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Re: Reducing AES tables spaces

On Nov 18, 2008, at 2:05 PM, Arnaud Lacombe wrote:

Hi Folks,

I've got this patch for quite a time in my tree, I think some might find
this interesting.

We currently use in `sys/crypto/rijndael' an AES implementation which
use 10 huges static tables (in fact, 4 + 4 + 2). They are intended to
fasten the implementation. Each table entry is a circular permutation of
the same-index entry of another table. The comment on top of explain
this better:

Here's my AES implementation. It's small (5K of code and rodata on i386)
and quick.  I've been meaning to replace sys/crypto/rijndael with it.
I consider the existing code to be most writeonly code and wanted to
write an implementation I could understand.

Instead of hand tweaking things, I let the compiler decide what to do.
The heart of the algorithm is only 143 lines and half of that is comments.

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