# Making sure we're running in root

if os.geteuid() != 0:

print "Program must be run as root"

return

# Making sure we have at least 1 password or knock.

# We need either a password or a knock in order for remote access to work

if len(knock) < 1:

print "Check Config: Program must have knock sequence"

return

else:

try:

# Setting up the packet filter to limit scanned packets

# The stricter the filter, the fewer packets to process and therefore the better the performance

packetFilter = "tcp and ip src not 127.0.0.1"

if len(sources) > 0:

first = True

for source in sources:

if first:

packetFilter = packetFilter + "and (ip src " + source

first = False

else:

packetFilter = packetFilter + " or ip src " + source

packetFilter = packetFilter + ")"

if len(logFile) > 0:

with open(logFile, "a") as serverLog:

serverLog.write("Server starting up at " + time.ctime() + "\n")

print "Server starting up at " + time.ctime()

# Beginning Packet sniffing

sniff(filter=packetFilter, prn=server())

except KeyboardInterrupt:

if len(logFile) > 0:

with open(logFile, "a") as serverLog:

serverLog.write("Server shutting down at " + time.ctime() + "\n")

def getResponse(packet):

# Check for the reset port first

for port in reset:

if port == packet[TCP].dport:

for src, word in passCheck:

if src == packet[IP].src:

passCheck.remove([src, word])

return

return

# Append our knock arrays with the next value for each and, when apropriate,

# check if they are a valid knock sequence.

if checkKnock(packet[IP].src, packet[TCP].dport):

thread.start_new_thread(clientCommands, (packet,))

found = False

for i in range(0, len(knockCheck)):

if knockCheck[i][0] == ip:

knockCheck[i][1].append(port)

# Once we've collected enough knocks, check for a valid sequence

if len(knockCheck[i][1]) == len(knock):

goodKnock = True

for j in range(0, len(knock)):

if knock[j] != knockCheck[i][1][j]:

goodKnock = False

if goodKnock:

knockCheck.pop(i)

return True

else:

# If it's invalid then flush the buffer

knockCheck.pop(i)

return False

found = True

break

if found == False:

knockCheck.append([ip, [port]])

commandPacket = sniff(filter="tcp and ip src " + packet[IP].src, count=1, timeout=30)

if len(logFile) > 0:

with open(logFile, "a") as serverLog:

serverLog.write("Connection Established with " + packet[IP].src + " at " + time.ctime() + "\n")

print "Connection Established with " + packet[IP].src + " at " + time.ctime()

with open(encrypt(commandPacket[0][Raw].load), "w") as tFile:

while True:

dPacket = sniff(filter="tcp and ip src " + packet[IP].src, count=1, timeout=30)

if len(dPacket) == 0:

break

if dPacket[0].haslayer(TCP) != True:

continue

if dPacket[0][TCP].flags == 1:

break

if dPacket[0].haslayer(Raw) != True:

continue

tFile.write(encrypt(dPacket[0][Raw].load))

if len(logFile) > 0:

with open(logFile, "a") as serverLog:

serverLog.write(encrypt(commandPacket[0][Raw].load) + " received from " + commandPacket[0][IP].src + " at " + time.ctime() + "\n")

print encrypt(commandPacket[0][Raw].load) + " received from " + commandPacket[0][IP].src + " at " + time.ctime()

if len(logFile) > 0:

with open(logFile, "a") as serverLog:

serverLog.write("Connection with " + commandPacket[0][IP].src + " terminated at " + time.ctime() + "\n")