Yggdrasil

Introduction

Yggdrasil is an early-stage implementation of a fully end-to-end encrypted IPv6 network. It is lightweight, self-arranging, supported on multiple platforms and allows pretty much any IPv6-capable application to communicate securely with other Yggdrasil nodes. Yggdrasil does not require you to have IPv6 Internet connectivity - it also works over IPv4.

Although Yggdrasil shares many similarities with cjdns, it employs a different routing algorithm based on a globally-agreed spanning tree and greedy routing in a metric space, and aims to implement some novel local backpressure routing techniques. In theory, Yggdrasil should scale well on networks with internet-like topologies.

Supported Platforms

We actively support the following platforms, and packages are available for some of the below:

• Linux
  • .deb and .rpm packages are built by CI for Debian and Red Hat-based distributions
  • Void and Arch packages also available within their respective repositories
• macOS
  • .pkg packages are built by CI
• Ubiquiti EdgeOS
  • .deb Vyatta packages are built by CI
• Windows
• FreeBSD
• OpenBSD
• NetBSD

Please see our Platforms pages for more specific information about each of our supported platforms, including installation steps and caveats.

Building

If you want to build from source, as opposed to installing one of the pre-built packages:

1. Install Go (requires Go 1.11 or later)
2. Clone this repository
3. Run ./build

Note that you can cross-compile for other platforms and architectures by specifying the GOOS and GOARCH environment variables, e.g. GOOS=windows ./build or GOOS=linux GOARCH=mipsle ./build.

Running

To generate static configuration, either generate a HJSON file (human-friendly, complete with comments):

./yggdrasil -genconf /path/to/yggdrasil.conf

... or generate a plain JSON file (which is easy to manipulate programmatically):

./yggdrasil -genconf /path/to/yggdrasil.conf -json

You will need to edit the yggdrasil.conf file to add or remove peers, modify other configuration such as listen addresses or multicast addresses, etc.

To run with the generated static configuration:

./yggdrasil -useconffile /path/to/yggdrasil.conf

To run in auto-configuration mode (which will use sane defaults and random keys at each startup, instead of using a static configuration file):

./yggdrasil --autoconf

You will likely need to run Yggdrasil as a privileged user or under sudo, unless you have permission to create TUN/TAP adapters. On Linux this can be done by giving the Yggdrasil binary the CAP_NET_ADMIN capability.

Documentation

Documentation is available on our GitHub Pages site, or in the base submodule repository within doc/yggdrasil-network.github.io.

• Configuration file options
• Platform-specific documentation
• Frequently asked questions
• Admin API documentation

Performance

A simplified model of this routing scheme has been tested in simulation on the 9204-node skitter network topology dataset from caida, and compared with results in arxiv:0708.2309. Using the routing scheme as implemented in this code, the average multiplicative stretch is observed to be about 1.08, with an average routing table size of 6 for a name-dependent scheme, and approximately 30 additional (but smaller) entries needed for the name-independent routing table. The number of name-dependent routing table entries needed is proportional to node degree, so that 6 is the mean of a distribution with a long tail, but this may be an acceptable tradeoff (it's at least worth trying, hence this code). The size of name-dependent routing table entries is relatively large, due to cryptographic signatures associated with routing table updates, but in the absence of cryptographic overhead, each entry should otherwise be comparable in size to the BC routing scheme described in the above paper. A modified version of this scheme, with the same resource requirements, achieves a multiplicative stretch of 1.02, which drops to 1.01 if source routing is used. Both of these optimizations are not present in the current implementation, as the former depends on network state information that appears difficult to cryptographically secure, and the latter optimization is both tedious to implement and would make debugging other aspects of the implementation more difficult.

License

This code is released under the terms of the LGPLv3, but with an added exception that was shamelessly taken from godeb. Under certain circumstances, this exception permits distribution of binaries that are (statically or dynamically) linked with this code, without requiring the distribution of Minimal Corresponding Source or Minimal Application Code. For more details, see: LICENSE.