Matrix Synapse on Ubuntu 16.04

Customize guide

Replace “[email protected]” with desired email address for Let's Encrypt notifications.
Replace “esko.bar” with your domain.

Set DNS

_matrix._tcp.esko.bar SRV 10 0 8448 matrix.esko.bar.
matrix.esko.bar A 165.227.138.149

Update Ubuntu

ssh [email protected]

dpkg-reconfigure --priority=low unattended-upgrades

apt update && apt -y upgrade

reboot

ssh [email protected]

Install Nginx

apt install -y nginx

Generate Diffie–Hellman

Start this now to save time, or use the alternative quicker way.

tmux
openssl dhparam -out /etc/nginx/dhparam.pem 4096

Press Control–B + C to create and open new virtual terminal.
Press Control–B + D to detach from Tmux and return to shell.
Run tmux a to reattach to Tmux.

Alternative (faster)

https://security.stackexchange.com/a/95184

openssl dhparam -dsaparam -out /etc/nginx/dhparam.pem 4096

Add Matrix repository

apt-add-repository -y https://matrix.org/packages/debian/
wget https://matrix.org/packages/debian/repo-key.asc -O matrix-repo-key.asc
apt-key add - < matrix-repo-key.asc

Install Matrix Synapse

apt update
apt install -y matrix-synapse

Enter server name: esko.bar
Decide about sending usage data.

Configure Matrix Synapse

synapse_registration_shared_secret=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 32 | head -n 1)
sed -i'' "s/^\(# registration_shared_secret: <PRIVATE STRING>\)$/\1\nregistration_shared_secret: \"${synapse_registration_shared_secret}\"/" /etc/matrix-synapse/homeserver.yaml

synapse_public_baseurl="https://matrix.esko.bar/"
sed -i'' "s%^\(# public_baseurl: https:\/\/example.com:8448\/\)$%\1\npublic_baseurl: \"${synapse_public_baseurl}\"%" /etc/matrix-synapse/homeserver.yaml

sed -i'' "s%^\(allow_guest_access: \)False$%\1True%" /etc/matrix-synapse/homeserver.yaml

vim /etc/matrix-synapse/homeserver.yaml

Set bind_addresses: ['127.0.0.1'] and x_forwarded: true for port 8008 in homeserver.yaml.

Consider URL previews (broken?)

sed -i'' "s%^\(url_preview_enabled: \)False$%\1True%" /etc/matrix-synapse/homeserver.yaml

Set blacklist for url_preview using suggestion in comments.

Configure UFW

ufw allow ssh/tcp
ufw allow 8448/tcp
ufw allow 80/tcp
ufw allow 443/tcp
ufw enable
ufw status

Install Certbot

apt-add-repository -y ppa:certbot/certbot
apt update
apt install -y python-certbot-nginx

Configure Nginx

rm /etc/nginx/sites-enabled/default

Add matrix.esko.bar.conf to /etc/nginx/conf.d

server {
    server_name  chat.nubits.com;
    listen  80;
    listen  [::]:80;

    if ($scheme != "https") {
        return 301 https://$host$request_uri;
    } # managed by Certbot

}
server {
    server_name  chat.nubits.com;
    listen       443 ssl http2;
    listen       [::]:443 ssl http2;

    ssl_dhparam  /etc/nginx/dhparam.pem;

    ssl_ciphers     EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH;
    ssl_ecdh_curve  secp384r1; # Requires nginx >= 1.1.0
    ssl_protocols   TLSv1.2;

    ssl_prefer_server_ciphers  on;
    ssl_session_cache          shared:SSL:10m;
    ssl_session_tickets        off; # Requires nginx >= 1.5.9
    ssl_stapling               on; # Requires nginx >= 1.3.7
    ssl_stapling_verify        on; # Requires nginx >= 1.3.7

    #add_header  Strict-Transport-Security "max-age=63072000; includeSubdomains; preload";
    add_header  X-Content-Type-Options nosniff;
    #add_header  X-Frame-Options DENY;

    resolver          8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout  5s;

    location /_matrix {
        proxy_pass http://localhost:8008;
        proxy_set_header X-Forwarded-For $remote_addr;
    }
}

Consider (optional)

apt install -y nginx-extras

Add to Nginx configuration:

server_tokens off;
more_clear_headers 'Server';
more_clear_headers 'X-Powered-By';

Check Nginx configuration

nginx -t

Start Nginx

systemctl enable nginx
systemctl start nginx

Acquire TLS certificate

certbot -n --nginx --agree-tos --no-eff-email --rsa-key-size 4096 --redirect --email [email protected] -d matrix.esko.bar

Enable automatic renewal

crontab -e

Insert:

15 3 * * * /usr/bin/certbot renew --quiet

Start Synapse

sudo systemctl enable matrix-synapse.service
sudo systemctl start matrix-synapse.service

Create user

register_new_matrix_user -c /etc/matrix-synapse/homeserver.yaml https://localhost

Check

curl https://matrix.esko.bar/_matrix/key/v2/server/auto

https://matrix.org/federationtester/api/report?server_name=esko.bar

jooize/matrix-synapse-on-ubuntu-16.04.markdown