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.
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QUICK START:
Unix:
./configure && make && make install
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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.
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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.
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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
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BUILD COMMANDS FROM TARBALL:
./configure
make
make install
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BUILD COMMANDS FROM SOURCE REPOSITORY CHECKOUT:
autoreconf -i -v -f
./configure
make
make install
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BUILD A TARBALL FROM SOURCE REPOSITORY CHECKOUT:
autoreconf -i -v -f
./configure
make distcheck
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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
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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
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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
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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.
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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.