LXR linux/certs/Makefile

   1#
   2# Makefile for the linux kernel signature checking certificates.
   3#
   4
   5obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
   6
   7ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
   8
   9$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
  10
  11# GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
  12$(obj)/system_certificates.o: $(obj)/x509_certificate_list
  13
  14# Cope with signing_key.x509 existing in $(srctree) not $(objtree)
  15AFLAGS_system_certificates.o := -I$(srctree)
  16
  17quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
  18      cmd_extract_certs  = scripts/extract-cert $(2) $@ || ( rm $@; exit 1)
  19
  20targets += x509_certificate_list
  21$(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
  22        $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
  23endif
  24
  25clean-files := x509_certificate_list .x509.list
  26
  27ifeq ($(CONFIG_MODULE_SIG),y)
  28###############################################################################
  29#
  30# If module signing is requested, say by allyesconfig, but a key has not been
  31# supplied, then one will need to be generated to make sure the build does not
  32# fail and that the kernel may be used afterwards.
  33#
  34###############################################################################
  35ifndef CONFIG_MODULE_SIG_HASH
  36$(error Could not determine digest type to use from kernel config)
  37endif
  38
  39redirect_openssl        = 2>&1
  40quiet_redirect_openssl  = 2>&1
  41silent_redirect_openssl = 2>/dev/null
  42
  43# We do it this way rather than having a boolean option for enabling an
  44# external private key, because 'make randconfig' might enable such a
  45# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
  46ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
  47$(obj)/signing_key.pem: $(obj)/x509.genkey
  48        @$(kecho) "###"
  49        @$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
  50        @$(kecho) "###"
  51        @$(kecho) "### If this takes a long time, you might wish to run rngd in the"
  52        @$(kecho) "### background to keep the supply of entropy topped up.  It"
  53        @$(kecho) "### needs to be run as root, and uses a hardware random"
  54        @$(kecho) "### number generator if one is available."
  55        @$(kecho) "###"
  56        $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
  57                -batch -x509 -config $(obj)/x509.genkey \
  58                -outform PEM -out $(obj)/signing_key.pem \
  59                -keyout $(obj)/signing_key.pem \
  60                $($(quiet)redirect_openssl)
  61        @$(kecho) "###"
  62        @$(kecho) "### Key pair generated."
  63        @$(kecho) "###"
  64
  65$(obj)/x509.genkey:
  66        @$(kecho) Generating X.509 key generation config
  67        @echo  >$@ "[ req ]"
  68        @echo >>$@ "default_bits = 4096"
  69        @echo >>$@ "distinguished_name = req_distinguished_name"
  70        @echo >>$@ "prompt = no"
  71        @echo >>$@ "string_mask = utf8only"
  72        @echo >>$@ "x509_extensions = myexts"
  73        @echo >>$@
  74        @echo >>$@ "[ req_distinguished_name ]"
  75        @echo >>$@ "#O = Unspecified company"
  76        @echo >>$@ "CN = Build time autogenerated kernel key"
  77        @echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
  78        @echo >>$@
  79        @echo >>$@ "[ myexts ]"
  80        @echo >>$@ "basicConstraints=critical,CA:FALSE"
  81        @echo >>$@ "keyUsage=digitalSignature"
  82        @echo >>$@ "subjectKeyIdentifier=hash"
  83        @echo >>$@ "authorityKeyIdentifier=keyid"
  84endif
  85
  86$(eval $(call config_filename,MODULE_SIG_KEY))
  87
  88# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
  89ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
  90X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
  91endif
  92
  93# GCC PR#66871 again.
  94$(obj)/system_certificates.o: $(obj)/signing_key.x509
  95
  96targets += signing_key.x509
  97$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
  98        $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
  99endif
 100