#
  # 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