Installation instructions for OpenVPN, a Secure Tunneling Daemon
 

 Copyright (C) 2002-2019 OpenVPN Inc. This program is free software;

 you can redistribute it and/or modify
 it under the terms of the GNU General Public License version 2
 as published by the Free Software Foundation.
 
 *************************************************************************
 

 QUICK START:
 
   Unix:

     ./configure && make && make install

 
 *************************************************************************
 

 To download OpenVPN source code of releases, go to:

     https://openvpn.net/community-downloads/

 OpenVPN releases are also available as Debian/RPM packages:

     https://community.openvpn.net/openvpn/wiki/OpenvpnSoftwareRepos
 

 OpenVPN development versions can be found here:

    https://github.com/OpenVPN/openvpn
    https://gitlab.com/OpenVPN/openvpn
    https://sourceforge.net/p/openvpn/openvpn/ci/master/tree/

 They should all be in sync at any time.

 To download easy-rsa go to:
 
     https://github.com/OpenVPN/easy-rsa

 To download tap-windows (NDIS 6) driver source code go to:
 
     https://github.com/OpenVPN/tap-windows6
 

 To get the cross-compilation environment go to:
 
     https://github.com/OpenVPN/openvpn-build
 
 For step-by-step instructions with real-world examples see:
 

     https://community.openvpn.net/openvpn/wiki/GettingStartedwithOVPN

     https://community.openvpn.net/openvpn/wiki

     https://openvpn.net/community-resources/

 Also see the man page for more information.

 
 *************************************************************************
 
 SUPPORTED PLATFORMS:

   (1) Linux (kernel 2.6+)

   (2) Solaris

   (3) OpenBSD 5.1+
   (4) Mac OS X Darwin 10.5+
   (5) FreeBSD 7.4+
   (6) NetBSD 5.0+

   (7) Windows Vista or later for OpenVPN 2.4
   (8) Windows XP or later for OpenVPN 2.3

 
 SUPPORTED PROCESSOR ARCHITECTURES:
    In general, OpenVPN is word size and endian independent, so
    most processors should be supported.  Architectures known to
    work include Intel x86, Alpha, Sparc, Amd64, and ARM.
 
 REQUIRES:
   (1) TUN and/or TAP driver to allow user-space programs to control
       a virtual point-to-point IP or Ethernet device.  See
       TUN/TAP Driver Configuration section below for more info.

   (2) OpenSSL library, necessary for encryption, version 1.0.2 or higher

       required, available from http://www.openssl.org/

       or
   (3) mbed TLS library, an alternative for encryption, version 2.0 or higher

       required, available from https://tls.mbed.org/

 
 OPTIONAL:

   (3) LZO real-time compression library, required for link compression,

       available from http://www.oberhumer.com/opensource/lzo/
       OpenBSD users can use ports or packages to install lzo, but remember

       to add CFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib"
       directives to "configure", since gcc will not find them otherwise.

 
 OPTIONAL (for developers only):

   (1) Autoconf 2.59 or higher + Automake 1.9 or higher

       -- available from http://www.gnu.org/software/software.html
   (2) Dmalloc library
       -- available from http://dmalloc.com/

   (3) If using t_client.sh test framework, fping/fping6 is needed
       -- Available from http://www.fping.org/
       Note: t_client.sh needs an external configured OpenVPN server.
       See t_client.rc-sample for more info.

 
 *************************************************************************
 

 CHECK OUT SOURCE FROM SOURCE REPOSITORY:
 

   Clone the repository:
 
     git clone https://github.com/OpenVPN/openvpn

     git clone https://gitlab.com/OpenVPN/openvpn

     git clone git://openvpn.git.sourceforge.net/gitroot/openvpn/openvpn

 
   Check out stable version:
 

     git checkout release/2.4

 
   Check out master (unstable) branch:

     git checkout master

 
 
 *************************************************************************
 

 BUILD COMMANDS FROM TARBALL:
 
 	./configure
 	make
 	make install
 
 *************************************************************************
 

 BUILD COMMANDS FROM SOURCE REPOSITORY CHECKOUT:

 	autoreconf -i -v -f

 	./configure
 	make
 	make install
 
 *************************************************************************
 

 BUILD A TARBALL FROM SOURCE REPOSITORY CHECKOUT:

 	autoreconf -i -v -f

 	./configure

 	make distcheck

 
 *************************************************************************
 

 TESTS (after BUILD):

 
 make check (Run all tests below)
 
 Test Crypto:
 

 ./openvpn --genkey secret key

 ./openvpn --test-crypto --secret key
 
 Test SSL/TLS negotiations (runs for 2 minutes):
 

 ./openvpn --config sample/sample-config-files/loopback-client (In one window)
 ./openvpn --config sample/sample-config-files/loopback-server (Simultaneously in another window)

 For more thorough client-server tests you can configure your own, private test
 environment. See tests/t_client.rc-sample for details.
 

 To do the C unit tests, you need to have the "cmocka" test framework
 installed on your system.  More recent distributions already ship this
 as part of their packages/ports.  If your system does not have it,
 you can install cmocka with these commands:
 
   $ git clone https://git.cryptomilk.org/projects/cmocka.git
   $ cd cmocka
   $ mkdir build
   $ cd build
   $ cmake -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Debug ..
   $ make
   $ sudo make install
 
 

 *************************************************************************
 
 OPTIONS for ./configure:
 

   --disable-lzo           disable LZO compression support [default=yes]

   --disable-lz4           Disable LZ4 compression support
   --enable-comp-stub      Don't compile compression support but still allow limited interoperability with compression-enabled peers

   --disable-crypto        disable crypto support [default=yes]

   --disable-ofb-cfb       disable support for OFB and CFB cipher modes

                           [default=yes]
   --enable-x509-alt-username
                           enable the --x509-username-field feature
                           [default=no]
   --disable-server        disable server support only (but retain client
                           support) [default=yes]
   --disable-plugins       disable plug-in support [default=yes]
   --disable-management    disable management server support [default=yes]
   --enable-pkcs11         enable pkcs11 support [default=no]
   --disable-fragment      disable internal fragmentation support (--fragment)
                           [default=yes]
   --disable-multihome     disable multi-homed UDP server support (--multihome)
                           [default=yes]
   --disable-port-share    disable TCP server port-share support (--port-share)
                           [default=yes]
   --disable-debug         disable debugging support (disable gremlin and verb
                           7+ messages) [default=yes]
   --enable-small          enable smaller executable size (disable OCC, usage

                           message, and verb 4 parm list) [default=no]

   --enable-iproute2       enable support for iproute2 [default=no]
   --disable-def-auth      disable deferred authentication [default=yes]
   --disable-pf            disable internal packet filter [default=yes]

   --disable-plugin-auth-pam
                           disable auth-pam plugin [default=platform specific]
   --disable-plugin-down-root
                           disable down-root plugin [default=platform specific]
   --enable-pam-dlopen     dlopen libpam [default=no]

   --enable-strict         enable strict compiler warnings (debugging option)
                           [default=no]
   --enable-pedantic       enable pedantic compiler warnings, will not generate
                           a working executable (debugging option) [default=no]

   --enable-werror         promote compiler warnings to errors, will cause
                           builds to fail if the compiler issues warnings
                           (debugging option) [default=no]

   --enable-strict-options enable strict options check between peers (debugging
                           option) [default=no]
   --enable-selinux        enable SELinux support [default=no]

   --enable-systemd        enable systemd support [default=no]

   --enable-async-push     enable async-push support for plugins providing
                           deferred authentication [default=no]

 
 ENVIRONMENT for ./configure:
 

   PLUGINDIR   Path of plug-in directory [default=LIBDIR/openvpn/plugins]

   IFCONFIG    full path to ipconfig utility
   ROUTE       full path to route utility
   IPROUTE     full path to ip utility
   NETSTAT     path to netstat utility
   GIT         path to git utility

   SYSTEMD_ASK_PASSWORD
               path to systemd-ask-password utility
   SYSTEMD_UNIT_DIR
               Path of systemd unit directory [default=LIBDIR/systemd/system]
   TMPFILES_DIR
               Path of tmpfiles directory [default=LIBDIR/tmpfiles.d]

   RST2MAN     Path to rst2man utility
   RST2HTML    Path to rst2html utility

 
 ENVIRONMENT variables adjusting parameters related to dependencies
 

   TAP_CFLAGS  C compiler flags for tap

   LIBPAM_CFLAGS
               C compiler flags for libpam
   LIBPAM_LIBS linker flags for libpam

   PKCS11_HELPER_CFLAGS
               C compiler flags for PKCS11_HELPER, overriding pkg-config
   PKCS11_HELPER_LIBS
               linker flags for PKCS11_HELPER, overriding pkg-config

   OPENSSL_CFLAGS
               C compiler flags for OpenSSL
   OPENSSL_LIBS
               linker flags for OpenSSL
   MBEDTLS_CFLAGS
               C compiler flags for mbedtls
   MBEDTLS_LIBS
               linker flags for mbedtls
   LZO_CFLAGS  C compiler flags for lzo
   LZO_LIBS    linker flags for lzo
   LZ4_CFLAGS  C compiler flags for lz4
   LZ4_LIBS    linker flags for lz4
   libsystemd_CFLAGS
               C compiler flags for libsystemd, overriding pkg-config
   libsystemd_LIBS
               linker flags for libsystemd, overriding pkg-config
   P11KIT_CFLAGS
               C compiler flags for P11KIT, overriding pkg-config
   P11KIT_LIBS linker flags for P11KIT, overriding pkg-config

 
 *************************************************************************
 

 Linux distribution packaging:

 Each Linux distribution has their own way of doing packaging and their
 own set of guidelines of how proper packaging should be done.  It
 is therefore recommended to reach out to the Linux distributions you
 want to have OpenVPN packaged for directly.  The OpenVPN project wants
 to focus more on the OpenVPN development and less on the packaging
 and how packaging is done in all various distributions.

 For more details:

 * Arch Linux
   https://www.archlinux.org/packages/?name=openvpn

 * Debian
   https://packages.debian.org/search?keywords=openvpn&searchon=names
   https://tracker.debian.org/pkg/openvpn

 * Fedora / Fedora EPEL (Red Hat Enterprise Linux/CentOS/Scientific Linux)
   https://apps.fedoraproject.org/packages/openvpn/overview/
   https://src.fedoraproject.org/rpms/openvpn

 * Gentoo
   https://packages.gentoo.org/packages/net-vpn/openvpn
   https://gitweb.gentoo.org/repo/gentoo.git/tree/net-vpn/openvpn

 * openSUSE
   https://build.opensuse.org/package/show/network:vpn/openvpn
 
 * Ubuntu
   https://packages.ubuntu.com/search?keywords=openvpn
 
 In addition, the OpenVPN community provides a best-effort APT repository
 for Debian and Ubuntu:
 https://community.openvpn.net/openvpn/wiki/OpenvpnSoftwareRepos

 
 *************************************************************************
 
 TUN/TAP Driver Configuration:
 

 * Linux 2.6 or higher (with integrated TUN/TAP driver):

   (1) load driver:              modprobe tun
   (2) enable routing:           echo 1 > /proc/sys/net/ipv4/ip_forward

   Note that (1) needs to be done once per reboot.  If you install from RPM (see
   above) and use the openvpn.init script, these steps are taken care of for you.

 * FreeBSD:

 
   FreeBSD ships with the TUN/TAP driver, and the device nodes for tap0,
   tap1, tap2, tap3, tun0, tun1, tun2 and tun3 are made by default.
   However, only the TUN driver is linked into the GENERIC kernel.
 
   To load the TAP driver, enter: 
 
 	kldload if_tap
 
   See man rc(8) to find out how you can do this at boot time.
 
   The easiest way is to install OpenVPN from the FreeBSD ports system,
   the port includes a sample script to automatically load the TAP driver
   at boot-up time.
 
 * OpenBSD:
 

   OpenBSD has dynamically created tun* devices so you only need

   to create an empty /etc/hostname.tun0 (tun1, tun2 and so on) for each tun
   you plan to use to create the device(s) at boot.
 

 * Solaris:

   You need a TUN/TAP kernel driver for OpenVPN to work:

     http://www.whiteboard.ne.jp/~admin2/tuntap/

 * Windows

   OpenVPN on Windows needs a TUN/TAP kernel driver to work. OpenVPN installers
   include this driver, so installing it separately is not usually required.

   Windows XP/2003 must use the NDIS 5 (tap-windows) driver, whereas on more
   recent Windows versions it is recommended to use the NDIS 6 driver
   (tap-windows6) instead.

 
 *************************************************************************
 
 CAVEATS & BUGS:
 
 * I have noticed cases where TCP sessions tunneled over the Linux
   TAP driver (kernel 2.4.21 and 2.4.22) stall when lower --mssfix
   values are used.  The TCP sessions appear to unstall and resume
   normally when the remote VPN endpoint is pinged.
 
 * If run through a firewall using OpenBSDs packet filter PF and the
   filter rules include a "scrub" directive, you may get problems talking
   to Linux hosts over the tunnel, since the scrubbing will kill packets
   sent from Linux hosts if they are fragmented. This is usually seen as
   tunnels where small packets and pings get through but large packets
   and "regular traffic" don't. To circumvent this, add "no-df" to
   the scrub directive so that the packet filter will let fragments with
   the "dont fragment"-flag set through anyway.
 
 * Mixing OFB or CFB cipher modes with static key mode is not recommended,
   and is flagged as an error on OpenVPN versions 1.2.1 and greater.
   If you use the --cipher option to explicitly select an OFB or CFB
   cipher AND you are using static key mode, it is possible that there
   could be an IV collision if the OpenVPN daemons on both sides
   of the connection are started at exactly the same time, since
   OpenVPN uses a timestamp combined with a sequence number as the cipher
   IV for OFB and CFB modes.  This is not an issue if you are
   using CBC cipher mode (the default), or if you are using OFB or CFB
   cipher mode with SSL/TLS authentication.