Get expiration date by searching on keyservers

[Kristian Fiskerstrand]

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On 04/30/2014 07:25 PM, David Shaw wrote:
> On Apr 29, 2014, at 6:40 PM, Koen <koen.vanimpe at cudeso.be> wrote:
> 
>> Hi,
>> 
>> I use '--keyserver <srv> --search-keys <key'> to get info on a 
>> number of keys. As far as I can tell, that doesn't return an 
>> expiration date (if that exists).
> 
> GPG's keyserver code is capable of displaying expiration date, if
> the keyserver provides it.  Not all do.

To detail a bit more; we had a fix to read expiration from UID
self-signatures that is in the current trunk[0]. Earlier versions
(including 1.1.4) won't output these properly for the machine readable
index. For servers that does support it it can be seen as e.g.
http://sks.mrball.net:11371/pks/lookup?op=index&options=mr&search=0x0B7F8B60E3EDFAE3
that displays

pub:94CBAFDD30345109561835AA0B7F8B60E3EDFAE3:1:4096:1197735934:1483182002:

date -d at 1483182002
Sat Dec 31 12:00:02 CET 2016


> 
> But - and this is important - like all key data (from expiration 
> date, to revocation status, to the user IDs, etc), the info
> returned by a keyserver is only informational.  You cannot rely on
> it until you download the key and check it yourself.  The
> keyservers are simply storage, and do not verify the keys sent to
> them (and you shouldn't trust them even if they claimed to).
> 

Very much so, no verification on the validity of the self-signature or
other information is performed on the servers.


References:
[0]
https://bitbucket.org/skskeyserver/sks-keyserver/pull-request/12/fixes-for-machine-readable-indexes/diff

- -- 
- ----------------------------
Kristian Fiskerstrand
Blog: http://blog.sumptuouscapital.com
Twitter: @krifisk
- ----------------------------
Public PGP key 0xE3EDFAE3 at hkp://pool.sks-keyservers.net
fpr:94CB AFDD 3034 5109 5618 35AA 0B7F 8B60 E3ED FAE3
- ----------------------------
Veni vidi visa
I came, I saw, I bought
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