Re: [gentoo-dev] [PATCH] linux-mod.eclass: support module signing

[Kenton Groombridge]

On 22/06/21 02:19PM, Kenton Groombridge wrote:
> eee74b9fca1 adds support for module compression, but this breaks loading
> out of tree modules when module signing is enforced because modules must
> be signed before they are compressed. Additionally, the recommended
> Portage hook[1] no longer works with this change.
>

Forgot to include this reference:

[1] https://wiki.gentoo.org/wiki/Signed_kernel_module_support#Automatically_signing_kernel_modules_.28Portage.29

> Add module signing support in linux-mod.eclass which more or less does
> exactly what the aforementioned Portage hook does. If the kernel
> configuration has CONFIG_MODULE_SIG_ALL=y, then read the hash and keys
> from the kernel configuration and call the sign_file tool to sign the
> module before it is compressed.
>
> Bug: https://bugs.gentoo.org/show_bug.cgi?id=447352
> Signed-off-by: Kenton Groombridge <concord@g.o>
> ---
>  eclass/linux-mod.eclass | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/eclass/linux-mod.eclass b/eclass/linux-mod.eclass
> index b7c13cbf7e7..fd40f6d7c6c 100644
> --- a/eclass/linux-mod.eclass
> +++ b/eclass/linux-mod.eclass
> @@ -712,6 +712,22 @@ linux-mod_src_install() {
>  		cd "${objdir}" || die "${objdir} does not exist"
>  		insinto "${INSTALL_MOD_PATH}"/lib/modules/${KV_FULL}/${libdir}
>
> +		# check here for CONFIG_MODULE_SIG_ALL and sign the module being built if enabled.
> +		# modules must be signed before they are compressed.
> +
> +		if linux_chkconfig_present MODULE_SIG_ALL; then
> +			local module_sig_hash="$(linux_chkconfig_string MODULE_SIG_HASH)"
> +			local module_sig_key="$(linux_chkconfig_string MODULE_SIG_KEY)"
> +			module_sig_key="${module_sig_key:-certs/signing_key.pem}"
> +			if [[ "${module_sig_key#pkcs11:}" == "${module_sig_key}" && "${module_sig_key#/}" == "${module_sig_key}" ]]; then
> +				local key_path="${KERNEL_DIR}/${module_sig_key}"
> +			else
> +				local key_path="${module_sig_key}"
> +			fi
> +			local cert_path="${KERNEL_DIR}/certs/signing_key.x509"
> +			"${KERNEL_DIR}"/scripts/sign-file ${module_sig_hash//\"} ${key_path//\"} ${cert_path} ${modulename}.${KV_OBJ}
> +		fi
> +
>  		# check here for CONFIG_MODULE_COMPRESS_<compression option> (NONE, GZIP, XZ, ZSTD)
>  		# and similarily compress the module being built if != NONE.
>
> --
> 2.35.1
>
>