Inaccurate parsing of 802.11 element "RSN Information"

[giladbeeri]

I'm parsing an 802.11 frame that contains some tag elements, specifically, "RSN Information" (48).

"RSN Information" is parsed with a conditional field of PMKID, but I think the condition is not accurate, and in addition, there's another field afterwards called "Group Management Cipher Suite" (4 bytes).
https://github.com/secdev/scapy/blob/master/scapy/layers/dot11.py#L880

• Scapy version: latest (https://github.com/secdev/scapy.git@f2a111e6d4821c199a0cf5f42bc5bb5dcbe6ff04)
• Python version: 3.8.2
• Operating System: Ubuntu 16.04#### How to reproduce

Steps to Reproduce

python -c "from scapy.all import rdpcap; f = rdpcap('scapy.pcap'); p = f[0]; beacon = p.getlayer(5); print(beacon.network_stats()['ssid'])"

Actual result

(some garbage which is data from the packet)

���\xdd�P\xf2���\x81�\xa4'\xa4BT^a2/��\xdd\xa0\xc6���

Expected result

The real SSID: ROUTE-821E295

Related resources

The frame that reproduces the issue:

scapy.pcap.zip

Wireshark's parsing of the RSN Information element:

[guedou]

Closed by #2685

[giladbeeri]

@guedou I don't think this one should be closed. #2685 is a solution that resolves the issue of the improper SSID overriding, which is a result of this issue.
This issue, of the wrong RSN Information element parsing, is still relevant (it just won't create SSID overriding anymore, but the parsing is still wrong).