man: update --tpm2-device-key= docs to reference the new ways to get the SRK

This commit is contained in:
Lennart Poettering 2023-11-08 22:36:28 +01:00
parent d30693f39b
commit 342c70da7c

View file

@ -444,15 +444,21 @@
enrollment is calculated using the provided TPM2 key. This is useful in situations where the TPM2
security chip is not available at the time of enrollment.</para>
<para>The key, in most cases, should be the Storage Root Key (SRK) from the TPM2 security chip. If a
key from a different handle (not the SRK) is used, you must specify its handle index using
<para>The key, in most cases, should be the Storage Root Key (SRK) from a local TPM2 security
chip. If a key from a different handle (not the SRK) is used, you must specify its handle index using
<option>--tpm2-seal-key-handle=</option>.</para>
<para>You may use tpm2-tss tools to get the SRK from the TPM2 security chip with <citerefentry
project='mankier'><refentrytitle>tpm2_readpublic</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
for example:</para>
<para>The
<citerefentry><refentrytitle>systemd-tpm2-setup.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
service writes the SRK to <filename>/run/systemd/tpm2-srk-public-key.tpm2b_public</filename>
automatically during boot, in the correct format.</para>
<programlisting>tpm2_readpublic -c 0x81000001 -o srk.pub</programlisting>
<para>Alternatively, you may use <command>systemd-analyze srk</command> to retrieve the SRK from the
TPM2 security chip explicitly. See
<citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
for details. Example:</para>
<programlisting>systemd-analyze srk &gt; srk.tpm2b_public</programlisting>
<xi:include href="version-info.xml" xpointer="v255"/></listitem>
</varlistentry>