path: root/init
diff options
authorDavid Howells <>2012-09-26 10:09:50 +0100
committerRusty Russell <>2012-10-10 20:01:20 +1030
commitea0b6dcf71d216dc11733ac19b26df0f5d0fd6c2 (patch)
tree2b48610cfa37c0f736ab7e019b0370861f59f93a /init
parentaddbcdbbf549c9127c2bbb39caaa08bb47b996f4 (diff)
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 <>
Diffstat (limited to 'init')
1 files changed, 38 insertions, 0 deletions
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
+ !!!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.
bool "Require modules to be validly signed"
depends on MODULE_SIG
Reject unsigned modules or signed modules for which we don't have a
key. Without this, such modules will simply taint the kernel.
+ 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.
+ 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
endif # MODULES