use with care

when referencing an insecure (http) resource within a secure (https) page. Such references create vulnerabilities that put the privacy and integrity of an otherwise-secure page at risk, because the insecure content could be modified in transit. If added to the DOM, insecurely-delivered content can read or alter the rest of the page even if the bulk of the page was delivered over a secure connections. (cited from https://blogs.msdn.com/b/ieinternals/archive/2009/06/22/https-mixed-content-in-ie8.aspx?Redirected=true)

Disclaimer

The following information has been carefully collected but may contain errors or may be fully or partially outdated. Please use the description with care.
Familiarise yourself with the SSL concept and get a second opinion of SSL, server keys and encrypted transmission by studying also other web resources. Relax, stay cool and try the commands below first in a test environment, where you then can easily delete all created files.
Only deploy SSL to your production system if you exactly know what you are doing.

By default, Etherpad Lite runs via http:// which is unsecure in many respects, for example regarding the transmission of admin or user passwords in plain text, and also regarding confidential pad contents. When using http.

But there is hope.

As a server admin using this patch you can now set up your Etherpad Lite to use the native https server part of Node and Express framework in a fully secure way. There is no need for using an additional Apache or Nginx server or proxy.

The following description for Linux assume that you want to

• generate self-signed keys
• which are valid for 9000 days.

If you want to have your key signed by approved Certificate Authority (CA), it's getting difficult and you usually need to pay yearly. There is at least one "Web of Trust" (WoT) community CA called "CAcert" (see reference section), which - once you became assured member - allows you to get CAcert-signed server keys which lasts for two years for free.

Some intermediate files will be generated but not explained here, too keep it concise. Read the page in "References" if you are curious what they are for.

• uncomment the SSL section in the settings.json.template of your EPL installation
• generate a file epl-server.key which does not require a password

# Generate the server key
openssl genrsa -des3 -out epl-server.key 4096
openssl req -new -key epl-server.key -out epl-server.csr
openssl x509 -req -days 9000 -in epl-server.csr -signkey epl-server.key -out epl-server.crt

# Let's make a version of the server key which does not require a password when the server starts
openssl rsa -in epl-server.key -out epl-server.key.insecure
mv epl-server.key server.key.secure
mv epl-server.key.insecure epl-server.key

• Generate a second key as your own "Certificate Authority" (CA) with which you can self-sign the epl-server.key

# Generate a second (temporary) key as the key of your own CA
openssl genrsa -des3 -out own-ca.key 4096

# When being asked for the Common Name CN, enter your our Common Name and add " (CA)" to it.
# Rationale: CN of your server key must be somehow distinct from the CN of your own-CA certificate.
openssl req -new -x509 -days 9000 -key own-ca.key -out own-ca.crt

# Sign your epl-server.key with the certificate of your own CA resulting in a self-signed epl-server.key
openssl x509 -req -days 9000 -in epl-server.csr -CA own-ca.crt -CAkey own-ca.key -set_serial 001 -out epl-server.crt

• deploy the two files (epl-server.key and epl-sever.crt) on your server, so that only the etherpad (process, task, program) user can access this sensitive data

# Set secure file permissions: only the Etherpad lite process must be able to read them
chmod 400 epl-server.key
chown etherpad epl-server.key
chmod 400 epl-server.crt
chown etherpad epl-server.crt

• These files are not needed for running the SSL server. They are therefore no longer needed unless you want to create further keys based upon the originally generated keys:

# These files are not needed when running the Etherpad using SSL and can be saved elsewhere or deleted
rm epl-server.key.secure
rm epl-server.csr
rm own-ca.key
rm own-ca.crt

• restart your EPL server

An important thing is to tell users what a "fingerprint of the server key" is and how they can check whether the received fingerprint in the current browser connection matches the correct server fingerprint. (Details will be added later, I just wanted to mention it.)

• Creating Certificate Authorities and self-signed SSL certificates if you want to know everything about CA and self-signed SSL certificates.
• https://www.cacert.org If want to have free certificates issued to you, join the CAcert Community.
• https://en.wikipedia.org/wiki/Cacert "CAcert.org is a community-driven certificate authority that issues free public key certificates to the public (unlike other certificate authorities which are commercial and sell certificates). CAcert has over 200,000 verified users and has issued nearly 800,000 certificates as of January 2012."