linux/certs/Makefile
Mickaël Salaün addf466389 certs: Check that builtin blacklist hashes are valid
Add and use a check-blacklist-hashes.awk script to make sure that the
builtin blacklist hashes set with CONFIG_SYSTEM_BLACKLIST_HASH_LIST will
effectively be taken into account as blacklisted hashes.  This is useful
to debug invalid hash formats, and it make sure that previous hashes
which could have been loaded in the kernel, but silently ignored, are
now noticed and deal with by the user at kernel build time.

This also prevent stricter blacklist key description checking (provided
by following commits) to failed for builtin hashes.

Update CONFIG_SYSTEM_BLACKLIST_HASH_LIST help to explain the content of
a hash string and how to generate certificate ones.

Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Eric Snowberg <eric.snowberg@oracle.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Link: https://lore.kernel.org/r/20210712170313.884724-3-mic@digikod.net
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2022-05-23 18:47:49 +03:00

91 lines
3.4 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the linux kernel signature checking certificates.
#
obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o common.o
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o common.o
obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o
ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),)
quiet_cmd_check_blacklist_hashes = CHECK $(patsubst "%",%,$(2))
cmd_check_blacklist_hashes = $(AWK) -f $(srctree)/scripts/check-blacklist-hashes.awk $(2); touch $@
$(eval $(call config_filename,SYSTEM_BLACKLIST_HASH_LIST))
$(obj)/blacklist_hashes.o: $(obj)/blacklist_hashes_checked
CFLAGS_blacklist_hashes.o += -I$(srctree)
targets += blacklist_hashes_checked
$(obj)/blacklist_hashes_checked: $(SYSTEM_BLACKLIST_HASH_LIST_SRCPREFIX)$(SYSTEM_BLACKLIST_HASH_LIST_FILENAME) scripts/check-blacklist-hashes.awk FORCE
$(call if_changed,check_blacklist_hashes,$(SYSTEM_BLACKLIST_HASH_LIST_SRCPREFIX)$(CONFIG_SYSTEM_BLACKLIST_HASH_LIST))
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
else
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
endif
quiet_cmd_extract_certs = CERT $@
cmd_extract_certs = $(obj)/extract-cert $(extract-cert-in) $@
extract-cert-in = $(or $(filter-out $(obj)/extract-cert, $(real-prereqs)),"")
$(obj)/system_certificates.o: $(obj)/x509_certificate_list
$(obj)/x509_certificate_list: $(CONFIG_SYSTEM_TRUSTED_KEYS) $(obj)/extract-cert FORCE
$(call if_changed,extract_certs)
targets += x509_certificate_list blacklist_hashes_checked
# If module signing is requested, say by allyesconfig, but a key has not been
# supplied, then one will need to be generated to make sure the build does not
# fail and that the kernel may be used afterwards.
#
# We do it this way rather than having a boolean option for enabling an
# external private key, because 'make randconfig' might enable such a
# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
ifeq ($(CONFIG_MODULE_SIG_KEY),certs/signing_key.pem)
keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_ECDSA) := -newkey ec -pkeyopt ec_paramgen_curve:secp384r1
quiet_cmd_gen_key = GENKEY $@
cmd_gen_key = openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
-batch -x509 -config $< \
-outform PEM -out $@ -keyout $@ $(keytype-y) 2>&1
$(obj)/signing_key.pem: $(obj)/x509.genkey FORCE
$(call if_changed,gen_key)
targets += signing_key.pem
quiet_cmd_copy_x509_config = COPY $@
cmd_copy_x509_config = cat $(srctree)/$(src)/default_x509.genkey > $@
# You can provide your own config file. If not present, copy the default one.
$(obj)/x509.genkey:
$(call cmd,copy_x509_config)
endif # CONFIG_MODULE_SIG_KEY
$(obj)/system_certificates.o: $(obj)/signing_key.x509
PKCS11_URI := $(filter pkcs11:%, $(CONFIG_MODULE_SIG_KEY))
ifdef PKCS11_URI
$(obj)/signing_key.x509: extract-cert-in := $(PKCS11_URI)
endif
$(obj)/signing_key.x509: $(filter-out $(PKCS11_URI),$(CONFIG_MODULE_SIG_KEY)) $(obj)/extract-cert FORCE
$(call if_changed,extract_certs)
targets += signing_key.x509
$(obj)/revocation_certificates.o: $(obj)/x509_revocation_list
$(obj)/x509_revocation_list: $(CONFIG_SYSTEM_REVOCATION_KEYS) $(obj)/extract-cert FORCE
$(call if_changed,extract_certs)
targets += x509_revocation_list
hostprogs := extract-cert
HOSTCFLAGS_extract-cert.o = $(shell pkg-config --cflags libcrypto 2> /dev/null)
HOSTLDLIBS_extract-cert = $(shell pkg-config --libs libcrypto 2> /dev/null || echo -lcrypto)