[tpm2] Re: Clearing TPM
Steven Clark <davolfman at gmail.com> Fri, 30 Sep 2022 13:07:53 -0700
| Newsgroups | dev.linux.lists.tpm2 |
|---|---|
| Message-ID | <CAOCvsSnLQRZOkvo=yey3w6XtL17TKo7A9C1kY=eGFj+wvZ9o1Q@mail.gmail.com> |
Also there's the Physical Presence Interface if your device supports it. You echo a number representing the type of reset you want to the sysfs path at /sys/class/tpm/tpm0/ppi/request, read out the success or failure at /sys/class/tpm/tpm0/ppi/response and reboot. The BIOS then uses it's platform authority to issue a clear, usually after prompting you to press some key to indicate you're at the console and agree. For example: $echo 5 > /sys/class/tpm/tpm0/ppi/request $reboot On Fri, Sep 30, 2022, 12:50 PM Roberts, William C < william.c.roberts(a)intel.com> wrote: > On Fri, 2022-09-30 at 17:46 +0000, burnsds.accounts(a)protonmail.com > wrote: > > Is there any way to get out of this state without the lockout > > password? > > Platform auth, which you won't have as its typically randomly set by > the OS on boot or you can use the bios settings to clear an Intel or > AMD based TPM. For discrete TPMs you need to consult their manuals. > Typically, its playing with some jumpers. > > > _______________________________________________ > > tpm2 mailing list -- tpm2(a)lists.01.org > > To unsubscribe send an email to tpm2-leave(a)lists.01.org > > %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s > _______________________________________________ > tpm2 mailing list -- tpm2(a)lists.01.org > To unsubscribe send an email to tpm2-leave(a)lists.01.org > %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s >
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<div dir="auto">Also there's the Physical Presence Interface if your device supports it. You echo a number representing the type of reset you want to the sysfs path at /sys/class/tpm/tpm0/ppi/request, read out the success or failure at /sys/class/tpm/tpm0/ppi/response and reboot. The BIOS then uses it's platform authority to issue a clear, usually after prompting you to press some key to indicate you're at the console and agree.<div dir="auto"><br></div><div dir="auto">For example:</div><div dir="auto">$echo 5 > /sys/class/tpm/tpm0/ppi/request</div><div dir="auto">$reboot</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Sep 30, 2022, 12:50 PM Roberts, William C <<a href="mailto:[email protected]">[email protected]</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Fri, 2022-09-30 at 17:46 +0000, <a href="mailto:[email protected]" target="_blank" rel="noreferrer">[email protected]</a><br> wrote:<br> > Is there any way to get out of this state without the lockout<br> > password?<br> <br> Platform auth, which you won't have as its typically randomly set by<br> the OS on boot or you can use the bios settings to clear an Intel or<br> AMD based TPM. For discrete TPMs you need to consult their manuals.<br> Typically, its playing with some jumpers. <br> <br> > _______________________________________________<br> > tpm2 mailing list -- <a href="mailto:[email protected]" target="_blank" rel="noreferrer">[email protected]</a><br> > To unsubscribe send an email to <a href="mailto:[email protected]" target="_blank" rel="noreferrer">[email protected]</a><br> > %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s<br> _______________________________________________<br> tpm2 mailing list -- <a href="mailto:[email protected]" target="_blank" rel="noreferrer">[email protected]</a><br> To unsubscribe send an email to <a href="mailto:[email protected]" target="_blank" rel="noreferrer">[email protected]</a><br> %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s<br> </blockquote></div>