For those who have used the NSX vSphere REST API, you will know that with every API call you are required to send the following in the headers:

Content-Type      application/xml
Basic             <base64 encoded credentials>

So if you have an OSX machine, you can leverage openssl (which is installed by default) to generate the base64 encoded credentials. This means you do not have to find a website and paste credentials into the site to generate the encoded credentials.

The command is as follows

echo -n '<username:password>' | openssl base64

So to generate the credentials for a default username of admin and a password of ‘default’, you would perform the following:

echo -n 'admin:default' | openssl base64

Which will spit out the credentials

SneakU$ echo -n 'admin:default' | openssl base64
YWRtaW46ZGVmYXVsdA==
SneakU$