Security policy

Reporting a vulnerability

Open a security advisory on this repository, which is private until published. If that is unavailable to you, open a normal issue saying only that you have a security report and asking for a contact — do not put the details in a public issue.

There is no bug bounty. This is a public-domain project maintained by volunteers, so expect a reply in days rather than hours.

What is useful in a report, roughly in order:

1. What an attacker gains, and what they need to start — "any peer on the medium, one packet, no key" is a very different report from "a session partner, over hours".
2. A reproduction. A failing test or a byte sequence beats a description of a code path, because several plausible readings of this code have turned out to be already handled — see Investigated and not a finding.
3. Which file and function.

Every accepted finding is written up in docs/SECURITY_FINDINGS.md with its reproduction, root cause, patch, and the test that keeps it fixed. You are welcome to be credited there or not, as you prefer.

What is in scope

The protocol and its implementations: the Rust core, the bridges, the wasm/browser node, the C ABI and its language bindings, and the Android app. Also in scope, and treated as real findings rather than documentation nits:

• A claim in the docs that the code does not honour. Two of the findings on record are exactly this — an offline build that could not run offline, and a minimum Rust version that could not compile the project. A promise nobody has executed is a defect, because someone will rely on it in the one situation where they cannot check.
• A test that asserts the wrong thing. One existing test asserted that a nearly-free proof-of-work stamp should bypass congestion control; the assertion encoded the bug.

What is not in scope

• A hostile link. Every bridge is assumed compromised. A link that drops, delays, reorders, duplicates or floods is the design, not a bug — envelopes are signed and sealed end to end and the router survives all of it. What is in scope is a link that makes a node spend unbounded memory, CPU, disk or airtime, or that gets a node to believe something it should not.
• Unsigned mail being forgeable. SPORE permits unsigned envelopes. They are forgeable by anyone and are documented as such; a node that trusts one is misusing the API. That the router can be made to misbehave by one is in scope.
• Metadata visible to a bridge. A bridge sees that traffic happened, its size and its timing. Mix mode reduces this and is not Tor. Per-bridge exposure is documented in docs/BRIDGES.md; an undocumented leak is worth reporting, a documented one is a known limitation.
• 8-byte address collisions. Addresses are 64-bit hashes. A collision is possible with effort, which is why the full public key travels whenever a frame is not SRC8 and why nothing binds an address without a verified signature.

Known limitations, stated plainly

Report these only if you can show something worse than what is written here.

• Hardware-unverified bridges. Anything marked 🧪 in docs/BRIDGES.md has tested codecs and an untested hardware loop. Radio, BLE and audio paths are template-grade until someone runs the procedure in docs/HARDWARE.md on real devices.
• The ratchet and mix layers have had one bounds review, not a cryptographic audit. Nobody has analysed the mix for traffic-analysis resistance beyond its size classes.
• No third-party audit has been performed on any part of this.
• with_node is not reentrant — an embedder whose closure calls back into the hub deadlocks that thread. Documented, not prevented.
• The remaining still-open items are listed at the end of docs/SECURITY_FINDINGS.md. They are carried deliberately and are not secrets.

Supported versions

The v1 wire format is frozen; master is the only supported branch. Fixes land there and reach releases from there — there are no maintained back-branches to backport to.

Operator notes

• The seed is the identity. node.seed(), the Android and wasm persistence APIs, and the invite formats all expose a raw 32-byte secret. Never log it, and treat a device backup containing it as key material.
• Run with the least you need. The ICMP bridge wants CAP_NET_RAW; grant it with setcap on the binary rather than running the node as root.
• Verify what you rebuilt. Releases publish a SHA-256; the offline bundle publishes one too, and the single-file node prints the hash of its embedded wasm in its own footer.