From fb1179499134bc718dc7557c7a6a95dc72f224cb Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Mon, 20 Jul 2015 21:16:30 +0100 Subject: [PATCH] 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 Signed-off-by: David Howells --- .gitignore | 1 + Documentation/module-signing.txt | 9 ++++----- Makefile | 4 ++-- init/Kconfig | 4 ++-- kernel/Makefile | 15 +++++++-------- 5 files changed, 16 insertions(+), 17 deletions(-) diff --git a/.gitignore b/.gitignore index 4ad4a98b884b9c..17fa24dd7e4606 100644 --- a/.gitignore +++ b/.gitignore @@ -97,6 +97,7 @@ GTAGS # Leavings from module signing # extra_certificates +signing_key.pem signing_key.priv signing_key.x509 x509.genkey diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt index 6930019208901b..5d5e4e32dc260b 100644 --- a/Documentation/module-signing.txt +++ b/Documentation/module-signing.txt @@ -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: diff --git a/Makefile b/Makefile index 531dd16c97514e..6ab99d8cc23c01 100644 --- a/Makefile +++ b/Makefile @@ -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 diff --git a/init/Kconfig b/init/Kconfig index e2e0a1d27886df..2b119850784bba 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -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 diff --git a/kernel/Makefile b/kernel/Makefile index fa2f8b84b18ab8..7453283981ca8e 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -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