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                             unsigned long *_prealloc);
  94 extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  95 extern void __key_link(struct key *keyring, struct key *key,
  96                        unsigned long *_prealloc);
  97 extern void __key_link_end(struct key *keyring,
  98                            const struct keyring_index_key *index_key,
  99                            unsigned long prealloc);
 100
 101 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 102                                       const struct keyring_index_key *index_key,
 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 struct keyring_search_context {
 111         struct keyring_index_key index_key;
 112         const struct cred       *cred;
 113         key_match_func_t        match;
 114         const void              *match_data;
 115         unsigned                flags;
 116 #define KEYRING_SEARCH_LOOKUP_TYPE      0x0001  /* [as type->def_lookup_type] */
 117 #define KEYRING_SEARCH_NO_STATE_CHECK   0x0002  /* Skip state checks */
 118 #define KEYRING_SEARCH_DO_STATE_CHECK   0x0004  /* Override NO_STATE_CHECK */
 119 #define KEYRING_SEARCH_NO_UPDATE_TIME   0x0008  /* Don't update times */
 120 #define KEYRING_SEARCH_NO_CHECK_PERM    0x0010  /* Don't check permissions */
 121 #define KEYRING_SEARCH_DETECT_TOO_DEEP  0x0020  /* Give an error on excessive depth */
 122
 123         /* Internal stuff */
 124         int                     skipped_ret;
 125         bool                    possessed;
 126         key_ref_t               result;
 127         struct timespec         now;
 128 };
 129
 130 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 131                                     struct keyring_search_context *ctx);
 132
 133 extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
 134 extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
 135
 136 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 137
 138 extern int install_user_keyrings(void);
 139 extern int install_thread_keyring_to_cred(struct cred *);
 140 extern int install_process_keyring_to_cred(struct cred *);
 141 extern int install_session_keyring_to_cred(struct cred *, struct key *);
 142
 143 extern struct key *request_key_and_link(struct key_type *type,
 144                                         const char *description,
 145                                         const void *callout_info,
 146                                         size_t callout_len,
 147                                         void *aux,
 148                                         struct key *dest_keyring,
 149                                         unsigned long flags);
 150
 151 extern int lookup_user_key_possessed(const struct key *key, const void *target);
 152 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 153                                  key_perm_t perm);
 154 #define KEY_LOOKUP_CREATE       0x01
 155 #define KEY_LOOKUP_PARTIAL      0x02
 156 #define KEY_LOOKUP_FOR_UNLINK   0x04
 157
 158 extern long join_session_keyring(const char *name);
 159 extern void key_change_session_keyring(struct callback_head *twork);
 160
 161 extern struct work_struct key_gc_work;
 162 extern unsigned key_gc_delay;
 163 extern void keyring_gc(struct key *keyring, time_t limit);
 164 extern void key_schedule_gc(time_t gc_at);
 165 extern void key_schedule_gc_links(void);
 166 extern void key_gc_keytype(struct key_type *ktype);
 167
 168 extern int key_task_permission(const key_ref_t key_ref,
 169                                const struct cred *cred,
 170                                key_perm_t perm);
 171
 172 /*
 173  * Check to see whether permission is granted to use a key in the desired way.
 174  */
 175 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 176 {
 177         return key_task_permission(key_ref, current_cred(), perm);
 178 }
 179
 180 /* required permissions */
 181 #define KEY_VIEW        0x01    /* require permission to view attributes */
 182 #define KEY_READ        0x02    /* require permission to read content */
 183 #define KEY_WRITE       0x04    /* require permission to update / modify */
 184 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 185 #define KEY_LINK        0x10    /* require permission to link */
 186 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 187 #define KEY_ALL         0x3f    /* all the above permissions */
 188
 189 /*
 190  * Authorisation record for request_key().
 191  */
 192 struct request_key_auth {
 193         struct key              *target_key;
 194         struct key              *dest_keyring;
 195         const struct cred       *cred;
 196         void                    *callout_info;
 197         size_t                  callout_len;
 198         pid_t                   pid;
 199 };
 200
 201 extern struct key_type key_type_request_key_auth;
 202 extern struct key *request_key_auth_new(struct key *target,
 203                                         const void *callout_info,
 204                                         size_t callout_len,
 205                                         struct key *dest_keyring);
 206
 207 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 208
 209 /*
 210  * Determine whether a key is dead.
 211  */
 212 static inline bool key_is_dead(const struct key *key, time_t limit)
 213 {
 214         return
 215                 key->flags & ((1 << KEY_FLAG_DEAD) |
 216                               (1 << KEY_FLAG_INVALIDATED)) ||
 217                 (key->expiry > 0 && key->expiry <= limit);
 218 }
 219
 220 /*
 221  * keyctl() functions
 222  */
 223 extern long keyctl_get_keyring_ID(key_serial_t, int);
 224 extern long keyctl_join_session_keyring(const char __user *);
 225 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 226 extern long keyctl_revoke_key(key_serial_t);
 227 extern long keyctl_keyring_clear(key_serial_t);
 228 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 229 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 230 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 231 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 232                                   const char __user *, key_serial_t);
 233 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 234 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 235 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 236 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 237                                    size_t, key_serial_t);
 238 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 239 extern long keyctl_set_reqkey_keyring(int);
 240 extern long keyctl_set_timeout(key_serial_t, unsigned);
 241 extern long keyctl_assume_authority(key_serial_t);
 242 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 243                                 size_t buflen);
 244 extern long keyctl_session_to_parent(void);
 245 extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 246 extern long keyctl_instantiate_key_iov(key_serial_t,
 247                                        const struct iovec __user *,
 248                                        unsigned, key_serial_t);
 249 extern long keyctl_invalidate_key(key_serial_t);
 250
 251 extern long keyctl_instantiate_key_common(key_serial_t,
 252                                           const struct iovec *,
 253                                           unsigned, size_t, key_serial_t);
 254
 255 /*
 256  * Debugging key validation
 257  */
 258 #ifdef KEY_DEBUGGING
 259 extern void __key_check(const struct key *);
 260
 261 static inline void key_check(const struct key *key)
 262 {
 263         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 264                 __key_check(key);
 265 }
 266
 267 #else
 268
 269 #define key_check(key) do {} while(0)
 270
 271 #endif
 272
 273 #endif /* _INTERNAL_H */