security/keys/internal.h

   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 #include <linux/task_work.h>
  18
  19 #ifdef __KDEBUG
  20 #define kenter(FMT, ...) \
  21         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  22 #define kleave(FMT, ...) \
  23         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  24 #define kdebug(FMT, ...) \
  25         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  26 #else
  27 #define kenter(FMT, ...) \
  28         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  29 #define kleave(FMT, ...) \
  30         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  31 #define kdebug(FMT, ...) \
  32         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  33 #endif
  34
  35 extern struct key_type key_type_dead;
  36 extern struct key_type key_type_user;
  37 extern struct key_type key_type_logon;
  38
  39 /*****************************************************************************/
  40 /*
  41  * Keep track of keys for a user.
  42  *
  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  *
  46  * We also keep track of keys under request from userspace for this UID here.
  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         kuid_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(kuid_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 kmem_cache *key_jar;
  80 extern struct rb_root key_serial_tree;
  81 extern spinlock_t key_serial_lock;
  82 extern struct mutex key_construction_mutex;
  83 extern wait_queue_head_t request_key_conswq;
  84
  85
  86 extern struct key_type *key_type_lookup(const char *type);
  87 extern void key_type_put(struct key_type *ktype);
  88
  89 extern int __key_link_begin(struct key *keyring,
  90                             const struct key_type *type,
  91                             const char *description,
  92                             unsigned long *_prealloc);
  93 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  94 extern void __key_link(struct key *keyring, struct key *key,
  95                        unsigned long *_prealloc);
  96 extern void __key_link_end(struct key *keyring,
  97                            struct key_type *type,
  98                            unsigned long prealloc);
  99
 100 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 101                                       const struct key_type *type,
 102                                       const char *description,
 103                                       key_perm_t perm);
 104
 105 extern struct key *keyring_search_instkey(struct key *keyring,
 106                                           key_serial_t target_id);
 107
 108 typedef int (*key_match_func_t)(const struct key *, const void *);
 109
 110 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 111                                     const struct cred *cred,
 112                                     struct key_type *type,
 113                                     const void *description,
 114                                     key_match_func_t match,
 115                                     bool no_state_check);
 116
 117 extern key_ref_t search_my_process_keyrings(struct key_type *type,
 118                                             const void *description,
 119                                             key_match_func_t match,
 120                                             bool no_state_check,
 121                                             const struct cred *cred);
 122 extern key_ref_t search_process_keyrings(struct key_type *type,
 123                                          const void *description,
 124                                          key_match_func_t match,
 125                                          const struct cred *cred);
 126
 127 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 128
 129 extern int install_user_keyrings(void);
 130 extern int install_thread_keyring_to_cred(struct cred *);
 131 extern int install_process_keyring_to_cred(struct cred *);
 132 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 133
 134 extern struct key *request_key_and_link(struct key_type *type,
 135                                         const char *description,
 136                                         const void *callout_info,
 137                                         size_t callout_len,
 138                                         void *aux,
 139                                         struct key *dest_keyring,
 140                                         unsigned long flags);
 141
 142 extern int lookup_user_key_possessed(const struct key *key, const void *target);
 143 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 144                                  key_perm_t perm);
 145 #define KEY_LOOKUP_CREATE       0x01
 146 #define KEY_LOOKUP_PARTIAL      0x02
 147 #define KEY_LOOKUP_FOR_UNLINK   0x04
 148
 149 extern long join_session_keyring(const char *name);
 150 extern void key_change_session_keyring(struct callback_head *twork);
 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 gc_at);
 156 extern void key_schedule_gc_links(void);
 157 extern void key_gc_keytype(struct key_type *ktype);
 158
 159 extern int key_task_permission(const key_ref_t key_ref,
 160                                const struct cred *cred,
 161                                key_perm_t perm);
 162
 163 /*
 164  * Check to see whether permission is granted to use a key in the desired way.
 165  */
 166 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 167 {
 168         return key_task_permission(key_ref, current_cred(), perm);
 169 }
 170
 171 /* required permissions */
 172 #define KEY_VIEW        0x01    /* require permission to view attributes */
 173 #define KEY_READ        0x02    /* require permission to read content */
 174 #define KEY_WRITE       0x04    /* require permission to update / modify */
 175 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 176 #define KEY_LINK        0x10    /* require permission to link */
 177 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 178 #define KEY_ALL         0x3f    /* all the above permissions */
 179
 180 /*
 181  * Authorisation record for request_key().
 182  */
 183 struct request_key_auth {
 184         struct key              *target_key;
 185         struct key              *dest_keyring;
 186         const struct cred       *cred;
 187         void                    *callout_info;
 188         size_t                  callout_len;
 189         pid_t                   pid;
 190 };
 191
 192 extern struct key_type key_type_request_key_auth;
 193 extern struct key *request_key_auth_new(struct key *target,
 194                                         const void *callout_info,
 195                                         size_t callout_len,
 196                                         struct key *dest_keyring);
 197
 198 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 199
 200 /*
 201  * Determine whether a key is dead.
 202  */
 203 static inline bool key_is_dead(struct key *key, time_t limit)
 204 {
 205         return
 206                 key->flags & ((1 << KEY_FLAG_DEAD) |
 207                               (1 << KEY_FLAG_INVALIDATED)) ||
 208                 (key->expiry > 0 && key->expiry <= limit);
 209 }
 210
 211 /*
 212  * keyctl() functions
 213  */
 214 extern long keyctl_get_keyring_ID(key_serial_t, int);
 215 extern long keyctl_join_session_keyring(const char __user *);
 216 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 217 extern long keyctl_revoke_key(key_serial_t);
 218 extern long keyctl_keyring_clear(key_serial_t);
 219 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 220 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 221 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 222 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 223                                   const char __user *, key_serial_t);
 224 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 225 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 226 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 227 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 228                                    size_t, key_serial_t);
 229 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 230 extern long keyctl_set_reqkey_keyring(int);
 231 extern long keyctl_set_timeout(key_serial_t, unsigned);
 232 extern long keyctl_assume_authority(key_serial_t);
 233 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 234                                 size_t buflen);
 235 extern long keyctl_session_to_parent(void);
 236 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 237 extern long keyctl_instantiate_key_iov(key_serial_t,
 238                                        const struct iovec __user *,
 239                                        unsigned, key_serial_t);
 240 extern long keyctl_invalidate_key(key_serial_t);
 241
 242 extern long keyctl_instantiate_key_common(key_serial_t,
 243                                           const struct iovec *,
 244                                           unsigned, size_t, key_serial_t);
 245
 246 /*
 247  * Debugging key validation
 248  */
 249 #ifdef KEY_DEBUGGING
 250 extern void __key_check(const struct key *);
 251
 252 static inline void key_check(const struct key *key)
 253 {
 254         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 255                 __key_check(key);
 256 }
 257
 258 #else
 259
 260 #define key_check(key) do {} while(0)
 261
 262 #endif
 263
 264 #endif /* _INTERNAL_H */