[PATCH v5,4/4] Documentation/admin-guide/module-signing.rst: add openssl command option example for CodeSign EKU

From: Lee, Chun-Yi
Date: Mon Apr 12 2021 - 00:47:52 EST


Add an openssl command option example for generating CodeSign extended
key usage in X.509 when CONFIG_CHECK_CODESIGN_EKU is enabled.

Signed-off-by: "Lee, Chun-Yi" <jlee@xxxxxxxx>
---
Documentation/admin-guide/module-signing.rst | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/admin-guide/module-signing.rst b/Documentation/admin-guide/module-signing.rst
index 7d7c7c8a545c..ca3b8f19466c 100644
--- a/Documentation/admin-guide/module-signing.rst
+++ b/Documentation/admin-guide/module-signing.rst
@@ -170,6 +170,12 @@ generate the public/private key files::
-config x509.genkey -outform PEM -out kernel_key.pem \
-keyout kernel_key.pem

+When ``CONFIG_CHECK_CODESIGN_EKU`` option is enabled, the following openssl
+command option should be added where for generating CodeSign extended key usage
+in X.509::
+
+ -addext "extendedKeyUsage=codeSigning"
+
The full pathname for the resulting kernel_key.pem file can then be specified
in the ``CONFIG_MODULE_SIG_KEY`` option, and the certificate and key therein will
be used instead of an autogenerated keypair.
--
2.16.4