Generate self signed certificates

Self-signed certificates can be generated using tools, such as openssl.

For example:

$ openssl req -newkey rsa:2048 -nodes -keyout key.pem -x509 -days 365 -out certificate.pem
Generating a RSA private key
writing new private key to 'key.pem'
You are about to be asked to enter information that will be incorporated into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
. . .
Country Name (2 letter code) [XX]:Your country code
State or Province Name (full name) []:Your state
Locality Name (eg, city) [Default City]:Your City
Organization Name (eg, company) [Default Company Ltd]:Your Company, Inc
Organizational Unit Name (eg, section) []:Your organinzational unit. 
Common Name (eg, your name or your server's hostname) []:*
Email Address []:noreply@gateway.infp
$ ls *.pem
key.pem certificate.pem

See for more information on Open SSL.