Yesterday, I had a working development site suddenly start throwing SSL errors:
The error message was:
This server could not prove that it is [Server Name] its security certificate is from [missing_subjectAltName]
Huh? What broke this?
Well, it turns out that Chrome had updated to Chrome 58, which removed support for the “Common Name” field. Instead, we’re supposed to use the “Subject Alternative Name” (SAN) field. That’s unfortunate; the IIS ‘Create Certificate Request‘ option we’d used resulted in a certificate with no Subject Alternative Name field. That could be a result of how it was handled – I didn’t create the certificate – but it looks like Windows MakeCert doesn’t handle Subject Alternative Names, so I wouldn’t be surprised if this is a general Windows issue.
The SSL cert continued to work without a SAN just fine in IE, but Firefox and Chrome now demand it, and so were throwing SSL errors.
Now, it seems that the Subject Alternative Name is what we’re actually supposed to use, and that publicly trusted certs have used both fields for years – but in our development server, using our own CA, that wasn’t the case.
See How to Request a Certificate With a Custom Subject Alternative Name.
I was working at a customer recently who’s Sitecore instance wasn’t accessible over HTTPS. It was a single server, and the site itself was working just fine over HTTPS, so that begged the question – why?
The error we were getting was:
Sitecore.Context.ContentDatabase returns null.
We were using HTTPS, and it’s worth noting that rather than redirecting all HTTP traffic to HTTPS with IIS, they were using C# code and a Response.Redirect() call in their page itself, which is… unusual. It also means that HTTP traffic to Sitecore shell is not redirected – the content page layout isn’t loaded, so their redirect wouldn’t happen.
Eventually, I found the following in a patch file:
Interesting. Shell and login were being tied to port 80 – but HTTPS uses 443.
I removed this patch, and suddenly Sitecore was available over HTTPS again.
A quick note to myself – in Chrome you can check your HSTS headers for a site using:
This was a problem for me yesterday, and the UAT system I was configuring wasn’t visible to sites like https://securityheaders.io/ that I’d normally use.
So a Sitecore site I’ve been working on recently underwent a penetration test, which turned up an interesting item. The ASP.NET_SessionId and SC_ANALYTICS_GLOBAL_COOKIE cookies aren’t set with the ‘Secure’ flag. Further, my own checking showed that the .ASPXAUTH token was also set without the ‘Secure’ flag.
As the entire site is only served over HTTPS, this seems to be a bit remiss.
Fortunately, there are a couple of easy fixes to this that can be set in the Web.config
<httpCookies> set requireSSL:
<httpCookies requireSSL="true" />
<forms> set requireSSL too.
<forms name=".ASPXAUTH" cookieless="UseCookies" requireSSL="true" />
This latter one is needed for the .ASPXAUTH cookie, but that seems to do it.
Don’t forget to set the HTTPOnly flag as appropriate for your cookies too!