Reference document for quick configuration of self-signed certificate for WebVPN on an ASA.
-The URL for your webvpn should be used as the fqdn and subject-name in the trustpoint config. If they do not match, you will see errors about a mismatch when you access your webvpn URL and the certificate is presented.
-This is a self-signed cert. That means the end users browser does not have any knowledge of the ASA as a CA authority. This means you have to install the cert the first time it is presented to say you trust the ASA as a CA authority. You should only need to install it once.