Comment by gleenn
16 hours ago
Works until AI compromises a bunch of OSes. And wouldn't there be difficulty comparing binaries built from significantly different environments? It sounds like some progress has been made in general for fixed identical builds, but isn't that also still a hard problem? I don't know enough low level C-level stuff about binary generation.
> Works until AI compromises a bunch of OSes.
Just write a new OS. It's a weekend project to get enough groundwork that you can bootstrap a clean system from clean source code.
> And wouldn't there be difficulty comparing binaries built from significantly different environments?
Not really. Starting from stage 0, compile the compiler under test (stage 1), then use the compiled compiler to compile the compiler (stage 2), and compare the stage 2 artefacts. Provided that your comparison program is known-good, and the stage 2 build is deterministic (not the case for some real-world programs, but true for things like tcc), this lets you verify that the two compilation procedures work identically.
Not sure if you're joking. How do you write an OS without these tools that might be compromised? It's the same problem.
Break expectations. Bootstrap it through an esoteric-enough system. Write an Uxn emulator in assembly targeting the cushy environment that UEFI has and you've got a system with graphics, a text editor, a spreadsheet editor, an assembler, games, and maybe even more. I have a Z80-powered email appliance that can be loaded with programs from a connected device. Whoever is breaking my trust in trust surely won't have planned for that.
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You can construct a CPU out of an EEPROM, a clock, and a few latches. Connect it to an immediate mode display with a serial interface that doesn't care about being clocked slowly, connect up a buzzer or some blinkenlights for output when you're exceptionally paranoid and can't trust the display controller, make a basic keyboard with a rubber sheet, some wire, and some glue, poke a keyboard driver and a line editor into memory with your DIP switches, crank the clock up to kilohertz (so the keyboard latency is tolerable), and you too can bootstrap a cross-compiler! (Though be aware that the radio interference will be enough for a committed attacker to figure out what you're computing, unless you take measures against that.)
But they're not going to backdoor an Apple ][e, or a random 80m¢ microcontroller, for basically any value of "they"; so you can just use one of those instead, and save yourself the hassle.
Write a subleq interpreter with a magnet and a steady hand? (Hopefully the magnet is not compromised)
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We have tons and tons of backups of clean Linux isos, compilers, etc. The idea that we are going to lose the ability to easily have an uncompromised system is a fairy tale told by the people pushing bootstrapable builds.