OracleLinux9.3 ; SSL Certificate Acquisition( Let's Encrypt ) , WEB/Mail server SSL
1. SSL Certificate Acquisition ( Let's Encrypt )
Install the latest open ssl
# dnf install openssl-devel
1.1 advance preparation
1.Package management system Snappy installation
Since the SSL certificate issuing tool "certbot" of Let's Encrypt is recommended to be installed using "snap" after 2021, install Snapd first.(Can also be installed the traditional way with dnf or yum)
2. Converting Apache to https
Install the following
# dnf -y install mod_ssl
2.1 Edit ssl.conf file
3. SSL/TLS (Let's Encrypt) settings on the mail server
3.1 Obtaining a certificate for the mail server
Obtain a certificate for the mail server, but it cannot be obtained in the same way as above, so the following with the "--standalone" option fails.