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

[Mimi Zohar <zohar@linux.ibm.com>]

On Mon, 2019-06-17 at 17:42 +0300, Vitaly Chikunov wrote:

> > 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.

Perhaps it causes more patch churn, but there always is a way.  In
this case, there are a couple of ways.  Instead of replacing "key"
with "pkey":

- define pkey as an additional argument to calc_keyid_v2().
- define a new function named, for example, calc_keyid_v2_pkey().

Mimi