Discrepancies in extracted photo-id images from dumps

[Stefan Claas]

On Sun, 20 Jan 2019 17:07:23 +0100, Peter Lebbing wrote:
> On 20/01/2019 16:05, Stefan Claas wrote:
> > Thanks, but it is still unclear to me what content of the user id
> > is taken. Here for example an old key from me:  
> 
> I had a quick scan through the source code, but couldn't find it. But it
> seems to me it's likely to be a hash of the User Attribute Packet (RFC
> 4880), which is an alternative form of a User ID. As such, it would be a
> unique identifier of the image in question. Does it really matter?

Ah, o.k. Well, matter ... i only want to understand how this base32
data is created. :-)
 
> > If i base32 decode the strings i get binary output which i don't
> > understand.  
> 
> It's 32 digits of base32, which makes it 32*2log(32) = 32*5 = 160 bits.
> So my guess is it's a raw hash and as such not something to be
> "understood" but high entropy data. Either a 160-bit hash (seems likely)
> or a truncated longer hash.

Thanks, that makes then sense.

> Oh, note that the base32 is the one from RFC 6189, not the one from
> 3548. I saw that in the source. I played around a bit, but couldn't
> quickly home in on what the hash actually is. Maybe you have better
> luck (or more patience :-). Hashes are rather unforgiving of mistakes
> you make in the input to it :-).

O.k., i will takes a closer look and if i figured out the proper procedure
i will post my findings.

Regards
Stefan