1 /* Definitions for key type implementations 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells ([email protected]) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public Licence 8 * as published by the Free Software Foundation; either version 9 * 2 of the Licence, or (at your option) any later version. 10 */ 11 12 #ifndef _LINUX_KEY_TYPE_H 13 #define _LINUX_KEY_TYPE_H 14 15 #include <linux/key.h> 16 #include <linux/errno.h> 17 18 #ifdef CONFIG_KEYS 19 20 struct kernel_pkey_query; 21 struct kernel_pkey_params; 22 23 /* 24 * key under-construction record 25 * - passed to the request_key actor if supplied 26 */ 27 struct key_construction { 28 struct key *key; /* key being constructed */ 29 struct key *authkey;/* authorisation for key being constructed */ 30 }; 31 32 /* 33 * Pre-parsed payload, used by key add, update and instantiate. 34 * 35 * This struct will be cleared and data and datalen will be set with the data 36 * and length parameters from the caller and quotalen will be set from 37 * def_datalen from the key type. Then if the preparse() op is provided by the 38 * key type, that will be called. Then the struct will be passed to the 39 * instantiate() or the update() op. 40 * 41 * If the preparse() op is given, the free_preparse() op will be called to 42 * clear the contents. 43 */ 44 struct key_preparsed_payload { 45 char *description; /* Proposed key description (or NULL) */ 46 union key_payload payload; /* Proposed payload */ 47 const void *data; /* Raw data */ 48 size_t datalen; /* Raw datalen */ 49 size_t quotalen; /* Quota length for proposed payload */ 50 time64_t expiry; /* Expiry time of key */ 51 } __randomize_layout; 52 53 typedef int (*request_key_actor_t)(struct key_construction *key, 54 const char *op, void *aux); 55 56 /* 57 * Preparsed matching criterion. 58 */ 59 struct key_match_data { 60 /* Comparison function, defaults to exact description match, but can be 61 * overridden by type->match_preparse(). Should return true if a match 62 * is found and false if not. 63 */ 64 bool (*cmp)(const struct key *key, 65 const struct key_match_data *match_data); 66 67 const void *raw_data; /* Raw match data */ 68 void *preparsed; /* For ->match_preparse() to stash stuff */ 69 unsigned lookup_type; /* Type of lookup for this search. */ 70 #define KEYRING_SEARCH_LOOKUP_DIRECT 0x0000 /* Direct lookup by description. */ 71 #define KEYRING_SEARCH_LOOKUP_ITERATE 0x0001 /* Iterative search. */ 72 }; 73 74 /* 75 * kernel managed key type definition 76 */ 77 struct key_type { 78 /* name of the type */ 79 const char *name; 80 81 /* default payload length for quota precalculation (optional) 82 * - this can be used instead of calling key_payload_reserve(), that 83 * function only needs to be called if the real datalen is different 84 */ 85 size_t def_datalen; 86 87 /* vet a description */ 88 int (*vet_description)(const char *description); 89 90 /* Preparse the data blob from userspace that is to be the payload, 91 * generating a proposed description and payload that will be handed to 92 * the instantiate() and update() ops. 93 */ 94 int (*preparse)(struct key_preparsed_payload *prep); 95 96 /* Free a preparse data structure. 97 */ 98 void (*free_preparse)(struct key_preparsed_payload *prep); 99 100 /* instantiate a key of this type 101 * - this method should call key_payload_reserve() to determine if the 102 * user's quota will hold the payload 103 */ 104 int (*instantiate)(struct key *key, struct key_preparsed_payload *prep); 105 106 /* update a key of this type (optional) 107 * - this method should call key_payload_reserve() to recalculate the 108 * quota consumption 109 * - the key must be locked against read when modifying 110 */ 111 int (*update)(struct key *key, struct key_preparsed_payload *prep); 112 113 /* Preparse the data supplied to ->match() (optional). The 114 * data to be preparsed can be found in match_data->raw_data. 115 * The lookup type can also be set by this function. 116 */ 117 int (*match_preparse)(struct key_match_data *match_data); 118 119 /* Free preparsed match data (optional). This should be supplied it 120 * ->match_preparse() is supplied. */ 121 void (*match_free)(struct key_match_data *match_data); 122 123 /* clear some of the data from a key on revokation (optional) 124 * - the key's semaphore will be write-locked by the caller 125 */ 126 void (*revoke)(struct key *key); 127 128 /* clear the data from a key (optional) */ 129 void (*destroy)(struct key *key); 130 131 /* describe a key */ 132 void (*describe)(const struct key *key, struct seq_file *p); 133 134 /* read a key's data (optional) 135 * - permission checks will be done by the caller 136 * - the key's semaphore will be readlocked by the caller 137 * - should return the amount of data that could be read, no matter how 138 * much is copied into the buffer 139 * - shouldn't do the copy if the buffer is NULL 140 */ 141 long (*read)(const struct key *key, char __user *buffer, size_t buflen); 142 143 /* handle request_key() for this type instead of invoking 144 * /sbin/request-key (optional) 145 * - key is the key to instantiate 146 * - authkey is the authority to assume when instantiating this key 147 * - op is the operation to be done, usually "create" 148 * - the call must not return until the instantiation process has run 149 * its course 150 */ 151 request_key_actor_t request_key; 152 153 /* Look up a keyring access restriction (optional) 154 * 155 * - NULL is a valid return value (meaning the requested restriction 156 * is known but will never block addition of a key) 157 * - should return -EINVAL if the restriction is unknown 158 */ 159 struct key_restriction *(*lookup_restriction)(const char *params); 160 161 /* Asymmetric key accessor functions. */ 162 int (*asym_query)(const struct kernel_pkey_params *params, 163 struct kernel_pkey_query *info); 164 int (*asym_eds_op)(struct kernel_pkey_params *params, 165 const void *in, void *out); 166 int (*asym_verify_signature)(struct kernel_pkey_params *params, 167 const void *in, const void *in2); 168 169 /* internal fields */ 170 struct list_head link; /* link in types list */ 171 struct lock_class_key lock_class; /* key->sem lock class */ 172 } __randomize_layout; 173 174 extern struct key_type key_type_keyring; 175 176 extern int register_key_type(struct key_type *ktype); 177 extern void unregister_key_type(struct key_type *ktype); 178 179 extern int key_payload_reserve(struct key *key, size_t datalen); 180 extern int key_instantiate_and_link(struct key *key, 181 const void *data, 182 size_t datalen, 183 struct key *keyring, 184 struct key *instkey); 185 extern int key_reject_and_link(struct key *key, 186 unsigned timeout, 187 unsigned error, 188 struct key *keyring, 189 struct key *instkey); 190 extern void complete_request_key(struct key_construction *cons, int error); 191 192 static inline int key_negate_and_link(struct key *key, 193 unsigned timeout, 194 struct key *keyring, 195 struct key *instkey) 196 { 197 return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey); 198 } 199 200 extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep); 201 202 #endif /* CONFIG_KEYS */ 203 #endif /* _LINUX_KEY_TYPE_H */ 204