I have an exam to give on 15th March 4:30 - 7:00 am GMT , i will give the question at that particular time but to give you an idea i have attached the sample paper

/* -*- mode: c; indent-tabs-mode: nil -*- */
/*
* Copyright 1993 by OpenVision Technologies, Inc.
*
* Permission to use, copy, modify, distribute, and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appears in all copies and
* that both that copyright notice and this permission notice appear in
* supporting documentation, and that the name of OpenVision not be used
* in advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. OpenVision makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef _GSSAPI_H_
#define _GSSAPI_H_
/*
* Determine platform-dependent configuration.
*/
#if defined(__MACH__) && defined(__APPLE__)
# include
# if TARGET_RT_MAC_CFM
# error "Use KfM 4.0 SDK headers for CFM compilation."
# endif
#endif
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
#if defined(TARGET_OS_MAC) && TARGET_OS_MAC
# pragma pack(push,2)
#endif
#if defined(_MSDOS) || defined(_WIN32)
#include
#endif
#ifndef KRB5_CALLCONV
#define KRB5_CALLCONV
#define KRB5_CALLCONV_C
#endif
#include
/*
* First, include stddef.h to get size_t defined.
*/
#include
/*
* POSIX says that sys/types.h is where size_t is defined.
*/
#include
/*
* $Id$
*/
/*
* First, define the three platform-dependent pointer types.
*/
struct gss_name_struct;
typedef struct gss_name_struct * gss_name_t;
struct gss_cred_id_struct;
typedef struct gss_cred_id_struct * gss_cred_id_t;
struct gss_ctx_id_struct;
typedef struct gss_ctx_id_struct * gss_ctx_id_t;
/*
* The following type must be defined as the smallest natural unsigned integer
* supported by the platform that has at least 32 bits of precision.
*/
typedef uint32_t gss_uint32;
typedef int32_t gss_int32;
#ifdef OM_STRING
/*
* We have included the xom.h header file. Use the definition for
* OM_object identifier.
*/
typedef OM_object_identifier gss_OID_desc, *gss_OID;
#else /* OM_STRING */
/*
* We can't use X/Open definitions, so roll our own.
*/
typedef gss_uint32 OM_uint32;
typedef struct gss_OID_desc_struct {
OM_uint32 length;
void *elements;
} gss_OID_desc, *gss_OID;
#endif /* OM_STRING */
typedef struct gss_OID_set_desc_struct {
size_t count;
gss_OID elements;
} gss_OID_set_desc, *gss_OID_set;
typedef struct gss_buffer_desc_struct {
size_t length;
void *value;
} gss_buffer_desc, *gss_buffer_t;
typedef struct gss_channel_bindings_struct {
OM_uint32 initiator_addrtype;
gss_buffer_desc initiator_address;
OM_uint32 acceptor_addrtype;
gss_buffer_desc acceptor_address;
gss_buffer_desc application_data;
} *gss_channel_bindings_t;
/*
* For now, define a QOP-type as an OM_uint32 (pending resolution of ongoing
* discussions).
*/
typedef OM_uint32 gss_qop_t;
typedef int gss_cred_usage_t;
/*
* Flag bits for context-level services.
*/
#define GSS_C_DELEG_FLAG 1
#define GSS_C_MUTUAL_FLAG 2
#define GSS_C_REPLAY_FLAG 4
#define GSS_C_SEQUENCE_FLAG 8
#define GSS_C_CONF_FLAG 16
#define GSS_C_INTEG_FLAG 32
#define GSS_C_ANON_FLAG 64
#define GSS_C_PROT_READY_FLAG 128
#define GSS_C_TRANS_FLAG 256
#define GSS_C_DELEG_POLICY_FLAG 32768
/*
* Credential usage options
*/
#define GSS_C_BOTH 0
#define GSS_C_INITIATE 1
#define GSS_C_ACCEPT 2
/*
* Status code types for gss_display_status
*/
#define GSS_C_GSS_CODE 1
#define GSS_C_MECH_CODE 2
/*
* The constant definitions for channel-bindings address families
*/
#define GSS_C_AF_UNSPEC 0
#define GSS_C_AF_LOCAL 1
#define GSS_C_AF_INET 2
#define GSS_C_AF_IMPLINK 3
#define GSS_C_AF_PUP 4
#define GSS_C_AF_CHAOS 5
#define GSS_C_AF_NS 6
#define GSS_C_AF_NBS 7
#define GSS_C_AF_ECMA 8
#define GSS_C_AF_DATAKIT 9
#define GSS_C_AF_CCITT 10
#define GSS_C_AF_SNA 11
#define GSS_C_AF_DECnet 12
#define GSS_C_AF_DLI 13
#define GSS_C_AF_LAT 14
#define GSS_C_AF_HYLINK 15
#define GSS_C_AF_APPLETALK 16
#define GSS_C_AF_BSC 17
#define GSS_C_AF_DSS 18
#define GSS_C_AF_OSI 19
#define GSS_C_AF_NETBIOS 20
#define GSS_C_AF_X25 21
#define GSS_C_AF_NULLADDR 255
/*
* Various Null values.
*/
#define GSS_C_NO_NAME ((gss_name_t) 0)
#define GSS_C_NO_BUFFER ((gss_buffer_t) 0)
#define GSS_C_NO_OID ((gss_OID) 0)
#define GSS_C_NO_OID_SET ((gss_OID_set) 0)
#define GSS_C_NO_CONTEXT ((gss_ctx_id_t) 0)
#define GSS_C_NO_CREDENTIAL ((gss_cred_id_t) 0)
#define GSS_C_NO_CHANNEL_BINDINGS ((gss_channel_bindings_t) 0)
#define GSS_C_EMPTY_BUFFER {0, NULL}
/*
* Some alternate names for a couple of the above values. These are defined
* for V1 compatibility.
*/
#define GSS_C_NULL_OID GSS_C_NO_OID
#define GSS_C_NULL_OID_SET GSS_C_NO_OID_SET
/*
* Define the default Quality of Protection for per-message services. Note
* that an implementation that offers multiple levels of QOP may either reserve
* a value (for example zero, as assumed here) to mean "default protection", or
* alternatively may simply equate GSS_C_QOP_DEFAULT to a specific explicit
* QOP value. However a value of 0 should always be interpreted by a GSSAPI
* implementation as a request for the default protection level.
*/
#define GSS_C_QOP_DEFAULT 0
/*
* Expiration time of 2^32-1 seconds means infinite lifetime for a
* credential or security context
*/
#define GSS_C_INDEFINITE ((OM_uint32) 0xfffffffful)
/* Major status codes */
#define GSS_S_COMPLETE 0
/*
* Some "helper" definitions to make the status code macros obvious.
*/
#define GSS_C_CALLING_ERROR_OFFSET 24
#define GSS_C_ROUTINE_ERROR_OFFSET 16
#define GSS_C_SUPPLEMENTARY_OFFSET 0
#define GSS_C_CALLING_ERROR_MASK ((OM_uint32) 0377ul)
#define GSS_C_ROUTINE_ERROR_MASK ((OM_uint32) 0377ul)
#define GSS_C_SUPPLEMENTARY_MASK ((OM_uint32) 0177777ul)
/*
* The macros that test status codes for error conditions. Note that the
* GSS_ERROR() macro has changed slightly from the V1 GSSAPI so that it now
* evaluates its argument only once.
*/
#define GSS_CALLING_ERROR(x) \
((x) & (GSS_C_CALLING_ERROR_MASK << GSS_C_CALLING_ERROR_OFFSET))
#define GSS_ROUTINE_ERROR(x) \
((x) & (GSS_C_ROUTINE_ERROR_MASK << GSS_C_ROUTINE_ERROR_OFFSET))
#define GSS_SUPPLEMENTARY_INFO(x) \
((x) & (GSS_C_SUPPLEMENTARY_MASK << GSS_C_SUPPLEMENTARY_OFFSET))
#define GSS_ERROR(x) \
((x) & ((GSS_C_CALLING_ERROR_MASK << GSS_C_CALLING_ERROR_OFFSET) | \
(GSS_C_ROUTINE_ERROR_MASK << GSS_C_ROUTINE_ERROR_OFFSET)))
/*
* Now the actual status code definitions
*/
/*
* Calling errors:
*/
#define GSS_S_CALL_INACCESSIBLE_READ \
(((OM_uint32) 1ul) << GSS_C_CALLING_ERROR_OFFSET)
#define GSS_S_CALL_INACCESSIBLE_WRITE \
(((OM_uint32) 2ul) << GSS_C_CALLING_ERROR_OFFSET)
#define GSS_S_CALL_BAD_STRUCTURE \
(((OM_uint32) 3ul) << GSS_C_CALLING_ERROR_OFFSET)
/*
* Routine errors:
*/
#define GSS_S_BAD_MECH (((OM_uint32) 1ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_NAME (((OM_uint32) 2ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_NAMETYPE (((OM_uint32) 3ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_BINDINGS (((OM_uint32) 4ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_STATUS (((OM_uint32) 5ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_SIG (((OM_uint32) 6ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_MIC GSS_S_BAD_SIG
#define GSS_S_NO_CRED (((OM_uint32) 7ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_NO_CONTEXT (((OM_uint32) 8ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_DEFECTIVE_TOKEN (((OM_uint32) 9ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_DEFECTIVE_CREDENTIAL \
(((OM_uint32) 10ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_CREDENTIALS_EXPIRED \
(((OM_uint32) 11ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_CONTEXT_EXPIRED \
(((OM_uint32) 12ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_FAILURE (((OM_uint32) 13ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_QOP (((OM_uint32) 14ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_UNAUTHORIZED (((OM_uint32) 15ul) << GSS_C_ROUTINE_ERROR_OFFSET)
#define...