ocspd

The "ocspd" command line tool is a part of Apple's macOS operating system. It stands for "Online Certificate Status Protocol Daemon." This tool is responsible for managing the Online Certificate Status Protocol (OCSP) service in macOS. OCSP is used to verify the status of digital certificates issued by Certificate Authorities (CAs).

The ocspd tool runs as a background process and handles the requests made by applications to check the validity of certificates. It communicates with the appropriate OCSP servers to verify the certificate status instead of relying on Certificate Revocation Lists (CRLs).

By utilizing OCSP, ocspd ensures that certificates used for various purposes in macOS, such as secure website connections and digital signatures, are up to date and considered valid. It provides a more efficient and timely approach compared to CRLs, which require periodic updates.

ocspd relies on certificate validation policies set by the system administrator or the security policies defined by the operating system. This ensures that certificate validation occurs according to the desired rules and prevents unauthorized access or attacks.

The ocspd tool can be managed using the command line interface (CLI) by system administrators to control OCSP handling and troubleshoot any issues related to certificate validation. It plays an essential role in maintaining the security and integrity of certificate-based authentication and encryption processes in macOS.