<h1 id="chatting-wth-sgoti">Chatting wth Sgoti</h1>
<h3 id="sgoti-talks-about-ssh-and-github-">Sgoti talks about SSH and Github.</h3>
<ul>
<li><p><a href="https://man.openbsd.org/ssh_config#PreferredAuthentications">openbsd:</a> PreferredAuthentications \</p>
<ul>
<li><p>Specifies the order in which the client should try authentication methods. \</p>
</li>
<li><p><code>gssapi-with-mic,hostbased,publickey,keyboard-interactive,password</code></p>
</li>
</ul>
</li>
</ul>
<ul>
<li><a href="https://man.openbsd.org/ssh_config#HostKeyAlgorithms">openbsd:</a> HostKeyAlgorithms \</li>
</ul>
<pre><code class="lang-bash">
$ssh -Q HostKeyAlgorithms;


ssh-ed25519

ssh-ed25519-cert-v01@openssh.com

sk-ssh-ed25519@openssh.com

sk-ssh-ed25519-cert-v01@openssh.com

ssh-rsa

rsa-sha2-256

rsa-sha2-512

ssh-dss

ecdsa-sha2-nistp256

ecdsa-sha2-nistp384

ecdsa-sha2-nistp521

sk-ecdsa-sha2-nistp256@openssh.com

webauthn-sk-ecdsa-sha2-nistp256@openssh.com

ssh-rsa-cert-v01@openssh.com

rsa-sha2-256-cert-v01@openssh.com

rsa-sha2-512-cert-v01@openssh.com

ssh-dss-cert-v01@openssh.com

ecdsa-sha2-nistp256-cert-v01@openssh.com

ecdsa-sha2-nistp384-cert-v01@openssh.com

ecdsa-sha2-nistp521-cert-v01@openssh.com

sk-ecdsa-sha2-nistp256-cert-v01@openssh.com
</code></pre>
<ul>
<li><p><a href="https://man.openbsd.org/ssh_config#IdentitiesOnly">openbsd:</a> IdentitiesOnly \</p>
<ul>
<li>Specifies that ssh(1) should only use the configured authentication identity and certificate files (either the default files, or those explicitly configured in the ssh_config files or passed on the ssh(1) command-line), even if ssh-agent(1) or a PKCS11Provider or SecurityKeyProvider offers more identities. The argument to this keyword must be yes or no (the default). This option is intended for situations where ssh-agent offers many different identities. \</li>
</ul>
</li>
</ul>
<p>Sample ssh config. \</p>
<pre><code>
<span class="hljs-meta">#Github Primary Yubikey</span>

Host github

   User git

   HostName github.com

   Port <span class="hljs-number">22</span>

   IdentityFile ~/.ssh/github-yubikey<span class="hljs-number">-0</span>


<span class="hljs-meta">#Github Secondary Yubikey</span>

Host github

   User git

   HostName github.com

   Port <span class="hljs-number">22</span>

   IdentityFile ~/.ssh/github-yubikey<span class="hljs-number">-1</span>


<span class="hljs-meta">#Global properties.</span>

Host *

   PubkeyAuthentication=yes

   PreferredAuthentications=publickey,keyboard-interactive

   PubkeyAcceptedAlgorithms=sk-ssh-ed25519@openssh.com,ssh-ed25519,rsa-sha2<span class="hljs-number">-512</span>


<span class="hljs-meta">#ssh-ed25519</span>

<span class="hljs-meta">#ssh-ed25519-cert-v01@openssh.com</span>

<span class="hljs-meta">#sk-ssh-ed25519@openssh.com</span>

<span class="hljs-meta">#sk-ssh-ed25519-cert-v01@openssh.com</span>

<span class="hljs-meta">#ssh-rsa</span>
</code></pre><pre><code class="lang-bash">
ssh-keygen -t ed25519-sk -C <span class="hljs-string">"user@domain.tld"</span> -f ~<span class="hljs-regexp">/.ssh/gi</span>thub-yubikey-<span class="hljs-number">0</span>;

ssh-keygen -t ed25519-sk -C <span class="hljs-string">"user@domain.tld"</span> -f ~<span class="hljs-regexp">/.ssh/gi</span>thub-yubikey-<span class="hljs-number">1</span>;

chmod --change =<span class="hljs-number">400</span> ~<span class="hljs-regexp">/.ssh/gi</span>thub*; <span class="hljs-comment">#Owner only!</span>
</code></pre>
<ul>
<li><p><a href="https://forums.lawrencesystems.com/t/ssh-with-yubikey-fido-u2f-authentication/13024">lawrencesystems:</a> SSH with YubiKey FIDO U2F Authentication. \</p>
</li>
<li><p><a href="https://resources.yubico.com/53ZDUYE6/as/q3uxbe-6n9olc-9ywi4w/YubiKey_5_Series_Product_Brief.pdf">yubico:</a> YubiKey 5 Series \</p>
</li>
<li><p><a href="https://docs.github.com/en/authentication/connecting-to-github-with-ssh/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent">github:</a> Generating a new SSH key and adding it to the ssh-agent. \</p>
</li>
</ul>
<p>EOF</p>