enricobuehlerandClaude Opus 5
d383161723
~1150 feat/fix commits landed since v0.19 and the docs drifted badly. This is a full sweep of every page against the code as shipped: ~280 verified corrections, nine new pages, and one deletion. The worst of what was wrong: the quickstart's five-minute path could not work (`serve` never started the web console, so step 3 had no PIN to read); every packaged Linux host runs `serve --gamestream` while security.md told readers to leave GameStream off; HDR was documented as Windows-only; `PUNKTFUNK_SECURE_DDA` was documented as a working knob that nothing reads; `PUNKTFUNK_INPUT_BACKEND` listed a `uinput` value that does not exist and named libei for KDE instead of kwin; README linked three pages deleted on 2026-07-05; and the rpm-ostree update command pointed at a script no package installs. Completeness: about half of what shipped since v0.19 had no page at all. New: support-matrix (what works where, from 217 verified capability cells), input (mouse/touch/pen — and the in-stream chords, so the docs finally say how to get your mouse back), client-settings, profiles-and-links, game-library, clipboard, wake-on-lan, hdr, uninstall. Updating existed but had zero inbound links. status.md is gone: its facts moved into the support matrix, its shell stays as a redirect so the public URL does not 404. roadmap.md is themes now, not a feature checklist — checkboxes are what rotted. Debian is no longer claimed. The .deb's Depends resolve against Ubuntu images, nothing in CI builds or tests Debian, and Debian 12 is below the glibc 2.39 floor. The `debian` in the repo URL is the package format. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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title, description
| title | description |
|---|---|
| Pairing & Trust | How a client and host establish trust — PIN pairing once, pinned reconnects after. |
Punktfunk has no accounts and no cloud. Trust is established directly between a client and a host, on your network, with a one-time pairing — either an approval click in the host's web console or a PIN ceremony. After that, the device reconnects automatically on a pinned cryptographic identity.
How it works
- Each host has a stable identity (a certificate). Clients remember its fingerprint, so they know they're talking to the same host next time.
- The first time a client connects, you pair it: with the native protocol the host shows a short 4-digit PIN and you type it into the client. (With Moonlight it runs the other way round — Moonlight shows the PIN and you type it into the host's console.) Either way a secure exchange (SPAKE2) binds the two identities, and an attacker who doesn't know the PIN gets a single online guess — no offline cracking.
- After pairing, the host stores the client's identity in its allow-list, and the client stores the host's fingerprint. Reconnects are automatic — no PIN. Having seen the host on your network while it was awake also teaches the client its MAC address, so a later connect can wake it from sleep.
Approving a device from the console (no PIN)
The fastest way to admit a new device: just try to connect from it. On a pairing-required host, the attempt shows up in the web console's Pairing page under Waiting for approval — with the device's name and identity fingerprint. Click Approve (and optionally give it a label like "Living Room TV"), and the device is paired on the spot: its next connect goes straight through. No PIN to read or type.
Deny just dismisses the request (the device can knock again later — it's "not now", not a blocklist). Requests expire on their own after 10 minutes.
This works because approval happens on the host's authenticated management surface — only someone with console access can admit a device.
Pairing with a PIN
PIN pairing is the default and required path for any new host: unless the host has explicitly opted into trust-on-first-use (see below), a client connecting to an unknown host must complete the PIN ceremony — or be approved from the console, as above — before it can stream. It's the right path for the first device (before the console has admitted anything) or when you're at the client and the console isn't handy.
Pairing has to be armed on the host before a client can pair (so a random device can't pair
itself). On the production host (serve), this is done from the web console: open the
host's management console, click to arm pairing, and the host displays a 4-digit PIN along with the
list of paired devices. This works on a headless host over the network — there is no command-line flag
to arm pairing on serve.
The armed window lasts 2 minutes — the console counts it down under the PIN and offers a Cancel button. Arm it once you're standing at the device; if it lapses, just arm it again.
Pairing from the console needs the console running. On Linux that's the separate punktfunk-web
systemd user unit, which you enable once — see The Web Console.
Then, on the client:
- Native clients (Apple, Linux, Windows, Android): select the host (or use Pair with PIN… from its menu) and enter the PIN the host displays.
- Steam Deck (the Decky plugin): open Punktfunk from the Quick Access menu and pick the host — an unpaired one's button reads Pair & Stream. Enter the PIN on the 4-digit pad it opens.
- Moonlight: choose Pair; Moonlight shows a 4-digit PIN, and you type that PIN into the console's Moonlight (GameStream) pairing card and press Submit PIN. (This direction is the reverse of the native flow, and arming doesn't apply to it.)
A link can't stand in for any of this. A
punktfunk:// link starts a stream on a
host this device already trusts; punktfunk://pair/… is refused outright, and a link naming a host
you've never paired with can at most open the app's own trust prompt.
Pairing from a terminal
On Linux the client package also installs punktfunk, a headless CLI. Arm pairing in the console,
read the PIN, then run:
punktfunk pair 192.168.1.50 --pin 1234 --name "Living Room"
It prints paired <addr>:<port> fp=<fingerprint> and saves the host in the same store the desktop
client uses, so later connects are silent. --name is the label the host files this device under
(default: this machine's name), and the port defaults to 9777 — write host:port to use another
one. Without --pin the command asks for one; in a script with no terminal it exits 6 rather
than hanging, and exit 3 means the host refused or the PIN was wrong.
The GTK client can do the same thing without opening a window:
punktfunk-client --connect 192.168.1.50:9777 --pair 1234 --name "Living Room"
Requiring pairing (the default)
By default, the native host requires pairing — only devices that have paired can stream. This is the right setting on a shared network: a device has to complete the PIN ceremony once before it can connect.
If you're on a fully trusted single-user network and want to skip pairing, run the host open with
serve --open — it then advertises pair=optional and accepts unpaired clients. Requiring pairing
is strongly recommended.
Trust-on-first-use (host opt-in)
Trust-on-first-use (TOFU) is off by default and is an explicit host opt-in for fully trusted
networks. A host enables it by running open — serve --open — which makes it advertise
pair=optional over mDNS and accept unpaired clients. Only then does a client offer the
TOFU path: connecting to such a host for the first time shows the host's fingerprint and asks you to
confirm it (compare it with the one the host logged at startup), then pins it. The client presents
this clearly as the reduced-security option, alongside Pair with PIN.
Warning: TOFU cannot detect an impostor on the first connection — if someone is impersonating the host the very first time you connect, you'll pin the attacker's fingerprint. PIN pairing closes that gap (the SPAKE2 ceremony binds both identities), which is why it's the default. Use TOFU only on a network you fully trust — see Security & Safe Use.
For every other case — a host advertising pair=required (the default), a host you typed in by hand,
or a discovered host whose pair policy is unknown — TOFU is not offered and the client routes straight
to the PIN ceremony.
Once a host is pinned, a fingerprint change is treated as the impostor signal: the client forces re-pairing through the PIN ceremony rather than offering to re-trust the new identity.
Managing paired devices
The web console lists every paired device and lets you remove one (revoking its access). Re-pairing is just the PIN ceremony again.
If a client can't pair at all, see Troubleshooting → Pairing is rejected.
(There is also a developer/measurement host, punktfunk-host punktfunk1-host — a subcommand of the
same binary, not the host you install. It has its own --allow-tofu / --pairing-pin flags for test
harnesses; nothing on this page applies to it.)