Re: [PATCH v4 4/5] ima-evm-utils: Convert sign v2 from RSA to EVP_PKEY API

[Vitaly Chikunov <vt@altlinux.org>]

Mimi,

On Mon, Jun 17, 2019 at 09:34:46AM -0400, Mimi Zohar wrote:
> On Fri, 2019-06-14 at 04:54 +0300, Vitaly Chikunov wrote:
> > Convert sign_v2 and related to using more generic EVP_PKEY API instead
> > of RSA API. This enables more signatures to work out of the box.
> 
> Please elaborate on "enables more signatures to work out of the box",
> perhaps with example(s).

Yes, message is split between next commit where it's mentioned that MD4
got fixed. I will also mention EC-RDSA. Basically, anything that OpenSSL
supports will work.

> I like simple stories, where everything is laid out.  Think of a patch
> set as a simple story, not a mystery, explaining how you go from point
> A to point B.  Each patch in the series explains the next step.
> 
> The changes in cmd_import() are nice, straight forward, and easy to
> read.  Other than the "calc_keyid_v2()" change from passing an RSA key
> to pkey key" dependency, this could be a separate patch.
> Please see if you could further break this patch up to simplify review.

I thought about splitting as much as possible, but didn't not find what
to split more.

- If we add read_pub_pkey into cmd_import then we can not use old
calc_keyid_v2 (which wants RSA).
- If we add new calc_keyid_v2 into cmd_import it would require calling
read_pub_pkey (and have sign_hash_v2 updated too).
- We can not put cmd_import change before 'rsa to pkey' change, because
calc_keyid_v2 is also used in new sign_hash_v2.
- We can not put cmd_import change after 'rsa to pkey' change, because
cmd_import will fail for v2 signatures (which should use PKEY).

So I don't see how this is splittable.

Thanks,