New Credit Card sniffer.

lib/bettercap/sniffer/parsers/creditcard.rb

@@ -0,0 +1,62 @@
+=begin
+
+BETTERCAP
+
+Author : Simone 'evilsocket' Margaritelli
+Email  : [email protected]
+Blog   : http://www.evilsocket.net/
+
+This project is released under the GPL 3 license.
+
+=end
+
+module BetterCap
+module Parsers
+# CC parser.
+class CreditCard < Base
+  PARSERS = [
+    # All major cards.
+    /(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6011[0-9]{12}|3(?:0[0-5]|[68][0-9])[0-9]{11}|3[47][0-9]{13})/m,
+    # American Express
+    /(3[47][0-9]{13})/m,
+    # Diners Club
+    /(3(?:0[0-5]|[68][0-9])[0-9]{11})/m,
+    # Discover
+    /(6011[0-9]{12})/m,
+    # MasterCard
+    /(5[1-5][0-9]{14})/m,
+    # Visa
+    /(4[0-9]{12}(?:[0-9]{3})?)/m
+  ].freeze
+
+  def on_packet( pkt )
+    begin
+      payload = pkt.to_s
+      PARSERS.each do |expr|
+        matches = payload.scan( expr )
+        matches.each do |m|
+          StreamLogger.log_raw( pkt, 'CREDITCARD', m ) if luhn?(m)
+        end
+        break unless matches.empty?
+      end
+    rescue; end
+  end
+
+  # Validate +cc+ with Lughn algorithm.
+  def luhn?(cc)
+    digits = cc.split(//).map(&:to_i)
+    last   = digits.pop
+
+    products = digits.reverse.map.with_index do |n,i|
+        i.even? ? n*2 : n*1
+    end.reverse
+    sum = products.inject(0) { |t,p| t + p.to_s.split(//).map(&:to_i).inject(:+) }
+    checksum = 10 - (sum % 10)
+    checksum == 10 ? 0 : checksum
+
+    ( last == checksum )
+  end
+
+end
+end
+end