The other day I had a wireless network packet capture file saved as a .cap file. The ESSID that was displaying via normal aircrack-ng output of the WPA/WPA2 wireless packet capture lead me to believe there was at least one space included in the beginning of the ESSID and likely after the ESSID since it was not processing properly using oclHashcat-plus. I had never run into this before so wasn’t exactly sure the easiest way to figure out the number of spaces so I posed the question in the Freenode aircrack-ng IRC channel and got a couple responses which are noted below as well as instructions following the clearest solution.
A while ago I wrote a short tutorial on how to strip down a wireless capture which contained a wpa handshake so that only eapol packets and beacon frames where left. I have since found a little bit better way to do it so I decided to make a new post. In the previous article I showed how to strip by wlan.mgt frames containing the mac address. The problem with this is that it strips out lots of other packets which some programs use to check for ESSID. I looked into the issue some more and found a way to strip just by essid.