Nebula Walkthrough

Nebula is a virtual machine from Exploit Exercises that goes through basic local Linux exploitation. Quoting from the website, Nebula takes the participant through a variety of common (and less than common) weaknesses and vulnerabilities in Linux. It takes a look at SUID files …
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A DNSSEC Primer

DNSSEC is a hugely complex protocol. The current specification is defined in three RFCs: RFC4033, RFC4034 and RFC4035. This post will attempt to explain the core of the protocol and what is required to sign a DNS zone with DNSSEC. The process of validating DNSSEC records shall be…
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An interesting crypto vulnerability

I came across an interesting tweet by Juliano Rizzo. The correct answer is that the statement is true if several (very unlikely to happen in the real world) conditions are met. Let us take a look at why it happens and what conditions have to be met for this to work. 1. HMAC I …
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A faster PBKDF2 for Python

I came across a blog post titled "PBKDF2: performance matters" where the author discusses how most implementations of PBKDF2 are slower than it otherwise could be. After reading the blog post, I decided to write some Python bindings to see how much of a performance incr…
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Introducing python-aead

Cryptography libraries often have complicated APIs with many different options to tweak. It is a goal PyCA's cryptography library to provide safe and easy to use APIs for common cryptographic tasks. To that end, the cryptography package has a Fernet recipe for symmetric encryptio…
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