Expiry bug (can convert v3 key to current?)

[disastry@saiknes.lv]

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Kurt Fitzner at Wed Jun 27 13:30:01 2001 wrote:
> 
> I've notived a bug, at least I think it's a bug, in gpg 1.06.  I imported an
> RSA key generated in PGP.  Upon editing the key, I tried to change the expiry
> date (trying to follow the FAQ directions for modifying the prefs), and was
> promptly told that I cannot modify the expiry date of a v3 key.  This is fine,
> but the expiry date does change if you do a 'list'.  It doesn't save when you
> quit, but, if before you quit do some other operation (add a UID for
> example) that would make the program ask you if you want to save, and you do
> save, then the new expiry date is saved in the key.
> 
> I'm not sure why expiry dates are not modifiable, unless it simply violates the
> protocol.

because for v3 keys expiry date is stored in key.
so changing it would make all signatures on that key invalid.

in v4 keys expiry date is stored in selfsignature,
so when changing expiry date, new selfsignature is made.

> My real question, though, is whether there any way to convert a v3 key to
> current?  I would like to import an RSA key, and also be able to set preferences
> and modify the expiry date.

well, even if you convert it will have different keyid and fingerprint
because for v4 keys keyid and fp are calculated differently

> Also, I was wondering why I can generate a 2048 bit signing DSA subkey, but
> can't make one as the primary key.

you cant, I just tried:

About to generate a new DSA keypair.
              minimum keysize is  768 bits
              default keysize is 1024 bits
    highest suggested keysize is 2048 bits
What keysize do you want? (1024) 2048
DSA only allows keysizes from 512 to 1024
What keysize do you want? (1024)

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