---
title: 'Homework Assignments'
tags: enee459b-fall23
---

## Homework 1. Access
The `access` executable provided in this HW is a piece of software used for granting access to a turnstile. It provides simple user authentication using standard username/password combinations. Unfortunately, the company that developed the software inserted a backdoor to allow unfettered access to all the organizations that use the physical access control system.

* [Download the `access` and `passwd` binary](https://yonghwi-kwon.github.io/class/enee459b/data/access.zip)
* Obtain the binary in the class VM server

        $ mkdir hw1
        $ cd hw1
        $ cp /class/re-hw1/* ./

* [Full Homework Description](https://yonghwi-kwon.github.io/class/enee459b/data/HW1.pdf)
* [**Expected Answer Format/Content (Edited Oct 21)**](https://hackmd.io/@yonghwikwon/Sk3jfPez6)

## Homework 2. Data Structures
You have been provided a simple utility (`re-hw2`) that was written by a past co-worker, but nobody is quite sure what it does! It seems to be saving a binary file.
What is it doing, and what format is the binary file in?

* [Download the `re-hw2` binary](https://yonghwi-kwon.github.io/class/enee459b/data/re-hw2)
* Obtain the binary in the class VM server

        $ mkdir hw2
        $ cd hw2
        $ cp /class/re-hw2/* ./

* [Full Homework Description](https://yonghwi-kwon.github.io/class/enee459b/data/HW2.pdf)

## Take home activity: bomb64
The binary is a software bomb that if you could not provide the correct secret input, it will explode. Specifically, the binary has 6 phases where each phase expects a secret input. There is also a secret phase (hence total 7 phases). Can you figure all the expected inputs?
* [Download the `bomb64` binary](https://yonghwi-kwon.github.io/class/enee459b/data/bomb64)
* Obtain the binary in the class VM server

        $ mkdir bomb64
        $ cd bomb64
        $ cp /class/decompiler/bomb64 bomb64

* [Extra Credit Assignments](https://hackmd.io/@yonghwikwon/SJf9uAWfa)