[[TOC(inline, depth=1)]]

= Project structure =

Look [wiki:CodeRepositories here] for details.

= Building natively on *NIX =

Building natively on *NIX has not changed much, you can still use roughly the same process as before. If building from Git sources, first do a

{{{
$ autoreconf -vi
}}}

If building from a release tarball, you can skip the above step. To configure, build and install OpenVPN, use these commands:

{{{
$ ./configure <configure-options>
$ make
$ make install
}}}

In most cases, you'd use something like this:

{{{
$ ./configure
}}}

If you're using password authentication, you may be interested in support for password stored in (properly protected!) files:

{{{
$ ./configure --enable-password-save
}}}

Or, if you want to use smart cards and such, you should use

{{{
$ ./configure --enable-pkcs11
}}}

= Cross-compiling on *NIX ("generic" subdir) =

== Installing prequisites ==

You can use the ''generic'' buildsystem from ''openvpn-build'' subproject to cross-compile OpenVPN using any toolchain to any target environment. The build host must have a *NIX-like environment, e.g. Linux, *BSD or Cygwin (on Windows). First make sure you have installed the correct tools before you start:

 * [http://mingw-w64.sourceforge.net/ mingw-w64], version 2.0.x, [wiki:InstallingMingwW64 may need backported patches] (if building Windows binaries)
 * gcc-*-arm-linux-gnueabi (if building Arm binaries)
 * [http://git-scm.com/ Git]
 * [http://www.nongnu.org/man2html/ man2html] (for ''windows-nsis'' builds)
 * [http://waterlan.home.xs4all.nl/dos2unix.html dos2unix] (for ''windows-nsis'' builds)
 * [http://nsis.sourceforge.net/Main_Page NSIS]: if you need support for riducuously long PATHs, you need to [wiki::BuildingMakeNSIS build NSIS] yourself. 
 * [http://osslsigncode.sourceforge.net/ osslsigncode] ([wiki:BuildingUsingGenericBuildsystem#Installingosslsigncode installation instructions])

On Ubuntu 12.04 (64-bit) you the following commands should take care of everything except osslsigncode:

{{{
$ apt-get update
$ apt-get install git-core mingw-w64 gcc-4.6-arm-linux-gnueabi man2html dos2unix nsis unzip
}}}

If you're building using Cygwin on Windows, it's best to configure Git not to translate LF to CR/LF. For this reason it's probably best to use Cygwin's Git. Also take a look at Cygwin's README to see which packages are required.

== Checking out openvpn-build repository ==

Check out the ''openvpn-build'' subproject using Git:

{{{
$ git clone https://github.com/OpenVPN/openvpn-build.git
}}}

Then go to the ''generic'' directory:

{{{
$ cd openvpn-build/generic
}}}

== Customizing the build ==

To customize the build options, refer to ''build.vars'', it contains the defaults for building, most settings can be customized by setting environment variable before executing the build script.

If you want to use your own, local sources (e.g. for OpenSSL or OpenVPN), put them in ''sources'' directory, so that the ''generic'' buildsystem knows not to download them from a remote site. The cached tarballs will be used even if they're of a different version than what would be downloaded. This is useful for building custom version.

== Building OpenVPN and it's dependencies ==

The ''./build'' command fetches all the dependencies, builds them and builds OpenVPN. To build a native binary:

{{{
$ IMAGEROOT=`pwd`/image-native ./build
}}}

To build for Windows 32bit on Linux 64bit:

{{{
$ IMAGEROOT=`pwd`/image-win32 CHOST=i686-w64-mingw32 \
    CBUILD=x86_64-pc-linux-gnu ./build
}}}

To build for Windows 64bit on Linux 64bit:

{{{
$ IMAGEROOT=`pwd`/image-win64 CHOST=x86_64-w64-mingw32 \
    CBUILD=x86_64-pc-linux-gnu ./build
}}}

To build for Arm on Linux 64bit:

{{{
$ IMAGEROOT=`pwd`/image-arm CHOST=arm-linux-gnueabi \
    CBUILD=x86_64-pc-linux-gnu ./build
}}}

== Building dependencies only ==

To build only dependencies (helpful for developers):

{{{
$ DO_ONLY_DEPS=1 IMAGEROOT=`pwd`/deps-win32 CHOST=i686-w64-mingw32 \
    CBUILD=x86_64-pc-linux-gnu ./build
}}}

For typical OpenVPN installations you'll most likely want to use something like this:

{{{
$ DEP=location of the dependencies
$ ./configure host=... \
    CFLAGS="-I$DEP/include" LDFLAGS="-L$DEB/lib" \
    --enable-pkcs11 \
    PKCS11_HELPER_CFLAGS=" " PKCS11_HELPER_LIBS="-lpkcs11-helper"
}}}

== Cleaning up ==

If you want to start from scratch, do

{{{
$ cd openvpn-build/generic
$ rm -f sources/*
$ rm -rf image-*
}}}

= Creating a NSIS installer ("windows-nsis" subdir) =

== Building and packaging ==

You can use the scripts in ''openvpn-build/windows-nsis'' to create a [http://nsis.sourceforge.net NSIS] installer for Windows. The scripts use the generic build system to build OpenVPN and it's dependencies (e.g. lzo, openssl), and use [http://sourceforge.net/projects/osslsigncode osslsigncode] for signing the resulting binaries, if requested.

NSIS must be available on system. If installed not in path or standard location set MAKENSIS environment variable. Same goes for OSSLSIGNCODE.

First check out ''openvpn-build'' as described [wiki:BuildingUsingGenericBuildsystem#Checkingoutopenvpn-buildrepository here]. Check ''build-complete.vars'' for variables which you can set in the shell to point the ''build-complete'' script to the correct dependency packages (''easy-rsa'' and ''tap-windows''). If you're building a snapshot, ensure that OPENVPN_VERSION in ''version.m4'' (in Git) matches that in ''../generic/build.vars''; also make sure other variables in that file are correct.

Then, if you want to build an (unsigned) installer, do the following:

{{{
$ cd openvpn-build/windows-nsis
$ ./build-snapshot
}}}

'''NOTE:''' Ensure that ''OPENVPN_VERSION'' is set to what ''version.m4'' says.  

If you want to build a signed ''snapshot'' installer (with all included libraries and executables signed) use something like this instead:

{{{
$ ./build-snapshot --sign --sign-pkcs12=signingkey.p12 --sign-pkcs12-pass=yourpassphrase --sign-timestamp="http://timestamp.domain.com"
}}}

If you're doing a release build, use ''build-complete'' instead:

{{{
$ ./build-complete --sign --sign-pkcs12=signingkey.p12 --sign-pkcs12-pass=yourpassphrase --sign-timestamp="http://timestamp.domain.com"
}}}


Refer to ''./build-complete --help'' and ''build-snapshot'' for more options.

'''NOTE:''' To make sure fresh tarballs are used, empty ./sources directory before building.

== Packaging without building ==

Building OpenVPN and it's dependencies takes time, so if you're only making changes to ''openvpn.nsi'' you should only rebuild the Windows installers:

{{{
makensis -DARCH=x86_64\
-DVERSION_STRING=2.3_master-I001_master\
-DOPENVPN_ROOT=tmp\\installer\\openvpn\
-DTAP_WINDOWS_INSTALLER=tmp\\tap-windows-9.9.2.exe\
-DSPECIAL_BUILD\
-DUSE_TAP_WINDOWS\
-DEASYRSA_ROOT=tmp\\installer\\easy-rsa\
-DUSE_EASYRSA\
-DUSE_OPENVPN_GUI\
-DOUTPUT=./openvpn-test.exe\
-DPACKAGE_NAME=OpenVPN openvpn.nsi
}}}

Make sure the variables match your latest complete build.
= Building natively on Windows using the MSVC toolchain ("msvc" subdir) =

== Installing prequisites ==

MSVC build was written with least dependencies in mind. You'll need only [http://www.activestate.com/activeperl Perl] and Visual Studio 2010 (Express).

== Checking out openvpn-build repository ==

Launch a Git Bash and follow [wiki:BuildingUsingGenericBuildsystem#Checkingoutopenvpn-buildrepository these] instructions. Next go to the ''msvc'' directory and build:

{{{
> cd openvpn-build/msvc
> build
}}}


This fetches all the dependencies, builds them and builds OpenVPN.

== Building dependencies only ==

To build only dependencies (helpful for developers):

{{{
> set DO_ONLY_DEPS=true
> set TARGET=c:\Temp\build-deps
> build
}}}

== Customizing the build ==

To customize the build options, refer to ''build-env.bat'', it contains the defaults for building, most settings can be customized by setting environment variable before executing the build script.

You can also configure the build to use a Git repository or tarball of your liking, for example:

{{{
set OPENVPN_GIT=git://openvpn.git.sourceforge.net/gitroot/openvpn/openvpn.git
set OPENVPN_SOURCE=git
set OPENVPN_BRANCH=master
}}}

== Build OpenVPN manually ==

Provided you built the dependencies you can use the MSVC build system within OpenVPN tree, edit ''build-env-local.bat'' which is loaded by ''build.bat''. The variables defined in ''build-env-local.bat'' override the defaults given in ''build-env.bat''. For example, you can manually define the location of dependencies:

{{{
set OPENVPN_DEPROOT=c:\Temp\build-deps
}}}

Then open IDE using:

{{{
> msvc-dev
}}}

Or build using:

{{{
> msvc-build
}}}

= Building TAP-Windows =

Required software: Recent Windows DDK, [http://nsis.sourceforge.net NSIS].

First clone the ''tap-windows'' repository, e.g. using ''Git Bash'':

{{{
$ git clone https://github.com/OpenVPN/tap-windows
}}}

Next you need to set some environment variables. For self-signed test certificates use something like this:

{{{
set CODESIGN_PKCS12=c:\Users\John\tap-windows\my-self-signed-certificate.p12
set CODESIGN_PASS=mypassphrase
set CODESIGN_ISTEST=yes
}}}

For paid-for software publisher certificates (SPC) you'd use something like this:

{{{
set CODESIGN_PKCS12="c:\Users\John\tap-windows\my-software-publisher-certificate.p12"
set CODESIGN_PASS=mypassphrase
set CODESIGN_ISTEST=no
set CODESIGN_CROSS="C:\Users\John\tap-windows\ca-cross-certificate.crt"
set CODESIGN_TIMESTAMP="http://timestamp.domain.com"
}}}

If you imported the kernel-mode code-signing certicate using Internet Explorer, you can use ''certmgr.exe'' to export it in PFX (=PKCS12) format. Just make sure to include the private key in the file and to give it a sufficiently strong password, which you then define using ''CODESIGN_PASS'' variable. The CA cross certificate can be obtained from your CA and most likely needs no modifications. The URL for the timestamping service is CA-specific, but trivial to locate.

Next you configure the tap-windows build to use these using a Visual Studio command prompt:

{{{
> configure
}}}

This copies the variables to ''tap-windows\config-env.bat'', which is included during build. All that's left is to build the tap-windows drivers:

{{{
> build
}}}

Further customization for MSVC can be done using ''config-local.m4'' file which overrides variables or with environment variables which override auto detection code. This can be used, for example, to specify a custom DDK location. For details, see

{{{
> configure --help
}}}

= Code-signing =

The [http://sourceforge.net/projects/osslsigncode/ osslsigncode] tool is used to sign OpenVPN installer, libraries and executables. [http://msdn.microsoft.com/en-us/library/windows/desktop/aa387764%28v=vs.85%29.aspx SignTool] is used to sign the TAP-drivers. Official OpenVPN releases will be signed with  OpenVPN Technologies, Inc. code signing keys. However, it's fairly easy to build a custom version of OpenVPN and sign it with your own code-signing keys.

You need a recent version of osslsigncode (1.4+) for signing, although earlier versions can be used with minor modifications to the codesign() method in the scripts. More specifically, the assumption is that a pkcs12 keystore is used for signing, and osslsigncode 1.3 and earlier don't support pkcs12 yet. After [http://sourceforge.net/projects/osslsigncode/ fetching osslsigncode], make sure you have OpenSSL and Curl3 development libraries installed. On Ubuntu 12.04 you'd do

{{{
$ apt-get update
$ apt-get install libssl-dev libcurl4-openssl-dev
}}}

The latter is used for timestamping support. Extract the osslsigncode tarball and issue the usual commands:

{{{
$ ./configure
$ make
$ sudo make install
}}}

This will put osslsigncode in PATH where the build system can find it.

If you have code-signing certificates generated with MS tools (.spc and .pvk files), you can convert them into standard (pkcs12) format using [attachment:spc+pvk-to-p12.sh this script]. If that fails, look at this [wiki:BuildingUsingGenericBuildsystem@51 old version of this page] for manual instructions.

You can also create ''self-signed'' certificate for testing like this: 

{{{
$ openssl req -newkey rsa:1024 -new -x509 -subj "/CN=test1" -out test.crt	
$ openssl pkcs12 -export -inkey privkey.pem -in test.crt -out test.p12	
}}}

Once you have the pkcs12 archive, you can give it and it's password as argument to the buildsystem(s). For details, look here:

 * [wiki:BuildingUsingGenericBuildsystem#CreatingaNSISinstallerwindows-nsissubdir Building Windows NSIS installer]
 * [wiki:BuildingUsingGenericBuildsystem#BuildingTAP-Windows Building tap-windows]

= Making the release builds of OpenVPN =

We've now described building the various components of OpenVPN in isolation. In this chapter we put all of it together.

== Building signed Windows installers and executables ==

Building Windows executables and installers is one of the most painful parts of OpenVPN release process due to code-signing requirements etc. To generate universally useful installers you need the following:

 * Code-signing (=SPC) certificates
  * Kernel-mode code-signing certificate
  * CA's cross-certificate for kernel-mode code-signing
  * User-mode code-signing certificate (a.k.a. Microsoft Authenticode certificate)
 * A Windows build computer (for building and signing tap-windows)
 * *NIX build computer (for building and signing everything else)
 * Lots of patience

The build process is ''fairly'' straightforward:

 * Get the SPC certificates from a CA
 * Copy the kernel-mode and cross-certificates to the Windows build computer
 * Copy the user-mode code-signing certificate to the *NIX build computer
 * Generate an ''easy-rsa'' tarball and put it on a webserver
 * Generate an ''openvpn-gui'' tarball:
  * [http://sourceforge.net/scm/?type=git&group_id=248281 Clone] the [http://sourceforge.net/projects/openvpn-gui/ new openvpn-gui] git repository
  * Edit ''openvpn-gui/configure.ac'' to change the version number
  * Run ''autoreconf -vif'' in the ''openvpn-gui'' directory
  * Run ''make dist'' in the ''openvpn-gui'' directory to produce tarball.
  * Put the resulting archive on a webserver
 * Optionally, build ''tap-windows'' and put the latest installer on a webserver
 * Setup ''openvpn-build/generic/build.vars'' to suit your needs:
  * dependency locations
  * build flags
 * Setup ''openvpn-build/windows-nsis/build-complete.vars'' to suit your needs:
  * ''easy-rsa'' tarball location
  * ''tap-windows'' installer location
 * Ensure your mingw-w64 installation is up-to-date and/or patched
 * Build the whole thing using ''openvpn-build/windows-nsis/build-complete''
  * '''NOTE:''' ''build-snapshot'' is meant for building ''snapshots'', not release packages 

See corresponding sections for more detailed documentation.

= External links =

'''Official OpenVPN Git repositories'''

 * https://github.com/OpenVPN/openvpn
 * https://github.com/OpenVPN/openvpn-build
 * https://github.com/OpenVPN/tap-windows
 * https://github.com/OpenVPN/easy-rsa

'''Unofficial Git repositores'''

 * https://github.com/mattock/openvpn-build (openvpn-build with Debian and RPM packaging files, documentation [wiki:CreatingUnixPackages here])