Re: [Patch 3/7] integrity: EVM as an integrity service provider

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

On Sun, 2007-03-25 at 21:28 -0800, Andrew Morton wrote:
> On Sun, 25 Mar 2007 23:13:02 -0400 Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> 
> > On Sun, 2007-03-25 at 00:16 -0800, Andrew Morton wrote:
> > > On Fri, 23 Mar 2007 12:09:36 -0400 Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> > > 
> > > > +++ linux-2.6.21-rc4-mm1/security/evm/Kconfig
> > > > @@ -0,0 +1,17 @@
> > > > +config INTEGRITY_EVM
> > > > +	boolean "EVM support"
> > > > +	depends on INTEGRITY && KEYS
> > > > +	select CRYPTO_HMAC
> > > > +	select CRYPTO_MD5
> > > > +	select CRYPTO_SHA1
> > > > +	default 0
> > > > +	help
> > > > +	  The Extended Verification Module is an integrity provider.
> > > > +	  An extensible set of extended attributes, as defined in
> > > > +	  /etc/evm.conf, are HMAC protected against modification
> > > > +	  using the TPM's KERNEL ROOT KEY, if configured, or with a
> > > > +	  pass-phrase.  Possible extended attributes include authenticity,
> > > > +	  integrity, and revision level.
> > > > +
> > > > +	  If you are unsure how to answer this question, answer N.
> > > > +
> > > 
> > > Is no dependency upon TPM needed?
> > 
> > It's obviously preferable to have and use a TPM, but if one is not
> > available you can use a pass-phrase.
> > 
> 
> So it will compile and run OK with CONFIG_TPM=n?  And with
> CONFIG_INTEGRITY_EVM=y, CONFIG_TPM=m?

Sorry, I guess I wasn't clear.  If you are using a TPM, then it 
has to be builtin.  In addition, if you don't enable a TPM, then
you can't enable IMA either.

Mimi