Configuring TLS on the AxoSyslog server

Purpose:

Complete the following steps on the AxoSyslog server:

Steps:

1. Copy the certificate (for example, syslog-ng.cert) of the AxoSyslog server to the AxoSyslog server host, for example, into the /opt/syslog-ng/etc/syslog-ng/cert.d directory. The certificate must be a valid X.509 certificate in PEM format.

2. Copy the CA certificate (for example, cacert.pem) of the Certificate Authority that issued the certificate of the AxoSyslog clients to the AxoSyslog server, for example, into the /opt/syslog-ng/etc/syslog-ng/ca.d directory.

   Issue the following command on the certificate: openssl x509 -noout -hash -in cacert.pem The result is a hash (for example, 6d2962a8), a series of alphanumeric characters based on the Distinguished Name of the certificate.

   Issue the following command to create a symbolic link to the certificate that uses the hash returned by the previous command and the .0 suffix.

   ln -s cacert.pem 6d2962a8.0

3. Copy the private key (for example, syslog-ng.key) matching the certificate of the AxoSyslog server to the AxoSyslog server host, for example, into the /opt/syslog-ng/etc/syslog-ng/key.d directory. The key must be in PEM format. If you want to use a password-protected key, see Password-protected keys.

4. Add a source statement to the syslog-ng.conf configuration file that uses the tls( key-file(key_file_fullpathname) cert-file(cert_file_fullpathname) ) option and specify the key and certificate files. The source must use the source driver (network() or syslog()) matching the destination driver used by the syslog-ng client. Also specify the directory storing the certificate of the CA that issued the client’s certificate.

   For the details of the available tls() options, see TLS options.

   Example: A source statement using TLS

   The following source receives log messages encrypted using TLS, arriving to the 1999/TCP port of any interface of the AxoSyslog server.

       source demo_tls_source {
           network(
               ip(0.0.0.0) port(1999)
               transport("tls")
               tls(
                   key-file("/opt/syslog-ng/etc/syslog-ng/key.d/syslog-ng.key")
                   cert-file("/opt/syslog-ng/etc/syslog-ng/cert.d/syslog-ng.cert")
                   ca-dir("/opt/syslog-ng/etc/syslog-ng/ca.d")
               )
           );
       };
   

   A similar source for receiving messages using the IETF-syslog protocol:

       source demo_tls_syslog_source {
           syslog(
               ip(0.0.0.0) port(1999)
               transport("tls")
               tls(
                   key-file("/opt/syslog-ng/etc/syslog-ng/key.d/syslog-ng.key")
                   cert-file("/opt/syslog-ng/etc/syslog-ng/cert.d/syslog-ng.cert")
                   ca-dir("/opt/syslog-ng/etc/syslog-ng/ca.d")        
               )
           );
       };
   

   Warning

   Do not forget to update the certificate and key files when they expire.