Installation instructions for OpenVPN, a Secure Tunneling Daemon Copyright (C) 2002-2010 OpenVPN Technologies, 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 Windows MinGW, using MSYS bash shell: ./domake-win (see comments in the script for more info) Windows Visual Studio: python win\build_all.py ************************************************************************* To download OpenVPN, go to: http://openvpn.net/download.html For step-by-step installation instructions with real-world examples see: http://openvpn.net/howto.html For examples see: http://openvpn.net/examples.html ************************************************************************* SUPPORTED PLATFORMS: (1) Linux 2.2+ (2) Solaris (3) OpenBSD 3.0+ (Comes with OpenSSL and TUN devices by default) (4) Mac OS X Darwin (5) FreeBSD (6) NetBSD (7) Windows (WinXP and higher) 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. OPTIONAL (but recommended): (1) OpenSSL library, necessary for encryption, version 0.9.5 or higher required, available from http://www.openssl.org/ (2) 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. (3) Pthread library. 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/ ************************************************************************* CHECK OUT SOURCE FROM SOURCE REPOSITORY: git clone https://github.com/OpenVPN/openvpn Check out stable version: git checkout -b 2.2 remotes/origin/release/2.2 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 dist ************************************************************************* LOOPBACK 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) ************************************************************************* OPTIONS for ./configure: --disable-lzo disable LZO compression support [default=yes] --enable-lzo-stub don't compile LZO compression support but still allow limited interoperability with LZO-enabled peers [default=no] --disable-crypto disable crypto support [default=yes] --disable-ssl disable SSL support for TLS-based key exchange [default=yes] --enable-x509-alt-username enable the --x509-username-field feature [default=no] --disable-multi disable client/server support (--mode server + client mode) [default=yes] --disable-server disable server support only (but retain client support) [default=yes] --disable-plugins disable plug-in support [default=yes] --disable-eurephia disable support for the eurephia plug-in [default=yes] --disable-management disable management server support [default=yes] --enable-pkcs11 enable pkcs11 support [default=no] --disable-socks disable Socks support [default=yes] --disable-http-proxy disable HTTP proxy support [default=yes] --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=yes] --enable-password-save allow --askpass and --auth-user-pass passwords to be read from a file [default=yes] --enable-iproute2 enable support for iproute2 [default=no] --disable-def-auth disable deferred authentication [default=yes] --disable-pf disable internal packet filter [default=yes] --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-strict-options enable strict options check between peers (debugging option) [default=no] --enable-selinux enable SELinux support [default=no] --enable-systemd enable systemd suppport [default=no] ENVIRONMENT for ./configure: IFCONFIG full path to ipconfig utility ROUTE full path to route utility IPROUTE full path to ip utility NETSTAT path to netstat utility MAN2HTML path to man2html utility GIT path to git utility TAP_CFLAGS C compiler flags for tap OPENSSL_CRYPTO_CFLAGS C compiler flags for OPENSSL_CRYPTO, overriding pkg-config OPENSSL_CRYPTO_LIBS linker flags for OPENSSL_CRYPTO, overriding pkg-config OPENSSL_SSL_CFLAGS C compiler flags for OPENSSL_SSL, overriding pkg-config OPENSSL_SSL_LIBS linker flags for OPENSSL_SSL, overriding pkg-config POLARSSL_CFLAGS C compiler flags for polarssl POLARSSL_LIBS linker flags for polarssl LZO_CFLAGS C compiler flags for lzo LZO_LIBS linker flags for lzo PKCS11_HELPER_CFLAGS C compiler flags for PKCS11_HELPER, overriding pkg-config PKCS11_HELPER_LIBS linker flags for PKCS11_HELPER, overriding pkg-config ************************************************************************* BUILDING ON LINUX 2.4+ FROM RPM You can build a binary RPM directly from the OpenVPN tarball file: rpmbuild -tb [tarball] This command will build a binary RPM file and place it in the system RPM directory. You can then install the RPM with the standard RPM install command: rpm -ivh [binary-rpm] When you install the binary RPM, it will install sample-scripts/openvpn.init, which can be used to automatically start or stop one or more OpenVPN tunnels on system startup or shutdown, based on OpenVPN .conf files in /etc/openvpn. See the comments in openvpn.init for more information. Installing the RPM will also configure the TUN/TAP device node for linux 2.4. Note that the current openvpn.spec file, which instructs the rpm tool how to build a package, will build OpenVPN with all options enabled, including OpenSSL, LZO, and pthread linkage. Therefore all of these packages will need to be present prior to the RPM build, unless you edit the openvpn.spec file. ************************************************************************* TUN/TAP Driver Configuration: * Linux 2.4 or higher (with integrated TUN/TAP driver): (1) make device node: mknod /dev/net/tun c 10 200 (2a) add to /etc/modules.conf: alias char-major-10-200 tun (2b) load driver: modprobe tun (3) enable routing: echo 1 > /proc/sys/net/ipv4/ip_forward Note that either of steps (2a) or (2b) is sufficient. While (2a) only needs to be done once per install, (2b) 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. * Linux 2.2 or Solaris: You should obtain version 1.1 of the TUN/TAP driver from http://vtun.sourceforge.net/tun/ and follow the installation instructions. If you use OpenVPN on Linux 2.2 or 2.4 or Solaris, you may be suffering from a bug which causes connections to hang under heavy load. The symptoms are very similar to the MTU problems discussed frequently in the OpenVPN mailing lists. But it turns out that this bug is not caused by MTU problems. It's a bug in the tun/tap driver. A patch is provided here: http://openvpn.net/patch/tun-sb.patch * Solaris For 64 bit, I used the tun-1.1.tar.gz source and compiled it. Of course there is a but :) In the tun-1-1\solaris\Makefile I changed a line so it compiles with 64 bit CFLAGS = $(DEFS) -m64 -O2 -Wall -D_KERNEL -I. I just added -m64 and it worked. The tun driver works fine as said previously, however we noticed there is a minor problem when creating multiple tunnels on Solaris. Mr Tycho Fruru changed the code in tun.c file where he locked the tun device number to -1. This way it is impossible to specify the name of the tun device but it is still possible to have multiple devices. The modification will increment automatically meaning starting from tun0 ---> tunX I know you are not responsible for the tun coding but if you think the modification can be useful for you feel free to use it. http://openvpn.net/solaris/tun.c * FreeBSD 4.1.1+: 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 ships with tun0 and tun1 installed by default on pre-3.5 systems, while 3.5 and later have 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. * Mac OS X: 2005.02.13: Angelo Laub has developed a GUI for OS X: http://rechenknecht.net/OpenVPN-GUI/ 2004.10.26: Mattias Nissler has developed a new TUN/TAP driver for MAC OS X: http://www-user.rhrk.uni-kl.de/~nissler/tuntap/ Christoph Pfisterer's old TUN driver can be obtained at http://chrisp.de/en/projects/tunnel.html -- note that it is no longer being maintained. * Solaris9 Sparc/64 The kernel module for solaris can be generated by adding the -m64 switch to a modern gcc compiler (I'm using 3.2) The resulting kernel driver needs to be manually copied to /kernel/drv/sparcv9/ and then a reconfiguration reboot. (boot -r). * Windows XP/2003/Vista See domake-win for building instructions. See INSTALL-win32.txt for usage info. See the man page for more information, usage examples, and information on firewall configuration. ************************************************************************* 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.