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/sched.h>
  16 #include <linux/key-type.h>
  17
  18 static inline __attribute__((format(printf, 1, 2)))
  19 void no_printk(const char *fmt, ...)
  20 {
  21 }
  22
  23 #ifdef __KDEBUG
  24 #define kenter(FMT, ...) \
  25         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  26 #define kleave(FMT, ...) \
  27         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  28 #define kdebug(FMT, ...) \
  29         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  30 #else
  31 #define kenter(FMT, ...) \
  32         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  33 #define kleave(FMT, ...) \
  34         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  35 #define kdebug(FMT, ...) \
  36         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  37 #endif
  38
  39 extern struct key_type key_type_user;
  40
  41 /*****************************************************************************/
  42 /*
  43  * keep track of keys for a user
  44  * - this needs to be separate to user_struct to avoid a refcount-loop
  45  *   (user_struct pins some keyrings which pin this struct)
  46  * - this also keeps track of keys under request from userspace for this UID
  47  */
  48 struct key_user {
  49         struct rb_node          node;
  50         struct mutex            cons_lock;      /* construction initiation lock */
  51         spinlock_t              lock;
  52         atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  53         atomic_t                nkeys;          /* number of keys */
  54         atomic_t                nikeys;         /* number of instantiated keys */
  55         uid_t                   uid;
  56         struct user_namespace   *user_ns;
  57         int                     qnkeys;         /* number of keys allocated to this user */
  58         int                     qnbytes;        /* number of bytes allocated to this user */
  59 };
  60
  61 extern struct rb_root   key_user_tree;
  62 extern spinlock_t       key_user_lock;
  63 extern struct key_user  root_key_user;
  64
  65 extern struct key_user *key_user_lookup(uid_t uid,
  66                                         struct user_namespace *user_ns);
  67 extern void key_user_put(struct key_user *user);
  68
  69 /*
  70  * key quota limits
  71  * - root has its own separate limits to everyone else
  72  */
  73 extern unsigned key_quota_root_maxkeys;
  74 extern unsigned key_quota_root_maxbytes;
  75 extern unsigned key_quota_maxkeys;
  76 extern unsigned key_quota_maxbytes;
  77
  78 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  79
  80
  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(struct key *keyring, struct key *key);
  91
  92 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
  93                                       const struct key_type *type,
  94                                       const char *description,
  95                                       key_perm_t perm);
  96
  97 extern struct key *keyring_search_instkey(struct key *keyring,
  98                                           key_serial_t target_id);
  99
 100 typedef int (*key_match_func_t)(const struct key *, const void *);
 101
 102 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 103                                     const struct cred *cred,
 104                                     struct key_type *type,
 105                                     const void *description,
 106                                     key_match_func_t match);
 107
 108 extern key_ref_t search_process_keyrings(struct key_type *type,
 109                                          const void *description,
 110                                          key_match_func_t match,
 111                                          const struct cred *cred);
 112
 113 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 114
 115 extern int install_user_keyrings(void);
 116 extern int install_thread_keyring_to_cred(struct cred *);
 117 extern int install_process_keyring_to_cred(struct cred *);
 118
 119 extern struct key *request_key_and_link(struct key_type *type,
 120                                         const char *description,
 121                                         const void *callout_info,
 122                                         size_t callout_len,
 123                                         void *aux,
 124                                         struct key *dest_keyring,
 125                                         unsigned long flags);
 126
 127 extern key_ref_t lookup_user_key(key_serial_t id, int create, int partial,
 128                                  key_perm_t perm);
 129
 130 extern long join_session_keyring(const char *name);
 131
 132 /*
 133  * check to see whether permission is granted to use a key in the desired way
 134  */
 135 extern int key_task_permission(const key_ref_t key_ref,
 136                                const struct cred *cred,
 137                                key_perm_t perm);
 138
 139 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 140 {
 141         return key_task_permission(key_ref, current_cred(), perm);
 142 }
 143
 144 /* required permissions */
 145 #define KEY_VIEW        0x01    /* require permission to view attributes */
 146 #define KEY_READ        0x02    /* require permission to read content */
 147 #define KEY_WRITE       0x04    /* require permission to update / modify */
 148 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 149 #define KEY_LINK        0x10    /* require permission to link */
 150 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 151 #define KEY_ALL         0x3f    /* all the above permissions */
 152
 153 /*
 154  * request_key authorisation
 155  */
 156 struct request_key_auth {
 157         struct key              *target_key;
 158         struct key              *dest_keyring;
 159         const struct cred       *cred;
 160         void                    *callout_info;
 161         size_t                  callout_len;
 162         pid_t                   pid;
 163 };
 164
 165 extern struct key_type key_type_request_key_auth;
 166 extern struct key *request_key_auth_new(struct key *target,
 167                                         const void *callout_info,
 168                                         size_t callout_len,
 169                                         struct key *dest_keyring);
 170
 171 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 172
 173 /*
 174  * keyctl functions
 175  */
 176 extern long keyctl_get_keyring_ID(key_serial_t, int);
 177 extern long keyctl_join_session_keyring(const char __user *);
 178 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 179 extern long keyctl_revoke_key(key_serial_t);
 180 extern long keyctl_keyring_clear(key_serial_t);
 181 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 182 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 183 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 184 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 185                                   const char __user *, key_serial_t);
 186 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 187 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 188 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 189 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 190                                    size_t, key_serial_t);
 191 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 192 extern long keyctl_set_reqkey_keyring(int);
 193 extern long keyctl_set_timeout(key_serial_t, unsigned);
 194 extern long keyctl_assume_authority(key_serial_t);
 195 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 196                                 size_t buflen);
 197
 198 /*
 199  * debugging key validation
 200  */
 201 #ifdef KEY_DEBUGGING
 202 extern void __key_check(const struct key *);
 203
 204 static inline void key_check(const struct key *key)
 205 {
 206         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 207                 __key_check(key);
 208 }
 209
 210 #else
 211
 212 #define key_check(key) do {} while(0)
 213
 214 #endif
 215
 216 #endif /* _INTERNAL_H */