Keys clean of all signatures except those made by others I trust

[FuzzyDrawrings]

On January 24, 2018 11:58 PM, Werner Koch <wk at gnupg.org> wrote:

>On Tue, 23 Jan 2018 08:41, gnupg-users at gnupg.org said:
>
>>I would like to clean the key of the spam signatures while preserving
>> any signatures made by Alice (or anyone else I have trusted on my
>> keyring). Does there exist a command/option to accomplish this in
>> gpg2?
>>
> I do blacklisting of certain signatures in my gpg.conf.  A blacklist may
> look like this
>
> import-filter drop-sig=   sig_created_d=2015-12-24
> import-filter drop-sig=|| sig_created_d=2016-03-16
>
> and a whitelist would be
>
> import-filter drop-sig=   sig_created_d<>2015-12-24
>import-filter drop-sig=&& sig_created_d<>2016-03-16
>
> Unfortuntely a property for comparing the key-id or the fingerprint is
> not yet available.  Shall I look into this?

I was able to get the results I needed by using the 'clean' command under --edit-key, and also '--import-options import-clean'.

'import-filter' option is unavailable to me as I use the GnuPG versions in Ubuntu repository. If I put either the blacklist or whitelist in gpg.conf, GPG 2.1.11 hangs while GPG 1.4.20 declares it an 'invalid option'