Downloads Certificate Revocation Lists

 This tool and associated timer (systemd) or cron (init.d) entry
 ensure that Certificate Revocation Lists (CRLs) are periodically
 retrieved from the web sites of the respective Certification
 Authorities.
 .
 The fetch-crl tool finds all *.crl_url files in the configured CRL
 directory, downloads the CRLs listed in those files and saves them in
 the same directory. The default configuration uses
 /etc/grid-security/certificates as the CRL directory.