# Running OpenVPN Server on Windows

## Prerequisites

- A XCA PKI database https://youtu.be/ezzj3x207lQ

## Create Required Certificates

1. Launch XCA
2. Open the PKI database if it is not already (File > Open DataBase), enter password
3. Click on the Certificates tab, right click on your Intermediate CA certificate
4. Select New
5. On the Source tab, make sure Use this Certificate for signing is selected
6. Verify your Intermediate CA certificate is selected from the drop down
7. Click the Subject tab
8. Complete the Distinguished Name section

   internalName: OpenVPN Server
   countryName: US
   stateOrProvinceName: Virginia
   localityName: Northern
   organizationName: i12bretro
   organizationUnitName: i12bretro Certificate Authority
   commonName: vpn.i12bretro.local

9. Click the Generate a New Key button
10. Enter a name and set the key size to at least 2048
11. Click Create
12. Click on the Extensions tab
13. Set the Type dropdown to End Endity
14. Check the box next to Subject Key Identifier
15. Update the validity dates to fit your needs
16. Click the Key Usage tab
17. Under Key Usage select Digital Signature and Key Encipherment
18. Under Extended Key Usage select TLS Web Server Authentication
19. Click the Netscape tab
20. Deselect all options and clear the Netscape Comment field
21. Click OK to create the certificate
22. Click on the Certificates tab, right click on your Intermediate CA certificate again
23. Select New
24. On the Source tab, make sure Use this Certificate for signing is selected
25. Verify your Intermediate CA certificate is selected from the drop down
26. Click the Subject tab
27. Complete the Distinguished Name section

    internalName: OpenVPN Client #1
    countryName: US
    stateOrProvinceName: Virginia
    localityName: Northern
    organizationName: i12bretro
    organizationUnitName: i12bretro Certificate Authority
    commonName: VPN Client 1

28. Click the Generate a New Key button
29. Enter a name and set the key size to at least 2048
30. Click Create
31. Click on the Extensions tab
32. Set the Type dropdown to End Endity
33. Check the box next to Subject Key Identifier
34. Update the validity dates to fit your needs
35. Click the Key Usage tab
36. Under Key Usage select Digital Signature, Key Agreement
37. Under Extended Key Usage select TLS Web Client Authentication
38. Click the Netscape tab
39. Deselect all options and clear the Netscape Comment field
40. Click OK to create the certificate
41. On the Certificates tab, click the OpenVPN Server certificate
42. Select Extra > Generate DH Parameter
43. Type 2048 for DH parameter bits
44. Click OK
45. Select a location for dh.pem and click Save

## Exporting Required Files for OpenVPN

1. In XCA, click on the Certificates tab
2. Right click the Intermediate CA certificate > Export > File
3. Set the file name to ca.crt and verify the export format is PEM chain (*.pem)
4. Click OK
5. Right click the OpenVPN Server certificate > Export > File
6. Set the file name to server.crt and verify the export format is PEM (*.crt)
7. Click OK
8. Right click the OpenVPN Client #1 certificate > Export > File
9. Set the file name to OpenVPN_Client #1.crt and verify the export format is PEM (*.crt)
10. Click OK
11. Click on the Private Keys tab
12. Right click the OpenVPN Server key > Export > File
13. Set the file name to server.key and verify the export format is PKCS #8 (*.pk8)
14. Click OK
15. Right click the OpenVPN Client #1 key> Export > File
16. Set the file name to OpenVPN_Client #1.pk8 and verify the export format is PKCS #8 (*.pk8)
17. Click OK

## Installing and Configuring OpenVPN Server

1. Download the OpenVPN software Download
2. Run the downloaded .msi installer
3. Click Customize and make sure the OpenVPN Service option is selected for installation
4. Click Install Now
5. Once the installation completes, copy the exported ca.crt, server.crt, server.key and dh.pem files exported above to C:\Program Files\OpenVPN\config\Server
6. Open a text editor and paste the following text

   port 1194
   proto tcp
   dev tun

   ca "C:\\Program Files\\OpenVPN\\config\\Server\\ca.crt"
   cert "C:\\Program Files\\OpenVPN\\config\\Server\\server.crt"
   key "C:\\Program Files\\OpenVPN\\config\\Server\\server.key"
   dh "C:\\Program Files\\OpenVPN\\config\\Server\\dh.pem"

   topology subnet

   auth SHA256
   server 192.168.4.0 255.255.255.0
   keepalive 10 120
   cipher AES-256-GCM
   data-ciphers AES-256-GCM:AES-128-GCM:AES-256-CBC
   comp-lzo
   persist-key
   persist-tun
   verb 3

   client-to-client

   ifconfig-pool-persist "C:\\Program Files\\OpenVPN\\config\\Server\\ipp.txt"

   push "route 10.10.27.0 255.255.255.0"
   push "dhcp-option DNS 10.10.27.1"

7. Save the file as server.ovpn in the C:\Program Files\OpenVPN\config\Server directory
8. Open the Registry Editor by right clicking the Start button > Run > type regedit > Press Enter
9. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
10. Double click the IPEnableRouter key and change the value to 1
11. Close Registry Editor
12. Open Windows Services by right clicking the Start button > Run > type services.msc > Press Enter
13. Find the following services and set them to start automatically if they are not already

    Remote Access Connection Manager
    Routing and Remote Access

14. Open Network Connections by right clicking the Start button > Run > type ncpa.cpl > Press Enter
15. Right click on the main LAN connection > Properties
16. Click the Sharing tab
17. Check the box to Allow other network users to connect
18. From the dropdown select the OpenVPN TAP connection
19. Restart the Windows device for the changes to take effect
20. Once the system has rebooted, start the OpenVPN server by right clicking the OpenVPN icon in the system tray > System Profiles > Server > Connect

## Configuring Port Forwarding

At this point the OpenVPN server is running but you will need to configure your router to forward TCP port 1194 from the WAN to the IP address of the Windows host. The process to do this will vary based on your router, below are the steps required in DD-WRT

1. Open a web browser and navigate to the router IP address
2. Log in
3. Click the NAT / QoS tab in the top navigation menu
4. Click the Add button
5. Enter the following values

   Application: OpenVPN
   Protocol: TCP
   Source Net:
   Port from: 1194
   IP Address: (IP address of the Windows host)
   Port to: 1194
   Enable: (checked)

6. Click the Save button and then Apply Settings

## Creating the OpenVPN Client Profile and Testing

1. On the client device, download the OVPN template Download
2. Rename the .ovpn template something meaningful
3. Edit the .ovpn template replacing the following:

   <#replace with dynamic dns#> with a dynamic DNS or external IP address to your server
   <#replace with CA chain#> with the contents of ca.crt
   <#replace with client 1 cert #> with the contents of OpenVPN_Client #1.crt
   <#replace with client 1 key #> with the contents of OpenVPN_Client #1.pk8

4. Save your changes
5. Copy the .ovpn template to OpenVPN install directory/config
6. Right click OpenVPN GUI in the system tray > Connect

## Starting the OpenVPN Server on System Startup

1. Click on the Start Button > Type task > Launch Task Scheduler
2. Right click the Task Scheduler Library folder in the left pane > Create Basic Task...
3. Set the name to OpenVPN Server and optionally set a Description > Click Next
4. For the Trigger, select When the computer starts > Click Next
5. For the Action, select Start a program > Click Next
6. In the Program/script field, paste the following, editing the path if OpenVPN is not installed to the default location:

   "%ProgramFiles%\OpenVPN\bin\openvpn.exe"

7. In the Add arguments field, paste the following, editing the path to the .ps1 file if necessary:

   --config "C:\Program Files\OpenVPN\config\Server\server.ovpn"

8. Click Next
9. Click Finish
10. In the Properties dialog, click the Change User or Group... button
11. Type System in the Object name field > Click OK
12. Check the Run with highest privileges box
13. Click OK to create the scheduled task
14. To test, stop the OpenVPN Server using the system tray icon
15. Right click the OpenVPN Server task > Run
16. Check the OpenVPN system tray icon to verify the server is running

Further Reading: https://community.openvpn.net/openvpn/wiki/Easy_Windows_Guide#ServerConfigFile