Nix: SSH

TCP 22: normal
Server Config:
- /etc/ssh/sshd_config
- https://www.ssh.com/academy/ssh/sshd_config
Versions:
- v1: obselete and vuln to MITM
- v2: modern

Dangerous Settings

https://www.ssh-audit.com/hardening_guides.html

Setting	Description
`PasswordAuthentication yes`	Allows password-based authentication.
`PermitEmptyPasswords yes`	Allows the use of empty passwords.
`PermitRootLogin yes`	Allows to log in as the root user.
`Protocol 1`	Uses an outdated version of encryption.
`X11Forwarding yes`	Allows X11 forwarding for GUI applications.
`AllowTcpForwarding yes`	Allows forwarding of TCP ports.
`PermitTunnel`	Allows tunneling.
`DebianBanner yes`	Displays a specific banner when logging in.

# Audit sercurity of SSH server
# https://github.com/jtesta/ssh-audit
git clone https://github.com/jtesta/ssh-audit.git && cd ssh-audit
./ssh-audit.py -l warn <TARGET> | tee ssh_audit.txt

# Specify auth-method: password
ssh -v -o PreferredAuthentications=password <USER>@<TARGET>

sshpass -p '<PASSWORD>' ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 22 <USER>@<TARGET>

# Force auth-method: privkey
ssh -i <PRIVATE_KEY> <USER>@<TARGET>