Re:Typing the Letters A-E-S Into Your Code (2009)
by tptacek on Saturday January 10, 2015 @10:06AM
(#8866882)
I'm flattered by the attention, as always.
Couple quick things:
On our original blog (I have nothing to do with this one; I haven't been at Matasano for several months), this was CSS-formatted to look like an actual script, which I think makes it significantly easier to follow. Dave Wagner copied it to his website, and it's closer to the original:
Second: in case you're impatient (I would be), conceptually, this is what the post is trying to communicate:
* Unauthenticated CBC is surprisingly malleable. There are two attacks in here that I thought were "clever": using totally random CBC block garbling strategically to eat quote characters and synthesize SQL injection (the motivating example for the post, after I pulled this attack off on a real system) and "stuffing" inputs with known plaintext to make rewriting easier.
* CBC padding oracles. I would be interested if anyone knows a source outside of academic literature that walked through this attack published prior to 2009.
It is not about how to implement single sign-on cookies.
The nice thing about posts about cryptographic attacks, as opposed to cryptographic constructions, is that they age pretty well. :)
Couple quick things:
On our original blog (I have nothing to do with this one; I haven't been at Matasano for several months), this was CSS-formatted to look like an actual script, which I think makes it significantly easier to follow. Dave Wagner copied it to his website, and it's closer to the original:
http://www.cs.berkeley.edu/~daw/teaching/cs261-f12/misc/if.h...
Second: in case you're impatient (I would be), conceptually, this is what the post is trying to communicate:
* Unauthenticated CBC is surprisingly malleable. There are two attacks in here that I thought were "clever": using totally random CBC block garbling strategically to eat quote characters and synthesize SQL injection (the motivating example for the post, after I pulled this attack off on a real system) and "stuffing" inputs with known plaintext to make rewriting easier.
* CBC padding oracles. I would be interested if anyone knows a source outside of academic literature that walked through this attack published prior to 2009.
It is not about how to implement single sign-on cookies.
The nice thing about posts about cryptographic attacks, as opposed to cryptographic constructions, is that they age pretty well. :)