Re: [PATCH 3/4] module: search the key only by keyid

From: Dmitry Kasatkin
Date: Fri Oct 03 2014 - 10:00:15 EST


On 03/10/14 16:40, David Howells wrote:
> Dmitry Kasatkin <d.kasatkin@xxxxxxxxxxx> wrote:
>
>> BTW. But actually why signer is needed to find the key?
>> Every key has unique fingerprint.
> The SKID is by no means guaranteed unique, is not mandatory and has no defined
> algorithm for generating it.

SKID is unique. SKID == SHA1(PK)

I understand that it may be missing for someone. But if it presents in
the certificate it should not be a problem...

>> Or you say that different certificates might have the same PK?
>> What I would consider strange. But anyway, if PK is the same, then
>> verification succeed.
> Do note: We *do* need to get away from using SKIDs. We have situations where
> we have to use a key that doesn't have one.
>
> David

I understand that... What I claim is that if there is a SKID, it is
unique and enough to identify certificate in the keyring...

Integrity subsystem uses partial SKID and it MUST NOT be broken for
compatibility.


Dmitry


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