Text 11266, 45 rader
Skriven 2019-08-18 17:37:31 av Rob Swindell (30284.ftsc_pub)
Ärende: Max subject length: 71 or 72 chars?
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Synchronet and SBBSecho has always treated the to, from, and subject fields in
FidoNet "Stored Messages" (*.msg files) and "Packed Messages" (those contained
in type 2 packets) as null-terminated strings with a maximum *usable* length of
35 characters for the "to" and "from" and a maximum *usable* length of 71
characters for the "subject".

However, in reviewing FTS-1 (http://ftsc.org/docs/fts-0001.016) my/our
interpretatoin may be wrong.

FTS-1 is ambiguous about whether or not the last character of these fields may
be used or not. In other words, if a "to" or "from" name is exactly 36
characters, is it legal to use all 36 characters and *not* include a null
terminator in a stored message? It is a fixed-length field after-all, so a
terminator should not be needed if all 36 characters are used. Similarly, would
it be possible to use all 72 characters for a message subject? This would be
consistent with how the "password" field in a packet header is stored (no null
terminator included for full-length passwords).

"Packed Messages" use variable length header fields, so even full-length header
fields (e.g. a 36-character to or from name) would still require a null
terminator. But the spec is not clear:

              |                    subject                    |
              ~                  max 72 bytes                 ~
              |                null terminated                |

It's not clear if that "null" is *included* in the max 72 bytes, or not. :-(

How does *your* implementation handle these fields? What would happen if you
received a Stored Message where byte 71 (the 72nd byte) of the "subject" was
non-null? Or if you received a packet that included a 72-character subject
followed by a null? Both of these conditions do not appear to violate FTS-1,
but I'm not sure how other programmers have interpetted these specs over the
years.

It seems wasteful to have critical bytes in a packet header that are *always*
zero, so if we could agree that byte 71 (couting from 0) of a subject and byte
35 (again, counting from 0) of to/from names are *usable*, that would make
these message/packet formats a little more sane.

But in any case, the spec (FTS-1) needs clarification: I can easily justify
either interpration, which could lead to wildly-incompatible implementations of
FTN message/packet generating and parsing software.
--- SBBSecho 3.08-Linux
 * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)