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/cred.h>
  17 #include <linux/key-type.h>
  18 #include <linux/task_work.h>
  19 #include <linux/keyctl.h>
  20
  21 struct iovec;
  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_dead;
  40 extern struct key_type key_type_user;
  41 extern struct key_type key_type_logon;
  42
  43 /*****************************************************************************/
  44 /*
  45  * Keep track of keys for a user.
  46  *
  47  * This needs to be separate to user_struct to avoid a refcount-loop
  48  * (user_struct pins some keyrings which pin this struct).
  49  *
  50  * We also keep track of keys under request from userspace for this UID here.
  51  */
  52 struct key_user {
  53         struct rb_node          node;
  54         struct mutex            cons_lock;      /* construction initiation lock */
  55         spinlock_t              lock;
  56         atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  57         atomic_t                nkeys;          /* number of keys */
  58         atomic_t                nikeys;         /* number of instantiated keys */
  59         kuid_t                  uid;
  60         int                     qnkeys;         /* number of keys allocated to this user */
  61         int                     qnbytes;        /* number of bytes allocated to this user */
  62 };
  63
  64 extern struct rb_root   key_user_tree;
  65 extern spinlock_t       key_user_lock;
  66 extern struct key_user  root_key_user;
  67
  68 extern struct key_user *key_user_lookup(kuid_t uid);
  69 extern void key_user_put(struct key_user *user);
  70
  71 /*
  72  * Key quota limits.
  73  * - root has its own separate limits to everyone else
  74  */
  75 extern unsigned key_quota_root_maxkeys;
  76 extern unsigned key_quota_root_maxbytes;
  77 extern unsigned key_quota_maxkeys;
  78 extern unsigned key_quota_maxbytes;
  79
  80 #define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  81
  82
  83 extern struct kmem_cache *key_jar;
  84 extern struct rb_root key_serial_tree;
  85 extern spinlock_t key_serial_lock;
  86 extern struct mutex key_construction_mutex;
  87 extern wait_queue_head_t request_key_conswq;
  88
  89
  90 extern struct key_type *key_type_lookup(const char *type);
  91 extern void key_type_put(struct key_type *ktype);
  92
  93 extern int __key_link_begin(struct key *keyring,
  94                             const struct keyring_index_key *index_key,
  95                             struct assoc_array_edit **_edit);
  96 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  97 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
  98 extern void __key_link_end(struct key *keyring,
  99                            const struct keyring_index_key *index_key,
 100                            struct assoc_array_edit *edit);
 101
 102 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 103                                     const struct keyring_index_key *index_key);
 104
 105 extern struct key *keyring_search_instkey(struct key *keyring,
 106                                           key_serial_t target_id);
 107
 108 extern int iterate_over_keyring(const struct key *keyring,
 109                                 int (*func)(const struct key *key, void *data),
 110                                 void *data);
 111
 112 struct keyring_search_context {
 113         struct keyring_index_key index_key;
 114         const struct cred       *cred;
 115         struct key_match_data   match_data;
 116         unsigned                flags;
 117 #define KEYRING_SEARCH_NO_STATE_CHECK   0x0001  /* Skip state checks */
 118 #define KEYRING_SEARCH_DO_STATE_CHECK   0x0002  /* Override NO_STATE_CHECK */
 119 #define KEYRING_SEARCH_NO_UPDATE_TIME   0x0004  /* Don't update times */
 120 #define KEYRING_SEARCH_NO_CHECK_PERM    0x0008  /* Don't check permissions */
 121 #define KEYRING_SEARCH_DETECT_TOO_DEEP  0x0010  /* Give an error on excessive depth */
 122 #define KEYRING_SEARCH_SKIP_EXPIRED     0x0020  /* Ignore expired keys (intention to replace) */
 123
 124         int (*iterator)(const void *object, void *iterator_data);
 125
 126         /* Internal stuff */
 127         int                     skipped_ret;
 128         bool                    possessed;
 129         key_ref_t               result;
 130         struct timespec         now;
 131 };
 132
 133 extern bool key_default_cmp(const struct key *key,
 134                             const struct key_match_data *match_data);
 135 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 136                                     struct keyring_search_context *ctx);
 137
 138 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
 139 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
 140
 141 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 142
 143 extern int install_user_keyrings(void);
 144 extern int install_thread_keyring_to_cred(struct cred *);
 145 extern int install_process_keyring_to_cred(struct cred *);
 146 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 147
 148 extern struct key *request_key_and_link(struct key_type *type,
 149                                         const char *description,
 150                                         const void *callout_info,
 151                                         size_t callout_len,
 152                                         void *aux,
 153                                         struct key *dest_keyring,
 154                                         unsigned long flags);
 155
 156 extern bool lookup_user_key_possessed(const struct key *key,
 157                                       const struct key_match_data *match_data);
 158 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 159                                  key_perm_t perm);
 160 #define KEY_LOOKUP_CREATE       0x01
 161 #define KEY_LOOKUP_PARTIAL      0x02
 162 #define KEY_LOOKUP_FOR_UNLINK   0x04
 163
 164 extern long join_session_keyring(const char *name);
 165 extern void key_change_session_keyring(struct callback_head *twork);
 166
 167 extern struct work_struct key_gc_work;
 168 extern unsigned key_gc_delay;
 169 extern void keyring_gc(struct key *keyring, time_t limit);
 170 extern void key_schedule_gc(time_t gc_at);
 171 extern void key_schedule_gc_links(void);
 172 extern void key_gc_keytype(struct key_type *ktype);
 173
 174 extern int key_task_permission(const key_ref_t key_ref,
 175                                const struct cred *cred,
 176                                key_perm_t perm);
 177
 178 /*
 179  * Check to see whether permission is granted to use a key in the desired way.
 180  */
 181 static inline int key_permission(const key_ref_t key_ref, unsigned perm)
 182 {
 183         return key_task_permission(key_ref, current_cred(), perm);
 184 }
 185
 186 /*
 187  * Authorisation record for request_key().
 188  */
 189 struct request_key_auth {
 190         struct key              *target_key;
 191         struct key              *dest_keyring;
 192         const struct cred       *cred;
 193         void                    *callout_info;
 194         size_t                  callout_len;
 195         pid_t                   pid;
 196 };
 197
 198 extern struct key_type key_type_request_key_auth;
 199 extern struct key *request_key_auth_new(struct key *target,
 200                                         const void *callout_info,
 201                                         size_t callout_len,
 202                                         struct key *dest_keyring);
 203
 204 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 205
 206 /*
 207  * Determine whether a key is dead.
 208  */
 209 static inline bool key_is_dead(const struct key *key, time_t limit)
 210 {
 211         return
 212                 key->flags & ((1 << KEY_FLAG_DEAD) |
 213                               (1 << KEY_FLAG_INVALIDATED)) ||
 214                 (key->expiry > 0 && key->expiry <= limit);
 215 }
 216
 217 /*
 218  * keyctl() functions
 219  */
 220 extern long keyctl_get_keyring_ID(key_serial_t, int);
 221 extern long keyctl_join_session_keyring(const char __user *);
 222 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 223 extern long keyctl_revoke_key(key_serial_t);
 224 extern long keyctl_keyring_clear(key_serial_t);
 225 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 226 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 227 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 228 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 229                                   const char __user *, key_serial_t);
 230 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 231 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 232 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 233 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 234                                    size_t, key_serial_t);
 235 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 236 extern long keyctl_set_reqkey_keyring(int);
 237 extern long keyctl_set_timeout(key_serial_t, unsigned);
 238 extern long keyctl_assume_authority(key_serial_t);
 239 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 240                                 size_t buflen);
 241 extern long keyctl_session_to_parent(void);
 242 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 243 extern long keyctl_instantiate_key_iov(key_serial_t,
 244                                        const struct iovec __user *,
 245                                        unsigned, key_serial_t);
 246 extern long keyctl_invalidate_key(key_serial_t);
 247
 248 struct iov_iter;
 249 extern long keyctl_instantiate_key_common(key_serial_t,
 250                                           struct iov_iter *,
 251                                           key_serial_t);
 252 #ifdef CONFIG_PERSISTENT_KEYRINGS
 253 extern long keyctl_get_persistent(uid_t, key_serial_t);
 254 extern unsigned persistent_keyring_expiry;
 255 #else
 256 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 257 {
 258         return -EOPNOTSUPP;
 259 }
 260 #endif
 261
 262 #ifdef CONFIG_KEY_DH_OPERATIONS
 263 extern long keyctl_dh_compute(struct keyctl_dh_params __user *, char __user *,
 264                               size_t, void __user *);
 265 #else
 266 static inline long keyctl_dh_compute(struct keyctl_dh_params __user *params,
 267                                      char __user *buffer, size_t buflen,
 268                                      void __user *reserved)
 269 {
 270         return -EOPNOTSUPP;
 271 }
 272 #endif
 273
 274 /*
 275  * Debugging key validation
 276  */
 277 #ifdef KEY_DEBUGGING
 278 extern void __key_check(const struct key *);
 279
 280 static inline void key_check(const struct key *key)
 281 {
 282         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 283                 __key_check(key);
 284 }
 285
 286 #else
 287
 288 #define key_check(key) do {} while(0)
 289
 290 #endif
 291
 292 #endif /* _INTERNAL_H */