openssl_x509_parse() returns information about the supplied x509cert, including fields such as subject name, issuer name, purposes, valid from and valid to dates etc.
shortnames controls how the data is indexed in the
array - if shortnames is
TRUE (the default) then
fields will be indexed with the short name form, otherwise, the long name
form will be used - e.g.: CN is the shortname form of commonName.