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
; /* Proposed payload */
45 const void *data
; /* Raw data */
46 size_t datalen
; /* Raw datalen */
47 size_t quotalen
; /* Quota length for proposed payload */
50 typedef int (*request_key_actor_t
)(struct key_construction
*key
,
51 const char *op
, void *aux
);
54 * kernel managed key type definition
57 /* name of the type */
60 /* default payload length for quota precalculation (optional)
61 * - this can be used instead of calling key_payload_reserve(), that
62 * function only needs to be called if the real datalen is different
66 /* vet a description */
67 int (*vet_description
)(const char *description
);
69 /* Preparse the data blob from userspace that is to be the payload,
70 * generating a proposed description and payload that will be handed to
71 * the instantiate() and update() ops.
73 int (*preparse
)(struct key_preparsed_payload
*prep
);
75 /* Free a preparse data structure.
77 void (*free_preparse
)(struct key_preparsed_payload
*prep
);
79 /* instantiate a key of this type
80 * - this method should call key_payload_reserve() to determine if the
81 * user's quota will hold the payload
83 int (*instantiate
)(struct key
*key
, struct key_preparsed_payload
*prep
);
85 /* update a key of this type (optional)
86 * - this method should call key_payload_reserve() to recalculate the
88 * - the key must be locked against read when modifying
90 int (*update
)(struct key
*key
, struct key_preparsed_payload
*prep
);
92 /* match a key against a description */
93 int (*match
)(const struct key
*key
, const void *desc
);
95 /* clear some of the data from a key on revokation (optional)
96 * - the key's semaphore will be write-locked by the caller
98 void (*revoke
)(struct key
*key
);
100 /* clear the data from a key (optional) */
101 void (*destroy
)(struct key
*key
);
104 void (*describe
)(const struct key
*key
, struct seq_file
*p
);
106 /* read a key's data (optional)
107 * - permission checks will be done by the caller
108 * - the key's semaphore will be readlocked by the caller
109 * - should return the amount of data that could be read, no matter how
110 * much is copied into the buffer
111 * - shouldn't do the copy if the buffer is NULL
113 long (*read
)(const struct key
*key
, char __user
*buffer
, size_t buflen
);
115 /* handle request_key() for this type instead of invoking
116 * /sbin/request-key (optional)
117 * - key is the key to instantiate
118 * - authkey is the authority to assume when instantiating this key
119 * - op is the operation to be done, usually "create"
120 * - the call must not return until the instantiation process has run
123 request_key_actor_t request_key
;
125 /* internal fields */
126 struct list_head link
; /* link in types list */
127 struct lock_class_key lock_class
; /* key->sem lock class */
130 extern struct key_type key_type_keyring
;
132 extern int register_key_type(struct key_type
*ktype
);
133 extern void unregister_key_type(struct key_type
*ktype
);
135 extern int key_payload_reserve(struct key
*key
, size_t datalen
);
136 extern int key_instantiate_and_link(struct key
*key
,
140 struct key
*instkey
);
141 extern int key_reject_and_link(struct key
*key
,
145 struct key
*instkey
);
146 extern void complete_request_key(struct key_construction
*cons
, int error
);
148 static inline int key_negate_and_link(struct key
*key
,
153 return key_reject_and_link(key
, timeout
, ENOKEY
, keyring
, instkey
);
156 #endif /* CONFIG_KEYS */
157 #endif /* _LINUX_KEY_TYPE_H */