LXR linux/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
  19struct 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
  37extern struct key_type key_type_dead;
  38extern struct key_type key_type_user;
  39extern 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 */
  50struct 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
  62extern struct rb_root   key_user_tree;
  63extern spinlock_t       key_user_lock;
  64extern struct key_user  root_key_user;
  65
  66extern struct key_user *key_user_lookup(kuid_t uid);
  67extern 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 */
  73extern unsigned key_quota_root_maxkeys;
  74extern unsigned key_quota_root_maxbytes;
  75extern unsigned key_quota_maxkeys;
  76extern unsigned key_quota_maxbytes;
  77
  78#define KEYQUOTA_LINK_BYTES     4               /* a link in a keyring is worth 4 bytes */
  79
  80
  81extern struct kmem_cache *key_jar;
  82extern struct rb_root key_serial_tree;
  83extern spinlock_t key_serial_lock;
  84extern struct mutex key_construction_mutex;
  85extern wait_queue_head_t request_key_conswq;
  86
  87
  88extern struct key_type *key_type_lookup(const char *type);
  89extern void key_type_put(struct key_type *ktype);
  90
  91extern int __key_link_begin(struct key *keyring,
  92                            const struct keyring_index_key *index_key,
  93                            struct assoc_array_edit **_edit);
  94extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  95extern void __key_link(struct key *key, struct assoc_array_edit **_edit);
  96extern void __key_link_end(struct key *keyring,
  97                           const struct keyring_index_key *index_key,
  98                           struct assoc_array_edit *edit);
  99
 100extern key_ref_t find_key_to_update(key_ref_t keyring_ref,
 101                                    const struct keyring_index_key *index_key);
 102
 103extern struct key *keyring_search_instkey(struct key *keyring,
 104                                          key_serial_t target_id);
 105
 106extern int iterate_over_keyring(const struct key *keyring,
 107                                int (*func)(const struct key *key, void *data),
 108                                void *data);
 109
 110typedef int (*key_match_func_t)(const struct key *, const void *);
 111
 112struct 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#define KEYRING_SEARCH_SKIP_EXPIRED     0x0040  /* Ignore expired keys (intention to replace) */
 125
 126        int (*iterator)(const void *object, void *iterator_data);
 127
 128        /* Internal stuff */
 129        int                     skipped_ret;
 130        bool                    possessed;
 131        key_ref_t               result;
 132        struct timespec         now;
 133};
 134
 135extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 136                                    struct keyring_search_context *ctx);
 137
 138extern key_ref_t search_my_process_keyrings(struct keyring_search_context *ctx);
 139extern key_ref_t search_process_keyrings(struct keyring_search_context *ctx);
 140
 141extern struct key *find_keyring_by_name(const char *name, bool uid_keyring);
 142
 143extern int install_user_keyrings(void);
 144extern int install_thread_keyring_to_cred(struct cred *);
 145extern int install_process_keyring_to_cred(struct cred *);
 146extern int install_session_keyring_to_cred(struct cred *, struct key *);
 147
 148extern 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
 156extern int lookup_user_key_possessed(const struct key *key, const void *target);
 157extern 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
 163extern long join_session_keyring(const char *name);
 164extern void key_change_session_keyring(struct callback_head *twork);
 165
 166extern struct work_struct key_gc_work;
 167extern unsigned key_gc_delay;
 168extern void keyring_gc(struct key *keyring, time_t limit);
 169extern void key_schedule_gc(time_t gc_at);
 170extern void key_schedule_gc_links(void);
 171extern void key_gc_keytype(struct key_type *ktype);
 172
 173extern 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 */
 180static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 181{
 182        return key_task_permission(key_ref, current_cred(), perm);
 183}
 184
 185/* required permissions */
 186#define KEY_VIEW        0x01    /* require permission to view attributes */
 187#define KEY_READ        0x02    /* require permission to read content */
 188#define KEY_WRITE       0x04    /* require permission to update / modify */
 189#define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 190#define KEY_LINK        0x10    /* require permission to link */
 191#define KEY_SETATTR     0x20    /* require permission to change attributes */
 192#define KEY_ALL         0x3f    /* all the above permissions */
 193
 194/*
 195 * Authorisation record for request_key().
 196 */
 197struct request_key_auth {
 198        struct key              *target_key;
 199        struct key              *dest_keyring;
 200        const struct cred       *cred;
 201        void                    *callout_info;
 202        size_t                  callout_len;
 203        pid_t                   pid;
 204};
 205
 206extern struct key_type key_type_request_key_auth;
 207extern struct key *request_key_auth_new(struct key *target,
 208                                        const void *callout_info,
 209                                        size_t callout_len,
 210                                        struct key *dest_keyring);
 211
 212extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 213
 214/*
 215 * Determine whether a key is dead.
 216 */
 217static inline bool key_is_dead(const struct key *key, time_t limit)
 218{
 219        return
 220                key->flags & ((1 << KEY_FLAG_DEAD) |
 221                              (1 << KEY_FLAG_INVALIDATED)) ||
 222                (key->expiry > 0 && key->expiry <= limit);
 223}
 224
 225/*
 226 * keyctl() functions
 227 */
 228extern long keyctl_get_keyring_ID(key_serial_t, int);
 229extern long keyctl_join_session_keyring(const char __user *);
 230extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 231extern long keyctl_revoke_key(key_serial_t);
 232extern long keyctl_keyring_clear(key_serial_t);
 233extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 234extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 235extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 236extern long keyctl_keyring_search(key_serial_t, const char __user *,
 237                                  const char __user *, key_serial_t);
 238extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 239extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 240extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 241extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 242                                   size_t, key_serial_t);
 243extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 244extern long keyctl_set_reqkey_keyring(int);
 245extern long keyctl_set_timeout(key_serial_t, unsigned);
 246extern long keyctl_assume_authority(key_serial_t);
 247extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 248                                size_t buflen);
 249extern long keyctl_session_to_parent(void);
 250extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 251extern long keyctl_instantiate_key_iov(key_serial_t,
 252                                       const struct iovec __user *,
 253                                       unsigned, key_serial_t);
 254extern long keyctl_invalidate_key(key_serial_t);
 255
 256extern long keyctl_instantiate_key_common(key_serial_t,
 257                                          const struct iovec *,
 258                                          unsigned, size_t, key_serial_t);
 259#ifdef CONFIG_PERSISTENT_KEYRINGS
 260extern long keyctl_get_persistent(uid_t, key_serial_t);
 261extern unsigned persistent_keyring_expiry;
 262#else
 263static inline long keyctl_get_persistent(uid_t uid, key_serial_t destring)
 264{
 265        return -EOPNOTSUPP;
 266}
 267#endif
 268
 269/*
 270 * Debugging key validation
 271 */
 272#ifdef KEY_DEBUGGING
 273extern void __key_check(const struct key *);
 274
 275static inline void key_check(const struct key *key)
 276{
 277        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 278                __key_check(key);
 279}
 280
 281#else
 282
 283#define key_check(key) do {} while(0)
 284
 285#endif
 286
 287#endif /* _INTERNAL_H */
 288