xref: /openbmc/linux/security/keys/internal.h (revision e72e8bf1)
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/compat.h>
19 #include <linux/mm.h>
20 #include <linux/vmalloc.h>
21 
22 struct iovec;
23 
24 #ifdef __KDEBUG
25 #define kenter(FMT, ...) \
26 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
27 #define kleave(FMT, ...) \
28 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
29 #define kdebug(FMT, ...) \
30 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
31 #else
32 #define kenter(FMT, ...) \
33 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
34 #define kleave(FMT, ...) \
35 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
36 #define kdebug(FMT, ...) \
37 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
38 #endif
39 
40 extern struct key_type key_type_dead;
41 extern struct key_type key_type_user;
42 extern struct key_type key_type_logon;
43 
44 /*****************************************************************************/
45 /*
46  * Keep track of keys for a user.
47  *
48  * This needs to be separate to user_struct to avoid a refcount-loop
49  * (user_struct pins some keyrings which pin this struct).
50  *
51  * We also keep track of keys under request from userspace for this UID here.
52  */
53 struct key_user {
54 	struct rb_node		node;
55 	struct mutex		cons_lock;	/* construction initiation lock */
56 	spinlock_t		lock;
57 	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
58 	atomic_t		nkeys;		/* number of keys */
59 	atomic_t		nikeys;		/* number of instantiated keys */
60 	kuid_t			uid;
61 	int			qnkeys;		/* number of keys allocated to this user */
62 	int			qnbytes;	/* number of bytes allocated to this user */
63 };
64 
65 extern struct rb_root	key_user_tree;
66 extern spinlock_t	key_user_lock;
67 extern struct key_user	root_key_user;
68 
69 extern struct key_user *key_user_lookup(kuid_t uid);
70 extern void key_user_put(struct key_user *user);
71 
72 /*
73  * Key quota limits.
74  * - root has its own separate limits to everyone else
75  */
76 extern unsigned key_quota_root_maxkeys;
77 extern unsigned key_quota_root_maxbytes;
78 extern unsigned key_quota_maxkeys;
79 extern unsigned key_quota_maxbytes;
80 
81 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
82 
83 
84 extern struct kmem_cache *key_jar;
85 extern struct rb_root key_serial_tree;
86 extern spinlock_t key_serial_lock;
87 extern struct mutex key_construction_mutex;
88 extern wait_queue_head_t request_key_conswq;
89 
90 extern void key_set_index_key(struct keyring_index_key *index_key);
91 extern struct key_type *key_type_lookup(const char *type);
92 extern void key_type_put(struct key_type *ktype);
93 
94 extern int __key_link_lock(struct key *keyring,
95 			   const struct keyring_index_key *index_key);
96 extern int __key_move_lock(struct key *l_keyring, struct key *u_keyring,
97 			   const struct keyring_index_key *index_key);
98 extern int __key_link_begin(struct key *keyring,
99 			    const struct keyring_index_key *index_key,
100 			    struct assoc_array_edit **_edit);
101 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
102 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
103 extern void __key_link_end(struct key *keyring,
104 			   const struct keyring_index_key *index_key,
105 			   struct assoc_array_edit *edit);
106 
107 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
108 				    const struct keyring_index_key *index_key);
109 
110 extern struct key *keyring_search_instkey(struct key *keyring,
111 					  key_serial_t target_id);
112 
113 extern int iterate_over_keyring(const struct key *keyring,
114 				int (*func)(const struct key *key, void *data),
115 				void *data);
116 
117 struct keyring_search_context {
118 	struct keyring_index_key index_key;
119 	const struct cred	*cred;
120 	struct key_match_data	match_data;
121 	unsigned		flags;
122 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
123 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
124 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
125 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
126 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
127 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
128 #define KEYRING_SEARCH_RECURSE		0x0040	/* Search child keyrings also */
129 
130 	int (*iterator)(const void *object, void *iterator_data);
131 
132 	/* Internal stuff */
133 	int			skipped_ret;
134 	bool			possessed;
135 	key_ref_t		result;
136 	time64_t		now;
137 };
138 
139 extern bool key_default_cmp(const struct key *key,
140 			    const struct key_match_data *match_data);
141 extern key_ref_t keyring_search_rcu(key_ref_t keyring_ref,
142 				    struct keyring_search_context *ctx);
143 
144 extern key_ref_t search_cred_keyrings_rcu(struct keyring_search_context *ctx);
145 extern key_ref_t search_process_keyrings_rcu(struct keyring_search_context *ctx);
146 
147 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
148 
149 extern int look_up_user_keyrings(struct key **, struct key **);
150 extern struct key *get_user_session_keyring_rcu(const struct cred *);
151 extern int install_thread_keyring_to_cred(struct cred *);
152 extern int install_process_keyring_to_cred(struct cred *);
153 extern int install_session_keyring_to_cred(struct cred *, struct key *);
154 
155 extern struct key *request_key_and_link(struct key_type *type,
156 					const char *description,
157 					struct key_tag *domain_tag,
158 					const void *callout_info,
159 					size_t callout_len,
160 					void *aux,
161 					struct key *dest_keyring,
162 					unsigned long flags);
163 
164 extern bool lookup_user_key_possessed(const struct key *key,
165 				      const struct key_match_data *match_data);
166 #define KEY_LOOKUP_CREATE	0x01
167 #define KEY_LOOKUP_PARTIAL	0x02
168 #define KEY_LOOKUP_FOR_UNLINK	0x04
169 
170 extern long join_session_keyring(const char *name);
171 extern void key_change_session_keyring(struct callback_head *twork);
172 
173 extern struct work_struct key_gc_work;
174 extern unsigned key_gc_delay;
175 extern void keyring_gc(struct key *keyring, time64_t limit);
176 extern void keyring_restriction_gc(struct key *keyring,
177 				   struct key_type *dead_type);
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 			       key_perm_t perm);
185 
186 /*
187  * Check to see whether permission is granted to use a key in the desired way.
188  */
189 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
190 {
191 	return key_task_permission(key_ref, current_cred(), perm);
192 }
193 
194 extern struct key_type key_type_request_key_auth;
195 extern struct key *request_key_auth_new(struct key *target,
196 					const char *op,
197 					const void *callout_info,
198 					size_t callout_len,
199 					struct key *dest_keyring);
200 
201 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
202 
203 /*
204  * Determine whether a key is dead.
205  */
206 static inline bool key_is_dead(const struct key *key, time64_t limit)
207 {
208 	return
209 		key->flags & ((1 << KEY_FLAG_DEAD) |
210 			      (1 << KEY_FLAG_INVALIDATED)) ||
211 		(key->expiry > 0 && key->expiry <= limit) ||
212 		key->domain_tag->removed;
213 }
214 
215 /*
216  * keyctl() functions
217  */
218 extern long keyctl_get_keyring_ID(key_serial_t, int);
219 extern long keyctl_join_session_keyring(const char __user *);
220 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
221 extern long keyctl_revoke_key(key_serial_t);
222 extern long keyctl_keyring_clear(key_serial_t);
223 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
224 extern long keyctl_keyring_move(key_serial_t, key_serial_t, key_serial_t, unsigned int);
225 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
226 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
227 extern long keyctl_keyring_search(key_serial_t, const char __user *,
228 				  const char __user *, key_serial_t);
229 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
230 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
231 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
232 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
233 				   size_t, key_serial_t);
234 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
235 extern long keyctl_set_reqkey_keyring(int);
236 extern long keyctl_set_timeout(key_serial_t, unsigned);
237 extern long keyctl_assume_authority(key_serial_t);
238 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
239 				size_t buflen);
240 extern long keyctl_session_to_parent(void);
241 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
242 extern long keyctl_instantiate_key_iov(key_serial_t,
243 				       const struct iovec __user *,
244 				       unsigned, key_serial_t);
245 extern long keyctl_invalidate_key(key_serial_t);
246 
247 struct iov_iter;
248 extern long keyctl_instantiate_key_common(key_serial_t,
249 					  struct iov_iter *,
250 					  key_serial_t);
251 extern long keyctl_restrict_keyring(key_serial_t id,
252 				    const char __user *_type,
253 				    const char __user *_restriction);
254 #ifdef CONFIG_PERSISTENT_KEYRINGS
255 extern long keyctl_get_persistent(uid_t, key_serial_t);
256 extern unsigned persistent_keyring_expiry;
257 #else
258 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
259 {
260 	return -EOPNOTSUPP;
261 }
262 #endif
263 
264 #ifdef CONFIG_KEY_DH_OPERATIONS
265 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
266 			      size_t, struct keyctl_kdf_params __user *);
267 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
268 				size_t, struct keyctl_kdf_params *);
269 #ifdef CONFIG_COMPAT
270 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
271 				char __user *buffer, size_t buflen,
272 				struct compat_keyctl_kdf_params __user *kdf);
273 #endif
274 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
275 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
276 #else
277 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
278 				     char __user *buffer, size_t buflen,
279 				     struct keyctl_kdf_params __user *kdf)
280 {
281 	return -EOPNOTSUPP;
282 }
283 
284 #ifdef CONFIG_COMPAT
285 static inline long compat_keyctl_dh_compute(
286 				struct keyctl_dh_params __user *params,
287 				char __user *buffer, size_t buflen,
288 				struct keyctl_kdf_params __user *kdf)
289 {
290 	return -EOPNOTSUPP;
291 }
292 #endif
293 #endif
294 
295 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
296 extern long keyctl_pkey_query(key_serial_t,
297 			      const char __user *,
298 			      struct keyctl_pkey_query __user *);
299 
300 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
301 			       const char __user *,
302 			       const void __user *, const void __user *);
303 
304 extern long keyctl_pkey_e_d_s(int,
305 			      const struct keyctl_pkey_params __user *,
306 			      const char __user *,
307 			      const void __user *, void __user *);
308 #else
309 static inline long keyctl_pkey_query(key_serial_t id,
310 				     const char __user *_info,
311 				     struct keyctl_pkey_query __user *_res)
312 {
313 	return -EOPNOTSUPP;
314 }
315 
316 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
317 				      const char __user *_info,
318 				      const void __user *_in,
319 				      const void __user *_in2)
320 {
321 	return -EOPNOTSUPP;
322 }
323 
324 static inline long keyctl_pkey_e_d_s(int op,
325 				     const struct keyctl_pkey_params __user *params,
326 				     const char __user *_info,
327 				     const void __user *_in,
328 				     void __user *_out)
329 {
330 	return -EOPNOTSUPP;
331 }
332 #endif
333 
334 extern long keyctl_capabilities(unsigned char __user *_buffer, size_t buflen);
335 
336 /*
337  * Debugging key validation
338  */
339 #ifdef KEY_DEBUGGING
340 extern void __key_check(const struct key *);
341 
342 static inline void key_check(const struct key *key)
343 {
344 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
345 		__key_check(key);
346 }
347 
348 #else
349 
350 #define key_check(key) do {} while(0)
351 
352 #endif
353 
354 /*
355  * Helper function to clear and free a kvmalloc'ed memory object.
356  */
357 static inline void __kvzfree(const void *addr, size_t len)
358 {
359 	if (addr) {
360 		memset((void *)addr, 0, len);
361 		kvfree(addr);
362 	}
363 }
364 #endif /* _INTERNAL_H */
365