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$(error Could not determine digest type to use from kernel config) 55endif 56 57redirect_openssl = 2>&1 58quiet_redirect_openssl = 2>&1 59silent_redirect_openssl = 2>/dev/null 60 61# We do it this way rather than having a boolean option for enabling an 62# external private key, because 'make randconfig' might enable such a 63# boolean option and we unfortunately can't make it depend on !RANDCONFIG. 64ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem") 65$(obj)/signing_key.pem: $(obj)/x509.genkey 66 @$(kecho) "###" 67 @$(kecho) "### Now generating an X.509 key pair to be used for signing modules." 68 @$(kecho) "###" 69 @$(kecho) "### If this takes a long time, you might wish to run rngd in the" 70 @$(kecho) "### background to keep the supply of entropy topped up. It" 71 @$(kecho) "### needs to be run as root, and uses a hardware random" 72 @$(kecho) "### number generator if one is available." 73 @$(kecho) "###" 74 $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \ 75 -batch -x509 -config $(obj)/x509.genkey \ 76 -outform PEM -out $(obj)/signing_key.pem \ 77 -keyout $(obj)/signing_key.pem \ 78 $($(quiet)redirect_openssl) 79 @$(kecho) "###" 80 @$(kecho) "### Key pair generated." 81 @$(kecho) "###" 82 83$(obj)/x509.genkey: 84 @$(kecho) Generating X.509 key generation config 85 @echo >$@ "[ req ]" 86 @echo >>$@ "default_bits = 4096" 87 @echo >>$@ "distinguished_name = req_distinguished_name" 88 @echo >>$@ "prompt = no" 89 @echo >>$@ "string_mask = utf8only" 90 @echo >>$@ "x509_extensions = myexts" 91 @echo >>$@ 92 @echo >>$@ "[ req_distinguished_name ]" 93 @echo >>$@ "#O = Unspecified company" 94 @echo >>$@ "CN = Build time autogenerated kernel key" 95 @echo >>$@ "#emailAddress = unspecified.user@unspecified.company" 96 @echo >>$@ 97 @echo >>$@ "[ myexts ]" 98 @echo >>$@ "basicConstraints=critical,CA:FALSE" 99 @echo >>$@ "keyUsage=digitalSignature" 100 @echo >>$@ "subjectKeyIdentifier=hash" 101 @echo >>$@ "authorityKeyIdentifier=keyid" 102endif # CONFIG_MODULE_SIG_KEY 103 104$(eval $(call config_filename,MODULE_SIG_KEY)) 105 106# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it 107ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME))) 108X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME) 109endif 110 111# GCC PR#66871 again. 112$(obj)/system_certificates.o: $(obj)/signing_key.x509 113 114targets += signing_key.x509 115$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE 116 $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY)) 117endif # CONFIG_MODULE_SIG 118 119ifeq ($(CONFIG_SYSTEM_REVOCATION_LIST),y) 120 121$(eval $(call config_filename,SYSTEM_REVOCATION_KEYS)) 122 123$(obj)/revocation_certificates.o: $(obj)/x509_revocation_list 124 125quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2)) 126 cmd_extract_certs = scripts/extract-cert $(2) $@ 127 128targets += x509_revocation_list 129$(obj)/x509_revocation_list: scripts/extract-cert $(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(SYSTEM_REVOCATION_KEYS_FILENAME) FORCE 130 $(call if_changed,extract_certs,$(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_REVOCATION_KEYS)) 131endif 132