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 ([email protected]) 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 /* vet a description */ 74 int (*vet_description)(const char *description); 75 76 /* Preparse the data blob from userspace that is to be the payload, 77 * generating a proposed description and payload that will be handed to 78 * the instantiate() and update() ops. 79 */ 80 int (*preparse)(struct key_preparsed_payload *prep); 81 82 /* Free a preparse data structure. 83 */ 84 void (*free_preparse)(struct key_preparsed_payload *prep); 85 86 /* instantiate a key of this type 87 * - this method should call key_payload_reserve() to determine if the 88 * user's quota will hold the payload 89 */ 90 int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); 91 92 /* update a key of this type (optional) 93 * - this method should call key_payload_reserve() to recalculate the 94 * quota consumption 95 * - the key must be locked against read when modifying 96 */ 97 int (*update)(struct key *key, struct key_preparsed_payload *prep); 98 99 /* Preparse the data supplied to ->match() (optional). The 100 * data to be preparsed can be found in match_data->raw_data. 101 * The lookup type can also be set by this function. 102 */ 103 int (*match_preparse)(struct key_match_data *match_data); 104 105 /* Free preparsed match data (optional). This should be supplied it 106 * ->match_preparse() is supplied. */ 107 void (*match_free)(struct key_match_data *match_data); 108 109 /* clear some of the data from a key on revokation (optional) 110 * - the key's semaphore will be write-locked by the caller 111 */ 112 void (*revoke)(struct key *key); 113 114 /* clear the data from a key (optional) */ 115 void (*destroy)(struct key *key); 116 117 /* describe a key */ 118 void (*describe)(const struct key *key, struct seq_file *p); 119 120 /* read a key's data (optional) 121 * - permission checks will be done by the caller 122 * - the key's semaphore will be readlocked by the caller 123 * - should return the amount of data that could be read, no matter how 124 * much is copied into the buffer 125 * - shouldn't do the copy if the buffer is NULL 126 */ 127 long (*read)(const struct key *key, char __user *buffer, size_t buflen); 128 129 /* handle request_key() for this type instead of invoking 130 * /sbin/request-key (optional) 131 * - key is the key to instantiate 132 * - authkey is the authority to assume when instantiating this key 133 * - op is the operation to be done, usually "create" 134 * - the call must not return until the instantiation process has run 135 * its course 136 */ 137 request_key_actor_t request_key; 138 139 /* Look up a keyring access restriction (optional) 140 * 141 * - NULL is a valid return value (meaning the requested restriction 142 * is known but will never block addition of a key) 143 * - should return -EINVAL if the restriction is unknown 144 */ 145 struct key_restriction *(*lookup_restriction)(const char *params); 146 147 /* Asymmetric key accessor functions. */ 148 int (*asym_query)(const struct kernel_pkey_params *params, 149 struct kernel_pkey_query *info); 150 int (*asym_eds_op)(struct kernel_pkey_params *params, 151 const void *in, void *out); 152 int (*asym_verify_signature)(struct kernel_pkey_params *params, 153 const void *in, const void *in2); 154 155 /* internal fields */ 156 struct list_head link; /* link in types list */ 157 struct lock_class_key lock_class; /* key->sem lock class */ 158 } __randomize_layout; 159 160 extern struct key_type key_type_keyring; 161 162 extern int register_key_type(struct key_type *ktype); 163 extern void unregister_key_type(struct key_type *ktype); 164 165 extern int key_payload_reserve(struct key *key, size_t datalen); 166 extern int key_instantiate_and_link(struct key *key, 167 const void *data, 168 size_t datalen, 169 struct key *keyring, 170 struct key *authkey); 171 extern int key_reject_and_link(struct key *key, 172 unsigned timeout, 173 unsigned error, 174 struct key *keyring, 175 struct key *authkey); 176 extern void complete_request_key(struct key *authkey, int error); 177 178 static inline int key_negate_and_link(struct key *key, 179 unsigned timeout, 180 struct key *keyring, 181 struct key *authkey) 182 { 183 return key_reject_and_link(key, timeout, ENOKEY, keyring, authkey); 184 } 185 186 extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep); 187 188 #endif /* CONFIG_KEYS */ 189 #endif /* _LINUX_KEY_TYPE_H */ 190