Certificate Chain Incomplete

KB ID 0001570


The certificate here at PNL expired over the weekend, I got a new one and installed it. All appeared to be fine until I did an online check to make sure it was OK. 

Certificate Chain Is Imcomplete

The server’s certificate chain is incomplete


I had this problem once before, back then I was using Apache and CentOS7, and things were a little different, (now I’m using NGINX and Ubuntu 18.04). Essentially you see this error because you have bought a ‘cheap‘ SSL certificate. There’s nothing wrong with that per se, but they tend to be issued from an ‘Intermediate CA‘. Again there’s nothing wrong with that either, but to improve your score you need to ‘Embed‘ the intermediate certificate, into your SSL certificate, (or all the intermediates back to a Root CA Server, if you have multiple intermediate certificates!) 

Here I have ONE intermediate, (which is pretty normal.)

Certificate Intermediate CA

There a no special tools you require to be able to do this, other than a simple text editor, you open your SSL certificate and ‘Paste” the intermediate certificate on the bottom. (DO NOT ADD ANY EXTRA SPACES). Like so;

Create Certificate Chain

Note: As you can see, you DON’T put the Root CA certificate at the bottom, (clients should already have them!) I made this mistake then got the following error;

Jun 23 14:12:29 localhost nginx[1197]: nginx: [emerg] PEM_read_bio_X509("/etc/nginx/ssl/www_petenetlive_com.crt") failed (SSL: error:0906D066:PEM routines:PEM_read_bio:bad end line)
Jun 23 14:12:29 localhost nginx[1197]: nginx: configuration file /etc/nginx/nginx.conf test failed

Retry your test.

Fix a certificate chain

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Author: PeteLong

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