'Uses aircrack-ng to check for handshake.
Returns True if found, False otherwise.'

def has_handshake_aircrack(self, target, capfile):

    if (not program_exists('aircrack-ng')):
        return False
    crack = ((('echo    ""    |    aircrack-ng    -a    2    -w    -    -b    ' + target.bssid) + '    ') + capfile)
    proc_crack = Popen(crack, stdout=PIPE, stderr=DN, shell=True)
    proc_crack.wait()
    txt = proc_crack.communicate()[0]
    return (txt.find('Passphrase    not    in    dictionary') != (-1))
