A certificate authority (CA) issues digital certificates that certify the ownership of a public key by the named subject of the certificate.

Below are a couple of steps to install self-signed trusted Root CA on a Linux server.

Step #1: Install openssl

yum install openssl

Step #2: Creating your own CA

cd /etc/pki/CA/private/
openssl genrsa -aes128 -out ourCA.key 2048

Now create a Certificate Authority (CA) certificate using the ourCA.key.

openssl req -new -x509 -days 1825 -key /etc/pki/CA/private/ourCA.key -out /etc/pki/CA/certs/ourCA.crt

Next, create a local wildcard certificate (*.linuxlab.local) on your own CA.

openssl genrsa -out /etc/pki/tls/private/wildcard-cert.key 2048

Now, generate a CSR (Certificate Signing Request) for the wildcard cert.

openssl req -new -key /etc/pki/tls/private/wildcard-cert.key -out /etc/pki/tls/wildcard.csr

Using WinSCP to download a local Root CA self-signed public-key certificate to a Windows machine. Then, import it into the GPO of the Windows domain or any Windows/Linux/Mac web browser.