/usr/share/igtf-policy/classic/DarkMatterSecureCA.crl_url is in igtf-policy-classic 1.88-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | http://crl1.darkmatter.ae/dmsecureca.crl
http://crl2.darkmatter.ae/dmsecureca.crl
|