Airlock is a small capability-based operating system for x86-64 PCs, written in Rust from the kernel up. It boots from a USB stick and is built to be useful on untrusted networks without quietly becoming part of them.
No Linux underneath: its own kernel, scheduler, network stack, USB stack, desktop and drivers.
prime included.While LOCKED, Airlock transmits nothing at all: no ARP, DHCP, ICMP replies, TCP, Wi-Fi probes or authentication frames. Incoming traffic can still be observed and parsed. Transmission is blocked in software and, on supported Ethernet hardware, by turning the transmitter off.
| LOCKED | OPEN | |
|---|---|---|
| Receive and inspect traffic | yes | yes |
| Transmit frames | no | yes |
| DHCP / DNS / ping / outbound TCP | no | yes |
| Join Wi-Fi | no | yes |
| Listen for incoming connections | no | no |
The test suite checks the property from captured wire traffic, not from the kernel's own counters.
Every program runs in Ring 3 in its own address space and holds named capabilities with specific rights. A process can narrow what it holds but never widen it, and the administrative user gets no bypass. Policy and services keep moving out of the kernel.
W^X audited at boot, SMEP and SMAP where supported, one hardware thread per physical core by default, and bus-mastering devices without a driver are quiesced.
Each link checks the next. Programs in /bin are read from the boot stick when first run and refused unless their SHA-256 matches the manifest. Images are reproducible when the build time is pinned.
Tests break links in the chain on purpose and require the boot to stop or the program to be refused.
The kernel, drivers, network stack, desktop, page layout and TLS are Airlock's own code. Stylo, Boa and the compilers are ported to run on it. Airlock runs on two ThinkPads and in QEMU/OVMF, and it is self-hosting: rustc and Cargo build Rust programs on Airlock itself.
main
T490s verified on the reference laptop
prime administrator bypasses nothing/bin program hash-checked when first run/data and remembered networks/tmp in memory, with logs that have secrets taken outsrcset/bin programs with their own grantsa | b$?, environmenthwinfo for devices, events and ACPIstd for Airlock, and the native linker airlock-ldHardware: UEFI through Limine · ACPI tables and an AML namespace checked against ACPICA · PCI · xHCI with hubs and hotplug · PS/2 and USB keyboards · Intel 8254x, 82574L and I219 Ethernet · Intel HD Audio · battery, AC, lid, power button and backlight · ThinkPad T490s and T460s
Every change runs against QEMU guests in parallel: pixel-exact GUI checks, deliberate faults, fuzzed system calls and parsers, and the network lock watched on the wire. Nothing is called done until the full suite passes.
Airlock is a hobby operating system under active development, not a security-audited production system. Its security properties are meant to come from explicit boundaries and tests, not from obscurity.