Subject: [Tzdist-bis] Fwd: Fwd: helpppppp: draft-murchison-tzdist-tizf-05

From: Eliot Lear <[email-masked]>
Date: Sun, 1 Jul 2018 16:36:56 +0200

This should have gone to this mailing list.  My apologies.  This is now
dated.

Eliot

Subject: Fwd: helpppppp: draft-murchison-tzdist-tizf-05
From: Eliot Lear <[email-masked]>
To: Ken Murchison <[email-masked]>, Arthur Olson <[email-masked]>, Paul Eggert <[email-masked]>
Date: Thu, 7 Jun 2018 15:38:32 -0400

FYI

Subject: Re: helpppppp: draft-murchison-tzdist-tizf-05
From: Ned Freed <[email-masked]>
To: Eliot Lear <[email-masked]>
Cc: Ned Freed <[email-masked]>
Date: Thu, 07 Jun 2018 08:52:24 -0700 (PDT)

> Ned,

> Could I prevail upon you for a review of this document wrt the MIME
> media type registration (or any other comment you might have)?  It's a
> pretty cool doc.  Arthur David Olson, Ken Murchison, and Paul Eggert
> have finally broken down and documented the binary TZ file format in a
> draft.  It's way geeky cool after all of these years.

> Anyway, someone needs to stare at the registration to make sure it looks
> ok.  Want to be that someone?

Sure, no problem. The registration as it stands has a couple of issues.
First, I'd recommend changing the N/As to none for the required and
optional parameters, like so:

   Required parameters:  none

   Optional parameters:  none

Second, the security considerations need to be filled in. How about something
like:

     tzif contains no executable code and the format does not define
     any extensibility areas that could be used to store such code.

     The tzif format contains counted arrays of data elements. All counts
     should be checked when processing tzif objects to guard against
     references past the end of the object.

     tzif provides no confidentiality or integrity protection. Time zone
     information is normally public and does not call for condidentiality
     protection. Since time zone information is used in many critical
     applications integrity protection may be required, and must be
     provided externally.
    
Some additional wordsmithing is probably in order, but this is a start.

Finally, the application section currently says:

   Applications that use this media type:  This media type is designed
      for widespread use by applications that need to exchange time zone
      information.  The Time Zone Distribution Service [RFC7808] can
      directly use this media type.

Not required, but I think it would be a good idea to list some of the
actual utilities that handle this format. Maybe not here, but somewhere.

That's it!

				Ned

P.S. FYA, here's a section of Pascal code I wrote many many moons ago:

          start :: integer_address := start :: integer_address + 32;
          timecnt := 0;
          FOR j := 1 TO 4 DO BEGIN
            timecnt := lshift (timecnt, 8) + ord (start^);
            start :: integer_address := start :: integer_address + 1;
            END; (* for *)
          IF debug THEN
            debug_write_formatted_list ('  Count of transition times = %d.',
                                        timecnt);
          typecnt := 0;
          FOR j := 1 TO 4 DO BEGIN
            typecnt := lshift (typecnt, 8) + ord (start^);
            start :: integer_address := start :: integer_address + 1;
            END; (* for *)
          IF debug THEN
            debug_write_formatted_list ('  Count of local time values = %d.',
                                        typecnt);
          charcnt := 0;
          FOR j := 1 TO 4 DO BEGIN
            charcnt := lshift (charcnt, 8) + ord (start^);
            start :: integer_address := start :: integer_address + 1;
            END; (* for *)
          IF debug THEN
            debug_write_formatted_list ('  Count of abbreviation values = %d.',
                                        charcnt);

Look familiar?

				Ned