Change how certificates are validated.

[StevenChisholm]

Currently, certificate validation in GEP requires a match on the certificate thumbprint. Can this be changed to match the public key. This would allow the expiration of a certificate to be updated without requiring every GEP party to re-exchange certificates.

[ritchiecarroll]

Guess that's possible, but better as an "option" in case Publisher actually wanted to require valid specific expiration date as part of the authentication process.