An AuthInitialize implementation that obtains the user name and password as the
credentials from the given set of properties. If keep-extra-props property exits, it will copy
rest of the properties provided in getCredential props argument will also be copied as new
Initialize with the given set of security properties and return the credentials for the
peer/client as properties.
This method can modify the given set of properties. For example it may invoke external agents
or even interact with the user.
Normally it is expected that implementations will filter out security-* properties that
are needed for credentials and return only those.
server - the DistributedMember object of the server/group-coordinator to which
connection is being attempted
isPeer - true when this is invoked for peer initialization and false when invoked for
the credentials to be used for the given server
It needs to contain "security-username" and "security-password"
When using Integrated security, all members, peer/client will use the same credentials.
but we still need to use these params to support the old authenticator