1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* Definitions for key type implementations
3 *
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8 #ifndef _LINUX_KEY_TYPE_H
9 #define _LINUX_KEY_TYPE_H
10
11 #include <linux/key.h>
12 #include <linux/errno.h>
13
14 #ifdef CONFIG_KEYS
15
16 struct kernel_pkey_query;
17 struct kernel_pkey_params;
18
19 /*
20 * Pre-parsed payload, used by key add, update and instantiate.
21 *
22 * This struct will be cleared and data and datalen will be set with the data
23 * and length parameters from the caller and quotalen will be set from
24 * def_datalen from the key type. Then if the preparse() op is provided by the
25 * key type, that will be called. Then the struct will be passed to the
26 * instantiate() or the update() op.
27 *
28 * If the preparse() op is given, the free_preparse() op will be called to
29 * clear the contents.
30 */
31 struct key_preparsed_payload {
32 const char *orig_description; /* Actual or proposed description (maybe NULL) */
33 char *description; /* Proposed key description (or NULL) */
34 union key_payload payload; /* Proposed payload */
35 const void *data; /* Raw data */
36 size_t datalen; /* Raw datalen */
37 size_t quotalen; /* Quota length for proposed payload */
38 time64_t expiry; /* Expiry time of key */
39 } __randomize_layout;
40
41 typedef int (*request_key_actor_t)(struct key *auth_key, void *aux);
42
43 /*
44 * Preparsed matching criterion.
45 */
46 struct key_match_data {
47 /* Comparison function, defaults to exact description match, but can be
48 * overridden by type->match_preparse(). Should return true if a match
49 * is found and false if not.
50 */
51 bool (*cmp)(const struct key *key,
52 const struct key_match_data *match_data);
53
54 const void *raw_data; /* Raw match data */
55 void *preparsed; /* For ->match_preparse() to stash stuff */
56 unsigned lookup_type; /* Type of lookup for this search. */
57 #define KEYRING_SEARCH_LOOKUP_DIRECT 0x0000 /* Direct lookup by description. */
58 #define KEYRING_SEARCH_LOOKUP_ITERATE 0x0001 /* Iterative search. */
59 };
60
61 /*
62 * kernel managed key type definition
63 */
64 struct key_type {
65 /* name of the type */
66 const char *name;
67
68 /* default payload length for quota precalculation (optional)
69 * - this can be used instead of calling key_payload_reserve(), that
70 * function only needs to be called if the real datalen is different
71 */
72 size_t def_datalen;
73
74 unsigned int flags;
75 #define KEY_TYPE_NET_DOMAIN 0x00000001 /* Keys of this type have a net namespace domain */
76 #define KEY_TYPE_INSTANT_REAP 0x00000002 /* Keys of this type don't have a delay after expiring */
77
78 /* vet a description */
79 int (*vet_description)(const char *description);
80
81 /* Preparse the data blob from userspace that is to be the payload,
82 * generating a proposed description and payload that will be handed to
83 * the instantiate() and update() ops.
84 */
85 int (*preparse)(struct key_preparsed_payload *prep);
86
87 /* Free a preparse data structure.
88 */
89 void (*free_preparse)(struct key_preparsed_payload *prep);
90
91 /* instantiate a key of this type
92 * - this method should call key_payload_reserve() to determine if the
93 * user's quota will hold the payload
94 */
95 int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
96
97 /* update a key of this type (optional)
98 * - this method should call key_payload_reserve() to recalculate the
99 * quota consumption
100 * - the key must be locked against read when modifying
101 */
102 int (*update)(struct key *key, struct key_preparsed_payload *prep);
103
104 /* Preparse the data supplied to ->match() (optional). The
105 * data to be preparsed can be found in match_data->raw_data.
106 * The lookup type can also be set by this function.
107 */
108 int (*match_preparse)(struct key_match_data *match_data);
109
110 /* Free preparsed match data (optional). This should be supplied it
111 * ->match_preparse() is supplied. */
112 void (*match_free)(struct key_match_data *match_data);
113
114 /* clear some of the data from a key on revokation (optional)
115 * - the key's semaphore will be write-locked by the caller
116 */
117 void (*revoke)(struct key *key);
118
119 /* clear the data from a key (optional) */
120 void (*destroy)(struct key *key);
121
122 /* describe a key */
123 void (*describe)(const struct key *key, struct seq_file *p);
124
125 /* read a key's data (optional)
126 * - permission checks will be done by the caller
127 * - the key's semaphore will be readlocked by the caller
128 * - should return the amount of data that could be read, no matter how
129 * much is copied into the buffer
130 * - shouldn't do the copy if the buffer is NULL
131 */
132 long (*read)(const struct key *key, char *buffer, size_t buflen);
133
134 /* handle request_key() for this type instead of invoking
135 * /sbin/request-key (optional)
136 * - key is the key to instantiate
137 * - authkey is the authority to assume when instantiating this key
138 * - op is the operation to be done, usually "create"
139 * - the call must not return until the instantiation process has run
140 * its course
141 */
142 request_key_actor_t request_key;
143
144 /* Look up a keyring access restriction (optional)
145 *
146 * - NULL is a valid return value (meaning the requested restriction
147 * is known but will never block addition of a key)
148 * - should return -EINVAL if the restriction is unknown
149 */
150 struct key_restriction *(*lookup_restriction)(const char *params);
151
152 /* Asymmetric key accessor functions. */
153 int (*asym_query)(const struct kernel_pkey_params *params,
154 struct kernel_pkey_query *info);
155 int (*asym_eds_op)(struct kernel_pkey_params *params,
156 const void *in, void *out);
157 int (*asym_verify_signature)(struct kernel_pkey_params *params,
158 const void *in, const void *in2);
159
160 /* internal fields */
161 struct list_head link; /* link in types list */
162 struct lock_class_key lock_class; /* key->sem lock class */
163 } __randomize_layout;
164
165 extern struct key_type key_type_keyring;
166
167 extern int register_key_type(struct key_type *ktype);
168 extern void unregister_key_type(struct key_type *ktype);
169
170 extern int key_payload_reserve(struct key *key, size_t datalen);
171 extern int key_instantiate_and_link(struct key *key,
172 const void *data,
173 size_t datalen,
174 struct key *keyring,
175 struct key *authkey);
176 extern int key_reject_and_link(struct key *key,
177 unsigned timeout,
178 unsigned error,
179 struct key *keyring,
180 struct key *authkey);
181 extern void complete_request_key(struct key *authkey, int error);
182
183 static inline int key_negate_and_link(struct key *key,
184 unsigned timeout,
185 struct key *keyring,
186 struct key *authkey)
187 {
188 return key_reject_and_link(key, timeout, ENOKEY, keyring, authkey);
189 }
190
191 extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep);
192
193 #endif /* CONFIG_KEYS */
194 #endif /* _LINUX_KEY_TYPE_H */
195
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