certs/Makefile

   1 #
   2 # Makefile for the linux kernel signature checking certificates.
   3 #
   4
   5 obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
   6 obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o
   7 ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
   8 obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
   9 else
  10 obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
  11 endif
  12 obj-$(CONFIG_EFI_SIGNATURE_LIST_PARSER) += efi_parser.o
  13
  14 obj-$(CONFIG_LOAD_UEFI_KEYS) += load_uefi.o
  15 $(obj)/load_uefi.o: KBUILD_CFLAGS += -fshort-wchar
  16
  17
  18 ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
  19
  20 $(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
  21
  22 # GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
  23 $(obj)/system_certificates.o: $(obj)/x509_certificate_list
  24
  25 # Cope with signing_key.x509 existing in $(srctree) not $(objtree)
  26 AFLAGS_system_certificates.o := -I$(srctree)
  27
  28 quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
  29       cmd_extract_certs  = scripts/extract-cert $(2) $@ || ( rm $@; exit 1)
  30
  31 targets += x509_certificate_list
  32 $(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
  33         $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
  34 endif # CONFIG_SYSTEM_TRUSTED_KEYRING
  35
  36 clean-files := x509_certificate_list .x509.list
  37
  38 ifeq ($(CONFIG_MODULE_SIG),y)
  39 ###############################################################################
  40 #
  41 # If module signing is requested, say by allyesconfig, but a key has not been
  42 # supplied, then one will need to be generated to make sure the build does not
  43 # fail and that the kernel may be used afterwards.
  44 #
  45 ###############################################################################
  46 ifndef CONFIG_MODULE_SIG_HASH
  47 $(error Could not determine digest type to use from kernel config)
  48 endif
  49
  50 redirect_openssl        = 2>&1
  51 quiet_redirect_openssl  = 2>&1
  52 silent_redirect_openssl = 2>/dev/null
  53
  54 # We do it this way rather than having a boolean option for enabling an
  55 # external private key, because 'make randconfig' might enable such a
  56 # boolean option and we unfortunately can't make it depend on !RANDCONFIG.
  57 ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
  58 $(obj)/signing_key.pem: $(obj)/x509.genkey
  59         @$(kecho) "###"
  60         @$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
  61         @$(kecho) "###"
  62         @$(kecho) "### If this takes a long time, you might wish to run rngd in the"
  63         @$(kecho) "### background to keep the supply of entropy topped up.  It"
  64         @$(kecho) "### needs to be run as root, and uses a hardware random"
  65         @$(kecho) "### number generator if one is available."
  66         @$(kecho) "###"
  67         $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
  68                 -batch -x509 -config $(obj)/x509.genkey \
  69                 -outform PEM -out $(obj)/signing_key.pem \
  70                 -keyout $(obj)/signing_key.pem \
  71                 $($(quiet)redirect_openssl)
  72         @$(kecho) "###"
  73         @$(kecho) "### Key pair generated."
  74         @$(kecho) "###"
  75
  76 $(obj)/x509.genkey:
  77         @$(kecho) Generating X.509 key generation config
  78         @echo  >$@ "[ req ]"
  79         @echo >>$@ "default_bits = 4096"
  80         @echo >>$@ "distinguished_name = req_distinguished_name"
  81         @echo >>$@ "prompt = no"
  82         @echo >>$@ "string_mask = utf8only"
  83         @echo >>$@ "x509_extensions = myexts"
  84         @echo >>$@
  85         @echo >>$@ "[ req_distinguished_name ]"
  86         @echo >>$@ "#O = Unspecified company"
  87         @echo >>$@ "CN = Build time autogenerated kernel key"
  88         @echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
  89         @echo >>$@
  90         @echo >>$@ "[ myexts ]"
  91         @echo >>$@ "basicConstraints=critical,CA:FALSE"
  92         @echo >>$@ "keyUsage=digitalSignature"
  93         @echo >>$@ "subjectKeyIdentifier=hash"
  94         @echo >>$@ "authorityKeyIdentifier=keyid"
  95 endif # CONFIG_MODULE_SIG_KEY
  96
  97 $(eval $(call config_filename,MODULE_SIG_KEY))
  98
  99 # If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
 100 ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
 101 X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
 102 endif
 103
 104 # GCC PR#66871 again.
 105 $(obj)/system_certificates.o: $(obj)/signing_key.x509
 106
 107 targets += signing_key.x509
 108 $(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
 109         $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
 110 endif # CONFIG_MODULE_SIG