picoCTF2019 Reverse Engineering Asm

Hello, here’s my take on the picoCTF2019 reverse engineering asm challenges. If you don’t know assembly, please watch a few tutorials on it: asm1 – Points: 200 CMP: Compares the first source operand with the second source operand and sets the status flags in the EFLAGS register according to the results. The comparison is performed by subtracting the second operand from the first operand and then setting the status flags in the same manner as the SUB instruction. When an immediate value is used as an operand, it is sign-extended to the length of the first operand. ...

February 23, 2020 · 3 min · Denis Nuțiu

Introduction to GCC’s Extended ASM Format

As I’ve been reading Professional Assembly Language, I’ve come across chapter 13 and I liked it so much that I’m going to write a blog post about it. The book is quite nice if you’re interested in assembly for Linux. Extended ASM format let’s you write assembly code that interacts with any type of C data, such as local variables, strings, numbers, goto labels and so on. The format produces cleaner, safer and more efficient code than the Basic ASM format. ...

July 27, 2018 · 4 min · Denis Nuțiu