security/keys/internal.h

   1 /* internal.h: 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
  18 static inline __attribute__((format(printf, 1, 2)))
  19 void no_printk(const char *fmt, ...)
  20 {
  21 }
  22
  23 #ifdef __KDEBUG
  24 #define kenter(FMT, ...) \
  25         printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  26 #define kleave(FMT, ...) \
  27         printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  28 #define kdebug(FMT, ...) \
  29         printk(KERN_DEBUG "   "FMT"\n", ##__VA_ARGS__)
  30 #else
  31 #define kenter(FMT, ...) \
  32         no_printk(KERN_DEBUG "==> %s("FMT")\n", __func__, ##__VA_ARGS__)
  33 #define kleave(FMT, ...) \
  34         no_printk(KERN_DEBUG "<== %s()"FMT"\n", __func__, ##__VA_ARGS__)
  35 #define kdebug(FMT, ...) \
  36         no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
  37 #endif
  38
  39 extern struct key_type key_type_user;
  40
  41 /*****************************************************************************/
  42 /*
  43  * keep track of keys for a user
  44  * - this needs to be separate to user_struct to avoid a refcount-loop
  45  *   (user_struct pins some keyrings which pin this struct)
  46  * - this also keeps track of keys under request from userspace for this UID
  47  */
  48 struct 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
  61 extern struct rb_root   key_user_tree;
  62 extern spinlock_t       key_user_lock;
  63 extern struct key_user  root_key_user;
  64
  65 extern struct key_user *key_user_lookup(uid_t uid,
  66                                         struct user_namespace *user_ns);
  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 rb_root key_serial_tree;
  82 extern spinlock_t key_serial_lock;
  83 extern struct mutex key_construction_mutex;
  84 extern wait_queue_head_t request_key_conswq;
  85
  86
  87 extern struct key_type *key_type_lookup(const char *type);
  88 extern void key_type_put(struct key_type *ktype);
  89
  90 extern int __key_link_begin(struct key *keyring,
  91                             const struct key_type *type,
  92                             const char *description,
  93                             struct keyring_list **_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                        struct keyring_list **_prealloc);
  97 extern void __key_link_end(struct key *keyring,
  98                            struct key_type *type,
  99                            struct keyring_list *prealloc);
 100
 101 extern key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 102                                       const struct key_type *type,
 103                                       const char *description,
 104                                       key_perm_t perm);
 105
 106 extern struct key *keyring_search_instkey(struct key *keyring,
 107                                           key_serial_t target_id);
 108
 109 typedef int (*key_match_func_t)(const struct key *, const void *);
 110
 111 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 112                                     const struct cred *cred,
 113                                     struct key_type *type,
 114                                     const void *description,
 115                                     key_match_func_t match);
 116
 117 extern key_ref_t search_process_keyrings(struct key_type *type,
 118                                          const void *description,
 119                                          key_match_func_t match,
 120                                          const struct cred *cred);
 121
 122 extern struct key *find_keyring_by_name(const char *name, bool skip_perm_check);
 123
 124 extern int install_user_keyrings(void);
 125 extern int install_thread_keyring_to_cred(struct cred *);
 126 extern int install_process_keyring_to_cred(struct cred *);
 127
 128 extern struct key *request_key_and_link(struct key_type *type,
 129                                         const char *description,
 130                                         const void *callout_info,
 131                                         size_t callout_len,
 132                                         void *aux,
 133                                         struct key *dest_keyring,
 134                                         unsigned long flags);
 135
 136 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 137                                  key_perm_t perm);
 138 #define KEY_LOOKUP_CREATE       0x01
 139 #define KEY_LOOKUP_PARTIAL      0x02
 140 #define KEY_LOOKUP_FOR_UNLINK   0x04
 141
 142 extern long join_session_keyring(const char *name);
 143
 144 extern unsigned key_gc_delay;
 145 extern void keyring_gc(struct key *keyring, time_t limit);
 146 extern void key_schedule_gc(time_t expiry_at);
 147
 148 /*
 149  * check to see whether permission is granted to use a key in the desired way
 150  */
 151 extern int key_task_permission(const key_ref_t key_ref,
 152                                const struct cred *cred,
 153                                key_perm_t perm);
 154
 155 static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
 156 {
 157         return key_task_permission(key_ref, current_cred(), perm);
 158 }
 159
 160 /* required permissions */
 161 #define KEY_VIEW        0x01    /* require permission to view attributes */
 162 #define KEY_READ        0x02    /* require permission to read content */
 163 #define KEY_WRITE       0x04    /* require permission to update / modify */
 164 #define KEY_SEARCH      0x08    /* require permission to search (keyring) or find (key) */
 165 #define KEY_LINK        0x10    /* require permission to link */
 166 #define KEY_SETATTR     0x20    /* require permission to change attributes */
 167 #define KEY_ALL         0x3f    /* all the above permissions */
 168
 169 /*
 170  * request_key authorisation
 171  */
 172 struct request_key_auth {
 173         struct key              *target_key;
 174         struct key              *dest_keyring;
 175         const struct cred       *cred;
 176         void                    *callout_info;
 177         size_t                  callout_len;
 178         pid_t                   pid;
 179 };
 180
 181 extern struct key_type key_type_request_key_auth;
 182 extern struct key *request_key_auth_new(struct key *target,
 183                                         const void *callout_info,
 184                                         size_t callout_len,
 185                                         struct key *dest_keyring);
 186
 187 extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 188
 189 /*
 190  * keyctl functions
 191  */
 192 extern long keyctl_get_keyring_ID(key_serial_t, int);
 193 extern long keyctl_join_session_keyring(const char __user *);
 194 extern long keyctl_update_key(key_serial_t, const void __user *, size_t);
 195 extern long keyctl_revoke_key(key_serial_t);
 196 extern long keyctl_keyring_clear(key_serial_t);
 197 extern long keyctl_keyring_link(key_serial_t, key_serial_t);
 198 extern long keyctl_keyring_unlink(key_serial_t, key_serial_t);
 199 extern long keyctl_describe_key(key_serial_t, char __user *, size_t);
 200 extern long keyctl_keyring_search(key_serial_t, const char __user *,
 201                                   const char __user *, key_serial_t);
 202 extern long keyctl_read_key(key_serial_t, char __user *, size_t);
 203 extern long keyctl_chown_key(key_serial_t, uid_t, gid_t);
 204 extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 205 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 206                                    size_t, key_serial_t);
 207 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
 208 extern long keyctl_set_reqkey_keyring(int);
 209 extern long keyctl_set_timeout(key_serial_t, unsigned);
 210 extern long keyctl_assume_authority(key_serial_t);
 211 extern long keyctl_get_security(key_serial_t keyid, char __user *buffer,
 212                                 size_t buflen);
 213 extern long keyctl_session_to_parent(void);
 214
 215 /*
 216  * debugging key validation
 217  */
 218 #ifdef KEY_DEBUGGING
 219 extern void __key_check(const struct key *);
 220
 221 static inline void key_check(const struct key *key)
 222 {
 223         if (key && (IS_ERR(key) || key->magic != KEY_DEBUG_MAGIC))
 224                 __key_check(key);
 225 }
 226
 227 #else
 228
 229 #define key_check(key) do {} while(0)
 230
 231 #endif
 232
 233 #endif /* _INTERNAL_H */