Introduction to Network Programming with Python

Let's understand how devices talk to each other through the network by looking at the network packets, creating them and sending our very own packets into the wild network using Scapy, a library to build networking applications and manipulate packets with Python.
This was presented during @hackingmx meetup #4, on @hackerGarage in Guadalajara, Jalisco, Mexico.

Transcript

1. Introduction to Network Programming with Python Rafael Santos @Tucif Hacking.mx meetup
2. • Why? • Network Packets • Packets and Python • Demo Network Programming with Python
3. Why? With most tools you won't build someting the author did not imagine. To stop being an script kiddie. It's fun!
4. Let's talk a bit about networking How/Why does the internet work? How does my machine talk to others?
6. IP
7. But what if the packet is.. manipulated? captured? sent to other place? ...
8. Wait a minute.. Who creates the packets? Can I create my own packets?
9. Scapy • Written in Python • Command-line interactive • TCP,IP,ICMP,ARP,... • Easy encapsulation • Decodes but doesn't interpret
10. Scapy Creating an IP packet: >>> ip = IP() >>> ip.dst = "127.0.0.1" >>> ip <IP dst=127.0.0.1 |>
11. Sending packets send(IP(dst="10.1.99.2")/ICMP()/"HelloWorld") I can do that with a simple ping!
12. Sending evil packets send(IP(src="10.1.99.100", dst=" 10.1.99.2")/ICMP()/"HelloWorld")
13. Demo time! Let's build a Port Scanner!
14. scanPacket = IP(dst='192.168.1.177')/TCP (dport=8080,sport=459) #sendReceive sr(scanPacket) Scanning Ports
15. Interpreting results IP / TCP 192.168.1.185:(sport) > 192.168.1.177:(dport) S ==> IP / TCP 192.168.1.177:(dport) > 192.168.1.185:(sport) SA
16. References Warriors of the Net (warriorsofthe.net) The TCP/IP Guide (TCPIPGuide.com) The Very Unofficial Dummies Guide to Scapy (scapy-guide.googlecode.com) Scapy Official docs (http://www.secdev. org/projects/scapy/doc/)
17. Q & A @Tucif