Module: PWN::SDR::Decoder::WiFi

Defined in:
lib/pwn/sdr/decoder/wifi.rb

Overview

802.11 (WiFi) beacon/probe decoder for the 2.4 / 5 / 6 GHz bands.

20+ MHz OFDM cannot be recovered from a general-purpose SDR at bit-level in real time, so this module drives an existing monitor-mode NIC via tshark (or airodump-ng) instead — freq_obj selects the interface, freq_obj is mapped to a WLAN channel.

Constant Summary collapse

TSHARK_FIELDS = 
%w[
  frame.time_relative
  wlan.fc.type_subtype
  wlan.bssid
  wlan.sa
  wlan.da
  wlan_radio.channel
  wlan_radio.signal_dbm
  wlan.ssid
].freeze

Class Method Summary collapse

Class Method Details

.authors ⇒ Object

Author(s)

0day Inc. support@0dayinc.com



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# File 'lib/pwn/sdr/decoder/wifi.rb', line 74

public_class_method def self.authors
  "AUTHOR(S):\n  0day Inc. <support@0dayinc.com>\n"
end

.decode(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::WiFi.decode( freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq' )



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# File 'lib/pwn/sdr/decoder/wifi.rb', line 31

public_class_method def self.decode(opts = {})
  freq_obj = opts[:freq_obj]
  raise 'ERROR: :freq_obj is required' unless freq_obj.is_a?(Hash)

  iface = (freq_obj[:mon_iface] || 'wlan0mon').to_s
  hz    = PWN::SDR.hz_to_i(freq: freq_obj[:freq])
  mhz   = (hz / 1_000_000.0).round

  tshark = ['tshark', '-i', iface, '-I', '-l', '-n',
            '-Y', 'wlan.fc.type == 0',
            '-T', 'fields', '-E', 'separator=|']
  TSHARK_FIELDS.each { |f| tshark.push('-e', f) }

  inner = "iw dev #{Shellwords.escape(iface)} set freq #{mhz} 2>/dev/null; " \
          "exec #{Shellwords.join(tshark)}"
  direct_cmd = "bash -c #{Shellwords.escape(inner)}"

  PWN::SDR::Decoder::Base.run_pipeline(
    freq_obj: freq_obj,
    protocol: 'WiFi-802.11',
    required_bins: %w[tshark iw],
    direct_cmd: direct_cmd,
    line_match: /\S/,
    parser: proc { |line| parse_line(line: line) }
  )
end

.help ⇒ Object

Display Usage for this Module



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# File 'lib/pwn/sdr/decoder/wifi.rb', line 80

public_class_method def self.help
  puts "USAGE:
    #{self}.decode(
      freq_obj: 'required - freq_obj returned from PWN::SDR::GQRX.init_freq'
    )

    NOTE: Requires a monitor-mode WLAN interface (freq_obj[:mon_iface],
          default 'wlan0mon'), `iw`, and `tshark`. General SDRs cannot
          demodulate 802.11 OFDM in real time.

    #{self}.parse_line(line: '0.1|8|aa:bb:..|aa:bb:..|ff:ff:..|6|-42|linksys')

    #{self}.authors
  "
end

.parse_line(opts = {}) ⇒ Object

Supported Method Parameters

PWN::SDR::Decoder::WiFi.parse_line(line: 't|subtype|bssid|sa|da|ch|rssi|ssid')



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# File 'lib/pwn/sdr/decoder/wifi.rb', line 61

public_class_method def self.parse_line(opts = {})
  f = opts[:line].to_s.split('|', -1)
  out = {
    protocol: 'WiFi',
    subtype: f[1], bssid: f[2], sa: f[3], da: f[4],
    channel: f[5], rssi_dbm: f[6], ssid: f[7]
  }.reject { |_, v| v.to_s.empty? }
  out[:summary] = "WiFi ch#{out[:channel]} #{out[:bssid]} '#{out[:ssid]}' #{out[:rssi_dbm]}dBm"
  out
end