My public key block appears different on keyservers

[David SMITH]

On Thu, Jul 02, 2009 at 08:36:14AM -0400, Matt Gantner wrote:
> I'm not terribly familiar PNG or GPG keys so bear with me.
> 
> I am understanding your statement to be saying that the two keys are
> really the same asci text but the line breaks make them appear to be
> different.
> 
> To test that I ran diff on the two keys and they are completely
> different text. Every line was different. So I am falling back to my
> theory that the key server software appears to make the public key
> different by the nature of its encoding when uploaded.

If you look at the two keys you posted, then the line lengths are
different.  However, they both contained the same text, The two
webservers just chose to break the lines at different places, and
I guess that the OpenPGP format allows the sender to vary the line
length when ASCII-armouring a key.

If you look at the two keys you posted, then the line
lengths are different.  However, they both contained
the same text.  The two keyservers just chose to break
the lines at different places, and I guess that the
OpenPGP format allows the sender to vary the line
length when ASCII-armouring a key.

^^^ See what I mean?

> I managed to set another computer up, with a second gpg identity. I
> encoded a message to my first identity using a public key from the
> gnupgp keyserver and was able to decrypt it successfully. So despite
> the variation in the asci text and length of the public key works.
> 
> I am still curious however and wonder if anyone has a theory why these
> public keys change depending on the key server?

Because the data "file" you download from the keyserver is not just a
binary copy of the key - the key can be encoded in different ways, and
there could also be other information encoded in there.

For example: consider a file compressed with "gzip".  gzip allows the
user to specify the compression ratio required from -1 to -9 - the
larger the number, the better compression ratio that it achieves, but
the longer it takes to run.

If you look at each of the compressed files individually, they will
all look completely different (since they have been compressed in
subtly different ways), but if you uncompress each of them with
gunzip, they all end up producing the same result - the file which
was originally compressed.

The bottom line: Yes, the key arriving from the keyserver might not
look the same in its ASCII-armoured form.  Unless you see a problem
with the key once it's been imported into GPG, don't worry about it.

-- 
David Smith        | Tel: +44 (0)1454 462380    Home: +44 (0)1454 616963
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