THM - Advent of Cyber 2022 - Day 19

Difficulty:
Challenge Link
OS: Linux

Learning Objectives How data is sent via electrical wires in low-level hardware Hardware communication protocols * How to analyze hardware communication protocols * Reading USART data from a logic capture

What device can be used to probe the signals being sent on electrical wires between two devices?

Answer

Logic Analyser

USART is faster than SPI for communication? (Yea,Nay)

Answer

Nay

USART communication uses fewer wires than SPI? (Yea,Nay)

Answer

Yea

USART is faster than I2C for communication? (Yea,Nay)

Answer

Nay

I2C uses more wires than SPI for communication? (Yea,Nay)

Answer

Nay

SPI is faster than I2C for communication? (Yea,Nay)

Answer

Yea

What is the maximum number of devices that can be connected on a single pair of I2C lines?

Answer

1008

What is the new baud rate that is negotiated between the microprocessor and ESP32 chip?

Use a logic analyzer tool called Saleae to analyze the logic data dump. Start the machine; the necessary tools are installed — Double-click the Logic 2 application to open the screen. Then, open the capture from your desktop. Look back in the module and play around with the different settings to find the baud rate. I struggled a little with this one.

Answer

9600

What is the flag that is transmitted once the new baud rate was accepted?

Answer

THM{Hacking.Hardware.Is.Fun}