8 ms·

https://www.quora.com/What-is-a-coders-worst-nightmare/answer/Mick-Stute https://www.quora.com/What-is-a-coders-worst-nightmare/answe...

by pliny 8y ago

deleted 8y ago
[deleted]
deleted 8y ago
[deleted]
pmichaud 8y ago
Jesus, that is intense. I wonder if the guy was personally out to get the Doc, or if he was just a smart kid with too much time and not enough superego?
- kazinator 8y ago
  He did make it super easy to find this by having the compiler modify source code. If you run "cc file.c" and file.c is overwritten, you should know that it's the "cc" doing it. It would have been more evil to do it the original way, as described in Thompson's paper: recognize the program sources and emit altered object code only; no mucking with the source.
- rexpop 8y ago
  Interesting that the first adjective you use was "smart" when, in any decent scope of consideration, he has actually wasted many hours of others' time, and caused only suffering. When I do that at my company, they do not call me "smart."
  - hhmc 8y ago
    Cleverness and morality can be orthogonal.
    - jmmcd 8y ago
      Bostrom's orthogonality thesis!
    - rexpop 8y ago
      Of course they can, but when I see an act of ingenious evil, my first response is not circumscribed admiration.
      - breakingcups 8y ago
        Concluding someone is smart doesn't always equal admiring them.
  - webmaven 8y ago
    If you do it to your company's competitor, you may qualify for a massive bonus (modulo your employer's moral compass and appetite for risk).
MrEldritch 8y ago
Thank you! I saw Ken Thomson's classic Reflections on Trusting Trust linked on HN a couple weeks ago, and was looking forward to rereading this very same story when I was surprised to discover it wasn't and had never been part of that essay at all. I had no idea where to find the actual story I'd been looking for! (Indeed, I was no longer sure this story had actually existed, and wasn't just something my brain had made up from cobbling together fragmentary memories) Thank you for solving this mystery. :)
stefs 8y ago
ah yes i remember this. a practical implementation of the http://wiki.c2.com/?TheKenThompsonHack http://wiki.c2.com/?TheKenThompsonHack ?
TheArcane 8y ago
> Because the compiler was poisoned with other source code that we didn't have. And that source code, that now existed only in the executable compiler, put those changes back into the compiler source before it compiled it. I don't quite understand this part. How would this work?
- antsar 8y ago
  If I read it correctly, they used the binary compiler which existed on the machine to compile a new copy of the compiler (from clean source). This existing binary compiler was "poisoned" (modified) such that it would not only poison the psychiatrist's program, but also poison any attempts to compile a new copy of the compiler. So when they recompiled the compiler, the new copy was already poisoned (because they used the old, poisoned compiler to do it).
- ChristianBundy 8y ago
  You need a compiler to compile anything, including a compiler, so if your compiler was tampered with then anything you compile can be tampered with as well. The only solution is be to download a binary compiler from someone you trust.
  - stefs 8y ago
    yes, but ken thompsons evil compiler theory states, that a trusted compiler is technically impossible (in the paranoid world of theoretical security where all compiler binaries are possibly tainted already) except if you write your own bootstrap compiler chain in machine code. still, all other running software (OS/drivers/the intel management engine) might be able to modify the binary in memory on the fly. the rabbit hole goes down to the hardware level.
    - emilfihlman 8y ago
      It doesn't even stop at hardware exactly (mcu/cpu), it only stops when you assemble the mcu/cpu yourself.
kuba-orlik 8y ago
Thank you, that's it!
tim333 8y ago
Some HN discussion on that (224 comments) https://news.ycombinator.com/item?id=10606226 https://news.ycombinator.com/item?id=10606226

https://www.quora.com/What-is-a-coders-worst-nightmare/answer/Mick-Stute https://www.quora.com/What-is-a-coders-worst-nightmare/answe...

by pliny 8y ago

https://www.quora.com/What-is-a-coders-worst-nightmare/answer/Mick-Stute https://www.quora.com/What-is-a-coders-worst-nightmare/answe...

deleted 8y ago

[deleted]

deleted 8y ago

[deleted]

pmichaud 8y ago

Jesus, that is intense. I wonder if the guy was personally out to get the Doc, or if he was just a smart kid with too much time and not enough superego?

kazinator 8y ago
He did make it super easy to find this by having the compiler modify source code. If you run "cc file.c" and file.c is overwritten, you should know that it's the "cc" doing it. It would have been more evil to do it the original way, as described in Thompson's paper: recognize the program sources and emit altered object code only; no mucking with the source.
rexpop 8y ago
Interesting that the first adjective you use was "smart" when, in any decent scope of consideration, he has actually wasted many hours of others' time, and caused only suffering. When I do that at my company, they do not call me "smart."
- hhmc 8y ago
  Cleverness and morality can be orthogonal.
  - jmmcd 8y ago
    Bostrom's orthogonality thesis!
  - rexpop 8y ago
    Of course they can, but when I see an act of ingenious evil, my first response is not circumscribed admiration.
    - breakingcups 8y ago
      Concluding someone is smart doesn't always equal admiring them.
- webmaven 8y ago
  If you do it to your company's competitor, you may qualify for a massive bonus (modulo your employer's moral compass and appetite for risk).

MrEldritch 8y ago

Thank you! I saw Ken Thomson's classic Reflections on Trusting Trust linked on HN a couple weeks ago, and was looking forward to rereading this very same story when I was surprised to discover it wasn't and had never been part of that essay at all. I had no idea where to find the actual story I'd been looking for! (Indeed, I was no longer sure this story had actually existed, and wasn't just something my brain had made up from cobbling together fragmentary memories) Thank you for solving this mystery. :)

stefs 8y ago

ah yes i remember this. a practical implementation of the http://wiki.c2.com/?TheKenThompsonHack http://wiki.c2.com/?TheKenThompsonHack ?

TheArcane 8y ago

> Because the compiler was poisoned with other source code that we didn't have. And that source code, that now existed only in the executable compiler, put those changes back into the compiler source before it compiled it. I don't quite understand this part. How would this work?

antsar 8y ago
If I read it correctly, they used the binary compiler which existed on the machine to compile a new copy of the compiler (from clean source). This existing binary compiler was "poisoned" (modified) such that it would not only poison the psychiatrist's program, but also poison any attempts to compile a new copy of the compiler. So when they recompiled the compiler, the new copy was already poisoned (because they used the old, poisoned compiler to do it).
ChristianBundy 8y ago
You need a compiler to compile anything, including a compiler, so if your compiler was tampered with then anything you compile can be tampered with as well. The only solution is be to download a binary compiler from someone you trust.
- stefs 8y ago
  yes, but ken thompsons evil compiler theory states, that a trusted compiler is technically impossible (in the paranoid world of theoretical security where all compiler binaries are possibly tainted already) except if you write your own bootstrap compiler chain in machine code. still, all other running software (OS/drivers/the intel management engine) might be able to modify the binary in memory on the fly. the rabbit hole goes down to the hardware level.
  - emilfihlman 8y ago
    It doesn't even stop at hardware exactly (mcu/cpu), it only stops when you assemble the mcu/cpu yourself.

kuba-orlik 8y ago

Thank you, that's it!

tim333 8y ago

Some HN discussion on that (224 comments) https://news.ycombinator.com/item?id=10606226 https://news.ycombinator.com/item?id=10606226