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This is a WIP/Proof-of-Concept change to introduce kernel module signing. The actual signing is performed by the in-tree script sign-file. The private key and the certificate must be provided in the same directory as the libs/ checkout, under a specially created directory signed-key/, i.e. + agent-libs + cmake + driver + proposals + signing-key <----- + test + userspace and must be called: + key.priv (private key in PEM format) + key.der (certificate in DER format) NOTE: this was done in order not to create any additional paths to mount as volume, (first to the outer container, and then to the specific container). ALSO NOTE: on newer kernels the sign-file would be a C program which also accepts a PEM textual file for the certificate but older kernels use a perl script which can only read a DER binary file, so for compatibility reason this _must_ be a binary file. The top-level python script must be called with the '-x/--sign' flag in order for module signing to be enabled. Since different kernels might use a different hashing algorithm (sha256, sha512, etc..), the one chosen by the target kernel is read from the kernel config file under CONFIG_MODULE_SIG_HASH. This value is then passed over to the downstream builder as SIGN_FILE_HASH_ALGO. When '-x/--sign' is not specified, this is left empty and the module is NOT signed.
gnosek
previously approved these changes
Feb 23, 2023
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gnosek
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gnosek
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I'm not 100% thrilled about adding stuff to the agent-libs checkout but I see why you went that way.
LGTM!
nathan-b
approved these changes
Apr 7, 2023
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This is a WIP/Proof-of-Concept change to introduce kernel module signing.
The actual signing is performed by the in-tree script sign-file.
The private key and the certificate must be provided in the same directory as the libs/ checkout, under a specially created directory signed-key/, i.e.
and must be called:
NOTE: this was done in order not to create any additional paths to mount as volume, (first to the outer container, and then to the specific container).
ALSO NOTE: on newer kernels the sign-file would be a C program which also accepts a PEM textual file for the certificate but older kernels use a perl script which can only read a DER binary file, so for compatibility reason this must be a binary file.
The top-level python script must be called with the '-x/--sign' flag in order for module signing to be enabled.
Since different kernels might use a different hashing algorithm (sha256, sha512, etc..), the one chosen by the target kernel is read from the kernel config file under CONFIG_MODULE_SIG_HASH.
This value is then passed over to the downstream builder as SIGN_FILE_HASH_ALGO.
When '-x/--sign' is not specified, this is left empty and the module is NOT signed.