A stock Moonlight client can now drive the headless Sway desktop: mouse
movement, buttons, scroll, and keyboard all inject through the streamed
session (verified live end-to-end — typing, clicking, window management).
Control stream (gamestream/control.rs):
- Moonlight encrypts the ENet control stream with AES-128-GCM even though we
negotiate no media encryption (it detects our Sunshine `state` and turns it
on). Decrypt per-packet under the /launch `rikey`.
- The exact GCM scheme is auto-detected on the first authenticating packet
(nonce construction × key byte-order × tag position × AAD) since GCM gives no
partial credit. Our client uses the legacy 16-byte nonce (`iv[0]=seq&0xff`)
because we advertise no encryption; the 12-byte SS_ENC_CONTROL_V2 nonce is
also supported. Key/IV/tag layout cross-checked against Sunshine stream.cpp +
crypto.cpp and moonlight-common-c ControlStream.c.
Input decode (gamestream/input.rs):
- Decrypted control messages (`[u16 type][u16 len][NV_INPUT packet]`, type
0x0206) decode into lumen_core::input::InputEvent: relative/abs mouse, buttons,
vert/horiz scroll, keyboard down/up. Struct layout from moonlight Input.h
(size BE, magic LE, body BE; keyCode LE masked to the low-byte VK), dispatch
per Sunshine input.cpp (Gen5+). Unit-tested against real captured bytes.
Injection (inject.rs):
- WlrootsInjector: connects to Sway as a Wayland client and injects via the
wlroots virtual-pointer + virtual-keyboard protocols (uinput is invisible to a
compositor running WLR_LIBINPUT_NO_DEVICES=1). Uploads an evdev/US xkb keymap,
tracks modifier state, and maps Windows VK → Linux evdev (full table).
Deps: aes-gcm, wayland-client, wayland-protocols-{wlr,misc}, xkbcommon (+
libxkbcommon-dev in bootstrap-ubuntu.sh).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
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