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 struct iovec;
  20
  21 #ifdef __KDEBUG
  22 #define kenter(FMT, ...) \
  23         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  24 #define kleave(FMT, ...) \
  25         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  26 #define kdebug(FMT, ...) \
  27         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  28 #else
  29 #define kenter(FMT, ...) \
  30         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  31 #define kleave(FMT, ...) \
  32         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  33 #define kdebug(FMT, ...) \
  34         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  35 #endif
  36
  37 extern struct key_type key_type_dead;
  38 extern struct key_type key_type_user;
  39 extern struct key_type key_type_logon;
  40
  41 /*****************************************************************************/
  42 /*
  43  * Keep track of keys for a user.
  44  *
  45  * This needs to be separate to user_struct to avoid a refcount-loop
  46  * (user_struct pins some keyrings which pin this struct).
  47  *
  48  * We also keep track of keys under request from userspace for this UID here.
  49  */
  50 struct key_user {
  51         struct rb_node          node;
  52         struct mutex            cons_lock;      /* construction initiation lock */
  53         spinlock_t              lock;
  54         atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  55         atomic_t                nkeys;          /* number of keys */
  56         atomic_t                nikeys;         /* number of instantiated keys */
  57         kuid_t                  uid;
  58         int                     qnkeys;         /* number of keys allocated to this user */
  59         int                     qnbytes;        /* number of bytes allocated to this user */
  60 };
  61
  62 extern struct rb_root   key_user_tree;
  63 extern spinlock_t       key_user_lock;
  64 extern struct key_user  root_key_user;
  65
  66 extern struct key_user *key_user_lookup(kuid_t uid);
  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 kmem_cache *key_jar;
  82 extern struct rb_root key_serial_tree;
  83 extern spinlock_t key_serial_lock;
  84 extern struct mutex key_construction_mutex;
  85 extern wait_queue_head_t request_key_conswq;
  86
  87
  88 extern struct key_type *key_type_lookup(const char *type);
  89 extern void key_type_put(struct key_type *ktype);
  90
  91 extern int __key_link_begin(struct key *keyring,
  92                             const struct keyring_index_key *index_key,
  93                             struct assoc_array_edit **_edit);
  94 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  95 extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
  96 extern void __key_link_end(struct key *keyring,
  97                            const struct keyring_index_key *index_key,
  98                            struct assoc_array_edit *edit);
  99
 100 extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 101                                     const struct keyring_index_key *index_key);
 102
 103 extern struct key *keyring_search_instkey(struct key *keyring,
 104                                           key_serial_t target_id);
 105
 106 extern int iterate_over_keyring(const struct key *keyring,
 107                                 int (*func)(const struct key *key, void *data),
 108                                 void *data);
 109
 110 typedef int (*key_match_func_t)(const struct key *, const void *);
 111
 112 struct keyring_search_context {
 113         struct keyring_index_key index_key;
 114         const struct cred       *cred;
 115         key_match_func_t        match;
 116         const void              *match_data;
 117         unsigned                flags;
 118 #define KEYRING_SEARCH_LOOKUP_TYPE      0x0001  /* [as type->def_lookup_type] */
 119 #define KEYRING_SEARCH_NO_STATE_CHECK   0x0002  /* Skip state checks */
 120 #define KEYRING_SEARCH_DO_STATE_CHECK   0x0004  /* Override NO_STATE_CHECK */
 121 #define KEYRING_SEARCH_NO_UPDATE_TIME   0x0008  /* Don't update times */
 122 #define KEYRING_SEARCH_NO_CHECK_PERM    0x0010  /* Don't check permissions */
 123 #define KEYRING_SEARCH_DETECT_TOO_DEEP  0x0020  /* Give an error on excessive depth */
 124
 125         int (*iterator)(const void *object, void *iterator_data);
 126
 127         /* Internal stuff */
 128         int                     skipped_ret;
 129         bool                    possessed;
 130         key_ref_t               result;
 131         struct timespec         now;
 132 };
 133
 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 int lookup_user_key_possessed(const struct key *key, const void *target);
 156 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 157                                  key_perm_t perm);
 158 #define KEY_LOOKUP_CREATE       0x01
 159 #define KEY_LOOKUP_PARTIAL      0x02
 160 #define KEY_LOOKUP_FOR_UNLINK   0x04
 161
 162 extern long join_session_keyring(const char *name);
 163 extern void key_change_session_keyring(struct callback_head *twork);
 164
 165 extern struct work_struct key_gc_work;
 166 extern unsigned key_gc_delay;
 167 extern void keyring_gc(struct key *keyring, time_t limit);
 168 extern void key_schedule_gc(time_t gc_at);
 169 extern void key_schedule_gc_links(void);
 170 extern void key_gc_keytype(struct key_type *ktype);
 171
 172 extern int key_task_permission(const key_ref_t key_ref,
 173                                const struct cred *cred,
 174                                key_perm_t perm);
 175
 176 /*
 177  * Check to see whether permission is granted to use a key in the desired way.
 178  */
 179 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 180 {
 181         return key_task_permission(key_ref, current_cred(), perm);
 182 }
 183
 184 /* required permissions */
 185 #define KEY_VIEW        0x01    /* require permission to view attributes */
 186 #define KEY_READ        0x02    /* require permission to read content */
 187 #define KEY_WRITE       0x04    /* require permission to update / modify */
 188 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 189 #define KEY_LINK        0x10    /* require permission to link */
 190 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 191 #define KEY_ALL         0x3f    /* all the above permissions */
 192
 193 /*
 194  * Authorisation record for request_key().
 195  */
 196 struct request_key_auth {
 197         struct key              *target_key;
 198         struct key              *dest_keyring;
 199         const struct cred       *cred;
 200         void                    *callout_info;
 201         size_t                  callout_len;
 202         pid_t                   pid;
 203 };
 204
 205 extern struct key_type key_type_request_key_auth;
 206 extern struct key *request_key_auth_new(struct key *target,
 207                                         const void *callout_info,
 208                                         size_t callout_len,
 209                                         struct key *dest_keyring);
 210
 211 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 212
 213 /*
 214  * Determine whether a key is dead.
 215  */
 216 static inline bool key_is_dead(const struct key *key, time_t limit)
 217 {
 218         return
 219                 key->flags & ((1 << KEY_FLAG_DEAD) |
 220                               (1 << KEY_FLAG_INVALIDATED)) ||
 221                 (key->expiry > 0 && key->expiry <= limit);
 222 }
 223
 224 /*
 225  * keyctl() functions
 226  */
 227 extern long keyctl_get_keyring_ID(key_serial_t, int);
 228 extern long keyctl_join_session_keyring(const char __user *);
 229 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 230 extern long keyctl_revoke_key(key_serial_t);
 231 extern long keyctl_keyring_clear(key_serial_t);
 232 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 233 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 234 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 235 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 236                                   const char __user *, key_serial_t);
 237 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 238 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 239 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 240 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 241                                    size_t, key_serial_t);
 242 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 243 extern long keyctl_set_reqkey_keyring(int);
 244 extern long keyctl_set_timeout(key_serial_t, unsigned);
 245 extern long keyctl_assume_authority(key_serial_t);
 246 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 247                                 size_t buflen);
 248 extern long keyctl_session_to_parent(void);
 249 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 250 extern long keyctl_instantiate_key_iov(key_serial_t,
 251                                        const struct iovec __user *,
 252                                        unsigned, key_serial_t);
 253 extern long keyctl_invalidate_key(key_serial_t);
 254
 255 extern long keyctl_instantiate_key_common(key_serial_t,
 256                                           const struct iovec *,
 257                                           unsigned, size_t, key_serial_t);
 258 #ifdef CONFIG_PERSISTENT_KEYRINGS
 259 extern long keyctl_get_persistent(uid_t, key_serial_t);
 260 extern unsigned persistent_keyring_expiry;
 261 #else
 262 static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 263 {
 264         return -EOPNOTSUPP;
 265 }
 266 #endif
 267
 268 /*
 269  * Debugging key validation
 270  */
 271 #ifdef KEY_DEBUGGING
 272 extern void __key_check(const struct key *);
 273
 274 static inline void key_check(const struct key *key)
 275 {
 276         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 277                 __key_check(key);
 278 }
 279
 280 #else
 281
 282 #define key_check(key) do {} while(0)
 283
 284 #endif
 285
 286 #endif /* _INTERNAL_H */