Messages in this thread | | | Subject | Re: [PATCH 01/11] evm: Execute evm_inode_init_security() only when the HMAC key is loaded | From | Mimi Zohar <> | Date | Wed, 02 Sep 2020 09:40:51 -0400 |
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On Wed, 2020-09-02 at 11:42 +0000, Roberto Sassu wrote: > > From: Mimi Zohar [mailto:zohar@linux.ibm.com] > > Sent: Monday, August 24, 2020 7:45 PM > > Hi Roberto, > > > > On Fri, 2020-08-21 at 14:30 -0400, Mimi Zohar wrote: > > > Sorry for the delay in reviewing these patches. Missing from this > > > patch set is a cover letter with an explanation for grouping these > > > patches into a patch set, other than for convenience. In this case, it > > > would be along the lines that the original use case for EVM portable > > > and immutable keys support was for a few critical files, not combined > > > with an EVM encrypted key type. This patch set more fully integrates > > > the initial EVM portable and immutable signature support. > > > > Thank you for more fully integrating the EVM portable signatures into > > IMA. > > > > " [PATCH 08/11] ima: Allow imasig requirement to be satisfied by EVM > > portable signatures" equates an IMA signature to having a portable and > > immutable EVM signature. That is true in terms of signature > > verification, but from an attestation perspective the "ima-sig" > > template will not contain a signature. If not the EVM signature, then > > at least some other indication should be included in the measurement > > list. > > Would it be ok to print the EVM portable signature in the sig field if the IMA > signature is not found? Later we can introduce the new template evm-sig > to include all metadata necessary to verify the EVM portable signature.
As long as the attestation server can differentiate between the signature types, including the EVM signature should be fine.
> > > Are you planning on posting the associated IMA/EVM regression tests? > > I didn't have a look yet at the code. I will try to write some later.
It looks like ima_verify_signature() in ima-evm-utils could be extended to support the EVM portable signature or at least not to fail the signature verification.
Mimi
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