| 1 | /* Definitions for key type implementations |
| 2 | * |
| 3 | * Copyright (C) 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 Licence |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the Licence, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #ifndef _LINUX_KEY_TYPE_H |
| 13 | #define _LINUX_KEY_TYPE_H |
| 14 | |
| 15 | #include <linux/key.h> |
| 16 | |
| 17 | #ifdef CONFIG_KEYS |
| 18 | |
| 19 | /* |
| 20 | * key under-construction record |
| 21 | * - passed to the request_key actor if supplied |
| 22 | */ |
| 23 | struct key_construction { |
| 24 | struct key *key; /* key being constructed */ |
| 25 | struct key *authkey;/* authorisation for key being constructed */ |
| 26 | }; |
| 27 | |
| 28 | typedef int (*request_key_actor_t)(struct key_construction *key, |
| 29 | const char *op, void *aux); |
| 30 | |
| 31 | /* |
| 32 | * kernel managed key type definition |
| 33 | */ |
| 34 | struct key_type { |
| 35 | /* name of the type */ |
| 36 | const char *name; |
| 37 | |
| 38 | /* default payload length for quota precalculation (optional) |
| 39 | * - this can be used instead of calling key_payload_reserve(), that |
| 40 | * function only needs to be called if the real datalen is different |
| 41 | */ |
| 42 | size_t def_datalen; |
| 43 | |
| 44 | /* vet a description */ |
| 45 | int (*vet_description)(const char *description); |
| 46 | |
| 47 | /* instantiate a key of this type |
| 48 | * - this method should call key_payload_reserve() to determine if the |
| 49 | * user's quota will hold the payload |
| 50 | */ |
| 51 | int (*instantiate)(struct key *key, const void *data, size_t datalen); |
| 52 | |
| 53 | /* update a key of this type (optional) |
| 54 | * - this method should call key_payload_reserve() to recalculate the |
| 55 | * quota consumption |
| 56 | * - the key must be locked against read when modifying |
| 57 | */ |
| 58 | int (*update)(struct key *key, const void *data, size_t datalen); |
| 59 | |
| 60 | /* match a key against a description */ |
| 61 | int (*match)(const struct key *key, const void *desc); |
| 62 | |
| 63 | /* clear some of the data from a key on revokation (optional) |
| 64 | * - the key's semaphore will be write-locked by the caller |
| 65 | */ |
| 66 | void (*revoke)(struct key *key); |
| 67 | |
| 68 | /* clear the data from a key (optional) */ |
| 69 | void (*destroy)(struct key *key); |
| 70 | |
| 71 | /* describe a key */ |
| 72 | void (*describe)(const struct key *key, struct seq_file *p); |
| 73 | |
| 74 | /* read a key's data (optional) |
| 75 | * - permission checks will be done by the caller |
| 76 | * - the key's semaphore will be readlocked by the caller |
| 77 | * - should return the amount of data that could be read, no matter how |
| 78 | * much is copied into the buffer |
| 79 | * - shouldn't do the copy if the buffer is NULL |
| 80 | */ |
| 81 | long (*read)(const struct key *key, char __user *buffer, size_t buflen); |
| 82 | |
| 83 | /* handle request_key() for this type instead of invoking |
| 84 | * /sbin/request-key (optional) |
| 85 | * - key is the key to instantiate |
| 86 | * - authkey is the authority to assume when instantiating this key |
| 87 | * - op is the operation to be done, usually "create" |
| 88 | * - the call must not return until the instantiation process has run |
| 89 | * its course |
| 90 | */ |
| 91 | request_key_actor_t request_key; |
| 92 | |
| 93 | /* internal fields */ |
| 94 | struct list_head link; /* link in types list */ |
| 95 | }; |
| 96 | |
| 97 | extern struct key_type key_type_keyring; |
| 98 | |
| 99 | extern int register_key_type(struct key_type *ktype); |
| 100 | extern void unregister_key_type(struct key_type *ktype); |
| 101 | |
| 102 | extern int key_payload_reserve(struct key *key, size_t datalen); |
| 103 | extern int key_instantiate_and_link(struct key *key, |
| 104 | const void *data, |
| 105 | size_t datalen, |
| 106 | struct key *keyring, |
| 107 | struct key *instkey); |
| 108 | extern int key_reject_and_link(struct key *key, |
| 109 | unsigned timeout, |
| 110 | unsigned error, |
| 111 | struct key *keyring, |
| 112 | struct key *instkey); |
| 113 | extern void complete_request_key(struct key_construction *cons, int error); |
| 114 | |
| 115 | static inline int key_negate_and_link(struct key *key, |
| 116 | unsigned timeout, |
| 117 | struct key *keyring, |
| 118 | struct key *instkey) |
| 119 | { |
| 120 | return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey); |
| 121 | } |
| 122 | |
| 123 | #endif /* CONFIG_KEYS */ |
| 124 | #endif /* _LINUX_KEY_TYPE_H */ |