[tpm2] Re: Is the tpm2_create command safe against sniffing attacks?
Kenneth Goldman <kgoldman at us.ibm.com>
| Newsgroups | dev.linux.lists.tpm2 |
|---|---|
| Message-ID | <OF8BBF26A9.0B99F84B-ON00258725.00602982-85258725.006843B9@ibm.com> |
"Steven Clark" <davolfman(a)gmail.com> wrote on 08/02/2021 01:26:56 PM: > I think it may be an optional standard but my TPM has some certs > permanently stored in nv-indices in the 0x1c0000x range that can be > checked against the manufacturer cert. I haven't learned how to > leverage those into trusted parameter encryption keys yet but they > should be able to verify there's a real TPM at the other end at the > very least (and more if you learn to use them correctly). The EK certificates in NV are in theory optional, but every TPM I have encountered has them. Checking the certificate against the manufacturer's CA is a standard crypto library function. Once you have an authentic EK, create a salted session using the EK. Once you have the salted session, set the encrypt and/or decrypt bit when running the command. Underneath, there's some complicated crypto, but it's all hidden from the application.
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<html><body><p><tt><font size="2">"Steven Clark" <[email protected]> wrote on 08/02/2021 01:26:56 PM:<br><br>> I think it may be an optional standard but my TPM has some certs <br>> permanently stored in nv-indices in the 0x1c0000x range that can be <br>> checked against the manufacturer cert. I haven't learned how to <br>> leverage those into trusted parameter encryption keys yet but they <br>> should be able to verify there's a real TPM at the other end at the <br>> very least (and more if you learn to use them correctly).</font></tt><br><tt><font size="2"><br>The EK certificates in NV are in theory optional, but every TPM</font></tt><br><tt><font size="2">I have encountered has them.</font></tt><br><br><tt><font size="2">Checking the certificate against the manufacturer's CA is</font></tt><br><tt><font size="2">a standard crypto library function.</font></tt><br><br><tt><font size="2">Once you have an authentic EK, create a salted session using</font></tt><br><tt><font size="2">the EK.</font></tt><br><br><tt><font size="2">Once you have the salted session, set the encrypt and/or decrypt bit</font></tt><br><tt><font size="2">when running the command.</font></tt><br><br><tt><font size="2">Underneath, there's some complicated crypto, but it's all</font></tt><br><tt><font size="2">hidden from the application.</font></tt><BR> <BR> </body></html>