Simple exercise in authentication and encryption

The following operations are supported. For a formal definition, please review the Service Description.

• Logoff
  Logoff using GUID to identify session
• unencryptRequestTest
  Test unencryption, passing in GUID and results from PerformRequest method.
• PerformRequest
  Request using GUID as authentication key, encrypt incoming message using GUID and return.
• Logon
  Logon to service, would really lookup against auth API such as Windows/LDAP/mainframe RACF. Return GUID for subsequent calls. (Hard-coded logon is test/test)