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