Raspberry Pi

Edit SSH server port

1. Open file /etc/ssh/sshd_config
2. Change line Port 22
3. Restart service sudo service ssh restart

Disable password authentication

1. Open file /etc/ssh/sshd_config
   
2. Change line PasswordAuthentication no
   
3. Restart service sudo service ssh restart
   

Export SSH tunnels

GatewayPorts yes in /etc/ssh/sshd_config

[ Source: https://www.linuxquestions.org/questions/linux-networking-3/ssh-tunnel-only-listening-on-loopback-device-should-also-listen-on-eth0-703465/ ]

SSH tunnel

At remote server:

ssh -p 443 -R 19999:localhost:22 user@home

This assumes that home has SSH server on port 443. Home will have additional SSH server on port 19999 that will tunnel to remote server.

Long SSH connections

Prevents the "broken pipe". In .ssh/config:

ServerAliveInterval 60
ServerAliveCountMax 1000

ddclient external IP

By default ddclient will use internal IP. Edit /etc/ddclient.conf

protocol=dyndns2
use=web, web=myip.dnsdynamic.com
server=www.dnsdynamic.org
login='user'
password='password'
mydomain.com

Install dig

sudo apt-get install dnsutils

Change shell to bash

First check the shell you are using:

ps -p $$

chsh user --shell /bin/bash

Test internet connection speed

git clone https://github.com/sivel/speedtest-cli

Build nginx from source

With SPDY support included!

See: http://nginx.org/en/linux_packages.html#mainline

Add signing key from http://nginx.org/keys/nginx_signing.key

wget http://nginx.org/keys/nginx_signing.key
sudo apt-key add nginx_signing.key

Edit /etc/apt/sources.list and add:

deb http://nginx.org/packages/mainline/debian/ codename nginx
deb-src http://nginx.org/packages/mainline/debian/ codename nginx

Where codename for current Raspberry Pi OS will be wheezy.

As the repository doesn't contain binaries we need to build nginx from source:

sudo apt-get update
sudo apt-get -y install build-essential debhelper libpcre3-dev 
apt-get -b source nginx
sudo dpkg -i --force-overwrite nginx...deb

Nginx configuration

Check configuration:

sudo nginx -t

Restart only when configuration is valid:

sudo /etc/init.d/nginx reload

Nginx SSL configuration

server {
        listen 443 ssl spdy;
        server_name server_name;
        server_tokens off;

        ssl on;
        ssl_certificate /etc/nginx/conf.d/ssl-unified.crt;
        ssl_certificate_key /etc/nginx/conf.d/ssl.key;

        ssl_stapling on;

        ssl_session_cache shared:SSL:10m;
        ssl_session_timeout 10m;

        ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
        ssl_ciphers ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:ECDHE-RSA-RC4-SHA:ECDHE-RSA-AES128-SHA:RC4:HIGH:!MD5:!aNULL:!EDH;
        ssl_prefer_server_ciphers on;

        location / {
                proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
                proxy_redirect off;
                proxy_buffering off;
                proxy_set_header X-Forwarded-Host $host;
                proxy_set_header X-Forwarded-Server $host;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header Host $host;
                proxy_pass http://127.0.0.1:8080/;
                add_header Strict-Transport-Security "max-age=31536000; includeSubdomains";
                add_header X-Frame-Options SAMEORIGIN;
        }
}

Decrypt private key

openssl rsa -in ssl.key -out ssl.key

Concatenate certificates

wget https://www.startssl.com/certs/ca.pem
wget https://www.startssl.com/certs/sub.class1.server.ca.pem