ghost@fox:~/.chef$ knife ssl check -VV
DEBUG: Checking SSL cert on https://lion:443/
Connecting to host lion:443
ERROR: The SSL certificate of lion could not be verified
DEBUG: SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed
Certificate issuer data: /C=US/ST=WA/L=Seattle/O=YouCorp/OU=Operations/CN=lion/emailAddress=you@example.com

Configuration Info:

OpenSSL Configuration:
* Version: OpenSSL 1.0.1i 6 Aug 2014
* Certificate file: /opt/chefdk/embedded/ssl/cert.pem
* Certificate directory: /opt/chefdk/embedded/ssl/certs
Chef SSL Configuration:
* ssl_ca_path: nil
* ssl_ca_file: nil
* trusted_certs_dir: "/home/ghost/.chef/trusted_certs"

TO FIX THIS ERROR:

If the server you are connecting to uses a self-signed certificate, you must
configure chef to trust that server's certificate.

By default, the certificate is stored in the following location on the host
where your chef-server runs:

  /var/opt/chef-server/nginx/ca/SERVER_HOSTNAME.crt

Copy that file to you trusted_certs_dir (currently: /home/ghost/.chef/trusted_certs)
using SSH/SCP or some other secure method, then re-run this command to confirm
that the server's certificate is now trusted.

ghost@fox:~/.chef$ knife ssl check -c /etc/chef/client.rb -VV
DEBUG: Checking SSL cert on https://lion:443/
Connecting to host lion:443
Successfully verified certificates from `lion'
ghost@fox:~/.chef$