Re: [PATCH 0/4] Switch remaining algorithms to shash

Hello Herbert,

Herbert Xu wrote:

On Thu, Dec 04, 2008 at 01:18:08AM +0100, Adrian-Ken Rueegsegger wrote:

quoted

The first patch removes the message schedule W from struct sha512_ctx
since it gets calculated anew on each execution of sha512_transform. This
reduces the size of sha512_ctx considerably and will allow it to be
registered as a shash algorithm (it will pass the size check in
crypto_register_shash (crypto/shash.c:490)).
Herbert, could you explain why descsize must be smaller (or equal)
than PAGE_SIZE / 8?

This is so that people can put it on the stack safely.  So moving
things out of the context and onto the stack because it's too big
is a no-no :)

Thanks for the explanation.

Perhaps store in a static percpu area?

quoted

The next two patches switch sha512 and wp512 to the new shash interface.

BTW, in order to add missing Kconfig dependencies on HASH I've
just rebased my tree and updated all the shash conversion patches.
So please resend them with the Kconfig bits added.

Will do. I will resubmit the patches later today.

quoted

The fourth patch is another try to convert michael_mic. The key values
l and r are duplicated in the descriptor part since they are used and
changed during the actual transformation. I would be gratefull for
comments on this patch since I am not sure it's the proper way to do it.

Since they're read-only they should be obtained from the tfm context
when needed, just like crc32c.

If I read the code correctly l and r are not read-only, e.g. in
michael_update there are multiple assignments to mctx->l and mctx->r.
That's the reason why I left them in the desc context.

Thank you for your comments,
Adrian