# # Makefile for the linux kernel signature checking certificates. # obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y) $(eval $(call config_filename,SYSTEM_TRUSTED_KEYS)) # GCC doesn't include .incbin files in -MD generated dependencies (PR#66871) $(obj)/system_certificates.o: $(obj)/x509_certificate_list # Cope with signing_key.x509 existing in $(srctree) not $(objtree) AFLAGS_system_certificates.o := -I$(srctree) quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2)) cmd_extract_certs = scripts/extract-cert $(2) $@ || ( rm $@; exit 1) targets += x509_certificate_list $(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS)) endif clean-files := x509_certificate_list .x509.list ifeq ($(CONFIG_MODULE_SIG),y) ############################################################################### # # 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. # ############################################################################### ifndef CONFIG_MODULE_SIG_HASH $(error Could not determine digest type to use from kernel config) endif redirect_openssl = 2>&1 quiet_redirect_openssl = 2>&1 silent_redirect_openssl = 2>/dev/null # We do it this way rather than having a boolean option for enabling an # external private key, because 'make randconfig' might enable such a # boolean option and we unfortunately can't make it depend on !RANDCONFIG. ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem") $(obj)/signing_key.pem: $(obj)/x509.genkey @$(kecho) "###" @$(kecho) "### Now generating an X.509 key pair to be used for signing modules." @$(kecho) "###" @$(kecho) "### If this takes a long time, you might wish to run rngd in the" @$(kecho) "### background to keep the supply of entropy topped up. It" @$(kecho) "### needs to be run as root, and uses a hardware random" @$(kecho) "### number generator if one is available." @$(kecho) "###" $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \ -batch -x509 -config $(obj)/x509.genkey \ -outform PEM -out $(obj)/signing_key.pem \ -keyout $(obj)/signing_key.pem \ $($(quiet)redirect_openssl) @$(kecho) "###" @$(kecho) "### Key pair generated." @$(kecho) "###" $(obj)/x509.genkey: @$(kecho) Generating X.509 key generation config @echo >$@ "[ req ]" @echo >>$@ "default_bits = 4096" @echo >>$@ "distinguished_name = req_distinguished_name" @echo >>$@ "prompt = no" @echo >>$@ "string_mask = utf8only" @echo >>$@ "x509_extensions = myexts" @echo >>$@ @echo >>$@ "[ req_distinguished_name ]" @echo >>$@ "#O = Unspecified company" @echo >>$@ "CN = Build time autogenerated kernel key" @echo >>$@ "#emailAddress = unspecified.user@unspecified.company" @echo >>$@ @echo >>$@ "[ myexts ]" @echo >>$@ "basicConstraints=critical,CA:FALSE" @echo >>$@ "keyUsage=digitalSignature" @echo >>$@ "subjectKeyIdentifier=hash" @echo >>$@ "authorityKeyIdentifier=keyid" endif $(eval $(call config_filename,MODULE_SIG_KEY)) # If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME))) X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME) endif # GCC PR#66871 again. $(obj)/system_certificates.o: $(obj)/signing_key.x509 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