How to detect fingerprint and type of the key from pubring.gpg(public keyring file)?

[David Shaw]

On Aug 1, 2013, at 6:58 PM, Martin T <m4rtntns at gmail.com> wrote:

> Hi,
> 
> RIPE(RIR in European region) database allows one to upload ASCII armored PGP public keys: http://www.ripe.net/data-tools/support/security/pgp Server-side software is able to generate some "key-cert" object attributes automatically. For example "method", "owner" and "fingerpr":
> 
> noc at T42 ~ $ whois -h whois.ripe.net -t key-cert | grep gene
> method:         [generated]  [single]     [ ]
> owner:          [generated]  [multiple]   [ ]
> fingerpr:       [generated]  [single]     [inverse key]
> noc at T42 ~ $ 
> 
> 
> Example "key-cert" object provided by RIPE:
> 
> key-cert: PGPKEY-4B8AE00D
> method:   PGP
> owner:    Joe User <joe at example.net>
> fingerpr: 9D 82 4B B8 38 56 AE 12  BD 88 73 F7 EF D3 7A 92
> certif:   ---BEGIN PGP PUBLIC KEY BLOCK---
> certif:   Version: 2.6.3ia
> certif:
> certif:   mQA9AzZizeQAAAEBgJsq2YfoInVOWlLxalmR14GlUzEd0WgrUH9iXjZ
> certif:   a/uqWiLnvN59S4rgDQAFEbQeSm9lIFRoZSBVc2VyIDxqb2VAZXhhbXB
> certif:   iQBFAwUQNmLN5ee83n1LiuANAQFOFQGAmowlUYtF+xnWBdMNDKBiOSy
> certif:   YvpKr05Aycn8Rb55E1onZL5KhNMYU/gd
> certif:   =nfno
> certif:   ---END PGP PUBLIC KEY BLOCK---
> mnt-by:   EXAMPLE-MNT
> changed:  joe at example.net 19981117
> source:   TEST
> 
> 
> How are those fields automatically detected/generated? "Owner"(UID in gpg terminology) is written to public key- one can verify this with analyzing the public key with hex editor. However:
> 
> 1) is "method" also built into public key? At least "hexdump -C pubring.gpg | grep -i pgp" does not indicate this.. Or has "PGP" some sort of special fingerprint which is understood by server-side software? Last but not least, are there any other types besides "PGP"? I guess it is as pgpdump is even able to dump the timestamp when the key itself was generated.

I think "method" in the example above is just indicating that this is a PGP key.  That is, there may be other types than PGP that RIPE supports, but you'd have to ask them about that.


> 2) is fingerprint automatically hashed based on the UID?

No.  The fingerprint is based on the key material only.  You can add/change UIDs without the fingerprint changing.

David