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howtos:network_services:openvpn [2013/12/28 19:31 (UTC)] – chrisabela | howtos:network_services:openvpn [2022/04/18 12:55 (UTC)] – Updated for Slackware-15.0 chrisabela | ||
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====== OpenVPN - How to Set Up a Slackware Server and a Slackware Client ====== | ====== OpenVPN - How to Set Up a Slackware Server and a Slackware Client ====== | ||
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OpenVPN is an open source software application that implements virtual private network (VPN) techniques for creating secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It uses a custom security protocol that utilizes SSL/TLS for key exchange. It is capable of traversing network address translators (NATs) and firewalls. It was written by James Yonan and is published under the GNU General Public License (GPL). | OpenVPN is an open source software application that implements virtual private network (VPN) techniques for creating secure point-to-point or site-to-site connections in routed or bridged configurations and remote access facilities. It uses a custom security protocol that utilizes SSL/TLS for key exchange. It is capable of traversing network address translators (NATs) and firewalls. It was written by James Yonan and is published under the GNU General Public License (GPL). | ||
- | OpenVPN allows peers to authenticate each other using a pre-shared secret key, certificates, | + | OpenVPN allows peers to authenticate each other using a pre-shared secret key, certificates, |
===== 2. Scope and Objective ===== | ===== 2. Scope and Objective ===== | ||
Line 15: | Line 16: | ||
The emphasis is to provide a reliable method that can be easily followed to set-up OpenVPN on Slackware Servers and Clients. Nevertheless the process is still not free from pitfalls and require some attention and determination. | The emphasis is to provide a reliable method that can be easily followed to set-up OpenVPN on Slackware Servers and Clients. Nevertheless the process is still not free from pitfalls and require some attention and determination. | ||
- | This article comprises of a selection of other similar tutorials found on Internet particularly (2) and (3) and the documents contained in the downloaded source files. However these are reformatted to satisfy the objective. | + | This article comprises of a selection of other similar tutorials found on the Internet particularly (2) and (3) and the documents contained in the downloaded source files. However these are reformatted to satisfy the objective. |
===== 3. Installation ===== | ===== 3. Installation ===== | ||
- | Openvpn | + | OpenVPN |
- | If you want to confirm that Openvpn | + | If you want to confirm that OpenVPN |
< | < | ||
- | # ls /var/log/ | + | # ls /var/lib/ |
</ | </ | ||
===== 4. Requirements ===== | ===== 4. Requirements ===== | ||
- | Server and a Client computers would be needed. They would have to be connected to the Internet on two different Routers and different Network Routes. | + | Server and a Client computers would be needed. They would have to be connected to the Internet on two different Routers and different Network Routes. |
==== 4.1. Server DNS ==== | ==== 4.1. Server DNS ==== | ||
- | A URL is normally used to address the Server. This is not mandatory and instead you may use only the Internet IP. However it is recommended to use a URL to access the Server from the Internet, especially if it is connected to a dynamic IP, which is typical for domestic Internet connections. The author is using noip2(4) as it is free upon subscription. Noip2 is available from http:// | + | A URL is normally used to address the Server. This is not mandatory and instead you may use only the Internet IP. However it is recommended to use a URL to access the Server from the Internet, especially if it is connected to a dynamic IP, which is typical for domestic Internet connections. The author is using duckdns.org |
==== 4.2. Server details ==== | ==== 4.2. Server details ==== | ||
Line 40: | Line 41: | ||
hostname: server1 | hostname: server1 | ||
IP: 192.168.200.195/ | IP: 192.168.200.195/ | ||
- | URL: servervpn.no-ip.org | + | URL: servervpn.duckdns.org |
Network Interface: eth0 | Network Interface: eth0 | ||
</ | </ | ||
Line 52: | Line 53: | ||
</ | </ | ||
- | ==== 4.3 Administrator Rights ==== | + | ==== 4.4 Administrator Rights ==== |
- | You will need to have administrator rights to set up the Openvpn. This applies to both the Server and the Client. For simplicity, in this tutorial, it will be assumed that all actions will be performed by the root user. Naturally advanced users might be more discerning. | + | You will need to have administrator rights to set up OpenVPN. This applies to both the Server and the Client. For simplicity, in this tutorial, it will be assumed that all actions will be performed by the root user. Naturally, advanced users might be more discerning. |
- | ==== 4.4 Possible Constraints and Possible Solutions for a WiFi equipped Client ==== | + | ==== 4.5 Possible Constraints and Possible Solutions for a WiFi equipped Client ==== |
The availability of two Routers might be challenging. Consider that interactive sessions on both the Server and Client will be needed before the VPN is set up. If the Client is equipped with a WiFi interface there might be some easy solutions that may be considered: | The availability of two Routers might be challenging. Consider that interactive sessions on both the Server and Client will be needed before the VPN is set up. If the Client is equipped with a WiFi interface there might be some easy solutions that may be considered: | ||
- | - Use a 3G smart phone' | + | - Use the data smart phone' |
- | - Connect the Client to another WiFi available in the vicinity of the Server. Some lucky people live in areas were benevolent neighbours provide them with openly accessible Internet WiFi. It is recommended to request permission before taking up this solution. In case that no such open service exists, you may find it appropriate to request a temporary password from a friendly neighbour for the private encrypted WiFi service. | + | - Nowadays, many public |
- | - Nowadays, many governmental | + | |
===== 5. Creating a Public Key Infrastructure (PKI) using the easy-rsa Scripts ===== | ===== 5. Creating a Public Key Infrastructure (PKI) using the easy-rsa Scripts ===== | ||
- | The PKI may be created on any computer | + | The PKI may be created on any computer, but it is probably more sensible to be done on both the Server and the Client as both would need it. An easy way to build the PKI is to use the '' |
< | < | ||
# cd | # cd | ||
- | # git clone git:// | + | # git clone http:// |
</ | </ | ||
Line 76: | Line 76: | ||
< | < | ||
- | # tar cvf easy-rsa.tar easy-rsa | + | # tar czvf easy-rsa.tgz easy-rsa |
</ | </ | ||
Line 102: | Line 102: | ||
</ | </ | ||
- | You will be prompted for another | + | You will be prompted for the PEM pass phrase, to reverify it and to confirm that the name of the entity is indeed server1. Now you may proceed to sign this request: |
< | < | ||
Line 108: | Line 108: | ||
</ | </ | ||
- | Confirm the request by entering | + | Confirm the request by entering |
Now create two additional key files: | Now create two additional key files: | ||
Line 116: | Line 116: | ||
# openssl dhparam -out dh2048.pem 2048 | # openssl dhparam -out dh2048.pem 2048 | ||
# cd / | # cd / | ||
- | # / | + | # / |
</ | </ | ||
Line 123: | Line 123: | ||
Follow these steps on the Client to create the needed keys and certificates: | Follow these steps on the Client to create the needed keys and certificates: | ||
- | You will need the easy-rsa scripts, so you can copy easy-rsa tarball from the Server to the Client and extract it: | + | You will need the '' |
< | < | ||
# cd | # cd | ||
- | # tar xvf easy-rsa.tar | + | # tar xvf easy-rsa.tgz |
</ | </ | ||
Line 138: | Line 138: | ||
</ | </ | ||
- | You will be prompted for another | + | You will be prompted for a PEM pass phrase, to re-verify it and to confirm that the name of the entity is indeed client1. In this article I am using the hostnames for clarity (in this case: client1), but you may choose any name. |
- | Copy pki/ | + | Copy '' |
=== 5.2.1 Sign the Client' | === 5.2.1 Sign the Client' | ||
- | For the purpose of this article, it is assumed that the Client' | + | For the purpose of this article, it is assumed that the Client' |
< | < | ||
Line 152: | Line 152: | ||
</ | </ | ||
- | When prompted enter “yes” and the server1 CA PEM pass phrase. | + | When prompted enter "yes" |
- | Copy the generated $HOME/ | + | Copy the generated |
back to the client. | back to the client. | ||
===== 6. Setting up the Server ===== | ===== 6. Setting up the Server ===== | ||
- | Copy the following files generated by the easy-rsa scripts to their respective directories in the / | + | Copy the following files generated by the easy-rsa scripts to their respective directories in the '' |
< | < | ||
Line 170: | Line 170: | ||
</ | </ | ||
- | Copy the sample | + | Copy the provided '' |
< | < | ||
- | # cd /tmp/ | + | # cp /etc/openvpn/ |
- | # wget -c \ | + | |
- | > ftp:// | + | |
- | # cd /usr/src/ | + | |
- | # tar xvf / | + | |
</ | </ | ||
- | Copy the file server.conf contained in the source to the openvpn configuration directory: | + | Edit the following lines of '' |
- | + | ||
- | < | + | |
- | # cp openvpn-2.3.2/ | + | |
- | > / | + | |
- | </ | + | |
- | + | ||
- | Edit the following lines of / | + | |
From these lines: | From these lines: | ||
Line 195: | Line 184: | ||
cert server.crt | cert server.crt | ||
key server.key | key server.key | ||
- | |||
dh dh1024.pem | dh dh1024.pem | ||
- | ;tls-auth ta.key 0 # This file is secret | ||
- | ;user nobody | + | ;topology subnet |
- | ;group nobody | + | |
+ | tls-auth ta.key 0 # This file is secret | ||
+ | |||
+ | cipher AES-256-CBC | ||
; | ; | ||
+ | |||
</ | </ | ||
Line 214: | Line 205: | ||
dh / | dh / | ||
+ | |||
+ | topology subnet | ||
tls-auth / | tls-auth / | ||
- | user nobody | + | data-ciphers-fallback AES-256-CBC |
- | group nobody | + | |
log-append | log-append | ||
</ | </ | ||
- | Finally add the following to / | + | < |
- | < | + | Create |
- | # If you want to use OpenVPN as a daemon, uncomment this line. | + | |
- | # Generally speaking, servers should run OpenVPN as a daemon | + | |
- | daemon | + | |
- | </code> | + | |
- | + | ||
- | My full server.conf is the following: | + | |
< | < | ||
- | ################################################# | + | # chmod 600 /root/password.ovpn |
- | # Sample OpenVPN 2.0 config file for # | + | |
- | # multi-client server. | + | |
- | # # | + | |
- | # This file is for the server side # | + | |
- | # of a many-clients <-> one-server | + | |
- | # OpenVPN configuration. | + | |
- | # # | + | |
- | # OpenVPN also supports | + | |
- | # single-machine <-> single-machine | + | |
- | # configurations (See the Examples page # | + | |
- | # on the web site for more info). | + | |
- | # # | + | |
- | # This config should work on Windows | + | |
- | # or Linux/BSD systems. | + | |
- | # Windows to quote pathnames and use # | + | |
- | # double backslashes, | + | |
- | # " | + | |
- | # # | + | |
- | # Comments are preceded with '#' | + | |
- | ################################################# | + | |
- | + | ||
- | # Which local IP address should OpenVPN | + | |
- | # listen on? (optional) | + | |
- | ;local a.b.c.d | + | |
- | + | ||
- | # Which TCP/UDP port should OpenVPN listen on? | + | |
- | # If you want to run multiple OpenVPN instances | + | |
- | # on the same machine, use a different port | + | |
- | # number for each one. You will need to | + | |
- | # open up this port on your firewall. | + | |
- | port 1194 | + | |
- | + | ||
- | # TCP or UDP server? | + | |
- | ;proto tcp | + | |
- | proto udp | + | |
- | + | ||
- | # "dev tun" will create a routed IP tunnel, | + | |
- | # "dev tap" will create an ethernet tunnel. | + | |
- | # Use "dev tap0" if you are ethernet bridging | + | |
- | # and have precreated a tap0 virtual interface | + | |
- | # and bridged it with your ethernet interface. | + | |
- | # If you want to control access policies | + | |
- | # over the VPN, you must create firewall | + | |
- | # rules for the the TUN/TAP interface. | + | |
- | # On non-Windows systems, you can give | + | |
- | # an explicit unit number, such as tun0. | + | |
- | # On Windows, use " | + | |
- | # On most systems, the VPN will not function | + | |
- | # unless you partially or fully disable | + | |
- | # the firewall for the TUN/TAP interface. | + | |
- | ;dev tap | + | |
- | dev tun | + | |
- | + | ||
- | # Windows needs the TAP-Win32 adapter name | + | |
- | # from the Network Connections panel if you | + | |
- | # have more than one. On XP SP2 or higher, | + | |
- | # you may need to selectively disable the | + | |
- | # Windows firewall for the TAP adapter. | + | |
- | # Non-Windows systems usually don't need this. | + | |
- | ;dev-node MyTap | + | |
- | + | ||
- | # SSL/ | + | |
- | # (cert), and private key (key). | + | |
- | # and the server must have their own cert and | + | |
- | # key file. The server and all clients will | + | |
- | # use the same ca file. | + | |
- | # | + | |
- | # See the " | + | |
- | # of scripts for generating RSA certificates | + | |
- | # and private keys. Remember to use | + | |
- | # a unique Common Name for the server | + | |
- | # and each of the client certificates. | + | |
- | # | + | |
- | # Any X509 key management system can be used. | + | |
- | # OpenVPN can also use a PKCS #12 formatted key file | + | |
- | # (see " | + | |
- | ca /etc/ | + | |
- | cert / | + | |
- | key / | + | |
- | + | ||
- | # Diffie hellman parameters. | + | |
- | # Generate your own with: | + | |
- | # | + | |
- | # Substitute 2048 for 1024 if you are using | + | |
- | # 2048 bit keys. | + | |
- | dh / | + | |
- | + | ||
- | # Configure server mode and supply a VPN subnet | + | |
- | # for OpenVPN to draw client addresses from. | + | |
- | # The server will take 10.8.0.1 for itself, | + | |
- | # the rest will be made available to clients. | + | |
- | # Each client will be able to reach the server | + | |
- | # on 10.8.0.1. Comment this line out if you are | + | |
- | # ethernet bridging. See the man page for more info. | + | |
- | server 10.8.0.0 255.255.255.0 | + | |
- | + | ||
- | # Maintain a record of client <-> virtual IP address | + | |
- | # associations in this file. If OpenVPN goes down or | + | |
- | # is restarted, reconnecting clients can be assigned | + | |
- | # the same virtual IP address from the pool that was | + | |
- | # previously assigned. | + | |
- | ifconfig-pool-persist ipp.txt | + | |
- | + | ||
- | # Configure server mode for ethernet bridging. | + | |
- | # You must first use your OS's bridging capability | + | |
- | # to bridge the TAP interface with the ethernet | + | |
- | # NIC interface. | + | |
- | # IP/netmask on the bridge interface, here we | + | |
- | # assume 10.8.0.4/ | + | |
- | # must set aside an IP range in this subnet | + | |
- | # (start=10.8.0.50 end=10.8.0.100) to allocate | + | |
- | # to connecting clients. | + | |
- | # out unless you are ethernet bridging. | + | |
- | ; | + | |
- | + | ||
- | # Configure server mode for ethernet bridging | + | |
- | # using a DHCP-proxy, where clients talk | + | |
- | # to the OpenVPN server-side DHCP server | + | |
- | # to receive their IP address allocation | + | |
- | # and DNS server addresses. | + | |
- | # your OS's bridging capability to bridge the TAP | + | |
- | # interface with the ethernet NIC interface. | + | |
- | # Note: this mode only works on clients (such as | + | |
- | # Windows), where the client-side TAP adapter is | + | |
- | # bound to a DHCP client. | + | |
- | ; | + | |
- | + | ||
- | # Push routes to the client to allow it | + | |
- | # to reach other private subnets behind | + | |
- | # the server. | + | |
- | # private subnets will also need | + | |
- | # to know to route the OpenVPN client | + | |
- | # address pool (10.8.0.0/ | + | |
- | # back to the OpenVPN server. | + | |
- | ;push "route 192.168.10.0 255.255.255.0" | + | |
- | ;push "route 192.168.20.0 255.255.255.0" | + | |
- | + | ||
- | # To assign specific IP addresses to specific | + | |
- | # clients or if a connecting client has a private | + | |
- | # subnet behind it that should also have VPN access, | + | |
- | # use the subdirectory " | + | |
- | # configuration files (see man page for more info). | + | |
- | + | ||
- | # EXAMPLE: Suppose the client | + | |
- | # having the certificate common name " | + | |
- | # also has a small subnet behind his connecting | + | |
- | # machine, such as 192.168.40.128/ | + | |
- | # First, uncomment out these lines: | + | |
- | ; | + | |
- | ;route 192.168.40.128 255.255.255.248 | + | |
- | # Then create a file ccd/ | + | |
- | # | + | |
- | # This will allow Thelonious' | + | |
- | # access the VPN. This example will only work | + | |
- | # if you are routing, not bridging, i.e. you are | + | |
- | # using "dev tun" and " | + | |
- | + | ||
- | # EXAMPLE: Suppose you want to give | + | |
- | # Thelonious a fixed VPN IP address of 10.9.0.1. | + | |
- | # First uncomment out these lines: | + | |
- | ; | + | |
- | ;route 10.9.0.0 255.255.255.252 | + | |
- | # Then add this line to ccd/ | + | |
- | # | + | |
- | + | ||
- | # Suppose that you want to enable different | + | |
- | # firewall access policies for different groups | + | |
- | # of clients. | + | |
- | # (1) Run multiple OpenVPN daemons, one for each | + | |
- | # | + | |
- | # for each group/ | + | |
- | # (2) (Advanced) Create a script to dynamically | + | |
- | # | + | |
- | # from different clients. | + | |
- | # page for more info on learn-address script. | + | |
- | ; | + | |
- | + | ||
- | # If enabled, this directive will configure | + | |
- | # all clients to redirect their default | + | |
- | # network gateway through the VPN, causing | + | |
- | # all IP traffic such as web browsing and | + | |
- | # and DNS lookups to go through the VPN | + | |
- | # (The OpenVPN server machine may need to NAT | + | |
- | # or bridge the TUN/TAP interface to the internet | + | |
- | # in order for this to work properly). | + | |
- | ;push " | + | |
- | + | ||
- | # Certain Windows-specific network settings | + | |
- | # can be pushed to clients, such as DNS | + | |
- | # or WINS server addresses. | + | |
- | # http:// | + | |
- | # The addresses below refer to the public | + | |
- | # DNS servers provided by opendns.com. | + | |
- | ;push " | + | |
- | ;push " | + | |
- | + | ||
- | # Uncomment this directive to allow different | + | |
- | # clients to be able to " | + | |
- | # By default, clients will only see the server. | + | |
- | # To force clients to only see the server, you | + | |
- | # will also need to appropriately firewall the | + | |
- | # server' | + | |
- | ; | + | |
- | + | ||
- | # Uncomment this directive if multiple clients | + | |
- | # might connect with the same certificate/ | + | |
- | # files or common names. | + | |
- | # only for testing purposes. | + | |
- | # each client should have its own certificate/ | + | |
- | # pair. | + | |
- | # | + | |
- | # IF YOU HAVE NOT GENERATED INDIVIDUAL | + | |
- | # CERTIFICATE/ | + | |
- | # EACH HAVING ITS OWN UNIQUE " | + | |
- | # UNCOMMENT THIS LINE OUT. | + | |
- | ; | + | |
- | + | ||
- | # The keepalive directive causes ping-like | + | |
- | # messages to be sent back and forth over | + | |
- | # the link so that each side knows when | + | |
- | # the other side has gone down. | + | |
- | # Ping every 10 seconds, assume that remote | + | |
- | # peer is down if no ping received during | + | |
- | # a 120 second time period. | + | |
- | keepalive 10 120 | + | |
- | + | ||
- | # For extra security beyond that provided | + | |
- | # by SSL/TLS, create an "HMAC firewall" | + | |
- | # to help block DoS attacks and UDP port flooding. | + | |
- | # | + | |
- | # Generate with: | + | |
- | # | + | |
- | # | + | |
- | # The server and each client must have | + | |
- | # a copy of this key. | + | |
- | # The second parameter should be ' | + | |
- | # on the server and ' | + | |
- | tls-auth / | + | |
- | + | ||
- | # Select a cryptographic cipher. | + | |
- | # This config item must be copied to | + | |
- | # the client config file as well. | + | |
- | ;cipher BF-CBC | + | |
- | ;cipher AES-128-CBC | + | |
- | ;cipher DES-EDE3-CBC | + | |
- | + | ||
- | # Enable compression on the VPN link. | + | |
- | # If you enable it here, you must also | + | |
- | # enable it in the client config file. | + | |
- | comp-lzo | + | |
- | + | ||
- | # The maximum number of concurrently connected | + | |
- | # clients we want to allow. | + | |
- | ; | + | |
- | + | ||
- | # It's a good idea to reduce the OpenVPN | + | |
- | # daemon' | + | |
- | # | + | |
- | # You can uncomment this out on | + | |
- | # non-Windows systems. | + | |
- | user nobody | + | |
- | group nobody | + | |
- | + | ||
- | # The persist options will try to avoid | + | |
- | # accessing certain resources on restart | + | |
- | # that may no longer be accessible because | + | |
- | # of the privilege downgrade. | + | |
- | persist-key | + | |
- | persist-tun | + | |
- | + | ||
- | # Output a short status file showing | + | |
- | # current connections, | + | |
- | # and rewritten every minute. | + | |
- | status openvpn-status.log | + | |
- | + | ||
- | # By default, log messages will go to the syslog (or | + | |
- | # on Windows, if running as a service, they will go to | + | |
- | # the " | + | |
- | # Use log or log-append to override this default. | + | |
- | # " | + | |
- | # while " | + | |
- | # or the other (but not both). | + | |
- | ;log | + | |
- | log-append | + | |
- | + | ||
- | # Set the appropriate level of log | + | |
- | # file verbosity. | + | |
- | # | + | |
- | # 0 is silent, except for fatal errors | + | |
- | # 4 is reasonable for general usage | + | |
- | # 5 and 6 can help to debug connection problems | + | |
- | # 9 is extremely verbose | + | |
- | verb 3 | + | |
- | + | ||
- | # Silence repeating messages. | + | |
- | # sequential messages of the same message | + | |
- | # category will be output to the log. | + | |
- | ;mute 20 | + | |
- | + | ||
- | # If you want to use OpenVPN as a daemon, uncomment this line. | + | |
- | # Generally speaking, servers should run OpenVPN as a daemon | + | |
- | daemon | + | |
</ | </ | ||
- | < | + | On the Server, edit ''/ |
- | Copy the rc.openvpn listed hereunder and place under / | + | |
< | < | ||
- | #!/bin/sh | + | askpass |
- | # | + | auth-nocache |
- | # /etc/rc.d/ | + | |
- | # | + | |
- | # Start/ | + | |
- | # | + | |
- | + | ||
- | ovpn_start() { | + | |
- | if [ -x / | + | |
- | echo " | + | |
- | / | + | |
- | fi | + | |
- | } | + | |
- | + | ||
- | ovpn_stop() { | + | |
- | killall openvpn | + | |
- | } | + | |
- | + | ||
- | ovpn_restart() { | + | |
- | ovpn_stop | + | |
- | sleep 2 | + | |
- | ovpn_start | + | |
- | } | + | |
- | + | ||
- | case " | + | |
- | ' | + | |
- | ovpn_start | + | |
- | ;; | + | |
- | ' | + | |
- | ovpn_stop | + | |
- | ;; | + | |
- | ' | + | |
- | ovpn_restart | + | |
- | ;; | + | |
- | *) | + | |
- | echo " | + | |
- | esac | + | |
</ | </ | ||
- | Then give it executable | + | Create a directory to store the OpenVPN service PID and restrict its permissions: |
< | < | ||
- | # chmod 755 /etc/rc.d/rc.openvpn | + | mkdir /run/openvpn/ |
+ | chmod 700 /run/openvpn/ | ||
</ | </ | ||
- | Eventually when you start openvpn on the server, you may read / | + | Give the OpenVPN '' |
< | < | ||
- | # cat /var/log/openvpn.log | + | # chmod +x /etc/rc.d/rc.openvpn |
</ | </ | ||
===== 7. Port Forwarding ===== | ===== 7. Port Forwarding ===== | ||
- | YYou will need to forward traffic from the port you have chosen for Openvpn | + | You will need to forward traffic from the port you have chosen for OpenVPN |
- | In case if you have misplaced such documentation, | + | In case if you have misplaced such documentation, |
===== 8. Setting up the Client ===== | ===== 8. Setting up the Client ===== | ||
Line 604: | Line 253: | ||
On the Client machine perform the following instructions to set it up. | On the Client machine perform the following instructions to set it up. | ||
- | Download | + | Copy the provided '' |
< | < | ||
- | # cp /usr/src/openvpn-*/sample/ | + | # cp /etc/ |
- | > / | + | |
</ | </ | ||
Line 623: | Line 271: | ||
key client.key | key client.key | ||
- | ;tls-auth ta.key 1 | + | tls-auth ta.key 1 |
+ | |||
+ | cipher AES-256-CBC | ||
</ | </ | ||
Line 629: | Line 279: | ||
< | < | ||
- | remote servervpn.no-ip.org 1194 | + | remote servervpn.duckdns.org 1194 |
user nobody | user nobody | ||
Line 639: | Line 289: | ||
tls-auth / | tls-auth / | ||
+ | |||
+ | data-ciphers-fallback AES-256-CBC | ||
+ | |||
+ | auth-nocache | ||
+ | |||
+ | log-append | ||
</ | </ | ||
- | < | + | < |
- | You will need the this files that were generated by the Client' | + | You will need this file that was generated by the Client' |
< | < | ||
- | $HOME/ | + | cp $HOME/ |
+ | > / | ||
</ | </ | ||
- | and the following from the Server' | + | and the following from the Server' |
< | < | ||
- | ca.crt | + | $HOME/ |
- | ta.key | + | $HOME/ |
</ | </ | ||
- | You will also need client1.crt generated by the Server as explained above in Chapter 5.2.1. | + | and this file from the Server as well: |
- | Place these files as indicated in client.conf. So ca.crt and client1.crt go under / | + | < |
+ | / | ||
+ | </code> | ||
- | Also in client.conf, comment out the line: | + | Place these files as indicated |
+ | |||
+ | ===== 9. Testing the VPN ===== | ||
+ | |||
+ | On the Server: | ||
< | < | ||
- | ns-cert-type server | + | # / |
</ | </ | ||
- | and insert | + | Enter the Server PEM pass phrase when prompted. |
+ | |||
+ | On the Client: | ||
< | < | ||
- | remote-cert-tls server | + | # / |
</ | </ | ||
- | My full client.conf is the following: | + | Enter the Client PEM pass phrase when prompted. To stop OpenVPN on the Client just hit CTRL+C |
+ | |||
+ | On both you should see a new network interface called tun0. To verify, run this ip command: | ||
< | < | ||
- | ############################################## | + | # / |
- | # Sample client-side OpenVPN 2.0 config file # | + | </ |
- | # for connecting to multi-client server. | + | |
- | # # | + | |
- | # This configuration can be used by multiple # | + | |
- | # clients, however each client should have # | + | |
- | # its own cert and key files. | + | |
- | # # | + | |
- | # On Windows, you might want to rename this # | + | |
- | # file so it has a .ovpn extension | + | |
- | ############################################## | + | |
- | # Specify that we are a client and that we | + | Naturally you can ping the Server from Client (or vice versa): |
- | # will be pulling certain config file directives | + | |
- | # from the server. | + | |
- | client | + | |
- | # Use the same setting as you are using on | + | For example, from the Client: |
- | # the server. | + | |
- | # On most systems, the VPN will not function | + | |
- | # unless you partially or fully disable | + | |
- | # the firewall for the TUN/TAP interface. | + | |
- | ;dev tap | + | |
- | dev tun | + | |
- | # Windows needs the TAP-Win32 adapter name | + | < |
- | # from the Network Connections panel | + | # ping -c 3 10.8.0.1 |
- | # if you have more than one. On XP SP2, | + | PING 10.8.0.1 (10.8.0.1) 56(84) bytes of data. |
- | # you may need to disable the firewall | + | 64 bytes from 10.8.0.1: icmp_req=1 ttl=64 time=2888 ms |
- | # for the TAP adapter. | + | 64 bytes from 10.8.0.1: icmp_req=2 ttl=64 time=1997 ms |
- | ;dev-node MyTap | + | 64 bytes from 10.8.0.1: icmp_req=3 ttl=64 time=1324 ms |
- | # Are we connecting to a TCP or | + | --- 10.8.0.1 ping statistics --- |
- | # UDP server? | + | 3 packets transmitted, |
- | # on the server. | + | rtt min/ |
- | ;proto tcp | + | </ |
- | proto udp | + | |
- | # The hostname/IP and port of the server. | + | If you fail to set-up a VPN connection, you may want to look in ''/ |
- | # You can have multiple remote entries | + | |
- | # to load balance between the servers. | + | |
- | remote servervpn.no-ip.org 1194 | + | |
- | ;remote my-server-2 1194 | + | |
- | # Choose a random host from the remote | + | < |
- | # list for load-balancing. | + | tal -f / |
- | # try hosts in the order specified. | + | </ |
- | ; | + | |
- | # Keep trying indefinitely to resolve the | + | ===== 10. Logrotate (6) ===== |
- | # host name of the OpenVPN server. Very useful | + | |
- | # on machines which are not permanently connected | + | |
- | # to the internet such as laptops. | + | |
- | resolv-retry infinite | + | |
- | # Most clients don't need to bind to | + | This is logrotate configuration for OpenVPN. It prevents you from ending up with huge OpenVPN log files. |
- | # a specific local port number. | + | |
- | nobind | + | |
- | # Downgrade privileges after initialization (non-Windows only) | + | < |
- | user nobody | + | / |
- | group nobody | + | |
+ | rotate 12 | ||
+ | compress | ||
+ | copytruncate | ||
+ | delaycompress | ||
+ | missingok | ||
+ | notifempty | ||
+ | } | ||
+ | </ | ||
- | # Try to preserve some state across restarts. | + | ===== 11. Storing the PEM pass phrase in a secure file and automatic start of service after booting ===== |
- | persist-key | + | |
- | persist-tun | + | |
- | # If you are connecting through an | + | As hinted in Chapter 6, to start the OpenVPN |
- | # HTTP proxy to reach the actual | + | |
- | # server, put the proxy server/IP and | + | |
- | # port number here. | + | |
- | # if your proxy server requires | + | |
- | # authentication. | + | |
- | ; | + | |
- | ;http-proxy [proxy server] [proxy port #] | + | |
- | # Wireless networks often produce a lot | + | As ''/ |
- | # of duplicate packets. Set this flag | + | |
- | # to silence duplicate packet warnings. | + | |
- | ;mute-replay-warnings | + | |
- | # SSL/TLS parms. | + | On the Client, edit ''/ |
- | # See the server config file for more | + | |
- | # description. | + | |
- | # a separate .crt/.key file pair | + | |
- | # for each client. | + | |
- | # file can be used for all clients. | + | |
- | ca / | + | |
- | cert / | + | |
- | key / | + | |
- | # Verify server certificate by checking | + | < |
- | # that the certicate has the nsCertType | + | askpass |
- | # field set to " | + | auth-nocache |
- | # important precaution to protect against | + | </ |
- | # a potential attack discussed here: | + | |
- | # http://openvpn.net/ | + | |
- | # | + | |
- | # To use this feature, you will need to generate | + | |
- | # your server certificates with the nsCertType | + | |
- | # field set to " | + | |
- | # script in the easy-rsa folder will do this. | + | |
- | ; | + | |
- | remote-cert-tls server | + | |
- | # If a tls-auth key is used on the server | + | Create |
- | # then every client must also have the key. | + | |
- | tls-auth / | + | |
- | # Select a cryptographic cipher. | + | < |
- | # If the cipher option is used on the server | + | mkdir / |
- | # then you must also specify it here. | + | chmod 700 / |
- | ;cipher x | + | </ |
- | # Enable compression on the VPN link. | + | An alternate method (albeit less secure) is to remove |
- | # Don't enable this unless it is also | + | |
- | # enabled in the server config file. | + | |
- | comp-lzo | + | |
- | # Set log file verbosity. | + | < |
- | verb 3 | + | # cd / |
+ | # openssl rsa -in server1.key -out tmp.key | ||
+ | </ | ||
- | # Silence repeating messages | + | Enter the pass phrase. |
- | ;mute 20 | + | |
- | #</ | + | |
- | + | ||
- | ===== 9. Testing the VPN ===== | + | |
- | + | ||
- | On the Server: | + | |
< | < | ||
- | # /etc/rc.d/rc.openvpn start | + | # mv tmp.key server1.key |
+ | # chmod 600 server1.key | ||
</ | </ | ||
- | Enter the Server PEM pass phrase when prompted. | + | If you had them remove these lines from ''/ |
- | + | ||
- | On the Client: | + | |
< | < | ||
- | # /usr/sbin/ | + | askpass |
+ | auth-nocache | ||
</ | </ | ||
- | Enter the Client | + | Similarly, this can be repeated for the Client: |
- | + | ||
- | On both you should see a new network interface called tun0. On the Server, I obtained the following: | + | |
< | < | ||
- | # ifconfig tun0 | + | # cd / |
- | tun0: flags=4305< | + | # openssl rsa -in client1.key -out tmp.key |
- | inet 10.8.0.1 netmask 255.255.255.255 | + | |
- | unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00 | + | |
- | RX packets 0 bytes 0 (0.0 B) | + | |
- | RX errors 0 dropped 0 overruns 0 frame 0 | + | |
- | TX packets 0 bytes 0 (0.0 B) | + | |
- | TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 | + | |
</ | </ | ||
- | Similarly on the Client: | + | Enter the pass phrase. |
< | < | ||
- | # ifconfig tun0 | + | # mv tmp.key client1.key |
- | tun0: flags=4305< | + | # chmod 600 client1.key |
- | inet 10.8.0.6 netmask 255.255.255.255 | + | |
- | | + | |
- | RX packets 0 bytes 0 (0.0 B) | + | |
- | RX errors 0 dropped 0 overruns 0 frame 0 | + | |
- | TX packets 0 bytes 0 (0.0 B) | + | |
- | TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 | + | |
</ | </ | ||
- | Naturally | + | Then, if you had it, remove this line from ''/ |
- | + | ||
- | For example, from the Client: | + | |
< | < | ||
- | # ping -c 3 10.8.0.1 | + | askpass |
- | PING 10.8.0.1 (10.8.0.1) 56(84) bytes of data. | + | |
- | 64 bytes from 10.8.0.1: icmp_req=1 ttl=64 time=2888 ms | + | |
- | 64 bytes from 10.8.0.1: icmp_req=2 ttl=64 time=1997 ms | + | |
- | 64 bytes from 10.8.0.1: icmp_req=3 ttl=64 time=1324 ms | + | |
- | + | ||
- | --- 10.8.0.1 ping statistics --- | + | |
- | 3 packets transmitted, | + | |
- | rtt min/avg/ | + | |
</ | </ | ||
- | To start the openvpn service automatically | + | If you intend to use the '' |
< | < | ||
- | # Start the OpenVPN Server | + | mkdir / |
- | if [ -x /etc/rc.d/rc.openvpn-server ]; then | + | chmod 700 /run/openvpn/ |
- | / | + | chmod +x / |
- | fi | + | |
</ | </ | ||
- | ===== 10. IP Routing ===== | + | ===== 12. IP Routing ===== |
Up to now we have created a tunnel device on both the Server and the Client called tun0 which is visible only to these two machines. However more work is needed to route the Client' | Up to now we have created a tunnel device on both the Server and the Client called tun0 which is visible only to these two machines. However more work is needed to route the Client' | ||
- | ==== 10.1 Server Configuration | + | ==== 12.1 IP Forwarding |
- | Enable | + | On the Server, enable |
< | < | ||
Line 891: | Line 473: | ||
</ | </ | ||
- | Create a file with the same name of the client (in this case client1) and enter the following line in / | + | Create a file with the same name of the client (in this case '' |
< | < | ||
Line 899: | Line 481: | ||
Replace 192.168.1.0 255.255.255.0 by the Network Route of your Client. | Replace 192.168.1.0 255.255.255.0 by the Network Route of your Client. | ||
- | Similarly edit / | + | Similarly edit '' |
< | < | ||
push "route 192.168.200.0 255.255.255.0" | push "route 192.168.200.0 255.255.255.0" | ||
- | client-config-dir ccd | + | client-config-dir |
route 192.168.1.0 255.255.255.0 | route 192.168.1.0 255.255.255.0 | ||
Line 914: | Line 496: | ||
Naturally replace 192.168.200.0 255.255.255.0 with the Server' | Naturally replace 192.168.200.0 255.255.255.0 with the Server' | ||
+ | 208.67.222.222 and 208.67.220.220 are the OpenDNS IPv4 DNS service addresses. | ||
- | 208.67.222.222 and 208.67.220.220 are the OpenDNS IP addresses. | + | <note warning>Up to now the DNS push configuration has not been successful.</note> |
- | Next you will have to configure some iptables NAT forwarding on the Server (only). | + | You can either use the original Client DNS servers or else you may rewrite / |
< | < | ||
- | # iptables -F | + | # OpenDNS Servers |
+ | nameserver 208.67.222.222 | ||
+ | nameserver 208.67.220.220 | ||
</ | </ | ||
- | And then: | + | According to your routing table however, it is still worth trying to use the DNS servers listed by the Client, I find that they are generally still available, so you would not need to do anything. However do be aware of possible DNS leaks if you are concerned about your privacy. |
- | < | + | Some users have reported that their Client' |
- | # iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE | + | |
- | </code> | + | |
- | On Slackware, such a line may be included in / | + | Next you will have to configure NAT forwarding on the Server |
- | The exact lines which you need to include depend on whether you already entered your own iptables filter chains and rules, but I will assume that that this is not the case. | + | You can do this by means of iptables or the newer nftables (not both). |
+ | |||
+ | ==== 12.2 NAT forwarding with iptables ==== | ||
- | As already explained, as a minimum you only need to enter the following lines in / | + | Start by flushing |
< | < | ||
- | #!/bin/sh | + | # /usr/sbin/iptables -F |
- | iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE | + | |
</ | </ | ||
- | If on the other hand you would like a better firewall and you are at least moderately confident with iptables, I propose the following script to be included in your / | + | And then: |
< | < | ||
- | #!/ | + | # / |
- | # Start/ | + | </ |
- | + | ||
- | IPT=/ | + | |
- | + | ||
- | firewall_start() { | + | |
- | + | ||
- | # flush the iptables | + | |
- | echo -e " | + | |
- | $IPT -F | + | |
- | + | ||
- | # policies | + | |
- | $IPT -P OUTPUT DROP | + | |
- | $IPT -P INPUT DROP | + | |
- | $IPT -P FORWARD DROP | + | |
- | $IPT -N SERVICES # services is a custom chain | + | On Slackware, such a line may be included in ''/ |
- | # allowed output | + | The exact lines which you need to include depend on whether you already entered your own iptables filter chains and rules, but I will assume that that this is not the case. |
- | $IPT -A OUTPUT -o lo -j ACCEPT | + | |
- | $IPT -A OUTPUT -o eth0 -j ACCEPT | + | |
- | $IPT -A OUTPUT -o tun0 -j ACCEPT | + | |
- | # allowed inputs | + | As already explained, as a minimum you only need to enter the following lines in ''/ |
- | #$IPT -A INPUT -i lo -j ACCEPT # uncomment if the host is a desktop | + | |
- | $IPT -A INPUT -m conntrack --ctstate ESTABLISHED, | + | |
- | $IPT -A INPUT -j SERVICES # append the services chain to the input | + | |
- | | + | < |
- | $IPT -A FORWARD -i eth0 -o tun0 -m state --state ESTABLISHED, | + | #!/bin/sh |
- | $IPT -A FORWARD -s 10.8.0.0/24 -o eth0 -j ACCEPT | + | iptables |
- | + | ||
- | # masquerade the openvpn network | + | |
- | $IPT -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE | + | |
- | + | ||
- | # allow sshd on the default tcp port 22 | + | |
- | #$IPT -A SERVICES -p tcp --dport 22 -j ACCEPT # Uncomment to allow sshd | + | |
- | + | ||
- | # allow openvpn for the non-default tcp port 443 | + | |
- | $IPT -A SERVICES -p tcp --dport 443 -j ACCEPT | + | |
- | + | ||
- | echo " | + | |
- | } | + | |
- | + | ||
- | firewall_stop() { | + | |
- | echo -e " | + | |
- | + | ||
- | # polcies (permissive) | + | |
- | $IPT -P OUTPUT ACCEPT | + | |
- | $IPT -P INPUT ACCEPT | + | |
- | $IPT -P FORWARD ACCEPT | + | |
- | + | ||
- | # flush the iptables | + | |
- | $IPT -F | + | |
- | + | ||
- | # delete the services custom chain | + | |
- | $IPT -X SERVICES | + | |
- | echo " | + | |
- | } | + | |
- | + | ||
- | firewall_status() { | + | |
- | $IPT -vL | + | |
- | } | + | |
- | + | ||
- | case " | + | |
- | ' | + | |
- | firewall_start | + | |
- | ;; | + | |
- | ' | + | |
- | firewall_stop | + | |
- | ;; | + | |
- | ' | + | |
- | firewall_stop | + | |
- | firewall_start | + | |
- | ;; | + | |
- | ' | + | |
- | firewall_status | + | |
- | ;; | + | |
- | *) | + | |
- | echo "Usage $0 start|stop|restart|status" | + | |
- | esac | + | |
</ | </ | ||
- | Give the firewall rc script executable permission: | + | Give the firewall |
< | < | ||
Line 1038: | Line 553: | ||
</ | </ | ||
- | Restart the Openvpn | + | Restart the OpenVPN |
< | < | ||
Line 1050: | Line 565: | ||
</ | </ | ||
- | ===== 11. Firewalls ===== | + | ==== 12.3 NAT forwarding with nftables |
- | In the previous chapter we referred to a firewall | + | If you prefer '' |
- | In order to penetrate through the Client | + | < |
+ | / | ||
+ | / | ||
+ | / | ||
+ | / | ||
+ | </ | ||
+ | |||
+ | ===== 13. Firewalls ===== | ||
+ | |||
+ | You may find that on some networks, UDP port 1194 is blocked, and so the Client will be unable to connect. | ||
< | < | ||
Line 1068: | Line 592: | ||
</ | </ | ||
- | and / | + | Also, comment out '' |
+ | |||
+ | You also have to modify your Router' | ||
+ | |||
+ | Edit '' | ||
< | < | ||
Line 1084: | Line 612: | ||
</ | </ | ||
- | The Server' | + | ===== 14. Sources ===== |
- | + | ||
- | < | + | |
- | # allow vpn on the default udp port 1194 | + | |
- | $IPT -A SERVICES -p udp --dport 1194 -j ACCEPT | + | |
- | </ | + | |
- | + | ||
- | to: | + | |
- | + | ||
- | < | + | |
- | # allow vpn on the custom tcp port 443 | + | |
- | $IPT -A SERVICES -p tcp --dport 443 -j ACCEPT | + | |
- | </ | + | |
- | + | ||
- | You also have to modify your Router' | + | |
- | + | ||
- | ===== 12. Sources ===== | + | |
(1) http:// | (1) http:// | ||
Line 1108: | Line 620: | ||
(3) http:// | (3) http:// | ||
- | (4) http://www.no-ip.com | + | (4) http://www.duckdns.org |
+ | (5) http:// | ||
+ | |||
+ | (6) https:// | ||
+ | |||
+ | * Written for Slackware 15.0 in April 2022 | ||
* Originally written by [[wiki: | * Originally written by [[wiki: | ||
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{{tag> | {{tag> | ||
- |