decoding internet packets payload in python

Question

I have used scapy to sniff internet packets from my computer knowing that they are not encrypted how can I decode the data being sent so it comes out as clear text , something like wireshark does, I would like a code exemple for it. I do not want to use wireshark I want to code this myself for learning.

I used the following simple script to capture the packets :

from scapy.all import *

def callback(pkt) :
    print pkt.summary()
    print pkt.show()

sniff(store=0, prn= callback)

Answer 1

It depends on the application that sends the taffic. If it sends the data unencrypted and in plain text (ascii) you can access and display it using the atribute load of the packet. For example:

def callback(pkt) :
    print pkt.load

If the data is not plain text you need to know how the application is encoding the data and decode it. If you're looking for more similar output to that of wireshark you can try with hexdump(pkt).