From ea0b6dcf71d216dc11733ac19b26df0f5d0fd6c2 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 26 Sep 2012 10:09:50 +0100 Subject: MODSIGN: Provide Kconfig options Provide kernel configuration options for module signing. The following configuration options are added: CONFIG_MODULE_SIG_SHA1 CONFIG_MODULE_SIG_SHA224 CONFIG_MODULE_SIG_SHA256 CONFIG_MODULE_SIG_SHA384 CONFIG_MODULE_SIG_SHA512 These select the cryptographic hash used to digest the data prior to signing. Additionally, the crypto module selected will be built into the kernel as it won't be possible to load it as a module without incurring a circular dependency when the kernel tries to check its signature. Signed-off-by: David Howells Signed-off-by: Rusty Russell --- init/Kconfig | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index fa8ccad1ea43..00d45799dee1 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1593,12 +1593,50 @@ config MODULE_SIG is simply appended to the module. For more information see Documentation/module-signing.txt. + !!!WARNING!!! If you enable this option, you MUST make sure that the + module DOES NOT get stripped after being signed. This includes the + debuginfo strip done by some packagers (such as rpmbuild) and + inclusion into an initramfs that wants the module size reduced. + config MODULE_SIG_FORCE bool "Require modules to be validly signed" depends on MODULE_SIG help Reject unsigned modules or signed modules for which we don't have a key. Without this, such modules will simply taint the kernel. + +choice + prompt "Which hash algorithm should modules be signed with?" + depends on MODULE_SIG + help + This determines which sort of hashing algorithm will be used during + signature generation. This algorithm _must_ be built into the kernel + directly so that signature verification can take place. It is not + possible to load a signed module containing the algorithm to check + the signature on that module. + +config MODULE_SIG_SHA1 + bool "Sign modules with SHA-1" + select CRYPTO_SHA1 + +config MODULE_SIG_SHA224 + bool "Sign modules with SHA-224" + select CRYPTO_SHA256 + +config MODULE_SIG_SHA256 + bool "Sign modules with SHA-256" + select CRYPTO_SHA256 + +config MODULE_SIG_SHA384 + bool "Sign modules with SHA-384" + select CRYPTO_SHA512 + +config MODULE_SIG_SHA512 + bool "Sign modules with SHA-512" + select CRYPTO_SHA512 + +endchoice + endif # MODULES config INIT_ALL_POSSIBLE -- cgit v1.2.3-59-g8ed1b