certs: Add ability to preload revocation certs

Add a new Kconfig option called SYSTEM_REVOCATION_KEYS. If set,
this option should be the filename of a PEM-formated file containing
X.509 certificates to be included in the default blacklist keyring.

DH Changes:
 - Make the new Kconfig option depend on SYSTEM_REVOCATION_LIST.
 - Fix SYSTEM_REVOCATION_KEYS=n, but CONFIG_SYSTEM_REVOCATION_LIST=y[1][2].
 - Use CONFIG_SYSTEM_REVOCATION_LIST for extract-cert[3].
 - Use CONFIG_SYSTEM_REVOCATION_LIST for revocation_certificates.o[3].

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Randy Dunlap <rdunlap@infradead.org>
cc: keyrings@vger.kernel.org
Link: https://lore.kernel.org/r/e1c15c74-82ce-3a69-44de-a33af9b320ea@infradead.org/ [1]
Link: https://lore.kernel.org/r/20210303034418.106762-1-eric.snowberg@oracle.com/ [2]
Link: https://lore.kernel.org/r/20210304175030.184131-1-eric.snowberg@oracle.com/ [3]
Link: https://lore.kernel.org/r/20200930201508.35113-3-eric.snowberg@oracle.com/
Link: https://lore.kernel.org/r/20210122181054.32635-4-eric.snowberg@oracle.com/ # v5
Link: https://lore.kernel.org/r/161428673564.677100.4112098280028451629.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/161433312452.902181.4146169951896577982.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161529606657.163428.3340689182456495390.stgit@warthog.procyon.org.uk/ # v3
This commit is contained in:
Eric Snowberg 2021-01-22 13:10:53 -05:00 committed by David Howells
parent 2565ca7f5e
commit d1f044103d
5 changed files with 68 additions and 2 deletions

View File

@ -92,4 +92,12 @@ config SYSTEM_REVOCATION_LIST
blacklist keyring and implements a hook whereby a PKCS#7 message can
be checked to see if it matches such a certificate.
config SYSTEM_REVOCATION_KEYS
string "X.509 certificates to be preloaded into the system blacklist keyring"
depends on SYSTEM_REVOCATION_LIST
help
If set, this option should be the filename of a PEM-formatted file
containing X.509 certificates to be included in the default blacklist
keyring.
endmenu

View File

@ -4,7 +4,8 @@
#
obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o common.o
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o common.o
obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o
ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
else
@ -29,7 +30,7 @@ $(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREF
$(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
endif # CONFIG_SYSTEM_TRUSTED_KEYRING
clean-files := x509_certificate_list .x509.list
clean-files := x509_certificate_list .x509.list x509_revocation_list
ifeq ($(CONFIG_MODULE_SIG),y)
###############################################################################
@ -104,3 +105,17 @@ targets += signing_key.x509
$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
$(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
endif # CONFIG_MODULE_SIG
ifeq ($(CONFIG_SYSTEM_REVOCATION_LIST),y)
$(eval $(call config_filename,SYSTEM_REVOCATION_KEYS))
$(obj)/revocation_certificates.o: $(obj)/x509_revocation_list
quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2))
cmd_extract_certs = scripts/extract-cert $(2) $@
targets += x509_revocation_list
$(obj)/x509_revocation_list: scripts/extract-cert $(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(SYSTEM_REVOCATION_KEYS_FILENAME) FORCE
$(call if_changed,extract_certs,$(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_REVOCATION_KEYS))
endif

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@ -17,9 +17,15 @@
#include <linux/uidgid.h>
#include <keys/system_keyring.h>
#include "blacklist.h"
#include "common.h"
static struct key *blacklist_keyring;
#ifdef CONFIG_SYSTEM_REVOCATION_LIST
extern __initconst const u8 revocation_certificate_list[];
extern __initconst const unsigned long revocation_certificate_list_size;
#endif
/*
* The description must be a type prefix, a colon and then an even number of
* hex digits. The hash is kept in the description.
@ -220,3 +226,18 @@ static int __init blacklist_init(void)
* Must be initialised before we try and load the keys into the keyring.
*/
device_initcall(blacklist_init);
#ifdef CONFIG_SYSTEM_REVOCATION_LIST
/*
* Load the compiled-in list of revocation X.509 certificates.
*/
static __init int load_revocation_certificate_list(void)
{
if (revocation_certificate_list_size)
pr_notice("Loading compiled-in revocation X.509 certificates\n");
return load_certificate_list(revocation_certificate_list, revocation_certificate_list_size,
blacklist_keyring);
}
late_initcall(load_revocation_certificate_list);
#endif

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@ -0,0 +1,21 @@
/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/export.h>
#include <linux/init.h>
__INITRODATA
.align 8
.globl revocation_certificate_list
revocation_certificate_list:
__revocation_list_start:
.incbin "certs/x509_revocation_list"
__revocation_list_end:
.align 8
.globl revocation_certificate_list_size
revocation_certificate_list_size:
#ifdef CONFIG_64BIT
.quad __revocation_list_end - __revocation_list_start
#else
.long __revocation_list_end - __revocation_list_start
#endif

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@ -11,6 +11,7 @@ hostprogs-always-$(CONFIG_ASN1) += asn1_compiler
hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file
hostprogs-always-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += extract-cert
hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert
hostprogs-always-$(CONFIG_SYSTEM_REVOCATION_LIST) += extract-cert
HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include
HOSTCFLAGS_asn1_compiler.o = -I$(srctree)/include