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-rw-r--r--certs/Makefile129
1 files changed, 129 insertions, 0 deletions
diff --git a/certs/Makefile b/certs/Makefile
new file mode 100644
index 000000000..b338799c0
--- /dev/null
+++ b/certs/Makefile
@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel signature checking certificates.
+#
+
+obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o common.o
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o common.o
+obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o
+ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
+else
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
+endif
+
+ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
+
+$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
+
+# GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
+$(obj)/system_certificates.o: $(obj)/x509_certificate_list
+
+# Cope with signing_key.x509 existing in $(srctree) not $(objtree)
+AFLAGS_system_certificates.o := -I$(srctree)
+
+quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2))
+ cmd_extract_certs = scripts/extract-cert $(2) $@
+
+targets += x509_certificate_list
+$(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
+ $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
+endif # CONFIG_SYSTEM_TRUSTED_KEYRING
+
+clean-files := x509_certificate_list .x509.list x509_revocation_list
+
+ifeq ($(CONFIG_MODULE_SIG),y)
+###############################################################################
+#
+# If module signing is requested, say by allyesconfig, but a key has not been
+# supplied, then one will need to be generated to make sure the build does not
+# fail and that the kernel may be used afterwards.
+#
+###############################################################################
+ifndef CONFIG_MODULE_SIG_HASH
+$(error Could not determine digest type to use from kernel config)
+endif
+
+redirect_openssl = 2>&1
+quiet_redirect_openssl = 2>&1
+silent_redirect_openssl = 2>/dev/null
+openssl_available = $(shell openssl help 2>/dev/null && echo yes)
+
+# We do it this way rather than having a boolean option for enabling an
+# external private key, because 'make randconfig' might enable such a
+# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
+ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
+
+ifeq ($(openssl_available),yes)
+X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null)
+
+$(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem"))
+endif
+
+$(obj)/signing_key.pem: $(obj)/x509.genkey
+ @$(kecho) "###"
+ @$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
+ @$(kecho) "###"
+ @$(kecho) "### If this takes a long time, you might wish to run rngd in the"
+ @$(kecho) "### background to keep the supply of entropy topped up. It"
+ @$(kecho) "### needs to be run as root, and uses a hardware random"
+ @$(kecho) "### number generator if one is available."
+ @$(kecho) "###"
+ $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
+ -batch -x509 -config $(obj)/x509.genkey \
+ -outform PEM -out $(obj)/signing_key.pem \
+ -keyout $(obj)/signing_key.pem \
+ $($(quiet)redirect_openssl)
+ @$(kecho) "###"
+ @$(kecho) "### Key pair generated."
+ @$(kecho) "###"
+
+$(obj)/x509.genkey:
+ @$(kecho) Generating X.509 key generation config
+ @echo >$@ "[ req ]"
+ @echo >>$@ "default_bits = 4096"
+ @echo >>$@ "distinguished_name = req_distinguished_name"
+ @echo >>$@ "prompt = no"
+ @echo >>$@ "string_mask = utf8only"
+ @echo >>$@ "x509_extensions = myexts"
+ @echo >>$@
+ @echo >>$@ "[ req_distinguished_name ]"
+ @echo >>$@ "#O = Unspecified company"
+ @echo >>$@ "CN = Build time autogenerated kernel key"
+ @echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
+ @echo >>$@
+ @echo >>$@ "[ myexts ]"
+ @echo >>$@ "basicConstraints=critical,CA:FALSE"
+ @echo >>$@ "keyUsage=digitalSignature"
+ @echo >>$@ "subjectKeyIdentifier=hash"
+ @echo >>$@ "authorityKeyIdentifier=keyid"
+endif # CONFIG_MODULE_SIG_KEY
+
+$(eval $(call config_filename,MODULE_SIG_KEY))
+
+# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
+ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
+X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
+endif
+
+# GCC PR#66871 again.
+$(obj)/system_certificates.o: $(obj)/signing_key.x509
+
+targets += signing_key.x509
+$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
+ $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
+endif # CONFIG_MODULE_SIG
+
+ifeq ($(CONFIG_SYSTEM_REVOCATION_LIST),y)
+
+$(eval $(call config_filename,SYSTEM_REVOCATION_KEYS))
+
+$(obj)/revocation_certificates.o: $(obj)/x509_revocation_list
+
+quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2))
+ cmd_extract_certs = scripts/extract-cert $(2) $@
+
+targets += x509_revocation_list
+$(obj)/x509_revocation_list: scripts/extract-cert $(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(SYSTEM_REVOCATION_KEYS_FILENAME) FORCE
+ $(call if_changed,extract_certs,$(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_REVOCATION_KEYS))
+endif