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