LXR linux/certs/Makefile

   1# SPDX-License-Identifier: GPL-2.0
   2#
   3# Makefile for the linux kernel signature checking certificates.
   4#
   5
   6obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
   7obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o
   8ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
   9obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
  10else
  11obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
  12endif
  13
  14ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
  15
  16$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
  17
  18# GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
  19$(obj)/system_certificates.o: $(obj)/x509_certificate_list
  20
  21# Cope with signing_key.x509 existing in $(srctree) not $(objtree)
  22AFLAGS_system_certificates.o := -I$(srctree)
  23
  24quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
  25      cmd_extract_certs  = scripts/extract-cert $(2) $@
  26
  27targets += x509_certificate_list
  28$(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
  29        $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
  30endif # CONFIG_SYSTEM_TRUSTED_KEYRING
  31
  32clean-files := x509_certificate_list .x509.list
  33
  34ifeq ($(CONFIG_MODULE_SIG),y)
  35###############################################################################
  36#
  37# If module signing is requested, say by allyesconfig, but a key has not been
  38# supplied, then one will need to be generated to make sure the build does not
  39# fail and that the kernel may be used afterwards.
  40#
  41###############################################################################
  42ifndef CONFIG_MODULE_SIG_HASH
  43$(error Could not determine digest type to use from kernel config)
  44endif
  45
  46redirect_openssl        = 2>&1
  47quiet_redirect_openssl  = 2>&1
  48silent_redirect_openssl = 2>/dev/null
  49
  50# We do it this way rather than having a boolean option for enabling an
  51# external private key, because 'make randconfig' might enable such a
  52# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
  53ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
  54$(obj)/signing_key.pem: $(obj)/x509.genkey
  55        @$(kecho) "###"
  56        @$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
  57        @$(kecho) "###"
  58        @$(kecho) "### If this takes a long time, you might wish to run rngd in the"
  59        @$(kecho) "### background to keep the supply of entropy topped up.  It"
  60        @$(kecho) "### needs to be run as root, and uses a hardware random"
  61        @$(kecho) "### number generator if one is available."
  62        @$(kecho) "###"
  63        $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
  64                -batch -x509 -config $(obj)/x509.genkey \
  65                -outform PEM -out $(obj)/signing_key.pem \
  66                -keyout $(obj)/signing_key.pem \
  67                $($(quiet)redirect_openssl)
  68        @$(kecho) "###"
  69        @$(kecho) "### Key pair generated."
  70        @$(kecho) "###"
  71
  72$(obj)/x509.genkey:
  73        @$(kecho) Generating X.509 key generation config
  74        @echo  >$@ "[ req ]"
  75        @echo >>$@ "default_bits = 4096"
  76        @echo >>$@ "distinguished_name = req_distinguished_name"
  77        @echo >>$@ "prompt = no"
  78        @echo >>$@ "string_mask = utf8only"
  79        @echo >>$@ "x509_extensions = myexts"
  80        @echo >>$@
  81        @echo >>$@ "[ req_distinguished_name ]"
  82        @echo >>$@ "#O = Unspecified company"
  83        @echo >>$@ "CN = Build time autogenerated kernel key"
  84        @echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
  85        @echo >>$@
  86        @echo >>$@ "[ myexts ]"
  87        @echo >>$@ "basicConstraints=critical,CA:FALSE"
  88        @echo >>$@ "keyUsage=digitalSignature"
  89        @echo >>$@ "subjectKeyIdentifier=hash"
  90        @echo >>$@ "authorityKeyIdentifier=keyid"
  91endif # CONFIG_MODULE_SIG_KEY
  92
  93$(eval $(call config_filename,MODULE_SIG_KEY))
  94
  95# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
  96ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
  97X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
  98endif
  99
 100# GCC PR#66871 again.
 101$(obj)/system_certificates.o: $(obj)/signing_key.x509
 102
 103targets += signing_key.x509
 104$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
 105        $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
 106endif # CONFIG_MODULE_SIG
 107