1 /* Definitions for key type implementations
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #ifndef _LINUX_KEY_TYPE_H
13 #define _LINUX_KEY_TYPE_H
15 #include <linux/key.h>
16 #include <linux/errno.h>
21 * key under-construction record
22 * - passed to the request_key actor if supplied
24 struct key_construction
{
25 struct key
*key
; /* key being constructed */
26 struct key
*authkey
;/* authorisation for key being constructed */
30 * Pre-parsed payload, used by key add, update and instantiate.
32 * This struct will be cleared and data and datalen will be set with the data
33 * and length parameters from the caller and quotalen will be set from
34 * def_datalen from the key type. Then if the preparse() op is provided by the
35 * key type, that will be called. Then the struct will be passed to the
36 * instantiate() or the update() op.
38 * If the preparse() op is given, the free_preparse() op will be called to
41 struct key_preparsed_payload
{
42 char *description
; /* Proposed key description (or NULL) */
43 void *type_data
[2]; /* Private key-type data */
44 void *payload
[2]; /* Proposed payload */
45 const void *data
; /* Raw data */
46 size_t datalen
; /* Raw datalen */
47 size_t quotalen
; /* Quota length for proposed payload */
48 time_t expiry
; /* Expiry time of key */
49 bool trusted
; /* True if key is trusted */
52 typedef int (*request_key_actor_t
)(struct key_construction
*key
,
53 const char *op
, void *aux
);
56 * kernel managed key type definition
59 /* name of the type */
62 /* default payload length for quota precalculation (optional)
63 * - this can be used instead of calling key_payload_reserve(), that
64 * function only needs to be called if the real datalen is different
68 /* Default key search algorithm. */
69 unsigned def_lookup_type
;
70 #define KEYRING_SEARCH_LOOKUP_DIRECT 0x0000 /* Direct lookup by description. */
71 #define KEYRING_SEARCH_LOOKUP_ITERATE 0x0001 /* Iterative search. */
73 /* vet a description */
74 int (*vet_description
)(const char *description
);
76 /* Preparse the data blob from userspace that is to be the payload,
77 * generating a proposed description and payload that will be handed to
78 * the instantiate() and update() ops.
80 int (*preparse
)(struct key_preparsed_payload
*prep
);
82 /* Free a preparse data structure.
84 void (*free_preparse
)(struct key_preparsed_payload
*prep
);
86 /* instantiate a key of this type
87 * - this method should call key_payload_reserve() to determine if the
88 * user's quota will hold the payload
90 int (*instantiate
)(struct key
*key
, struct key_preparsed_payload
*prep
);
92 /* update a key of this type (optional)
93 * - this method should call key_payload_reserve() to recalculate the
95 * - the key must be locked against read when modifying
97 int (*update
)(struct key
*key
, struct key_preparsed_payload
*prep
);
99 /* match a key against a description */
100 int (*match
)(const struct key
*key
, const void *desc
);
102 /* clear some of the data from a key on revokation (optional)
103 * - the key's semaphore will be write-locked by the caller
105 void (*revoke
)(struct key
*key
);
107 /* clear the data from a key (optional) */
108 void (*destroy
)(struct key
*key
);
111 void (*describe
)(const struct key
*key
, struct seq_file
*p
);
113 /* read a key's data (optional)
114 * - permission checks will be done by the caller
115 * - the key's semaphore will be readlocked by the caller
116 * - should return the amount of data that could be read, no matter how
117 * much is copied into the buffer
118 * - shouldn't do the copy if the buffer is NULL
120 long (*read
)(const struct key
*key
, char __user
*buffer
, size_t buflen
);
122 /* handle request_key() for this type instead of invoking
123 * /sbin/request-key (optional)
124 * - key is the key to instantiate
125 * - authkey is the authority to assume when instantiating this key
126 * - op is the operation to be done, usually "create"
127 * - the call must not return until the instantiation process has run
130 request_key_actor_t request_key
;
132 /* internal fields */
133 struct list_head link
; /* link in types list */
134 struct lock_class_key lock_class
; /* key->sem lock class */
137 extern struct key_type key_type_keyring
;
139 extern int register_key_type(struct key_type
*ktype
);
140 extern void unregister_key_type(struct key_type
*ktype
);
142 extern int key_payload_reserve(struct key
*key
, size_t datalen
);
143 extern int key_instantiate_and_link(struct key
*key
,
147 struct key
*instkey
);
148 extern int key_reject_and_link(struct key
*key
,
152 struct key
*instkey
);
153 extern void complete_request_key(struct key_construction
*cons
, int error
);
155 static inline int key_negate_and_link(struct key
*key
,
160 return key_reject_and_link(key
, timeout
, ENOKEY
, keyring
, instkey
);
163 extern int generic_key_instantiate(struct key
*key
, struct key_preparsed_payload
*prep
);
165 #endif /* CONFIG_KEYS */
166 #endif /* _LINUX_KEY_TYPE_H */