Wednesday, November 16, 2016

Netcat HTTP server

Netcat is a very versatile program used for network communications - the place to find it is .

Often I need to test different programs with a dummy HTTP server, so using netcat for this is very easy.

Lt's say you want to respond with HTTP code 200 ... this is what you do with netcat into a shell

 nc -k  -lp 9000 -c 'echo "HTTP/1.1 200 OK\nContent-Length:0\nContent-Type: text/html; charset=utf-8"' -vvv -o session.txt

To explain the switches used:
  • -k accept multiple connections, won't stop netcat after first connection(default)
  • -l listen TCP on the all interfaces
  • -p the port number to bind
  • -c 'echo "HTTP/1.1 200 OK\nContent-Length:0\nContent-Type: text/html; charset=utf-8"' is the most interesting one ... this responds back to the client with a minimal http header and sets code 200 OK
  • -vvv verbosity level
  • -o session.txt netcat will write into this file all the input and output
Now you have a dummy http server running on port 9000 that will answer 200 OK ALL the time :)