Re: [PATCH v3 0/4] IMA: verify measurement of certificate imported into a keyring

Petr Vorel
2020-08-17T20:39:54Z

> On 8/17/20 12:18 PM, Mimi Zohar wrote:

> > On Mon, 2020-08-17 at 15:09 +0200, Petr Vorel wrote:
> > > Hi Mimi, Lakshmi,

> > > changes v2->v3:
> > > fixed regression in my third commit.
> > > (please verify it on installed LTP, or at least run make install in
> > > testcases/kernel/security/integrity/ima/datafiles/ima_keys/)

> > I did, but nothing changed. I probably need to set an environment
> > variable.

> > After building and installing LTP, it's finding the file, but some of
> > the issues still exist:

> > ima_keys 1 TINFO: $TMPDIR is on tmpfs => run on loop device
> > ima_keys 1 TINFO: Formatting /dev/loop0 with ext3 extra opts=''
> > ima_keys 1 TINFO: verify key measurement for keyrings and templates specified in IMA policy
> > grep: Unmatched ( or \(
> > ima_keys 1 TPASS: specified keyrings were measured correctly
> > ima_keys 2 TINFO: verify measurement of certificate imported into a keyring
> > keyctl_session_to_parent: Operation not permitted
> > ima_keys 2 TPASS: logged certificate matches the original

> > IMA policy:
> > measure func=KEY_CHECK keyrings=.ima|.evm|.builtin_trusted_keys|.blacklist|key_import_test template=ima-buf
> > measure func=KEY_CHECK keyrings=key_import_test template=ima-buf

> I think I see the problem

> keyrings=$(for i in $keycheck_lines; do echo "$i" | grep "keyrings" | \
> sed "s/\./\\\./g" | cut -d'=' -f2; done | sort -u

> The above line generates the list of keyrings (read from the IMA policy)
> with a newline after the first policy entry with "keyrings=". Please see
> below:

> ima_keys 1 TINFO: \.ima|\.builtin_trusted_keys
> key_import_test

> When this is checked in the "do-done" loop grep returns "mismatched (" due
> to the newline.

> I tried with "(" removed from the following line and that fixes the problem:

> grep -E "($templates)*($keyrings)" $ASCII_MEASUREMENTS | while read line

> But a better fix might be to remove the "newline" in $keyrings. I'll try
> that.
OK, I was too aggressive when removing tr dependency. I'll add another sed
command to remove new lines.

> Regarding the following error:
> keyctl_session_to_parent: Operation not permitted
I missed this problem.

> The following line in test2() can be removed. Not sure if this is needed.
> keyctl new_session > /dev/null
Not sure, I guess it'd work in existing session. But then it'd be good to
do cleanup.

> thanks,
> -lakshmi

Kind regards,
Petr