Book Review: Designing Secure Software

Designing Secure Software (Amazon, No Starch Press) by Loren Kohnfelder is one of the latest entries in No Starch Press’s line of security books. This book stands out to me for two big reasons. First, this is one of the most mindset-centric books I’ve seen (which means it is likely to age better than a lot of more technically-specific books). Second, this book caters to developers more than security professionals (but don’t take this to mean it’s only for developers), which is definitely a distinguishing feature from so many other security books.


Book Review: Bug Bounty Bootcamp

Bug Bounty Bootcamp (Amazon, No Starch Press) by Vickie Li is one of No Starch Press’s newest offerings in the security space. The alliterative title is also the best three word summary I could possibly offer of the book – it is clearly focused on getting the reader into a position to participate in Bug Bounties from the first page to the last. This differentiates this book well against other web security books, despite covering many of the same vulnerabilities.


0x0G CTF: gRoulette (Author Writeup)

0x0G is Google’s annual “Hacker Summer Camp” event. Normally this would be in Las Vegas during the week of DEF CON and Black Hat, but well, pandemic rules apply. I’m one of the organizers for the CTF we run during the event, and I thought I’d write up solutions to some of my challenges here.

gRoulette is a simplified Roulette game online. Win enough and you’ll get the flag. The source code is provided, and the entire thing is run over a WebSocket connection to the server.

gRoulette


0x0G CTF: Authme (Author Writeup)

0x0G is Google’s annual “Hacker Summer Camp” event. Normally this would be in Las Vegas during the week of DEF CON and Black Hat, but well, pandemic rules apply. I’m one of the organizers for the CTF we run during the event, and I thought I’d write up solutions to some of my challenges here.

The first such challenge is authme, a web/crypto challenge. The description just wants to know if you can auth as admin and directs you to a website. On the website, we find a link to the source code, to an RSA public key, and a login form.


GPU Accelerated Password Cracking in the Cloud: Speed and Cost-Effectiveness

Note: Though this testing was done on Google Cloud and I work at Google, this work and blog post represent my personal work and do not represent the views of my employer.

As a red teamer and security researcher, I occasionally find the need to crack some hashed passwords. It used to be that John the Ripper was the go-to tool for the job. With the advent of GPGPU technologies like CUDA and OpenCL, hashcat quickly eclipsed John for pure speed. Unfortunately, graphics cards are a bit hard to come by in 2021. I decided to take a look at the options for running hashcat on Google Cloud.