xref: /openbmc/linux/security/keys/internal.h (revision 8dde5715)
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 
20 struct iovec;
21 
22 #ifdef __KDEBUG
23 #define kenter(FMT, ...) \
24 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
25 #define kleave(FMT, ...) \
26 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
27 #define kdebug(FMT, ...) \
28 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
29 #else
30 #define kenter(FMT, ...) \
31 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
32 #define kleave(FMT, ...) \
33 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
34 #define kdebug(FMT, ...) \
35 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
36 #endif
37 
38 extern struct key_type key_type_dead;
39 extern struct key_type key_type_user;
40 extern struct key_type key_type_logon;
41 
42 /*****************************************************************************/
43 /*
44  * Keep track of keys for a user.
45  *
46  * This needs to be separate to user_struct to avoid a refcount-loop
47  * (user_struct pins some keyrings which pin this struct).
48  *
49  * We also keep track of keys under request from userspace for this UID here.
50  */
51 struct key_user {
52 	struct rb_node		node;
53 	struct mutex		cons_lock;	/* construction initiation lock */
54 	spinlock_t		lock;
55 	refcount_t		usage;		/* for accessing qnkeys & qnbytes */
56 	atomic_t		nkeys;		/* number of keys */
57 	atomic_t		nikeys;		/* number of instantiated keys */
58 	kuid_t			uid;
59 	int			qnkeys;		/* number of keys allocated to this user */
60 	int			qnbytes;	/* number of bytes allocated to this user */
61 };
62 
63 extern struct rb_root	key_user_tree;
64 extern spinlock_t	key_user_lock;
65 extern struct key_user	root_key_user;
66 
67 extern struct key_user *key_user_lookup(kuid_t uid);
68 extern void key_user_put(struct key_user *user);
69 
70 /*
71  * Key quota limits.
72  * - root has its own separate limits to everyone else
73  */
74 extern unsigned key_quota_root_maxkeys;
75 extern unsigned key_quota_root_maxbytes;
76 extern unsigned key_quota_maxkeys;
77 extern unsigned key_quota_maxbytes;
78 
79 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
80 
81 
82 extern struct kmem_cache *key_jar;
83 extern struct rb_root key_serial_tree;
84 extern spinlock_t key_serial_lock;
85 extern struct mutex key_construction_mutex;
86 extern wait_queue_head_t request_key_conswq;
87 
88 
89 extern struct key_type *key_type_lookup(const char *type);
90 extern void key_type_put(struct key_type *ktype);
91 
92 extern int __key_link_begin(struct key *keyring,
93 			    const struct keyring_index_key *index_key,
94 			    struct assoc_array_edit **_edit);
95 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
96 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
97 extern void __key_link_end(struct key *keyring,
98 			   const struct keyring_index_key *index_key,
99 			   struct assoc_array_edit *edit);
100 
101 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
102 				    const struct keyring_index_key *index_key);
103 
104 extern struct key *keyring_search_instkey(struct key *keyring,
105 					  key_serial_t target_id);
106 
107 extern int iterate_over_keyring(const struct key *keyring,
108 				int (*func)(const struct key *key, void *data),
109 				void *data);
110 
111 struct keyring_search_context {
112 	struct keyring_index_key index_key;
113 	const struct cred	*cred;
114 	struct key_match_data	match_data;
115 	unsigned		flags;
116 #define KEYRING_SEARCH_NO_STATE_CHECK	0x0001	/* Skip state checks */
117 #define KEYRING_SEARCH_DO_STATE_CHECK	0x0002	/* Override NO_STATE_CHECK */
118 #define KEYRING_SEARCH_NO_UPDATE_TIME	0x0004	/* Don't update times */
119 #define KEYRING_SEARCH_NO_CHECK_PERM	0x0008	/* Don't check permissions */
120 #define KEYRING_SEARCH_DETECT_TOO_DEEP	0x0010	/* Give an error on excessive depth */
121 #define KEYRING_SEARCH_SKIP_EXPIRED	0x0020	/* Ignore expired keys (intention to replace) */
122 
123 	int (*iterator)(const void *object, void *iterator_data);
124 
125 	/* Internal stuff */
126 	int			skipped_ret;
127 	bool			possessed;
128 	key_ref_t		result;
129 	time64_t		now;
130 };
131 
132 extern bool key_default_cmp(const struct key *key,
133 			    const struct key_match_data *match_data);
134 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
135 				    struct keyring_search_context *ctx);
136 
137 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
138 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
139 
140 extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
141 
142 extern int install_user_keyrings(void);
143 extern int install_thread_keyring_to_cred(struct cred *);
144 extern int install_process_keyring_to_cred(struct cred *);
145 extern int install_session_keyring_to_cred(struct cred *, struct key *);
146 
147 extern struct key *request_key_and_link(struct key_type *type,
148 					const char *description,
149 					const void *callout_info,
150 					size_t callout_len,
151 					void *aux,
152 					struct key *dest_keyring,
153 					unsigned long flags);
154 
155 extern bool lookup_user_key_possessed(const struct key *key,
156 				      const struct key_match_data *match_data);
157 #define KEY_LOOKUP_CREATE	0x01
158 #define KEY_LOOKUP_PARTIAL	0x02
159 #define KEY_LOOKUP_FOR_UNLINK	0x04
160 
161 extern long join_session_keyring(const char *name);
162 extern void key_change_session_keyring(struct callback_head *twork);
163 
164 extern struct work_struct key_gc_work;
165 extern unsigned key_gc_delay;
166 extern void keyring_gc(struct key *keyring, time64_t limit);
167 extern void keyring_restriction_gc(struct key *keyring,
168 				   struct key_type *dead_type);
169 extern void key_schedule_gc(time64_t gc_at);
170 extern void key_schedule_gc_links(void);
171 extern void key_gc_keytype(struct key_type *ktype);
172 
173 extern int key_task_permission(const key_ref_t key_ref,
174 			       const struct cred *cred,
175 			       key_perm_t perm);
176 
177 /*
178  * Check to see whether permission is granted to use a key in the desired way.
179  */
180 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
181 {
182 	return key_task_permission(key_ref, current_cred(), perm);
183 }
184 
185 extern struct key_type key_type_request_key_auth;
186 extern struct key *request_key_auth_new(struct key *target,
187 					const char *op,
188 					const void *callout_info,
189 					size_t callout_len,
190 					struct key *dest_keyring);
191 
192 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
193 
194 /*
195  * Determine whether a key is dead.
196  */
197 static inline bool key_is_dead(const struct key *key, time64_t limit)
198 {
199 	return
200 		key->flags & ((1 << KEY_FLAG_DEAD) |
201 			      (1 << KEY_FLAG_INVALIDATED)) ||
202 		(key->expiry > 0 && key->expiry <= limit);
203 }
204 
205 /*
206  * keyctl() functions
207  */
208 extern long keyctl_get_keyring_ID(key_serial_t, int);
209 extern long keyctl_join_session_keyring(const char __user *);
210 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
211 extern long keyctl_revoke_key(key_serial_t);
212 extern long keyctl_keyring_clear(key_serial_t);
213 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
214 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
215 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
216 extern long keyctl_keyring_search(key_serial_t, const char __user *,
217 				  const char __user *, key_serial_t);
218 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
219 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
220 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
221 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
222 				   size_t, key_serial_t);
223 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
224 extern long keyctl_set_reqkey_keyring(int);
225 extern long keyctl_set_timeout(key_serial_t, unsigned);
226 extern long keyctl_assume_authority(key_serial_t);
227 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
228 				size_t buflen);
229 extern long keyctl_session_to_parent(void);
230 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
231 extern long keyctl_instantiate_key_iov(key_serial_t,
232 				       const struct iovec __user *,
233 				       unsigned, key_serial_t);
234 extern long keyctl_invalidate_key(key_serial_t);
235 
236 struct iov_iter;
237 extern long keyctl_instantiate_key_common(key_serial_t,
238 					  struct iov_iter *,
239 					  key_serial_t);
240 extern long keyctl_restrict_keyring(key_serial_t id,
241 				    const char __user *_type,
242 				    const char __user *_restriction);
243 #ifdef CONFIG_PERSISTENT_KEYRINGS
244 extern long keyctl_get_persistent(uid_t, key_serial_t);
245 extern unsigned persistent_keyring_expiry;
246 #else
247 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
248 {
249 	return -EOPNOTSUPP;
250 }
251 #endif
252 
253 #ifdef CONFIG_KEY_DH_OPERATIONS
254 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
255 			      size_t, struct keyctl_kdf_params __user *);
256 extern long __keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
257 				size_t, struct keyctl_kdf_params *);
258 #ifdef CONFIG_KEYS_COMPAT
259 extern long compat_keyctl_dh_compute(struct keyctl_dh_params __user *params,
260 				char __user *buffer, size_t buflen,
261 				struct compat_keyctl_kdf_params __user *kdf);
262 #endif
263 #define KEYCTL_KDF_MAX_OUTPUT_LEN	1024	/* max length of KDF output */
264 #define KEYCTL_KDF_MAX_OI_LEN		64	/* max length of otherinfo */
265 #else
266 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
267 				     char __user *buffer, size_t buflen,
268 				     struct keyctl_kdf_params __user *kdf)
269 {
270 	return -EOPNOTSUPP;
271 }
272 
273 #ifdef CONFIG_KEYS_COMPAT
274 static inline long compat_keyctl_dh_compute(
275 				struct keyctl_dh_params __user *params,
276 				char __user *buffer, size_t buflen,
277 				struct keyctl_kdf_params __user *kdf)
278 {
279 	return -EOPNOTSUPP;
280 }
281 #endif
282 #endif
283 
284 #ifdef CONFIG_ASYMMETRIC_KEY_TYPE
285 extern long keyctl_pkey_query(key_serial_t,
286 			      const char __user *,
287 			      struct keyctl_pkey_query __user *);
288 
289 extern long keyctl_pkey_verify(const struct keyctl_pkey_params __user *,
290 			       const char __user *,
291 			       const void __user *, const void __user *);
292 
293 extern long keyctl_pkey_e_d_s(int,
294 			      const struct keyctl_pkey_params __user *,
295 			      const char __user *,
296 			      const void __user *, void __user *);
297 #else
298 static inline long keyctl_pkey_query(key_serial_t id,
299 				     const char __user *_info,
300 				     struct keyctl_pkey_query __user *_res)
301 {
302 	return -EOPNOTSUPP;
303 }
304 
305 static inline long keyctl_pkey_verify(const struct keyctl_pkey_params __user *params,
306 				      const char __user *_info,
307 				      const void __user *_in,
308 				      const void __user *_in2)
309 {
310 	return -EOPNOTSUPP;
311 }
312 
313 static inline long keyctl_pkey_e_d_s(int op,
314 				     const struct keyctl_pkey_params __user *params,
315 				     const char __user *_info,
316 				     const void __user *_in,
317 				     void __user *_out)
318 {
319 	return -EOPNOTSUPP;
320 }
321 #endif
322 
323 /*
324  * Debugging key validation
325  */
326 #ifdef KEY_DEBUGGING
327 extern void __key_check(const struct key *);
328 
329 static inline void key_check(const struct key *key)
330 {
331 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
332 		__key_check(key);
333 }
334 
335 #else
336 
337 #define key_check(key) do {} while(0)
338 
339 #endif
340 
341 #endif /* _INTERNAL_H */
342