libjuice - UDP Interactive Connectivity Establishment
libjuice 🍋💦 (JUICE is a UDP Interactive Connectivity Establishment library) allows to open bidirectionnal User Datagram Protocol (UDP) streams with Network Address Translator (NAT) traversal.
The library is a simplified implementation of the Interactive Connectivity Establishment (ICE) protocol, client-side and server-side, written in C without dependencies for POSIX platforms (including GNU/Linux, Android, Apple macOS and iOS) and Microsoft Windows. The client supports only a single component over UDP per session in a standard single-gateway network topology, as this should be sufficient for the majority of use cases nowadays.
libjuice is licensed under LGPLv2, see LICENSE.
libjuice is available on AUR and vcpkg.
For a STUN/TURN server application based on libjuice, see Violet.
Compatibility
The library implements a simplified but fully compatible ICE agent (RFC8445, RFC8489 for STUN, and RFC8656 for TURN) with an interface based on SDP (RFC4566). It supports both IPv4 and IPv6.
The limitations compared to a fully-featured ICE agent are:
- Only UDP is supported as transport protocol. Other protocols are ignored.
- Only one component is supported. This is sufficient for WebRTC Data Channels or multiplexed RTP/RTCP (RFC5731).
- Candidates are gathered without binding to each network interface, which behaves identically to the full implementation on most client systems.
It also implements a lightweight STUN/TURN server (RFC8489 and RFC8656). The server can be disabled at compile-time with the NO_SERVER
flag.
Dependencies
None!
Optionally, Nettle can provide SHA1 and SHA256 algorithms instead of the internal implementation.
Building
Clone repository
$ git clone https://github.com/paullouisageneau/libjuice.git
$ cd libjuice
Build with CMake
The CMake library targets libjuice
and libjuice-static
respectively correspond to the shared and static libraries. The default target will build the library and tests.
POSIX-compliant operating systems (including Linux and Apple macOS)
$ cmake -B build
$ cd build
$ make -j2
The option USE_NETTLE
allows to use the Nettle library instead of the internal implementation for HMAC-SHA1:
$ cmake -B build -DUSE_NETTLE=1
$ cd build
$ make -j2
Microsoft Windows with MinGW cross-compilation
$ cmake -B build -DCMAKE_TOOLCHAIN_FILE=/usr/share/mingw/toolchain-x86_64-w64-mingw32.cmake # replace with your toolchain file
$ cd build
$ make -j2
Microsoft Windows with Microsoft Visual C++
$ cmake -B build -G "NMake Makefiles"
$ cd build
$ nmake
Build directly with Make (Linux only)
$ make
The option USE_NETTLE
allows to use the Nettle library instead of the internal implementation for HMAC-SHA1:
$ make USE_NETTLE=1
Example
See test/connectivity.c for a complete local connection example.
See test/server.c for a server example.