1 /* Definitions for key type implementations 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells ([email protected]) 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 /* instantiate a key of this type 45 * - this method should call key_payload_reserve() to determine if the 46 * user's quota will hold the payload 47 */ 48 int (*instantiate)(struct key *key, const void *data, size_t datalen); 49 50 /* update a key of this type (optional) 51 * - this method should call key_payload_reserve() to recalculate the 52 * quota consumption 53 * - the key must be locked against read when modifying 54 */ 55 int (*update)(struct key *key, const void *data, size_t datalen); 56 57 /* match a key against a description */ 58 int (*match)(const struct key *key, const void *desc); 59 60 /* clear some of the data from a key on revokation (optional) 61 * - the key's semaphore will be write-locked by the caller 62 */ 63 void (*revoke)(struct key *key); 64 65 /* clear the data from a key (optional) */ 66 void (*destroy)(struct key *key); 67 68 /* describe a key */ 69 void (*describe)(const struct key *key, struct seq_file *p); 70 71 /* read a key's data (optional) 72 * - permission checks will be done by the caller 73 * - the key's semaphore will be readlocked by the caller 74 * - should return the amount of data that could be read, no matter how 75 * much is copied into the buffer 76 * - shouldn't do the copy if the buffer is NULL 77 */ 78 long (*read)(const struct key *key, char __user *buffer, size_t buflen); 79 80 /* handle request_key() for this type instead of invoking 81 * /sbin/request-key (optional) 82 * - key is the key to instantiate 83 * - authkey is the authority to assume when instantiating this key 84 * - op is the operation to be done, usually "create" 85 * - the call must not return until the instantiation process has run 86 * its course 87 */ 88 request_key_actor_t request_key; 89 90 /* internal fields */ 91 struct list_head link; /* link in types list */ 92 }; 93 94 extern struct key_type key_type_keyring; 95 96 extern int register_key_type(struct key_type *ktype); 97 extern void unregister_key_type(struct key_type *ktype); 98 99 extern int key_payload_reserve(struct key *key, size_t datalen); 100 extern int key_instantiate_and_link(struct key *key, 101 const void *data, 102 size_t datalen, 103 struct key *keyring, 104 struct key *instkey); 105 extern int key_negate_and_link(struct key *key, 106 unsigned timeout, 107 struct key *keyring, 108 struct key *instkey); 109 extern void complete_request_key(struct key_construction *cons, int error); 110 111 #endif /* CONFIG_KEYS */ 112 #endif /* _LINUX_KEY_TYPE_H */ 113