1 Requirements

1.1 Operating system

Linux:
- Linux kernel 2.6. Kernel 2.4 will work, but performance will suffer.
- tested on x86, x86_64 and ARM architectures. Not tested on any big-endian architecture.

Windows:
- Windows XP or newer; tested on Windows XP and Windows 7

FreeBSD:
- Not regularly tested.

Other systems are not supported.

1.2 Compilers

Linux:
  - gcc
  - clang, except >=3.0 (clang bug http://llvm.org/bugs/show_bug.cgi?id=11535)

Windows:
  - gcc from the mingw-w64 project for 32-bit targets

C language features used:
  - Standard (all part of C99):
    - designated initializers
    - stdint.h, inttypes.h, stddef.h
    - intermingled declarations and code
    - for loop initial declaration
    - one-line "//" comments
  - Extensions:
    - packed structure attribute (to pack a structure and allow unaligned access)

1.3 CMake

The build system uses CMake.

1.4 OpenSSL

Libcrypto (part of OpenSSL) is used for block ciphers, hash functions and random data generation.

1.5 Network Security Services (NSS)

The NSS library from Mozilla is used for TLS support. NSS command-line tools are also needed
for setting up certificates.

1.6 TAP-Win32 (Windows only) (runtime only)

The TAP-Win32 driver, part of OpenVPN.

2 Compilation

2.1 Compiling on Linux

$ tar xf badvpn-<version>.tar.bz2
$ mkdir build
$ cd build
$ cmake ../badvpn-<version> -DCMAKE_INSTALL_PREFIX=/usr/local
$ make
If you want to install it, run as root:
# make install

If you only want NCD or tun2socks and not the VPN system, you can avoid the NSS dependency by passing
the following to the cmake command:
-DBUILD_NCD=1 -DBUILD_TUN2SOCKS=1 -DBUILD_NOTHING_BY_DEFAULT=1

2.2 Compiling for Windows

See the file INSTALL-WINDOWS for detailed instructions.

3 Usage

The primary documentation is on the BadVPN homepage, http://code.google.com/p/badvpn/ .
Additionally, some man pages are installed (badvpn(7), badvpn-server(8), badvpn-client(8)).