Going the other way with padding oracles: Encrypting arbitrary data!

A long time ago, I wrote a couple blogs that went into a lot of detail on how to use padding oracle vulnerabilities to decrypt an encrypted string of data. It's pretty important to understand to use a padding oracle vulnerability for decryption before reading this, so I'd suggest going there for a refresher. When […]

GitS 2015: knockers.py (hash extension vulnerability)

As many of you know, last weekend was Ghost in the Shellcode 2015! There were plenty of fun challenges, and as always I had a great time competing! This will be my first of four writeups, and will be pretty simple (since it simply required me to use a tool that already exists (and that […]

A padding oracle example

Early last week, I posted a blog about padding oracle attacks. I explained them in detail, as simply as I could (without making diagrams, I suck at diagrams). I asked on Reddit about how I could make it easier to understand, and JoseJimeniz suggested working through an example. I thought that was a neat idea, […]

Padding oracle attacks: in depth

This post is about padding oracle vulnerabilities and the tool for attacking them - "Poracle" I'm officially releasing right now. You can grab the Poracle tool on Github! At my previous job — Tenable Network Security — one of the first tasks I ever had was to write a vulnerability check for MS10-070 — a […]

Everything you need to know about hash length extension attacks

You can grab the hash_extender tool on Github! (Administrative note: I'm no longer at Tenable! I left on good terms, and now I'm a consultant at Leviathan Security Group. Feel free to contact me if you need more information!) Awhile back, my friend @mogigoma and I were doing a capture-the-flag contest at https://stripe-ctf.com. One of […]