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RFC 2078

 
 
 

Generic Security Service Application Program Interface, Version 2

Part 2 of 3, p. 23 to 59
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2:  Interface Descriptions

   This section describes the GSS-API's service interface, dividing the
   set of calls offered into four groups. Credential management calls
   are related to the acquisition and release of credentials by
   principals. Context-level calls are related to the management of
   security contexts between principals. Per-message calls are related

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   to the protection of individual messages on established security
   contexts. Support calls provide ancillary functions useful to GSS-API
   callers. Table 2 groups and summarizes the calls in tabular fashion.

Table 2:  GSS-API Calls

   CREDENTIAL MANAGEMENT

   GSS_Acquire_cred             acquire credentials for use
   GSS_Release_cred             release credentials after use
   GSS_Inquire_cred             display information about
                                credentials
   GSS_Add_cred                 construct credentials incrementally
   GSS_Inquire_cred_by_mech     display per-mechanism credential
                                information

   CONTEXT-LEVEL CALLS

   GSS_Init_sec_context         initiate outbound security context
   GSS_Accept_sec_context       accept inbound security context
   GSS_Delete_sec_context       flush context when no longer needed
   GSS_Process_context_token    process received control token on
                                context
   GSS_Context_time             indicate validity time remaining on
                                      context
   GSS_Inquire_context          display information about context
   GSS_Wrap_size_limit          determine GSS_Wrap token size limit
   GSS_Export_sec_context       transfer context to other process
   GSS_Import_sec_context       import transferred context

   PER-MESSAGE CALLS

   GSS_GetMIC                   apply integrity check, receive as
                                token separate from message
   GSS_VerifyMIC                validate integrity check token
                                along with message
   GSS_Wrap                     sign, optionally encrypt,
                                encapsulate
   GSS_Unwrap                   decapsulate, decrypt if needed,
                                validate integrity check

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   SUPPORT CALLS

   GSS_Display_status           translate status codes to printable
                                form
   GSS_Indicate_mechs           indicate mech_types supported on
                                local system
   GSS_Compare_name             compare two names for equality
   GSS_Display_name             translate name to printable form
   GSS_Import_name              convert printable name to
                                normalized form
   GSS_Release_name             free storage of normalized-form
                                name
   GSS_Release_buffer           free storage of printable name
   GSS_Release_OID              free storage of OID object
   GSS_Release_OID_set          free storage of OID set object
   GSS_Create_empty_OID_set     create empty OID set
   GSS_Add_OID_set_member       add member to OID set
   GSS_Test_OID_set_member      test if OID is member of OID set
   GSS_OID_to_str               display OID as string
   GSS_Str_to_OID               construct OID from string
   GSS_Inquire_names_for_mech   indicate name types supported by
                                mechanism
   GSS_Inquire_mechs_for_name   indicates mechanisms supporting name
                                type
   GSS_Canonicalize_name        translate name to per-mechanism form
   GSS_Export_name              externalize per-mechanism name
   GSS_Duplicate_name           duplicate name object

2.1:  Credential management calls

   These GSS-API calls provide functions related to the management of
   credentials. Their characterization with regard to whether or not
   they may block pending exchanges with other network entities (e.g.,
   directories or authentication servers) depends in part on OS-specific
   (extra-GSS-API) issues, so is not specified in this document.

   The GSS_Acquire_cred() call is defined within the GSS-API in support
   of application portability, with a particular orientation towards
   support of portable server applications. It is recognized that (for
   certain systems and mechanisms) credentials for interactive users may
   be managed differently from credentials for server processes; in such
   environments, it is the GSS-API implementation's responsibility to
   distinguish these cases and the procedures for making this
   distinction are a local matter. The GSS_Release_cred()  call provides
   a means for callers to indicate to the GSS-API that use of a
   credentials structure is no longer required. The GSS_Inquire_cred()
   call allows callers to determine information about a credentials
   structure.  The GSS_Add_cred() call enables callers to append

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   elements to an existing credential structure, allowing iterative
   construction of a multi-mechanism credential. The
   GSS_Inquire_cred_by_mech() call enables callers to extract per-
   mechanism information describing a credentials structure.

2.1.1:  GSS_Acquire_cred call

   Inputs:

   o  desired_name INTERNAL NAME, -NULL requests locally-determined
      default

   o  lifetime_req INTEGER,-in seconds; 0 requests default

   o  desired_mechs SET OF OBJECT IDENTIFIER,-empty set requests
      system-selected default

   o  cred_usage INTEGER -0=INITIATE-AND-ACCEPT, 1=INITIATE-ONLY,
      2=ACCEPT-ONLY

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  output_cred_handle CREDENTIAL HANDLE,

   o  actual_mechs SET OF OBJECT IDENTIFIER,

   o  lifetime_rec INTEGER -in seconds, or reserved value for
      INDEFINITE

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that requested credentials were
      successfully established, for the duration indicated in
      lifetime_rec, suitable for the usage requested in cred_usage,
      for the set of mech_types indicated in actual_mechs, and that
      those credentials can be referenced for subsequent use with
      the handle returned in output_cred_handle.

   o  GSS_S_BAD_MECH indicates that a mech_type unsupported by the
      GSS-API implementation type was requested, causing the
      credential establishment operation to fail.

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   o  GSS_S_BAD_NAMETYPE indicates that the provided desired_name is
      uninterpretable or of a type unsupported by the applicable
      underlying GSS-API mechanism(s), so no credentials could be
      established for the accompanying desired_name.

   o  GSS_S_BAD_NAME indicates that the provided desired_name is
      inconsistent in terms of internally-incorporated type specifier
      information, so no credentials could be established for the
      accompanying desired_name.

   o  GSS_S_FAILURE indicates that credential establishment failed
      for reasons unspecified at the GSS-API level, including lack
      of authorization to establish and use credentials associated
      with the identity named in the input desired_name argument.

   GSS_Acquire_cred()  is used to acquire credentials so that a
   principal can (as a function of the input cred_usage parameter)
   initiate and/or accept security contexts under the identity
   represented by the desired_name input argument. On successful
   completion, the returned output_cred_handle result provides a handle
   for subsequent references to the acquired credentials.  Typically,
   single-user client processes requesting that default credential
   behavior be applied for context establishment purposes will have no
   need to invoke this call.

   A caller may provide the value NULL for desired_name, signifying a
   request for credentials corresponding to a principal identity
   selected by default for the caller. The procedures used by GSS-API
   implementations to select the appropriate principal identity in
   response to such a request are local matters. It is possible that
   multiple pre-established credentials may exist for the same principal
   identity (for example, as a result of multiple user login sessions)
   when GSS_Acquire_cred() is called; the means used in such cases to
   select a specific credential are local matters.  The input
   lifetime_req argument to GSS_Acquire_cred() may provide useful
   information for local GSS-API implementations to employ in making
   this disambiguation in a manner which will best satisfy a caller's
   intent.

   The lifetime_rec result indicates the length of time for which the
   acquired credentials will be valid, as an offset from the present. A
   mechanism may return a reserved value indicating INDEFINITE if no
   constraints on credential lifetime are imposed.  A caller of
   GSS_Acquire_cred()  can request a length of time for which acquired
   credentials are to be valid (lifetime_req argument), beginning at the
   present, or can request credentials with a default validity interval.
   (Requests for postdated credentials are not supported within the
   GSS-API.) Certain mechanisms and implementations may bind in

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   credential validity period specifiers at a point preliminary to
   invocation of the GSS_Acquire_cred() call (e.g., in conjunction with
   user login procedures). As a result, callers requesting non-default
   values for lifetime_req must recognize that such requests cannot
   always be honored and must be prepared to accommodate the use of
   returned credentials with different lifetimes as indicated in
   lifetime_rec.

   The caller of GSS_Acquire_cred()  can explicitly specify a set of
   mech_types which are to be accommodated in the returned credentials
   (desired_mechs argument), or can request credentials for a system-
   defined default set of mech_types. Selection of the system-specified
   default set is recommended in the interests of application
   portability. The actual_mechs return value may be interrogated by the
   caller to determine the set of mechanisms with which the returned
   credentials may be used.

2.1.2:  GSS_Release_cred call

   Input:

   o  cred_handle CREDENTIAL HANDLE - NULL specifies that
      the credential elements used when default credential behavior
      is requested be released.

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the credentials referenced by the
      input cred_handle were released for purposes of subsequent
      access by the caller. The effect on other processes which may
      be authorized shared access to such credentials is a local
      matter.

   o  GSS_S_NO_CRED indicates that no release operation was
      performed, either because the input cred_handle was invalid or
      because the caller lacks authorization to access the
      referenced credentials.

   o  GSS_S_FAILURE indicates that the release operation failed for
      reasons unspecified at the GSS-API level.

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   Provides a means for a caller to explicitly request that credentials
   be released when their use is no longer required. Note that system-
   specific credential management functions are also likely to exist,
   for example to assure that credentials shared among processes are
   properly deleted when all affected processes terminate, even if no
   explicit release requests are issued by those processes. Given the
   fact that multiple callers are not precluded from gaining authorized
   access to the same credentials, invocation of GSS_Release_cred()
   cannot be assumed to delete a particular set of credentials on a
   system-wide basis.

2.1.3:  GSS_Inquire_cred call

   Input:

   o  cred_handle CREDENTIAL HANDLE -NULL specifies that the
      credential elements used when default credential behavior is
      requested are to be queried

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  cred_name INTERNAL NAME,

   o  lifetime_rec INTEGER -in seconds, or reserved value for
      INDEFINITE

   o  cred_usage INTEGER, -0=INITIATE-AND-ACCEPT, 1=INITIATE-ONLY,
      2=ACCEPT-ONLY

   o  mech_set SET OF OBJECT IDENTIFIER

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the credentials referenced by the
      input cred_handle argument were valid, and that the output
      cred_name, lifetime_rec, and cred_usage values represent,
      respectively, the credentials' associated principal name,
      remaining lifetime, suitable usage modes, and supported
      mechanism types.

   o  GSS_S_NO_CRED indicates that no information could be returned
      about the referenced credentials, either because the input
      cred_handle was invalid or because the caller lacks
      authorization to access the referenced credentials.

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   o  GSS_S_DEFECTIVE_CREDENTIAL indicates that the referenced
      credentials are invalid.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the referenced
      credentials have expired.

   o  GSS_S_FAILURE indicates that the operation failed for
      reasons unspecified at the GSS-API level.

   The GSS_Inquire_cred() call is defined primarily for the use of those
   callers which request use of default credential behavior rather than
   acquiring credentials explicitly with GSS_Acquire_cred().  It enables
   callers to determine a credential structure's associated principal
   name, remaining validity period, usability for security context
   initiation and/or acceptance, and supported mechanisms.

   For a multi-mechanism credential, the returned "lifetime" specifier
   indicates the shortest lifetime of any of the mechanisms' elements in
   the credential (for either context initiation or acceptance
   purposes).

   GSS_Inquire_cred() should indicate INITIATE-AND-ACCEPT for
   "cred_usage" if both of the following conditions hold:

      (1) there exists in the credential an element which allows context
      initiation using some mechanism

      (2) there exists in the credential an element which allows context
      acceptance using some mechanism (allowably, but not necessarily,
      one of the same mechanism(s) qualifying for (1)).

   If condition (1) holds but not condition (2), GSS_Inquire_cred()
   should indicate INITIATE-ONLY for "cred_usage".  If condition (2)
   holds but not condition (1), GSS_Inquire_cred() should indicate
   ACCEPT-ONLY for "cred_usage".

   Callers requiring finer disambiguation among available combinations
   of lifetimes, usage modes, and mechanisms should call the
   GSS_Inquire_cred_by_mech() routine, passing that routine one of the
   mech OIDs returned by GSS_Inquire_cred().

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2.1.4:  GSS_Add_cred call

   Inputs:

   o  input_cred_handle CREDENTIAL HANDLE - handle to credential
      structure created with prior GSS_Acquire_cred() or
      GSS_Add_cred() call, or NULL to append elements to the set
      which are applied for the caller when default credential
      behavior is specified.

   o  desired_name INTERNAL NAME - NULL requests locally-determined
      default

   o  initiator_time_req INTEGER - in seconds; 0 requests default

   o  acceptor_time_req INTEGER - in seconds; 0 requests default

   o  desired_mech OBJECT IDENTIFIER

   o  cred_usage INTEGER - 0=INITIATE-AND-ACCEPT, 1=INITIATE-ONLY,
       2=ACCEPT-ONLY

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  output_cred_handle CREDENTIAL HANDLE, - NULL to request that
      credential elements be added "in place" to the credential
      structure  identified by input_cred_handle, non-NULL pointer
      to request that a new credential structure and handle be created.

   o  actual_mechs SET OF OBJECT IDENTIFIER,

   o  initiator_time_rec INTEGER - in seconds, or reserved value for
      INDEFINITE

   o  acceptor_time_rec INTEGER - in seconds, or reserved value for
      INDEFINITE

   o  cred_usage INTEGER, -0=INITIATE-AND-ACCEPT, 1=INITIATE-ONLY,
      2=ACCEPT-ONLY

   o  mech_set SET OF OBJECT IDENTIFIER -- full set of mechanisms
      supported by resulting credential.

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   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the credentials referenced by
      the input_cred_handle argument were valid, and that the
      resulting credential from GSS_Add_cred() is valid for the
      durations indicated in initiator_time_rec and acceptor_time_rec,
      suitable for the usage requested in cred_usage, and for the
      mechanisms indicated in actual_mechs.

   o  GSS_S_DUPLICATE_ELEMENT indicates that the input desired_mech
      specified a mechanism for which the referenced credential
      already contained a credential element with overlapping
      cred_usage and validity time specifiers.

   o  GSS_S_BAD_MECH indicates that the input desired_mech specified
      a mechanism unsupported by the GSS-API implementation, causing
      the GSS_Add_cred() operation to fail.

   o  GSS_S_BAD_NAMETYPE indicates that the provided desired_name
      is uninterpretable or of a type unsupported by the applicable
      underlying GSS-API mechanism(s), so the GSS_Add_cred() operation
      could not be performed for that name.

   o  GSS_S_BAD_NAME indicates that the provided desired_name is
      inconsistent in terms of internally-incorporated type specifier
      information, so the GSS_Add_cred() operation could not be
      performed for that name.

   o  GSS_S_NO_CRED indicates that the input_cred_handle referenced
      invalid or inaccessible credentials.

   o  GSS_S_FAILURE indicates that the operation failed for
      reasons unspecified at the GSS-API level, including lack of
      authorization to establish or use credentials representing
      the requested identity.

   GSS_Add_cred() enables callers to construct credentials iteratively
   by adding credential elements in successive operations, corresponding
   to different mechanisms.  This offers particular value in multi-
   mechanism environments, as the major_status and minor_status values
   returned on each iteration are individually visible and can therefore
   be interpreted unambiguously on a per-mechanism basis.

   The same input desired_name, or default reference, should be used on
   all GSS_Acquire_cred() and GSS_Add_cred() calls corresponding to a
   particular credential.

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2.1.5:  GSS_Inquire_cred_by_mech call

   Inputs:

   o  cred_handle CREDENTIAL HANDLE  -- NULL specifies that the
      credential elements used when default credential behavior is
      requested are to be queried

   o  mech_type OBJECT IDENTIFIER  -- specific mechanism for
      which credentials are being queried

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  cred_name INTERNAL NAME, -- guaranteed to be MN

   o  lifetime_rec_initiate INTEGER -- in seconds, or reserved value for
      INDEFINITE

   o  lifetime_rec_accept INTEGER -- in seconds, or reserved value for
      INDEFINITE

   o  cred_usage INTEGER, -0=INITIATE-AND-ACCEPT, 1=INITIATE-ONLY,
      2=ACCEPT-ONLY

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the credentials referenced by the
      input cred_handle argument were valid, that the mechanism
      indicated by the input mech_type was represented with elements
      within those credentials, and that the output cred_name,
      lifetime_rec_initiate, lifetime_rec_accept, and cred_usage values
      represent, respectively, the credentials' associated principal
      name, remaining lifetimes, and suitable usage modes.

   o  GSS_S_NO_CRED indicates that no information could be returned
      about the referenced credentials, either because the input
      cred_handle was invalid or because the caller lacks
      authorization to access the referenced credentials.

   o  GSS_S_DEFECTIVE_CREDENTIAL indicates that the referenced
      credentials are invalid.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the referenced
      credentials have expired.

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   o  GSS_S_BAD_MECH indicates that the referenced credentials do not
      contain elements for the requested mechanism.

   o  GSS_S_FAILURE indicates that the operation failed for reasons
      unspecified at the GSS-API level.

   The GSS_Inquire_cred_by_mech() call enables callers in multi-
   mechanism environments to acquire specific data about available
   combinations of lifetimes, usage modes, and mechanisms within a
   credential structure.  The lifetime_rec_initiate result indicates the
   available lifetime for context initiation purposes; the
   lifetime_rec_accept result indicates the available lifetime for
   context acceptance purposes.

2.2:  Context-level calls

   This group of calls is devoted to the establishment and management of
   security contexts between peers. A context's initiator calls
   GSS_Init_sec_context(),  resulting in generation of a token which the
   caller passes to the target. At the target, that token is passed to
   GSS_Accept_sec_context().  Depending on the underlying mech_type and
   specified options, additional token exchanges may be performed in the
   course of context establishment; such exchanges are accommodated by
   GSS_S_CONTINUE_NEEDED status returns from GSS_Init_sec_context()  and
   GSS_Accept_sec_context().

   Either party to an established context may invoke
   GSS_Delete_sec_context() to flush context information when a context
   is no longer required. GSS_Process_context_token()  is used to
   process received tokens carrying context-level control information.
   GSS_Context_time()  allows a caller to determine the length of time
   for which an established context will remain valid.
   GSS_Inquire_context() returns status information describing context
   characteristics. GSS_Wrap_size_limit() allows a caller to determine
   the size of a token which will be generated by a GSS_Wrap()
   operation.  GSS_Export_sec_context() and GSS_Import_sec_context()
   enable transfer of active contexts between processes on an end
   system.

2.2.1:  GSS_Init_sec_context call

   Inputs:

   o  claimant_cred_handle CREDENTIAL HANDLE, -NULL specifies "use
      default"

   o  input_context_handle CONTEXT HANDLE, -0 specifies "none assigned
      yet"

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   o  targ_name INTERNAL NAME,

   o  mech_type OBJECT IDENTIFIER, -NULL parameter specifies "use
      default"

   o  deleg_req_flag BOOLEAN,

   o  mutual_req_flag BOOLEAN,

   o  replay_det_req_flag BOOLEAN,

   o  sequence_req_flag BOOLEAN,

   o  anon_req_flag BOOLEAN,

   o  lifetime_req INTEGER,-0 specifies default lifetime

   o  chan_bindings OCTET STRING,

   o  input_token OCTET STRING-NULL or token received from target

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  output_context_handle CONTEXT HANDLE,

   o  mech_type OBJECT IDENTIFIER, -actual mechanism always
      indicated, never NULL

   o  output_token OCTET STRING, -NULL or token to pass to context
      target

   o  deleg_state BOOLEAN,

   o  mutual_state BOOLEAN,

   o  replay_det_state BOOLEAN,

   o  sequence_state BOOLEAN,

   o  anon_state BOOLEAN,

   o  trans_state BOOLEAN,

   o  prot_ready_state BOOLEAN, -- see Section 1.2.7

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   o  conf_avail BOOLEAN,

   o  integ_avail BOOLEAN,

   o  lifetime_rec INTEGER - in seconds, or reserved value for
      INDEFINITE

   This call may block pending network interactions for those mech_types
   in which an authentication server or other network entity must be
   consulted on behalf of a context initiator in order to generate an
   output_token suitable for presentation to a specified target.

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that context-level information was
      successfully initialized, and that the returned output_token
      will provide sufficient information for the target to perform
      per-message processing on the newly-established context.

   o  GSS_S_CONTINUE_NEEDED indicates that control information in the
      returned output_token must be sent to the target, and that a
      reply must be received and passed as the input_token argument
      to a continuation call to GSS_Init_sec_context(),  before
      per-message processing can be performed in conjunction with
      this context.

   o  GSS_S_DEFECTIVE_TOKEN indicates that consistency checks
      performed on the input_token failed, preventing further
      processing from being performed based on that token.

   o  GSS_S_DEFECTIVE_CREDENTIAL indicates that consistency checks
      performed on the credential structure referenced by
      claimant_cred_handle failed, preventing further processing from
      being performed using that credential structure.

   o  GSS_S_BAD_SIG indicates that the received input_token
      contains an incorrect integrity check, so context setup cannot
      be accomplished.

   o  GSS_S_NO_CRED indicates that no context was established,
      either because the input cred_handle was invalid, because the
      referenced credentials are valid for context acceptor use
      only, or because the caller lacks authorization to access the
      referenced credentials.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the credentials
      provided through the input claimant_cred_handle argument are no
      longer valid, so context establishment cannot be completed.

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   o  GSS_S_BAD_BINDINGS indicates that a mismatch between the
      caller-provided chan_bindings and those extracted from the
      input_token was detected, signifying a security-relevant
      event and preventing context establishment. (This result will
      be returned by GSS_Init_sec_context only for contexts where
      mutual_state is TRUE.)

   o  GSS_S_OLD_TOKEN indicates that the input_token is too old to
      be checked for integrity. This is a fatal error during context
      establishment.

   o  GSS_S_DUPLICATE_TOKEN indicates that the input token has a
      correct integrity check, but is a duplicate of a token already
      processed. This is a fatal error during context establishment.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided; this major status will
      be returned only for successor calls following GSS_S_CONTINUE_
      NEEDED status returns.

   o  GSS_S_BAD_NAMETYPE indicates that the provided targ_name is
      of a type uninterpretable or unsupported by the applicable
      underlying GSS-API mechanism(s), so context establishment
      cannot be completed.

   o  GSS_S_BAD_NAME indicates that the provided targ_name is
      inconsistent in terms of internally-incorporated type specifier
      information, so context establishment cannot be accomplished.

   o  GSS_S_BAD_MECH indicates receipt of a context establishment token
      or of a caller request specifying a mechanism unsupported by
      the local system or with the caller's active credentials

   o  GSS_S_FAILURE indicates that context setup could not be
      accomplished for reasons unspecified at the GSS-API level, and
      that no interface-defined recovery action is available.

   This routine is used by a context initiator, and ordinarily emits one
   (or, for the case of a multi-step exchange, more than one)
   output_token suitable for use by the target within the selected
   mech_type's protocol. Using information in the credentials structure
   referenced by claimant_cred_handle, GSS_Init_sec_context()
   initializes the data structures required to establish a security
   context with target targ_name. The targ_name may be any valid
   INTERNAL NAME; it need not be an MN. The claimant_cred_handle must
   correspond to the same valid credentials structure on the initial
   call to GSS_Init_sec_context()  and on any successor calls resulting
   from GSS_S_CONTINUE_NEEDED status returns; different protocol

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   sequences modeled by the GSS_S_CONTINUE_NEEDED facility will require
   access to credentials at different points in the context
   establishment sequence.

   The input_context_handle argument is 0, specifying "not yet
   assigned", on the first GSS_Init_sec_context()  call relating to a
   given context. If successful (i.e., if accompanied by major_status
   GSS_S_COMPLETE or GSS_S_CONTINUE_NEEDED), and only if successful, the
   initial GSS_Init_sec_context() call returns a non-zero
   output_context_handle for use in future references to this context.
   Once a non-zero output_context_handle has been returned, GSS-API
   callers should call GSS_Delete_sec_context() to release context-
   related resources if errors occur in later phases of context
   establishment, or when an established context is no longer required.

   When continuation attempts to GSS_Init_sec_context() are needed to
   perform context establishment, the previously-returned non-zero
   handle value is entered into the input_context_handle argument and
   will be echoed in the returned output_context_handle argument. On
   such continuation attempts (and only on continuation attempts) the
   input_token value is used, to provide the token returned from the
   context's target.

   The chan_bindings argument is used by the caller to provide
   information binding the security context to security-related
   characteristics (e.g., addresses, cryptographic keys) of the
   underlying communications channel. See Section 1.1.6 of this document
   for more discussion of this argument's usage.

   The input_token argument contains a message received from the target,
   and is significant only on a call to GSS_Init_sec_context()  which
   follows a previous return indicating GSS_S_CONTINUE_NEEDED
   major_status.

   It is the caller's responsibility to establish a communications path
   to the target, and to transmit any returned output_token (independent
   of the accompanying returned major_status value) to the target over
   that path. The output_token can, however, be transmitted along with
   the first application-provided input message to be processed by
   GSS_GetMIC() or GSS_Wrap() in conjunction with a successfully-
   established context.

   The initiator may request various context-level functions through
   input flags: the deleg_req_flag requests delegation of access rights,
   the mutual_req_flag requests mutual authentication, the
   replay_det_req_flag requests that replay detection features be
   applied to messages transferred on the established context, and the
   sequence_req_flag requests that sequencing be enforced. (See Section

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   1.2.3 for more information on replay detection and sequencing
   features.)  The anon_req_flag requests that the initiator's identity
   not be transferred within tokens to be sent to the acceptor.

   Not all of the optionally-requestable features will be available in
   all underlying mech_types. The corresponding return state values
   deleg_state, mutual_state, replay_det_state, and sequence_state
   indicate, as a function of mech_type processing capabilities and
   initiator-provided input flags, the set of features which will be
   active on the context.  The returned trans_state value indicates
   whether the context is transferable to other processes through use of
   GSS_Export_sec_context().  These state indicators' values are
   undefined unless either the routine's major_status indicates
   GSS_S_COMPLETE, or TRUE prot_ready_state is returned along with
   GSS_S_CONTINUE_NEEDED major_status; for the latter case, it is
   possible that additional features, not confirmed or indicated along
   with TRUE prot_ready_state, will be confirmed and indicated when
   GSS_S_COMPLETE is subsequently returned.

   The returned anon_state and prot_ready_state values are significant
   for both GSS_S_COMPLETE and GSS_S_CONTINUE_NEEDED major_status
   returns from GSS_Init_sec_context().  When anon_state is returned
   TRUE, this indicates that neither the current token nor its
   predecessors delivers or has delivered the initiator's identity.
   Callers wishing to perform context establishment only if anonymity
   support is provided should transfer a returned token from
   GSS_Init_sec_context() to the peer only if it is accompanied by a
   TRUE anon_state indicator.  When prot_ready_state is returned TRUE in
   conjunction with GSS_S_CONTINUE_NEEDED major_status, this indicates
   that per-message protection operations may be applied on the context:
   see Section 1.2.7 for further discussion of this facility.

   Failure to provide the precise set of features requested by the
   caller does not cause context establishment to fail; it is the
   caller's prerogative to delete the context if the feature set
   provided is unsuitable for the caller's use.

   The returned mech_type value indicates the specific mechanism
   employed on the context, is valid only along with major_status
   GSS_S_COMPLETE, and will never indicate the value for "default".
   Note that, for the case of certain mechanisms which themselves
   perform negotiation, the returned mech_type result may indicate
   selection of a mechanism identified by an OID different than that
   passed in the input mech_type argument.

   The conf_avail return value indicates whether the context supports
   per-message confidentiality services, and so informs the caller
   whether or not a request for encryption through the conf_req_flag

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   input to GSS_Wrap()  can be honored. In similar fashion, the
   integ_avail return value indicates whether per-message integrity
   services are available (through either GSS_GetMIC() or GSS_Wrap()) on
   the established context. These state indicators' values are undefined
   unless either the routine's major_status indicates GSS_S_COMPLETE, or
   TRUE prot_ready_state is returned along with GSS_S_CONTINUE_NEEDED
   major_status.

   The lifetime_req input specifies a desired upper bound for the
   lifetime of the context to be established, with a value of 0 used to
   request a default lifetime. The lifetime_rec return value indicates
   the length of time for which the context will be valid, expressed as
   an offset from the present; depending on mechanism capabilities,
   credential lifetimes, and local policy, it may not correspond to the
   value requested in lifetime_req.  If no constraints on context
   lifetime are imposed, this may be indicated by returning a reserved
   value representing INDEFINITE lifetime_req. The value of lifetime_rec
   is undefined unless the routine's major_status indicates
   GSS_S_COMPLETE.

   If the mutual_state is TRUE, this fact will be reflected within the
   output_token. A call to GSS_Accept_sec_context()  at the target in
   conjunction with such a context will return a token, to be processed
   by a continuation call to GSS_Init_sec_context(),  in order to
   achieve mutual authentication.

2.2.2:  GSS_Accept_sec_context call

   Inputs:

   o  acceptor_cred_handle CREDENTIAL HANDLE, -- NULL specifies
      "use default"

   o  input_context_handle CONTEXT HANDLE, -- 0 specifies
      "not yet assigned"

   o  chan_bindings OCTET STRING,

   o  input_token OCTET STRING

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  src_name INTERNAL NAME, -- guaranteed to be MN

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   o  mech_type OBJECT IDENTIFIER,

   o  output_context_handle CONTEXT HANDLE,

   o  deleg_state BOOLEAN,

   o  mutual_state BOOLEAN,

   o  replay_det_state BOOLEAN,

   o  sequence_state BOOLEAN,

   o  anon_state BOOLEAN,

   o  trans_state BOOLEAN,

   o  prot_ready_state BOOLEAN, -- see Section 1.2.7 for discussion

   o  conf_avail BOOLEAN,

   o  integ_avail BOOLEAN,

   o  lifetime_rec INTEGER, - in seconds, or reserved value for
      INDEFINITE

   o  delegated_cred_handle CREDENTIAL HANDLE,

   o  output_token OCTET STRING -NULL or token to pass to context
      initiator

   This call may block pending network interactions for those mech_types
   in which a directory service or other network entity must be
   consulted on behalf of a context acceptor in order to validate a
   received input_token.

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that context-level data structures
      were successfully initialized, and that per-message processing
      can now be performed in conjunction with this context.

   o  GSS_S_CONTINUE_NEEDED indicates that control information in the
      returned output_token must be sent to the initiator, and that
      a response must be received and passed as the input_token
      argument to a continuation call to GSS_Accept_sec_context(),
      before per-message processing can be performed in conjunction
      with this context.

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   o  GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed
      on the input_token failed, preventing further processing from
      being performed based on that token.

   o  GSS_S_DEFECTIVE_CREDENTIAL indicates that consistency checks
      performed on the credential structure referenced by
      acceptor_cred_handle failed, preventing further processing from
      being performed using that credential structure.

   o  GSS_S_BAD_SIG indicates that the received input_token contains
      an incorrect integrity check, so context setup cannot be
      accomplished.

   o  GSS_S_DUPLICATE_TOKEN indicates that the integrity check on the
      received input_token was correct, but that the input_token
      was recognized as a duplicate of an input_token already
      processed. No new context is established.

   o  GSS_S_OLD_TOKEN indicates that the integrity check on the received
      input_token was correct, but that the input_token is too old
      to be checked for duplication against previously-processed
      input_tokens. No new context is established.

   o  GSS_S_NO_CRED indicates that no context was established, either
      because the input cred_handle was invalid, because the
      referenced credentials are valid for context initiator use
      only, or because the caller lacks authorization to access the
      referenced credentials.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the credentials provided
      through the input acceptor_cred_handle argument are no
      longer valid, so context establishment cannot be completed.

   o  GSS_S_BAD_BINDINGS indicates that a mismatch between the
      caller-provided chan_bindings and those extracted from the
      input_token was detected, signifying a security-relevant
      event and preventing context establishment.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided; this major status will
      be returned only for successor calls following GSS_S_CONTINUE_
      NEEDED status returns.

   o  GSS_S_BAD_MECH indicates receipt of a context establishment token
      specifying a mechanism unsupported by the local system or with
      the caller's active credentials.

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   o  GSS_S_FAILURE indicates that context setup could not be
      accomplished for reasons unspecified at the GSS-API level, and
      that no interface-defined recovery action is available.

   The GSS_Accept_sec_context()  routine is used by a context target.
   Using information in the credentials structure referenced by the
   input acceptor_cred_handle, it verifies the incoming input_token and
   (following the successful completion of a context establishment
   sequence) returns the authenticated src_name and the mech_type used.
   The returned src_name is guaranteed to be an MN, processed by the
   mechanism under which the context was established. The
   acceptor_cred_handle must correspond to the same valid credentials
   structure on the initial call to GSS_Accept_sec_context() and on any
   successor calls resulting from GSS_S_CONTINUE_NEEDED status returns;
   different protocol sequences modeled by the GSS_S_CONTINUE_NEEDED
   mechanism will require access to credentials at different points in
   the context establishment sequence.

   The input_context_handle argument is 0, specifying "not yet
   assigned", on the first GSS_Accept_sec_context()  call relating to a
   given context.  If successful (i.e., if accompanied by major_status
   GSS_S_COMPLETE or GSS_S_CONTINUE_NEEDED), and only if successful, the
   initial GSS_Accept_sec_context() call returns a non-zero
   output_context_handle for use in future references to this context.
   Once a non-zero output_context_handle has been returned, GSS-API
   callers should call GSS_Delete_sec_context() to release context-
   related resources if errors occur in later phases of context
   establishment, or when an established context is no longer required.

   The chan_bindings argument is used by the caller to provide
   information binding the security context to security-related
   characteristics (e.g., addresses, cryptographic keys) of the
   underlying communications channel. See Section 1.1.6 of this document
   for more discussion of this argument's usage.

   The returned state results (deleg_state, mutual_state,
   replay_det_state, sequence_state, anon_state, trans_state, and
   prot_ready_state) reflect the same information as described for
   GSS_Init_sec_context(), and their values are significant under the
   same return state conditions.

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   The conf_avail return value indicates whether the context supports
   per-message confidentiality services, and so informs the caller
   whether or not a request for encryption through the conf_req_flag
   input to GSS_Wrap()  can be honored. In similar fashion, the
   integ_avail return value indicates whether per-message integrity
   services are available (through either GSS_GetMIC()  or GSS_Wrap())
   on the established context.  These values are significant under the
   same return state conditions as described under
   GSS_Init_sec_context().

   The lifetime_rec return value is significant only in conjunction with
   GSS_S_COMPLETE major_status, and indicates the length of time for
   which the context will be valid, expressed as an offset from the
   present.

   The mech_type return value indicates the specific mechanism employed
   on the context, is valid only along with major_status GSS_S_COMPLETE,
   and will never indicate the value for "default".

   The delegated_cred_handle result is significant only when deleg_state
   is TRUE, and provides a means for the target to reference the
   delegated credentials. The output_token result, when non-NULL,
   provides a context-level token to be returned to the context
   initiator to continue a multi-step context establishment sequence. As
   noted with GSS_Init_sec_context(),  any returned token should be
   transferred to the context's peer (in this case, the context
   initiator), independent of the value of the accompanying returned
   major_status.

   Note: A target must be able to distinguish a context-level
   input_token, which is passed to GSS_Accept_sec_context(),  from the
   per-message data elements passed to GSS_VerifyMIC()  or GSS_Unwrap().
   These data elements may arrive in a single application message, and
   GSS_Accept_sec_context()  must be performed before per-message
   processing can be performed successfully.

2.2.3: GSS_Delete_sec_context call

   Input:

   o  context_handle CONTEXT HANDLE

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

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   o  output_context_token OCTET STRING

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the context was recognized, and that
      relevant context-specific information was flushed.  If the caller
      provides a non-null buffer to receive an output_context_token, and
      the mechanism returns a non-NULL token into that buffer, the
      returned output_context_token is ready for transfer to the
      context's peer.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided, so no deletion was
      performed.

   o  GSS_S_FAILURE indicates that the context is recognized, but
      that the GSS_Delete_sec_context()  operation could not be
      performed for reasons unspecified at the GSS-API level.

   This call may block pending network interactions for mech_types in
   which active notification must be made to a central server when a
   security context is to be deleted.

   This call can be made by either peer in a security context, to flush
   context-specific information.  If a non-null output_context_token
   parameter is provided by the caller, an output_context_token may be
   returned to the caller.  If an output_context_token is provided to
   the caller, it can be passed to the context's peer to inform the
   peer's GSS-API implementation that the peer's corresponding context
   information can also be flushed. (Once a context is established, the
   peers involved are expected to retain cached credential and context-
   related information until the information's expiration time is
   reached or until a GSS_Delete_sec_context() call is made.)

   The facility for context_token usage to signal context deletion is
   retained for compatibility with GSS-API Version 1.  For current
   usage, it is recommended that both peers to a context invoke
   GSS_Delete_sec_context() independently, passing a null
   output_context_token buffer to indicate that no context_token is
   required.  Implementations of GSS_Delete_sec_context() should delete
   relevant locally-stored context information.

   Attempts to perform per-message processing on a deleted context will
   result in error returns.

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2.2.4:  GSS_Process_context_token call

   Inputs:

   o  context_handle CONTEXT HANDLE,

   o  input_context_token OCTET STRING

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the input_context_token was
      successfully processed in conjunction with the context
      referenced by context_handle.

   o  GSS_S_DEFECTIVE_TOKEN indicates that consistency checks
      performed on the received context_token failed, preventing
      further processing from being performed with that token.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided.

   o  GSS_S_FAILURE indicates that the context is recognized, but
      that the GSS_Process_context_token()  operation could not be
      performed for reasons unspecified at the GSS-API level.

   This call is used to process context_tokens received from a peer once
   a context has been established, with corresponding impact on
   context-level state information. One use for this facility is
   processing of the context_tokens generated by
   GSS_Delete_sec_context();  GSS_Process_context_token() will not block
   pending network interactions for that purpose. Another use is to
   process tokens indicating remote-peer context establishment failures
   after the point where the local GSS-API implementation has already
   indicated GSS_S_COMPLETE status.

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2.2.5:  GSS_Context_time call

   Input:

   o  context_handle CONTEXT HANDLE,

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  lifetime_rec INTEGER - in seconds, or reserved value for
      INDEFINITE

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the referenced context is valid,
      and will remain valid for the amount of time indicated in
      lifetime_rec.

   o  GSS_S_CONTEXT_EXPIRED indicates that data items related to the
      referenced context have expired.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the context is
      recognized, but that its associated credentials have expired.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided.

   o  GSS_S_FAILURE indicates that the requested operation failed for
       reasons unspecified at the GSS-API level.

   This call is used to determine the amount of time for which a
   currently established context will remain valid.

2.2.6:   GSS_Inquire_context call

   Input:

   o  context_handle CONTEXT HANDLE,

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

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   o  src_name INTERNAL NAME,  -- name of context initiator,
                               -- guaranteed to be MN

   o  targ_name INTERNAL NAME,  -- name of context target,
                                -- guaranteed to be MN


   o  lifetime_rec INTEGER -- in seconds, or reserved value for
      INDEFINITE,

   o  mech_type OBJECT IDENTIFIER, -- the mechanism supporting this
      security context

   o  deleg_state BOOLEAN,

   o  mutual_state BOOLEAN,

   o  replay_det_state BOOLEAN,

   o  sequence_state BOOLEAN,

   o  anon_state BOOLEAN,

   o  trans_state BOOLEAN,

   o  prot_ready_state BOOLEAN,

   o  conf_avail BOOLEAN,

   o  integ_avail BOOLEAN,

   o  locally_initiated BOOLEAN, -- TRUE if initiator, FALSE if acceptor

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the referenced context is valid
      and that src_name, targ_name, lifetime_rec, mech_type, deleg_state,
      mutual_state, replay_det_state, sequence_state, anon_state,
      trans_state, prot_ready_state, conf_avail, integ_avail, and
      locally_initiated return values describe the corresponding
      characteristics of the context.

   o  GSS_S_CONTEXT_EXPIRED indicates that the provided input
      context_handle is recognized, but that the referenced context
      has expired.  Return values other than major_status and
      minor_status are undefined.

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   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided. Return values other than
      major_status and minor_status are undefined.

   o  GSS_S_FAILURE indicates that the requested operation failed for
     reasons unspecified at the GSS-API level. Return values other than
         major_status and minor_status are undefined.

   This call is used to extract information describing characteristics
   of a security context.

2.2.7:   GSS_Wrap_size_limit call

   Inputs:

   o  context_handle CONTEXT HANDLE,

   o  qop INTEGER,

   o  output_size INTEGER

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  max_input_size INTEGER

   Return major_status codes:

   o  GSS_S_COMPLETE indicates a successful token size determination:
   an input message with a length in octets equal to the
   returned max_input_size value will, when passed to GSS_Wrap()
   for processing on the context identified by the context_handle
   parameter and with the quality of protection specifier provided
   in the qop parameter, yield an output token no larger than the
   value of the provided output_size parameter.

   o  GSS_S_CONTEXT_EXPIRED indicates that the provided input
   context_handle is recognized, but that the referenced context
   has expired.  Return values other than major_status and
   minor_status are undefined.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
   for the input context_handle provided. Return values other than
   major_status and minor_status are undefined.

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   o  GSS_S_BAD_QOP indicates that the provided QOP value is not
   recognized or supported for the context.

   o  GSS_S_FAILURE indicates that the requested operation failed for
   reasons unspecified at the GSS-API level. Return values other than
   major_status and minor_status are undefined.

   This call is used to determine the largest input datum which may be
   passed to GSS_Wrap() without yielding an output token larger than a
   caller-specified value.

2.2.8:   GSS_Export_sec_context call

   Inputs:

   o  context_handle CONTEXT HANDLE

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  interprocess_token OCTET STRING

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the referenced context has been
   successfully exported to a representation in the interprocess_token,
   and is no longer available for use by the caller.

   o  GSS_S_UNAVAILABLE indicates that the context export facility
   is not available for use on the referenced context.  (This status
   should occur only for contexts for which the trans_state value is
   FALSE.) Return values other than major_status and minor_status are
   undefined.

   o GSS_S_CONTEXT_EXPIRED indicates that the provided input
   context_handle is recognized, but that the referenced context has
   expired.  Return values other than major_status and minor_status are
   undefined.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
   for the input context_handle provided. Return values other than
   major_status and minor_status are undefined.

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   o  GSS_S_FAILURE indicates that the requested operation failed for
   reasons unspecified at the GSS-API level. Return values other than
   major_status and minor_status are undefined.

   This call generates an interprocess token for transfer to another
   process within an end system, in order to transfer control of a
   security context to that process.  The recipient of the interprocess
   token will call GSS_Import_sec_context() to accept the transfer.  The
   GSS_Export_sec_context() operation is defined for use only with
   security contexts which are fully and successfully established (i.e.,
   those for which GSS_Init_sec_context() and GSS_Accept_sec_context()
   have returned GSS_S_COMPLETE major_status).

   To ensure portability, a caller of GSS_Export_sec_context() must not
   assume that a context may continue to be used once it has been
   exported; following export, the context referenced by the
   context_handle cannot be assumed to remain valid.  Further, portable
   callers must not assume that a given interprocess token can be
   imported by GSS_Import_sec_context() more than once, thereby creating
   multiple instantiations of a single context.  GSS-API implementations
   may detect and reject attempted multiple imports, but are not
   required to do so.

   The internal representation contained within the interprocess token
   is an implementation-defined local matter.  Interprocess tokens
   cannot be assumed to be transferable across different GSS-API
   implementations.

   It is recommended that GSS-API implementations adopt policies suited
   to their operational environments in order to define the set of
   processes eligible to import a context, but specific constraints in
   this area are local matters.  Candidate examples include transfers
   between processes operating on behalf of the same user identity, or
   processes comprising a common job.  However, it may be impossible to
   enforce such policies in some implementations.

   In support of the above goals, implementations may protect the
   transferred context data by using cryptography to protect data within
   the interprocess token, or by using interprocess tokens as a means to
   reference local interprocess communication facilities (protected by
   other means) rather than storing the context data directly within the
   tokens.

   Transfer of an open context may, for certain mechanisms and
   implementations, reveal data about the credential which was used to
   establish the context.  Callers should, therefore, be cautious about
   the trustworthiness of processes to which they transfer contexts.
   Although the GSS-API implementation may provide its own set of

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   protections over the exported context, the caller is responsible for
   protecting the interprocess token from disclosure, and for taking
   care that the context is transferred to an appropriate destination
   process.

2.2.9:   GSS_Import_sec_context call

   Inputs:

   o  interprocess_token OCTET STRING

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  context_handle CONTEXT HANDLE

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the context represented by the
   input interprocess_token has been successfully transferred to
   the caller, and is available for future use via the output
   context_handle.

   o  GSS_S_CONTEXT_EXPIRED indicates that the context represented by
   the input interprocess_token has expired. Return values other
   than major_status and minor_status are undefined.

   o  GSS_S_NO_CONTEXT indicates that the context represented by the
   input interprocess_token was invalid. Return values other than
   major_status and minor_status are undefined.

   o  GSS_S_DEFECTIVE_TOKEN indicates that the input interprocess_token
   was defective.  Return values other than major_status and
   minor_status are undefined.

   o  GSS_S_UNAVAILABLE indicates that the context import facility
   is not available for use on the referenced context.  Return values
   other than major_status and minor_status are undefined.

   o  GSS_S_UNAUTHORIZED indicates that the context represented by
   the input interprocess_token is unauthorized for transfer to the
   caller. Return values other than major_status and minor_status
   are undefined.

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   o  GSS_S_FAILURE indicates that the requested operation failed for
   reasons unspecified at the GSS-API level. Return values other than
   major_status and minor_status are undefined.

   This call processes an interprocess token generated by
   GSS_Export_sec_context(), making the transferred context available
   for use by the caller.  After a successful GSS_Import_sec_context()
   operation, the imported context is available for use by the importing
   process.

   For further discussion of the security and authorization issues
   regarding this call, please see the discussion in Section 2.2.8.

2.3:  Per-message calls

   This group of calls is used to perform per-message protection
   processing on an established security context. None of these calls
   block pending network interactions. These calls may be invoked by a
   context's initiator or by the context's target.  The four members of
   this group should be considered as two pairs; the output from
   GSS_GetMIC()  is properly input to GSS_VerifyMIC(),  and the output
   from GSS_Wrap() is properly input to GSS_Unwrap().

   GSS_GetMIC() and GSS_VerifyMIC() support data origin authentication
   and data integrity services. When GSS_GetMIC()  is invoked on an
   input message, it yields a per-message token containing data items
   which allow underlying mechanisms to provide the specified security
   services. The original message, along with the generated per-message
   token, is passed to the remote peer; these two data elements are
   processed by GSS_VerifyMIC(),  which validates the message in
   conjunction with the separate token.

   GSS_Wrap() and GSS_Unwrap() support caller-requested confidentiality
   in addition to the data origin authentication and data integrity
   services offered by GSS_GetMIC()  and GSS_VerifyMIC(). GSS_Wrap()
   outputs a single data element, encapsulating optionally enciphered
   user data as well as associated token data items.  The data element
   output from GSS_Wrap()  is passed to the remote peer and processed by
   GSS_Unwrap()  at that system. GSS_Unwrap() combines decipherment (as
   required) with validation of data items related to authentication and
   integrity.

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2.3.1:  GSS_GetMIC call

   Note: This call is functionally equivalent to the GSS_Sign call as
   defined in previous versions of this specification. In the interests
   of backward compatibility, it is recommended that implementations
   support this function under both names for the present; future
   references to this function as GSS_Sign are deprecated.

   Inputs:

   o  context_handle CONTEXT HANDLE,

   o  qop_req INTEGER,-0 specifies default QOP

   o  message OCTET STRING

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  per_msg_token OCTET STRING

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that an integrity check, suitable for an
      established security context, was successfully applied and
      that the message and corresponding per_msg_token are ready
      for transmission.

   o  GSS_S_CONTEXT_EXPIRED indicates that context-related data
      items have expired, so that the requested operation cannot be
      performed.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the context is recognized,
      but that its associated credentials have expired, so
      that the requested operation cannot be performed.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided.

   o  GSS_S_BAD_QOP indicates that the provided QOP value is not
      recognized or supported for the context.

   o  GSS_S_FAILURE indicates that the context is recognized, but
      that the requested operation could not be performed for
      reasons unspecified at the GSS-API level.

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   Using the security context referenced by context_handle, apply an
   integrity check to the input message (along with timestamps and/or
   other data included in support of mech_type-specific mechanisms) and
   return the result in per_msg_token. The qop_req parameter,
   interpretation of which is discussed in Section 1.2.4, allows
   quality-of-protection control. The caller passes the message and the
   per_msg_token to the target.

   The GSS_GetMIC()  function completes before the message and
   per_msg_token is sent to the peer; successful application of
   GSS_GetMIC()  does not guarantee that a corresponding GSS_VerifyMIC()
   has been (or can necessarily be) performed successfully when the
   message arrives at the destination.

   Mechanisms which do not support per-message protection services
   should return GSS_S_FAILURE if this routine is called.

2.3.2:  GSS_VerifyMIC call

   Note: This call is functionally equivalent to the GSS_Verify call as
   defined in previous versions of this specification. In the interests
   of backward compatibility, it is recommended that implementations
   support this function under both names for the present; future
   references to this function as GSS_Verify are deprecated.

   Inputs:

   o  context_handle CONTEXT HANDLE,

   o  message OCTET STRING,

   o  per_msg_token OCTET STRING

   Outputs:

   o  qop_state INTEGER,

   o  major_status INTEGER,

   o  minor_status INTEGER,

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the message was successfully
      verified.

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   o  GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed
      on the received per_msg_token failed, preventing
      further processing from being performed with that token.

   o  GSS_S_BAD_SIG indicates that the received per_msg_token contains
      an incorrect integrity check for the message.

   o  GSS_S_DUPLICATE_TOKEN, GSS_S_OLD_TOKEN, GSS_S_UNSEQ_TOKEN,
      and GSS_S_GAP_TOKEN values appear in conjunction with the
      optional per-message replay detection features described
      in Section 1.2.3; their semantics are described in that section.

   o  GSS_S_CONTEXT_EXPIRED indicates that context-related data
      items have expired, so that the requested operation cannot be
      performed.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the context is
   recognized,
      but that its associated credentials have expired, so
      that the requested operation cannot be performed.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided.

   o  GSS_S_FAILURE indicates that the context is recognized, but
      that the GSS_VerifyMIC() operation could not be performed for
      reasons unspecified at the GSS-API level.

   Using the security context referenced by context_handle, verify that
   the input per_msg_token contains an appropriate integrity check for
   the input message, and apply any active replay detection or
   sequencing features. Return an indication of the quality-of-
   protection applied to the processed message in the qop_state result.
   Since the GSS_VerifyMIC() routine never provides a confidentiality
   service, its implementations should not return non-zero values in the
   confidentiality fields of the output qop_state.

   Mechanisms which do not support per-message protection services
   should return GSS_S_FAILURE if this routine is called.

2.3.3: GSS_Wrap call

   Note: This call is functionally equivalent to the GSS_Seal call as
   defined in previous versions of this specification. In the interests
   of backward compatibility, it is recommended that implementations
   support this function under both names for the present; future
   references to this function as GSS_Seal are deprecated.

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   Inputs:

   o  context_handle CONTEXT HANDLE,

   o  conf_req_flag BOOLEAN,

   o  qop_req INTEGER,-0 specifies default QOP

   o  input_message OCTET STRING

   Outputs:

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  conf_state BOOLEAN,

   o  output_message OCTET STRING

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the input_message was successfully
      processed and that the output_message is ready for
      transmission.

   o  GSS_S_CONTEXT_EXPIRED indicates that context-related data
      items have expired, so that the requested operation cannot be
      performed.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the context is
   recognized,
      but that its associated credentials have expired, so
      that the requested operation cannot be performed.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided.

   o  GSS_S_BAD_QOP indicates that the provided QOP value is not
      recognized or supported for the context.

   o  GSS_S_FAILURE indicates that the context is recognized, but
      that the GSS_Wrap()  operation could not be performed for
      reasons unspecified at the GSS-API level.

   Performs the data origin authentication and data integrity functions
   of GSS_GetMIC().  If the input conf_req_flag is TRUE, requests that
   confidentiality be applied to the input_message.  Confidentiality may

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   not be supported in all mech_types or by all implementations; the
   returned conf_state flag indicates whether confidentiality was
   provided for the input_message. The qop_req parameter, interpretation
   of which is discussed in Section 1.2.4, allows quality-of-protection
   control.

   In all cases, the GSS_Wrap()  call yields a single output_message
   data element containing (optionally enciphered) user data as well as
   control information.

   Mechanisms which do not support per-message protection services
   should return GSS_S_FAILURE if this routine is called.

2.3.4: GSS_Unwrap call

   Note: This call is functionally equivalent to the GSS_Unseal call as
   defined in previous versions of this specification. In the interests
   of backward compatibility, it is recommended that implementations
   support this function under both names for the present; future
   references to this function as GSS_Unseal are deprecated.

   Inputs:

   o  context_handle CONTEXT HANDLE,

   o  input_message OCTET STRING

   Outputs:

   o  conf_state BOOLEAN,

   o  qop_state INTEGER,

   o  major_status INTEGER,

   o  minor_status INTEGER,

   o  output_message OCTET STRING

   Return major_status codes:

   o  GSS_S_COMPLETE indicates that the input_message was
      successfully processed and that the resulting output_message is
      available.

   o  GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed
      on the per_msg_token extracted from the input_message
      failed, preventing further processing from being performed.

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   o  GSS_S_BAD_SIG indicates that an incorrect integrity check was
   detected
      for the message.

   o  GSS_S_DUPLICATE_TOKEN, GSS_S_OLD_TOKEN, GSS_S_UNSEQ_TOKEN,
      and GSS_S_GAP_TOKEN values appear in conjunction with the
      optional per-message replay detection features described
      in Section 1.2.3; their semantics are described in that section.

   o  GSS_S_CONTEXT_EXPIRED indicates that context-related data
      items have expired, so that the requested operation cannot be
      performed.

   o  GSS_S_CREDENTIALS_EXPIRED indicates that the context is
   recognized,
      but that its associated credentials have expired, so
      that the requested operation cannot be performed.

   o  GSS_S_NO_CONTEXT indicates that no valid context was recognized
      for the input context_handle provided.

   o  GSS_S_FAILURE indicates that the context is recognized, but
      that the GSS_Unwrap()  operation could not be performed for
      reasons unspecified at the GSS-API level.

   Processes a data element generated (and optionally enciphered) by
   GSS_Wrap(),  provided as input_message. The returned conf_state value
   indicates whether confidentiality was applied to the input_message.
   If conf_state is TRUE, GSS_Unwrap()  deciphers the input_message.
   Returns an indication of the quality-of-protection applied to the
   processed message in the qop_state result. GSS_Wrap()  performs the
   data integrity and data origin authentication checking functions of
   GSS_VerifyMIC()  on the plaintext data. Plaintext data is returned in
   output_message.

   Mechanisms which do not support per-message protection services
   should return GSS_S_FAILURE if this routine is called.



(page 59 continued on part 3)

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