Pathfinder provides a mechanism for any program to
perform RFC3280-compliant path validation of X509
certificates, even when some of the intermediate
certificates are not present on the local machine.
It will automatically download any such
certificates and their CRLs from the Internet as
needed using the AIA and CRL distribution point
extensions of the certificates it is processing.
By default, the Pathfinder daemon listens on the
D-Bus system bus for incoming requests.