Ensure unique tags in signature header

[pmatilai]

Currently a bunch of signature tags overlap with the ones in the main header, requiring translation and making eg type checking harder than it should be. These overlaps need to be eliminated and made illegal in v6.

• RPMSIGTAG_PGP, RPMSIGTAG_GPG (and RPMSIGTAG_PGP5) are no longer created in >= 4.16
• RPMSIGTAG_MD5 is superceded by payload digest in >= 4.14, just needs to be dropped entirely
• RPMSIGTAG_SIZE and RPMSIGTAG_PAYLOADSIZE will go away with Default to 64bit size tags in headers #864
• RPMSIGTAG_RESERVEDSPACE is the only thing left. This needs to be rethought, perhaps borrow an idea from rpm5 where the signature header padding was added as a dribble to the header itself, this padding could also serve the same "reserved space" purpose.
• RPMSIGTAG_FILESIGNATURES and RPMSIGTAG_FILESIGNATURELENGTH is a different kind of mess, needs to be sorted out nevertheless (make RPMTAG_FILESIGNATURES just an alias for RPMSIGTAG_FILESIGNATURES or something)

[pmatilai]

(deleted irrelevant discussion)

[dralley]

RPMSIGTAG_FILESIGNATURES and RPMSIGTAG_FILESIGNATURELENGTH is a different kind of mess, needs to be sorted out nevertheless (make RPMTAG_FILESIGNATURES just an alias for RPMSIGTAG_FILESIGNATURES or something)

I noticed that (most? all?) Fedora 37 packages seem to have RPMTAG_FILESIGNATURES in the signature header (Instead of RPMSIGTAG_FILESIGNATURES), is this part of the mess you're referring to?

(The tag values are not overlapping, RPMTAG_FILESIGNATURES = 5090, RPMSIGTAG_FILESIGNATURES = 274, in this case 5090 is present in the signature header)

I cannot seem to find any reference to that as being a bug or even a relevant commit though. It must have been fixed at some point because Fedora 38 packages don't seem to have this issue. Or maybe the build pipeline changed?

[dralley]

I still haven't been able to track down a cause for ^, do you happen to remember anything?

[pmatilai]

The tag conflicts between signature and header are gone as of #3017, what remains is to error out if tags >= 1000 are found in v6 signature header.