linux/security/keys/internal.h
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   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#ifdef __KDEBUG
  20#define kenter(FMT, ...) \
  21        printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  22#define kleave(FMT, ...) \
  23        printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  24#define kdebug(FMT, ...) \
  25        printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  26#else
  27#define kenter(FMT, ...) \
  28        no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  29#define kleave(FMT, ...) \
  30        no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  31#define kdebug(FMT, ...) \
  32        no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  33#endif
  34
  35extern struct key_type key_type_dead;
  36extern struct key_type key_type_user;
  37extern struct key_type key_type_logon;
  38
  39/*****************************************************************************/
  40/*
  41 * Keep track of keys for a user.
  42 *
  43 * This needs to be separate to user_struct to avoid a refcount-loop
  44 * (user_struct pins some keyrings which pin this struct).
  45 *
  46 * We also keep track of keys under request from userspace for this UID here.
  47 */
  48struct key_user {
  49        struct rb_node          node;
  50        struct mutex            cons_lock;      /* construction initiation lock */
  51        spinlock_t              lock;
  52        atomic_t                usage;          /* for accessing qnkeys & qnbytes */
  53        atomic_t                nkeys;          /* number of keys */
  54        atomic_t                nikeys;         /* number of instantiated keys */
  55        uid_t                   uid;
  56        struct user_namespace   *user_ns;
  57        int                     qnkeys;         /* number of keys allocated to this user */
  58        int                     qnbytes;        /* number of bytes allocated to this user */
  59};
  60
  61extern struct rb_root   key_user_tree;
  62extern spinlock_t       key_user_lock;
  63extern struct key_user  root_key_user;
  64
  65extern struct key_user *key_user_lookup(uid_t uid,
  66                                        struct user_namespace *user_ns);
  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 key_type *type,
  93                            const char *description,
  94                            unsigned long *_prealloc);
  95extern int __key_link_check_live_key(struct key *keyring, struct key *key);
  96extern void __key_link(struct key *keyring, struct key *key,
  97                       unsigned long *_prealloc);
  98extern void __key_link_end(struct key *keyring,
  99                           struct key_type *type,
 100                           unsigned long prealloc);
 101
 102extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 103                                      const struct key_type *type,
 104                                      const char *description,
 105                                      key_perm_t perm);
 106
 107extern struct key *keyring_search_instkey(struct key *keyring,
 108                                          key_serial_t target_id);
 109
 110typedef int (*key_match_func_t)(const struct key *, const void *);
 111
 112extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 113                                    const struct cred *cred,
 114                                    struct key_type *type,
 115                                    const void *description,
 116                                    key_match_func_t match,
 117                                    bool no_state_check);
 118
 119extern key_ref_t search_my_process_keyrings(struct key_type *type,
 120                                            const void *description,
 121                                            key_match_func_t match,
 122                                            bool no_state_check,
 123                                            const struct cred *cred);
 124extern key_ref_t search_process_keyrings(struct key_type *type,
 125                                         const void *description,
 126                                         key_match_func_t match,
 127                                         const struct cred *cred);
 128
 129extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 130
 131extern int install_user_keyrings(void);
 132extern int install_thread_keyring_to_cred(struct cred *);
 133extern int install_process_keyring_to_cred(struct cred *);
 134extern int install_session_keyring_to_cred(struct cred *, struct key *);
 135
 136extern struct key *request_key_and_link(struct key_type *type,
 137                                        const char *description,
 138                                        const void *callout_info,
 139                                        size_t callout_len,
 140                                        void *aux,
 141                                        struct key *dest_keyring,
 142                                        unsigned long flags);
 143
 144extern int lookup_user_key_possessed(const struct key *key, const void *target);
 145extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 146                                 key_perm_t perm);
 147#define KEY_LOOKUP_CREATE       0x01
 148#define KEY_LOOKUP_PARTIAL      0x02
 149#define KEY_LOOKUP_FOR_UNLINK   0x04
 150
 151extern long join_session_keyring(const char *name);
 152extern void key_change_session_keyring(struct callback_head *twork);
 153
 154extern struct work_struct key_gc_work;
 155extern unsigned key_gc_delay;
 156extern void keyring_gc(struct key *keyring, time_t limit);
 157extern void key_schedule_gc(time_t gc_at);
 158extern void key_schedule_gc_links(void);
 159extern void key_gc_keytype(struct key_type *ktype);
 160
 161extern int key_task_permission(const key_ref_t key_ref,
 162                               const struct cred *cred,
 163                               key_perm_t perm);
 164
 165/*
 166 * Check to see whether permission is granted to use a key in the desired way.
 167 */
 168static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 169{
 170        return key_task_permission(key_ref, current_cred(), perm);
 171}
 172
 173/* required permissions */
 174#define KEY_VIEW        0x01    /* require permission to view attributes */
 175#define KEY_READ        0x02    /* require permission to read content */
 176#define KEY_WRITE       0x04    /* require permission to update / modify */
 177#define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 178#define KEY_LINK        0x10    /* require permission to link */
 179#define KEY_SETATTR     0x20    /* require permission to change attributes */
 180#define KEY_ALL         0x3f    /* all the above permissions */
 181
 182/*
 183 * Authorisation record for request_key().
 184 */
 185struct request_key_auth {
 186        struct key              *target_key;
 187        struct key              *dest_keyring;
 188        const struct cred       *cred;
 189        void                    *callout_info;
 190        size_t                  callout_len;
 191        pid_t                   pid;
 192};
 193
 194extern struct key_type key_type_request_key_auth;
 195extern struct key *request_key_auth_new(struct key *target,
 196                                        const void *callout_info,
 197                                        size_t callout_len,
 198                                        struct key *dest_keyring);
 199
 200extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 201
 202/*
 203 * Determine whether a key is dead.
 204 */
 205static inline bool key_is_dead(struct key *key, time_t limit)
 206{
 207        return
 208                key->flags & ((1 << KEY_FLAG_DEAD) |
 209                              (1 << KEY_FLAG_INVALIDATED)) ||
 210                (key->expiry > 0 && key->expiry <= limit);
 211}
 212
 213/*
 214 * keyctl() functions
 215 */
 216extern long keyctl_get_keyring_ID(key_serial_t, int);
 217extern long keyctl_join_session_keyring(const char __user *);
 218extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 219extern long keyctl_revoke_key(key_serial_t);
 220extern long keyctl_keyring_clear(key_serial_t);
 221extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 222extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 223extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 224extern long keyctl_keyring_search(key_serial_t, const char __user *,
 225                                  const char __user *, key_serial_t);
 226extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 227extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 228extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 229extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 230                                   size_t, key_serial_t);
 231extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 232extern long keyctl_set_reqkey_keyring(int);
 233extern long keyctl_set_timeout(key_serial_t, unsigned);
 234extern long keyctl_assume_authority(key_serial_t);
 235extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 236                                size_t buflen);
 237extern long keyctl_session_to_parent(void);
 238extern long keyctl_reject_key(key_serial_t, unsigned, unsigned, key_serial_t);
 239extern long keyctl_instantiate_key_iov(key_serial_t,
 240                                       const struct iovec __user *,
 241                                       unsigned, key_serial_t);
 242extern long keyctl_invalidate_key(key_serial_t);
 243
 244extern long keyctl_instantiate_key_common(key_serial_t,
 245                                          const struct iovec *,
 246                                          unsigned, size_t, key_serial_t);
 247
 248/*
 249 * Debugging key validation
 250 */
 251#ifdef KEY_DEBUGGING
 252extern void __key_check(const struct key *);
 253
 254static inline void key_check(const struct key *key)
 255{
 256        if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 257                __key_check(key);
 258}
 259
 260#else
 261
 262#define key_check(key) do {} while(0)
 263
 264#endif
 265
 266#endif /* _INTERNAL_H */
 267
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