TLS

See: http://www.postfix.org/TLS_README.html#quick-start

testbox1 root # /etc/ssl/misc/CA.pl -newca
CA certificate filename (or enter to create)

Making CA certificate ...
Generating a 1024 bit RSA private key
...............................++++++
.....................................++++++
writing new private key to './demoCA/private/cakey.pem'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
...
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.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
...
Country Name (2 letter code) [AU]:UK
State or Province Name (full name) [Some-State]:Devon
Locality Name (eg, city) []:Okehampton
Organization Name (eg, company) [Internet Widgits Pty Ltd]:PKOpen
Organizational Unit Name (eg, section) []:
Common Name (eg, YOUR name) []:Patrick
Email Address []:me@mail.com

testbox1 root # ls -l /root/demoCA/private/cakey.pem
-rw-r--r--  1 root root 963 Feb 12 11:13 /root/demoCA/private/cakey.pem