linux-brain/include/keys/system_keyring.h
David Howells 734114f878 KEYS: Add a system blacklist keyring
Add the following:

 (1) A new system keyring that is used to store information about
     blacklisted certificates and signatures.

 (2) A new key type (called 'blacklist') that is used to store a
     blacklisted hash in its description as a hex string.  The key accepts
     no payload.

 (3) The ability to configure a list of blacklisted hashes into the kernel
     at build time.  This is done by setting
     CONFIG_SYSTEM_BLACKLIST_HASH_LIST to the filename of a list of hashes
     that are in the form:

	"<hash>", "<hash>", ..., "<hash>"

     where each <hash> is a hex string representation of the hash and must
     include all necessary leading zeros to pad the hash to the right size.

The above are enabled with CONFIG_SYSTEM_BLACKLIST_KEYRING.

Once the kernel is booted, the blacklist keyring can be listed:

	root@andromeda ~]# keyctl show %:.blacklist
	Keyring
	 723359729 ---lswrv      0     0  keyring: .blacklist
	 676257228 ---lswrv      0     0   \_ blacklist: 123412341234c55c1dcc601ab8e172917706aa32fb5eaf826813547fdf02dd46

The blacklist cannot currently be modified by userspace, but it will be
possible to load it, for example, from the UEFI blacklist database.

A later commit will make it possible to load blacklisted asymmetric keys in
here too.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-03 16:07:24 +01:00

64 lines
1.7 KiB
C

/* System keyring containing trusted public keys.
*
* Copyright (C) 2013 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* 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.
*/
#ifndef _KEYS_SYSTEM_KEYRING_H
#define _KEYS_SYSTEM_KEYRING_H
#include <linux/key.h>
#ifdef CONFIG_SYSTEM_TRUSTED_KEYRING
extern int restrict_link_by_builtin_trusted(struct key *keyring,
const struct key_type *type,
const union key_payload *payload);
#else
#define restrict_link_by_builtin_trusted restrict_link_reject
#endif
#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
extern int restrict_link_by_builtin_and_secondary_trusted(
struct key *keyring,
const struct key_type *type,
const union key_payload *payload);
#else
#define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted
#endif
#ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING
extern int mark_hash_blacklisted(const char *hash);
extern int is_hash_blacklisted(const u8 *hash, size_t hash_len,
const char *type);
#else
static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len,
const char *type)
{
return 0;
}
#endif
#ifdef CONFIG_IMA_BLACKLIST_KEYRING
extern struct key *ima_blacklist_keyring;
static inline struct key *get_ima_blacklist_keyring(void)
{
return ima_blacklist_keyring;
}
#else
static inline struct key *get_ima_blacklist_keyring(void)
{
return NULL;
}
#endif /* CONFIG_IMA_BLACKLIST_KEYRING */
#endif /* _KEYS_SYSTEM_KEYRING_H */