Verify a certificate chain using openssl verify

Question

I\'m building a own certificate chain with following componenents:

Root Certificate - Intermediate Certificate - User Certificate

Root Cert

Answer 1

I've had to do a verification of a letsencrypt certificate and I did it like this:

1. Download the root-cert and the intermediate-cert from the letsencrypt chain of trust.

2. Issue this command:

   $ openssl verify -CAfile letsencrypt-root-cert/isrgrootx1.pem.txt -untrusted letsencrypt-intermediate-cert/letsencryptauthorityx3.pem.txt /etc/letsencrypt/live/sitename.tld/cert.pem 
   /etc/letsencrypt/live/sitename.tld/cert.pem: OK