path: root/crypto/heimdal/doc/standardisation/draft-ietf-cat-gssv2-cbind-04.txt

   Internet draft                                                    J.Wray
   IETF Common Authentication Technology WG   Digital Equipment Corporation
   <draft-ietf-cat-gssv2-cbind-04.txt>                           March 1997



             Generic Security Service API Version 2 : C-bindings


   1. STATUS OF THIS MEMO

   This document is an Internet Draft.  Internet Drafts are working
   documents of the Internet Engineering Task Force (IETF), its Areas, and
   its Working Groups.  Note that other groups may also distribute working
   documents as Internet Drafts.  Internet Drafts are draft documents valid
   for a maximum of six months. Internet Drafts may be updated, replaced,
   or obsoleted by other documents at any time.  It is not appropriate to
   use Internet Drafts as reference material or to cite them other than as
   a "working draft" or "work in progress." Please check the I-D abstract
   listing contained in each Internet Draft directory to learn the current
   status of this or any other Internet Draft.

   Comments on this document should be sent to "cat-ietf@MIT.EDU", the IETF
   Common Authentication Technology WG discussion list.


   2. ABSTRACT

   This draft document specifies C language bindings for Version 2 of the
   Generic Security Service Application Program Interface (GSSAPI), which
   is described at a language-independent conceptual level in other drafts
   [GSSAPI]. It revises RFC-1509, making specific incremental changes in
   response to implementation experience and liaison requests.  It is
   intended, therefore, that this draft or a successor version thereof will
   become the basis for subsequent progression of the GSS-API specification
   on the standards track.

   The Generic Security Service Application Programming Interface provides
   security services to its callers, and is intended for implementation
   atop a variety of underlying cryptographic mechanisms.  Typically,
   GSSAPI callers will be application protocols into which security
   enhancements are integrated through invocation of services provided by
   the GSSAPI. The GSSAPI allows a caller application to authenticate a
   principal identity associated with a peer application, to delegate
   rights to a peer, and to apply security services such as confidentiality
   and integrity on a per-message basis.








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   3. INTRODUCTION

   The Generic Security Service Application Programming Interface [GSSAPI]
   provides security services to calling applications.  It allows a
   communicating application to authenticate the user associated with
   another application, to delegate rights to another application, and to
   apply security services such as confidentiality and integrity on a per-
   message basis.

   There are four stages to using the GSSAPI:

     (a) The application acquires a set of credentials with which it may
         prove its identity to other processes.  The application's
         credentials vouch for its global identity, which may or may not be
         related to any local username under which it may be running.

     (b) A pair of communicating applications establish a joint security
         context using their credentials.  The security context is a pair
         of GSSAPI data structures that contain shared state information,
         which is required in order that per-message security services may
         be provided.  Examples of state that might be shared between
         applications as part of a security context are cryptographic keys,
         and message sequence numbers.  As part of the establishment of a
         security context, the context initiator is authenticated to the
         responder, and may require that the responder is authenticated in
         turn.  The initiator may optionally give the responder the right
         to initiate further security contexts, acting as an agent or
         delegate of the initiator.  This transfer of rights is termed
         delegation, and is achieved by creating a set of credentials,
         similar to those used by the initiating application, but which may
         be used by the responder.

         To establish and maintain the shared information that makes up the
         security context, certain GSSAPI calls will return a token data
         structure, which is a cryptographically protected opaque data
         type.  The caller of such a GSSAPI routine is responsible for
         transferring the token to the peer application, encapsulated if
         necessary in an application-application protocol.  On receipt of
         such a token, the peer application should pass it to a
         corresponding GSSAPI routine which will decode the token and
         extract the information, updating the security context state
         information accordingly.

     (c) Per-message services are invoked to apply either:

           (i) integrity and data origin authentication, or

          (ii) confidentiality, integrity and data origin authentication

         to application data, which are treated by GSSAPI as arbitrary
         octet-strings.  An application transmitting a message that it



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         wishes to protect will call the appropriate GSSAPI routine
         (gss_get_mic or gss_wrap) to apply protection, specifying the
         appropriate security context, and send the resulting token to the
         receiving application.  The receiver will pass the received token
         (and, in the case of data protected by gss_get_mic, the
         accompanying message-data) to the corresponding decoding routine
         (gss_verify_mic or gss_unwrap) to remove the protection and
         validate the data.

     (d) At the completion of a communications session (which may extend
         across several transport connections), each application calls a
         GSSAPI routine to delete the security context.  Multiple contexts
         may also be used (either successively or simultaneously) within a
         single communications association, at the option of the
         applications.


   4. GSSAPI ROUTINES

   This section lists the routines that make up the GSSAPI, and offers a
   brief description of the purpose of each routine.  Detailed descriptions
   of each routine are listed in alphabetical order in section 7.

   Table 4-1  GSSAPI Credential-management Routines

         ROUTINE            SECTION        FUNCTION

     gss_acquire_cred          7.2  Assume a global identity;
                                    Obtain a GSSAPI credential
                                    handle for pre-existing
                                    credentials.

     gss_add_cred              7.3  Construct credentials
                                    incrementally

     gss_inquire_cred          7.21 Obtain information about
                                    a credential.

     gss_inquire_cred_by_mech  7.22 Obtain per-mechanism information
                                    about a credential.

     gss_release_cred          7.27 Discard a credential handle.












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   Table 4-2  GSSAPI Context-level Routines

         ROUTINE            SECTION        FUNCTION

     gss_init_sec_context      7.19 Initiate a security context
                                    with a peer application


     gss_accept_sec_context    7.1  Accept a security context
                                    initiated by a peer
                                    application

     gss_delete_sec_context    7.9  Discard a security context

     gss_process_context_token 7.25 Process a token on a security
                                    context from a peer
                                    application

     gss_context_time          7.7  Determine for how long a
                                    context will remain valid

     gss_inquire_context       7.20 Obtain information about a
                                    security context

     gss_wrap_size_limit       7.33 Determine token-size limit for
                                    gss_wrap on a context

     gss_export_sec_context    7.14 Transfer a security context to
                                    another process

     gss_import_sec_context    7.17 Import a transferred context




   Table 4-3  GSSAPI Per-message Routines

         ROUTINE            SECTION        FUNCTION

     gss_get_mic               7.15 Calculate a cryptographic
                                    Message Integrity Code (MIC)
                                    for a message; integrity service

     gss_verify_mic            7.32 Check a MIC against a message;
                                    verify integrity of a received
                                    message

     gss_wrap                  7.36 Attach a MIC to a message, and
                                    optionally encrypt the message
                                    content; confidentiality service




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     gss_unwrap                7.31 Verify a message with attached
                                    MIC, and decrypt message
                                    content if necessary.




   Table 4-4  GSSAPI Name manipulation Routines

         ROUTINE              SECTION        FUNCTION

     gss_import_name            7.16 Convert a contiguous string name
                                     to internal-form

     gss_display_name           7.10 Convert internal-form name
                                     to text

     gss_compare_name           7.6  Compare two internal-form names

     gss_release_name           7.28 Discard an internal-form name

     gss_inquire_names_for_mech 7.24 List the name-types supported
                                     by a specified mechanism

     gss_inquire_mechs_for_name 7.23 List mechanisms that support
                                     a given nametype

     gss_canonicalize_name      7.5  Convert an internal name to
                                     an MN.

     gss_export_name            7.13 Convert an MN to export form

     gss_duplicate_name         7.12 Create a copy of an internal name




   Table 4-5  GSSAPI Miscellaneous Routines

         ROUTINE              SECTION        FUNCTION

     gss_display_status         7.11 Convert a GSSAPI status code
                                     to text

     gss_indicate_mechs         7.18 Determine available underlying
                                     authentication mechanisms

     gss_release_buffer         7.26 Discard a buffer

     gss_release_oid_set        7.29 Discard a set of object
                                     identifiers



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     gss_create_empty_oid_set   7.8  Create a set containing no
                                     object identifiers

     gss_add_oid_set_member     7.4  Add an object identifier to
                                     a set

     gss_test_oid_set_member    7.30 Determines whether an object
                                     identifier is a member of a set





   Individual GSSAPI implementations may augment these routines by
   providing additional mechanism-specific routines if required
   functionality is not available from the generic forms.  Applications are
   encouraged to use the generic routines wherever possible on portability
   grounds.


   5. DATA TYPES AND CALLING CONVENTIONS

   The following conventions are used by the GSSAPI C-language bindings:

   5.1.  Integer types

   GSSAPI uses the following integer data type:

        OM_uint32      32-bit unsigned integer

   Where guaranteed minimum bit-count is important, this portable data type
   is used by the GSSAPI routine definitions.  Individual GSSAPI
   implementations will include appropriate typedef definitions to map this
   type onto a built-in data type.  If the platform supports the X/Open
   xom.h header file, the OM_uint32 definition contained therein should be
   used; the GSSAPI header file in Appendix A contains logic that will
   detect the prior inclusion of xom.h, and will not attempt to re-declare
   OM_uint32.  If the X/Open header file is not available on the platform,
   the GSSAPI implementation should use the smallest natural unsigned
   integer type that provides at least 32 bits of precision.

   5.2.  String and similar data

   Many of the GSSAPI routines take arguments and return values that
   describe contiguous octet-strings.  All such data is passed between the
   GSSAPI and the caller using the gss_buffer_t data type.  This data type
   is a pointer to a buffer descriptor, which consists of a length field
   that contains the total number of bytes in the datum, and a value field
   which contains a pointer to the actual datum:





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        typedef struct gss_buffer_desc_struct {
           size_t  length;
           void    *value;
        } gss_buffer_desc, *gss_buffer_t;

   Storage for data returned to the application by a GSSAPI routine using
   the gss_buffer_t conventions is allocated by the GSSAPI routine.  The
   application may free this storage by invoking the gss_release_buffer
   routine.  Allocation of the gss_buffer_desc object is always the
   responsibility of the application;  unused gss_buffer_desc objects may
   be initialized to the value GSS_C_EMPTY_BUFFER.

   5.2.1.  Opaque data types

   Certain multiple-word data items are considered opaque data types at the
   GSSAPI, because their internal structure has no significance either to
   the GSSAPI or to the caller.  Examples of such opaque data types are the
   input_token parameter to gss_init_sec_context (which is opaque to the
   caller), and the input_message parameter to gss_wrap (which is opaque to
   the GSSAPI).  Opaque data is passed between the GSSAPI and the
   application using the gss_buffer_t datatype.

   5.2.2.  Character strings

   Certain multiple-word data items may be regarded as simple ISO Latin-1
   character strings.  Examples are the printable strings passed to
   gss_import_name via the input_name_buffer parameter. Some GSSAPI
   routines also return character strings.  All such character strings are
   passed between the application and the GSSAPI implementation using the
   gss_buffer_t datatype, which is a pointer to a gss_buffer_desc object.

   When a gss_buffer_desc object describes a printable string, the length
   field of the gss_buffer_desc should only count printable characters
   within the string.  In particular, a trailing NUL character should NOT
   be included in the length count, nor should either the GSSAPI
   implementation or the application assume the presence of an uncounted
   trailing NUL.

   5.3.  Object Identifiers

   Certain GSSAPI procedures take parameters of the type gss_OID, or Object
   identifier.  This is a type containing ISO-defined tree-structured
   values, and is used by the GSSAPI caller to select an underlying
   security mechanism and to specify namespaces.  A value of type gss_OID
   has the following structure:

        typedef struct gss_OID_desc_struct {
           OM_uint32 length;
           void      *elements;
        } gss_OID_desc, *gss_OID;




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   The elements field of this structure points to the first byte of an
   octet string containing the ASN.1 BER encoding of the value portion of
   the normal BER TLV encoding of the gss_OID.  The length field contains
   the number of bytes in this value.  For example, the gss_OID value
   corresponding to {iso(1) identified-organization(3) icd-ecma(12)
   member-company(2) dec(1011) cryptoAlgorithms(7) DASS(5)}, meaning the
   DASS X.509 authentication mechanism, has a length field of 7 and an
   elements field pointing to seven octets containing the following octal
   values: 53,14,2,207,163,7,5. GSSAPI implementations should provide
   constant gss_OID values to allow applications to request any supported
   mechanism, although applications are encouraged on portability grounds
   to accept the default mechanism.  gss_OID values should also be provided
   to allow applications to specify particular name types (see section
   5.10).  Applications should treat gss_OID_desc values returned by GSSAPI
   routines as read-only.  In particular, the application should not
   attempt to deallocate them with free().  The gss_OID_desc datatype is
   equivalent to the X/Open OM_object_identifier datatype[XOM].

   5.4.  Object Identifier Sets

   Certain GSSAPI procedures take parameters of the type gss_OID_set.  This
   type represents one or more object identifiers (section 5.3).  A
   gss_OID_set object has the following structure:

        typedef struct gss_OID_set_desc_struct {
           size_t       count;
           gss_OID   elements;
        } gss_OID_set_desc, *gss_OID_set;

   The count field contains the number of OIDs within the set.  The
   elements field is a pointer to an array of gss_OID_desc objects, each of
   which describes a single OID.  gss_OID_set values are used to name the
   available mechanisms supported by the GSSAPI, to request the use of
   specific mechanisms, and to indicate which mechanisms a given credential
   supports.

   All OID sets returned to the application by GSSAPI are dynamic objects
   (the gss_OID_set_desc, the "elements" array of the set, and the
   "elements" array of each member OID are all dynamically allocated), and
   this storage must be deallocated by the application using the
   gss_release_oid_set() routine.


   5.5.  Credentials

   A credential handle is a caller-opaque atomic datum that identifies a
   GSSAPI credential data structure.  It is represented by the caller-
   opaque type gss_cred_id_t, which should be implemented as a pointer or
   arithmetic type.  If a pointer implementation is chosen, care must be
   taken to ensure that two gss_cred_id_t values may be compared with the
   == operator.



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   GSSAPI credentials can contain mechanism-specific principal
   authentication data for multiple mechanisms.  A GSSAPI credential is
   composed of a set of credential-elements, each of which is applicable to
   a single mechanism.  A credential may contain at most one credential-
   element for each supported mechanism. A credential-element identifies
   the data needed by a single mechanism to authenticate a single
   principal, and conceptually contains two credential-references that
   describing the actual mechanism-specific authentication data, one to be
   used by GSSAPI for initiating contexts,  and one to be used for
   accepting contexts.  For mechanisms that do not distinguish between
   acceptor and initiator credentials, both references would point to the
   same underlying mechanism-specific authentication data.

   Credentials describe a set of mechanism-specific principals, and give
   their holder the ability to act as any of those principals.  All
   principal identities asserted by a single GSSAPI credential should
   belong to the same entity, although enforcement of this property is an
   implementation-specific matter.  The GSSAPI does not make the actual
   credentials available to applications; instead a credential handle is
   used to identify a particular credential, held internally by GSSAPI.
   The combination of GSSAPI credential handle and mechanism identifies the
   principal whose identity will be asserted by the credential when used
   with that mechanism.

   The gss_init_sec_context and gss_accept_sec_context routines allow the
   value GSS_C_NO_CREDENTIAL to be specified as their credential handle
   parameter.  This special credential-handle indicates a desire by the
   application to act as a default principal.  While individual GSSAPI
   implementations are free to determine such default behavior as
   appropriate to the mechanism, the following default behavior by these
   routines is recommended for portability:

     (a) gss_init_sec_context

           (i) If there is only a single principal capable of initiating
               security contexts for the chosen mechanism that the
               application is authorized to act on behalf of, then that
               principal shall be used, otherwise

          (ii) If the platform maintains a concept of a default network-
               identity for the chosen mechanism, and if the application is
               authorized to act on behalf of that identity for the purpose
               of initiating security contexts, then the principal
               corresponding to that identity shall be used, otherwise

         (iii) If the platform maintains a concept of a default local
               identity, and provides a means to map local identities into
               network-identities for the chosen mechanism, and if the
               application is authorized to act on behalf of the network-
               identity image of the default local identity for the purpose
               of initiating security contexts using the chosen mechanism,



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               then the principal corresponding to that identity shall be
               used, otherwise

          (iv) A user-configurable default identity should be used.

     (b) gss_accept_sec_context

           (i) If there is only a single authorized principal identity
               capable of accepting security contexts for the chosen
               mechanism, then that principal shall be used, otherwise

          (ii) If the mechanism can determine the identity of the target
               principal by examining the context-establishment token, and
               if the accepting application is authorized to act as that
               principal for the purpose of accepting security contexts
               using the chosen mechanism, then that principal identity
               shall be used, otherwise

         (iii) If the mechanism supports context acceptance by any
               principal, and if mutual authentication was not requested,
               any principal that the application is authorized to accept
               security contexts under using the chosen mechanism may be
               used, otherwise

          (iv) A user-configurable default identity shall be used.

   The purpose of the above rules is to allow security contexts to be
   established by both initiator and acceptor using the default behavior
   wherever possible.  Applications requesting default behavior are likely
   to be more portable across mechanisms and platforms than ones that use
   gss_acquire_cred to request a specific identity.

   5.6.  Contexts

   The gss_ctx_id_t data type contains a caller-opaque atomic value that
   identifies one end of a GSSAPI security context.  It should be
   implemented as a pointer or arithmetic type.  If a pointer type is
   chosen, care should be taken to ensure that two gss_ctx_id_t values may
   be compared with the == operator.

   The security context holds state information about each end of a peer
   communication, including cryptographic state information.

   5.7.  Authentication tokens

   A token is a caller-opaque type that GSSAPI uses to maintain
   synchronization between the context data structures at each end of a
   GSSAPI security context.  The token is a cryptographically protected
   octet-string, generated by the underlying mechanism at one end of a
   GSSAPI security context for use by the peer mechanism at the other end.
   Encapsulation (if required) and transfer of the token are the



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   responsibility of the peer applications.  A token is passed between the
   GSSAPI and the application using the gss_buffer_t conventions.

   5.8.  Interprocess tokens

   Certain GSSAPI routines are intended to transfer data between processes
   in multi-process programs.  These routines use a caller-opaque octet-
   string, generated by the GSSAPI in one process for use by the GSSAPI in
   another process.  The calling application is responsible for
   transferring such tokens between processes in an OS-specific manner.
   Note that, while GSSAPI implementors are encouraged to avoid placing
   sensitive information within interprocess tokens, or to
   cryptographically protect them, many implementations will be unable to
   avoid placing key material or other sensitive data within them.  It is
   the application's responsibility to ensure that interprocess tokens are
   protected in transit, and transferred only to processes that are
   trustworthy. An interprocess token is passed between the GSSAPI and the
   application using the gss_buffer_t conventions.

   5.9.  Status values

   One or more status codes are returned by each GSSAPI routine.  Two
   distinct sorts of status codes are returned.  These are termed GSS
   status codes and Mechanism status codes.

   5.9.1.  GSS status codes

   GSSAPI routines return GSS status codes as their OM_uint32 function
   value.  These codes indicate errors that are independent of the
   underlying mechanism(s) used to provide the security service.  The
   errors that can be indicated via a GSS status code are either generic
   API routine errors (errors that are defined in the GSS-API
   specification) or calling errors (errors that are specific to these
   language bindings).

   A GSS status code can indicate a single fatal generic API error from the
   routine and a single calling error.  In addition, supplementary status
   information may be indicated via the setting of bits in the
   supplementary info field of a GSS status code.

   These errors are encoded into the 32-bit GSS status code as follows:

       MSB                                                        LSB
       |------------------------------------------------------------|
       | Calling Error | Routine Error  |    Supplementary Info     |
       |------------------------------------------------------------|
    Bit 31           24 23            16 15                        0


   Hence if a GSS-API routine returns a GSS status code whose upper 16 bits
   contain a non-zero value, the call failed.  If the calling error field



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   is non-zero, the invoking application's call of the routine was
   erroneous.  Calling errors are defined in table 5-1.  If the routine
   error field is non-zero, the routine failed for one of the routine-
   specific reasons listed below in table 5-2.  Whether or not the upper 16
   bits indicate a failure or a success, the routine may indicate
   additional information by setting bits in the supplementary info field
   of the status code.  The meaning of individual bits is listed below in
   table 5-3.

   Table 5-1  Calling Errors

         Name                    Value in        Meaning
                                   Field
    GSS_S_CALL_INACCESSIBLE_READ     1           A required input
                                                 parameter could
                                                 not be read.
    GSS_S_CALL_INACCESSIBLE_WRITE    2           A required output
                                                 parameter could
                                                 not be written.
    GSS_S_CALL_BAD_STRUCTURE         3           A parameter was
                                                 malformed




   Table 5-2  Routine Errors

          Name             Value in       Meaning
                            Field

    GSS_S_BAD_MECH             1      An unsupported mechanism was
                                      requested
    GSS_S_BAD_NAME             2      An invalid name was supplied
    GSS_S_BAD_NAMETYPE         3      A supplied name was of an
                                      unsupported type
    GSS_S_BAD_BINDINGS         4      Incorrect channel bindings
                                      were supplied
    GSS_S_BAD_STATUS           5      An invalid status code was
                                      supplied
    GSS_S_BAD_SIG              6      A token had an invalid
    GSS_S_BAD_MIC                     MIC
    GSS_S_NO_CRED              7      No credentials were supplied,
                                      or the credentials were
                                      unavailable or inaccessible.
    GSS_S_NO_CONTEXT           8      No context has been
                                      established
    GSS_S_DEFECTIVE_TOKEN      9      A token was invalid
    GSS_S_DEFECTIVE_CREDENTIAL 10     A credential was invalid
    GSS_S_CREDENTIALS_EXPIRED  11     The referenced credentials
                                      have expired




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    GSS_S_CONTEXT_EXPIRED      12     The context has expired
    GSS_S_FAILURE              13     Miscellaneous failure
                                      (see text)
    GSS_S_BAD_QOP              14     The quality-of-protection
                                      requested could not be
                                      provide
    GSS_S_UNAUTHORIZED         15     The operation is forbidden by
                                      local security policy
    GSS_S_UNAVAILABLE          16     The operation or option is not
                                      available
    GSS_S_DUPLICATE_ELEMENT    17     The requested credential element
                                      already exists
    GSS_S_NAME_NOT_MN          18     The provided name was not a
                                      mechanism name.





   Table 5-3  Supplementary Status Bits

    Name                Bit Number         Meaning
    GSS_S_CONTINUE_NEEDED   0 (LSB)  The routine must be called
                                     again to complete its function.
                                     See routine documentation for
                                     detailed description.
    GSS_S_DUPLICATE_TOKEN   1        The token was a duplicate of
                                     an earlier token
    GSS_S_OLD_TOKEN         2        The token's validity period
                                     has expired
    GSS_S_UNSEQ_TOKEN       3        A later token has already been
                                     processed
    GSS_S_GAP_TOKEN         4        An expected per-message token
                                     was not received


   The routine documentation also uses the name GSS_S_COMPLETE, which is a
   zero value, to indicate an absence of any API errors or supplementary
   information bits.

   All GSS_S_xxx symbols equate to complete OM_uint32 status codes, rather
   than to bitfield values.  For example, the actual value of the symbol
   GSS_S_BAD_NAMETYPE (value 3 in the routine error field) is 3 << 16.

   The macros GSS_CALLING_ERROR(), GSS_ROUTINE_ERROR() and
   GSS_SUPPLEMENTARY_INFO() are provided, each of which takes a GSS status
   code and removes all but the relevant field.  For example, the value
   obtained by applying GSS_ROUTINE_ERROR to a status code removes the
   calling errors and supplementary info fields, leaving only the routine
   errors field.  The values delivered by these macros may be directly
   compared with a GSS_S_xxx symbol of the appropriate type.  The macro



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   GSS_ERROR() is also provided, which when applied to a GSS status code
   returns a non-zero value if the status code indicated a calling or
   routine error, and a zero value otherwise.  All macros defined by GSS-
   API evaluate their argument(s) exactly once.

   A GSS-API implementation may choose to signal calling errors in a
   platform-specific manner instead of, or in addition to the routine
   value;  routine errors and supplementary info should be returned via
   routine status values only.

   5.9.2.  Mechanism-specific status codes

   GSS-API routines return a minor_status parameter, which is used to
   indicate specialized errors from the underlying security mechanism.
   This parameter may contain a single mechanism-specific error, indicated
   by a OM_uint32 value.

   The minor_status parameter will always be set by a GSS-API routine, even
   if it returns a calling error or one of the generic API errors indicated
   above as fatal, although most other output parameters may remain unset
   in such cases.  However, output parameters that are expected to return
   pointers to storage allocated by a routine must always be set by the
   routine, even in the event of an error, although in such cases the GSS-
   API routine may elect to set the returned parameter value to NULL to
   indicate that no storage was actually allocated.  Any length field
   associated with such pointers (as in a gss_buffer_desc structure) should
   also be set to zero in such cases.

   The GSS status code GSS_S_FAILURE is used to indicate that the
   underlying mechanism detected an error for which no specific GSS status
   code is defined.  The mechanism status code will provide more details
   about the error.

   5.10.  Names

   A name is used to identify a person or entity.  GSS-API authenticates
   the relationship between a name and the entity claiming the name.

   Since different authentication mechanisms may employ different
   namespaces for identifying their principals, GSSAPI's naming support is
   necessarily complex in multi-mechanism environments (or even in some
   single-mechanism environments where the underlying mechanism supports
   multiple namespaces).

   Two distinct representations are defined for names:

     (a) An internal form.  This is the GSSAPI "native" format for names,
         represented by the implementation-specific gss_name_t type.  It is
         opaque to GSSAPI callers.  A single gss_name_t object may contain
         multiple names from different namespaces, but all names should
         refer to the same entity.  An example of such an internal name



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         would be the name returned from a call to the gss_inquire_cred
         routine, when applied to a credential containing credential
         elements for multiple authentication mechanisms employing
         different namespaces.  This gss_name_t object will contain a
         distinct name for the entity for each authentication mechanism.

         For GSSAPI implementations supporting multiple namespaces, objects
         of type gss_name_t must contain sufficient information to
         determine the namespace to which each primitive name belongs.

     (b) Mechanism-specific contiguous octet-string forms.  A format
         capable of containing a single name (from a single namespace).
         Contiguous string names are always accompanied by an object
         identifier specifying the namespace to which the name belongs, and
         their format is dependent on the authentication mechanism that
         employs the name.  Many, but not all, contiguous string names will
         be printable, and may therefore be used by GSSAPI applications for
         communication with their users.

   Routines (gss_import_name and gss_display_name) are provided to convert
   names between contiguous string representations and the internal
   gss_name_t type.  gss_import_name may support multiple syntaxes for each
   supported namespace, allowing users the freedom to choose a preferred
   name representation.  gss_display_name should use an implementation-
   chosen printable syntax for each supported name-type.

   If an application calls gss_display_name(), passing the internal name
   resulting from a call to gss_import_name(), there is no guarantee the
   the resulting contiguous string name will be the same as the original
   imported string name.  Nor do name-space identifiers necessarily survive
   unchanged after a journey through the internal name-form.  An example of
   this might be a mechanism that authenticates X.500 names, but provides
   an algorithmic mapping of Internet DNS names into X.500.  That
   mechanism's implementation of gss_import_name() might, when presented
   with a DNS name, generate an internal name that contained both the
   original DNS name and the equivalent X.500 name. Alternatively, it might
   only store the X.500 name.  In the latter case, gss_display_name() would
   most likely generate a printable X.500 name, rather than the original
   DNS name.

   The process of authentication delivers to the context acceptor an
   internal name.  Since this name has been authenticated by a single
   mechanism, it contains only a single name (even if the internal name
   presented by the context initiator to gss_init_sec_context had multiple
   components).  Such names are termed internal mechanism names, or "MN"s
   and the names emitted by gss_accept_sec_context() are always of this
   type.  Since some applications may require MNs without wanting to incur
   the overhead of an authentication operation, a second function,
   gss_canonicalize_name(), is provided to convert a general internal name
   into an MN.




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   Comparison of internal-form names may be accomplished via the
   gss_compare_name() routine, which returns true if the two names being
   compared refer to the same entity.  This removes the need for the
   application program to understand the syntaxes of the various printable
   names that a given GSS-API implementation may support.  Since GSSAPI
   assumes that all primitive names contained within a given internal name
   refer to the same entity, gss_compare_name() can return true if the two
   names have at least one primitive name in common.  If the implementation
   embodies knowledge of equivalence relationships between names taken from
   different namespaces, this knowledge may also allow successful
   comparison of internal names containing no overlapping primitive
   elements.

   When used in large access control lists, the overhead of invoking
   gss_import_name() and gss_compare_name() on each name from the ACL may
   be prohibitive.  As an alternative way of supporting this case, GSSAPI
   defines a special form of the contiguous string name which may be
   compared directly (e.g. with memcmp()).  Contigous names suitable for
   comparison are generated by the gss_export_name() routine, which
   requires an MN as input.  Exported names may be re-imported by the
   gss_import_name() routine, and the resulting internal name will also be
   an MN.  The gss_OID constant GSS_C_NT_EXPORT_NAME indentifies the
   "export name" type, and the value of this constant is given in Appendix
   A.     Structurally, an exported name object consists of a header
   containing an OID identifying the mechanism that authenticated the name,
   and a trailer containing the name itself, where the syntax of the
   trailer is defined by the individual mechanism specification.   The
   precise format of an export name is defined in the language-independent
   GSSAPI specification [GSSAPI].

   Note that the results obtained by using gss_compare_name() will in
   general be different from those obtained by invoking
   gss_canonicalize_name() and gss_export_name(), and then comparing the
   exported names.  The first series of operation determines whether two
   (unauthenticated) names identify the same principal; the second whether
   a particular mechanism would authenticate them as the same principal.
   These two operations will in general give the same results only for MNs.

   The gss_name_t datatype should be implemented as a pointer type.  To
   allow the compiler to aid the application programmer by performing
   type-checking, the use of (void *) is discouraged.  A pointer to an
   implementation-defined type is the preferred choice.

   Storage is allocated by routines that return gss_name_t values.  A
   procedure, gss_release_name, is provided to free storage associated with
   an internal-form name.








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   5.11.  Channel Bindings

   GSS-API supports the use of user-specified tags to identify a given
   context to the peer application.  These tags are intended to be used to
   identify the particular communications channel that carries the context.
   Channel bindings are communicated to the GSS-API using the following
   structure:

        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;

   The initiator_addrtype and acceptor_addrtype fields denote the type of
   addresses contained in the initiator_address and acceptor_address
   buffers.  The address type should be one of the following:

        GSS_C_AF_UNSPEC      Unspecified address type
        GSS_C_AF_LOCAL       Host-local address type
        GSS_C_AF_INET        Internet address type (e.g. IP)
        GSS_C_AF_IMPLINK     ARPAnet IMP address type
        GSS_C_AF_PUP         pup protocols (eg BSP) address type
        GSS_C_AF_CHAOS       MIT CHAOS protocol address type
        GSS_C_AF_NS          XEROX NS address type
        GSS_C_AF_NBS         nbs address type
        GSS_C_AF_ECMA        ECMA address type
        GSS_C_AF_DATAKIT     datakit protocols address type
        GSS_C_AF_CCITT       CCITT protocols
        GSS_C_AF_SNA         IBM SNA address type
        GSS_C_AF_DECnet      DECnet address type
        GSS_C_AF_DLI         Direct data link interface address type
        GSS_C_AF_LAT         LAT address type
        GSS_C_AF_HYLINK      NSC Hyperchannel address type
        GSS_C_AF_APPLETALK   AppleTalk address type
        GSS_C_AF_BSC         BISYNC 2780/3780 address type
        GSS_C_AF_DSS         Distributed system services address type
        GSS_C_AF_OSI         OSI TP4 address type
        GSS_C_AF_X25         X25
        GSS_C_AF_NULLADDR    No address specified

   Note that these symbols name address families rather than specific
   addressing formats.  For address families that contain several
   alternative address forms, the initiator_address and acceptor_address
   fields must contain sufficient information to determine which address
   form is used.  When not otherwise specified, addresses should be
   specified in network byte-order (that is, native byte-ordering for the
   address family).




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   Conceptually, the GSS-API concatenates the initiator_addrtype,
   initiator_address, acceptor_addrtype, acceptor_address and
   application_data to form an octet string.  The mechanism calculates a
   MIC over this octet string, and binds the MIC to the context
   establishment token emitted by gss_init_sec_context.  The same bindings
   are presented by the context acceptor to gss_accept_sec_context, and a
   MIC is calculated in the same way.  The calculated MIC is compared with
   that found in the token, and if the MICs differ, gss_accept_sec_context
   will return a GSS_S_BAD_BINDINGS error, and the context will not be
   established.  Some mechanisms may include the actual channel binding
   data in the token (rather than just a MIC); applications should
   therefore not use confidential data as channel-binding components.
   Individual mechanisms may impose additional constraints on addresses and
   address types that may appear in channel bindings.  For example, a
   mechanism may verify that the initiator_address field of the channel
   bindings presented to gss_init_sec_context contains the correct network
   address of the host system.  Portable applications should therefore
   ensure that they either provide correct information for the address
   fields, or omit addressing information, specifying GSS_C_AF_NULLADDR as
   the address-types.

   5.12.  Optional parameters

   Various parameters are described as optional.  This means that they
   follow a convention whereby a default value may be requested.  The
   following conventions are used for omitted parameters.  These
   conventions apply only to those parameters that are explicitly
   documented as optional.

   5.12.1.  gss_buffer_t types

   Specify GSS_C_NO_BUFFER as a value.  For an input parameter this
   signifies that default behavior is requested, while for an output
   parameter it indicates that the information that would be returned via
   the parameter is not required by the application.

   5.12.2.  Integer types (input)

   Individual parameter documentation lists values to be used to indicate
   default actions.

   5.12.3.  Integer types (output)

   Specify NULL as the value for the pointer.

   5.12.4.  Pointer types

   Specify NULL as the value.






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   5.12.5.  Object IDs

   Specify GSS_C_NO_OID as the value.

   5.12.6.  Object ID Sets

   Specify GSS_C_NO_OID_SET as the value.

   5.12.7.  Channel Bindings

   Specify GSS_C_NO_CHANNEL_BINDINGS to indicate that channel bindings are
   not to be used.


   6. ADDITIONAL CONTROLS

   This section discusses the optional services that a context initiator
   may request of the GSS-API at context establishment.  Each of these
   services is requested by setting a flag in the req_flags input parameter
   to gss_init_sec_context.

   The optional services currently defined are:

   Delegation - The (usually temporary) transfer of rights from initiator
         to acceptor, enabling the acceptor to authenticate itself as an
         agent of the initiator.

   Mutual Authentication - In addition to the initiator authenticating its
         identity to the context acceptor, the context acceptor should also
         authenticate itself to the initiator.

   Replay detection - In addition to providing message integrity services,
         gss_get_mic and gss_wrap should include message numbering
         information to enable gss_verify_mic and gss_unwrap to detect if a
         message has been duplicated.

   Out-of-sequence detection - In addition to providing message integrity
         services, gss_get_mic and gss_wrap should include message
         sequencing information to enable gss_verify_mic and gss_unwrap to
         detect if a message has been received out of sequence.

   Anonymous authentication - The establishment of the security context
         should not reveal the initiator's identity to the context
         acceptor.

   Any currently undefined bits within such flag arguments should be
   ignored by GSS-API implementations when presented by an application, and
   should be set to zero when returned to the application by the GSS-API
   implementation.





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   Some mechanisms may not support all optional services, and some
   mechanisms may only support some services in conjunction with others.
   Both gss_init_sec_context and gss_accept_sec_context inform the
   applications which services will be available from the context when the
   establishment phase is complete, via the ret_flags output parameter.  In
   general, if the security mechanism is capable of providing a requested
   service, it should do so, even if additional services must be enabled in
   order to provide the requested service.  If the mechanism is incapable
   of providing a requested service, it should proceed without the service,
   leaving the application to abort the context establishment process if it
   considers the requested service to be mandatory.

   Some mechanisms may specify that support for some services is optional,
   and that implementors of the mechanism need not provide it.  This is
   most commonly true of the confidentiality service, often because of
   legal restrictions on the use of data-encryption, but may apply to any
   of the services.  Such mechanisms are required to send at least one
   token from acceptor to initiator during context establishment when the
   initiator indicates a desire to use such a service, so that the
   initiating GSSAPI can correctly indicate whether the service is
   supported by the acceptor's GSSAPI.

   6.1.  Delegation

   The GSS-API allows delegation to be controlled by the initiating
   application via a boolean parameter to gss_init_sec_context(), the
   routine that establishes a security context.  Some mechanisms do not
   support delegation, and for such mechanisms attempts by an application
   to enable delegation are ignored.

   The acceptor of a security context for which the initiator enabled
   delegation will receive (via the delegated_cred_handle parameter of
   gss_accept_sec_context) a credential handle that contains the delegated
   identity, and this credential handle may be used to initiate subsequent
   GSSAPI security contexts as an agent or delegate of the initiator.  If
   the original initiator's identity is "A" and the delegate's identity is
   "B", then, depending on the underlying mechanism, the identity embodied
   by the delegated credential may be either "A" or "B acting for A".

   For many mechanisms that support delegation, a simple boolean does not
   provide enough control.  Examples of additional aspects of delegation
   control that a mechanism might provide to an application are duration of
   delegation, network addresses from which delegation is valid, and
   constraints on the tasks that may be performed by a delegate.  Such
   controls are presently outside the scope of the GSS-API.  GSS-API
   implementations supporting mechanisms offering additional controls
   should provide extension routines that allow these controls to be
   exercised (perhaps by modifying the initiator's GSS-API credential prior
   to its use in establishing a context).  However, the simple delegation
   control provided by GSS-API should always be able to over-ride other
   mechanism-specific delegation controls - If the application instructs



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   gss_init_sec_context() that delegation is not desired, then the
   implementation must not permit delegation to occur.  This is an
   exception to the general rule that a mechanism may enable services even
   if they are not requested - delegation may only be provide at the
   explicit request of the application.

   6.2.  Mutual authentication

   Usually, a context acceptor will require that a context initiator
   authenticate itself so that the acceptor may make an access-control
   decision prior to performing a service for the initiator.  In some
   cases, the initiator may also request that the acceptor authenticate
   itself.  GSS-API allows the initiating application to request this
   mutual authentication service by setting a flag when calling
   gss_init_sec_context.

   The initiating application is informed as to whether or not mutual
   authentication is being requested of the context acceptor.  Note that
   some mechanisms may not support mutual authentication, and other
   mechanisms may always perform mutual authentication, whether or not the
   initiating application requests it.  In particular, mutual
   authentication my be required by some mechanisms in order to support
   replay or out-of-sequence message detection, and for such mechanisms a
   request for either of these services will automatically enable mutual
   authentication.

   6.3.  Replay and out-of-sequence detection

   The GSS-API may provide detection of mis-ordered message once a security
   context has been established.  Protection may be applied to messages by
   either application, by calling either gss_get_mic or gss_wrap, and
   verified by the peer application by calling gss_verify_mic or
   gss_unwrap.

   gss_get_mic calculates a cryptographic checksum of an application
   message, and returns that checksum in a token.  The application should
   pass both the token and the message to the peer application, which
   presents them to gss_verify_mic.

   gss_wrap calculates a cryptographic checksum of an application message,
   and places both the checksum and the message inside a single token.  The
   application should pass the token to the peer application, which
   presents it to gss_unwrap to extract the message and verify the
   checksum.

   Either pair of routines may be capable of detecting out-of-sequence
   message delivery, or duplication of messages. Details of such mis-
   ordered messages are indicated through supplementary status bits in the
   major status code returned by gss_verify_mic or gss_unwrap.  The
   relevant supplementary bits are:




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   GSS_S_DUPLICATE_TOKEN - The token is a duplicate of one that has already
         been received and processed.  Contexts that do not claim to
         provide replay detection may still set this bit if the duplicate
         message is processed immediately after the original, with no
         intervening messages.

   GSS_S_OLD_TOKEN - The token is too old to determine whether or not it is
         a duplicate.  Contexts supporting out-of-sequence detection but
         not replay detection should always set this bit if
         GSS_S_UNSEQ_TOKEN is set; contexts that support replay detection
         should only set this bit if the token is so old that it cannot be
         checked for duplication.

   GSS_S_UNSEQ_TOKEN - A later token has already been processed.

   GSS_S_GAP_TOKEN - An earlier token has not yet been received.

   A mechanism need not maintain a list of all tokens that have been
   processed in order to support these status codes.  A typical mechanism
   might retain information about only the most recent "N" tokens
   processed, allowing it to distinguish duplicates and missing tokens
   within the most recent "N" messages; the receipt of a token older than
   the most recent "N" would result in a GSS_S_OLD_TOKEN status.

   6.4.  Anonymous Authentication

   In certain situations, an application may wish to initiate the
   authentication process to authenticate a peer, without revealing its own
   identity.  As an example, consider an application providing access to a
   database containing medical information, and offering unrestricted
   access to the service.  A client of such a service might wish to
   authenticate the service (in order to establish trust in any information
   retrieved from it), but might not wish the service to be able to obtain
   the client's identity (perhaps due to privacy concerns about the
   specific inquiries, or perhaps simply to avoid being placed on mailing-
   lists).

   In normal use of the GSS-API, the initiator's identity is made available
   to the acceptor as a result of the context establishment process.
   However, context initiators may request that their identity not be
   revealed to the context acceptor.  Many mechanisms do not support
   anonymous authentication, and for such mechanisms the request will not
   be honored.  An authentication token will be still be generated, but the
   application is always informed if a requested service is unavailable,
   and has the option to abort context establishment if anonymity is valued
   above the other security services that would require a context to be
   established.

   In addition to informing the application that a context is established
   anonymously (via the ret_flags outputs from gss_init_sec_context and
   gss_accept_sec_context), the optional src_name output from



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   gss_accept_sec_context and gss_inquire_context will, for such contexts,
   return a reserved internal-form name, defined by the implementation.
   When presented to gss_display_name, this reserved internal-form name
   will result in a printable name that is syntactically distinguishable
   from any valid principal name supported by the implementation,
   associated with a name-type object identifier with the value
   GSS_C_NT_ANONYMOUS, whose value us given in Appendix A.  The printable
   form of an anonymous name should be chosen such that it implies
   anonymity, since this name may appear in, for example, audit logs.  For
   example, the string "<anonymous>" might be a good choice, if no valid
   printable names supported by the implementation can begin with "<" and
   end with ">".

   6.5.  Confidentiality

   If a context supports the confidentiality service, gss_wrap may be used
   to encrypt application messages.  Messages are selectively encrypted,
   under the control of the conf_req_flag input parameter to gss_wrap.

   6.6.  Inter-process context transfer

   GSSAPI V2 provides routines (gss_export_sec_context and
   gss_import_sec_context) which allow a security context to be transferred
   between processes on a single machine.  The most common use for such a
   feature is a client-server design where the server is implemented as a
   single process that accepts incoming security contexts, which then
   launches child processes to deal with the data on these contexts.  In
   such a design, the child processes must have access to the security
   context data structure created within the parent by its call to
   gss_accept_sec_context so that they can use per-message protection
   services and delete the security context when the communication session
   ends.

   Since the security context data structure is expected to contain
   sequencing information, it is impractical in general to share a context
   between processes.  Thus GSSAPI provides a call (gss_export_sec_context)
   that the process which currently owns the context can call to declare
   that it has no intention to use the context subsequently, and to create
   an inter-process token containing information needed by the adopting
   process to successfully import the context.  After successful completion
   of this call, the original security context is made inaccessible to the
   calling process by GSSAPI, and any context handles referring to this
   context are no longer valid.  The originating process transfers the
   inter-process token to the adopting process, which passes it to
   gss_import_sec_context, and a fresh gss_ctx_id_t is created such that it
   is functionally identical to the original context.

   The inter-process token may contain sensitive data from the original
   security context (including cryptographic keys).  Applications using
   inter-process tokens to transfer security contexts must take appropriate
   steps to protect these tokens in transit.



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   Implementations are not required to support the inter-process transfer
   of security contexts.  The ability to transfer a security context is
   indicated when the context is created, by gss_init_sec_context or
   gss_accept_sec_context setting the GSS_C_TRANS_FLAG bit in their
   ret_flags parameter.


   6.7.  The use of incomplete contexts

   Some mechanisms may allow the per-message services to be used before the
   context establishment process is complete.  For example, a mechanism may
   include sufficient information in its initial context-level token for
   the context acceptor to immediately decode messages protected with
   gss_wrap or gss_get_mic.  For such a mechanism, the initiating
   application need not wait until subsequent context-level tokens have
   been sent and received before invoking the per-message protection
   services.

   The ability of a context to provide per-message services in advance of
   complete context establishment is indicated by the setting of the
   GSS_C_PROT_READY_FLAG bit in the ret_flags parameter from
   gss_init_sec_context and gss_accept_sec_context.  Applications wishing
   to use per-message protection services on partially-established contexts
   should check this flag before attempting to invoke gss_wrap or
   gss_get_mic.



   7. GSS-API routine descriptions

   In addition to the explicit major status codes documented here, the code
   GSS_S_FAILURE may be returned by any routine, indicating an
   implementation-specific or mechanism-specific error condition, further
   details of which are reported via the minor_status parameter.




















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   7.1.  gss_accept_sec_context

   OM_uint32 gss_accept_sec_context (
        OM_uint32 *              minor_status,
        gss_ctx_id_t *           context_handle,
        const gss_cred_id_t      acceptor_cred_handle,
        const gss_buffer_t       input_token_buffer,
        const gss_channel_bindings_t
                                 input_chan_bindings,
        const gss_name_t *       src_name,
        gss_OID *                mech_type,
        gss_buffer_t             output_token,
        OM_uint32 *              ret_flags,
        OM_uint32 *              time_rec,
        gss_cred_id_t *          delegated_cred_handle)

   Purpose:

   Allows a remotely initiated security context between the application and
   a remote peer to be established.  The routine may return a output_token
   which should be transferred to the peer application, where the peer
   application will present it to gss_init_sec_context.  If no token need
   be sent, gss_accept_sec_context will indicate this by setting the length
   field of the output_token argument to zero.  To complete the context
   establishment, one or more reply tokens may be required from the peer
   application; if so, gss_accept_sec_context  will return a status flag of
   GSS_S_CONTINUE_NEEDED, in which case it should be called again when the
   reply token is received from the peer application, passing the token to
   gss_accept_sec_context via the input_token parameters.

   Portable applications should be constructed to use the token length and
   return status to determine whether a token needs to be sent or waited
   for.  Thus a typical portable caller should always invoke
   gss_accept_sec_context within a loop:

       gss_ctx_id_t context_hdl = GSS_C_NO_CONTEXT;
       ...

       do {
          receive_token_from_peer(input_token);
          maj_stat = gss_accept_sec_context(&min_stat,
                                            &context_hdl,
                                            cred_hdl,
                                            input_token,
                                            input_bindings,
                                            &client_name,
                                            &mech_type,
                                            output_token,
                                            &ret_flags,
                                            &time_rec,
                                            &deleg_cred);



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          if (GSS_ERROR(maj_stat)) {
             report_error(maj_stat, min_stat);
          };
          if (output_token->length != 0) {
             send_token_to_peer(output_token);
             gss_release_buffer(&min_stat,
                                output_token)
          };
          if (GSS_ERROR(maj_stat)) {
             if (context_hdl != GSS_C_NO_CONTEXT)
                gss_delete_sec_context(&min_stat,
                                       &context_hdl,
                                       GSS_C_NO_BUFFER);
             break;
          };
       } while (maj_stat & GSS_S_CONTINUE_NEEDED);


   Whenever the routine returns a major status that includes the value
   GSS_S_CONTINUE_NEEDED, the context is not fully established and the
   following restrictions apply to the output parameters:

     (a) The value returned via the time_rec parameter is undefined

     (b) Unless the accompanying ret_flags parameter contains the bit
         GSS_C_PROT_READY_FLAG, indicating that per-message services may be
         applied in advance of a successful completion status, the value
         returned via the mech_type parameter may be undefined until the
         routine returns a major status value of GSS_S_COMPLETE.

     (c) The values of the GSS_C_DELEG_FLAG, GSS_C_MUTUAL_FLAG,
         GSS_C_REPLAY_FLAG, GSS_C_SEQUENCE_FLAG, GSS_C_CONF_FLAG,
         GSS_C_INTEG_FLAG and GSS_C_ANON_FLAG bits returned via the
         ret_flags parameter should contain the values that the
         implementation expects would be valid if context establishment
         were to succeed.

         The values of the GSS_C_PROT_READY_FLAG and GSS_C_TRANS_FLAG bits
         within ret_flags should indicate the actual state at the time
         gss_accept_sec_context returns, whether or not the context is
         fully established.

         Although this requires that GSSAPI implementations set the
         GSS_C_PROT_READY_FLAG in the final ret_flags returned to a caller
         (i.e. when accompanied by a GSS_S_COMPLETE status code),
         applications should not rely on this behavior as the flag was not
         defined in Version 1 of the GSSAPI. Instead, applications should
         be prepared to use per-message services after a successful context
         establishment, according to the GSS_C_INTEG_FLAG and
         GSS_C_CONF_FLAG values.




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         All other bits within the ret_flags argument should be set to
         zero.


   While the routine returns GSS_S_CONTINUE_NEEDED, the values returned via
   the ret_flags argument indicate the services that the implementation
   expects to be available from the established context.

   If the initial call of gss_accept_sec_context() fails, the
   implementation should not create a context object, and should leave the
   value of the context_handle parameter set to GSS_C_NO_CONTEXT to
   indicate this.  In the event of a failure on a subsequent call, the
   implementation is permitted to delete the "half-built" security context
   (in which case it should set the context_handle parameter to
   GSS_C_NO_CONTEXT), but the preferred behavior is to leave the security
   context (and the context_handle parameter) untouched for the application
   to delete (using gss_delete_sec_context).

   Parameters:

   context_handle    gss_ctx_id_t, read/modify
                     context handle for new context.  Supply
                     GSS_C_NO_CONTEXT for first call; use value
                     returned in subsequent calls.  Once
                     gss_accept_sec_context() has returned a value
                     via this parameter, resources have been assigned
                     to the corresponding context, and must be
                     freed by the application after use with a call
                     to gss_delete_sec_context().


   acceptor_cred_handle  gss_cred_id_t, read
                     Credential handle claimed by context acceptor.
                     Specify GSS_C_NO_CREDENTIAL to accept the
                     context as a default principal.  If
                     GSS_C_NO_CREDENTIAL is specified, but no
                     default acceptor principal is defined,
                     GSS_S_NO_CRED will be returned.

   input_token_buffer  buffer, opaque, read
                     token obtained from remote application.

   input_chan_bindings  channel bindings, read, optional
                     Application-specified bindings.  Allows
                     application to securely bind channel
                     identification information to the security
                     context.  If channel bindings are not
                     used, specify GSS_C_NO_CHANNEL_BINDINGS.

   src_name          gss_name_t, modify, optional
                     Authenticated name of context initiator.



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                     After use, this name should be deallocated by
                     passing it to gss_release_name().  If not
                     required, specify NULL.

   mech_type         Object ID, modify, optional
                     Security mechanism used.  The returned
                     OID value will be a pointer into static
                     storage, and should be treated as read-only
                     by the caller (in particular, it does not
                     need to be freed).  If not required, specify
                     NULL.

   output_token      buffer, opaque, modify
                     Token to be passed to peer application. If the
                     length field of the returned token buffer is 0,
                     then no token need be passed to the peer
                     application.  If a non-zero length field is
                     returned, the associated storage must be freed
                     after use by the application with a call to
                     gss_release_buffer().

   ret_flags         bit-mask, modify, optional
                     Contains various independent flags, each of
                     which indicates that the context supports a
                     specific service option.  If not needed,
                     specify NULL.  Symbolic names are
                     provided for each flag, and the symbolic names
                     corresponding to the required flags
                     should be logically-ANDed with the ret_flags
                     value to test whether a given option is
                     supported by the context.  The flags are:
                     GSS_C_DELEG_FLAG
                           True - Delegated credentials are available
                                  via the delegated_cred_handle
                                  parameter
                           False - No credentials were delegated
                     GSS_C_MUTUAL_FLAG
                           True - Remote peer asked for mutual
                                  authentication
                           False - Remote peer did not ask for mutual
                                   authentication
                     GSS_C_REPLAY_FLAG
                           True - replay of protected messages
                                  will be detected
                           False - replayed messages will not be
                                   detected
                     GSS_C_SEQUENCE_FLAG
                           True - out-of-sequence protected
                                  messages will be detected
                           False - out-of-sequence messages will not
                                   be detected



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                     GSS_C_CONF_FLAG
                           True - Confidentiality service may be invoked
                                  by calling the gss_wrap routine
                           False - No confidentiality service (via
                                   gss_wrap) available. gss_wrap will
                                   provide message encapsulation,
                                   data-origin authentication and
                                   integrity services only.
                     GSS_C_INTEG_FLAG
                           True - Integrity service may be invoked by
                                  calling either gss_get_mic or gss_wrap
                                  routines.
                           False - Per-message integrity service
                                   unavailable.
                     GSS_C_ANON_FLAG
                           True - The initiator does not wish to
                                  be authenticated; the src_name
                                  parameter (if requested) contains
                                  an anonymous internal name.
                           False - The initiator has been
                                   authenticated normally.
                     GSS_C_PROT_READY_FLAG
                           True - Protection services (as specified
                                  by the states of the GSS_C_CONF_FLAG
                                  and GSS_C_INTEG_FLAG) are available
                                  if the accompanying major status return
                                  value is either GSS_S_COMPLETE or
                                  GSS_S_CONTINUE_NEEDED.
                           False - Protection services (as specified
                                   by the states of the GSS_C_CONF_FLAG
                                   and GSS_C_INTEG_FLAG) are available
                                   only if the accompanying major status
                                   return value is GSS_S_COMPLETE.
                     GSS_C_TRANS_FLAG
                           True - The resultant security context may
                                  be transferred to other processes via
                                  a call to gss_export_sec_context().
                           False - The security context is not
                                   transferrable.
                     All other bits should be set to zero.

   time_rec          Integer, modify, optional
                     number of seconds for which the context
                     will remain valid. Specify NULL if not required.

   delegated_cred_handle
                     gss_cred_id_t, modify, optional
                     credential handle for credentials received from
                     context initiator.  Only valid if deleg_flag in
                     ret_flags is true, in which case an explicit



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                     credential handle (i.e. not GSS_C_NO_CREDENTIAL)
                     will be returned; if deleg_flag is false,
                     gss_accept_context() will set this parameter to
                     GSS_C_NO_CREDENTIAL.  If a credential handle is
                     returned, the associated resources must be released
                     by the application after use with a call to
                     gss_release_cred().  Specify NULL if not required.


   minor_status      Integer, modify
                     Mechanism specific status code.


   Function value:  GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_CONTINUE_NEEDED Indicates that a token from the peer application
                     is required to complete the context, and that
                     gss_accept_sec_context must be called again with that
                     token.

   GSS_S_DEFECTIVE_TOKEN Indicates that consistency checks performed on the
                     input_token failed.

   GSS_S_DEFECTIVE_CREDENTIAL Indicates that consistency checks performed
                     on the credential failed.

   GSS_S_NO_CRED     The supplied credentials were not valid for context
                     acceptance, or the credential handle did not reference
                     any credentials.

   GSS_S_CREDENTIALS_EXPIRED The referenced credentials have expired.

   GSS_S_BAD_BINDINGS The input_token contains different channel bindings
                     to those specified via the input_chan_bindings
                     parameter.

   GSS_S_NO_CONTEXT  Indicates that the supplied context handle did not
                     refer to a valid context.

   GSS_S_BAD_SIG     The input_token contains an invalid MIC.

   GSS_S_OLD_TOKEN   The input_token was too old.  This is a fatal error
                     during context establishment.

   GSS_S_DUPLICATE_TOKEN The input_token is valid, but is a duplicate of a
                     token already processed.  This is a fatal error during
                     context establishment.





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   GSS_S_BAD_MECH    The received token specified a mechanism that is not
                     supported by the implementation or the provided
                     credential.







   7.2.  gss_acquire_cred


   OM_uint32 gss_acquire_cred (
        OM_uint32 *              minor_status,
        const gss_name_t         desired_name,
        OM_uint32                time_req,
        const gss_OID_set        desired_mechs,
        gss_cred_usage_t         cred_usage,
        gss_cred_id_t *          output_cred_handle,
        gss_OID_set *            actual_mechs,
        OM_uint32 *              time_rec)

   Purpose:

   Allows an application to acquire a handle for a pre-existing credential
   by name.  GSS-API implementations must impose a local access-control
   policy on callers of this routine to prevent unauthorized callers from
   acquiring credentials to which they are not entitled.  This routine is
   not intended to provide a ``login to the network'' function, as such a
   function would involve the creation of new credentials rather than
   merely acquiring a handle to existing credentials.  Such functions, if
   required, should be defined in implementation-specific extensions to the
   API.

   If desired_name is GSS_C_NO_NAME, the call is interpreted as a request
   for a credential handle that will invoke default behavior when passed to
   gss_init_sec_context() (if cred_usage is GSS_C_INITIATE or GSS_C_BOTH)
   or gss_accept_sec_context() (if cred_usage is GSS_C_ACCEPT or
   GSS_C_BOTH).

   This routine is expected to be used primarily by context acceptors,
   since implementations are likely to provide mechanism-specific ways of
   obtaining GSS-API initiator credentials from the system login process.
   Some implementations may therefore not support the acquisition of
   GSS_C_INITIATE or GSS_C_BOTH credentials via gss_acquire_cred for any
   name other than an empty name.

   If credential acquisition is time-consuming for a mechanism, the
   mechanism may chooses to delay the actual acquisition until the
   credential is required (e.g. by gss_init_sec_context or



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   gss_accept_sec_context).  Such mechanism-specific implementation
   decisions should be invisible to the calling application; thus a call of
   gss_inquire_cred immediately following the call of gss_acquire_cred must
   return valid credential data, and may therefore incur the overhead of a
   deferred credential acquisition.

   Parameters:

   desired_name      gss_name_t, read
                     Name of principal whose credential
                     should be acquired

   time_req          Integer, read, optional
                     number of seconds that credentials
                     should remain valid. Specify GSS_C_INDEFINITE
                     to request that the credentials have the maximum
                     permitted lifetime.

   desired_mechs     Set of Object IDs, read, optional
                     set of underlying security mechanisms that
                     may be used.  GSS_C_NO_OID_SET may be used
                     to obtain an implementation-specific default.

   cred_usage        gss_cred_usage_t, read
                     GSS_C_BOTH - Credentials may be used
                                  either to initiate or accept
                                  security contexts.
                     GSS_C_INITIATE - Credentials will only be
                                      used to initiate security
                                      contexts.
                     GSS_C_ACCEPT - Credentials will only be used to
                                    accept security contexts.

   output_cred_handle  gss_cred_id_t, modify
                     The returned credential handle.  Resources
                     associated with this credential handle must
                     be released by the application after use
                     with a call to gss_release_cred().

   actual_mechs      Set of Object IDs, modify, optional
                     The set of mechanisms for which the
                     credential is valid.  Storage associated
                     with the returned OID-set must be released by
                     the application after use with a call to
                     gss_release_oid_set().  Specify NULL if not
                     required.

   time_rec          Integer, modify, optional
                     Actual number of seconds for which the
                     returned credentials will remain valid.  If the
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                     credentials, the value GSS_C_INDEFINITE will
                     be returned. Specify NULL if not required

   minor_status      Integer, modify
                     Mechanism specific status code.

   Function value:  GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_MECH    Unavailable mechanism requested

   GSS_S_BAD_NAMETYPE Type contained within desired_name parameter is not
                     supported

   GSS_S_BAD_NAME    Value supplied for desired_name parameter is ill-
                     formed.

   GSS_S_CREDENTIALS_EXPIRED The credentials could not be acquired because
                     they have expired.

   GSS_S_NO_CRED     No credentials were found for the specified name.







   7.3.  gss_add_cred


   OM_uint32 gss_add_cred (
        OM_uint32 *              minor_status,
        const gss_cred_id_t      input_cred_handle,
        const gss_name_t         desired_name,
        const gss_OID            desired_mech,
        gss_cred_usage_t         cred_usage,
        OM_uint32                initiator_time_req,
        OM_uint32                acceptor_time_req,
        gss_cred_id_t *          output_cred_handle,
        gss_OID_set *            actual_mechs,
        OM_uint32 *              initiator_time_rec,
        OM_uint32 *              acceptor_time_rec)










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   Purpose:

   Adds a credential-element to a credential.  The credential-element is
   identified by the name of the principal to which it refers.  GSSAPI
   implementations must impose a local access-control policy on callers of
   this routine to prevent unauthorized callers from acquiring credential-
   elements to which they are not entitled. This routine is not intended to
   provide a ``login to the network'' function, as such a function would
   involve the creation of new mechanism-specific authentication data,
   rather than merely acquiring a GSSAPI handle to existing data.  Such
   functions, if required, should be defined in implementation-specific
   extensions to the API.

   This routine is expected to be used primarily by context acceptors,
   since implementations are likely to provide mechanism-specific ways of
   obtaining GSS-API initiator credentials from the system login process.
   Some implementations may therefore not support the acquisition of
   GSS_C_INITIATE or GSS_C_BOTH credentials via gss_acquire_cred.

   If credential acquisition is time-consuming for a mechanism, the
   mechanism may chooses to delay the actual acquisition until the
   credential is required (e.g. by gss_init_sec_context or
   gss_accept_sec_context).  Such mechanism-specific implementation
   decisions should be invisible to the calling application; thus a call of
   gss_inquire_cred immediately following the call of gss_acquire_cred must
   return valid credential data, and may therefore incur the overhead of a
   deferred credential acquisition.

   This routine can be used to either create a new credential containing
   all credential-elements of the original in addition to the newly-acquire
   credential-element, or to add the new credential-element to an existing
   credential. If NULL is specified for the output_cred_handle parameter
   argument, the new credential-element will be added to the credential
   identified by input_cred_handle; if a valid pointer is specified for the
   output_cred_handle parameter, a new credential and handle will be
   created.

   If GSS_C_NO_CREDENTIAL is specified as the input_cred_handle, the
   gss_add_cred will create its output_cred_handle based on default
   behavior.  That is, the call will have the same effect as if the
   application had first made a call to gss_acquire_cred(), specifying the
   same usage and passing GSS_C_NO_NAME as the desired_name parameter to
   obtain an explicit credential handle embodying default behavior, passed
   this credential handle to gss_add_cred(), and finally called
   gss_release_cred() on the first credential handle.

   If GSS_C_NO_CREDENTIAL is specified as the input_cred_handle parameter,
   a non-NULL output_cred_handle must be supplied.

   Parameters:




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   minor_status      Integer, modify
                     Mechanism specific status code.

   input_cred_handle gss_cred_id_t, read, optional
                     The credential to which a credential-element
                     will be added.  If GSS_C_NO_CREDENTIAL is
                     specified, the routine will create the new
                     credential based on default behavior (see
                     description above).  Note that, while the
                     credential-handle is not modified by
                     gss_add_cred(), the underlying credential
                     will be modified if output_credential_handle
                     is NULL.

   desired_name      gss_name_t, read.
                     Name of principal whose credential
                     should be acquired.

   desired_mech      Object ID, read
                     Underlying security mechanism with which the
                     credential may be used.

   cred_usage        gss_cred_usage_t, read
                     GSS_C_BOTH - Credential may be used
                                  either to initiate or accept
                                  security contexts.
                     GSS_C_INITIATE - Credential will only be
                                      used to initiate security
                                      contexts.
                     GSS_C_ACCEPT - Credential will only be used to
                                    accept security contexts.

   initiator_time_req Integer, read, optional
                     number of seconds that the credential
                     should remain valid for initiating security
                     contexts.  This argument is ignored if the
                     created credentials are of type GSS_C_ACCEPT.
                     Specify GSS_C_INDEFINITE to request that the
                     credentials have the maximum permitted initiator
                     lifetime.

   acceptor_time_req Integer, read, optional
                     number of seconds that the credential
                     should remain valid for accepting security
                     contexts.  This argument is ignored if the
                     created credentials are of type GSS_C_INITIATE.
                     Specify GSS_C_INDEFINITE to request that the
                     credentials have the maximum permitted initiator
                     lifetime.




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   output_cred_handle gss_cred_id_t, modify, optional
                     The returned credential handle, containing
                     the new credential-element and all the
                     credential-elements from input_cred_handle.
                     If a valid pointer to a gss_cred_id_t is
                     supplied for this parameter, gss_add_cred
                     creates a new credential handle containing all
                     credential-elements from the input_cred_handle
                     and the newly acquired credential-element; if
                     NULL is specified for this parameter, the newly
                     acquired credential-element will be added
                     to the credential identified by input_cred_handle.
                     The resources associated with any credential
                     handle returned via this parameter must be
                     released by the application after use with a
                     call to gss_release_cred().

   actual_mechs      Set of Object IDs, modify, optional
                     The complete set of mechanisms for which
                     the new credential is valid.  Storage for
                     the returned OID-set must be freed by the
                     application after use with a call to
                     gss_release_oid_set(). Specify NULL if
                     not required.

   initiator_time_rec Integer, modify, optional
                     Actual number of seconds for which the
                     returned credentials will remain valid for
                     initiating contexts using the specified
                     mechanism.  If the implementation or mechanism
                     does not support expiration of credentials, the
                     value GSS_C_INDEFINITE will be returned. Specify
                     NULL if not required

   acceptor_time_rec Integer, modify, optional
                     Actual number of seconds for which the
                     returned credentials will remain valid for
                     accepting security contexts using the specified
                     mechanism.  If the implementation or mechanism
                     does not support expiration of credentials, the
                     value GSS_C_INDEFINITE will be returned. Specify
                     NULL if not required

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_MECH    Unavailable mechanism requested

   GSS_S_BAD_NAMETYPE Type contained within desired_name parameter is not
                     supported




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   GSS_S_BAD_NAME    Value supplied for desired_name parameter is ill-
                     formed.

   GSS_S_DUPLICATE_ELEMENT The credential already contains an element for
                     the requested mechanism with overlapping usage and
                     validity period.

   GSS_S_CREDENTIALS_EXPIRED The required credentials could not be added
                     because they have expired.

   GSS_S_NO_CRED     No credentials were found for the specified name.







   7.4.  gss_add_oid_set_member

   OM_uint32 gss_add_oid_set_member (
        OM_uint32  *             minor_status,
        const gss_OID            member_oid,
        gss_OID_set *            oid_set)

   Purpose:

   Add an Object Identifier to an Object Identifier set.  This routine is
   intended for use in conjunction with gss_create_empty_oid_set when
   constructing a set of mechanism OIDs for input to gss_acquire_cred.

   The oid_set parameter must refer to an OID-set that was created by
   GSSAPI (e.g. a set returned by gss_create_empty_oid_set()).  GSSAPI
   creates a copy of the member_oid and inserts this copy into the set,
   expanding the storage allocated to the OID-set's elements array if
   necessary.  The routine may add the new member OID anywhere within the
   elements array, and implementations should verify that the new
   member_oid is not already contained within the elements array.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   member_oid        Object ID, read
                     The object identifier to copied into
                     the set.

   oid_set           Set of Object ID, modify
                     The set in which the object identifier
                     should be inserted.



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   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion







   7.5.  gss_canonicalize_name

   OM_uint32 gss_canonicalize_name (
        OM_uint32  *             minor_status,
        const gss_name_t         input_name,
        const gss_OID            mech_type,
        gss_name_t *             output_name)

   Purpose:

   Generate a canonical mechanism name (MN) from an arbitrary internal
   name.  The mechanism name is the name that would be returned to a
   context acceptor on successful authentication of a context where the
   initiator used the input_name in a successful call to gss_acquire_cred,
   specifying an OID set containing <mech_type> as its only member,
   followed by a call to gss_init_sec_context, specifying <mech_type> as
   the authentication mechanism.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   input_name        gss_name_t, read
                     The name for which a canonical form is
                     desired

   mech_type         Object ID, read
                     The authentication mechanism for which the
                     canonical form of the name is desired.  The
                     desired mechanism must be specified explicitly;
                     no default is provided.

   output_name       gss_name_t, modify
                     The resultant canonical name.  Storage
                     associated with this name must be freed by
                     the application after use with a call to
                     gss_release_name().

   Function value:   GSS status code




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   GSS_S_COMPLETE    Successful completion.

   GSS_S_BAD_MECH    The identified mechanism is not supported.

   GSS_S_BAD_NAMETYPE The provided internal name contains no elements that
                     could be processed by the sepcified mechanism.

   GSS_S_BAD_NAME    The provided internal name was ill-formed.







   7.6.  gss_compare_name

   OM_uint32 gss_compare_name (
        OM_uint32 *              minor_status,
        const gss_name_t         name1,
        const gss_name_t         name2,
        int *                    name_equal)

   Purpose:

   Allows an application to compare two internal-form names to determine
   whether they refer to the same entity.

   If either name presented to gss_compare_name denotes an anonymous
   principal, the routines should indicate that the two names do not refer
   to the same identity.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   name1             gss_name_t, read
                     internal-form name

   name2             gss_name_t, read
                     internal-form name

   name_equal        boolean, modify
                     non-zero - names refer to same entity
                     zero - names refer to different entities
                            (strictly, the names are not known
                            to refer to the same identity).

   Function value:   GSS status code




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   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_NAMETYPE The two names were of incomparable types.

   GSS_S_BAD_NAME    One or both of name1 or name2 was ill-formed







   7.7.  gss_context_time

   OM_uint32 gss_context_time (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        OM_uint32 *              time_rec)

   Purpose:

   Determines the number of seconds for which the specified context will
   remain valid.

   Parameters:

   minor_status      Integer, modify
                     Implementation specific status code.

   context_handle    gss_ctx_id_t, read
                     Identifies the context to be interrogated.

   time_rec          Integer, modify
                     Number of seconds that the context will remain
                     valid.  If the context has already expired,
                     zero will be returned.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_CONTEXT_EXPIRED The context has already expired

   GSS_S_NO_CONTEXT  The context_handle parameter did not identify a valid
                     context









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   7.8.  gss_create_empty_oid_set

   OM_uint32 gss_create_empty_oid_set (
        OM_uint32  *             minor_status,
        gss_OID_set *            oid_set)

   Purpose:

   Create an object-identifier set containing no object identifiers, to
   which members may be subsequently added using the
   gss_add_oid_set_member() routine.  These routines are intended to be
   used to construct sets of mechanism object identifiers, for input to
   gss_acquire_cred.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   oid_set           Set of Object IDs, modify
                     The empty object identifier set.
                     The routine will allocate the
                     gss_OID_set_desc object, which the
                     application must free after use with
                     a call to gss_release_oid_set().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion







   7.9.  gss_delete_sec_context

   OM_uint32 gss_delete_sec_context (
       OM_uint32 *               minor_status,
       gss_ctx_id_t *            context_handle,
       gss_buffer_t              output_token)

   Purpose:

   Delete a security context.  gss_delete_sec_context will delete the local
   data structures associated with the specified security context, and may
   generate an output_token, which when passed to the peer
   gss_process_context_token will instruct it to do likewise.  If no token
   is required by the mechanism, the GSS-API should set the length field of
   the output_token (if provided) to zero.  No further security services



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   may be obtained using the context specified by context_handle.

   In addition to deleting established security contexts,
   gss_delete_sec_context must also be able to delete "half-built" security
   contexts resulting from an incomplete sequence of
   gss_init_sec_context()/gss_accept_sec_context() calls.

   The output_token parameter is retained for compatibility with version 1
   of the GSS-API.  It is recommended that both peer applications invoke
   gss_delete_sec_context passing the value GSS_C_NO_BUFFER for the
   output_token parameter, indicating that no token is required, and that
   gss_delete_sec_context should simply delete local context data
   structures.  If the application does pass a valid buffer to
   gss_delete_sec_context, mechanisms are encouraged to return a zero-
   length token, indicating that no peer action is necessary, and that no
   token should be transferred by the application.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   context_handle    gss_ctx_id_t, modify
                     context handle identifying context to delete.
                     After deleting the context, the GSSAPI will set
                     this context handle to GSS_C_NO_CONTEXT.

   output_token      buffer, opaque, modify, optional
                     token to be sent to remote application to
                     instruct it to also delete the context.  It
                     is recommended that applications specify
                     GSS_C_NO_BUFFER for this parameter, requesting
                     local deletion only.  If a buffer parameter is
                     provided by the application, the mechanism may
                     return a token in it;  mechanisms that implement
                     only local deletion should set the length field of
                     this token to zero to indicate to the application
                     that no token is to be sent to the peer.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NO_CONTEXT  No valid context was supplied










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   7.10.  gss_display_name

   OM_uint32 gss_display_name (
        OM_uint32 *              minor_status,
        const gss_name_t         input_name,
        gss_buffer_t             output_name_buffer,
        gss_OID *                output_name_type)

   Purpose:

   Allows an application to obtain a textual representation of an opaque
   internal-form  name for display purposes.  The syntax of a printable
   name is defined by the GSS-API implementation.

   If input_name denotes an anonymous principal, the implementation should
   return the gss_OID value GSS_C_NT_ANONYMOUS as the output_name_type, and
   a textual name that is syntactically distinct from all valid supported
   printable names in output_name_buffer.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   input_name        gss_name_t, read
                     name to be displayed

   output_name_buffer  buffer, character-string, modify
                     buffer to receive textual name string.
                     The application must free storage associated
                     with this name after use with a call to
                     gss_release_buffer().

   output_name_type  Object ID, modify, optional
                     The type of the returned name.  The returned
                     gss_OID will be a pointer into static storage,
                     and should be treated as read-only by the caller
                     (in particular, it does not need to be freed).
                     Specify NULL if not required.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_NAME    input_name was ill-formed









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   7.11.  gss_display_status

   OM_uint32 gss_display_status (
        OM_uint32 *              minor_status,
        OM_uint32                status_value,
        int                      status_type,
        const gss_OID            mech_type,
        OM_uint32 *              message_context,
        gss_buffer_t             status_string)

   Purpose:

   Allows an application to obtain a textual representation of a GSS-API
   status code, for display to the user or for logging purposes.  Since
   some status values may indicate multiple conditions, applications may
   need to call gss_display_status multiple times, each call generating a
   single text string.  The message_context parameter is used by
   gss_acquire_cred to store state information about which error messages
   have already been extracted from a given status_value; message_context
   must be initialized to 0 by the application prior to the first call, and
   gss_display_status will return a non-zero value in this parameter if
   there are further messages to extract.  The message_context parameter
   contains all state information required by gss_display_status in order
   to extract further messages from the status_value;  even when a non-zero
   value is returned in this parameter, the application is not required to
   call gss_display_status again unless subsequent messages are desired.
   The following code extracts all messages from a given status code and
   prints them to stderr:


       OM_uint32 message_context;
       OM_uint32 status_code;
       OM_uint32 maj_status;
       OM_uint32 min_status;
       gss_buffer_desc status_string;

       ...

       message_context = 0;

       do {

           maj_status = gss_display_status (&min_status,
                                            status_code,
                                            GSS_C_GSS_CODE,
                                            GSS_C_NO_OID,
                                            &message_context,
                                            &status_string)

           fprintf(stderr,
                   "%.*s\n",



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                   status_string.length,
                   status_string.value);

           gss_release_buffer(&min_status,
                              &status_string);

       } while (message_context != 0);



   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   status_value      Integer, read
                     Status value to be converted

   status_type       Integer, read
                     GSS_C_GSS_CODE - status_value is a GSS status
                                      code
                     GSS_C_MECH_CODE - status_value is a mechanism
                                       status code

   mech_type         Object ID, read, optional
                     Underlying mechanism (used to interpret a
                     minor status value) Supply GSS_C_NO_OID to
                     obtain the system default.

   message_context   Integer, read/modify
                     Should be initialized to zero by the
                     application prior to the first call.
                     On return from gss_display_status(),
                     a non-zero status_value parameter indicates
                     that additional messages may be extracted
                     from the status code via subsequent calls
                     to gss_display_status(), passing the same
                     status_value, status_type, mech_type, and
                     message_context parameters.

   status_string     buffer, character string, modify
                     textual interpretation of the status_value.
                     Storage associated with this parameter must
                     be freed by the application after use with
                     a call to gss_release_buffer().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion





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   GSS_S_BAD_MECH    Indicates that translation in accordance with an
                     unsupported mechanism type was requested

   GSS_S_BAD_STATUS  The status value was not recognized, or the status
                     type was neither GSS_C_GSS_CODE nor GSS_C_MECH_CODE.







   7.12.  gss_duplicate_name

   OM_uint32 gss_duplicate_name (
        OM_uint32 *              minor_status,
        const gss_name_t         src_name,
        gss_name_t *             dest_name)

   Purpose:

   Create an exact duplicate of the existing internal name src_name.  The
   new dest_name will be independent of src_name (i.e. src_name and
   dest_name must both be released, and the release of one shall not affect
   the validity of the other).

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   src_name          gss_name_t, read
                     internal name to be duplicated.

   dest_name         gss_name_t, modify
                     The resultant copy of <src_name>.
                     Storage associated with this name must
                     be freed by the application after use
                     with a call to gss_release_name().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_NAME    The src_name parameter was ill-formed.









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   7.13.  gss_export_name

   OM_uint32 gss_export_name (
        OM_uint32 *              minor_status,
        const gss_name_t         input_name,
        gss_buffer_t             exported_name)

   Purpose:

   To produce a canonical contiguous string representation of a mechanism
   name (MN), suitable for direct comparison (e.g. with memcmp) for use in
   authorization functions (e.g. matching entries in an access-control
   list).

   The <input_name> parameter must specify a valid MN (i.e. an internal
   name generated by gss_accept_sec_context or by gss_canonicalize_name).


   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   input_name        gss_name_t, read
                     The MN to be exported

   exported_name     gss_buffer_t, octet-string, modify
                     The canonical contiguous string form of
                     <input_name>.  Storage associated with
                     this string must freed by the application
                     after use with gss_release_buffer().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NAME_NOT_MN The provided internal name was not a mechanism name.

   GSS_S_BAD_NAME    The provide internal name was ill-formed.

   GSS_S_BAD_NAMETYPE The internal name was of a type not supported by the
                     GSSAPI implementation.












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   7.14.  gss_export_sec_context

   OM_uint32 gss_export_sec_context (
        OM_uint32  *             minor_status,
        gss_ctx_id_t *           context_handle,
        gss_buffer_t             interprocess_token)

   Purpose:

   Provided to support the sharing of work between multiple processes.
   This routine will typically be used by the context-acceptor, in an
   application where a single process receives incoming connection requests
   and accepts security contexts over them, then passes the established
   context to one or more other processes for message exchange.
   gss_export_sec_context() deactivates the security context for the
   calling process and creates an interprocess token which, when passed to
   gss_import_sec_context in another process, will re-activate the context
   in the second process. Only a single instantiation of a given context
   may be active at any one time; a subsequent attempt by a context
   exporter to access the exported security context will fail.

   The implementation may constrain the set of processes by which the
   interprocess token may be imported, either as a function of local
   security policy, or as a result of implementation decisions.  For
   example, some implementations may constrain contexts to be passed only
   between processes that run under the same account, or which are part of
   the same process group.

   The interprocess token may contain security-sensitive information (for
   example cryptographic keys).  While mechanisms are encouraged to either
   avoid placing such sensitive information within interprocess tokens, or
   to encrypt the token before returning it to the application, in a
   typical object-library GSSAPI implementation this may not be possible.
   Thus the application must take care to protect the interprocess token,
   and ensure that any process to which the token is transferred is
   trustworthy.

   If creation of the interprocess token is succesful, the implementation
   shall deallocate all process-wide resources associated with the security
   context, and set the context_handle to GSS_C_NO_CONTEXT.  In the event
   of an error that makes it impossible to complete the export of the
   security context, the implementation must not return an interprocess
   token, and should strive to leave the security context referenced by the
   context_handle parameter untouched.  If this is impossible, it is
   permissible for the implementation to delete the security context,
   providing it also sets the context_handle parameter to GSS_C_NO_CONTEXT.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code



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   context_handle    gss_ctx_id_t, modify
                     context handle identifying the context to transfer.

   interprocess_token   buffer, opaque, modify
                        token to be transferred to target process.
                        Storage associated with this token must be
                        freed by the application after use with a
                        call to gss_release_buffer().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_CONTEXT_EXPIRED The context has expired

   GSS_S_NO_CONTEXT  The context was invalid

   GSS_S_UNAVAILABLE The operation is not supported.







   7.15.  gss_get_mic

   OM_uint32 gss_get_mic (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        gss_qop_t                qop_req,
        const gss_buffer_t       message_buffer,
        gss_buffer_t             msg_token)

   Purpose:

   Generates a cryptographic MIC for the supplied message, and places the
   MIC in a token for transfer to the peer application.  The qop_req
   parameter allows a choice between several cryptographic algorithms, if
   supported by the chosen mechanism.

   Parameters:

   minor_status      Integer, modify
                     Implementation specific status code.

   context_handle    gss_ctx_id_t, read
                     identifies the context on which the message
                     will be sent




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   qop_req           gss_qop_t, read, optional
                     Specifies requested quality of protection.
                     Callers are encouraged, on portability grounds,
                     to accept the default quality of protection
                     offered by the chosen mechanism, which may be
                     requested by specifying GSS_C_QOP_DEFAULT for
                     this parameter.  If an unsupported protection
                     strength is requested, gss_get_mic will return a
                     major_status of GSS_S_BAD_QOP.

   message_buffer    buffer, opaque, read
                     message to be protected

   msg_token         buffer, opaque, modify
                     buffer to receive token.  The application must
                     free storage associated with this buffer after
                     use with a call to gss_release_buffer().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_CONTEXT_EXPIRED The context has already expired

   GSS_S_NO_CONTEXT  The context_handle parameter did not identify a valid
                     context

   GSS_S_BAD_QOP     The specified QOP is not supported by the mechanism.







   7.16.  gss_import_name

   OM_uint32 gss_import_name (
        OM_uint32 *              minor_status,
        const gss_buffer_t       input_name_buffer,
        const gss_OID            input_name_type,
        gss_name_t *             output_name)

   Purpose:

   Convert a contiguous string name to internal form.  In general, the
   internal name returned (via the <output_name> parameter) will not be an
   MN; the exception to this is if the <input_name_type> indicates that the
   contiguous string provided via the <input_name_buffer> parameter is of
   type GSS_C_NT_EXPORT_NAME, in which case the returned internal name will
   be an MN for the mechanism that exported the name.




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   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   input_name_buffer  buffer, octet-string, read
                     buffer containing contiguous string name to convert

   input_name_type   Object ID, read, optional
                     Object ID specifying type of printable
                     name.  Applications may specify either
                     GSS_C_NO_OID to use a mechanism-specific
                     default printable syntax, or an OID registered
                     by the GSS-API implementation to name a
                     specific namespace.

   output_name       gss_name_t, modify
                     returned name in internal form.  Storage
                     associated with this name must be freed
                     by the application after use with a call
                     to gss_release_name().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_NAMETYPE The input_name_type was unrecognized

   GSS_S_BAD_NAME    The input_name parameter could not be interpreted as a
                     name of the specified type








   7.17.  gss_import_sec_context

   OM_uint32 gss_import_sec_context (
        OM_uint32  *             minor_status,
        const gss_buffer_t       interprocess_token,
        gss_ctx_id_t *           context_handle)

   Purpose:

   Allows a process to import a security context established by another
   process.  A given interprocess token may be imported only once.  See
   gss_export_sec_context.




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   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   interprocess_token  buffer, opaque, modify
                     token received from exporting process

   context_handle    gss_ctx_id_t, modify
                     context handle of newly reactivated context.
                     Resources associated with this context handle
                     must be released by the application after use
                     with a call to gss_delete_sec_context().


   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion.

   GSS_S_NO_CONTEXT  The token did not contain a valid context reference.

   GSS_S_DEFECTIVE_TOKEN The token was invalid.

   GSS_S_UNAVAILABLE The operation is unavailable.

   GSS_S_UNAUTHORIZED Local policy prevents the import of this context by
                     the current process..







   7.18.  gss_indicate_mechs

   OM_uint32 gss_indicate_mechs (
        OM_uint32 *              minor_status,
        gss_OID_set *            mech_set)

   Purpose:

   Allows an application to determine which underlying security mechanisms
   are available.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.




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   mech_set          set of Object IDs, modify
                     set of implementation-supported mechanisms.
                     The returned gss_OID_set value will be a
                     dynamically-allocated OID set, that should
                     be released by the caller after use with a
                     call to gss_release_oid_set().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion







   7.19.  gss_init_sec_context

   OM_uint32 gss_init_sec_context (
        OM_uint32 *              minor_status,
        const gss_cred_id_t      initiator_cred_handle,
        gss_ctx_id_t *           context_handle,
        const gss_name_t         target_name,
        const gss_OID            mech_type,
        OM_uint32                req_flags,
        OM_uint32                time_req,
        const gss_channel_bindings_t
                                 input_chan_bindings,
        const gss_buffer_t       input_token
        gss_OID *                actual_mech_type,
        gss_buffer_t             output_token,
        OM_uint32 *              ret_flags,
        OM_uint32 *              time_rec )

   Purpose:

   Initiates the establishment of a security context between the
   application and a remote peer.  Initially, the input_token parameter
   should be specified either as GSS_C_NO_BUFFER, or as a pointer to a
   gss_buffer_desc object whose length field contains the value zero.  The
   routine may return a output_token which should be transferred to the
   peer application, where the peer application will present it to
   gss_accept_sec_context.  If no token need be sent, gss_init_sec_context
   will indicate this by setting the length field of the output_token
   argument to zero.  To complete the context establishment, one or more
   reply tokens may be required from the peer application; if so,
   gss_init_sec_context will return a status containing the supplementary
   information bit GSS_S_CONTINUE_NEEDED.  In this case,
   gss_init_sec_context should be called again when the reply token is
   received from the peer application, passing the reply token to
   gss_init_sec_context via the input_token parameters.



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   Portable applications should be constructed to use the token length and
   return status to determine whether a token needs to be sent or waited
   for.  Thus a typical portable caller should always invoke
   gss_init_sec_context within a loop:

       int context_established = 0;
       gss_ctx_id_t context_hdl = GSS_C_NO_CONTEXT;
       ...
       input_token->length = 0;

       while (!context_established) {
          maj_stat = gss_init_sec_context(&min_stat,
                                          cred_hdl,
                                          &context_hdl,
                                          target_name,
                                          desired_mech,
                                          desired_services,
                                          desired_time,
                                          input_bindings,
                                          input_token,
                                          &actual_mech,
                                          output_token,
                                          &actual_services,
                                          &actual_time);
          if (GSS_ERROR(maj_stat)) {
             report_error(maj_stat, min_stat);
          };
          if (output_token->length != 0) {
             send_token_to_peer(output_token);
             gss_release_buffer(&min_stat,
                                output_token)
          };
          if (GSS_ERROR(maj_stat)) {
             if (context_hdl != GSS_C_NO_CONTEXT)
                gss_delete_sec_context(&min_stat,
                                       &context_hdl,
                                       GSS_C_NO_BUFFER);
             break;
          };
          if (maj_stat & GSS_S_CONTINUE_NEEDED) {
             receive_token_from_peer(input_token);
          } else {
             context_established = 1;
          };
       };

   Whenever the routine returns a major status that includes the value
   GSS_S_CONTINUE_NEEDED, the context is not fully established and the
   following restrictions apply to the output parameters:





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     (a) The value returned via the time_rec parameter is undefined

     (b) Unless the accompanying ret_flags parameter contains the bit
         GSS_C_PROT_READY_FLAG, indicating that per-message services may be
         applied in advance of a successful completion status, the value
         returned via the actual_mech_type parameter is undefined until the
         routine returns a major status value of GSS_S_COMPLETE.

     (c) The values of the GSS_C_DELEG_FLAG, GSS_C_MUTUAL_FLAG,
         GSS_C_REPLAY_FLAG, GSS_C_SEQUENCE_FLAG, GSS_C_CONF_FLAG,
         GSS_C_INTEG_FLAG and GSS_C_ANON_FLAG bits returned via the
         ret_flags parameter should contain the values that the
         implementation expects would be valid if context establishment
         were to succeed.  In particular, if the application has requested
         a service such as delegation or anonymous authentication via the
         req_flags argument, and such a service is unavailable from the
         underlying mechanism, gss_init_sec_context should generate a token
         that will not provide the service, and indicate via the ret_flags
         argument that the service will not be supported.  The application
         may choose to abort the context establishment by calling
         gss_delete_sec_context (if it cannot continue in the absence of
         the service), or it may choose to transmit the token and continue
         context establishment (if the service was merely desired but not
         mandatory).

         The values of the GSS_C_PROT_READY_FLAG and GSS_C_TRANS_FLAG bits
         within ret_flags should indicate the actual state at the time
         gss_init_sec_context returns, whether or not the context is fully
         established.

         Although this requires that GSSAPI implementations set the
         GSS_C_PROT_READY_FLAG in the final ret_flags returned to a caller
         (i.e. when accompanied by a GSS_S_COMPLETE status code),
         applications should not rely on this behavior as the flag was not
         defined in Version 1 of the GSSAPI. Instead, applications should
         be prepared to use per-message services after a successful context
         establishment, according to the GSS_C_INTEG_FLAG and
         GSS_C_CONF_FLAG values.

         All other bits within the ret_flags argument should be set to
         zero.

   If the initial call of gss_init_sec_context() fails, the implementation
   should not create a context object, and should leave the value of the
   context_handle parameter set to GSS_C_NO_CONTEXT to indicate this.  In
   the event of a failure on a subsequent call, the implementation is
   permitted to delete the "half-built" security context (in which case it
   should set the context_handle parameter to GSS_C_NO_CONTEXT), but the
   preferred behavior is to leave the security context untouched for the
   application to delete (using gss_delete_sec_context).




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   Parameters:

   minor_status      Integer,  modify
                     Mechanism specific status code.

   initiator_cred_handle  gss_cred_id_t, read, optional
                     handle for credentials claimed.  Supply
                     GSS_C_NO_CREDENTIAL to act as a default
                     initiator principal.  If no default
                     initiator is defined, the function will
                     return GSS_S_NO_CRED.

   context_handle    gss_ctx_id_t, read/modify
                     context handle for new context.  Supply
                     GSS_C_NO_CONTEXT for first call; use value
                     returned by first call in continuation calls.
                     Resources associated with this context-handle
                     must be released by the application after use
                     with a call to gee_delete_sec_context().

   target_name       gss_name_t, read
                     Name of target

   mech_type         OID, read, optional
                     Object ID of desired mechanism. Supply
                     GSS_C_NO_OID to obtain an implementation
                     specific default

   req_flags         bit-mask, read
                     Contains various independent flags, each of
                     which requests that the context support a
                     specific service option.  Symbolic
                     names are provided for each flag, and the
                     symbolic names corresponding to the required
                     flags should be logically-ORed
                     together to form the bit-mask value.  The
                     flags are:

                     GSS_C_DELEG_FLAG
                           True - Delegate credentials to remote peer
                           False - Don't delegate
                     GSS_C_MUTUAL_FLAG
                           True - Request that remote peer
                                  authenticate itself
                           False - Authenticate self to remote peer
                                   only
                     GSS_C_REPLAY_FLAG
                           True - Enable replay detection for
                                  messages protected with gss_wrap
                                  or gss_get_mic
                           False - Don't attempt to detect
                                   replayed messages


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                     GSS_C_SEQUENCE_FLAG
                           True - Enable detection of out-of-sequence
                                  protected messages
                           False - Don't attempt to detect
                                   out-of-sequence messages
                     GSS_C_ANON_FLAG
                           True - Do not reveal the initiator's
                                  identity to the acceptor.
                           False - Authenticate normally.

   time_req          Integer, read, optional
                     Desired number of seconds for which context
                     should remain valid.  Supply 0 to request a
                     default validity period.

   input_chan_bindings  channel bindings, read, optional
                     Application-specified bindings.  Allows
                     application to securely bind channel
                     identification information to the security
                     context.  Specify GSS_C_NO_CHANNEL_BINDINGS
                     if channel bindings are not used.

   input_token       buffer, opaque, read, optional (see text)
                     Token received from peer application.
                     Supply GSS_C_NO_BUFFER, or a pointer to
                     a buffer containing the value GSS_C_EMPTY_BUFFER
                     on initial call.

   actual_mech_type  OID, modify, optional
                     Actual mechanism used.  The OID returned via
                     this parameter will be a pointer to static
                     storage that should be treated as read-only;
                     In particular the application should not attempt
                     to free it.  Specify NULL if not required.

   output_token      buffer, opaque, modify
                     token to be sent to peer application.  If
                     the length field of the returned buffer is
                     zero, no token need be sent to the peer
                     application.  Storage associated with this
                     buffer must be freed by the application
                     after use with a call to gss_release_buffer().

   ret_flags         bit-mask, modify, optional
                     Contains various independent flags, each of which
                     indicates that the context supports a specific
                     service option.  Specify NULL if not
                     required.  Symbolic names are provided
                     for each flag, and the symbolic names
                     corresponding to the required flags should be



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                     logically-ANDed with the ret_flags value to test
                     whether a given option is supported by the
                     context.  The flags are:

                     GSS_C_DELEG_FLAG
                           True - Credentials were delegated to
                                  the remote peer
                           False - No credentials were delegated
                     GSS_C_MUTUAL_FLAG
                           True - Remote peer has been asked to
                                  authenticated itself
                           False - Remote peer has not been asked to
                                   authenticate itself
                     GSS_C_REPLAY_FLAG
                           True - replay of protected messages
                                  will be detected
                           False - replayed messages will not be
                                   detected
                     GSS_C_SEQUENCE_FLAG
                           True - out-of-sequence protected
                                  messages will be detected
                           False - out-of-sequence messages will
                                   not be detected
                     GSS_C_CONF_FLAG
                           True - Confidentiality service may be
                                  invoked by calling gss_wrap routine
                           False - No confidentiality service (via
                                   gss_wrap) available. gss_wrap will
                                   provide message encapsulation,
                                   data-origin authentication and
                                   integrity services only.
                     GSS_C_INTEG_FLAG
                           True - Integrity service may be invoked by
                                  calling either gss_get_mic or gss_wrap
                                  routines.
                           False - Per-message integrity service
                                   unavailable.
                     GSS_C_ANON_FLAG
                           True - The initiator's identity has not been
                                  revealed, and will not be revealed if
                                  any emitted token is passed to the
                                  acceptor.
                           False - The initiator's identity has been or
                                   will be authenticated normally.
                     GSS_C_PROT_READY_FLAG
                           True - Protection services (as specified
                                  by the states of the GSS_C_CONF_FLAG
                                  and GSS_C_INTEG_FLAG) are available for
                                  use if the accompanying major status
                                  return value is either GSS_S_COMPLETE or
                                  GSS_S_CONTINUE_NEEDED.



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                           False - Protection services (as specified
                                   by the states of the GSS_C_CONF_FLAG
                                   and GSS_C_INTEG_FLAG) are available
                                   only if the accompanying major status
                                   return value is GSS_S_COMPLETE.
                     GSS_C_TRANS_FLAG
                           True - The resultant security context may
                                  be transferred to other processes via
                                  a call to gss_export_sec_context().
                           False - The security context is not
                                   transferrable.
                     All other bits should be set to zero.

   time_rec          Integer, modify, optional
                     number of seconds for which the context
                     will remain valid. If the implementation does
                     not support context expiration, the value
                     GSS_C_INDEFINITE will be returned.  Specify
                     NULL if not required.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_CONTINUE_NEEDED Indicates that a token from the peer application
                     is required to complete the context, and that
                     gss_init_sec_context must be called again with that
                     token.

   GSS_S_DEFECTIVE_TOKEN Indicates that consistency checks performed on the
                     input_token failed

   GSS_S_DEFECTIVE_CREDENTIAL Indicates that consistency checks performed
                     on the credential failed.

   GSS_S_NO_CRED     The supplied credentials were not valid for context
                     initiation, or the credential handle did not reference
                     any credentials.

   GSS_S_CREDENTIALS_EXPIRED The referenced credentials have expired

   GSS_S_BAD_BINDINGS The input_token contains different channel bindings
                     to those specified via the input_chan_bindings
                     parameter

   GSS_S_BAD_SIG     The input_token contains an invalid MIC, or a MIC that
                     could not be verified

   GSS_S_OLD_TOKEN   The input_token was too old.  This is a fatal error
                     during context establishment




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   GSS_S_DUPLICATE_TOKEN The input_token is valid, but is a duplicate of a
                     token already processed.  This is a fatal error during
                     context establishment.

   GSS_S_NO_CONTEXT  Indicates that the supplied context handle did not
                     refer to a valid context

   GSS_S_BAD_NAMETYPE The provided target_name parameter contained an
                     invalid or unsupported type of name

   GSS_S_BAD_NAME    The provided target_name parameter was ill-formed.

   GSS_S_BAD_MECH    The specified mechanism is not supported by the
                     provided credential, or is unrecognized by the
                     implementation.







   7.20.  gss_inquire_context

   OM_uint32 gss_inquire_context (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        gss_name_t *             src_name,
        gss_name_t *             targ_name,
        OM_uint32 *              lifetime_rec,
        gss_OID *                mech_type,
        OM_uint32 *              ctx_flags,
        int *                    locally_initiated,
        int *                    open )

   Purpose:

   Obtains information about a security context.  The caller must already
   have obtained a handle that refers to the context, although the context
   need not be fully established.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   context_handle    gss_ctx_id_t, read
                     A handle that refers to the security context.

   src_name          gss_name_t, modify, optional
                     The name of the context initiator.



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                     If the context was established using anonymous
                     authentication, and if the application invoking
                     gss_inquire_context is the context acceptor,
                     an anonymous name will be returned.  Storage
                     associated with this name must be freed by the
                     application after use with a call to
                     gss_release_name().  Specify NULL if not
                     required.

   targ_name         gss_name_t, modify, optional
                     The name of the context acceptor.
                     Storage associated with this name must be
                     freed by the application after use with a call
                     to gss_release_name().  Specify NULL if not
                     Specify NULL if not required.

   lifetime_rec      Integer, modify, optional
                     The number of seconds for which the context
                     will remain valid.  If the context has
                     expired, this parameter will be set to zero.
                     If the implementation does not support
                     context expiration, the value
                     GSS_C_INDEFINITE will be returned.  Specify
                     NULL if not required.

   mech_type         gss_OID, modify, optional
                     The security mechanism providing the
                     context.  The returned OID will be a
                     pointer to static storage that should
                     be treated as read-only by the application;
                     in particular the application should not
                     attempt to free it.  Specify NULL if not
                     required.

   ctx_flags         bit-mask, modify, optional
                     Contains various independent flags, each of
                     which indicates that the context supports
                     (or is expected to support, if ctx_open is
                     false) a specific service option.  If not
                     needed, specify NULL.  Symbolic names are
                     provided for each flag, and the symbolic names
                     corresponding to the required flags
                     should be logically-ANDed with the ret_flags
                     value to test whether a given option is
                     supported by the context.  The flags are:

                     GSS_C_DELEG_FLAG
                           True - Credentials were delegated from
                                  the initiator to the acceptor.
                           False - No credentials were delegated



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                     GSS_C_MUTUAL_FLAG
                           True - The acceptor was authenticated
                                  to the initiator
                           False - The acceptor did not authenticate
                                   itself.
                     GSS_C_REPLAY_FLAG
                           True - replay of protected messages
                                  will be detected
                           False - replayed messages will not be
                                   detected
                     GSS_C_SEQUENCE_FLAG
                           True - out-of-sequence protected
                                  messages will be detected
                           False - out-of-sequence messages will not
                                   be detected
                     GSS_C_CONF_FLAG
                           True - Confidentiality service may be invoked
                                  by calling gss_wrap routine
                           False - No confidentiality service (via
                                   gss_wrap) available. gss_wrap will
                                   provide message encapsulation,
                                   data-origin authentication and
                                   integrity services only.
                     GSS_C_INTEG_FLAG
                           True - Integrity service may be invoked by
                                  calling either gss_get_mic or gss_wrap
                                  routines.
                           False - Per-message integrity service
                                   unavailable.
                     GSS_C_ANON_FLAG
                           True - The initiator's identity will not
                                  be revealed to the acceptor.
                                  The src_name parameter (if
                                  requested) contains an anonymous
                                  internal name.
                           False - The initiator has been
                                   authenticated normally.
                     GSS_C_PROT_READY_FLAG
                           True - Protection services (as specified
                                  by the states of the GSS_C_CONF_FLAG
                                  and GSS_C_INTEG_FLAG) are available
                                  for use.
                           False - Protection services (as specified
                                   by the states of the GSS_C_CONF_FLAG
                                   and GSS_C_INTEG_FLAG) are available
                                   only if the context is fully
                                   established (i.e. if the open parameter
                                   is non-zero).
                     GSS_C_TRANS_FLAG
                           True - The resultant security context may
                                  be transferred to other processes via
                                  a call to gss_export_sec_context().
                           False - The security context is not
                                   transferrable.

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   locally_initiated Boolean, modify
                     Non-zero if the invoking application is the
                     context initiator.
                     Specify NULL if not required.

   open              Boolean, modify
                     Non-zero if the context is fully established;
                     Zero if a context-establishment token
                     is expected from the peer application.
                     Specify NULL if not required.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NO_CONTEXT  The referenced context could not be accessed.

   GSS_S_CONTEXT_EXPIRED The context has expired.  If the lifetime_rec
                     parameter was requested, it will be set to 0.







   7.21.  gss_inquire_cred

   OM_uint32 gss_inquire_cred (
        OM_uint32  *             minor_status,
        const gss_cred_id_t      cred_handle,
        gss_name_t *             name,
        OM_uint32 *              lifetime,
        gss_cred_usage_t *       cred_usage,
        gss_OID_set *            mechanisms )

   Purpose:

   Obtains information about a credential.  The caller must already have
   obtained a handle that refers to the credential.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   cred_handle       gss_cred_id_t, read
                     A handle that refers to the target credential.
                     Specify GSS_C_NO_CREDENTIAL to inquire about
                     the default initiator principal.


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   name              gss_name_t, modify, optional
                     The name whose identity the credential asserts.
                     Storage associated with this name should be freed
                     by the application after use with a call to
                     gss_release_name().  Specify NULL if not required.

   lifetime          Integer, modify, optional
                     The number of seconds for which the credential
                     will remain valid.  If the credential has
                     expired, this parameter will be set to zero.
                     If the implementation does not support
                     credential expiration, the value
                     GSS_C_INDEFINITE will be returned.  Specify
                     NULL if not required.

   cred_usage        gss_cred_usage_t, modify, optional
                     How the credential may be used.  One of the
                     following:
                        GSS_C_INITIATE
                        GSS_C_ACCEPT
                        GSS_C_BOTH
                     Specify NULL if not required.

   mechanisms        gss_OID_set, modify, optional
                     Set of mechanisms supported by the credential.
                     Storage associated with this OID set must be
                     freed by the application after use with a call
                     to gss_release_oid_set().  Specify NULL if not
                     required.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NO_CRED     The referenced credentials could not be accessed.

   GSS_S_DEFECTIVE_CREDENTIAL The referenced credentials were invalid.

   GSS_S_CREDENTIALS_EXPIRED The referenced credentials have expired.  If
                     the lifetime parameter was not passed as NULL, it will
                     be set to 0.









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   7.22.  gss_inquire_cred_by_mech

   OM_uint32 gss_inquire_cred_by_mech (
        OM_uint32 *              minor_status,
        const gss_cred_id_t      cred_handle,
        const gss_OID            mech_type,
        gss_name_t *             name,
        OM_uint32 *              initiator_lifetime,
        OM_uint32 *              acceptor_lifetime,
        gss_cred_usage_t *       cred_usage )

   Purpose:

   Obtains per-mechanism information about a credential.  The caller must
   already have obtained a handle that refers to the credential.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   cred_handle       gss_cred_id_t, read
                     A handle that refers to the target credential.
                     Specify GSS_C_NO_CREDENTIAL to inquire about
                     the default initiator principal.

   mech_type         gss_OID, read
                     The mechanism for which information should be
                     returned.

   name              gss_name_t, modify, optional
                     The name whose identity the credential asserts.
                     Storage associated with this name must be
                     freed by the application after use with a call
                     to gss_release_name().  Specify NULL if not
                     required.

   initiator_lifetime  Integer, modify, optional
                     The number of seconds for which the credential
                     will remain capable of initiating security contexts
                     under the specified mechanism.  If the credential
                     can no longer be used to initiate contexts, or if
                     the credential usage for this mechanism is
   GSS_C_ACCEPT,
                     this parameter will be set to zero.  If the
                     implementation does not support expiration of
                     initiator credentials, the value GSS_C_INDEFINITE
                     will be returned.  Specify NULL if not required.

   acceptor_lifetime Integer, modify, optional
                     The number of seconds for which the credential



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                     will remain capable of accepting security contexts
                     under the specified mechanism.  If the credential
                     can no longer be used to accept contexts, or if
                     the credential usage for this mechanism is
                     GSS_C_INITIATE, this parameter will be set to zero.
                     If the implementation does not support expiration
                     of acceptor credentials, the value GSS_C_INDEFINITE
                     will be returned.  Specify NULL if not required.

   cred_usage        gss_cred_usage_t, modify, optional
                     How the credential may be used with the specified
                     mechanism.  One of the following:
                        GSS_C_INITIATE
                        GSS_C_ACCEPT
                        GSS_C_BOTH
                     Specify NULL if not required.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NO_CRED     The referenced credentials could not be accessed.

   GSS_S_DEFECTIVE_CREDENTIAL The referenced credentials were invalid.

   GSS_S_CREDENTIALS_EXPIRED The referenced credentials have expired.  If
                     the lifetime parameter was not passed as NULL, it will
                     be set to 0.







   7.23.  gss_inquire_mechs_for_name

   OM_uint32 gss_inquire_mechs_for_name (
        OM_uint32 *              minor_status,
        const gss_name_t         input_name,
        gss_OID_set *            mech_types )

   Purpose:

   Returns the set of mechanisms supported by the GSSAPI implementation
   that may be able to process the specified name.

   Each mechanism returned will recognize at least one element within the
   name.  It is permissible for this routine to be implemented within a
   mechanism-independent GSSAPI layer, using the type information contained
   within the presented name, and based on registration information



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   provided by individual mechanism implementations.  This means that the
   returned mech_types set may indicate that a particular mechanism will
   understand the name when in fact it would refuse to accept the name as
   input to gss_canonicalize_name, gss_init_sec_context, gss_acquire_cred
   or gss_add_cred (due to some property of the specific name, as opposed
   to the name type).  Thus this routine should be used only as a pre-
   filter for a call to a subsequent mechanism-specific routine.



   Parameters:

   minor_status      Integer, modify
                     Implementation specific status code.

   input_name        gss_name_t, read
                     The name to which the inquiry relates.

   mech_types        gss_OID_set, modify
                     Set of mechanisms that may support the
                     specified name.  The returned OID set
                     must be freed by the caller after use
                     with a call to gss_release_oid_set().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_NAME    The input_name parameter was ill-formed.

   GSS_S_BAD_NAMETYPE The input_name parameter contained an invalid or
                     unsupported type of name






   7.24.  gss_inquire_names_for_mech

   OM_uint32 gss_inquire_names_for_mech (
        OM_uint32 *              minor_status,
        const gss_OID            mechanism,
        gss_OID_set *            name_types)

   Purpose:

   Returns the set of nametypes supported by the specified mechanism.






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   Parameters:

   minor_status      Integer, modify
                     Implementation specific status code.

   mechanism         gss_OID, read
                     The mechanism to be interrogated.

   name_types        gss_OID_set, modify
                     Set of name-types supported by the specified
                     mechanism.  The returned OID set must be
                     freed by the application after use with a
                     call to gss_release_oid_set().

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion







   7.25.  gss_process_context_token

   OM_uint32 gss_process_context_token (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        const gss_buffer_t       token_buffer)

   Purpose:

   Provides a way to pass a token to the security service.  Used with
   tokens emitted by gss_delete_sec_context.  Note that mechanisms are
   encouraged to perform local deletion, and not emit tokens from
   gss_delete_sec_context.  This routine, therefore, is primarily for
   backwards compatibility with V1 applications.

   Parameters:

   minor_status      Integer, modify
                     Implementation specific status code.

   context_handle    gss_ctx_id_t, read
                     context handle of context on which token is to
                     be processed

   token_buffer      buffer, opaque, read
                     token to process




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   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_DEFECTIVE_TOKEN Indicates that consistency checks performed on the
                     token failed

   GSS_S_NO_CONTEXT  The context_handle did not refer to a valid context







   7.26.  gss_release_buffer

   OM_uint32 gss_release_buffer (
        OM_uint32 *              minor_status,
        gss_buffer_t             buffer)

   Purpose:

   Free storage associated with a buffer.  The storage must have been
   allocated by a GSS-API routine.  In addition to freeing the associated
   storage, the routine will zero the length field in the descriptor to
   which the buffer parameter refers.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   buffer            buffer, modify
                     The storage associated with the buffer will be
                     deleted.  The gss_buffer_desc object will not
                     be freed, but its length field will be zeroed.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion













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   7.27.  gss_release_cred

   OM_uint32 gss_release_cred (
        OM_uint32 *              minor_status,
        gss_cred_id_t *          cred_handle)

   Purpose:

   Informs GSS-API that the specified credential handle is no longer
   required by the application, and frees associated resources.

   Parameters:

   cred_handle       gss_cred_id_t, modify, optional
                     Opaque handle identifying credential
                     to be released.  If GSS_C_NO_CREDENTIAL
                     is supplied, the routine will complete
                     successfully, but will do nothing.

   minor_status      Integer, modify
                     Mechanism specific status code.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NO_CRED     Credentials could not be accessed.







   7.28.  gss_release_name

   OM_uint32 gss_release_name (
        OM_uint32 *              minor_status,
        gss_name_t *             name)

   Purpose:

   Free GSSAPI-allocated storage by associated with an internal-form name.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   name              gss_name_t, modify
                     The name to be deleted



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   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_BAD_NAME    The name parameter did not contain a valid name







   7.29.  gss_release_oid_set

   OM_uint32 gss_release_oid_set (
        OM_uint32 *              minor_status,
        gss_OID_set *            set)

   Purpose:

   Free storage associated with a GSSAPI-generated gss_OID_set object.  The
   set parameter must refer to an OID-set that was returned from a GSSAPI
   routine.  gss_release_oid_set() will free the storage associated with
   each individual member OID, the OID set's elements array, and the
   gss_OID_set_desc.


   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   set               Set of Object IDs, modify
                     The storage associated with the gss_OID_set
                     will be deleted.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion















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   7.30.  gss_test_oid_set_member

   OM_uint32 gss_test_oid_set_member (
        OM_uint32  *             minor_status,
        const gss_OID            member,
        const gss_OID_set        set,
        int *                    present)

   Purpose:

   Interrogate an Object Identifier set to determine whether a specified
   Object Identifier is a member.  This routine is intended to be used with
   OID sets returned by gss_indicate_mechs(), gss_acquire_cred(), and
   gss_inquire_cred(), but will also work with user-generated sets.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   member            Object ID, read
                     The object identifier whose presence
                     is to be tested.

   set               Set of Object ID, read
                     The Object Identifier set.

   present           Boolean, modify
                     non-zero if the specified OID is a member
                     of the set, zero if not.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion







   7.31.  gss_unwrap

   OM_uint32 gss_unwrap (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        const gss_buffer_t       input_message_buffer,
        gss_buffer_t             output_message_buffer,
        int *                    conf_state,
        gss_qop_t *              qop_state)




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   Purpose:

   Converts a message previously protected by gss_wrap back to a usable
   form, verifying the embedded MIC.  The conf_state parameter indicates
   whether the message was encrypted; the qop_state parameter indicates the
   strength of protection that was used to provide the confidentiality and
   integrity services.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   context_handle    gss_ctx_id_t, read
                     Identifies the context on which the message
                     arrived

   input_message_buffer  buffer, opaque, read
                     protected message

   output_message_buffer  buffer, opaque, modify
                     Buffer to receive unwrapped message.
                     Storage associated with this buffer must
                     be freed by the application after use use
                     with a call to gss_release_buffer().

   conf_state        boolean, modify, optional
                     Non-zero - Confidentiality and integrity protection
                                were used
                     Zero - Integrity service only was used
                     Specify NULL if not required

   qop_state         gss_qop_t, modify, optional
                     Quality of protection gained from MIC.
                     Specify NULL if not required

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_DEFECTIVE_TOKEN The token failed consistency checks

   GSS_S_BAD_SIG     The MIC was incorrect

   GSS_S_DUPLICATE_TOKEN The token was valid, and contained a correct MIC
                     for the message, but it had already been processed

   GSS_S_OLD_TOKEN   The token was valid, and contained a correct MIC for
                     the message, but it is too old to check for
                     duplication.




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   GSS_S_UNSEQ_TOKEN The token was valid, and contained a correct MIC for
                     the message, but has been verified out of sequence; a
                     later token has already been received.

   GSS_S_GAP_TOKEN   The token was valid, and contained a correct MIC for
                     the message, but has been verified out of sequence;
                     an earlier expected token has not yet been received.

   GSS_S_CONTEXT_EXPIRED The context has already expired

   GSS_S_NO_CONTEXT  The context_handle parameter did not identify a valid
                     context







   7.32.  gss_verify_mic

   OM_uint32 gss_verify_mic (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        const gss_buffer_t       message_buffer,
        const gss_buffer_t       token_buffer,
        gss_qop_t *              qop_state)

   Purpose:

   Verifies that a cryptographic MIC, contained in the token parameter,
   fits the supplied message.  The qop_state parameter allows a message
   recipient to determine the strength of protection that was applied to
   the message.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   context_handle    gss_ctx_id_t, read
                     Identifies the context on which the message
                     arrived

   message_buffer    buffer, opaque, read
                     Message to be verified

   token_buffer      buffer, opaque, read
                     Token associated with message




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   qop_state         gss_qop_t, modify, optional
                     quality of protection gained from MIC
                     Specify NULL if not required

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_DEFECTIVE_TOKEN The token failed consistency checks

   GSS_S_BAD_SIG     The MIC was incorrect

   GSS_S_DUPLICATE_TOKEN The token was valid, and contained a correct MIC
                     for the message, but it had already been processed

   GSS_S_OLD_TOKEN   The token was valid, and contained a correct MIC for
                     the message, but it is too old to check for
                     duplication.

   GSS_S_UNSEQ_TOKEN The token was valid, and contained a correct MIC for
                     the message, but has been verified out of sequence; a
                     later token has already been received.

   GSS_S_GAP_TOKEN   The token was valid, and contained a correct MIC for
                     the message, but has been verified out of sequence;
                     an earlier expected token has not yet been received.

   GSS_S_CONTEXT_EXPIRED The context has already expired

   GSS_S_NO_CONTEXT  The context_handle parameter did not identify a valid
                     context







   7.33.  gss_wrap

   OM_uint32 gss_wrap (
        OM_uint32 *              minor_status,
        const gss_ctx_id_t       context_handle,
        int                      conf_req_flag,
        gss_qop_t                qop_req
        const gss_buffer_t       input_message_buffer,
        int *                    conf_state,
        gss_buffer_t             output_message_buffer )







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   Purpose:

   Attaches a cryptographic MIC and optionally encrypts the specified
   input_message.  The output_message contains both the MIC and the
   message.  The qop_req parameter allows a choice between several
   cryptographic algorithms, if supported by the chosen mechanism.

   Since some application-level protocols may wish to use tokens emitted by
   gss_wrap() to provide "secure framing", implementations should support
   the wrapping of zero-length messages.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code.

   context_handle    gss_ctx_id_t, read
                     Identifies the context on which the message
                     will be sent

   conf_req_flag     boolean, read
                     Non-zero - Both confidentiality and integrity
                                services are requested
                     Zero - Only integrity service is requested

   qop_req           gss_qop_t, read, optional
                     Specifies required quality of protection.  A
                     mechanism-specific default may be requested by
                     setting qop_req to GSS_C_QOP_DEFAULT.  If an
                     unsupported protection strength is requested,
                     gss_wrap will return a major_status of
                     GSS_S_BAD_QOP.

   input_message_buffer  buffer, opaque, read
                     Message to be protected

   conf_state        boolean, modify, optional
                     Non-zero - Confidentiality, data origin
                                authentication and integrity
                                services have been applied
                     Zero - Integrity and data origin services only
                            has been applied.
                     Specify NULL if not required

   output_message_buffer  buffer, opaque, modify
                     Buffer to receive protected message.
                     Storage associated with this message must
                     be freed by the application after use with
                     a call to gss_release_buffer().

   Function value:   GSS status code



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   GSS_S_COMPLETE    Successful completion

   GSS_S_CONTEXT_EXPIRED The context has already expired

   GSS_S_NO_CONTEXT  The context_handle parameter did not identify a valid
                     context

   GSS_S_BAD_QOP     The specified QOP is not supported by the mechanism.







   7.34.  gss_wrap_size_limit

   OM_uint32 gss_wrap_size_limit (
        OM_uint32  *             minor_status,
        const gss_ctx_id_t       context_handle,
        int                      conf_req_flag,
        gss_qop_t                qop_req,
        OM_uint32                req_output_size,
        OM_uint32 *              max_input_size)

   Purpose:

   Allows an application to determine the maximum message size that, if
   presented to gss_wrap with the same conf_req_flag and qop_req
   parameters, will result in an output token containing no more than
   req_output_size bytes.

   This call is intended for use by applications that communicate over
   protocols that impose a maximum message size.  It enables the
   application to fragment messages prior to applying protection.

   Successful completion of this call does not guarantee that gss_wrap will
   be able to protect a message of length max_input_size bytes, since this
   ability may depend on the availability of system resources at the time
   that gss_wrap is called.  However, if the implementation itself imposes
   an upper limit on the length of messages that may be processed by
   gss_wrap, the implementation should not return a value via
   max_input_bytes that is greater than this length.

   Parameters:

   minor_status      Integer, modify
                     Mechanism specific status code

   context_handle    gss_ctx_id_t, read
                     A handle that refers to the security over



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                     which the messages will be sent.

   conf_req_flag     Boolean, read
                     Indicates whether gss_wrap will be asked
                     to apply confidentiality protection in
                     addition to integrity protection.  See
                     the routine description for gss_wrap
                     for more details.

   qop_req           gss_qop_t, read
                     Indicates the level of protection that
                     gss_wrap will be asked to provide.  See
                     the routine description for gss_wrap for
                     more details.

   req_output_size   Integer, read
                     The desired maximum size for tokens emitted
                     by gss_wrap.

   max_input_size    Integer, modify
                     The maximum input message size that may
                     be presented to gss_wrap in order to
                     guarantee that the emitted token shall
                     be no larger than req_output_size bytes.

   Function value:   GSS status code

   GSS_S_COMPLETE    Successful completion

   GSS_S_NO_CONTEXT  The referenced context could not be accessed.

   GSS_S_CONTEXT_EXPIRED The context has expired.

   GSS_S_BAD_QOP     The specified QOP is not supported by the mechanism.




















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   APPENDIX A. GSS-API C header file gssapi.h

   C-language GSS-API implementations should include a copy of the
   following header-file.

   #ifndef GSSAPI_H_
   #define GSSAPI_H_



   /*
    * First, include stddef.h to get size_t defined.
    */
   #include <stddef.h>

   /*
    * If the platform supports the xom.h header file, it should be
    * included here.
    */
   #include <xom.h>



   /*
    * Now define the three implementation-dependent types.
    */
   typedef <platform-specific> gss_ctx_id_t;
   typedef <platform-specific> gss_cred_id_t;
   typedef <platform-specific> gss_name_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 <platform-specific> gss_uint32;


   #ifdef OM_STRING
   /*
    * We have included the xom.h header file.  Verify that OM_uint32
    * is defined correctly.
    */

   #if sizeof(gss_uint32) != sizeof(OM_uint32)
   #error Incompatible definition of OM_uint32 from xom.h
   #endif

   typedef OM_object_identifier gss_OID_desc, *gss_OID;

   #else



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   /*
    * 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

   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
    */
   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



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   /*
    * 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_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}



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   /*
    * 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 define GSS_C_QOP_DEFAULT to be either zero
    * (as done here) to mean "default protection", or 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 0xfffffffful

   /*
    * The implementation must reserve static storage for a
    * gss_OID_desc object containing the value
    * {10, (void *)"\x2a\x86\x48\x86\xf7\x12"
    *              "\x01\x02\x01\x01"},
    * corresponding to an object-identifier value of
    * {iso(1) member-body(2) United States(840) mit(113554)
    *  infosys(1) gssapi(2) generic(1) user_name(1)}.  The constant
    * GSS_C_NT_USER_NAME should be initialized to point
    * to that gss_OID_desc.
    */
   extern gss_OID GSS_C_NT_USER_NAME;

   /*
    * The implementation must reserve static storage for a
    * gss_OID_desc object containing the value
    * {10, (void *)"\x2a\x86\x48\x86\xf7\x12"
    *              "\x01\x02\x01\x02"},
    * corresponding to an object-identifier value of
    * {iso(1) member-body(2) United States(840) mit(113554)
    *  infosys(1) gssapi(2) generic(1) machine_uid_name(2)}.
    * The constant GSS_C_NT_MACHINE_UID_NAME should be
    * initialized to point to that gss_OID_desc.
    */
   extern gss_OID GSS_C_NT_MACHINE_UID_NAME;

   /*



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    * The implementation must reserve static storage for a
    * gss_OID_desc object containing the value
    * {10, (void *)"\x2a\x86\x48\x86\xf7\x12"
    *              "\x01\x02\x01\x03"},
    * corresponding to an object-identifier value of
    * {iso(1) member-body(2) United States(840) mit(113554)
    *  infosys(1) gssapi(2) generic(1) string_uid_name(3)}.
    * The constant GSS_C_NT_STRING_UID_NAME should be
    * initialized to point to that gss_OID_desc.
    */
   extern gss_OID GSS_C_NT_STRING_UID_NAME;

   /*
    * The implementation must reserve static storage for a
    * gss_OID_desc object containing the value
    * {6, (void *)"\x2b\x06\x01\x05\x06\x02"},
    * corresponding to an object-identifier value of
    * {1(iso), 3(org), 6(dod), 1(internet), 5(security),
    * 6(nametypes), 2(gss-host-based-services)}.  The constant
    * GSS_C_NT_HOSTBASED_SERVICE should be initialized to point
    * to that gss_OID_desc.
    */
   extern gss_OID GSS_C_NT_HOSTBASED_SERVICE;

   /*
    * The implementation must reserve static storage for a
    * gss_OID_desc object containing the value
    * {6, (void *)"\x2b\x06\01\x05\x06\x03"},
    * corresponding to an object identifier value of
    * {1(iso), 3(org), 6(dod), 1(internet), 5(security),
    * 6(nametypes), 3(gss-anonymous-name)}.  The constant
    * and GSS_C_NT_ANONYMOUS should be initialized to point
    * to that gss_OID_desc.
    */
   extern gss_OID GSS_C_NT_ANONYMOUS;



   /*
    * The implementation must reserve static storage for a
    * gss_OID_desc object containing the value
    * {6, (void *)"\x2b\x06\x01\x05\x06\x04"},
    * corresponding to an object-identifier value of
    * {1(iso), 3(org), 6(dod), 1(internet), 5(security),
    * 6(nametypes), 4(gss-api-exported-name)}.  The constant
    * GSS_C_NT_EXPORT_NAME should be initialized to point
    * to that gss_OID_desc.
    */
   extern gss_OID GSS_C_NT_EXPORT_NAME;





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   /* 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 0377ul
   #define GSS_C_ROUTINE_ERROR_MASK 0377ul
   #define GSS_C_SUPPLEMENTARY_MASK 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 \
                                (1ul << GSS_C_CALLING_ERROR_OFFSET)
   #define GSS_S_CALL_INACCESSIBLE_WRITE \
                                (2ul << GSS_C_CALLING_ERROR_OFFSET)
   #define GSS_S_CALL_BAD_STRUCTURE \
                                (3ul << GSS_C_CALLING_ERROR_OFFSET)

   /*
    * Routine errors:
    */
   #define GSS_S_BAD_MECH (1ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_BAD_NAME (2ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_BAD_NAMETYPE (3ul << GSS_C_ROUTINE_ERROR_OFFSET)



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   #define GSS_S_BAD_BINDINGS (4ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_BAD_STATUS (5ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_BAD_SIG (6ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_BAD_MIC GSS_S_BAD_SIG
   #define GSS_S_NO_CRED (7ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_NO_CONTEXT (8ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_DEFECTIVE_TOKEN (9ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_DEFECTIVE_CREDENTIAL (10ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_CREDENTIALS_EXPIRED (11ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_CONTEXT_EXPIRED (12ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_FAILURE (13ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_BAD_QOP (14ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_UNAUTHORIZED (15ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_UNAVAILABLE (16ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_DUPLICATE_ELEMENT (17ul << GSS_C_ROUTINE_ERROR_OFFSET)
   #define GSS_S_NAME_NOT_MN (18ul << GSS_C_ROUTINE_ERROR_OFFSET)

   /*
    * Supplementary info bits:
    */
   #define GSS_S_CONTINUE_NEEDED (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 0))
   #define GSS_S_DUPLICATE_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 1))
   #define GSS_S_OLD_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 2))
   #define GSS_S_UNSEQ_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 3))
   #define GSS_S_GAP_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 4))


   /*
    * Finally, function prototypes for the GSS-API routines.
    */

   OM_uint32 gss_acquire_cred
              (OM_uint32 *,             /*  minor_status */
               const gss_name_t,        /* desired_name */
               OM_uint32,               /* time_req */
               const gss_OID_set,       /* desired_mechs */
               gss_cred_usage_t,        /* cred_usage */
               gss_cred_id_t *,         /* output_cred_handle */
               gss_OID_set *,           /* actual_mechs */
               OM_uint32 *              /* time_rec */
              );

   OM_uint32 gss_release_cred
              (OM_uint32 *,             /* minor_status */
               gss_cred_id_t *          /* cred_handle */
              );

   OM_uint32 gss_init_sec_context
              (OM_uint32 *,             /* minor_status */
               const gss_cred_id_t,     /* initiator_cred_handle */
               gss_ctx_id_t *,          /* context_handle */



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               const gss_name_t,        /* target_name */
               const gss_OID,           /* mech_type */
               OM_uint32,               /* req_flags */
               OM_uint32,               /* time_req */
               const gss_channel_bindings_t,
                                        /* input_chan_bindings */
               const gss_buffer_t,      /* input_token */
               gss_OID *,               /* actual_mech_type */
               gss_buffer_t,            /* output_token */
               OM_uint32 *,             /* ret_flags */
               OM_uint32 *              /* time_rec */
              );

   OM_uint32 gss_accept_sec_context
              (OM_uint32 *,             /* minor_status */
               gss_ctx_id_t *,          /* context_handle */
               const gss_cred_id_t,     /* acceptor_cred_handle */
               const gss_buffer_t,      /* input_token_buffer */
               const gss_channel_bindings_t,
                                        /* input_chan_bindings */
               gss_name_t *,            /* src_name */
               gss_OID *,               /* mech_type */
               gss_buffer_t,            /* output_token */
               OM_uint32 *,             /* ret_flags */
               OM_uint32 *,             /* time_rec */
               gss_cred_id_t *          /* delegated_cred_handle */
              );

   OM_uint32 gss_process_context_token
              (OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               const gss_buffer_t       /* token_buffer */
              );

   OM_uint32 gss_delete_sec_context
              (OM_uint32 *,             /* minor_status */
               gss_ctx_id_t *,          /* context_handle */
               gss_buffer_t             /* output_token */
              );

   OM_uint32 gss_context_time
              (OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               OM_uint32 *              /* time_rec */
              );

   OM_uint32 gss_get_mic
              (OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               gss_qop_t,               /* qop_req */
               const gss_buffer_t,      /* message_buffer */



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               gss_buffer_t             /* message_token */
              );


   OM_uint32 gss_verify_mic
              (OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               const gss_buffer_t,      /* message_buffer */
               const gss_buffer_t,      /* token_buffer */
               gss_qop_t *              /* qop_state */
              );

   OM_uint32 gss_wrap
              (OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               int,                     /* conf_req_flag */
               gss_qop_t,               /* qop_req */
               const gss_buffer_t,      /* input_message_buffer */
               int *,                   /* conf_state */
               gss_buffer_t             /* output_message_buffer */
              );


   OM_uint32 gss_unwrap
              (OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               const gss_buffer_t,      /* input_message_buffer */
               gss_buffer_t,            /* output_message_buffer */
               int *,                   /* conf_state */
               gss_qop_t *              /* qop_state */
              );



   OM_uint32 gss_display_status
              (OM_uint32 *,             /* minor_status */
               OM_uint32,               /* status_value */
               int,                     /* status_type */
               const gss_OID,           /* mech_type */
               OM_uint32 *,             /* message_context */
               gss_buffer_t             /* status_string */
              );

   OM_uint32 gss_indicate_mechs
              (OM_uint32 *,             /* minor_status */
               gss_OID_set *            /* mech_set */
              );

   OM_uint32 gss_compare_name
              (OM_uint32 *,             /* minor_status */
               const gss_name_t,        /* name1 */



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               const gss_name_t,        /* name2 */
               int *                    /* name_equal */
              );

   OM_uint32 gss_display_name
              (OM_uint32 *,             /* minor_status */
               const gss_name_t,        /* input_name */
               gss_buffer_t,            /* output_name_buffer */
               gss_OID *                /* output_name_type */
              );

   OM_uint32 gss_import_name
              (OM_uint32 *,             /* minor_status */
               const gss_buffer_t,      /* input_name_buffer */
               const gss_OID,           /* input_name_type */
               gss_name_t *             /* output_name */
              );

   OM_uint32 gss_export_name
              (OM_uint32  *,            /* minor_status */
               const gss_name_t,        /* input_name */
               gss_buffer_t             /* exported_name */
              );

   OM_uint32 gss_release_name
              (OM_uint32 *,             /* minor_status */
               gss_name_t *             /* input_name */
              );

   OM_uint32 gss_release_buffer
              (OM_uint32 *,             /* minor_status */
               gss_buffer_t             /* buffer */
              );

   OM_uint32 gss_release_oid_set
              (OM_uint32 *,             /* minor_status */
               gss_OID_set *            /* set */
              );

   OM_uint32 gss_inquire_cred
              (OM_uint32 *,             /* minor_status */
               const gss_cred_id_t,     /* cred_handle */
               gss_name_t *,            /* name */
               OM_uint32 *,             /* lifetime */
               gss_cred_usage_t *,      /* cred_usage */
               gss_OID_set *            /* mechanisms */
              );

   OM_uint32 gss_inquire_context (
               OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */



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               gss_name_t *,            /* src_name */
               gss_name_t *,            /* targ_name */
               OM_uint32 *,             /* lifetime_rec */
               gss_OID *,               /* mech_type */
               OM_uint32 *,             /* ctx_flags */
               int *,                   /* locally_initiated */
               int *                    /* open */
              );

   OM_uint32 gss_wrap_size_limit (
               OM_uint32 *,             /* minor_status */
               const gss_ctx_id_t,      /* context_handle */
               int,                     /* conf_req_flag */
               gss_qop_t,               /* qop_req */
               OM_uint32,               /* req_output_size */
               OM_uint32 *              /* max_input_size */
              );


   OM_uint32 gss_add_cred (
               OM_uint32 *,             /* minor_status */
               const gss_cred_id_t,     /* input_cred_handle */
               const gss_name_t,        /* desired_name */
               const gss_OID,           /* desired_mech */
               gss_cred_usage_t,        /* cred_usage */
               OM_uint32,               /* initiator_time_req */
               OM_uint32,               /* acceptor_time_req */
               gss_cred_id_t *,         /* output_cred_handle */
               gss_OID_set *,           /* actual_mechs */
               OM_uint32 *,             /* initiator_time_rec */
               OM_uint32 *              /* acceptor_time_rec */
              );


   OM_uint32 gss_inquire_cred_by_mech (
               OM_uint32 *,             /* minor_status */
               const gss_cred_id_t,     /* cred_handle */
               const gss_OID,           /* mech_type */
               gss_name_t *,            /* name */
               OM_uint32 *,             /* initiator_lifetime */
               OM_uint32 *,             /* acceptor_lifetime */
               gss_cred_usage_t *       /* cred_usage */
              );

   OM_uint32 gss_export_sec_context (
               OM_uint32 *,             /* minor_status */
               gss_ctx_id_t *,          /* context_handle */
               gss_buffer_t             /* interprocess_token */
              );

   OM_uint32 gss_import_sec_context (



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               OM_uint32 *,             /* minor_status */
               const gss_buffer_t,      /* interprocess_token */
               gss_ctx_id_t *           /* context_handle */
              );

   OM_uint32 gss_create_empty_oid_set (
               OM_uint32 *,             /* minor_status */
               gss_OID_set *            /* oid_set */
              );

   OM_uint32 gss_add_oid_set_member (
               OM_uint32 *,             /* minor_status */
               const gss_OID,           /* member_oid */
               gss_OID_set *            /* oid_set */
              );

   OM_uint32 gss_test_oid_set_member (
               OM_uint32 *,             /* minor_status */
               const gss_OID,           /* member */
               const gss_OID_set,       /* set */
               int *                    /* present */
              );

   OM_uint32 gss_inquire_names_for_mech (
               OM_uint32 *,             /* minor_status */
               const gss_OID,           /* mechanism */
               gss_OID_set *            /* name_types */
              );

   OM_uint32 gss_inquire_mechs_for_name (
               OM_uint32 *,             /* minor_status */
               const gss_name_t,        /* input_name */
               gss_OID_set *            /* mech_types */
              );

   OM_uint32 gss_canonicalize_name (
               OM_uint32 *,             /* minor_status */
               const gss_name_t,        /* input_name */
               const gss_OID,           /* mech_type */
               gss_name_t *             /* output_name */
              );

   OM_uint32 gss_duplicate_name (
               OM_uint32 *,             /* minor_status */
               const gss_name_t,        /* src_name */
               gss_name_t *             /* dest_name */
              );

   /*
    * The following routines are obsolete variants of gss_get_mic,
    * gss_verify_mic, gss_wrap and gss_unwrap.  They should be



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    * provided by GSSAPI V2 implementations for backwards
    * compatibility with V1 applications.  Distinct entrypoints
    * (as opposed to #defines) should be provided, both to allow
    * GSSAPI V1 applications to link against GSSAPI V2 implementations,
    * and to retain the slight parameter type differences between the
    * obsolete versions of these routines and their current forms.
    */

   OM_uint32 gss_sign
              (OM_uint32 *,        /* minor_status */
               gss_ctx_id_t,       /* context_handle */
               int,                /* qop_req */
               gss_buffer_t,       /* message_buffer */
               gss_buffer_t        /* message_token */
              );


   OM_uint32 gss_verify
              (OM_uint32 *,        /* minor_status */
               gss_ctx_id_t,       /* context_handle */
               gss_buffer_t,       /* message_buffer */
               gss_buffer_t,       /* token_buffer */
               int *               /* qop_state */
              );

   OM_uint32 gss_seal
              (OM_uint32 *,        /* minor_status */
               gss_ctx_id_t,       /* context_handle */
               int,                /* conf_req_flag */
               int,                /* qop_req */
               gss_buffer_t,       /* input_message_buffer */
               int *,              /* conf_state */
               gss_buffer_t        /* output_message_buffer */
              );


   OM_uint32 gss_unseal
              (OM_uint32 *,        /* minor_status */
               gss_ctx_id_t,       /* context_handle */
               gss_buffer_t,       /* input_message_buffer */
               gss_buffer_t,       /* output_message_buffer */
               int *,              /* conf_state */
               int *               /* qop_state */
              );




   #endif /* GSSAPI_H_ */





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   APPENDIX B. Additional constraints for application binary portability

   The purpose of this C-bindings document is to encourage source-level
   portability of applications across GSS-API implementations on different
   platforms and atop different mechanisms.  Additional goals that have not
   been explicitly addressed by this document are link-time and run-time
   portability.

   Link-time portability provides the ability to compile an application
   against one implementation of GSS-API, and then link it against a
   different implementation on the same platform.  It is a stricter
   requirement than source-level portability.

   Run-time portability differs from link-time portability only on those
   platforms that implement dynamically loadable GSS-API implementations,
   but do not offer load-time symbol resolution.  On such platforms, run-
   time portability is a stricter requirement than link-time portability,
   and will typically include the precise placement of the various GSS-API
   routines within library entrypoint vectors.

   Individual platforms will impose their own rules that must be followed
   to achieve link-time (and run-time, if different) portability.  In order
   to ensure either form of binary portability, an ABI specification must
   be written for GSS-API implementations on that platform.  However, it is
   recognized that there are some issues that are likely to be common to
   all such ABI specifications. This appendix is intended to be a
   repository for such common issues, and contains some suggestions that
   individual ABI specifications may choose to reference.  Since machine
   architectures vary greatly, it may not be possible or desirable to
   follow these suggestions on all platforms.

   B.1.  Pointers

   While ANSI-C provides a single pointer type for each declared type, plus
   a single (void *) type, some platforms (notably those using segmented
   memory architectures) augment this with various modified pointer types
   (e.g. far pointers, near pointers).  These language bindings assume
   ANSI-C, and thus do not address such non-standard implementations.
   GSS-API implementations for such platforms must choose an appropriate
   memory model, and should use it consistently throughout.  For example,
   if a memory model is chosen that requires the use of far pointers when
   passing routine parameters, then far pointers should also be used within
   the structures defined by GSS-API.

   B.2.  Internal structure alignment

   GSS-API defines several data-structures containing differently-sized
   fields.  An ABI specification should include a detailed description of
   how the fields of such structures are aligned, and if there is any
   internal padding in these data structures.  The use of compiler defaults
   for the platform is recommended.



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   B.3.  Handle types

   The C bindings specify that the gss_cred_id_t and gss_ctx_id_t types
   should be implemented as either pointer or arithmetic types, and that if
   pointer types are used, care should be taken to ensure that two handles
   may be compared with the == operator.  Note that ANSI-C does not
   guarantee that two pointer values may be compared with the == operator
   unless either the two pointers point to members of a single array, or at
   least one of the pointers contains a NULL value.

   For binary portability, additional constraints are required.  The
   following is an attempt at defining platform-independent constraints.

     (a) The size of the handle type must be the same as sizeof(void *),
         using the appropriate memory model.

     (b) The == operator for the chosen type must be a simple bit-wise
         comparison.  That is, for two in-memory handle objects h1 and h2,
         the boolean value of the expression

              (h1 == h2)

         should always be the same as the boolean value of the expression

              (memcmp(&h1, &h2, sizeof(h1)) == 0)

     (c) The actual use of the type (void *) for handle types is
         discouraged, not for binary portability reasons, but since it
         effectively disables much of the compile-time type-checking that
         the compiler can otherwise perform, and is therefore not
         "programmer-friendly".  If a pointer implementation is desired,
         and if the platform's implementation of pointers permits, the
         handles should be implemented as pointers to distinct
         implementation-defined types.

   B.4.  The gss_name_t type

   The gss_name_t type, representing the internal name object, should be
   implemented as a pointer type.  The use of the (void *) type is
   discouraged as it does not allow the compiler to perform strong type-
   checking.  However, the pointer type chosen should be of the same size
   as the (void *) type.  Provided this rule is obeyed, ABI specifications
   need not further constrain the implementation of gss_name_t objects.

   B.5.  The int and size_t types

   Some platforms may support differently sized implementations of the
   "int" and "size_t" types, perhaps chosen through compiler switches, and
   perhaps dependent on memory model.  An ABI specification for such a
   platform should include required implementations for these types. It is
   recommended that the default implementation (for the chosen memory



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   model, if appropriate) is chosen.

   B.6.  Procedure-calling conventions

   Some platforms support a variety of different binary conventions for
   calling procedures.  Such conventions cover things like the format of
   the stack frame, the order in which the routine parameters are pushed
   onto the stack, whether or not a parameter count is pushed onto the
   stack, whether some argument(s) or return values are to be passed in
   registers, and whether the called routine or the caller is responsible
   for removing the stack frame on return.  For such platforms, an ABI
   specification should specify which calling convention is to be used for
   GSSAPI implementations.


   REFERENCES

   [GSSAPI]    J. Linn, "Generic Security Service Application Program
               Interface, Version 2", Internet-Draft draft-ietf-cat-gssv2-
               08, 26 August 1996.  (This Internet-Draft, like all other
               Internet-Drafts, is not an archival document and is subject
               to change or deletion.  It is available at the time of this
               writing by anonymous ftp from ds.internic.net, directory
               internet-drafts. Would-be readers should check for successor
               Internet-Draft versions or Internet RFCs before relying on
               this document.)

   [XOM]       OSI Object Management API Specification, Version 2.0 t",
               X.400 API Association & X/Open Company Limited, August 24,
               1990.  Specification of datatypes and routines for
               manipulating information objects.


   AUTHOR'S ADDRESS

   John Wray                       Internet email: Wray@tuxedo.enet.dec.com
   Digital Equipment Corporation                 Telephone: +1-508-486-5210
   550 King Street, LKG2-2/Z7
   Littleton, MA  01460
   USA














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