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linux/include/keys/system_keyring.h

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KEYS: Separate the kernel signature checking keyring from module signing Separate the kernel signature checking keyring from module signing so that it can be used by code other than the module-signing code. Signed-off-by: David Howells <dhowells@redhat.com>
2013-08-30 15:07:30 +00:00
/* 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
KEYS: Move the point of trust determination to __key_link() Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 15:14:26 +00:00
#include <linux/key.h>
KEYS: Separate the kernel signature checking keyring from module signing Separate the kernel signature checking keyring from module signing so that it can be used by code other than the module-signing code. Signed-off-by: David Howells <dhowells@redhat.com>
2013-08-30 15:07:30 +00:00
#ifdef CONFIG_SYSTEM_TRUSTED_KEYRING
KEYS: Move the point of trust determination to __key_link() Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 15:14:26 +00:00
extern int restrict_link_by_builtin_trusted(struct key *keyring,
const struct key_type *type,
KEYS: Split role of the keyring pointer for keyring restrict functions The first argument to the restrict_link_func_t functions was a keyring pointer. These functions are called by the key subsystem with this argument set to the destination keyring, but restrict_link_by_signature expects a pointer to the relevant trusted keyring. Restrict functions may need something other than a single struct key pointer to allow or reject key linkage, so the data used to make that decision (such as the trust keyring) is moved to a new, fourth argument. The first argument is now always the destination keyring. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2016-08-30 18:33:13 +00:00
const union key_payload *payload,
struct key *restriction_key);
KEYS: Separate the kernel signature checking keyring from module signing Separate the kernel signature checking keyring from module signing so that it can be used by code other than the module-signing code. Signed-off-by: David Howells <dhowells@redhat.com>
2013-08-30 15:07:30 +00:00
KEYS: verify a certificate is signed by a 'trusted' key Only public keys, with certificates signed by an existing 'trusted' key on the system trusted keyring, should be added to a trusted keyring. This patch adds support for verifying a certificate's signature. This is derived from David Howells pkcs7_request_asymmetric_key() patch. Changelog v6: - on error free key - Dmitry - validate trust only for not already trusted keys - Dmitry - formatting cleanup Changelog: - define get_system_trusted_keyring() to fix kbuild issues Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
2013-08-20 18:36:27 +00:00
#else
KEYS: Move the point of trust determination to __key_link() Move the point at which a key is determined to be trustworthy to __key_link() so that we use the contents of the keyring being linked in to to determine whether the key being linked in is trusted or not. What is 'trusted' then becomes a matter of what's in the keyring. Currently, the test is done when the key is parsed, but given that at that point we can only sensibly refer to the contents of the system trusted keyring, we can only use that as the basis for working out the trustworthiness of a new key. With this change, a trusted keyring is a set of keys that once the trusted-only flag is set cannot be added to except by verification through one of the contained keys. Further, adding a key into a trusted keyring, whilst it might grant trustworthiness in the context of that keyring, does not automatically grant trustworthiness in the context of a second keyring to which it could be secondarily linked. To accomplish this, the authentication data associated with the key source must now be retained. For an X.509 cert, this means the contents of the AuthorityKeyIdentifier and the signature data. If system keyrings are disabled then restrict_link_by_builtin_trusted() resolves to restrict_link_reject(). The integrity digital signature code still works correctly with this as it was previously using KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there is no system keyring against which trust can be determined. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 15:14:26 +00:00
#define restrict_link_by_builtin_trusted restrict_link_reject
KEYS: Separate the kernel signature checking keyring from module signing Separate the kernel signature checking keyring from module signing so that it can be used by code other than the module-signing code. Signed-off-by: David Howells <dhowells@redhat.com>
2013-08-30 15:07:30 +00:00
#endif
certs: Add a secondary system keyring that can be added to dynamically Add a secondary system keyring that can be added to by root whilst the system is running - provided the key being added is vouched for by a key built into the kernel or already added to the secondary keyring. Rename .system_keyring to .builtin_trusted_keys to distinguish it more obviously from the new keyring (called .secondary_trusted_keys). The new keyring needs to be enabled with CONFIG_SECONDARY_TRUSTED_KEYRING. If the secondary keyring is enabled, a link is created from that to .builtin_trusted_keys so that the the latter will automatically be searched too if the secondary keyring is searched. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 15:14:27 +00:00
#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
extern int restrict_link_by_builtin_and_secondary_trusted(
struct key *keyring,
const struct key_type *type,
KEYS: Split role of the keyring pointer for keyring restrict functions The first argument to the restrict_link_func_t functions was a keyring pointer. These functions are called by the key subsystem with this argument set to the destination keyring, but restrict_link_by_signature expects a pointer to the relevant trusted keyring. Restrict functions may need something other than a single struct key pointer to allow or reject key linkage, so the data used to make that decision (such as the trust keyring) is moved to a new, fourth argument. The first argument is now always the destination keyring. Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2016-08-30 18:33:13 +00:00
const union key_payload *payload,
struct key *restriction_key);
certs: Add a secondary system keyring that can be added to dynamically Add a secondary system keyring that can be added to by root whilst the system is running - provided the key being added is vouched for by a key built into the kernel or already added to the secondary keyring. Rename .system_keyring to .builtin_trusted_keys to distinguish it more obviously from the new keyring (called .secondary_trusted_keys). The new keyring needs to be enabled with CONFIG_SECONDARY_TRUSTED_KEYRING. If the secondary keyring is enabled, a link is created from that to .builtin_trusted_keys so that the the latter will automatically be searched too if the secondary keyring is searched. Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 15:14:27 +00:00
#else
#define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted
#endif
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 15:07:24 +00:00
#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
IMA: Use the the system trusted keyrings instead of .ima_mok Add a config option (IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY) that, when enabled, allows keys to be added to the IMA keyrings by userspace - with the restriction that each must be signed by a key in the system trusted keyrings. EPERM will be returned if this option is disabled, ENOKEY will be returned if no authoritative key can be found and EKEYREJECTED will be returned if the signature doesn't match. Other errors such as ENOPKG may also be returned. If this new option is enabled, the builtin system keyring is searched, as is the secondary system keyring if that is also enabled. Intermediate keys between the builtin system keyring and the key being added can be added to the secondary keyring (which replaces .ima_mok) to form a trust chain - provided they are also validly signed by a key in one of the trusted keyrings. The .ima_mok keyring is then removed and the IMA blacklist keyring gets its own config option (IMA_BLACKLIST_KEYRING). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-04-07 08:45:23 +00:00
#ifdef CONFIG_IMA_BLACKLIST_KEYRING
IMA: create machine owner and blacklist keyrings This option creates IMA MOK and blacklist keyrings. IMA MOK is an intermediate keyring that sits between .system and .ima keyrings, effectively forming a simple CA hierarchy. To successfully import a key into .ima_mok it must be signed by a key which CA is in .system keyring. On turn any key that needs to go in .ima keyring must be signed by CA in either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot. IMA blacklist keyring contains all revoked IMA keys. It is consulted before any other keyring. If the search is successful the requested operation is rejected and error is returned to the caller. Signed-off-by: Petko Manolov <petkan@mip-labs.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-02 15:47:55 +00:00
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;
}
IMA: Use the the system trusted keyrings instead of .ima_mok Add a config option (IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY) that, when enabled, allows keys to be added to the IMA keyrings by userspace - with the restriction that each must be signed by a key in the system trusted keyrings. EPERM will be returned if this option is disabled, ENOKEY will be returned if no authoritative key can be found and EKEYREJECTED will be returned if the signature doesn't match. Other errors such as ENOPKG may also be returned. If this new option is enabled, the builtin system keyring is searched, as is the secondary system keyring if that is also enabled. Intermediate keys between the builtin system keyring and the key being added can be added to the secondary keyring (which replaces .ima_mok) to form a trust chain - provided they are also validly signed by a key in one of the trusted keyrings. The .ima_mok keyring is then removed and the IMA blacklist keyring gets its own config option (IMA_BLACKLIST_KEYRING). Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-04-07 08:45:23 +00:00
#endif /* CONFIG_IMA_BLACKLIST_KEYRING */
IMA: create machine owner and blacklist keyrings This option creates IMA MOK and blacklist keyrings. IMA MOK is an intermediate keyring that sits between .system and .ima keyrings, effectively forming a simple CA hierarchy. To successfully import a key into .ima_mok it must be signed by a key which CA is in .system keyring. On turn any key that needs to go in .ima keyring must be signed by CA in either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot. IMA blacklist keyring contains all revoked IMA keys. It is consulted before any other keyring. If the search is successful the requested operation is rejected and error is returned to the caller. Signed-off-by: Petko Manolov <petkan@mip-labs.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-02 15:47:55 +00:00
integrity, KEYS: add a reference to platform keyring commit 9dc92c45177a ("integrity: Define a trusted platform keyring") introduced a .platform keyring for storing preboot keys, used for verifying kernel image signatures. Currently only IMA-appraisal is able to use the keyring to verify kernel images that have their signature stored in xattr. This patch exposes the .platform keyring, making it accessible for verifying PE signed kernel images as well. Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Kairui Song <kasong@redhat.com> Cc: David Howells <dhowells@redhat.com> [zohar@linux.ibm.com: fixed checkpatch errors, squashed with patch fix] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-01-21 09:59:28 +00:00
#if defined(CONFIG_INTEGRITY_PLATFORM_KEYRING) && \
defined(CONFIG_SYSTEM_TRUSTED_KEYRING)
extern void __init set_platform_trusted_keys(struct key *keyring);
#else
static inline void set_platform_trusted_keys(struct key *keyring)
{
}
#endif
IMA: create machine owner and blacklist keyrings This option creates IMA MOK and blacklist keyrings. IMA MOK is an intermediate keyring that sits between .system and .ima keyrings, effectively forming a simple CA hierarchy. To successfully import a key into .ima_mok it must be signed by a key which CA is in .system keyring. On turn any key that needs to go in .ima keyring must be signed by CA in either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot. IMA blacklist keyring contains all revoked IMA keys. It is consulted before any other keyring. If the search is successful the requested operation is rejected and error is returned to the caller. Signed-off-by: Petko Manolov <petkan@mip-labs.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-12-02 15:47:55 +00:00
KEYS: Separate the kernel signature checking keyring from module signing Separate the kernel signature checking keyring from module signing so that it can be used by code other than the module-signing code. Signed-off-by: David Howells <dhowells@redhat.com>
2013-08-30 15:07:30 +00:00
#endif /* _KEYS_SYSTEM_KEYRING_H */
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