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
77 /* vet a description */
78 int (*vet_description)(const char *description);
79
80 /* Preparse the data blob from userspace that is to be the payload,
81 * generating a proposed description and payload that will be handed to
82 * the instantiate() and update() ops.
83 */
84 int (*preparse)(struct key_preparsed_payload *prep);
85
86 /* Free a preparse data structure.
87 */
88 void (*free_preparse)(struct key_preparsed_payload *prep);
89
90 /* instantiate a key of this type
91 * - this method should call key_payload_reserve() to determine if the
92 * user's quota will hold the payload
93 */
94 int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
95
96 /* update a key of this type (optional)
97 * - this method should call key_payload_reserve() to recalculate the
98 * quota consumption
99 * - the key must be locked against read when modifying
100 */
101 int (*update)(struct key *key, struct key_preparsed_payload *prep);
102
103 /* Preparse the data supplied to ->match() (optional). The
104 * data to be preparsed can be found in match_data->raw_data.
105 * The lookup type can also be set by this function.
106 */
107 int (*match_preparse)(struct key_match_data *match_data);
108
109 /* Free preparsed match data (optional). This should be supplied it
110 * ->match_preparse() is supplied. */
111 void (*match_free)(struct key_match_data *match_data);
112
113 /* clear some of the data from a key on revokation (optional)
114 * - the key's semaphore will be write-locked by the caller
115 */
116 void (*revoke)(struct key *key);
117
118 /* clear the data from a key (optional) */
119 void (*destroy)(struct key *key);
120
121 /* describe a key */
122 void (*describe)(const struct key *key, struct seq_file *p);
123
124 /* read a key's data (optional)
125 * - permission checks will be done by the caller
126 * - the key's semaphore will be readlocked by the caller
127 * - should return the amount of data that could be read, no matter how
128 * much is copied into the buffer
129 * - shouldn't do the copy if the buffer is NULL
130 */
131 long (*read)(const struct key *key, char *buffer, size_t buflen);
132
133 /* handle request_key() for this type instead of invoking
134 * /sbin/request-key (optional)
135 * - key is the key to instantiate
136 * - authkey is the authority to assume when instantiating this key
137 * - op is the operation to be done, usually "create"
138 * - the call must not return until the instantiation process has run
139 * its course
140 */
141 request_key_actor_t request_key;
142
143 /* Look up a keyring access restriction (optional)
144 *
145 * - NULL is a valid return value (meaning the requested restriction
146 * is known but will never block addition of a key)
147 * - should return -EINVAL if the restriction is unknown
148 */
149 struct key_restriction *(*lookup_restriction)(const char *params);
150
151 /* Asymmetric key accessor functions. */
152 int (*asym_query)(const struct kernel_pkey_params *params,
153 struct kernel_pkey_query *info);
154 int (*asym_eds_op)(struct kernel_pkey_params *params,
155 const void *in, void *out);
156 int (*asym_verify_signature)(struct kernel_pkey_params *params,
157 const void *in, const void *in2);
158
159 /* internal fields */
160 struct list_head link; /* link in types list */
161 struct lock_class_key lock_class; /* key->sem lock class */
162 } __randomize_layout;
163
164 extern struct key_type key_type_keyring;
165
166 extern int register_key_type(struct key_type *ktype);
167 extern void unregister_key_type(struct key_type *ktype);
168
169 extern int key_payload_reserve(struct key *key, size_t datalen);
170 extern int key_instantiate_and_link(struct key *key,
171 const void *data,
172 size_t datalen,
173 struct key *keyring,
174 struct key *authkey);
175 extern int key_reject_and_link(struct key *key,
176 unsigned timeout,
177 unsigned error,
178 struct key *keyring,
179 struct key *authkey);
180 extern void complete_request_key(struct key *authkey, int error);
181
key_negate_and_link(struct key * key,unsigned timeout,struct key * keyring,struct key * authkey)182 static inline int key_negate_and_link(struct key *key,
183 unsigned timeout,
184 struct key *keyring,
185 struct key *authkey)
186 {
187 return key_reject_and_link(key, timeout, ENOKEY, keyring, authkey);
188 }
189
190 extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep);
191
192 #endif /* CONFIG_KEYS */
193 #endif /* _LINUX_KEY_TYPE_H */
194