/usr/share/igtf-policy/classic/DigiCertGridCA-1-Classic.crl_url is in igtf-policy-classic 1.79-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | http://crl3.digicert.com/DigiCertGridCA-1.crl
http://crl4.digicert.com/DigiCertGridCA-1.crl
|