LXR linux/certs/Makefile

   1# SPDX-License-Identifier: GPL-2.0
   2#
   3# Makefile for the linux kernel signature checking certificates.
   4#
   5
   6obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o common.o
   7obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o common.o
   8obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o
   9ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
  10obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
  11else
  12obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
  13endif
  14
  15ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
  16
  17$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
  18
  19# GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
  20$(obj)/system_certificates.o: $(obj)/x509_certificate_list
  21
  22# Cope with signing_key.x509 existing in $(srctree) not $(objtree)
  23AFLAGS_system_certificates.o := -I$(srctree)
  24
  25quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
  26      cmd_extract_certs  = scripts/extract-cert $(2) $@
  27
  28targets += x509_certificate_list
  29$(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
  30        $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
  31endif # CONFIG_SYSTEM_TRUSTED_KEYRING
  32
  33clean-files := x509_certificate_list .x509.list x509_revocation_list
  34
  35ifeq ($(CONFIG_MODULE_SIG),y)
  36        SIGN_KEY = y
  37endif
  38
  39ifeq ($(CONFIG_IMA_APPRAISE_MODSIG),y)
  40ifeq ($(CONFIG_MODULES),y)
  41        SIGN_KEY = y
  42endif
  43endif
  44
  45ifdef SIGN_KEY
  46###############################################################################
  47#
  48# If module signing is requested, say by allyesconfig, but a key has not been
  49# supplied, then one will need to be generated to make sure the build does not
  50# fail and that the kernel may be used afterwards.
  51#
  52###############################################################################
  53ifndef CONFIG_MODULE_SIG_HASH
  54$(error Could not determine digest type to use from kernel config)
  55endif
  56
  57redirect_openssl        = 2>&1
  58quiet_redirect_openssl  = 2>&1
  59silent_redirect_openssl = 2>/dev/null
  60openssl_available       = $(shell openssl help 2>/dev/null && echo yes)
  61
  62# We do it this way rather than having a boolean option for enabling an
  63# external private key, because 'make randconfig' might enable such a
  64# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
  65ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
  66
  67ifeq ($(openssl_available),yes)
  68X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null)
  69endif
  70
  71# Support user changing key type
  72ifdef CONFIG_MODULE_SIG_KEY_TYPE_ECDSA
  73keytype_openssl = -newkey ec -pkeyopt ec_paramgen_curve:secp384r1
  74ifeq ($(openssl_available),yes)
  75$(if $(findstring id-ecPublicKey,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem"))
  76endif
  77endif # CONFIG_MODULE_SIG_KEY_TYPE_ECDSA
  78
  79ifdef CONFIG_MODULE_SIG_KEY_TYPE_RSA
  80ifeq ($(openssl_available),yes)
  81$(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem"))
  82endif
  83endif # CONFIG_MODULE_SIG_KEY_TYPE_RSA
  84
  85$(obj)/signing_key.pem: $(obj)/x509.genkey
  86        @$(kecho) "###"
  87        @$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
  88        @$(kecho) "###"
  89        @$(kecho) "### If this takes a long time, you might wish to run rngd in the"
  90        @$(kecho) "### background to keep the supply of entropy topped up.  It"
  91        @$(kecho) "### needs to be run as root, and uses a hardware random"
  92        @$(kecho) "### number generator if one is available."
  93        @$(kecho) "###"
  94        $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
  95                -batch -x509 -config $(obj)/x509.genkey \
  96                -outform PEM -out $(obj)/signing_key.pem \
  97                -keyout $(obj)/signing_key.pem \
  98                $(keytype_openssl) \
  99                $($(quiet)redirect_openssl)
 100        @$(kecho) "###"
 101        @$(kecho) "### Key pair generated."
 102        @$(kecho) "###"
 103
 104$(obj)/x509.genkey:
 105        @$(kecho) Generating X.509 key generation config
 106        @echo  >$@ "[ req ]"
 107        @echo >>$@ "default_bits = 4096"
 108        @echo >>$@ "distinguished_name = req_distinguished_name"
 109        @echo >>$@ "prompt = no"
 110        @echo >>$@ "string_mask = utf8only"
 111        @echo >>$@ "x509_extensions = myexts"
 112        @echo >>$@
 113        @echo >>$@ "[ req_distinguished_name ]"
 114        @echo >>$@ "#O = Unspecified company"
 115        @echo >>$@ "CN = Build time autogenerated kernel key"
 116        @echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
 117        @echo >>$@
 118        @echo >>$@ "[ myexts ]"
 119        @echo >>$@ "basicConstraints=critical,CA:FALSE"
 120        @echo >>$@ "keyUsage=digitalSignature"
 121        @echo >>$@ "subjectKeyIdentifier=hash"
 122        @echo >>$@ "authorityKeyIdentifier=keyid"
 123endif # CONFIG_MODULE_SIG_KEY
 124
 125$(eval $(call config_filename,MODULE_SIG_KEY))
 126
 127# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
 128ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
 129X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
 130endif
 131
 132# GCC PR#66871 again.
 133$(obj)/system_certificates.o: $(obj)/signing_key.x509
 134
 135targets += signing_key.x509
 136$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
 137        $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
 138endif # CONFIG_MODULE_SIG
 139
 140ifeq ($(CONFIG_SYSTEM_REVOCATION_LIST),y)
 141
 142$(eval $(call config_filename,SYSTEM_REVOCATION_KEYS))
 143
 144$(obj)/revocation_certificates.o: $(obj)/x509_revocation_list
 145
 146quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
 147      cmd_extract_certs  = scripts/extract-cert $(2) $@
 148
 149targets += x509_revocation_list
 150$(obj)/x509_revocation_list: scripts/extract-cert $(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(SYSTEM_REVOCATION_KEYS_FILENAME) FORCE
 151        $(call if_changed,extract_certs,$(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_REVOCATION_KEYS))
 152endif
 153