modsign: Use single PEM file for autogenerated key

The current rule for generating signing_key.priv and signing_key.x509 is
a classic example of a bad rule which has a tendency to break parallel
make. When invoked to create *either* target, it generates the other
target as a side-effect that make didn't predict.

So let's switch to using a single file signing_key.pem which contains
both key and certificate. That matches what we do in the case of an
external key specified by CONFIG_MODULE_SIG_KEY anyway, so it's also
slightly cleaner.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Woodhouse 2015-07-20 21:16:30 +01:00 committed by David Howells
parent 1329e8cc69
commit fb11794991
5 changed files with 16 additions and 17 deletions

1
.gitignore vendored
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@ -97,6 +97,7 @@ GTAGS
# Leavings from module signing
#
extra_certificates
signing_key.pem
signing_key.priv
signing_key.x509
x509.genkey

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@ -91,7 +91,7 @@ This has a number of options available:
(4) "File name or PKCS#11 URI of module signing key" (CONFIG_MODULE_SIG_KEY)
Setting this option to something other than its default of
"signing_key.priv" will disable the autogeneration of signing keys and
"signing_key.pem" will disable the autogeneration of signing keys and
allow the kernel modules to be signed with a key of your choosing.
The string provided should identify a file containing both a private
key and its corresponding X.509 certificate in PEM form, or — on
@ -116,11 +116,10 @@ kernel so that it can be used to check the signatures as the modules are
loaded.
Under normal conditions, when CONFIG_MODULE_SIG_KEY is unchanged from its
default of "signing_key.priv", the kernel build will automatically generate
a new keypair using openssl if one does not exist in the files:
default, the kernel build will automatically generate a new keypair using
openssl if one does not exist in the file:
signing_key.priv
signing_key.x509
signing_key.pem
during the building of vmlinux (the public part of the key needs to be built
into vmlinux) using parameters in the:

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@ -1173,8 +1173,8 @@ MRPROPER_DIRS += include/config usr/include include/generated \
arch/*/include/generated .tmp_objdiff
MRPROPER_FILES += .config .config.old .version .old_version \
Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
signing_key.priv signing_key.x509 x509.genkey \
extra_certificates signing_key.x509.keyid \
signing_key.pem signing_key.priv signing_key.x509 \
x509.genkey extra_certificates signing_key.x509.keyid \
signing_key.x509.signer vmlinux-gdb.py
# clean - Delete most, but leave enough to build external modules

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@ -1950,7 +1950,7 @@ config MODULE_SIG_HASH
config MODULE_SIG_KEY
string "File name or PKCS#11 URI of module signing key"
default "signing_key.priv"
default "signing_key.pem"
depends on MODULE_SIG
help
Provide the file name of a private key/certificate in PEM format,
@ -1958,7 +1958,7 @@ config MODULE_SIG_KEY
the URI should identify, both the certificate and its corresponding
private key.
If this option is unchanged from its default "signing_key.priv",
If this option is unchanged from its default "signing_key.pem",
then the kernel will automatically generate the private key and
certificate as described in Documentation/module-signing.txt

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@ -173,8 +173,8 @@ endif
# 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 ($(CONFIG_MODULE_SIG_KEY),"signing_key.priv")
signing_key.priv signing_key.x509: x509.genkey
ifeq ($(CONFIG_MODULE_SIG_KEY),"signing_key.pem")
signing_key.pem: x509.genkey
@echo "###"
@echo "### Now generating an X.509 key pair to be used for signing modules."
@echo "###"
@ -185,8 +185,8 @@ signing_key.priv signing_key.x509: x509.genkey
@echo "###"
openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
-batch -x509 -config x509.genkey \
-outform DER -out signing_key.x509 \
-keyout signing_key.priv 2>&1
-outform PEM -out signing_key.pem \
-keyout signing_key.pem 2>&1
@echo "###"
@echo "### Key pair generated."
@echo "###"
@ -210,9 +210,9 @@ x509.genkey:
@echo >>x509.genkey "keyUsage=digitalSignature"
@echo >>x509.genkey "subjectKeyIdentifier=hash"
@echo >>x509.genkey "authorityKeyIdentifier=keyid"
else
# For external (PKCS#11 or PEM) key, we need to obtain the certificate from
# CONFIG_MODULE_SIG_KEY automatically.
endif
# We need to obtain the certificate from CONFIG_MODULE_SIG_KEY.
quiet_cmd_extract_der = CERT_DER $(2)
cmd_extract_der = scripts/extract-cert "$(2)" signing_key.x509
@ -249,4 +249,3 @@ endif
signing_key.x509: scripts/extract-cert include/config/module/sig/key.h $(X509_DEP)
$(call cmd,extract_der,$(X509_SOURCE))
endif
endif