CentOS is a Linux distribution based on Red Hat Enterprise Linux. Does this mean SiteMinder is supported on CentOS?
CentOS is not a supported platform and therefore not listed in SiteMinder Platform Support Matrix.
While the policy server and agent have not been certified or tested on CentOS, we We do support customers using variants of the Linux operating systems according to the Linux Reasonable Commercial Effort section in our PRODUCT SUPPORT MATRIX
https://support.broadcom.com/external/content/release-announcements/Layer7-SiteMinder-previously-CA-SSO-platform-support-matrices/6578#PSM
Having said so, you can try using the latest 12.52 SP1 CR10 agent on CentOS7 taking into consideration the below KB article to address the changes in Linux 7
https://knowledge.broadcom.com/external/article/4165/systemctl-and-web-agent-startup-settings.html