This routine provides a way to pass an asynchronous token
to the security service. Most context-level tokens are emitted
and processed synchronously by gss_init_sec_context and gss_accept_sec_context,
and the application is informed as to whether further tokens are
expected by the GSS_C_CONTINUE_NEEDED status return. Occasionally,
a mechanism may need to emit a context-level token at a point when
the peer entity is not expecting a token. For example, the initiator's
final call to gss_init_sec_context may
emit a token and return a status of GSS_S_COMPLETE, but the acceptor's
call to gss_accept_sec_context may fail.
The acceptor's mechanism may wish to send a token containing an
error indication to the initiator, but the initiator is not expecting
a token at this point, believing that the context is fully established.
The gss_process_context_token routine
provides a way to pass such a token to the mechanism at any time.