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            <h1>Setting Up DD-WRT OpenVPN Server and Certificate Creation</h1>
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          <div id="content">
          <p>This is part five of a series of creating your own self-signed PKI and some ways to utilize the PKI to setup SSL for your web server or create your own OpenVPN server.</p>

<p>Disclaimer: I am not a security expert. This is just demonstrating an easy way to get OpenVPN up and running to allow access to a remote network from anywhere in the world.</p>

<p>For increased security, use a non-standard TCP or UDP port for your OpenVPN server, making sure to update the client &quot;remote&quot; line with the matching port number.</p>

<p>In this tutorial I am running DD-WRT in a VirtualBox VM. Learn how at https://www.youtube.com/watch?v=BRLukj4dZxk</p>

<h2>Create Required Certificates</h2>

<ol>
	<li>Launch XCA</li>
	<li>Open the PKI database if it is not already (File &gt; Open DataBase), enter password</li>
	<li>Click on the Certificates tab, right click on your Intermediate CA certificate</li>
	<li>Select New</li>
	<li>On the Source tab, make sure Use this Certificate for signing is selected</li>
	<li>Verify your Intermediate CA certificate is selected from the drop down</li>
	<li>Click the Subject tab</li>
	<li>Complete the Distinguished Name section
	<p>internalName: OpenVPN Server<br />
	countryName: US<br />
	stateOrProvinceName: Virginia<br />
	localityName: Northern<br />
	organizationName: i12bretro<br />
	organizationUnitName: i12bretro Certificate Authority<br />
	commonName: vpn.i12bretro.local</p>
	</li>
	<li>Click the Generate a New Key button</li>
	<li>Enter a name and set the key size to at least 2048</li>
	<li>Click Create</li>
	<li>Click on the Extensions tab</li>
	<li>Set the Type dropdown to End Endity</li>
	<li>Check the box next to Subject Key Identifier</li>
	<li>Update the validity dates to fit your needs</li>
	<li>Click the Key Usage tab</li>
	<li>Under Key Usage select Digital Signature and Key Encipherment</li>
	<li>Under Extended Key Usage select TLS Web Server Authentication</li>
	<li>Click the Netscape tab</li>
	<li>Deselect all options and clear the Netscape Comment field</li>
	<li>Click OK to create the certificate</li>
	<li>Click on the Certificates tab, right click on your Intermediate CA certificate again</li>
	<li>Select New</li>
	<li>On the Source tab, make sure Use this Certificate for signing is selected</li>
	<li>Verify your Intermediate CA certificate is selected from the drop down</li>
	<li>Click the Subject tab</li>
	<li>Complete the Distinguished Name section
	<p>internalName: OpenVPN Client #1<br />
	countryName: US<br />
	stateOrProvinceName: Virginia<br />
	localityName: Northern<br />
	organizationName: i12bretro<br />
	organizationUnitName: i12bretro Certificate Authority<br />
	commonName: VPN Client 1</p>
	</li>
	<li>Click the Generate a New Key button</li>
	<li>Enter a name and set the key size to at least 2048</li>
	<li>Click Create</li>
	<li>Click on the Extensions tab</li>
	<li>Set the Type dropdown to End Endity</li>
	<li>Check the box next to Subject Key Identifier</li>
	<li>Update the validity dates to fit your needs</li>
	<li>Click the Key Usage tab</li>
	<li>Under Key Usage select Digital Signature, Key Agreement</li>
	<li>Under Extended Key Usage select TLS Web Client Authentication</li>
	<li>Click the Netscape tab</li>
	<li>Deselect all options and clear the Netscape Comment field</li>
	<li>Click OK to create the certificate</li>
	<li>On the Certificates tab, click the OpenVPN Server certificate</li>
	<li>Select Extra &gt; Generate DH Parameter</li>
	<li>Type 2048 for DH parameter bits</li>
	<li>Click OK</li>
	<li>Select a location for dh2048.pem and click Save</li>
</ol>

<h2>Exporting Required Files for OpenVPN</h2>

<ol>
	<li>In XCA, click on the Certificates tab</li>
	<li>Right click the Intermediate CA certificate &gt; Export &gt; File</li>
	<li>Set the file name with a .pem extension and verify the export format is PEM chain (*.pem)</li>
	<li>Click OK</li>
	<li>Right click the OpenVPN Server certificate &gt; Export &gt; File</li>
	<li>Set the file name with a .crt extension and verify the export format is PEM (*.crt)</li>
	<li>Click OK</li>
	<li>Right click the OpenVPN Client #1 certificate &gt; Export &gt; File</li>
	<li>Set the file name with a .crt extension and verify the export format is PEM (*.crt)</li>
	<li>Click OK</li>
	<li>Click on the Private Keys tab</li>
	<li>Right click the OpenVPN Server key &gt; Export &gt; File</li>
	<li>Set the file name with a .pk8 extension and verify the export format is PKCS #8 (*.pk8)</li>
	<li>Click OK</li>
	<li>Right click the OpenVPN Client #1 key&gt; Export &gt; File</li>
	<li>Set the file name with a .pk8 extension and verify the export format is PKCS #8 (*.pk8)</li>
	<li>Click OK</li>
</ol>

<h2>Setting Up OpenVPN Server in DD-WRT</h2>

<ol>
	<li>Open a web browser and navigate to your DD-WRT IP address</li>
	<li>Login when prompted</li>
	<li>Select the Administration tab</li>
	<li>Select the Backup sub tab</li>
	<li>Click Backup at the very bottom</li>
	<li>Save the nvrambak file somewhere safe</li>
	<li>Select the Services tab</li>
	<li>Select the VPN sub tab</li>
	<li>Scroll down and select enable next to OpenVPN under the OpenVPN Server/Daemon header</li>
	<li>Set the OpenVPN Settings as the following:
	<ol start="1" style="list-style-type: lower-alpha;">
		<li>Start Type: System</li>
		<li>Config as: Server</li>
		<li>Server mode: Router (TUN)</li>
		<li>Network: 10.10.28.0</li>
		<li>Netmask: 255.255.255.0</li>
		<li>Port: 1194</li>
		<li>Tunnel Protocol: TCP</li>
		<li>Encyption Cipher: AES-256 GCM</li>
		<li>Hash Algorithm: SHA256</li>
		<li>Advanced Options: Enable</li>
		<li>TLS Cipher: TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384</li>
		<li>Compression: Compress lz4-v2</li>
		<li>Redirect default Gateway: Disable</li>
		<li>Allow Client to Client: Enable</li>
		<li>Allow duplicate CN: Disable</li>
		<li>Tunnel MT setting: 1500</li>
		<li>Tunnel UDP MSS-Fix: Disable</li>
	</ol>
	</li>
	<li>Paste the contents of OpenVPN_Server.crt into the Public Server Cert field</li>
	<li>Paste the contents of CA_Chain.pem into the CA Cert field</li>
	<li>Paste the contents of OpenVPN_Server.pem into the Private Server Key field</li>
	<li>Paste the contents of dh2048.pem into the DH PEM field</li>
	<li>Paste the following into the Additional Config field:
	<p>push &quot;route-gateway 10.10.27.27&quot;<br />
	push &quot;route 10.10.27.0 255.255.255.0&quot;<br />
	push &quot;dhcp-option DNS 10.10.27.1&quot;<br />
	push &quot;dhcp-option DNS 208.67.222.222&quot;</p>
	</li>
	<li>Note in the above:<br />
	route-gateway is the IP address of the internet gateway on your local network<br />
	route is the subnet of your local network<br />
	dhcp-option DNS sets DNS servers, in my case my domain controller and an OpenDNS server</li>
	<li>Click Save at the bottom</li>
	<li>Click Apply Settings</li>
	<li>Click the Administration tab</li>
	<li>Click the Command sub tab</li>
	<li>Paste the following into the Commands field
	<p>iptables -t nat -I PREROUTING -p udp --dport 1194 -j ACCEPT<br />
	iptables -I INPUT -p udp --dport 1194 -j ACCEPT<br />
	iptables -t nat -I PREROUTING -p tcp --dport 1194 -j ACCEPT<br />
	iptables -I INPUT -p tcp --dport 1194 -j ACCEPT<br />
	iptables -I INPUT -i tun2 -j ACCEPT<br />
	iptables -I FORWARD -i tun2 -j ACCEPT<br />
	iptables -I FORWARD -o tun2 -j ACCEPT<br />
	iptables -t nat -A POSTROUTING -s 10.10.28.0/24 -o eth0 -j MASQUERADE</p>
	</li>
	<li>Click Save Firewall at the bottom</li>
	<li>Click the Management sub tab</li>
	<li>Click Reboot Router at the very bottom</li>
</ol>

<h2>Installing OpenVPN Client Software and Testing</h2>

<ol>
	<li>Download the OpenVPN software <a href="https://openvpn.net/community-downloads/" target="_blank">Download</a></li>
	<li>Run the installer with all the default values</li>
	<li>Click the Start button and search OpenVPN GUI</li>
	<li>Select OpenVPN GUI from the results to start the application</li>
</ol>

<h2>Creating the OpenVPN Client Profile</h2>

<ol>
	<li>Download the OVPN template <a href="https://drive.google.com/open?id=1cwgQfCoQmDOMbY1kW7JK4q07ijHdl37y" target="_blank">Download</a></li>
	<li>Rename the .ovpn template something meaningful</li>
	<li>Edit the .ovpn template replacing the following:
	<p>&lt;#replace with dynamic dns#&gt; with a dynamic DNS or external IP address to your server<br />
	&lt;#replace with CA chain#&gt; with the contents of CA_Chain.pem<br />
	&lt;#replace with client 1 cert #&gt; with the contents of OpenVPN_Client #1.crt<br />
	&lt;#replace with client 1 key #&gt; with the contents of OpenVPN_Client #1.pk8</p>
	</li>
	<li>Save your changes</li>
	<li>Copy the .ovpn template to OpenVPN install directory/config</li>
	<li>Right click OpenVPN GUI in the system tray &gt; Connect</li>
</ol>
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