Messages in this thread | | | Subject | Re: [PATCH 1/4] integrity: TPM internel kernel interface | From | Kenneth Goldman <> | Date | Wed, 13 Aug 2008 09:46:24 -0400 |
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Alan Cox <alan@lxorguk.ukuu.org.uk> wrote on 08/12/2008 05:36:36 PM:
> > Being a TCG/TPM person, I can only address the first question. The > > intent is that the TPM is soldered to the planar/motherboard (the TCG > > uses the phrase "bound to the platform"). I can't imagine > > any manufacturer designing a pluggable TPM. It would subvert PCR > > measurements and thus attestation, data sealing, etc. > > So the security limit of your TPM is a soldering iron .. whoo. I'm not > sure this is actually the case however as the secret of interest is in > the TPM so even if I replaced the TPM the goodies already set up are in > the TPM I just unsoldered surely ?
I suppose it depends on the precise interpretation of your technical term "goodies". :-)
One of the two primary uses of the TCG technology is protection against an attack on the software. The TCG uses the terms attestation, integrity, platform measurements, etc. For this class of> "goodies", the TCG technology does not protect against hardware attacks such as replacing the TPM with a bogus device, replacing the CRTM hardware, flashing the CRTM using a JTAG cable, lifting a TPM pin> and asserting reset, using a JTAG cable to set breakpoints and alter memory, etc.
For this use case, the attack model is a remote, software attack. The> user is not considered the attacker.
(In the other primary use case, the user is the attacker, but it's an entirely different discussion.)
(It's also important to note that the TPM itself does not completely secure the platform. There's an entire system design around it, which> it why I try to say "TCG technology" rather than TPM.)
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