<p>Script and instruction at<br />
<a href="https://james.toebesacademy.com/USBKey.html" class="uri">https://james.toebesacademy.com/USBKey.html</a></p>
<ul>
<li>Combo of
<ul>
<li>Perl for Installation,</li>
<li><code>ssh-keygen</code> for key exchange.</li>
<li><code>udev</code> for actions</li>
<li><code>bash</code> for locking/unlocking/key checking.</li>
</ul></li>
</ul>
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<ul>
<li><code>udev</code> add/remove/change events
<ul>
<li>add event does not allow access to drive</li>
<li>change event was not allowing unlock.</li>
</ul></li>
</ul>
<p>Compromise was <em>unlock</em>, then <em>lock</em> if key check fails.</p>
