Re: [PATCH v9 6/6] IMA: Read keyrings= option from the IMA policy

[Lakshmi Ramasubramanian]

On 11/27/19 11:32 AM, Mimi Zohar wrote:

> The example is really too colloquial/verbose. ÂPlease truncate it,
> leaving just a sample "key" policy rule, with directions for verifying
> the template data against the digest included in the measurement list.

I'll truncate the example and keep it to the point.

> > The following command verifies if the SHA256 hash generated from
> > the payload in the IMA log entry (listed above) for the .ima key
> > matches the SHA256 hash in the IMA log entry. The output of this
> > command should match the SHA256 hash given in the IMA log entry
> > (In this case, it should be
> > 27c915b8ddb9fae7214cf0a8a7043cc3eeeaa7539bcb136f8427067b5f6c3b7b)
>
> Previously you didn't use the hash value, but ".ima" to locate the
> "key" measurement in the measurement list. ÂIn each of the commands
> above, it might be clearer.

If the IMA measurement list has only one IMA key then locating it with 
".ima" would work - hash won't be needed for locating the entry.

But for describing key verification we can have just one IMA key. I'll 
change the description to locate the entry using ".ima".

> > # cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements
> > | grep
> > 27c915b8ddb9fae7214cf0a8a7043cc3eeeaa7539bcb136f8427067b5f6c3b7b |
>
> > cut -d' ' -f 6 | xxd -r -p |tee ima-cert.der | sha256sum | cut -d' '
> > -f 1
> >
> > The above command also creates a binary file namely ima-cert.der
> > using the payload in the IMA log entry. This file should be a valid
> > x509 certificate which can be verified using openssl as given below:
> >
> > root@nramas:/home/nramas
>
> ditto
>
>
> > # openssl x509 -in ima-cert.der -inform DER -text
> >
> > The above command should display the contents of the file ima-cert.der
> > as an x509 certificate.
>
> Either the comments should be above or below the commands, not both.

I'll update the comment.

> > The IMA policy used here allows measurement of keys added to
> > ".ima" and ".evm" keyrings only. Add a key to any other keyring and
> > verify that the key is not measured.
>
> This comment would be included, if desired, when defining the policy
> rule, not here.

Will remove the above from this patch description.

thanks,
 -lakshmi