linux/security/keys/big_key.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* Large capacity key type
 *
 * Copyright (C) 2017-2020 Jason A. Donenfeld <[email protected]>. All Rights Reserved.
 * Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#define pr_fmt(fmt) …
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/file.h>
#include <linux/shmem_fs.h>
#include <linux/err.h>
#include <linux/random.h>
#include <keys/user-type.h>
#include <keys/big_key-type.h>
#include <crypto/chacha20poly1305.h>

/*
 * Layout of key payload words.
 */
struct big_key_payload { … };
#define to_big_key_payload(payload) …

/*
 * If the data is under this limit, there's no point creating a shm file to
 * hold it as the permanently resident metadata for the shmem fs will be at
 * least as large as the data.
 */
#define BIG_KEY_FILE_THRESHOLD …

/*
 * big_key defined keys take an arbitrary string as the description and an
 * arbitrary blob of data as the payload
 */
struct key_type key_type_big_key = …;

/*
 * Preparse a big key
 */
int big_key_preparse(struct key_preparsed_payload *prep)
{ … }

/*
 * Clear preparsement.
 */
void big_key_free_preparse(struct key_preparsed_payload *prep)
{ … }

/*
 * dispose of the links from a revoked keyring
 * - called with the key sem write-locked
 */
void big_key_revoke(struct key *key)
{ … }

/*
 * dispose of the data dangling from the corpse of a big_key key
 */
void big_key_destroy(struct key *key)
{ … }

/*
 * Update a big key
 */
int big_key_update(struct key *key, struct key_preparsed_payload *prep)
{ … }

/*
 * describe the big_key key
 */
void big_key_describe(const struct key *key, struct seq_file *m)
{ … }

/*
 * read the key data
 * - the key's semaphore is read-locked
 */
long big_key_read(const struct key *key, char *buffer, size_t buflen)
{ … }

/*
 * Register key type
 */
static int __init big_key_init(void)
{ … }

late_initcall(big_key_init);