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