantiate_key_common(key_serial_t,
253 					  struct iov_iter *,
254 					  key_serial_t);
255 extern long keyctl_restrict_keyring(key_serial_t id,
256 				    const char __user *_type,
257 				    const char __user *_restriction);
258 #ifdef CONFIG_PERSISTENT_KEYRINGS
259 extern long keyctl_get_persistent(uid_t, key_serial_t);
260 extern unsigned persistent_keyring_expiry;
261 #else
262 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
263 {
264 	return -EOPNOTSUPP;
265 }
266 #endif
267 
268 #ifdef CONFIG_KEY_DH_OPERATIONS
269 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
270 			      size_t, struct keyctl_kdf_params __user *);
271 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
272 				size_t, struct keyctl_kdf_params *);
273 #ifdef CONFIG_KEYS_COMPAT
274 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
275 				char __user *buffer, size_t buflen,
276 				struct compat_keyctl_kdf_params __user *kdf);
277 #endif
278 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
279 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
280 #else
281 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
282 				     char __user *buffer, size_t buflen,
283 				     struct keyctl_kdf_params __user *kdf)
284 {
285 	return -EOPNOTSUPP;
286 }
287 
288 #ifdef CONFIG_KEYS_COMPAT
289 static inline long compat_keyctl_dh_compute(
290 				struct keyctl_dh_params __user *params,
291 				char __user *buffer, size_t buflen,
292 				struct keyctl_kdf_params __user *kdf)
293 {
294 	return -EOPNOTSUPP;
295 }
296 #endif
297 #endif
298 
299 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
300 extern long keyctl_pkey_query(key_serial_t,
301 			      const char __user *,
302 			      struct keyctl_pkey_query __user *);
303 
304 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
305 			       const char __user *,
306 			       const void __user *, const void __user *);
307 
308 extern long keyctl_pkey_e_d_s(int,
309 			      const struct keyctl_pkey_params __user *,
310 			      const char __user *,
311 			      const void __user *, void __user *);
312 #else
313 static inline long keyctl_pkey_query(key_serial_t id,
314 				     const char __user *_info,
315 				     struct keyctl_pkey_query __user *_res)
316 {
317 	return -EOPNOTSUPP;
318 }
319 
320 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
321 				      const char __user *_info,
322 				      const void __user *_in,
323 				      const void __user *_in2)
324 {
325 	return -EOPNOTSUPP;
326 }
327 
328 static inline long keyctl_pkey_e_d_s(int op,
329 				     const struct keyctl_pkey_params __user *params,
330 				     const char __user *_info,
331 				     const void __user *_in,
332 				     void __user *_out)
333 {
334 	return -EOPNOTSUPP;
335 }
336 #endif
337 
338 /*
339  * Debugging key validation
340  */
341 #ifdef KEY_DEBUGGING
342 extern void __key_check(const struct key *);
343 
344 static inline void key_check(const struct key *key)
345 {
346 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
347 		__key_check(key);
348 }
349 
350 #else
351 
352 #define key_check(key) do {} while(0)
353 
354 #endif
355 
356 #endif /* _INTERNAL_H */
357