security/keys/internal.h

   1 /* internal.h: 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/key-type.h>
  16
  17 static inline __attribute__((format(printf, 1, 2)))
  18 void no_printk(const char *fmt, ...)
  19 {
  20 }
  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 "xxx" FMT"yyy\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_user;
  39
  40 /*****************************************************************************/
  41 /*
  42  * keep track of keys for a user
  43  * - this needs to be separate to user_struct to avoid a refcount-loop
  44  *   (user_struct pins some keyrings which pin this struct)
  45  * - this also keeps track of keys under request from userspace for this UID
  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         int                     qnkeys;         /* number of keys allocated to this user */
  56         int                     qnbytes;        /* number of bytes allocated to this user */
  57 };
  58
  59 extern struct rb_root   key_user_tree;
  60 extern spinlock_t       key_user_lock;
  61 extern struct key_user  root_key_user;
  62
  63 extern struct key_user *key_user_lookup(uid_t uid);
  64 extern void key_user_put(struct key_user *user);
  65
  66 /*
  67  * key quota limits
  68  * - root has its own separate limits to everyone else
  69  */
  70 extern unsigned key_quota_root_maxkeys;
  71 extern unsigned key_quota_root_maxbytes;
  72 extern unsigned key_quota_maxkeys;
  73 extern unsigned key_quota_maxbytes;
  74
  75 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  76
  77
  78 extern struct rb_root key_serial_tree;
  79 extern spinlock_t key_serial_lock;
  80 extern struct mutex key_construction_mutex;
  81 extern wait_queue_head_t request_key_conswq;
  82
  83
  84 extern struct key_type *key_type_lookup(const char *type);
  85 extern void key_type_put(struct key_type *ktype);
  86
  87 extern int __key_link(struct key *keyring, struct key *key);
  88
  89 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
  90                                       const struct key_type *type,
  91                                       const char *description,
  92                                       key_perm_t perm);
  93
  94 extern struct key *keyring_search_instkey(struct key *keyring,
  95                                           key_serial_t target_id);
  96
  97 typedef int (*key_match_func_t)(const struct key *, const void *);
  98
  99 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 100                                     struct task_struct *tsk,
 101                                     struct key_type *type,
 102                                     const void *description,
 103                                     key_match_func_t match);
 104
 105 extern key_ref_t search_process_keyrings(struct key_type *type,
 106                                          const void *description,
 107                                          key_match_func_t match,
 108                                          struct task_struct *tsk);
 109
 110 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 111
 112 extern int install_user_keyrings(void);
 113 extern int install_thread_keyring(void);
 114 extern int install_process_keyring(void);
 115
 116 extern struct key *request_key_and_link(struct key_type *type,
 117                                         const char *description,
 118                                         const void *callout_info,
 119                                         size_t callout_len,
 120                                         void *aux,
 121                                         struct key *dest_keyring,
 122                                         unsigned long flags);
 123
 124 extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
 125                                  key_perm_t perm);
 126
 127 extern long join_session_keyring(const char *name);
 128
 129 /*
 130  * check to see whether permission is granted to use a key in the desired way
 131  */
 132 extern int key_task_permission(const key_ref_t key_ref,
 133                                struct task_struct *context,
 134                                key_perm_t perm);
 135
 136 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 137 {
 138         return key_task_permission(key_ref, current, perm);
 139 }
 140
 141 /* required permissions */
 142 #define KEY_VIEW        0x01    /* require permission to view attributes */
 143 #define KEY_READ        0x02    /* require permission to read content */
 144 #define KEY_WRITE       0x04    /* require permission to update / modify */
 145 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 146 #define KEY_LINK        0x10    /* require permission to link */
 147 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 148 #define KEY_ALL         0x3f    /* all the above permissions */
 149
 150 /*
 151  * request_key authorisation
 152  */
 153 struct request_key_auth {
 154         struct key              *target_key;
 155         struct key              *dest_keyring;
 156         struct task_struct      *context;
 157         void                    *callout_info;
 158         size_t                  callout_len;
 159         pid_t                   pid;
 160 };
 161
 162 extern struct key_type key_type_request_key_auth;
 163 extern struct key *request_key_auth_new(struct key *target,
 164                                         const void *callout_info,
 165                                         size_t callout_len,
 166                                         struct key *dest_keyring);
 167
 168 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 169
 170 /*
 171  * keyctl functions
 172  */
 173 extern long keyctl_get_keyring_ID(key_serial_t, int);
 174 extern long keyctl_join_session_keyring(const char __user *);
 175 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 176 extern long keyctl_revoke_key(key_serial_t);
 177 extern long keyctl_keyring_clear(key_serial_t);
 178 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 179 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 180 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 181 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 182                                   const char __user *, key_serial_t);
 183 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 184 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 185 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 186 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 187                                    size_t, key_serial_t);
 188 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 189 extern long keyctl_set_reqkey_keyring(int);
 190 extern long keyctl_set_timeout(key_serial_t, unsigned);
 191 extern long keyctl_assume_authority(key_serial_t);
 192 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 193                                 size_t buflen);
 194
 195 /*
 196  * debugging key validation
 197  */
 198 #ifdef KEY_DEBUGGING
 199 extern void __key_check(const struct key *);
 200
 201 static inline void key_check(const struct key *key)
 202 {
 203         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 204                 __key_check(key);
 205 }
 206
 207 #else
 208
 209 #define key_check(key) do {} while(0)
 210
 211 #endif
 212
 213 #endif /* _INTERNAL_H */