Network

Xarxes: SSH, TLS i certificats, servidors web i proxies, VPN, i anàlisi i detecció de trànsit.

Fonaments

De què està feta una xarxa, i les tres coses que una màquina necessita per parlar-hi.

What a network is made of, how far each kind reaches, and why the drawing of the cables and the drawing of the addresses are two different drawings.

An address, a route and a port — the three things a machine needs before any of your programs can talk to anything.

TLS provides confidentiality and authenticity between two applications at the socket level

Deploy an HTTPS server by signing the same certificate three times - self-signed, with your own authority, and with Let's Encrypt.

SSH gives you a shell on a machine that is not yours, and the whole protocol is one question asked twice — who is the server, and who are you?

Wireguard provides confidentiality and authenticity between two IP addresses

Nginx, besides being a web server, is also a reverse proxy.

Fes passar les teves connexions per un proxy.

Envoy is the proxy that takes care of locating services, distributing requests and retrying them, so that the application doesn't have to.

Nmap explora una xarxa i descobreix quins serveis hi ha escoltant.

A vulnerability scanner doesn't look for open ports but for known holes - deploy Greenbone and turn its report into a risk analysis.

A firewall that looks inside packets - write IDS/IPS signatures and block traffic by content, by protocol and by country.

tcpdump reads packets off the wire and shows you the headers inside.

Arkime captura i indexa el trànsit de xarxa perquè el puguis cercar després.