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