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 #include <linux/android_kabi.h>
14
15 #ifdef CONFIG_KEYS
16
17 struct kernel_pkey_query;
18 struct kernel_pkey_params;
19
20 /*
21 * Pre-parsed payload, used by key add, update and instantiate.
22 *
23 * This struct will be cleared and data and datalen will be set with the data
24 * and length parameters from the caller and quotalen will be set from
25 * def_datalen from the key type. Then if the preparse() op is provided by the
26 * key type, that will be called. Then the struct will be passed to the
27 * instantiate() or the update() op.
28 *
29 * If the preparse() op is given, the free_preparse() op will be called to
30 * clear the contents.
31 */
32 struct key_preparsed_payload {
33 const char *orig_description; /* Actual or proposed description (maybe NULL) */
34 char *description; /* Proposed key description (or NULL) */
35 union key_payload payload; /* Proposed payload */
36 const void *data; /* Raw data */
37 size_t datalen; /* Raw datalen */
38 size_t quotalen; /* Quota length for proposed payload */
39 time64_t expiry; /* Expiry time of key */
40 } __randomize_layout;
41
42 typedef int (*request_key_actor_t)(struct key *auth_key, void *aux);
43
44 /*
45 * Preparsed matching criterion.
46 */
47 struct key_match_data {
48 /* Comparison function, defaults to exact description match, but can be
49 * overridden by type->match_preparse(). Should return true if a match
50 * is found and false if not.
51 */
52 bool (*cmp)(const struct key *key,
53 const struct key_match_data *match_data);
54
55 const void *raw_data; /* Raw match data */
56 void *preparsed; /* For ->match_preparse() to stash stuff */
57 unsigned lookup_type; /* Type of lookup for this search. */
58 #define KEYRING_SEARCH_LOOKUP_DIRECT 0x0000 /* Direct lookup by description. */
59 #define KEYRING_SEARCH_LOOKUP_ITERATE 0x0001 /* Iterative search. */
60 };
61
62 /*
63 * kernel managed key type definition
64 */
65 struct key_type {
66 /* name of the type */
67 const char *name;
68
69 /* default payload length for quota precalculation (optional)
70 * - this can be used instead of calling key_payload_reserve(), that
71 * function only needs to be called if the real datalen is different
72 */
73 size_t def_datalen;
74
75 unsigned int flags;
76 #define KEY_TYPE_NET_DOMAIN 0x00000001 /* Keys of this type have a net namespace domain */
77 #define KEY_TYPE_INSTANT_REAP 0x00000002 /* Keys of this type don't have a delay after expiring */
78
79 /* vet a description */
80 int (*vet_description)(const char *description);
81
82 /* Preparse the data blob from userspace that is to be the payload,
83 * generating a proposed description and payload that will be handed to
84 * the instantiate() and update() ops.
85 */
86 int (*preparse)(struct key_preparsed_payload *prep);
87
88 /* Free a preparse data structure.
89 */
90 void (*free_preparse)(struct key_preparsed_payload *prep);
91
92 /* instantiate a key of this type
93 * - this method should call key_payload_reserve() to determine if the
94 * user's quota will hold the payload
95 */
96 int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
97
98 /* update a key of this type (optional)
99 * - this method should call key_payload_reserve() to recalculate the
100 * quota consumption
101 * - the key must be locked against read when modifying
102 */
103 int (*update)(struct key *key, struct key_preparsed_payload *prep);
104
105 /* Preparse the data supplied to ->match() (optional). The
106 * data to be preparsed can be found in match_data->raw_data.
107 * The lookup type can also be set by this function.
108 */
109 int (*match_preparse)(struct key_match_data *match_data);
110
111 /* Free preparsed match data (optional). This should be supplied it
112 * ->match_preparse() is supplied. */
113 void (*match_free)(struct key_match_data *match_data);
114
115 /* clear some of the data from a key on revokation (optional)
116 * - the key's semaphore will be write-locked by the caller
117 */
118 void (*revoke)(struct key *key);
119
120 /* clear the data from a key (optional) */
121 void (*destroy)(struct key *key);
122
123 /* describe a key */
124 void (*describe)(const struct key *key, struct seq_file *p);
125
126 /* read a key's data (optional)
127 * - permission checks will be done by the caller
128 * - the key's semaphore will be readlocked by the caller
129 * - should return the amount of data that could be read, no matter how
130 * much is copied into the buffer
131 * - shouldn't do the copy if the buffer is NULL
132 */
133 long (*read)(const struct key *key, char *buffer, size_t buflen);
134
135 /* handle request_key() for this type instead of invoking
136 * /sbin/request-key (optional)
137 * - key is the key to instantiate
138 * - authkey is the authority to assume when instantiating this key
139 * - op is the operation to be done, usually "create"
140 * - the call must not return until the instantiation process has run
141 * its course
142 */
143 request_key_actor_t request_key;
144
145 /* Look up a keyring access restriction (optional)
146 *
147 * - NULL is a valid return value (meaning the requested restriction
148 * is known but will never block addition of a key)
149 * - should return -EINVAL if the restriction is unknown
150 */
151 struct key_restriction *(*lookup_restriction)(const char *params);
152
153 /* Asymmetric key accessor functions. */
154 int (*asym_query)(const struct kernel_pkey_params *params,
155 struct kernel_pkey_query *info);
156 int (*asym_eds_op)(struct kernel_pkey_params *params,
157 const void *in, void *out);
158 int (*asym_verify_signature)(struct kernel_pkey_params *params,
159 const void *in, const void *in2);
160
161 ANDROID_KABI_RESERVE(1);
162 ANDROID_KABI_RESERVE(2);
163
164 /* internal fields */
165 struct list_head link; /* link in types list */
166 struct lock_class_key lock_class; /* key->sem lock class */
167 } __randomize_layout;
168
169 extern struct key_type key_type_keyring;
170
171 extern int register_key_type(struct key_type *ktype);
172 extern void unregister_key_type(struct key_type *ktype);
173
174 extern int key_payload_reserve(struct key *key, size_t datalen);
175 extern int key_instantiate_and_link(struct key *key,
176 const void *data,
177 size_t datalen,
178 struct key *keyring,
179 struct key *authkey);
180 extern int key_reject_and_link(struct key *key,
181 unsigned timeout,
182 unsigned error,
183 struct key *keyring,
184 struct key *authkey);
185 extern void complete_request_key(struct key *authkey, int error);
186
key_negate_and_link(struct key * key,unsigned timeout,struct key * keyring,struct key * authkey)187 static inline int key_negate_and_link(struct key *key,
188 unsigned timeout,
189 struct key *keyring,
190 struct key *authkey)
191 {
192 return key_reject_and_link(key, timeout, ENOKEY, keyring, authkey);
193 }
194
195 extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep);
196
197 #endif /* CONFIG_KEYS */
198 #endif /* _LINUX_KEY_TYPE_H */
199