On Sat, Apr 23, 2016 at 02:57:55PM +0200, Kevin Kofler wrote: > Matthew Garrett wrote: > > Remote attestation is a mechanism by which […] > > How does the remote machine know that what is answering is a physical TPM > and not a software emulation? Does it need to have the individual TPM's > public key in advance?
If I understood it correctly, the TPM keys can be chained back to a manufacturer key and likely some kind of CA. So while software emulation is unfeasible without the ability to extract private keys from either TPMs or their vendors, you should be able to buy any TPM, feed it with exactly the values you want, and get yourself a signed attestation of TPM state that has no relationship to what is actually running on your computer. That works as long as the other side only verifies against some generic vendor public key. If you precisely know the key the signature should've been made with (e.g. because you did the initial machine setup and then left it with some colocation facility) you can verify it against the expected public key directly. Used this way, remote attestation might actually be useful. -- devel mailing list devel@lists.fedoraproject.org http://lists.fedoraproject.org/admin/lists/devel@lists.fedoraproject.org
