edibledinos/pwnypack

Certified Edible Dinosaurs official CTF toolkit

pwnypack's Issues

python assembler: jrel off by one?

I tried assembling Python 2.7 code. It worked on basic stuff but started to fail when things got slightly more complicated. I dug a little into it, and I think the problem is in bytecode.py, in handling of jrel operations (I think all of them), that offset 0 is taken to mean "the last byte of the jump instruction", but really offset 0 should mean "the byte AFTER the last byte of the jump instruction, i.e. the first byte of the next instruction", so it's off by one byte. I wasn't sure enough to fix it on my own but when I added it it did seem to work.