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>
20 struct kernel_pkey_query
;
21 struct kernel_pkey_params
;
24 * key under-construction record
25 * - passed to the request_key actor if supplied
27 struct key_construction
{
28 struct key
*key
; /* key being constructed */
29 struct key
*authkey
;/* authorisation for key being constructed */
33 * Pre-parsed payload, used by key add, update and instantiate.
35 * This struct will be cleared and data and datalen will be set with the data
36 * and length parameters from the caller and quotalen will be set from
37 * def_datalen from the key type. Then if the preparse() op is provided by the
38 * key type, that will be called. Then the struct will be passed to the
39 * instantiate() or the update() op.
41 * If the preparse() op is given, the free_preparse() op will be called to
44 struct key_preparsed_payload
{
45 char *description
; /* Proposed key description (or NULL) */
46 union key_payload payload
; /* Proposed payload */
47 const void *data
; /* Raw data */
48 size_t datalen
; /* Raw datalen */
49 size_t quotalen
; /* Quota length for proposed payload */
50 time64_t expiry
; /* Expiry time of key */
53 typedef int (*request_key_actor_t
)(struct key_construction
*key
,
54 const char *op
, void *aux
);
57 * Preparsed matching criterion.
59 struct key_match_data
{
60 /* Comparison function, defaults to exact description match, but can be
61 * overridden by type->match_preparse(). Should return true if a match
62 * is found and false if not.
64 bool (*cmp
)(const struct key
*key
,
65 const struct key_match_data
*match_data
);
67 const void *raw_data
; /* Raw match data */
68 void *preparsed
; /* For ->match_preparse() to stash stuff */
69 unsigned lookup_type
; /* Type of lookup for this search. */
70 #define KEYRING_SEARCH_LOOKUP_DIRECT 0x0000 /* Direct lookup by description. */
71 #define KEYRING_SEARCH_LOOKUP_ITERATE 0x0001 /* Iterative search. */
75 * kernel managed key type definition
78 /* name of the type */
81 /* default payload length for quota precalculation (optional)
82 * - this can be used instead of calling key_payload_reserve(), that
83 * function only needs to be called if the real datalen is different
87 /* vet a description */
88 int (*vet_description
)(const char *description
);
90 /* Preparse the data blob from userspace that is to be the payload,
91 * generating a proposed description and payload that will be handed to
92 * the instantiate() and update() ops.
94 int (*preparse
)(struct key_preparsed_payload
*prep
);
96 /* Free a preparse data structure.
98 void (*free_preparse
)(struct key_preparsed_payload
*prep
);
100 /* instantiate a key of this type
101 * - this method should call key_payload_reserve() to determine if the
102 * user's quota will hold the payload
104 int (*instantiate
)(struct key
*key
, struct key_preparsed_payload
*prep
);
106 /* update a key of this type (optional)
107 * - this method should call key_payload_reserve() to recalculate the
109 * - the key must be locked against read when modifying
111 int (*update
)(struct key
*key
, struct key_preparsed_payload
*prep
);
113 /* Preparse the data supplied to ->match() (optional). The
114 * data to be preparsed can be found in match_data->raw_data.
115 * The lookup type can also be set by this function.
117 int (*match_preparse
)(struct key_match_data
*match_data
);
119 /* Free preparsed match data (optional). This should be supplied it
120 * ->match_preparse() is supplied. */
121 void (*match_free
)(struct key_match_data
*match_data
);
123 /* clear some of the data from a key on revokation (optional)
124 * - the key's semaphore will be write-locked by the caller
126 void (*revoke
)(struct key
*key
);
128 /* clear the data from a key (optional) */
129 void (*destroy
)(struct key
*key
);
132 void (*describe
)(const struct key
*key
, struct seq_file
*p
);
134 /* read a key's data (optional)
135 * - permission checks will be done by the caller
136 * - the key's semaphore will be readlocked by the caller
137 * - should return the amount of data that could be read, no matter how
138 * much is copied into the buffer
139 * - shouldn't do the copy if the buffer is NULL
141 long (*read
)(const struct key
*key
, char __user
*buffer
, size_t buflen
);
143 /* handle request_key() for this type instead of invoking
144 * /sbin/request-key (optional)
145 * - key is the key to instantiate
146 * - authkey is the authority to assume when instantiating this key
147 * - op is the operation to be done, usually "create"
148 * - the call must not return until the instantiation process has run
151 request_key_actor_t request_key
;
153 /* Look up a keyring access restriction (optional)
155 * - NULL is a valid return value (meaning the requested restriction
156 * is known but will never block addition of a key)
157 * - should return -EINVAL if the restriction is unknown
159 struct key_restriction
*(*lookup_restriction
)(const char *params
);
161 /* Asymmetric key accessor functions. */
162 int (*asym_query
)(const struct kernel_pkey_params
*params
,
163 struct kernel_pkey_query
*info
);
164 int (*asym_eds_op
)(struct kernel_pkey_params
*params
,
165 const void *in
, void *out
);
166 int (*asym_verify_signature
)(struct kernel_pkey_params
*params
,
167 const void *in
, const void *in2
);
169 /* internal fields */
170 struct list_head link
; /* link in types list */
171 struct lock_class_key lock_class
; /* key->sem lock class */
172 } __randomize_layout
;
174 extern struct key_type key_type_keyring
;
176 extern int register_key_type(struct key_type
*ktype
);
177 extern void unregister_key_type(struct key_type
*ktype
);
179 extern int key_payload_reserve(struct key
*key
, size_t datalen
);
180 extern int key_instantiate_and_link(struct key
*key
,
184 struct key
*instkey
);
185 extern int key_reject_and_link(struct key
*key
,
189 struct key
*instkey
);
190 extern void complete_request_key(struct key_construction
*cons
, int error
);
192 static inline int key_negate_and_link(struct key
*key
,
197 return key_reject_and_link(key
, timeout
, ENOKEY
, keyring
, instkey
);
200 extern int generic_key_instantiate(struct key
*key
, struct key_preparsed_payload
*prep
);
202 #endif /* CONFIG_KEYS */
203 #endif /* _LINUX_KEY_TYPE_H */