SSL Labs: New Grades for Trust (T) and Mismatch (M) Issues

In the 1.10.x code branch of SSL Labs, which was deployed to production last week, we made a change in how we handle assessments with trust issues. Previously, all certificates that we couldn’t validate (largely because they were self-signed or issued from a private CA root) were given an F grade. In this latest version, we introduced two new grades:

• Trust issues (T); If we don’t trust a certificate (and there aren’t any other security issues), we assign it a T grade (for “trust)”. This grade is thus used when the server is otherwise well-configured. Just below the T grade, we note the grade the server would get if the trust issues were resolved.
• Name mismatch issues (M); In some cases, trust issues come from name mismatches and usually when a server doesn’t actually use encryption. Such sites now get an M grade (for “mismatch”).

I expect the introduction of these new grades is going to help our users better understand what’s really going on.