Johnathan Corgan
aa204cf729
The rekey marker's cross-connection arm declined to swap while a rekey of ours was in flight, reasoning that the swap rewrites the session and both indices while touching no rekey state, so it would orphan that rekey. The reasoning was one-sided and the arm was wrong: this is half of a two-sided tie-break whose other half reads only whether a peer exists and the address ordering, and cannot see our rekey. Declining here while the peer's outbound half swaps anyway leaves the two ends on four distinct indices with neither holding a pending session, dead both directions until the link-dead timer. Measured against the pre-marker tree, which converges: it holds the crossing dial as pending and adopts it at cutover. The orphaned-rekey hazard is real but belongs to the executor. The swap now abandons the rekey it displaces and frees that index first, exactly as the rekey-responder path already does when it loses the dual-rekey tie-break, so the classifier can take the arm unconditionally. Two further failure paths of the marker are tightened. A malformed marker tore the handshake down without freeing the index msg1 allocated, and that arm sits ahead of the ACL gate, so any peer able to complete a msg3 could grow the allocator set one entry at a time. A rekey with no session index to declare silently omitted the marker, which puts a real rekey back on the cross-connection path; it is unreachable today and is now asserted rather than skipped. On the test side, the marker's wire contract gains coverage: the accessor round-trips, an unknown TLV field leaves it alone in both directions, and a well-formed marker of the wrong length is an error rather than an absence, which is the case the container codec cannot see and the whole reason the accessor is fallible. Two node-level tests now assert both ends rather than one. A rekey fired by message count on a zero-age session is the mechanism behind the datagram drops, and nothing exercised it: it fails on the pre-marker tree and passes here. The mutual-dial test gains an index-pair assertion, since every per-end predicate it checked holds when the ends have diverged. One existing test had stopped reaching its own arm. Driving a bare second handshake into a rekey-disabled peer now lands on the cross-connection arm, which that flag does not gate, and every assertion held there too; it is retargeted onto a declared rekey, which is the real route to the duplicate arm, and asserts the session is left alone so the two arms are told apart. Documentation that described the removed session-age floor is rewritten around the declaration.
FIPS: Free Internetworking Peering System
A self-organizing encrypted mesh network built on Nostr identities, capable of operating over arbitrary transports without central infrastructure.
FIPS is under active development. The protocol and APIs are not yet stable. See Status & roadmap below.
What FIPS does
A machine running FIPS becomes a node in the mesh with a self-generated cryptographic identity (a Nostr keypair). There are two equally-supported deployment modes.
As an overlay on top of existing IP networks, FIPS lets your node reach any other FIPS node wherever it sits — behind a NAT, on a different ISP, on a phone over cellular, on a laptop with only Bluetooth in range, or behind a Tor onion. The mesh forwards IPv6 traffic transparently and end-to-end encrypted, with no central VPN concentrator or coordinating server.
Ground up over raw Ethernet, WiFi, or Bluetooth, FIPS provides a complete permissionless network without any pre-existing IP infrastructure, ISP, or DNS. Any node that joins the link gets routable IPv6 addresses, peer discovery, and a path to every other node automatically.
Either way, existing networking software runs over it unchanged — SSH, HTTP servers, file transfer, anything IPv6-native works the same way it would on a local network.
Features
- Self-organizing mesh routing. Spanning-tree coordinates with bloom-filter-guided discovery; no global routing tables, no flooding.
- Multi-transport. UDP, TCP, Ethernet, Tor, Nym, and Bluetooth (BLE L2CAP) ship today; transports compose on a single mesh and a node may run several at once.
- Two-layer encryption. Noise XX both hop-by-hop (peer links) and end-to-end (mesh sessions), with periodic rekey for forward secrecy and protocol negotiation in the handshake.
- Nostr-native identity. secp256k1 / schnorr keypairs as node addresses; self-generated, no registration, no central authority.
- IPv6 adapter. A TUN interface maps each remote npub to an
fd00::/8address, so unmodified IPv6 software reaches mesh peers as<npub>.fips. Built-in.fipsDNS resolver, with optional static name mapping via/etc/fips/hosts. - Nostr-mediated discovery and NAT traversal. Peers publish endpoint adverts on public Nostr relays, exchange candidates via NIP-59 gift-wrapped offers and answers, and establish direct paths through NATs using STUN-assisted hole punching. On the local network, mDNS LAN discovery finds peers directly without relays.
- LAN gateway. Optional
fips-gatewayservice folds an entire unmodified LAN into the mesh: outbound (LAN clients reach mesh destinations through a DNS-allocated virtual IPv6 pool and nftables NAT) and inbound (LAN-side services exposed to the mesh through 1:1 port forwards). - Per-link metrics. RTT, loss, jitter, and goodput on every hop, plus mesh-size estimation, via the Metrics Measurement Protocol.
- ECN congestion signaling. Hop-by-hop CE-flag relay with RFC 3168 IPv6 marking and transport kernel-drop detection.
- Mesh-interface security baseline. Optional default-deny
nftables policy for
fips0shipped as a packaged conffile (/etc/fips/fips.nft) with an operator drop-in directory (/etc/fips/fips.d/) and a disabled-by-defaultfips-firewall.service. The baseline polices only the mesh interface, leaving Docker, Tor, and the host firewall untouched. - Operator visibility.
fipsctlCLI for control and inspection with time-series stats history queryable for any metric,fipstopTUI for live status with inline sparkline dashboards, and a JSON-line control socket on each binary for direct programmatic access. - Reproducible builds with toolchain pinning and
SOURCE_DATE_EPOCH.
Quick start
The shortest path on Debian / Ubuntu:
git clone https://github.com/jmcorgan/fips.git
cd fips
cargo install cargo-deb
cargo deb
sudo dpkg -i target/debian/fips_*.deb
sudo systemctl start fips
This installs the daemon, CLI tools (fipsctl, fipstop), the
optional fips-gateway service, systemd units, and a default
/etc/fips/fips.yaml you can edit before starting.
For macOS, Windows, OpenWrt, the systemd tarball, a Nix flake, or a from-source build, see docs/getting-started.md for the full multi-platform installation guide.
To join a live mesh and reach your first peer, follow the new-user tutorial progression starting at docs/tutorials/join-the-test-mesh.md.
Building from source
cargo build --release
Requires Rust 1.94.1+ (edition 2024). Linux, macOS, and Windows run as
standalone daemons; Android is supported as an embedded library (the host
app owns the TUN, e.g. a VpnService). Transport availability varies by
platform.
| Transport | Linux | macOS | Windows | Android | OpenWrt |
|---|---|---|---|---|---|
| UDP | ✅ | ✅ | ✅ | ✅ | ✅ |
| TCP | ✅ | ✅ | ✅ | ✅ | ✅ |
| Ethernet | ✅ | ✅ | ❌ | ❌ | ✅ |
| Tor | ✅ | ✅ | ✅ | ❌ | ✅ |
| Nym | ✅ | ✅ | ✅ | ❌ | ❌ |
| BLE | ✅ | ❌ | ❌ | ❌ | ❌ |
On Linux, a source build requires libclang — the LAN gateway's
nftables bindings are generated by bindgen at build time, which
needs libclang.so on the build host. Install it before building
(sudo apt install libclang-dev on Debian / Ubuntu); without it the
build fails inside the rustables crate with an "Unable to find
libclang" error. This is a build-time prerequisite only — it is not a
runtime dependency, and the pre-built .deb artifacts do not need it.
BLE is optional and, on Linux, requires BlueZ and libdbus
(sudo apt install bluez libdbus-1-dev on Debian / Ubuntu). It is
gated on a build-script probe — install the dependencies first and
the cargo build line above picks it up. The OpenWrt ipk omits
BLE because libdbus is not available on the target.
Nym (mixnet) transport builds on all desktop platforms. The OpenWrt
❌ is provisional, pending verification of nym-socks5-client
availability on the target; it will flip to ✅ only if confirmed
buildable there.
Alternatively, the repo ships a Nix flake: nix develop
drops you into a shell with the pinned toolchain and every build
prerequisite (libclang, dbus, pkg-config) already provided, and
nix build .#fips builds all four binaries with no host setup. See the
Nix / NixOS section of packaging/README.md.
Documentation
docs/ is organised by reader purpose:
- Tutorials — hand-held walk-throughs from a fresh install through to a participating mesh node, plus advanced deployments (gateway on OpenWrt, hosting services, ground-up two-device mesh).
- How-to guides — operator recipes for specific tasks: firewall activation, Nostr discovery, Tor onion service, Bluetooth peering, LAN gateway deployment and troubleshooting, MTU diagnostics, host aliases, persistent identity, unprivileged-user setup, UDP buffer tuning.
- Reference —
fips.yamlconfiguration, wire formats, control-socket protocol, CLI references for each binary, security posture matrix, Nostr events catalog, transport statistics inventory. - Design — protocol-level architecture and layer specifications. Start with fips-concepts.md for the framing, then fips-architecture.md for the protocol stack.
If you want to contribute, see CONTRIBUTING.md and testing/README.md.
Examples
- examples/sidecar-nostr-relay/ — Run a strfry Nostr relay reachable exclusively over the FIPS mesh. The relay container shares the FIPS sidecar's network namespace and is isolated from the host network.
- examples/sidecar-nostr-mixnet-relay/ — Single-container demo of FIPS peering through a mixnet (implemented with Nym): the FIPS daemon, the mixnet proxy, and a strfry Nostr relay all in one isolated container, with the direct route to the peer firewalled off so traffic provably crosses the mixnet.
- examples/k8s-sidecar/ — Run FIPS as
a Kubernetes Pod sidecar. The sidecar creates
fips0in the Pod's shared network namespace so every other container in the Pod gets mesh access without modification. - examples/wireguard-sidecar-macos/ —
Reach the FIPS mesh from a macOS host through a local Docker
container over a WireGuard tunnel. Only traffic destined for
fd00::/8transits the sidecar; regular internet traffic continues to use the host network.
Project structure
src/ Rust source: library + fips, fipsctl, fipstop, fips-gateway binaries
docs/ Documentation: tutorials, how-to, reference, design
packaging/ Debian, macOS .pkg, Windows ZIP, OpenWrt ipk, AUR, systemd tarball
examples/ Deployment examples (Nostr relay, K8s sidecar, macOS WireGuard)
testing/ Docker-based integration test harnesses + chaos simulation
Status & roadmap
FIPS is at v0.6.0-dev on the next branch.
v0.4.1
has shipped from master; this development line carries
wire-format-breaking work for v0.6.0 — unified Noise XX handshake
at both layers, FMP node profiles, slimmer MMP reports, and an
extensible bloom-filter encoding — that will not interoperate with
v0.2.x, v0.3.x, or v0.4.x peers. The core protocol works end-to-end over
UDP, TCP, Ethernet, Tor, Nym, and Bluetooth on a global, public test
mesh of thousands of nodes. See the CHANGELOG ## Breaking section for the
full list of v0.6.0 wire-format changes in flight.
What works today
- Spanning-tree construction with greedy coordinate routing.
- Bloom-filter-guided destination discovery (no flooding, single-path with retry).
- Two-layer Noise XX encryption (hop-by-hop at the link layer and end-to-end at the session layer) with periodic hitless rekey for forward secrecy at both layers and protocol negotiation in the handshake.
- Persistent or ephemeral node identity with key-file management.
- IPv6 TUN adapter with built-in
.fipsDNS resolver and multi-backend auto-configuration (systemd dns-delegate, systemd-resolved, dnsmasq, NetworkManager). - Static hostname mapping (
/etc/fips/hosts) with auto-reload. - Per-link metrics (RTT, loss, jitter, goodput) and mesh size estimation.
- ECN congestion signaling (hop-by-hop CE relay, IPv6 CE marking, kernel-drop detection).
- UDP, TCP, Ethernet, Tor, Nym (mixnet), and BLE transports (BLE via L2CAP CoC with per-link MTU negotiation).
- Nostr-mediated overlay endpoint discovery and UDP hole punching for NAT traversal, plus mDNS LAN discovery for local peers.
- LAN gateway (
fips-gateway) with both outbound (LAN-to-mesh) and inbound (mesh-to-LAN port-forwarding) modes. - Peer ACL: per-npub allow / deny admission control at the link
layer; opt-in mesh-firewall baseline at
fips0ingress. - Runtime inspection and peer management via
fipsctlandfipstop. - Reproducible builds with toolchain pinning and
SOURCE_DATE_EPOCH. - Linux (Debian, systemd tarball, OpenWrt, AUR), macOS (
.pkg), and Windows (ZIP, service) packaging. - Docker-based integration and chaos testing.
Near-term priorities
- Native API for FIPS-aware applications (npub:port addressing without the IPv6-shim path).
- Security audit of the cryptographic protocols.
Longer-term
- Mobile platform support.
- Bandwidth-aware routing and QoS.
- Protocol stability and a versioned wire format.
- Published crate.
License
MIT — see LICENSE.