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