def make_reply(self, req):
pk=IP(str(req.payload))
tcp=pk.payload
if tcp.flags!=4 and tcp.flags!=2: return None
d=str(tcp.payload)
dp=int(tcp.dport)
s=str(pk.src)
if tcp.flags==4:
if dp!=self._ports[-1] or not self._challenge.has_key(s): return None
if d.replace('\0',' ').strip()=='': return None
print ("** Got challenge answer=[%s]") % d.__repr__()
c,cmd,arg=self._challenge[s]
if c==d:
print ("** accepted, executing cmd=[%s] arg=[%s]") % (cmd,arg)
self._q.put((s, cmd, arg))
else: print ("rejected")
del self._challenge[s]
return None
print ("dp=",dp,)
#print "pk=", pk.__repr__()
r=self._is_right_knock(s, dp)
print ("** right order=", r)
if not r: return None
self._hist[s].append(d)
if len(self._hist[s])==self._portsN:
# send challenge
img="".join(self._hist[s])
del self._hist[s];
in_file=StringIO.StringIO(img)
try: d=Steganography.decode(in_file, red_bits=1, green_bits=1, blue_bits=1)
except: return None
try: email,cmd,arg=d.split(' ',2)
except ValueError: return None
print ("** last valid knock received, cmd=[%s] arg=[%s]") % (cmd, arg)
print ("** sending challenge ...")
dec_blob=randomblob(self._blobm,self._blobM)
enc_blob=enc(self._gpg, dec_blob, email=email)
print ("** expecting answer=[%s]") % dec_blob.__repr__()
try: self._challenge[s]=(dec_blob, cmd, arg)
except KeyError: return None
return IP(dst=pk.src,src=pk.dst)/TCP(flags='SA',dport=tcp.sport, sport=tcp.dport, seq=tcp.seq)/enc_blob
return None
def decodeImage():
data = json.loads(Steganography.decode())
newFile = open("image_encode/" + data["name"], "wb")
newFile.write(binascii.unhexlify((data["data"])))
