When negotiated by SPNEGO, NEGOEX uses the concepts developed in the GSS-API specification [RFC2743]. Therefore, the prerequisites/preconditions defined in [MS-SPNG] section 1.5 are applicable to NEGOEX.
Because NEGOEX relies on other security protocols that perform authentication, those protocols have to be available for it to operate. The set of available protocols is implementation specific and is set at the time of installation<1>.
The message signing and verification in NEGOEX is based on [RFC3961], which is used as a generic framework. A security mechanism has to support [RFC3961] in order to be negotiated by NEGOEX.