Is there a standard that defines what is a valid SSID and password?

Anand G picture Anand G · Feb 7, 2011 · Viewed 49.3k times · Source

We are developing a wireless n/w configuration UI and need to check if a SSID is a valid one? Are there any restrictions on the character set? length ? anything more..

Answer

Per Knytt picture Per Knytt · Feb 16, 2011

Section 7.3.2.1 of the 802.11-2007 specification (http://standards.ieee.org/getieee802/download/802.11-2007.pdf) defines SSIDs.

A valid SSID is 0-32 octets with arbitrary contents. A 0-length SSID indicates the wildcard SSID (in probe request frames for instance).

There's no character set associated with the SSID - a 32-byte string of NUL-bytes is a valid SSID.

This implies:

  • you should never use normal string functions when manipulating generic SSIDs (strcpy() and friends).

  • you should not assume that the SSID is printable when, for instance, logging it to disk