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Release 4.12 include/linux/key-type.h

Directory: include/linux
/* Definitions for key type implementations
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.



#include <linux/key.h>
#include <linux/errno.h>


 * key under-construction record
 * - passed to the request_key actor if supplied

struct key_construction {
struct key	*key;	/* key being constructed */
struct key	*authkey;/* authorisation for key being constructed */

 * Pre-parsed payload, used by key add, update and instantiate.
 * This struct will be cleared and data and datalen will be set with the data
 * and length parameters from the caller and quotalen will be set from
 * def_datalen from the key type.  Then if the preparse() op is provided by the
 * key type, that will be called.  Then the struct will be passed to the
 * instantiate() or the update() op.
 * If the preparse() op is given, the free_preparse() op will be called to
 * clear the contents.

struct key_preparsed_payload {
char		*description;	/* Proposed key description (or NULL) */
union key_payload payload;	/* Proposed payload */
const void	*data;		/* Raw data */
size_t		datalen;	/* Raw datalen */
size_t		quotalen;	/* Quota length for proposed payload */
time_t		expiry;		/* Expiry time of key */

typedef int (*request_key_actor_t)(struct key_construction *key,
				   const char *op, void *aux);

 * Preparsed matching criterion.

struct key_match_data {
	/* Comparison function, defaults to exact description match, but can be
         * overridden by type->match_preparse().  Should return true if a match
         * is found and false if not.
bool (*cmp)(const struct key *key,
		    const struct key_match_data *match_data);

const void	*raw_data;	/* Raw match data */
void		*preparsed;	/* For ->match_preparse() to stash stuff */
unsigned	lookup_type;	/* Type of lookup for this search. */

#define KEYRING_SEARCH_LOOKUP_DIRECT	0x0000	/* Direct lookup by description. */

#define KEYRING_SEARCH_LOOKUP_ITERATE	0x0001	/* Iterative search. */

 * kernel managed key type definition

struct key_type {
	/* name of the type */
const char *name;

	/* default payload length for quota precalculation (optional)
         * - this can be used instead of calling key_payload_reserve(), that
         *   function only needs to be called if the real datalen is different
size_t def_datalen;

	/* vet a description */
int (*vet_description)(const char *description);

	/* Preparse the data blob from userspace that is to be the payload,
         * generating a proposed description and payload that will be handed to
         * the instantiate() and update() ops.
int (*preparse)(struct key_preparsed_payload *prep);

	/* Free a preparse data structure.
void (*free_preparse)(struct key_preparsed_payload *prep);

	/* instantiate a key of this type
         * - this method should call key_payload_reserve() to determine if the
         *   user's quota will hold the payload
int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);

	/* update a key of this type (optional)
         * - this method should call key_payload_reserve() to recalculate the
         *   quota consumption
         * - the key must be locked against read when modifying
int (*update)(struct key *key, struct key_preparsed_payload *prep);

	/* Preparse the data supplied to ->match() (optional).  The
         * data to be preparsed can be found in match_data->raw_data.
         * The lookup type can also be set by this function.
int (*match_preparse)(struct key_match_data *match_data);

	/* Free preparsed match data (optional).  This should be supplied it
         * ->match_preparse() is supplied. */
void (*match_free)(struct key_match_data *match_data);

	/* clear some of the data from a key on revokation (optional)
         * - the key's semaphore will be write-locked by the caller
void (*revoke)(struct key *key);

	/* clear the data from a key (optional) */
void (*destroy)(struct key *key);

	/* describe a key */
void (*describe)(const struct key *key, struct seq_file *p);

	/* read a key's data (optional)
         * - permission checks will be done by the caller
         * - the key's semaphore will be readlocked by the caller
         * - should return the amount of data that could be read, no matter how
         *   much is copied into the buffer
         * - shouldn't do the copy if the buffer is NULL
long (*read)(const struct key *key, char __user *buffer, size_t buflen);

	/* handle request_key() for this type instead of invoking
         * /sbin/request-key (optional)
         * - key is the key to instantiate
         * - authkey is the authority to assume when instantiating this key
         * - op is the operation to be done, usually "create"
         * - the call must not return until the instantiation process has run
         *   its course
request_key_actor_t request_key;

	/* Look up a keyring access restriction (optional)
         * - NULL is a valid return value (meaning the requested restriction
         *   is known but will never block addition of a key)
         * - should return -EINVAL if the restriction is unknown
struct key_restriction *(*lookup_restriction)(const char *params);

	/* internal fields */
struct list_head	link;		/* link in types list */
struct lock_class_key	lock_class;	/* key->sem lock class */

extern struct key_type key_type_keyring;

extern int register_key_type(struct key_type *ktype);
extern void unregister_key_type(struct key_type *ktype);

extern int key_payload_reserve(struct key *key, size_t datalen);
extern int key_instantiate_and_link(struct key *key,
				    const void *data,
				    size_t datalen,
				    struct key *keyring,
				    struct key *instkey);
extern int key_reject_and_link(struct key *key,
			       unsigned timeout,
			       unsigned error,
			       struct key *keyring,
			       struct key *instkey);
extern void complete_request_key(struct key_construction *cons, int error);

static inline int key_negate_and_link(struct key *key, unsigned timeout, struct key *keyring, struct key *instkey) { return key_reject_and_link(key, timeout, ENOKEY, keyring, instkey); }


David Howells39100.00%1100.00%

extern int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep); #endif /* CONFIG_KEYS */ #endif /* _LINUX_KEY_TYPE_H */

Overall Contributors

David Howells50597.12%1191.67%
Mat Martineau152.88%18.33%
Directory: include/linux
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