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.