Artisanal RSA

Sometimes hacking requires doing things that, while possible to do with some algorithm, simply aren’t supported by any existing implementation. Usually for good reason. A good example of this that I’ve run into in the past is needing to initialize a hash algorithm with a specific state. There’s really not any reason to do this unless you’re trying to execute a length extension attack, and with the exception of HashPump (which was written specifically for that use case) I’m not aware of any library that supports it. I recently ran into this with problem with RSA.

Read more...

HTTPS Subresource Validation Fail

In the spring of 2014, I found a bug in several browsers, including Epiphany, Xombrero, Opera Mini and Midori. They were loading subresources, such as scripts, from HTTPS servers without doing proper certificate validation. I tracked this down to some bad defaults in webkit which have since beenfixed.

Read more...

Stupid Certificate Tricks

Sometimes I do things for no real reasons other than “because I can” and/or “it amuses me”. For example, embedding a snarky message into my HTTPS certificate.

Read more...