ement functions for X.509 certificates that are 
used to authenticate connections to DataONE nodes over SSL.  The X.509 certificates are issued 
by a recognized Certificate Authority, typically CILogon, and include fields that provide 
information about the authenticated party, including the distinguished name of the subject, the 
dates of validity of the certificate, and other information needed for authorization decisions.  
Certificate validity is determined by examining the validity of the certificate s