certs: use if_changed to re-generate the key when the key type is changed

If the key type of the existing signing key does not match to
CONFIG_MODULE_SIG_KEY_TYPE_*, the Makefile removes it so that it is
re-generated.

Use if_changed so that the key is re-generated when the key type is
changed (that is, the openssl command line is changed).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2021-11-05 12:59:58 +09:00
parent 54c8b517d2
commit e06a61a89c

View File

@ -51,41 +51,23 @@ ifdef SIGN_KEY
#
###############################################################################
openssl_available = $(shell openssl help 2>/dev/null && echo yes)
# We do it this way rather than having a boolean option for enabling an
# external private key, because 'make randconfig' might enable such a
# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
ifeq ($(openssl_available),yes)
X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null)
endif
# Support user changing key type
ifdef CONFIG_MODULE_SIG_KEY_TYPE_ECDSA
keytype_openssl = -newkey ec -pkeyopt ec_paramgen_curve:secp384r1
ifeq ($(openssl_available),yes)
$(if $(findstring id-ecPublicKey,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem"))
endif
endif # CONFIG_MODULE_SIG_KEY_TYPE_ECDSA
ifdef CONFIG_MODULE_SIG_KEY_TYPE_RSA
ifeq ($(openssl_available),yes)
$(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem"))
endif
endif # CONFIG_MODULE_SIG_KEY_TYPE_RSA
keytype-$(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 $(obj)/x509.genkey \
-outform PEM -out $(obj)/signing_key.pem \
-keyout $(obj)/signing_key.pem \
$(keytype_openssl) \
2>&1
-keyout $(obj)/signing_key.pem $(keytype-y) 2>&1
$(obj)/signing_key.pem: $(obj)/x509.genkey
$(call cmd,gen_key)
$(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 > $@