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| computing:vpnserver [2018/05/17 15:47] – oemb1905 | computing:vpnserver [2023/02/11 13:04] – oemb1905 |
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| ------------------------------------------- | ------------------------------------------- |
| #**vpnserver** | * **vpnserver** |
| | * **Jonathan Haack** |
| | * **Haack's Networking** |
| | * **netcmnd@jonathanhaack.com** |
| ------------------------------------------- | ------------------------------------------- |
| |
| In this tutorial, you will create a vpn server on a WNDR3800 router running LEDE. Download the image as follows: | //vpnserver// |
| |
| https://downloads.openwrt.org/chaos_calmer/15.05.1/ar71xx/generic/openwrt-15.05.1-ar71xx-generic-wndr3800-squashfs-factory.img | ------------------------------------------- |
| http://downloads.lede-project.org/releases/17.01.4/targets/ar71xx/generic/lede-17.01.4-ar71xx-generic-wndr3800-squashfs-factory.img | |
| | This tutorial is for flashing a Netgear WNDR3800 router with openwrt and then building a vpn server on it with openvpn. The instructions here can easily be adapted to other hardware. First, download the stable release: |
| Add an address on the subnet of the router, and stop the network-manager from hijacking connection. Run ip a to obtain your interface name, as it may not be eth0. | |
| | [[http://downloads.openwrt.org|OpenWrt]] |
| | |
| | It is probably best to stop network manager; after that, assign a local ip address (on the same subnet as the router) to your network interface. |
| |
| sudo systemctl stop network-manager | sudo systemctl stop network-manager |
| ip a a 192.168.1.105/24 dev <eth0> | ip a a 192.168.1.105/24 dev <eth0> |
| |
| Put a paperclip in the reset button while device is off. Keeping it in, turn the device on, wait for flashing green. Be patient and do not turn power off or anything else during this process. First, ping the router. | Put a paperclip in the reset button while device is off. Keeping the paperclick depressed in the reset button gently, turn the device on, keeping the paperclip in and depressed until there is a flashing green light. At this point, I usually ping the router and/or run ethtool |
| | |
| ping 192.168.1.1 | ping 192.168.1.1 |
| | sudo ethtool <eth0> |
| |
| If you cannot successfully ping the router, then re-add your interface to the proper sub net and try again. If you can, then the curl command below should work. You know you succeeded if you get an error about "taking countermeasures" while pinging the device. Once that is done, execute the curl command as follows in order to flash the router with LEDE: | In the past, you would get a "taking countermeasures" response while pinging the device. At other times, ping just hangs (but it is connected). At any rate, after you are connected, flash the image with curl and tftp: |
| |
| curl -T ~/Downloads/openwrt-15.05.1-ar71xx-generic-wndr3800-squashfs-factory.img tftp://192.168.1.1 | curl -T ~/Downloads/openwrt-latest.img tftp://192.168.1.1 |
| |
| Now that we have openWRT on the router, we should enable https for the web admin panel before proceeding with anything else. First, verify that you completed the above steps correctly by visiting 192.168.1.1 in your web browser of choice. | After that, wait at least 5-10 minutes before attempting to log in to the device. In fact, before I log in, I prefer to shell into the router, update, install, and then upgrade all packages first. In order to do this, make sure to plug in an ethernet cable from your current LAN into the WAN port on the router so it can route. |
| |
| | ssh root@192.168.1.1 |
| opkg update | opkg update |
| opkg install luci-ssl | opkg install gzip openvpn-easy-rsa openvpn-openssl nano wget nmap tcpdump curl luci-ssl |
| nano /etc/config/uhttpd | opkg list-upgradable |
| | opkg upgrade <package> |
| In the config file, comment out the port 80 lines to prohibit using the router with https. Additionally, enter the parameters for the self-signed cert using the options at the bottom of the configuration file. Once you are done, restart the service and build the cert. | |
| | |
| | Before I get any further, I like to set up https. When you edit the config file, change the expiry dates to something large, enter your email/org, etc., and then start the service. |
| | |
| | nano /etc/config/uhttpd |
| /etc/init.d/uhttpd restart | /etc/init.d/uhttpd restart |
| |
| Now that we have https, we can begin to set up the vpn server on the WNDR. Using the template files in the directory openvpnconfig, download them to the router for ease, or use scp. (You can optionally configure everything without the template.) | Now, let's create custom config directories for openvpn and easy-rsa so they behave better when we are faced with upgrading packages on the router. |
| | |
| Method 1; copying the template directory from your host to the router. | |
| | |
| scp -r openvpnconfig root@192.168.1.1:/etc/config/ | |
| ssh root@192.168.1.1 | |
| | |
| Method 2; using wget to download the directory into your router. | mkdir /etc/config/openvpnconfig/ |
| | |
| ssh root@192.168.1.1 | |
| opkg update | |
| opkg install wget | |
| wget https://educationaction.biz/vpn/openvpnconfig.zip | |
| | |
| If you use this template and the key and config building script inside it, be aware of what it is doing for you; it is zipping the two keys and certificate authority together with the client config in one .zip file for easy downloading using scp. It also uses stock configuration options that can be adjusted as needed. Ok, let's set up the server now that we have our config template: | |
| | |
| opkg update | |
| opkg install zip openvpn-easy-rsa openvpn-openssl nano wget nmap tcpdump | |
| | |
| mv /etc/config/openvpnconfig/openvpn /etc/config/ | |
| mv /etc/easy-rsa /etc/config/openvpnconfig/ | mv /etc/easy-rsa /etc/config/openvpnconfig/ |
| cd /etc/ | cd /etc/ |
| ln -s config/openvpnconfig/easy-rsa ./ | ln -s config/openvpnconfig/easy-rsa ./ |
| | |
| | Now, let's enter the parameters on the vars file which determines how the openvpn server will be built, and also drives the default parameters for your client keys. I suggest editing the expiration date and the organization parameters (minimally). |
| | |
| nano /etc/config/openvpnconfig/easy-rsa/vars | nano /etc/config/openvpnconfig/easy-rsa/vars |
| nano /etc/config/openvpnconfig/openvpnWRT.conf | |
| nano /etc/config/openvpn | Now, let's rename the original config file, and then create two custom configuration files as follows: |
| build-ca | |
| build-dh [takes a long time, see alternate method below] | mv /etc/config/openvpn /etc/config/openvpn-original |
| build-key-server server | touch /etc/config/openvpn |
| | touch /etc/config/openvpnconfig/server.conf |
| | |
| | Examples of this .conf file can be found [[https://codetalkers.services|HERE]] Specify where the openvpn configuration is to be found; example provided below the text editor command. In the first configuration file, called openvpn, enter something like what is listed just below, but make sure you to change <server> to the name you will call your server when you build it below, remove the braces, and do not use special characters: |
| | |
| | ##/etc/config/openvpn## |
| | package openvpn |
| | config openvpn <server> |
| | option enabled 1 |
| | option config /etc/config/openvpnconfig/server.conf |
| | |
| | In the second configuration file, do something like this. Remember to change all the <addresses> in triangle braces below. Remember, the last address should be the address of the lan, not the vpn's address scheme. |
| | |
| | float |
| | port 1194 |
| | proto udp |
| | dev tun |
| | cipher AES-256-CBC |
| | tls-version-min 1.2 |
| | tls-cipher TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-256-CBC-SHA256:TLS-DHE-RSA-WITH-AES-128-GCM-SHA256 |
| | dh easy-rsa/pki/pki/dh.pem |
| | ca easy-rsa/pki/pki/ca.crt |
| | key easy-rsa/pki/pki/private/server.key |
| | cert easy-rsa/pki/pki/issued/server.crt |
| | ifconfig-pool-persist /tmp/ipp.txt |
| | client-config-dir clients |
| | status /var/log/openvpn-status.log |
| | mode server |
| | tls-server |
| | topology subnet |
| | push "topology subnet" |
| | ifconfig <10.66.66.1> 255.255.255.0 |
| | route-gateway <10.66.66.1> |
| | push "route-gateway <10.66.66.1>" |
| | ifconfig-pool <10.66.66.32> <10.66.66.254> 255.255.255.0 |
| | push "route <192.168.1.0> 255.255.255.0" |
| | |
| | Once those configuration files are built, you can now create the certificate authority, the diffie-hellman key, and certificate/private key for the server. |
| | |
| | cd /etc/config/openvpnconfig/easy-rsa/ |
| | easyrsa --batch init-pki |
| | easyrsa --batch gen-dh |
| | easyrsa --batch build-ca nopass |
| | easyrsa --batch build-server-full <server> nopass |
| |
| You can alternately choose to build the dh key on the **//__host__//** machine you are administering from and then scp it to the router when it completes as follows. Do not forget to symlink easy-rsa properly so this works. | Make sure that the name that you enter for <server> matches the name in the second configuration file below. Also, you can optionally create the diffie-hellman key on your home machine and scp it to the router to //save time// as follows, thereby omitting the gen-dh command above. If you can/want to do this, then on your home machine (not the router), do the following: |
| |
| sudo openssl dhparam -out /tmp/dh2048.pem 2048 | sudo openssl dhparam -out /tmp/dh2048.pem 2048 |
| scp /tmp/dh2048.pem root@xx.xx.xx.xx:/etc/config/openvpnconfig/easy-rsa/keys/ | scp /tmp/dh2048.pem root@192.168.1.1:/etc/easy-rsa/pki/pki/ |
| |
| You can now use the script contained in the template directory that you zipped earlier to create your client keys and config file; you are back on the **//__router__//** now. | After this, it is now time to create your keypair and ca. You do that as follows: |
| |
| /etc/config/openvpnconfig/easyrsa-user-setup-openwrt.sh [username] [server.com] | easyrsa --batch build-client-full <clientname> nopass |
| | |
| Or, if you did not use the template directory and the script, then change the vars file each time you need a key with the parameters that you desire, and then build the key, crt, and ca manually: | It is now time to scp the key, certificate, and authority from the router to your home device: |
| | |
| nano /etc/config/openvpnconfig/easy-rsa/vars | |
| pkitool [username] | |
| |
| If you chose not to use the template and script, then on each client you will need to create a config file with something like the following parameters; adjust these parameters as needed: | scp /etc/easy-rsa/pki/ca.crt /etc/easy-rsa/pki/private/clientname.key /etc/easy-rsa/pki/issued/clientname.crt root@10.10.10.100: |
| | |
| | Obviously, I am using an example home subnet here (10.10.10.0), so change that address to match your workstation. Once you have all three of those files, create a directory on the client workstation that intends to connect to the vpn server. After you create that directory and place these files in it, you need to create a connect-to-vpn.ovpn file that openvpn will use to connect to the vpn server. |
| | |
| | cd ~ |
| | mkdir vpn-connection |
| | cd vpn-connection |
| | mv ~/ca.crt ~/server.key ~/server.crt ~/vpn-connection/ |
| | sudo chmod 600 server.key |
| | touch connect-to-vpn.ovpn |
| | sudo chmod 640 server.crt ca.crt connect-to-vpn.ovpn |
| | nano connect-to-vpn.ovpn |
| | |
| nano /directory/to/keep/openvpn/keys/clientconfigname.ovpn | In the config file, enter something like this: |
| | |
| nobind | nobind |
| float | float |
| comp-lzo | |
| cipher AES-256-CBC | cipher AES-256-CBC |
| dev tun | dev tun |
| remote xx.xx.xx.xx 1194 udp | remote <external ip or DNS name here> 1194 udp |
| client | client |
| tls-exit | tls-exit |
| ca ca.crt | ca ca.crt |
| cert <client>.crt | cert <clientname>.crt |
| key <client>.key | key <clientname>.key |
| remote-cert-tls server | remote-cert-tls server |
| mute 5 | mute 5 |
| #redirect-gateway def1 | #redirect-gateway def1 |
| |
| You are now ready to set up the interfaces and firewall zones for the router using the web panel. Before you do this, you need to start the vpn service and ensure it is working. You should get two processes, one for the openvpn grep you just ran, and another for the service running: | Now that your client workstation is ready to test the connection, we need to return to setting up the server. First, if everything above was done correctly, then you should be able to start the vpn service as follows and verify that it is running: |
| |
| /etc/init.d/openvpn start | /etc/init.d/openvpn start |
| 31296 root 1356 S grep openvpn | 31296 root 1356 S grep openvpn |
| |
| If you did not get this output, then you should debug your configuration by running openvpn against your server configuration as follows, and use the output it provides to determine what you did wrong. | This is the output you want, showing that the service is running. If you do not get this, then run openvpn against the configuration files on the router and/or check the logs to determine your error. Here is a good place to start debugging: |
| |
| openvpn /etc/config/openvpnconfig/server.conf | openvpn /etc/config/openvpnconfig/server.conf |
| | |
| Now that the service is running and you have a client config, you can use the openWRT web page to create an interface and a firewall zone. Go to interfaces, add interface and name it VPN, select tun0 (unmanaged). Set up a fw zone at the same time or separately, and name it vpn_zone. Navigate to Network/Firewall, select the tab for traffic rules, and then add a rule that allows incoming vpn connections on udp 1194 //to device//, i.e., your router which is your vpn server. In the firewall zone, make sure to allow forwarding //to// the lan and wan, and //from// the lan. | |
| |
| {{ :computing:vpnint.png?600 |}} | Now that the service is running, let's log in to the router and adjust the settings a bit. In your web browser, visit 192.168.1.1, and log in/change password. After that, click /Interfaces/Add/tun0/ and enter "VPN" for the name (so its parsing matches the others). Once the interface is created, go to the firewall tab within it and create a matching firewall zone, call it lower-case vpn (this just distinguishes the zones from the interfaces). Go to the /Firewall tab, and then edit the vpn zone so that it has the WAN as a source destination. It is now time to test the vpn server //from your client workstation//: |
| {{ :computing:vpnint2.png?600 |}} | |
| {{ :computing:zone1.png?600 |}} | |
| {{ :computing:rule1.png?600 |}} | |
| {{ :computing:rule2.png?600 |}} | |
| |
| Now that you have a client configuration file set up, and the interfaces and firewall zones set up, you can install openvpn on your host; and be aware of how to execute the client - server handshake, thus initiating the openvpn connection. | cd ~/vpn-connection/ |
| | sudo openvpn connect-to-vpn.ovpn |
| | |
| | Since you did not suppress standard output, you should get the following the message, "Initialization Sequence Completed," to indicate a successful connection. Your vpn-server is now complete, and you can repeat the steps for building client keys stated above for other workstations/users. Also, if you need to automate the setup, you can use something like these scripts, which I tweaked a lot, from OpenWrt's wiki: |
| |
| sudo apt install openvpn | * [[https://repo.haacksnetworking.com/oemb1905/haackingclub/-/blob/master/vpnstuff/vpn-server-script.sh|vpn-server-scripts.sh]] |
| cd ~/directory/where/thekeys/youmade/above/are/ | * [[https://repo.haacksnetworking.com/oemb1905/haackingclub/-/blob/master/vpnstuff/vpn-client-script.sh|vp-client-scripts.sh]] |
| sudo openvpn clientconfigname.ovpn | |
| |
| To enable TLS and separately to enable a strong cipher, use these settings on the server configuration. The cipher setting matches the setting in the client configuration above. | -- -- -- -- -- |
| | |
| /etc/config/openvpnconfig/nameofvpnserver.conf | |
| tls-version-min 1.2 | |
| tls-cipher TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-256-CBC-SHA256:TLS-DHE-RSA-WITH-AES- 128-GCM-SHA256 | |
| cipher AES-256-CBC | |
| |
| Key permissions | Thanks to Jason Schaefer and Geoff Chesshire from [[http://schaeferconsulting.com|Schaefer IT Consulting]]. I am very grateful for their help with all of this. I also found the source documentation, [[https://openwrt.org/docs/guide-user/services/vpn/openvpn/basic|OpenWrt OpenVPN basic]], to be particularly helpful, especially when/if commands and config setups change in easy-rsa/openvpn. |
| |
| 640 for everything except the private key and 600 for that ... | --- //[[jonathan@haacksnetworking.com|oemb1905]] 2020/03/22 19:07// |
