RFC 1961 (rfc1961) - Page 2 of 9

GSS-API Authentication Method for SOCKS Version 5

RFC 1961          GSS-API Authentication for SOCKS V5          June 1996


   GSS-API V2 specification.

   The approach for use of GSS-API in SOCKS V5 is to authenticate the
   client and server by successfully establishing a GSS-API security
   context - such that the GSS-API encapsulates any negotiation protocol
   for mechanism selection, and the agreement of security service
   options.

   The GSS-API enables the context initiator to know what security
   services the target supports for the chosen mechanism.  The required
   level of protection is then agreed by negotiation.

   The GSS-API per-message protection calls are subsequently used to
   encapsulate any further TCP and UDP traffic between client and
   server.

3. GSS-API Security Context Establishment

3.1 Preparation

   Prior to use of GSS-API primitives, the client and server should be
   locally authenticated, and have established default GSS-API
   credentials.

   The client should call gss_import_name to obtain an internal
   representation of the server name.  For maximal portability the
   default name_type GSS_C_NULL_OID should be used to specify the
   default name space, and the input name_string should treated by the
   client's code as an opaque name-space specific input.

   For example, when using Kerberos V5 naming, the imported name may be
   of the form "SERVICE:socks@socks_server_hostname" where
   "socks_server_hostname" is the fully qualified host name of the
   server with all letters in lower case. Other mechanisms may, however,
   have different name forms, so the client should not make assumptions
   about the name syntax.

3.2 Client Context Establishment

   The client should then call gss_init_sec_context, typically passing:

         GSS_C_NO_CREDENTIAL into cred_handle to specify the default
         credential (for initiator usage),

         GSS_C_NULL_OID into mech_type to specify the default
         mechanism,





McMahon                     Standards Track