What knowledge is needed to intercept data?

Question

linux

I have basic knowledge in programming (Pascal, C, html, a little php, I'm learning ruby).

What is needed in order to write your own sniffer, like, for example, the same one - DroidSheep?
Thanks in advance for your kind replies.

Answer 1

IMHO all sniffers have been written for a long time. I recommend to get acquainted with pcap. This is a library for capturing network packets. The whole value of a sniffer today lies in the analysis of intercepted traffic, and for this you need to read the descriptions of the protocols that you want to intercept. In the case of android, for example, you can try to call native code through JNI, intercept packets, and then transfer them to Java and fight them further there.

Answer 2

What about writing it? A sniffer is just an open socket in promicious mode. Opens in 3 lines in any language) The complexity of the sniffer lies more in the interface and the analyzer of various protocols