In order to display block and warning pages for sites using SSL (Secure Sockets Layer, a standard security technology for establishing an encrypted link between a server and a client) and to access sites that meet the proxy criteria using SSL, you will need to install a Mimecast SSL Certificate.
To accomplish this:
- Download the Mimecast SSL Certificate from the Administration Console via the Web Security | Certificate and DNS Setup menu.
- Check that the SHA-256 hash downloaded to your computer matches the code displayed in the console.
- On Windows machines, use the "get-filehash" powershell command. See the Get-FileHash page of the Microsoft Windows Powershell help for further details.
- On Mac machines, use the "openssl dgst" terminal command. See the Verifying Checksums When You Download an App page of the Apple Forums for further information.
- Deploy the Mimecast SSL Certificate in your organization. Refer to the installation guide for your operating system and browser.
If you're installing the Mimecast Security Agent, the software automatically installs the Mimecast SSL Certificate into your system's keychain / certification root. See the "Browser Recommendations" section of the Mimecast Security Agent installation guide for Windows OS or Mac OS for further information. If you aren't installing the MSA endpoint software, you’ll need to install the Mimecast certificate to provide network level protection for HTTPS websites.