Heavy lifting with McSema 2.0

blog.trailofbits.com

37 points·wglb··8 comments

One of the McSema contributors here.

McSema 2.0 has been a very big release for us with a complete re-architecture of how we do instruction semantics definitions and lifting. Aside from architectural improvements, it is also much faster than before!

Transpiling from x86-64 <-> AArch64 has been something we thought should be possible and we were very excited to get it working.

We're planning some more blog posts in the near future to talk about other McSema features and some use cases for x86 to LLVM translation.

Decompiler authors should take a look at the library, Remill, released with McSema 2.0. It lifts more of x86-64 than RetDec or fcd currently do.

I was peeking at McSema the other day. An idea I was tossing around in my head is whether I could have closed-source generic binaries run in WASM with it.

Edit: just saw I'm not the only one w/ the thought - https://twitter.com/dguido/status/497835951767695360

That's a neat idea. Does WASM provide support for calling OS functions? Or would you have to emulate them somehow?

Maybe its possible to forge something together with emscripten?

Emscripten emulates syscalls in a lot of ways. I think the LLVM standalone WASM (i.e. sans emscripten) expects those to be imported but I don't remember.

Is the name of this product a play on Macsyma[1]?

[1] https://en.wikipedia.org/wiki/Macsyma

No, it's closer to [m]achine [c]ode [sema]ntics.

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