Each SSL certificate has its own signature.

When I check the site's certificate by visiting the page and using:

right-click > View Page Info > Security tab > View Certificate

I get:

Common name: ssl920622.cloudflaressl.com

SHA1 Fingerprint: 5B:20:E3:43:13:69:94:69:68:B4:56:4A:5C:50:32:12:B7:3B:CF:2C

If GRC shows a different Common name, that's a different certificate. Probably some kind of CDN/Load Balancing thing.

The certificate fingerprint should alway be the same as it is tied to the certificate and does not matter how many load balanacers. An example is youtube.

My certificate is as enclosed and does not match official fingerprint from GRC.

Mace2 said

My certificate is as enclosed and does not match official fingerprint from GRC.

How did you get that certificate for cloudflare-dns.com?

Neither of us got that certificate yesterday.

While connected directly to my ISP vmedia I simply go to one.one.one.one/help and look at the certificate information.

I now get your SHA1 Fingerprint: 5B:20:E3:43:13:69:94:69:68:B4:56:4A:5C:50:32:12:B7:3B:CF:2C as of Oct-10-2019. I would not expect the fingerprint to change.

however it still doesn't match GRC fingerprint which still remains one.one.one.one ssl920621.cloudflaressl.com — 01:31:4A:78:20:82:00:D4:40:AC:55:B9:41:92:08:76:81:A4:0C:B8

Compare the certificate common names.

I don't think the common name matters. The below shows both the one.one.one.one certifcate and the GRC site fingerprint. The SHA1 values should match.

Mace2 said

I don't think the common name matters. The below shows both the one.one.one.one certifcate and the GRC site fingerprint. The SHA1 values should match.

They don't match because they are different certificates.

• One is for ssl920621.cloudflaressl.com
• One is for ssl920622.cloudflaressl.com

Yes. I know but I only enter one site for verification of the fingerprint.

Is there a method to verify the fingerprint for one.one.one.one ?

Becuase I cannot verify the fingerprint and consider this a possible security issue I will state what I did again.

I am only checking ONE fingerprint. The fingerprint I am checking is for https://one.one.one.one the fingerprint vale for that site is sha1:66:56:84:01:72:B4:FB:BC:D6:D0:A4:A1:03:49:1E:93:00:4D:19:5F

To verify that the site fingerprint is correct I go to the web site by GRC.com “https://www.grc.com/fingerprints.htm” and it tells me the fingerprint is incorrect the value for sha1 is 01:31:4A:78:20:82:00:D4:40:AC:55:B9:41:92:08:76:81:A4:0C:B8.

The issue I have is the mismatch with the fingerprint sha1 values

A different fingerprint indicates a different certificate. You and GRC get different certificates for the same host name. What could explain that?

If you think GRC is authoritative, please ask them how it's possible.

When the GRC performs a certificate validation for any site other than Cloudflare the fingeprint value (SHA1 value) always matches. Cloudflare is the only site that I came across that does not validate.

The website https://one.one.one.one/ is both a web site and a D.O.H. address. I am only comparing GRC fingerprint to value sha1 01:31:4A:78:20:82:00:D4:40:AC:55:B9:41:92:08:76:81:A4:0C:B8 and it does not match the cloudflare certificate value.

I will see if I can pose the question to GRC.