:: [DNG] CLI backend: (E)SSID issues
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Συντάκτης: tilt!
Ημερομηνία:  
Προς: dng
Αντικείμενο: [DNG] CLI backend: (E)SSID issues
Hello,

it has come to my attention that an SSID is defined by a
(closed) IEEE standard as (I quote inofficial source [1]):

> [...] "0-32 octets with arbitrary contents. A 0-length
> SSID indicates the wildcard SSID (in probe request
> frames for instance)"


This means that

#1 SSIDs can have length zero.
#2 SSIDs can contain the zerobyte.

In the context of the CLI Back-En's (E)SSID encoder, this has
the following consequences:

a) I refuse to support case #1. It is a special case that
    to the extent of my knowledge only has use in special
    purpose frames exchanged in procedures of broadcasting
    or ad-hoc networking.


    If someone shows me otherwise, I will reconsider;
    it's of course not impossible to support it, just
    additional effort.


b) I am currently unable to support case #2, because the
    frontend does not pass the information "length of the
    SSID" to the backend. Instead it passes ans an entry
    of argv[] a C-type string which is a sequence of nonzero
    bytes terminated by a zerobyte. Thus, the backend is not
    capable of receiveing an SSID completely that contains
    the zerobyte, and furthermore, the backend had no way of
    determining the actual length of the SSID in bytes.


Ceterum censeo standards should be open.

Kind regards,
T.

Links:

[1]: stackoverflow.com. "Is there a standard that defines what is
a valid SSID and password?". Answer #1.
URL: http://stackoverflow.com/a/5017144