You can achieve this using OpenSSL. (Mac OSX includes OpenSSL within Terminal.app)
This usually means the implementation of SSL on your server is not correct. The error is usually caused by a server side problem which the server administrator will need to investigate.
Some hosting systems require the Private key to be in RSA format rather than PEM. You can easily convert these files using OpenSSL.
This message is sometimes displayed when accessing an SSL page via a proxy (including our own payment page PayPal).
Running PHP via the FastCGI module on Windows servers means that PHP is executed extremely quickly.
Understanding how multi year HTTPS certificates work.
Enable/Disable Two Factor Authentication on your Servertastic Account
Information about the CyberSmart mobile application designed to assist with Cyber Essentials compliance