xref: /openbmc/linux/security/keys/internal.h (revision 63dc02bd)
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/key-type.h>
17 
18 #ifdef __KDEBUG
19 #define kenter(FMT, ...) \
20 	printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
21 #define kleave(FMT, ...) \
22 	printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
23 #define kdebug(FMT, ...) \
24 	printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
25 #else
26 #define kenter(FMT, ...) \
27 	no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
28 #define kleave(FMT, ...) \
29 	no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
30 #define kdebug(FMT, ...) \
31 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
32 #endif
33 
34 extern struct key_type key_type_dead;
35 extern struct key_type key_type_user;
36 extern struct key_type key_type_logon;
37 
38 /*****************************************************************************/
39 /*
40  * Keep track of keys for a user.
41  *
42  * This needs to be separate to user_struct to avoid a refcount-loop
43  * (user_struct pins some keyrings which pin this struct).
44  *
45  * We also keep track of keys under request from userspace for this UID here.
46  */
47 struct key_user {
48 	struct rb_node		node;
49 	struct mutex		cons_lock;	/* construction initiation lock */
50 	spinlock_t		lock;
51 	atomic_t		usage;		/* for accessing qnkeys & qnbytes */
52 	atomic_t		nkeys;		/* number of keys */
53 	atomic_t		nikeys;		/* number of instantiated keys */
54 	uid_t			uid;
55 	struct user_namespace	*user_ns;
56 	int			qnkeys;		/* number of keys allocated to this user */
57 	int			qnbytes;	/* number of bytes allocated to this user */
58 };
59 
60 extern struct rb_root	key_user_tree;
61 extern spinlock_t	key_user_lock;
62 extern struct key_user	root_key_user;
63 
64 extern struct key_user *key_user_lookup(uid_t uid,
65 					struct user_namespace *user_ns);
66 extern void key_user_put(struct key_user *user);
67 
68 /*
69  * Key quota limits.
70  * - root has its own separate limits to everyone else
71  */
72 extern unsigned key_quota_root_maxkeys;
73 extern unsigned key_quota_root_maxbytes;
74 extern unsigned key_quota_maxkeys;
75 extern unsigned key_quota_maxbytes;
76 
77 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
78 
79 
80 extern struct kmem_cache *key_jar;
81 extern struct rb_root key_serial_tree;
82 extern spinlock_t key_serial_lock;
83 extern struct mutex key_construction_mutex;
84 extern wait_queue_head_t request_key_conswq;
85 
86 
87 extern struct key_type *key_type_lookup(const char *type);
88 extern void key_type_put(struct key_type *ktype);
89 
90 extern int __key_link_begin(struct key *keyring,
91 			    const struct key_type *type,
92 			    const char *description,
93 			    unsigned long *_prealloc);
94 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
95 extern void __key_link(struct key *keyring, struct key *key,
96 		       unsigned long *_prealloc);
97 extern void __key_link_end(struct key *keyring,
98 			   struct key_type *type,
99 			   unsigned long prealloc);
100 
101 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
102 				      const struct key_type *type,
103 				      const char *description,
104 				      key_perm_t perm);
105 
106 extern struct key *keyring_search_instkey(struct key *keyring,
107 					  key_serial_t target_id);
108 
109 typedef int (*key_match_func_t)(const struct key *, const void *);
110 
111 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
112 				    const struct cred *cred,
113 				    struct key_type *type,
114 				    const void *description,
115 				    key_match_func_t match,
116 				    bool no_state_check);
117 
118 extern key_ref_t search_my_process_keyrings(struct key_type *type,
119 					    const void *description,
120 					    key_match_func_t match,
121 					    bool no_state_check,
122 					    const struct cred *cred);
123 extern key_ref_t search_process_keyrings(struct key_type *type,
124 					 const void *description,
125 					 key_match_func_t match,
126 					 const struct cred *cred);
127 
128 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
129 
130 extern int install_user_keyrings(void);
131 extern int install_thread_keyring_to_cred(struct cred *);
132 extern int install_process_keyring_to_cred(struct cred *);
133 extern int install_session_keyring_to_cred(struct cred *, struct key *);
134 
135 extern struct key *request_key_and_link(struct key_type *type,
136 					const char *description,
137 					const void *callout_info,
138 					size_t callout_len,
139 					void *aux,
140 					struct key *dest_keyring,
141 					unsigned long flags);
142 
143 extern int lookup_user_key_possessed(const struct key *key, const void *target);
144 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
145 				 key_perm_t perm);
146 #define KEY_LOOKUP_CREATE	0x01
147 #define KEY_LOOKUP_PARTIAL	0x02
148 #define KEY_LOOKUP_FOR_UNLINK	0x04
149 
150 extern long join_session_keyring(const char *name);
151 
152 extern struct work_struct key_gc_work;
153 extern unsigned key_gc_delay;
154 extern void keyring_gc(struct key *keyring, time_t limit);
155 extern void key_schedule_gc(time_t expiry_at);
156 extern void key_gc_keytype(struct key_type *ktype);
157 
158 extern int key_task_permission(const key_ref_t key_ref,
159 			       const struct cred *cred,
160 			       key_perm_t perm);
161 
162 /*
163  * Check to see whether permission is granted to use a key in the desired way.
164  */
165 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
166 {
167 	return key_task_permission(key_ref, current_cred(), perm);
168 }
169 
170 /* required permissions */
171 #define	KEY_VIEW	0x01	/* require permission to view attributes */
172 #define	KEY_READ	0x02	/* require permission to read content */
173 #define	KEY_WRITE	0x04	/* require permission to update / modify */
174 #define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
175 #define	KEY_LINK	0x10	/* require permission to link */
176 #define	KEY_SETATTR	0x20	/* require permission to change attributes */
177 #define	KEY_ALL		0x3f	/* all the above permissions */
178 
179 /*
180  * Authorisation record for request_key().
181  */
182 struct request_key_auth {
183 	struct key		*target_key;
184 	struct key		*dest_keyring;
185 	const struct cred	*cred;
186 	void			*callout_info;
187 	size_t			callout_len;
188 	pid_t			pid;
189 };
190 
191 extern struct key_type key_type_request_key_auth;
192 extern struct key *request_key_auth_new(struct key *target,
193 					const void *callout_info,
194 					size_t callout_len,
195 					struct key *dest_keyring);
196 
197 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
198 
199 /*
200  * keyctl() functions
201  */
202 extern long keyctl_get_keyring_ID(key_serial_t, int);
203 extern long keyctl_join_session_keyring(const char __user *);
204 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
205 extern long keyctl_revoke_key(key_serial_t);
206 extern long keyctl_keyring_clear(key_serial_t);
207 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
208 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
209 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
210 extern long keyctl_keyring_search(key_serial_t, const char __user *,
211 				  const char __user *, key_serial_t);
212 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
213 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
214 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
215 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
216 				   size_t, key_serial_t);
217 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
218 extern long keyctl_set_reqkey_keyring(int);
219 extern long keyctl_set_timeout(key_serial_t, unsigned);
220 extern long keyctl_assume_authority(key_serial_t);
221 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
222 				size_t buflen);
223 extern long keyctl_session_to_parent(void);
224 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
225 extern long keyctl_instantiate_key_iov(key_serial_t,
226 				       const struct iovec __user *,
227 				       unsigned, key_serial_t);
228 
229 extern long keyctl_instantiate_key_common(key_serial_t,
230 					  const struct iovec __user *,
231 					  unsigned, size_t, key_serial_t);
232 
233 /*
234  * Debugging key validation
235  */
236 #ifdef KEY_DEBUGGING
237 extern void __key_check(const struct key *);
238 
239 static inline void key_check(const struct key *key)
240 {
241 	if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
242 		__key_check(key);
243 }
244 
245 #else
246 
247 #define key_check(key) do {} while(0)
248 
249 #endif
250 
251 #endif /* _INTERNAL_H */
252