Re: [RFC 1/1] ima: digital signature verification using asymmetric keys

[Mimi Zohar <zohar@linux.vnet.ibm.com>]

On Mon, 2013-01-28 at 13:56 -0500, Vivek Goyal wrote:
> On Mon, Jan 28, 2013 at 05:20:20PM +0200, Kasatkin, Dmitry wrote:
> 
> [..]
> > > Ok. I am hoping that it will be more than the kernel command line we
> > > support. In the sense that for digital signatures one needs to parse
> > > the signature, look at what hash algorithm has been used  and then
> > > collect the hash accordingly. It is little different then IMA requirement
> > > of calculating one pre-determine hash for all files.
> > 
> > Yes... It is obvious. It's coming.
> > But in general, signer should be aware of requirements and limitation
> > of the platform.
> > It is not really a problem...
> 
> One more question. I specified "ima_appraise_tcb" on kernel command line
> and I had an unbootable system. It refused to run "init" as it was not
> labeled/signed. Is there any policy/way where it appraises only signed
> files and does not refuse to open/execute unsigned ones.

The policy defines what needs to be measured/appraised, not the other
way around.  There's nothing preventing you from defining and loading a
different policy, one to your liking, before pivoting root.

thanks,

Mimi