Messages in this thread | | | Subject | Re: [PATCH v3 4/5] LSM: Define SELinux function to measure security state | From | Lakshmi Ramasubramanian <> | Date | Mon, 20 Jul 2020 11:59:51 -0700 |
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On 7/20/20 11:44 AM, Stephen Smalley wrote:
>>> >>> Actually, if we used ima-ng template for selinux-policy-hash, then >>> instead of needing to hash the policy >>> first and passing the hash to IMA, we could just pass the policy as >>> the buffer and IMA would take care of the hashing, right? >> >> That is correct. >> >> The IMA hook I've added to measure LSM structures is a generic one that >> can be used by any security module (SM). I feel it would be better to >> not have policy or state or any such SM specific logic in IMA, but leave >> that to the individual SM to handle. >> >> What do you think? > > It is correct to remain security module agnostic. However, I think > you can remain LSM-neutral while still avoiding the double hashing of > the policy here. Can't you just pass in the policy itself as the > buffer and let IMA hash it?
Yes - that is an option. If I do that then, as you have stated below, we'll need to two funcs - one that will only add the hash but not the entire data payload in the IMA log (i.e., "ima-ng") and, the other that handles hashing and including date payload (i.e., "ima-buf").
Then you can let the policy author decide > on the template to be used (ima-buf versus ima-ng). If you want to > support the use of different templates for different "kinds" of LSM > state (e.g. state versus policy) you could either provide two funcs > (LSM_STATE, LSM_POLICY) or otherwise support selection based on some > other attribute. >
I can do the above.
-lakshmi
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