Jason An Aplet123

HackTM Writeups

I participated in HackTM with team DiceGang. Here are the writeups for the challenges that we solved.

Crypto

RSA is Easy #1

We are given a public key and an encrypted flag, which seems to be encrypted character by character. Using the provided public key we encrypt every possible character (0...255) and substitute each value in the encrypted flag with the corresponding character. Solve script:

Rev0

What does func("b4by_r3vers1ng_ch4ll") return?

func:
        push      rbp
        mov       rbp, rsp
        sub       rsp, 16
        mov       QWORD PTR [-16+rbp], rdi
        mov       rax, 0x0cafebabe
 mov QWORD PTR [-8+rbp], rax

GoogleCTF Sprint Writeup

Sprint faster than this binary!

Part 1: Starting Analysis

We're given a standard ELF, so we open it in Binary Ninja to try to figure out what it's doing:

(you may have to open the image in another tab and zoom in since it's small)

	9/1/2017
	===
	Initial commit - ACB
	Add files via upload - Aplet
	Add files via upload - Aplet
	Set first board to svg and put some adjustments - Aplet
	===
	9/2/2017
	===
	more attempts at blending the new board in - ACB

	use std::process::{Command, exit};
	use std::env;
	use std::collections::HashMap;
	use std::path::{Path, PathBuf};
	use std::fs;

	fn stop(msg: &str) -> ! {
	println!("Error: {}", msg);
	exit(1);
	}