I made a site that checked for SSL cert expirations and misconfigurations, but I couldn't acquire any customers. I still think there's a business there somewhere, although maybe it really only sells as part of another product.
Edit: If anyone wants a script to check their certificates, here you go: https://gist.github.com/bretwalker/5420652. You'll just need to add in some sort of notification logic, especially for expirations, since they need to happen before a problem arises.
That's a very interesting idea, Simon, and one that didn't even cross my mind.
I've since moved on to a new project. If anyone wants to talk about taking over the site, shoot me a message at bretwalker /at/ Google's email. It's Django and has some branding and a domain: http://static.nyquistrate.com.s3.amazonaws.com/media/certcia...
Stackify created this exact thing after the last time this happened with MS Azure about 2 months ago. It's called certalert.me (http://certalert.me) and is a free service.
It's not a huge business, but it was almost trivial to setup with all the advanced monitoring & diagnostics that stackify typically does anyway.
Very useful. It's not a super hard problem to solve, but I did think it provided enough value that companies would be willing to pay for it. SSL is used on the most important pieces of a business' infrastructure, I thought it'd be a simple sell.
I also can't tell if certalert.me checks for hostname mismatches. That was another part of my service, because a misconfiguration is just as fatal as an expired certificate.
The sad thing is that SCOM can monitor for pending certificate expiration and validity. If Microsoft dogfooded a little more, they might have seen this.
I usually put a check for "SSL certificate expires in less than 30 days" in the NMS. There is certainly a market for network monitoring as a service and this is a useful check to have in one.
Edit: If anyone wants a script to check their certificates, here you go: https://gist.github.com/bretwalker/5420652. You'll just need to add in some sort of notification logic, especially for expirations, since they need to happen before a problem arises.