I have a website which is up and running and has a SSL certificate that I bought, I didn't know about Let's Encrypt at the time.

I am planning a re-write of the application. I'm moving it to ReactJS, so I am building a .Net Core API to drive that.


I wish the api to sit at https://api.bejebeje.com, so I went ahead and using Certify SSL Manager got myself an SSL certificate.

My bindings look like this:

enter image description here

I can access my site via https://api.bejebeje.com/api/artists/ but the SSL isn't green in Chrome or Firefox, it says I have a name mismatch.

Why is this happening and how do I fix it?

Any help would be greatly appreciated.


2 Answers 2


In your server certificate, the CN (Common Name) value is "www.bejebeje.com":

Subject: OU=Domain Control Validated, OU=PositiveSSL, CN=www.bejebeje.com

The DNS Subject Alternative Names (SANs) are "www.bejebeje.com" and "bejebeje.com":

X509v3 Subject Alternative Name: 
    DNS:www.bejebeje.com, DNS:bejebeje.com

These names do not match the requested name of "api.bejebeje.com"; I suspect that's the mismatch. If you can, I'd recommend re-issuing that certificate with "api.bejebeje.com" added as a DNS SAN.

  • hmm but I'm wanting api.bejebeje.com to have its own separate certificate from bejebeje.com?
    – J86
    Aug 18, 2017 at 15:01
  • That's possible as well; it's a question of convenience for you, really (two different certificates vs one certificate for the different sites). If you do create a new separate certficate for api.bejebeje.com, just make sure that it has a DNS SAN for that name; having the CN have that name as well won't hurt.
    – Castaglia
    Aug 18, 2017 at 15:04
  • Under my DNS settings, I am not seeing SAN? I have A, AAAA, CNAME and MX records with some more, but SAN isn't among them.
    – J86
    Aug 18, 2017 at 15:06
  • No no; "DNS SAN" refers to an attribute of the SSL certificate. There are multiple types of "Subject Alternative Names"; a _DNS name is just one of those types.
    – Castaglia
    Aug 18, 2017 at 15:08
  • Also check the issuer; the cert I see (from is Comodo (hence the PositiveSSL branding) not LetsEncrypt. Note this IPaddress is the same as for www and 'naked'; should it be? Aug 18, 2017 at 15:25

It turns out I didn't have Require Server Name Indication turned on for the other HTTPS domain!

I had it for api.bejebeje.com, but I did not have it on for bejebeje.com.

When I turned it on (in Bindings) for that and cleared my browser cache, the problem went away. I now do not get the browser warnings about the name mismatch.


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