<pre>Network Working Group                                           C. Adams
Request for Comments: 2479                          Entrust Technologies
Category: Informational                                    December 1998


       <span class="h1">Independent Data Unit Protection Generic Security Service</span>
              <span class="h1">Application Program Interface (IDUP-GSS-API)</span>

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

ABSTRACT

   The IDUP-GSS-API extends the GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>] for applications
   requiring protection of a generic data unit (such as a file or
   message) in a way which is independent of the protection of any other
   data unit and independent of any concurrent contact with designated
   "receivers" of the data unit.  Thus, it is suitable for applications
   such as secure electronic mail where data needs to be protected
   without any on-line connection with the intended recipient(s) of that
   data.  The protection offered by IDUP includes services such as data
   origin authentication with data integrity, data confidentiality with
   data integrity, and support for non-repudiation services.  Subsequent
   to being protected, the data unit can be transferred to the
   recipient(s) - or to an archive - perhaps to be processed
   ("unprotected") only days or years later.

   Throughout the remainder of this document, the "unit" of data
   described in the above paragraph will be referred to as an IDU
   (Independent Data Unit).  The IDU can be of any size (the application
   may, if it wishes, split the IDU into pieces and have the protection
   computed a piece at a time, but the resulting protection token
   applies to the entire IDU).  However, the primary characteristic of
   an IDU is that it represents a stand-alone unit of data whose
   protection is entirely independent of any other unit of data.  If an
   application protects several IDUs and sends them all to a single
   receiver, the IDUs may be unprotected by that receiver in any order
   over any time span; no logical connection of any kind is implied by
   the protection process itself.





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   As with <a href="./rfc2078">RFC-2078</a>, this IDUP-GSS-API definition provides security
   services to callers in a generic fashion, supportable with a range of
   underlying mechanisms and technologies and hence allowing source-
   level portability of applications to different environments. This
   specification defines IDUP-GSS-API services and primitives at a level
   independent of underlying mechanism and programming language
   environment, and is to be complemented by other, related
   specifications:

      - documents defining specific parameter bindings for particular
        language environments;
      - documents defining token formats, protocols, and procedures to
        be implemented in order to realize IDUP-GSS-API services atop
        particular security mechanisms.

TABLE OF CONTENTS

   <a href="#section-1">1</a>.  IDUP-GSS-API Characteristics and Concepts ..................    <a href="#page-3">3</a>
   <a href="#section-1.1">1.1</a>.  IDUP-GSS-API Constructs ..................................    <a href="#page-5">5</a>
   <a href="#section-1.1.1">1.1.1</a>.  Credentials ............................................    <a href="#page-5">5</a>
   <a href="#section-1.1.2">1.1.2</a>.  Tokens .................................................    <a href="#page-5">5</a>
   <a href="#section-1.1.3">1.1.3</a>.  Security Environment ...................................    <a href="#page-6">6</a>
   <a href="#section-1.1.4">1.1.4</a>.  Mechanism Types ........................................    <a href="#page-6">6</a>
   <a href="#section-1.1.5">1.1.5</a>.  Naming .................................................    <a href="#page-6">6</a>
   <a href="#section-1.1.6">1.1.6</a>.  Channel Bindings .......................................    <a href="#page-6">6</a>
   <a href="#section-1.2">1.2</a>.  IDUP-GSS-API Features and Issues .........................    <a href="#page-6">6</a>
   <a href="#section-1.2.1">1.2.1</a>.  Status Reporting .......................................    <a href="#page-6">6</a>
   <a href="#section-1.2.2">1.2.2</a>.  Per-IDU Security Service Availability ..................    <a href="#page-9">9</a>
   <a href="#section-1.2.3">1.2.3</a>.  Per-IDU Replay Detection and Sequencing ................    <a href="#page-9">9</a>
   <a href="#section-1.2.4">1.2.4</a>.  Quality of Protection ..................................    <a href="#page-9">9</a>
   <a href="#section-1.2.5">1.2.5</a>.  The Provision of Time ..................................   <a href="#page-12">12</a>
   <a href="#section-2">2</a>.  Interface Descriptions .....................................   <a href="#page-13">13</a>
   <a href="#section-2.1">2.1</a>.  Credential management calls ..............................   <a href="#page-14">14</a>
   <a href="#section-2.1.1">2.1.1</a>.  Relationship to GSS-API ................................   <a href="#page-14">14</a>
   <a href="#section-2.2">2.2</a>.  Environment-level calls ..................................   <a href="#page-15">15</a>
   <a href="#section-2.2.1">2.2.1</a>.  Relationship to GSS-API ................................   <a href="#page-15">15</a>
   <a href="#section-2.2.2">2.2.2</a>.  IDUP_Establish_Env call ................................   <a href="#page-15">15</a>
   <a href="#section-2.2.3">2.2.3</a>.  IDUP_Abolish_Env call ..................................   <a href="#page-19">19</a>
   <a href="#section-2.2.4">2.2.4</a>.  IDUP_Inquire_Env call ..................................   <a href="#page-19">19</a>
   <a href="#section-2.3">2.3</a>.  Per-IDU protection/unprotection calls ....................   <a href="#page-20">20</a>
   <a href="#section-2.3.1">2.3.1</a>.  Relationship to GSS-API ................................   <a href="#page-20">20</a>
   <a href="#section-2.3.2">2.3.2</a>.  The "SE" Calls .........................................   <a href="#page-21">21</a>
   <a href="#section-2.3.3">2.3.3</a>.  The "EV" Calls .........................................   <a href="#page-27">27</a>
   <a href="#section-2.3.4">2.3.4</a>.  The "GP" Calls .........................................   <a href="#page-36">36</a>
   <a href="#section-2.4">2.4</a>.  Special-Purpose calls ....................................   <a href="#page-47">47</a>
   <a href="#section-2.4.1">2.4.1</a>.  Relationship to GSS-API ................................   <a href="#page-47">47</a>
   <a href="#section-2.4.2">2.4.2</a>.  IDUP_Form_Complete_PIDU ................................   <a href="#page-48">48</a>
   <a href="#section-2.5">2.5</a>.  Support calls ............................................   <a href="#page-49">49</a>



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   <a href="#section-2.5.1">2.5.1</a>.  Relationship to GSS-API ................................   <a href="#page-49">49</a>
   <a href="#section-2.5.2">2.5.2</a>.  IDUP_Acquire_Cred_With_Auth ............................   <a href="#page-49">49</a>
   <a href="#section-2.5.3">2.5.3</a>.  IDUP_Get_Token_Details .................................   <a href="#page-50">50</a>
   <a href="#section-2.5.4">2.5.4</a>.  IDUP_Get_Policy_Info ...................................   <a href="#page-53">53</a>
   <a href="#section-2.5.5">2.5.5</a>.  IDUP_Cancel_Multibuffer_Op .............................   <a href="#page-55">55</a>
   <a href="#section-3">3</a>.  Related Activities .........................................   <a href="#page-55">55</a>
   <a href="#section-4">4</a>.  Acknowledgments ............................................   <a href="#page-56">56</a>
   <a href="#section-5">5</a>.  Security Considerations ....................................   <a href="#page-56">56</a>
   <a href="#section-6">6</a>.  References       ...........................................   <a href="#page-56">56</a>
   <a href="#section-7">7</a>.  Author's Address ...........................................   <a href="#page-56">56</a>
   Appendix  A Mechanism-Independent Token Format .................   <a href="#page-57">57</a>
   Appendix  B Examples of IDUP Use ...............................   <a href="#page-58">58</a>
   Full Copyright Statement .......................................   <a href="#page-70">70</a>

<span class="h2"><a class="selflink" id="section-1" href="#section-1">1</a>. IDUP-GSS-API Characteristics and Concepts</span>

   The paradigm within which IDUP-GSS-API operates is as follows.  An
   IDUP-GSS-API caller is any application that works with IDUs, calling
   on IDUP-GSS-API in order to protect its IDUs with services such as
   data origin authentication with integrity (DOA), confidentiality with
   integrity (CONF), and/or support for non-repudiation (e.g., evidence
   generation, where "evidence" is information that either by itself, or
   when used in conjunction with other information, is used to establish
   proof about an event or action (note:  the evidence itself does not
   necessarily prove truth or existence of something, but contributes to
   establish proof) -- see [ISO/IEC] for fuller discussion regarding
   evidence and its role in various types of non-repudiation).  An
   IDUP-GSS-API caller passes an IDU to, and accepts a token from, its
   local IDUP-GSS-API implementation, transferring the resulting
   protected IDU (P-IDU) to a peer or to any storage medium.  When a P-
   IDU is to be "unprotected", it is passed to an IDUP-GSS-API
   implementation for processing.  The security services available
   through IDUP-GSS-API in this fashion are implementable over a range
   of underlying mechanisms based on secret-key and/or public-key
   cryptographic technologies.

   During the protection operation, the input IDU buffers may be
   modified (for example, the data may be encrypted or encoded in some
   way) or may remain unchanged.  In any case, the result is termed a
   "M-IDU" (Modified IDU) in order to distinguish it from the original
   IDU.  Depending on the desire of the calling application and the
   capabilities of the underlying IDUP mechanism, the output produced by
   the protection processing may or may not encapsulate the M-IDU. Thus,
   the P-IDU may be the contents of a single output parameter (if
   encapsulation is done) or may be the logical concatenation of an
   unencapsulated token parameter and a M-IDU parameter (if
   encapsulation is not done).  In the latter case, the protecting
   application may choose whatever method it wishes to concatenate or



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   combine the unencapsulated token and the M-IDU into a P-IDU, provided
   the unprotecting application knows how to de-couple the P-IDU back
   into its component parts prior to calling the IDUP unprotection set
   of functions.

   It is expected that any output buffer returned by IDUP (i.e., P-IDU
   or portion thereof) is ready for immediate transmission to the
   intended receiver(s) by the calling application, if this is desired.
   In other words, an application wishing to transmit data buffers as
   they appear from IDUP should not be unduly restricted from doing so
   by the underlying mechanism.

   The IDUP-GSS-API separates the operation of initializing a security
   environment (the IDUP_Establish_Env() call) from the operations of
   providing per-IDU protection, for IDUs subsequently protected in
   conjunction with that environment. Per-IDU protection and
   unprotection calls provide DOA, CONF, evidence, and other services,
   as requested by the calling application and as supported by the
   underlying mechanism.

   The following paragraphs provide an example illustrating the
   dataflows involved in the use of the IDUP-GSS-API by the sender and
   receiver of a P-IDU in a mechanism-independent fashion.  The example
   assumes that credential acquisition has already been completed by
   both sides.  Furthermore, the example does not cover all possible
   options available in the protection/unprotection calls.

      The sender first calls IDUP_Establish_Env() to establish a
      security environment.  Then, for the IDU to be protected the
      sender calls the appropriate protection calls (SE, EV, or GP) to
      perform the IDU protection.  The resulting P-IDU, which may
      (depending on whether or not encapsulation was chosen/available)
      be either the token itself or the logical concatenation of the
      token and the M-IDU, is now ready to be sent to the target.  The
      sender then calls IDUP_Abolish_Env() to flush all environment-
      specific information.

      The receiver first calls IDUP_Establish_Env() to establish a
      security environment in order to unprotect the P-IDU.  Then, for
      the received P-IDU the receiver calls the appropriate unprotection
      calls (SE, EV, or GP (known a priori, or possibly determined
      through the use of the IDUP_Get_token_details call)) to perform
      the P-IDU unprotection.  The receiver then calls
      IDUP_Abolish_Env() to flush all environment-specific information.

   It is important to note that absolutely no synchronization is implied
   or expected between the data buffer size used by the sender as input
   to the protection calls, the data buffer size used by the receiver as



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   input to the unprotection calls, and the block sizes required by the
   underlying protection algorithms (integrity and confidentiality). All
   these sizes are meant to be independent; furthermore, the data buffer
   sizes used for the protection and unprotection calls are purely a
   function of the local environment where the calls are made.

   The IDUP-GSS-API design assumes and addresses several basic goals,
   including the following.

      Mechanism independence:  The IDUP-GSS-API defines an interface to
      cryptographically implemented security services at a generic level
      which is independent of particular underlying mechanisms. For
      example, IDUP-GSS-API-provided services can be implemented by
      secret-key technologies or public-key approaches.

      Protocol environment independence: The IDUP-GSS-API is independent
      of the communications protocol suites which may be used to
      transfer P-IDUs, permitting use in a broad range of protocol
      environments.

      Protocol association independence: The IDUP-GSS-API's security
      environment construct has nothing whatever to do with
      communications protocol association constructs, so that IDUP-GSS-
      API services can be invoked by applications, wholly independent of
      protocol associations.

      Suitability for a range of implementation placements: IDUP-GSS-API
      clients are not constrained to reside within any Trusted Computing
      Base (TCB) perimeter defined on a system where the IDUP-GSS-API is
      implemented; security services are specified in a manner suitable
      for both intra-TCB and extra-TCB callers.

<span class="h3"><a class="selflink" id="section-1.1" href="#section-1.1">1.1</a>. IDUP-GSS-API Constructs</span>

   This section describes the basic elements comprising the IDUP-GSS-
   API.

<span class="h4"><a class="selflink" id="section-1.1.1" href="#section-1.1.1">1.1.1</a>.  Credentials</span>

   Credentials in IDUP-GSS-API are to be understood and used as
   described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].

<span class="h4"><a class="selflink" id="section-1.1.2" href="#section-1.1.2">1.1.2</a>. Tokens</span>

   Tokens in IDUP-GSS-API are to be understood and used as described in
   GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>] with the exception that there are no context-level
   tokens generated by IDUP-GSS-API.  The IDUP-GSS-API token may
   (depending on the underlying mechanism) encapsulate the M-IDU or may



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   be logically concatenated with the M-IDU prior to transfer to a
   target; furthermore, for some evidence services the token may be sent
   independently of any other data transfer.

<span class="h4"><a class="selflink" id="section-1.1.3" href="#section-1.1.3">1.1.3</a>.  Security Environment</span>

   The "security environment" in IDUP-GSS-API is entirely different from
   the concept of security contexts used in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].  Here, a
   security environment exists within a calling application (that is, it
   is purely local to the caller) for the purpose of protecting or
   unprotecting one or more IDUs using a particular caller credential or
   set of credentials.  In GSS-API, on the other hand, a security
   context exists between peers (the initiator and the target) for the
   purpose of protecting, in real time, the data that is exchanged
   between them.  Although they are different concepts, the env_handle
   in IDUP-GSS-API is similar to the context_handle in GSS-API in that
   it is a convenient way of tying together the entire process of
   protecting or unprotecting one or more IDUs using a particular
   underlying mechanism.  As with the GSS-API security contexts, a
   caller can initiate and maintain multiple environments using the same
   or different credentials.

<span class="h4"><a class="selflink" id="section-1.1.4" href="#section-1.1.4">1.1.4</a>.  Mechanism Types</span>

   Mechanism types in IDUP-GSS-API are to be understood and used as
   described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].

<span class="h4"><a class="selflink" id="section-1.1.5" href="#section-1.1.5">1.1.5</a>.  Naming</span>

   Naming in IDUP-GSS-API is to be understood and used as described in
   GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].

<span class="h4"><a class="selflink" id="section-1.1.6" href="#section-1.1.6">1.1.6</a>.  Channel Bindings</span>

   The concept of channel bindings discussed in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>] is
   not relevant to the IDUP-GSS-API.

<span class="h3"><a class="selflink" id="section-1.2" href="#section-1.2">1.2</a>.  IDUP-GSS-API Features and Issues</span>

   This section describes aspects of IDUP-GSS-API operations and of the
   security services which the IDUP-GSS-API provides.  It also provides
   commentary on design issues.

<span class="h4"><a class="selflink" id="section-1.2.1" href="#section-1.2.1">1.2.1</a>.  Status Reporting</span>

   Status reporting in IDUP-GSS-API is to be understood and used as
   described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>], with the addition of a number of
   IDUP-specific status codes.  Descriptions of the major_status codes



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   used in IDUP are provided in Table 1.  Codes that are informatory
   (i.e., that do not cause the requested operation to fail) are
   indicated with the symbol "(I)".

   As with GSS-API, minor_status codes, which provide more detailed
   status information than major_status codes, and which may include
   status codes specific to the underlying security mechanism, are not
   specified in this document.

    Table 1: IDUP-GSS-API Major Status Codes

      GSS_S_BAD_MECH indicates that a mech_type unsupported by the
      IDUP_GSS-API implementation was requested, causing the environment
      establishment operation to fail.

      GSS_S_BAD_QOP indicates that the provided qop_alg value is not
      recognized or supported for the environment.

      GSS_S_BAD_MIC indicates that the received P-IDU contains an
      incorrect integrity field (e.g., signature or MAC) for the data.

      GSS_S_COMPLETE indicates that the requested operation was
      successful.

      GSS_S_CREDENTIALS_EXPIRED indicates that the credentials
      associated with this operation have expired, so that the requested
      operation cannot be performed.

      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.

      GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed
      on the received P-IDU failed, preventing further processing from
      being performed.

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

      GSS_S_NO_CRED indicates that no environment was established,
      either because the input cred_handle was invalid or because the
      caller lacks authorization to access the referenced credentials.

      IDUP_S_BAD_DOA_KEY indicates that the key used to provide IDU data
      origin auth. / integ. has either expired or been revoked.




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      IDUP_S_BAD_ENC_IDU indicates that decryption of the received IDU
      cannot be completed because the encrypted IDU was
      invalid/defective (e.g., the final block was short or had
      incorrect padding).

      IDUP_S_BAD_KE_KEY indicates that the key used to establish a key
      for confidentiality purposes between originator and target has
      either expired or been revoked.

      IDUP_S_BAD_TARG_INFO indicates that the full set of supplied
      information regarding the target(s) is invalid or is insufficient
      for the protection of an IDU, so P-IDU cannot be created.

      IDUP_S_DEFECTIVE_VERIF indicates that consistency checks performed
      on Service_Verification_Info failed, preventing further processing
      from being performed with that parameter.

      IDUP_S_ENCAPSULATION_UNAVAIL (I) indicates that the underlying
      mechanism does not support encapsulation of the M-IDU into the
      token.

      IDUP_S_INAPPROPRIATE_CRED indicates that the credentials supplied
      do not contain the information necessary for P-IDU unprotection.

      IDUP_S_INCOMPLETE (I) indicates that the unprotection of the P-IDU
      is not yet complete (i.e., a determination cannot yet be made on
      the validity of the P-IDU).  The application should call
      IDUP_Form_Complete_PIDU and then should call this function again
      with the complete P-IDU.

      IDUP_S_INCONSISTENT_PARAMS indicates that the supplied parameters
      are inconsistent (e.g., only one or the other of two parameters
      may be supplied, but both have been input).

      IDUP_S_MORE_OUTBUFFER_NEEDED (I) indicates that the output buffer
      supplied is too small to hold the generated data.  The application
      should continue calling this routine (until GSS_S_COMPLETE is
      returned) in order to get all remaining output data.

      IDUP_S_MORE_PIDU_NEEDED (I) indicates that not enough of the P-IDU
      has been input yet for the completion of StartUnprotect.  The
      application should call this routine again with another buffer of
      P-IDU in partial(initial)_pidu_buffer.

      IDUP_S_NO_ENV indicates that no valid environment was recognized
      for the env_handle provided.





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      IDUP_S_NO_MATCH indicates that Service_Verification_Info (or
      evidence_check) and the P-IDU to be verified do not match.

      IDUP_S_REQ_TIME_SERVICE_UNAVAIL indicates that the time service
      requested (TTIME or UTIME) is not available in the environment.

      IDUP_S_SERVICE_UNAVAIL indicates that the underlying mechanism
      does not support the service requested.

      IDUP_S_SERV_VERIF_INFO_NEEDED (I) indicates that the
      Service_Verification_Info parameter bundle must be input in order
      for service verification to proceed.  The output parameter
      service_verification_info_id contains an identifier which may be
      used by the calling application to locate the necessary
      information.

      IDUP_S_UNKNOWN_OPER_ID indicates that the input prot_oper_id value
      is not recognized or supported in the underlying mechanism.

<span class="h4"><a class="selflink" id="section-1.2.2" href="#section-1.2.2">1.2.2</a>. Per-IDU Security Service Availability</span>

   Per-IDU security service availability in IDUP-GSS-API is to be
   understood and used as described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>], with the
   exception that combinations of services requested by the calling
   application and supported by the underlying mechanism may be applied
   simultaneously to any IDU (true for both the SE and the EV calls, but
   true in the fullest sense for the GP calls).

   GSS-API callers desiring per-message security services should check
   the relevant service OBJECT IDs at environment establishment time to
   ensure that what is available in the established environment is
   suitable for their security needs.

<span class="h4"><a class="selflink" id="section-1.2.3" href="#section-1.2.3">1.2.3</a>. Per-IDU Replay Detection and Sequencing</span>

   The concept of per-IDU replay detection and sequencing discussed in
   GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>] is not relevant to the IDUP-GSS-API.

<span class="h4"><a class="selflink" id="section-1.2.4" href="#section-1.2.4">1.2.4</a>.  Quality of Protection</span>

   The concept of QOP control in IDUP-GSS-API is to be understood
   essentially as described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].  However, the actual
   description and use of the QOP parameter is given as follows.

   The qop_algs parameter for IDUP is defined to be a 32-bit unsigned
   integer with the following bit-field assignments:





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


            31 (MSB)                               (LSB) 0
            ----------------------------------------------
            |        U(19)       | TS(5) | IA(4) | MA(4) |
            ----------------------------------------------

   where

      U is a 19-bit Unspecified field (available for future
      use/expansion) -- must be set to zero;

      TS is a 5-bit Type Specifier (a semantic qualifier whose value
      specifies the type of algorithm which may be used to protect the
      corresponding IDU -- see below for details);

      IA is a 4-bit field enumerating Implementation-specific
      Algorithms; and

      MA is a 4-bit field enumerating Mechanism-defined Algorithms.

   The interpretation of the qop_algs parameter is as follows.  The MA
   field is examined first.  If it is non-zero then the algorithm used
   to protect the IDU is the mechanism-specified algorithm corresponding
   to that integer value.

   If MA is zero then IA is examined.  If this field value is non-zero
   then the algorithm used to protect the IDU is the implementation-
   specified algorithm corresponding to that integer value.  Note that
   use of this field may hinder portability since a particular value may
   specify one algorithm in one implementation of the mechanism and may
   not be supported or may specify a completely different algorithm in
   another implementation of the mechanism.

   Finally, if both MA and IA are zero then TS is examined.  A value of
   zero for TS specifies the default algorithm for the established
   mechanism.  A non-zero value for TS corresponds to a particular
   algorithm qualifier and selects any algorithm from the mechanism
   specification which satisfies that qualifier (which actual algorithm
   is selected is an implementation choice; the calling application need
   not be aware of the choice made).

   The following TS values (i.e., algorithm qualifiers) are specified;
   other values may be added in the future.









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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   When qop_algs is used to select a confidentiality algorithm:

      00000  (0) = default confidentiality algorithm
      00001  (1) = IDUP_SYM_ALG_STRENGTH_STRONG
      00010  (2) = IDUP_SYM_ALG_STRENGTH_MEDIUM
      00011  (3) = IDUP_SYM_ALG_STRENGTH_WEAK
      11111 (31) = IDUP_NO_CONFIDENTIALITY

   When qop_algs is used to select a DOA/integrity algorithm:

      00000  (0) = default integrity algorithm
      00001  (1) = IDUP_INT_ALG_DIG_SIGNATURE
                   (integrity provided through a digital signature)
      00010  (2) = IDUP_INT_ALG_NON_DIG_SIGNATURE
                   (integrity without a dig. sig. (e.g., with a MAC))
      11111 (31) = IDUP_NO_INTEGRITY

   Clearly, qualifiers such as strong, medium, and weak are debatable
   and likely to change with time, but for the purposes of this version
   of the specification we define these terms as follows.  A
   confidentiality algorithm is "weak" if the effective key length of
   the cipher is 40 bits or less; it is "medium-strength" if the
   effective key length is strictly between 40 and 80 bits; and it is
   "strong" if the effective key length is 80 bits or greater.
   ("Effective key length" describes the computational effort required
   to break a cipher using the best-known cryptanalytic attack against
   that cipher.)

   A five-bit TS field allows up to 30 qualifiers for each of
   confidentiality and integrity (since "0" is reserved for "default"
   and "31" is reserved for "none", as shown above).  This document
   specifies three for confidentiality and two for integrity, leaving a
   lot of room for future specification.  Suggestions of qualifiers such
   as "fast", "medium-speed", and "slow" have been made, but such terms
   are difficult to quantify (and in any case are platform- and
   processor-dependent), and so have been left out of this initial
   specification.  The intention is that the TS terms be quantitative,
   environment-independent qualifiers of algorithms, as much as this is
   possible.

   Use of the qop_algs parameter as defined above is ultimately meant to
   be as follows.

    - TS values are specified at the IDUP-GSS-API level and are
      therefore portable across mechanisms.  Applications which know
      nothing about algorithms are still able to choose "quality" of
      protection for their message tokens.




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


    - MA values are specified at the mechanism level and are therefore
      portable across implementations of a mechanism.

    - IA values are specified at the implementation level (in user
      documentation, for example) and are therefore typically non-
      portable.  An application which is aware of its own mechanism
      implementation and the mechanism implementation of its intended
      P-IDU recipient, however, is free to use these values since they
      will be perfectly valid and meaningful for protecting IDUs between
      those entities.

   The receiver of a P-IDU must pass back to its calling application (in
   IDUP_Start_Unprotect()) a qop_algs parameter with all relevant fields
   set.  For example, if triple-DES has been specified by a mechanism as
   algorithm 8, then a receiver of a triple-DES-protected P-IDU must
   pass to its application (TS=1, IA=0, MA=8).  In this way, the
   application is free to read whatever part of the qop_algs parameter
   it understands (TS or IA/MA).

<span class="h4"><a class="selflink" id="section-1.2.5" href="#section-1.2.5">1.2.5</a>.  The Provision of Time</span>

   IDUP mechanisms should make provision in their protocols for the
   carrying of time information from originator to target(s).  That is,
   a target (a legitimate recipient) should get some indication during
   unprotection regarding the time at which the protection operation
   took place.  This is particularly important if the mechanism offers
   non-repudiation services because in some cases evidence verification
   may only be achievable if the time at which the evidence was
   generated is known.

   Depending upon the platform and resources available to the
   implementation, an IDUP environment may have access to a source of
   trusted (secure) time, untrusted (local) time, both kinds of time, or
   no time.  OBJECT IDs indicating such availability are returned by the
   IDUP_Establish_Env() call.  When starting a protection operation, an
   application may specify which time services it wishes to have applied
   to the IDU.  Similarly, for unprotection, an application may specify
   which kind of time (if any) to consult when the validity of the P-IDU
   is to be established.  Specifying both kinds of time is interpreted
   to mean that the calling application does not care which kind of time
   is used.

   The IDUP calls which use a time parameter specify the type of that
   parameter to be INTEGER.  This INTEGER is defined in all cases to be
   the number of seconds which have elapsed since midnight, January 1,
   1970, coordinated universal time.





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h2"><a class="selflink" id="section-2" href="#section-2">2</a>.  Interface Descriptions</span>

   This section describes the IDUP-GSS-API's operational interface,
   dividing the set of calls offered into five groups.  Credential
   management calls are related to the acquisition and release of
   credentials by API callers. Environment-level calls are related to
   the management of the security environment by an API caller.  Per-IDU
   calls are related to the protection or unprotection of individual
   IDUs in established security environments.  Special-purpose calls
   deal with unusual or auxiliary evidence generation/verification
   requirements.  Support calls provide extra functions useful to IDUP-
   GSS-API callers.  Table 2 groups and summarizes the calls in tabular
   fashion.

    Table 2:  IDUP-GSS-API Calls

      CREDENTIAL MANAGEMENT
      (see the calls given in <a href="#section-2.1">Section 2.1</a> of GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>])

      ENVIRONMENT-LEVEL CALLS
      IDUP_Establish_Env
      IDUP_Abolish_Env
      IDUP_Inquire_Env

      PER-IDU CALLS
      SE (SIGN,ENCRYPT) CALLS
         IDUP_SE_SingleBuffer_Protect
         IDUP_SE_SingleBuffer_Unprotect
         IDUP_SE_MultiBuffer_StartProtect
         IDUP_SE_MultiBuffer_EndProtect
         IDUP_SE_MultiBuffer_StartUnprotect
         IDUP_SE_MultiBuffer_EndUnprotect
         IDUP_SE_Process_Buffer
      EV (EVIDENCE) CALLS
         IDUP_EV_SingleBuffer_Generate
         IDUP_EV_SingleBuffer_Verify
         IDUP_EV_MultiBuffer_StartGenerate
         IDUP_EV_MultiBuffer_EndGenerate
         IDUP_EV_MultiBuffer_StartVerify
         IDUP_EV_MultiBuffer_EndVerify
         IDUP_EV_Process_Buffer
      GP (GENERAL PROTECTION) CALLS
         IDUP_Start_Protect
         IDUP_Protect
         IDUP_End_Protect
         IDUP_Start_Unprotect
         IDUP_Unprotect
         IDUP_End_Unprotect



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      SPECIAL-PURPOSE CALLS  (might not be supported by all mechanisms)
      IDUP_Form_Complete_PIDU

      SUPPORT CALLS
      IDUP_Acquire_cred_with_auth
      IDUP_Get_Token_Details
      IDUP_Get_Policy_Info
      IDUP_Cancel_Multibuffer_Op
      (see also the calls given in <a href="#section-2.4">Section 2.4</a> of GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>])

   In terms of conformance to this specification, IDUP-GSS-API
   implementations must support the credential management calls, the
   environment-level calls, some subset of the per-IDU calls, and the
   support calls (except where explicitly stated otherwise in <a href="#section-2.5">Section</a>
   <a href="#section-2.5">2.5</a>).  The subset of per-IDU calls supported will depend upon the
   underlying mechanisms supported and will typically be the SE calls,
   or the EV calls, or both.  As stated in <a href="#section-2.3.2.1">Section 2.3.2.1</a>,
   implementations are encouraged to support the more powerful GP calls
   to anticipate the future needs of applications developers, but this
   is not required for conformance.

<span class="h3"><a class="selflink" id="section-2.1" href="#section-2.1">2.1</a>.  Credential management calls</span>

<span class="h4"><a class="selflink" id="section-2.1.1" href="#section-2.1.1">2.1.1</a>.  Relationship to GSS-API</span>

   Credential management in IDUP-GSS-API is to be understood and used as
   described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].  The calls given in <a href="#section-2.1">Section 2.1</a> of
   GSS-API (including all associated parameters) are unchanged, although
   the interpretation of the cred_usage parameter in the GSS-API calls
   for IDUP purposes is as follows.

      ENCRYPT_ONLY    8
      DECRYPT_ONLY   16
      SIGN_ONLY      32
      VERIFY_ONLY    64

   The values above may be logically OR'ed together in any desired
   combination to restrict credential usage (where OR'ing all values
   results in NO_RESTRICTION).  Future possible values for this
   parameter are for further study.

   The call IDUP_Acquire_cred_with_auth has been added as a support call
   in this specification to permit authenticated credential acquirement;
   see <a href="#section-2.5.2">Section 2.5.2</a> for details.







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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h3"><a class="selflink" id="section-2.2" href="#section-2.2">2.2</a>.  Environment-level calls</span>

   This group of calls is devoted to the establishment and management of
   an environment for the purpose of IDU protection and unprotection.
   Before protecting or unprotecting any IDU, an application must call
   IDUP_Establish_Env() to initialize environment information and select
   the underlying IDUP-GSS mechanism to be used.  A series of protection
   or unprotection calls is made to process each IDU, the protection
   calls resulting in a P-IDU for each.  Finally, IDUP_Abolish_Env() is
   called to flush all environment information.

   Semantically, acquiring credentials and establishing an environment
   is (in many cases) analogous to logging in to a system -- it
   authenticates a local user to the system and gives that user access
   to a set of operations which can be performed.

<span class="h4"><a class="selflink" id="section-2.2.1" href="#section-2.2.1">2.2.1</a>.  Relationship to GSS-API</span>

   The set of calls described in this section is used in place of the
   calls described in <a href="#section-2.2">Section 2.2</a> of GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>], since those
   calls are specific to a session-oriented environment.

<span class="h4"><a class="selflink" id="section-2.2.2" href="#section-2.2.2">2.2.2</a>.  IDUP_Establish_Env call</span>

   Inputs: o  claimant_cred_handle CREDENTIAL HANDLE,
      -- NULL parameter specifies "use default"

   o  req_mech_type OBJECT IDENTIFIER,
      -- NULL parameter specifies "use default"
   o  req_environmentPolicies EnvironmentPolicies,
      -- NULL parameter specifies "use default"
   o  req_services SET OF OBJECT IDENTIFIER,
      -- GSS_C_NO_OID_SET requests full set of services available
      -- for req_mech_type

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  env_handle ENVIRONMENT HANDLE,
   o  actual_mech_type OBJECT IDENTIFIER,
      -- actual mechanism always indicated, never NULL
   o  actual_environmentPolicies EnvironmentPolicies,
      -- actual values always indicated, never NULL
   o  ret_services SET OF OBJECT IDENTIFIER,

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- environment-level information was successfully initialized,



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


      -- and IDU / P-IDU processing can begin.
   o  GSS_S_DEFECTIVE_CREDENTIAL
   o  GSS_S_NO_CRED
   o  GSS_S_CREDENTIALS_EXPIRED
      -- the credentials provided through claimant_cred_handle are
      -- no longer valid, so environment cannot be established.
   o  GSS_S_BAD_MECH
   o  GSS_S_FAILURE

   The following structures are defined to facilitate environment policy
   input and output:

   EnvironmentPolicies ::= SEQUENCE {
      confPolicy     [0] PolicyAndTime OPTIONAL,
      -- NULL parameter (on input) specifies "use default"
      integPolicy    [1] PolicyAndTime OPTIONAL,
      -- NULL parameter (on input) specifies "use default"
      evidencePolicy [2] PolicyAndTime OPTIONAL }
      -- NULL parameter (on input) specifies "use default"

   PolicyAndTime ::= SEQUENCE {
      policy             OBJECT IDENTIFIER,
      -- this environment-level policy identifier is separate from
      -- the policy provisions connected with credentials, if they exist
      time               INTEGER
      -- on input:  the policy rules available at the specified time
      -- on output: the time at which the policy rules came into effect
      -- (defined to be the number of seconds elapsed since midnight,
      -- January 1, 1970, coordinated universal time)
      endTime            INTEGER OPTIONAL }
      -- on input:  unused
      -- on output: the expiration time of the given policy rules

   This routine is used by an application which protects or unprotects
   IDUs.  Using information in the credentials structure referenced by
   claimant_cred_handle, IDUP_Establish_Env() initializes the data
   structures required to protect or unprotect IDUs.  The
   claimant_cred_handle, if non-NULL, must correspond to a valid
   credentials structure.

   This routine returns an env_handle for all future references to this
   environment; when protection, unprotection, or IDUP_Abolish_Env()
   calls are made, this handle value will be used as the input
   env_handle argument.  It is the caller's responsibility to establish
   a communications path to the intended recipients of the P-IDU, and to
   transmit the P-IDU to those recipients over that path.  This may
   occur subsequent to the IDUP_Abolish_Env() call.




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   The req_services parameter may be used by the calling application to
   request that data origin authentication with integrity,
   confidentiality with integrity, evidence generation, and/or evidence
   verification services be available in the established environment.
   Requests can also be made for "trusted" or "untrusted" time services.
   Requesting evidence generation or verification indicates that the
   calling application may wish to generate or verify evidence
   information for non-repudiation purposes (note:  an IDU protector may
   request that a flag be inserted into a P-IDU asking a recipient to
   provide an evidence of the type "non-repudiation of delivery";
   however, the IDUP-GSS-API cannot by itself guarantee that the
   evidence will be sent because there is no way to force a target to
   send an evidence_token back to the IDU protector).

   Not all features will be available in all underlying mech_types; the
   returned value of ret_services indicates, as a function of mech_type
   processing capabilities and the initiator-provided input OBJECT IDs,
   the set of features which will be available in the environment. The
   value of this parameter is undefined unless the routine's
   major_status indicates COMPLETE.  Failure to provide the precise set
   of services desired by the caller does not cause environment
   establishment to fail; it is the caller's choice to abolish the
   environment if the service set provided is unsuitable for the
   caller's use.  The returned mech_type value indicates the specific
   mechanism employed in the environment and will never indicate the
   value for "default".

   The following OBJECT IDs are defined for protection and unprotection
   services (the OBJECT ID iso.org.dod.internet.security.services,
   1.3.6.1.5.7, has been assigned by IANA, and some of the security
   services under that node are assigned as shown below).  It is
   recognized that this list may grow over time.

      PER_CONF = { 1.3.6.1.5.7.1.1 }
         -- perform data confidentiality (i.e., encrypt data)
      PER_CONF_FULL = { 1.3.6.1.5.7.1.3 }
         -- perform full confidentiality (i.e., encrypt data and sig)
         -- (may be used only when PER_DOA is requested simultaneously)
      PER_DOA  = { 1.3.6.1.5.7.3.1 }
         -- perform data origin authentication with data integrity
      PER_DOA_CIPH  = { 1.3.6.1.5.7.3.3 }
         -- perform DOA with DI over ciphertext (rather than plaintext)
         -- (may be used only when PER_CONF is requested simultaneously)
      PER_POO  = { 1.3.6.1.5.7.4.1 }
         -- perform (i.e., create) non-repudiable "proof of origin"
      PER_POD  = { 1.3.6.1.5.7.4.3 }
         -- perform (i.e., create) non-repudiable "proof of delivery"




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


      REC_CONF = { 1.3.6.1.5.7.1.2 }
         -- receive data confidentiality (i.e., decrypt data)
      REC_CONF_FULL = { 1.3.6.1.5.7.1.4 }
         -- receive full confidentiality (i.e., decrypt data and sig)
         -- (may be used only when REC_DOA is received simultaneously)
      REC_DOA  = { 1.3.6.1.5.7.3.2 }
         -- receive / verify DOA with data integrity
      REC_DOA_CIPH  = { 1.3.6.1.5.7.3.4 }
         -- verify DOA with DI over ciphertext (rather than plaintext)
         -- (may be used only when PER_CONF is received simultaneously)
      REC_POO  = { 1.3.6.1.5.7.4.2 }
         -- receive / verify "proof of origin"
      REC_POD  = { 1.3.6.1.5.7.4.4 }
         -- receive / verify "proof of delivery"
      TTIME    = { 1.3.6.1.5.7.7.1 }
         -- trusted time availability
      UTIME    = { 1.3.6.1.5.7.7.2 }
         -- untrusted time availability

   The PER_CONF return value (in the ret_services paramater) indicates
   whether the environment supports confidentiality services, and so
   informs the caller whether or not a request for encryption can be
   honored.  In similar fashion, the PER_DOA return value indicates
   whether DOA services are available in the established environment,
   and the PER_POO and PER_POD return values indicate whether evidence
   generation services are available.  The TTIME and UTIME values
   indicate whether trusted time and untrusted time are available for
   protection / unprotection services.

   Note that, unlike a GSS "context", an IDUP environment does not have
   an explicit lifetime associated with it.  Instead, it relies on the
   lifetime of the calling entity's credential (set by the caller in the
   GSS_Acquire_cred() call).  When the credential expires (or is
   explicitly deleted in any other way), no new operations are allowed
   in the IDUP environment (although operations which have begun, such
   as the Protection set of calls, can be taken to completion).















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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h4"><a class="selflink" id="section-2.2.3" href="#section-2.2.3">2.2.3</a>. IDUP_Abolish_Env call</span>

   Input:
   o  env_handle ENVIRONMENT HANDLE

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- the relevant environment-specific information was flushed.
   o  IDUP_S_NO_ENV
   o  GSS_S_FAILURE

   This call is made to flush environment-specific information. (Once an
   environment is established, cached credential and environment-related
   info. is expected to be retained until an IDUP_Abolish_Env() call is
   made or until the cred. lifetime expires.)  Attempts to perform IDU
   processing on a deleted environment will result in error returns.

<span class="h4"><a class="selflink" id="section-2.2.4" href="#section-2.2.4">2.2.4</a>. IDUP_Inquire_Env call</span>

   Input:
   o  env_handle ENVIRONMENT HANDLE,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  mech_type OBJECT IDENTIFIER,
      -- the mechanism supporting this environment
   o  environmentPolicies EnvironmentPolicies,
      -- the environment policies in effect
   o  ret_services SET OF OBJECT IDENTIFIER,

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- referenced environment is valid and mech_type and other return
      -- values describe the characteristics of the environment.
   o  GSS_S_CREDENTIALS_EXPIRED
   o  IDUP_S_NO_ENV
   o  GSS_S_FAILURE

   This routine provides environment-related information to the caller.







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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-20" ></span>
<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h3"><a class="selflink" id="section-2.3" href="#section-2.3">2.3</a>.  Per-IDU calls</span>

   This group of calls is used to perform IDU protection and
   unprotection processing on an established IDUP environment. Some of
   these calls may block pending network interactions (depending on the
   underlying mechanism in use).  These calls may be invoked by an IDU's
   protector or by the P-IDU's recipient.  Members of this group form
   pairs; the output from the protection types of calls is typically
   meant to be input to the unprotection types of calls.

   The per-IDU calls can support caller-requested data origin
   authentication with data integrity, confidentiality with data
   integrity, evidence, and evidence-requested-from-target services.

   The protection operations output a token which encapsulates all the
   information required to unprotect the IDU.  The token is passed to
   the target (possibly separate from the M-IDU) and is processed by the
   unprotection calls at that system.  Unprotection performs
   decipherment, DOA verification, evidence verification, or
   notification of evidence requested, as required.

   Each of the two main operations (protection and unprotection) may be
   separated into three parts:  "Start_Operation"; "Operation" (which
   may be called once for each buffer of input data); and
   "End_Operation".  This separation is available for the case where the
   IDU or P-IDU is to be processed one buffer at a time.
   "Start_Operation" allows the caller to specify or retrieve the
   appropriate "Quality" used during the processing.  "Operation" is
   concerned with the processing itself, receiving a buffer of input
   data and potentially returning a buffer of output data.
   "End_Operation" performs any required clean-up and creates the
   appropriate token or states whether the input token was verified.

   If the IDU or P-IDU is wholly contained in a single buffer, the
   three-part protection/unprotection processing need not be done.
   Instead, protection or unprotection can be accomplished using only a
   single call, simplifying application code.

<span class="h4"><a class="selflink" id="section-2.3.1" href="#section-2.3.1">2.3.1</a>.  Relationship to GSS-API</span>

   The set of calls described in this section is used in place of the
   calls GSS_GetMIC(), GSS_VerifyMIC, GSS_Wrap(), and GSS_Unwrap() which
   are specified in [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>], since those calls are specific to a
   session-oriented environment.







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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-21" ></span>
<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h4"><a class="selflink" id="section-2.3.2" href="#section-2.3.2">2.3.2</a>.  The "SE" Calls</span>

<span class="h5"><a class="selflink" id="section-2.3.2.1" href="#section-2.3.2.1">2.3.2.1</a>. IDUP_SE Purpose</span>

   The "SE" group of calls provides a very simple, high-level interface
   to underlying IDUP mechanisms when application developers need access
   only to signature and encryption protection/unprotection services.
   It includes both the single-buffer and multiple-buffer IDU cases and
   can be used for signing only, encrypting only, signing and encrypting
   (in either order, and with or without visibility of the resulting
   signature), and "clear signing" (where the data is not modified in
   any way and the signature itself is returned as a separate item).
   [Note that encapsulation occurs in all cases except for clear
   signing, so that these calls provide functionality similar to the
   GSS_Wrap call.]

   Note that the term "signing" is used in its most generic sense, not
   necessarily implying the use of public-key techniques.  This concept
   has also been called "sealing" in other contexts (e.g., in other
   standardization efforts).

   The SE calls may be viewed by mechanism implementors as an "API" to
   the more powerful GP calls defined later and so may be implemented as
   simple mapping functions to those calls (when those optional calls
   are supported).  Application callers, on the other hand, may find
   that the SE calls are all they currently need for many environments.
   At some time in the future when they have need of non-repudiation or
   "directed receipts" types of services, they may consider using the EV
   calls (or the GP calls -- when these are supported -- if complex and
   sophisticated combinations of services are required).  To assist in
   this migration path, mechanism implementors are encouraged to support
   the full set of IDUP calls (i.e., the SE, EV, and GP calls) even
   though some calling applications will only use the SE calls in the
   short term.

<span class="h5"><a class="selflink" id="section-2.3.2.2" href="#section-2.3.2.2">2.3.2.2</a>. IDUP_SE Parameter Bundles</span>

   The concept of "parameter bundles" is used in the calls presented in
   the following subsections in order to simplify their presentation and
   clarify their intended purpose and use.  See <a href="#section-2.3.4.1">Section 2.3.4.1</a> for a
   more complete description of parameter bundles.

   The following parameter bundles are used in the "SE" protection and
   unprotection sets of calls.







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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  Protect_Options PARAMETER BUNDLE
      o  protect_operation  INTEGER {
            sign_only              (0),
            encrypt_only           (1),
            sign_and_encrypt       (2),
            -- let mechanism choose order (and readability of signature)
            sign_then_encrypt_data (3),
            -- sign, then encrypt plaintext (leaving signature in clear)
            sign_then_encrypt_full (4),
            -- sign, then encrypt everything (including signature)
            encrypt_then_sign      (5),
            -- encrypt, then sign the ciphertext
            clear_sign_only        (6)
         } OPTIONAL,
      o  protect_oper_oid   OBJECT IDENTIFIER OPTIONAL,
         -- may be used in place of above parameter if OID is known
      o  sign_qop_alg      UNSIGNED INTEGER,
      o  sign_qop_algID    AlgorithmIdentifier, --overrides sign_qop_alg
      o  enc_qop_alg       UNSIGNED INTEGER,
      o  enc_qop_algID     AlgorithmIdentifier, --overrides enc_qop_alg
      o  idu_type_string    OCTET STRING,
         -- type of the IDU ("data", "e-mail doc", MIME type, etc.)
      o  pidu_type_string   OCTET STRING,
      o  mech_indep_encap_req BOOLEAN -- (see <a href="#appendix-A">Appendix A</a>)

   o  PIDU_Information PARAMETER BUNDLE
      o  protect_options    Protect_Options,
      o  originator_name    INTERNAL NAME,
      o  originator_role    Originator_Role, -- (see <a href="#section-2.3.4.1">Section 2.3.4.1</a>)
      o  protection_time    INTEGER,
   o  Bad_Target_Name PARAMETER BUNDLE,  -- same as in <a href="#section-2.3.3.2">Section 2.3.3.2</a>
      o  bad_targ_name     INTERNAL NAME,
      o  bad_targ_status   INTEGER,
         -- a status flag giving the reason for rejection of the name
         -- in bad_targ_name.  Specified reasons include:
         --  SYNTAX_INVALID        (0) the syntax of the name is invalid;
         --  NAME_UNRECOGNIZED     (1) the name is not recognized;
         --  NAME_AMBIGUOUS        (2) the name cannot be resolved;
         --  ACCESS_DENIED         (3) access to this target is denied;
         --  CERTIFICATE_NOT_FOUND (4) the encryption certificate of the
                                      target could not be found.

   o  Target_Info PARAMETER BUNDLE,      -- same as in <a href="#section-2.3.3.2">Section 2.3.3.2</a>
      o  targ_names        SET OF INTERNAL NAME,
      o  bad_targ_count    INTEGER,
      o  bad_target_names  SET OF Bad_Target_Name,





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h5"><a class="selflink" id="section-2.3.2.3" href="#section-2.3.2.3">2.3.2.3</a>. IDUP_SE major_status codes</span>

   The following major_status return codes are defined for the "SE"
   calls in this section:

   o  GSS_S_COMPLETE
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
      -- returned (by any SE call) to indicate that there is more output
      -- data than can fit into the supplied buffers.  The application
      -- should save the returned data and call again to retrieve the
      -- remaining output.
   o  IDUP_S_MORE_PIDU_NEEDED
      -- indicates that more PIDU data is needed for the StartUnprotect
      -- operation (e.g., so that PIDU_Information or initial_idu_buffer
      -- may be returned).
   o  IDUP_S_INCONSISTENT_PARAMS
   o  GSS_S_CREDENTIALS_EXPIRED
   o  IDUP_S_NO_ENV
   o  GSS_S_BAD_QOP
   o  GSS_S_FAILURE

   If Target_Info is used as an input parameter (e.g., if an encryption
   operation is being performed), the following major_status return code
   is also defined:

   o  IDUP_S_BAD_TARG_INFO

   Note for this return code that if one or more of the targets in
   targ_names cannot be used as a valid recipient of the P-IDU, these
   names will be returned in bad_targ_names (with associated status
   codes in bad_targ_status).  As long as at least one of the targets
   can be used, however, this does not cause this call to fail (i.e.,
   the failure code IDUP_S_BAD_TARG_INFO is not returned); it is the
   caller's choice to discontinue IDU protection if the target set which
   can be used is unsuitable for the caller's purposes.

<span class="h5"><a class="selflink" id="section-2.3.2.4" href="#section-2.3.2.4">2.3.2.4</a>. IDUP_SE_SingleBuffer_Protect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  Protect_Options PARAMETER BUNDLE,
   o  Target_Info PARAMETER BUNDLE,
   o  idu_buffer OCTET STRING
   o  additional_protection BOOLEAN
      -- TRUE if idu_buffer is the output of a previous protection
      -- operation (i.e., if this is the second (or higher) in a
      -- series of SE/EV protection calls)




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  pidu_buffer OCTET STRING,
   o  sig_token OCTET STRING
      -- used if Protect_Options is clear_sign_only

   Using the security environment referenced by env_handle, encrypt
   and/or sign the supplied IDU.  If "clear signing" is performed, the
   signature will be returned in sig_token and pidu_buffer may be empty
   (depends on underlying mechanism).

<span class="h5"><a class="selflink" id="section-2.3.2.5" href="#section-2.3.2.5">2.3.2.5</a>. IDUP_SE_SingleBuffer_Unprotect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  pidu_buffer OCTET STRING,
      -- may contain an IDU if sig_token is non-NULL (i.e., if
      -- clear_sign_only protection was applied)
   o  sig_token OCTET STRING

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  idu_buffer OCTET STRING,
      -- may be empty if clear_sign_only protection was applied (depends
      -- on underlying mechanism)
   o  PIDU_Information PARAMETER BUNDLE
   o  additional_unprotection BOOLEAN
      -- TRUE if idu_buffer should be input to another unprotection
      -- operation (i.e., if this should not be the last in a series
      -- of SE/EV unprotection calls)

   Using the security environment referenced by env_handle, decrypt
   and/or verify the supplied PIDU and return the contained IDU along
   with all available PIDU_Information.

<span class="h5"><a class="selflink" id="section-2.3.2.6" href="#section-2.3.2.6">2.3.2.6</a>. IDUP_SE_MultiBuffer_StartProtect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  Protect_Options PARAMETER BUNDLE,
   o  Target_Info PARAMETER BUNDLE,
   o  additional_protection BOOLEAN, -- (see <a href="#section-2.3.2.4">Section 2.3.2.4</a>)
   o  idu_size INTEGER               -- (see <a href="#section-2.3.4.2">Section 2.3.4.2</a>)






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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  initial_pidu_buffer OCTET STRING
      -- may be empty (depends on underlying mechanism)

   Using the security environment referenced by env_handle, initialize
   the data structures required to begin the process of signing and/or
   encrypting the IDU (which will be supplied in multiple buffers to the
   Process_Buffer call).

<span class="h5"><a class="selflink" id="section-2.3.2.7" href="#section-2.3.2.7">2.3.2.7</a>. IDUP_SE_MultiBuffer_EndProtect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  final_pidu_buffer OCTET STRING,
   o  sig_token OCTET STRING
      -- used if Protect_Options was clear_sign_only

   Using the security environment referenced by env_handle, complete the
   protection processing on the data and place the computed output in
   final_pidu_buffer and/or sig_token. Successful application of
   IDUP_SE_MultiBuffer_EndProtect() does not guarantee that unprotection
   can necessarily be performed successfully when the P-IDU arrives at
   the target (for example, it may be damaged in transit).

<span class="h5"><a class="selflink" id="section-2.3.2.8" href="#section-2.3.2.8">2.3.2.8</a>. IDUP_SE_MultiBuffer_StartUnprotect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  initial_pidu_buffer OCTET STRING,
   o  sign_qop_alg_in UNSIGNED INTEGER,
      -- used if Protect_Options was clear_sign_only (and calling
      -- application has prior knowledge of signing alg. applied);
      -- if NULL, then sig_token must be supplied
   o  sig_token OCTET STRING
      -- used if Protect_Options was clear_sign_only;
      -- if NULL, then sign_qop_alg_in must be supplied

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  PIDU_Information PARAMETER BUNDLE,
      -- returns all available information



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  initial_idu_buffer OCTET STRING
      -- may be empty

   Using the security environment referenced by env_handle, initialize
   the data structures required to begin the process of decrypting
   and/or verifying the PIDU (which will be supplied in multiple buffers
   to the Process_Buffer call).

   The parameters sign_qop_alg_in and sig_token should not both be
   supplied (i.e., they should not both be non-NULL).  If they are both
   non-NULL, however, sig_token is taken to be authoritative since this
   is the token created at protection time and therefore is guaranteed
   to carry the information needed to unprotect.

<span class="h5"><a class="selflink" id="section-2.3.2.9" href="#section-2.3.2.9">2.3.2.9</a>. IDUP_SE_MultiBuffer_EndUnprotect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  sig_token OCTET STRING  OPTIONAL
      -- used if Protect_Options was clear_sign_only and sig_token was
      -- not available when StartUnprotect was called

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  PIDU_Information PARAMETER BUNDLE,
      -- returns all available information
   o  final_idu_buffer OCTET STRING   -- may be empty
   o  additional_unprotection BOOLEAN -- (see <a href="#section-2.3.2.5">Section 2.3.2.5</a>)

   Using the security environment referenced by env_handle, complete the
   decryption and/or verification processing on the data and place any
   residual output in final_idu_buffer.

<span class="h5"><a class="selflink" id="section-2.3.2.10" href="#section-2.3.2.10">2.3.2.10</a>. IDUP_SE_Process_Buffer call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  input_buffer OCTET STRING,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  output_buffer OCTET STRING
      -- may be zero length (depends on underlying mechanism and
      -- corresponding Start() call and Protect_Options value)





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Using the security environment referenced by env_handle, continue the
   processing on the data in input_buffer and, if it is available, put
   any resulting output data in output_buffer.  The application calls
   this routine over and over again with new buffers of data until it
   has processed all the data buffers of the IDU/PIDU. It then calls the
   appropriate End() call to complete the processing.

<span class="h4"><a class="selflink" id="section-2.3.3" href="#section-2.3.3">2.3.3</a>.  The "EV" Calls</span>

<span class="h5"><a class="selflink" id="section-2.3.3.1" href="#section-2.3.3.1">2.3.3.1</a>. IDUP_EV Purpose</span>

   The "EV" group of calls provides a simple, high-level interface to
   underlying IDUP mechanisms when application developers need to deal
   only with evidence but not with encryption or integrity services. It
   includes both the single-buffer and multiple-buffer IDU cases and can
   be used for the generation and verification of evidence tokens
   embodying several different types of evidences.

   The following list of evidence types is supported. This list is by no
   means exhaustive and it is anticipated that it may be extended in
   future versions of this specification.

      "Non-repudiation of Origin" prevents a message creator's false
      denial of creating and sending a message.

      "Non-repudiation of Creation" prevents a message creator's false
      denial of creating a message.

      "Non-repudiation of Sender" prevents a message creator's false
      denial of sending a message (that was not necessarily created by
      the sender).

      "Non-repudiation of Delivery" prevents a message recipient's false
      denial of having received and looked at the content of a message.

      "Non-repudiation of Receipt" prevents a message recipient's false
      denial of having received a message (whose content was not
      necessarily looked at by the recipient).

      "Non-repudiation of Approval" prevents a message recipient's false
      denial of having approved the content of a received message.

   An evidence is provided in the form of a evidence token. Two forms of
   evidence tokens are supported:

      o  Tokens including the associated data,





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


      o  Tokens without included data (but with a unique reference to
         the associated data).

   Evidence tokens may be freely distributed. Any possessor of an
   evidence token (and of the associated data, if not included in the
   token) can verify the evidence if it has the appropriate credentials
   which include the definition of security policies (i.e., keys alone
   do not permit the verification of evidence tokens). Any holder of an
   evidence token may store it (along with the associated data, if not
   included in the token) for later verification.

   Calls that are specific to the support of evidence include:

   * Generate_token, which generates a non-repudiation token using the
     current environment. The generated token may consist of:

      1 - an evidence token
      2 - a token containing a request for an evidence, which carries
          information describing which evidence type should be generated
          by the recipient(s) and sent back to some entities (that may
          or may not include the sender).
      3 - a token containing an evidence token which is an answer to an
          evidence that has been previously requested.
      4 - a token including both an evidence and a request for another
          evidence to be provided.

   * Verify_evidence, which verifies the evidence token using the
     current environment. This operation returns a major_status code
     which can be used to determine whether the evidence contained in a
     token is complete (i.e., can be successfully verified (perhaps
     years) later). If a token's evidence is not complete, the token can
     be passed to form_complete_pidu to complete it.

   Additional useful calls for evidence services include:
   * IDUP_Get_token_details (see <a href="#section-2.5.3">Section 2.5.3</a>);
   * IDUP_Form_Complete_PIDU (see <a href="#section-2.4.2">Section 2.4.2</a>).

<span class="h5"><a class="selflink" id="section-2.3.3.2" href="#section-2.3.3.2">2.3.3.2</a>. IDUP_EV Parameters</span>

   The following parameter bundles are used in the "EV" protection and
   unprotection sets of calls.

   o  Nr_Options PARAMETER BUNDLE
      o  evidence_type  INTEGER {
                   no_evidence         (0)
                   -- used when request-only token desired
                   proof_of_receipt    (1),
                   proof_of_delivery   (2),



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


                   proof_of_approval   (3),
                   proof_of_creation   (4),
                   proof_of_sender     (5),
                   proof_of_origin     (6)
         } OPTIONAL,
      o  evidence_type_oid  OBJECT IDENTIFIER OPTIONAL,
         -- may be used in place of above parameter if OID is known
      o  evidence_validity_duration     INTEGER,
         -- duration_in_minutes
         -- DURATION_HOUR  = 60;
         -- DURATION_DAY   = 1440;
         -- DURATION_WEEK  = 10080;
         -- DURATION_MONTH = 43200;// 30 days
         -- DURATION_YEAR  = 525600;//365 days
      o  mech_indep_encap_req BOOLEAN -- (see <a href="#appendix-A">Appendix A</a>)

   o  Originator_Information PARAMETER BUNDLE
      o  token_generator_name INTERNAL NAME,
         -- obtained from the credentials of the originator
         -- (e.g., from its public key certificate)
      o  token_generator_role Originator_Role OPTIONAL,
         -- (see <a href="#section-2.3.4.1">Section 2.3.4.1</a>)
      o  protection_time      INTEGER OPTIONAL

   o  Bad_Target_Name  PARAMETER BUNDLE  -- (see <a href="#section-2.3.2.2">Section 2.3.2.2</a>)
      o  bad_targ_name          INTERNAL NAME,
      o  bad_targ_status        INTEGER
         -- a status flag giving the reason for rejection of the
         -- name in bad_targ_name

   o  Target_Info PARAMETER BUNDLE       -- same as in <a href="#section-2.3.2.2">Section 2.3.2.2</a>
      o  targ_names           SET OF INTERNAL NAME,
      o  bad_targ_count       INTEGER,
      o  bad_target_names     SET OF Bad_Target_Name

   o  Request_Features PARAMETER BUNDLE
      o  requested_evidence_type  INTEGER {
                 no_evidence         (0), - used when no token desired
                 proof_of_receipt    (1),
                 proof_of_delivery   (2),
                 proof_of_approval   (3), },
      o  nr_req_policy                        OBJECT IDENTIFIER,
      o  evidence_from                        Target_Info,
      o  evidence_to                          Target_Info,
      o  include_received_token_in_evidence   BOOLEAN

   The following data_type is used in the "EV" protection calls.




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  Nr_Operation  INTEGER {
            evidence_and_or_evidence_request  (1),
            returned_evidence                 (2) }

<span class="h5"><a class="selflink" id="section-2.3.3.3" href="#section-2.3.3.3">2.3.3.3</a>. IDUP_EV major_status codes</span>

   The following major_status return codes are defined for the "EV"
   calls in this section:

   o  GSS_S_COMPLETE
      -- indicates that the evidence is complete
   o  IDUP_S_INCOMPLETE
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
      -- returned (by any EV call) to indicate that there is more output
      -- data than can fit into the supplied buffers.  The application
      -- should save the returned data and call again to retrieve the
      -- remaining output.
   o  IDUP_S_INCONSISTENT_PARAMS
   o  GSS_S_CREDENTIALS_EXPIRED
   o  IDUP_S_NO_MATCH
   o  IDUP_S_NO_ENV
   o  GSS_S_FAILURE

   If Target_Info is used as an input parameter (i.e., if an evidence is
   being requested ), the following major_status return code is also
   defined:

   o  IDUP_S_BAD_TARG_INFO

   Note for this return code that if one or more of the targets in
   targ_names cannot be used as a valid recipient of the P-IDU, these
   names will be returned in bad_targ_names (with associated status
   codes in bad_targ_status).  As long as at least one of the targets
   can be used, however, this does not cause this call to fail (i.e.,
   the failure code IDUP_S_BAD_TARG_INFO is not returned); it is the
   caller's choice to discontinue IDU protection if the target set which
   can be used is unsuitable for the caller's purposes.

<span class="h5"><a class="selflink" id="section-2.3.3.4" href="#section-2.3.3.4">2.3.3.4</a>. IDUP_EV_SingleBuffer_Generate call</span>

   Inputs:
   o  env_handle                 ENVIRONMENT HANDLE,
   o  nr_operation               Nr_Operation,
   o  Nr_Options                 PARAMETER BUNDLE,
   o  idu_buffer                 OCTET STRING,
   o  form_complete_pidu         BOOLEAN,
      -- if TRUE the implementation will attempt to form a complete PIDU
   o  include_data_in_token      BOOLEAN,



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


      -- if TRUE, data provided in idu_buffer will be included in the
      -- generated token; if FALSE, the data will not be included
   o  Request_Features           PARAMETER BUNDLE
      -- the type of the evidence that is requested;
      -- policy under which the returned evidence should be generated;
      -- the recipients that are supposed to send back an evidence;
      -- the recipients that should receive the requested evidence;
      -- an indicator include_received_token_in_evidence:
      --   if TRUE, the evidence token incorporating the request will be
      --   included in the data for which recipients will generate
      --   evidence; if FALSE, evidence will be generated using only
      --   the data (and not the token incorporating the request).
   o  additional_protection BOOLEAN -- (see <a href="#section-2.3.2.4">Section 2.3.2.4</a>)

   Outputs:
   o  major_status               INTEGER,
   o  minor_status               INTEGER,
   o  token                      OCTET STRING,
   o  evidence_check             OCTET STRING,
      -- present only if an evidence is requested.  Consists of data to
      -- be used to verify the requested token(s) (if any) when they are
      -- received.

   Description:

   This operation generates a non-repudiation token associated with the
   data passed in an input buffer. Two kinds of operations can be
   performed (using the Nr_Operation parameter):

   a) generating a token that includes either an evidence only, or
      an evidence request only, or both an evidence and an evidence
      request;

   b) generating a response token for some recipients that includes an
      evidence generated as a response to a request (in this case the
      idu_buffer is used to enter the request token that was received).

   It is possible to request the generation of complete evidence. This
   may succeed or fail; if it fails, a subsequent call to
   Form_Complete_PIDU can be made.

<span class="h5"><a class="selflink" id="section-2.3.3.5" href="#section-2.3.3.5">2.3.3.5</a>. IDUP_EV_SingleBuffer_Verify call</span>

   Inputs:
   o  env_handle                     ENVIRONMENT HANDLE,
   o  token                          OCTET STRING,
   o  external_idu_buffer            OCTET STRING,
      -- if not present within the token



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  evidence_check                 OCTET STRING,
      -- present only if the input token is a response to a previous
      -- request for evidence (this parameter is used to validate that
      -- evidence).

   Outputs:
   o  major_status                   INTEGER,
   o  minor_status                   INTEGER,
   o  Nr_Options                     PARAMETER BUNDLE,
   o  Originator_Information         PARAMETER BUNDLE,
   o  Request_Features               PARAMETER BUNDLE,
   o  trusted_time_stamping_time     INTEGER OPTIONAL,
      -- present for informational purposes only
   o  complete_evidence_before       INTEGER OPTIONAL,
      -- if the major status code that is returned is
      -- IDUP_S_INCOMPLETE, IDUP_Form_Complete_PIDU should be called
      -- with the same token before this time.
      --    This may be required, for example, in order to insure that
      --    the time skew between the evidence generation time and
      --    the trusted time service's countersignature on the evidence
      --    falls within the interval allowed by the current NR policy.
   o  complete_evidence_after        INTEGER OPTIONAL,
      -- if the major status code that is returned is
      -- IDUP_S_INCOMPLETE, IDUP_Form_Complete_PIDU should be called
      -- with the same token after this time.
      --    This may be required, for example, to insure that all
      --    authorities involved in generating the evidence have passed
      --    the last time at which the current NR policy allows them to
      --    repudiate their keys.
   o  encapsulated_idu_buffer         OCTET STRING
      -- if the IDU was present within the token
   o  additional_unprotection BOOLEAN -- (see <a href="#section-2.3.2.5">Section 2.3.2.5</a>)

   Description:

   Verifies the validity and discloses the content of a nr_token.

   If the token containing the evidence to be verified was provided to
   the calling application by a partner responding to the calling
   application's request, then the calling application must pass the
   evidence check it received when it generated the request as a
   parameter along with the token it received from the partner.

   Output indicators are provided which give guidance about the time or
   times at which form_complete_pidu should be called; see the parameter
   descriptions for explanations of these indicators and their use. Note
   that the time specified by complete_evidence_before may be earlier
   than that specified by complete_evidence_after; in this case it will



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   be necessary to call form_complete_pidu twice.

   Because keys can be revoked or declared compromised, the return from
   verify_evidence cannot in all cases be a definitive "valid" or
   "invalid"; sometimes "conditionally valid" may be returned, depending
   upon the policy in use. IDUP_S_INCOMPLETE will be returned, for
   example, if:

    - the interval during which the generator of the evidence may
      permissibly declare his key invalid has not yet expired (and
      therefore it is possible that the evidence may be declared invalid
      in the future), or

    - trusted time is required for verification, and the time obtained
      from the token is not trusted.

<span class="h5"><a class="selflink" id="section-2.3.3.6" href="#section-2.3.3.6">2.3.3.6</a>. IDUP_EV_MultiBuffer_StartGenerate call</span>

   Inputs:
   o  env_handle                 ENVIRONMENT HANDLE,
   o  nr_operation               Nr_Operation,
   o  Nr_Options                 PARAMETER BUNDLE,
   o  form_complete_pidu         BOOLEAN,
   o  include_data_in_token      BOOLEAN,
   o  idu_size                   INTEGER, -- (see <a href="#section-2.3.4.2">Section 2.3.4.2</a>)
   o  Request_Features           PARAMETER BUNDLE
   o  additional_protection BOOLEAN -- (see <a href="#section-2.3.2.4">Section 2.3.2.4</a>)

   Outputs:
   o  major_status               INTEGER,
   o  minor_status               INTEGER,
   o  initial_pidu_buffer        OCTET STRING
      -- may be empty (depends on underlying mechanism)

   Description:

   Using the security environment referenced by env_handle, initialize
   the data structures required to begin the generation of a token. The
   IDU will be supplied in multiple buffers to the
   IDUP_EV_Process_Buffer call). Two kinds of operations can be
   performed (using the Nr_Operation parameter) :

     a) generating a token that includes either an evidence only, or
        an evidence request only, or both an evidence and an evidence
        request.






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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


     b) generating a return token for some recipients that includes an
        evidence generated as a response to a request. In that case the
        received token will be passed into the subsequent
        IDUP_EV_Process_Buffer calls. The boolean include_data_in_token
        is ignored as the output will always be contained in a single
        token. The Request_Features are ignored in that case at this
        time in order to keep things simple and to avoid the piggy-
        backing that is theoretically possible.

   It is possible to request the generation of complete evidence. This
   may succeed or fail; if it fails, a subsequent call to
   Form_Complete_PIDU can be made.

<span class="h5"><a class="selflink" id="section-2.3.3.7" href="#section-2.3.3.7">2.3.3.7</a>. IDUP_EV_MultiBuffer_EndGenerate call</span>

   Inputs:
   o  env_handle                 ENVIRONMENT HANDLE

   Outputs:
   o  major_status               INTEGER,
   o  minor_status               INTEGER,
   o  final_pidu                 OCTET STRING,
   o  token                      OCTET STRING,
   o  evidence_check             OCTET STRING
      -- present only if an evidence is requested.

   Description:

   Using the security environment referenced by env_handle, provide the
   requested token or the final P-IDU. A token will be generated if
   encapsulation was not requested; otherwise, the final P-IDU is
   provided.

<span class="h5"><a class="selflink" id="section-2.3.3.8" href="#section-2.3.3.8">2.3.3.8</a>. IDUP_EV_MultiBuffer_StartVerify call</span>

   Inputs:
   o  env_handle                     ENVIRONMENT HANDLE,
   o  token                          OCTET STRING,
   o  evidence_check                 OCTET STRING,
      -- present only if an evidence has been previously requested.

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER







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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Description:

   Using the security environment referenced by env_handle, initialize
   the data structures required to begin the process of verifying the
   token.  The P-IDU will be supplied in multiple buffers to the
   IDUP_EV_Process_Buffer call.

<span class="h5"><a class="selflink" id="section-2.3.3.9" href="#section-2.3.3.9">2.3.3.9</a>. IDUP_EV_MultiBuffer_EndVerify call</span>

   Input:
   o  env_handle                     ENVIRONMENT HANDLE

   Outputs:
   o  major_status                   INTEGER,
   o  minor_status                   INTEGER,
   o  Nr_Options                     PARAMETER BUNDLE,
   o  Originator_Information         PARAMETER BUNDLE,
   o  Request_Features               PARAMETER BUNDLE,
   o  trusted_time_stamping_time     INTEGER OPTIONAL,
   o  complete_evidence_before       INTEGER OPTIONAL,
   o  complete_evidence_after        INTEGER OPTIONAL,
   o  idu_buffer                     OCTET STRING
      -- if the IDU was present within the token
   o  additional_unprotection BOOLEAN -- (see <a href="#section-2.3.2.5">Section 2.3.2.5</a>)

   Description:

   Using the security environment referenced by env_handle, complete the
   verification processing on the data and provide verified output
   parameters to the caller when the major status code is either:

   o GSS_S_COMPLETE or
   o IDUP_S_INCOMPLETE

<span class="h5"><a class="selflink" id="section-2.3.3.10" href="#section-2.3.3.10">2.3.3.10</a>. IDUP_EV_Process_Buffer call</span>

   Inputs:
   o  env_handle         ENVIRONMENT HANDLE,
   o  input_buffer       OCTET STRING

   Outputs:
   o  major_status       INTEGER,
   o  minor_status       INTEGER,
   o  output_buffer      OCTET STRING
      -- may be zero length (depends on underlying mechanism and
      -- corresponding Generate () call and options
      -- (e.g., data_included_in_token)




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Description:

   Using the security environment referenced by env_handle, continue the
   processing on the data in input_buffer and, if it is available, put
   any resulting output data in output_buffer. The application calls
   this routine over and over again with new buffers of data until it
   has processed all the data buffers of the IDU/PIDU. It then calls the
   appropriate End() call to complete the processing.

<span class="h4"><a class="selflink" id="section-2.3.4" href="#section-2.3.4">2.3.4</a>. The "GP" Calls</span>

   The "GP" group of calls provides a powerful interface to flexible and
   sophisticated combinations of protection and unprotection services.
   This power and flexibility, however, necessitates a more complex
   interface than either the SE or the EV calls. Furthermore, such
   combinations of services are not needed in many of the security
   mechanisms in common use today (although this is likely to change as
   time goes on).  The GP calls are therefore specified to be OPTIONAL
   and need not be supported by IDUP-conformant implementations.  Note,
   however, that the structure of IDUP tokens should be such that the
   SE/EV and GP calls may be used interchangably by the receiver.

<span class="h5"><a class="selflink" id="section-2.3.4.1" href="#section-2.3.4.1">2.3.4.1</a>. Parameter Bundles</span>

   The concept of "parameter bundles" is used in the calls presented in
   the following subsections in order to simplify their presentation and
   clarify their intended purpose and use (note that specific language
   bindings may or may not use parameter bundles for its actual calling
   conventions).  A parameter bundle is simply a set of closely-related
   parameters of a call which are either all used by / available to the
   calling application or all not used by / unavailable to the calling
   application.  These parameters may be all input parameters, all
   output parameters, or any combination of the two.

   An example use envisioned for parameter bundles in a language such as
   C would be as a structure, where individual parameters in the bundle
   are structure members.  The calling application wishing to use a
   particular bundle would then allocate the appropriate structure
   variable, assign the desired input values to the appropriate members,
   and pass the address of the structure as the bundle "parameter".  On
   output, the values of the appropriate output members may be read.  An
   application not wishing to use a particular bundle (or one which is
   satisfied with default values for all input parameters of the bundle
   and which doesn't care about output values), can pass NULL as the
   bundle "parameter".  From the mechanism implementor's perspective, if
   a parameter bundle is not supported (for example, if it represents a
   security service which is not supported by the implementation), then
   any non-NULL value passed as the bundle parameter will generate an



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   error status return code.

   [Note that the parameter bundles given below, except where explicitly
   referenced by the SE and EV calls, are specific to the (optional) GP
   calls.  Thus, these bundles need not be supported by IDUP-conformant
   implementations if the GP calls are not supported.]

   The following parameter bundles are used in the subsequent protection
   and unprotection sets of calls.  A parameter preceded by "(I)" is an
   input parameter; one preceded by "(O)" is an output parameter; one
   preceded by neither is an input if the bundle itself is an input and
   is an output if the bundle itself is an output; one preceded by "(X)"
   is the opposite:  an output if the bundle itself is an input and an
   input if the bundle itself is an output.

      o Mech_Specific_Info PARAMETER BUNDLE
        -- actual parameters included in this bundle are defined by (and
        -- specific to) the underlying mechanism

      o Sensitivity PARAMETER BUNDLE,
        -- actual parameters included in this bundle are defined by (and
        -- specific to) the underlying mechanism, but may include
        -- codified values for "Unclassified", "Secret", "Top Secret",
        -- and so on

      o Service_Creation_Info PARAMETER BUNDLE
        -- actual parameters included in this bundle are defined by (and
        -- specific to) the underlying mechanism, but it is mandatory
        -- that they include at least service_id and Quality

      o Service_Verification_Info PARAMETER BUNDLE
        -- actual parameters included in this bundle are defined by (and
        -- specific to) the underlying mechanism, but it is mandatory
        -- that they include at least service_id and Quality

      o  Quality PARAMETER BUNDLE
         o  qop_algs  UNSIGNED INTEGER,
         o  qop_algID AlgorithmIdentifier, --overrides qop_algs
         o  validity  UNSIGNED INTEGER,
            -- protection guaranteed to be valid until time specified
         o  policy_id OBJECT IDENTIFIER,
            -- security policy under which protection is/was carried out
         o  allow_policy_mapping BOOLEAN,
            -- determines whether mapping between policy IDs is allowed
         o  actual_policy_time INTEGER
            -- time at which the above policy rules came into effect





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      o  Idu_Information PARAMETER BUNDLE,
         o  idu_type_oid OBJECT IDENTIFIER,
         o  idu_type_string OCTET STRING,
         o  idu_title OCTET STRING,
         o  idu_sensitivity Sensitivity,
         o  pidu_type_oid OBJECT IDENTIFIER,
         o  pidu_type_string OCTET STRING,
         o  pidu_title OCTET STRING,
         o  pidu_sensitivity Sensitivity,

      o  Prot_Information PARAMETER BUNDLE,
         o  originator_name INTERNAL NAME,
         o  originator_role Originator_Role,
         o  idu_information Idu_Information,
         o  protection_time INTEGER,

      o  Originator_Role PARAMETER BUNDLE, -- role in organization
         o  domain_name                 INTERNAL NAME OPTIONAL,
         o  role                        PRINTABLE STRING,
         o  role_info_is_authenticated  BOOLEAN
            -- TRUE if info. is authenticated (e.g., inside a cert.)

      o  Special_Conditions PARAMETER BUNDLE,
         o  prot_oper_id INTEGER,
         o  form_complete_pidu BOOLEAN,
            -- input to protection operations for evidence generation
         o  pidu_in_solic_service BOOLEAN,
            -- in protection operations, used as input for service
            -- solicitation to request that receiver include the
            -- received PIDU when generating the response.  In unprot.
            -- operations, used as output to inform receiver that PIDU
            -- should be included when generating the response.
         o  use_trusted_time BOOLEAN,
         o  use_untrusted_time BOOLEAN,
         o  mech_indep_encap_req BOOLEAN -- (see <a href="#appendix-A">Appendix A</a>)

      o  Bad_Target_Name PARAMETER BUNDLE,
         o  (O) bad_targ_name INTERNAL NAME,
         o  (O) bad_targ_status INTEGER,
                -- a status flag giving the reason for rejection of
                -- the name in bad_targ_name. Specified reasons include:
                --    SYNTAX_INVALID        (0)
                --       the syntax of the name is invalid;
                --    NAME_UNRECOGNIZED     (1)
                --       the name is not recognized;
                --    NAME_AMBIGUOUS        (2)
                --       the name cannot be resolved;
                --    ACCESS_DENIED         (3)



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


                --       access to this target is denied;
                --    CERTIFICATE_NOT_FOUND (4)
                --       the encryption certificate of the target could
                --       not be found.

      o  Target_Info PARAMETER BUNDLE,
         o      targ_names       SET OF INTERNAL NAME,
         o  (O) bad_targ_count   INTEGER,
         o  (O) bad_target_names SET OF Bad_Target_Name,

      o  General_Service_Data PARAMETER BUNDLE,
         o      target_info Target_Info,
         o  (X) unencapsulated_token OCTET STRING,
                -- zero length if encapsulation_request is TRUE
         o  (O) minor_status INTEGER,

   Three types of protection services are defined in IDUP.  These are:

      1. perform unsolicited service (i.e., act on a locally-generated
         service request),
      2. perform solicited service (i.e., act on a remotely-generated
         service request), and
      3. perform service solicitation (i.e., send a service request to
         the remote end).

   As an originator, applying data confidentiality with data integrity,
   or data origin authentication with data integrity, or proof of origin
   evidence is an example of service type 1.  As a target, creating a
   proof of delivery (i.e., receipt) evidence token as the result of a
   request received from the originator is an example of service type 2.
   Finally, as an originator, submitting a request that one or more
   targets return a receipt for the data sent is an example of service
   type 3.

   The first four parameters in the Prot_Service parameter bundle
   pertain to all service types; the fifth parameter is used if and only
   if service type 2 is desired; parameters 6-8 are used if and only if
   service type 3 is desired.

      o  Prot_Service PARAMETER BUNDLE
         o  (I) prot_service_type INTEGER,
         o  (I) service_id OBJECT IDENTIFIER,
         o  (I) quality Quality, -- NULL specifies default Quality
         o  (I) general_service_data General_Service_Data,
         o  (I) service_creation_info Service_Creation_Info,
         o  (I) service_to SET OF INTERNAL NAME,
         o  (O) service_verification_info Service_Verification_Info,
         o  (O) service_verification_info_id INTEGER,



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Also, three types of unprotection services are defined.  These are:

      1. receive unsolicited service (i.e., process unrequested
         remotely-generated service),
      2. receive solicited service (i.e., process remotely-generated
         response to locally-generated request), and
      3. receive service solicitation (i.e., process req. from rem. end)

   As a target, unprotecting an encrypted message, or verifying the
   originator's proof of origin is an example of service type 1.  As an
   originator, verifying a proof of delivery which you requested from a
   target is an example of service type 2.  Finally, as a target,
   receiving a request from an originator for a proof of delivery is an
   example of service type 3.

   The first four parameters in the Unprot_Service parameter bundle
   pertain to all service types; parameters 5-6 are used if and only if
   service type 2 is required; parameters 7-8 are used only if service
   type 3 is required.

      o  Unprot_Service PARAMETER BUNDLE
         o  (O) unprot_service_type INTEGER,
         o  (O) service_id OBJECT IDENTIFIER,
         o  (O) quality Quality,
                -- actual Quality specified (never NULL)
         o  (O) general_service_data General_Service_Data,
         o  (O) service_verification_info_id INTEGER,
         o  (I) service_verification_info Service_Verification_Info,
         o  (O) service_to SET OF INTERNAL NAME,
         o  (O) service_creation_info Service_Creation_Info,

<span class="h5"><a class="selflink" id="section-2.3.4.2" href="#section-2.3.4.2">2.3.4.2</a>. IDUP_Start_Protect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  Mech_Specific_Info PARAMETER BUNDLE,
      -- NULL selects the mechanism-defined default values
   o  Idu_Information PARAMETER BUNDLE,
   o  Special_Conditions PARAMETER BUNDLE,
   o  encapsulation_request BOOLEAN,
   o  single_idu_buffer OCTET STRING,
      -- non-zero length for this buffer means that Protect/End_Protect
      -- won't be called (i.e., entire IDU is contained in this buffer)
   o  idu_size INTEGER,
      -- size (in bytes) of the IDU to be protected;
      -- may be "-1" signifying "UNKNOWN" (note that some mechanisms
      -- may not support encapsulation in such a case)
   o  Target_Info PARAMETER BUNDLE,



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  Services_to_Perform SET OF Prot_Service,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  midu_buffer OCTET STRING,
      -- zero length if encapsulation_request is TRUE;
      -- may be zero length otherwise (depends on underlying mechanism)
   o  pidu_buffer OCTET STRING,
      -- zero length if encapsulation_request is FALSE;
      -- may be zero length otherwise (depends on underlying mechanism)

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- the protection process can begin (or has completed, if
      -- single_idu_buffer has non-zero length).
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
   o  GSS_S_CREDENTIALS_EXPIRED
   o  IDUP_S_NO_ENV
   o  IDUP_S_ENCAPSULATION_UNAVAIL
   o  IDUP_S_SERVICE_UNAVAIL
   o  IDUP_S_REQ_TIME_SERVICE_UNAVAIL
   o  IDUP_S_UNKNOWN_OPER_ID
   o  GSS_S_BAD_QOP
   o  IDUP_S_BAD_TARG_INFO
   o  GSS_S_FAILURE

   Using the security environment referenced by env_handle, initialize
   the data structures required to begin the process of protecting the
   IDU buffers.  The caller requests specific protection services by
   supplying the appropriate Prot_Service parameter bundles in
   Services_to_Perform.  Each service is able to return a minor status
   code to the calling application, if necessary.

   The calling application, knowing the size of the IDU it wishes to
   protect and the buffer size which it has available to it, can choose
   to input the entire IDU in a single buffer and omit the subsequent
   IDUP_Protect() and IDUP_End_Protect() calls.  Furthermore, the
   application can request that the resulting M-IDU be encapsulated in
   the token -- so that the token contains the entire P-IDU -- rather
   than having it be returned separately in midu_buffer.  Encapsulation,
   however, may not be supported by all underlying mechanisms or
   implementations; if this is the case, the
   IDUP_S_ENCAPSULATION_UNAVAIL major status code will be returned and
   M-IDU will be returned in midu_buffer.






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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   For those mechanisms which allow or require multiple stages of
   processing, each producing a different aspect of protection for the
   IDU, the operation identifier prot_oper_id is used to specify which
   stage is currently being requested by the application.  An example
   where this would be useful is a mechanism which implements the signed
   Message Security Protocol [<a href="#ref-MSP" title="&quot;Message Security Protocol&quot;">MSP</a>].  As another example, a mechanism may
   choose to do a digital signature in two stages:  one for the hashing
   of the message and another for the signature on the hash.  The
   calling application would therefore use the protection set of calls
   on the IDU in stage 1 and then use the protection set of calls on the
   token (from stage 1) in stage 2.

   Note that prot_oper_id is simply an integer (1, 2, 3, ..., n, where
   "n" is the number of stages as defined by the mechanism (typically 1
   or 2)).  The calling application uses this parameter to indicate to
   the underlying mechanism whether it wishes to do stage 1 of
   protection / unprotection processing, or stage 2, and so on. Portable
   applications may pass "0" to let the mechanism choose the stage (note
   that mechanism implementers may still iterate when prot_oper_id = 0
   (e.g., use output as next input, et cetera).

   If one or more of the targets in targ_names cannot be used as a valid
   recipient of the P-IDU, these names will be returned in
   bad_targ_names (with associated status codes in bad_targ_status).  As
   long as at least one of the targets can be used, this does not cause
   this call to fail; it is the caller's choice to discontinue IDU
   protection if the target set which can be used is unsuitable for the
   caller's purposes.  Note that each Prot_Service parameter bundle can
   also input a list of targ_names; this is used if a separate list is
   to be used for that service only (the general list of targets is to
   be used for all services unless overridden in this way).

<span class="h5"><a class="selflink" id="section-2.3.4.3" href="#section-2.3.4.3">2.3.4.3</a>. IDUP_Protect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  input_buffer OCTET STRING,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  output_buffer OCTET STRING
      -- may be zero length if encapsulation_request was set to TRUE in
      -- IDUP_Start_Protect() (depends on underlying mechanism)

   Return major_status codes:
   o  GSS_S_COMPLETE
   o  IDUP_S_NO_ENV



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  GSS_S_FAILURE

   Using the security environment referenced by env_handle, continue the
   protection processing on the data in input_buffer and, if the
   underlying mechanism defines this, put any resulting P-IDU/M-IDU data
   in output_buffer.  The application calls this routine over and over
   again with new buffers of data until it has protected all the data
   buffers of the IDU.  It then calls IDUP_End_Protect() to complete the
   protection processing.

<span class="h5"><a class="selflink" id="section-2.3.4.4" href="#section-2.3.4.4">2.3.4.4</a>. IDUP_End_Protect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  Services_to_Perform SET OF Prot_Service,
   o  final_midu_buffer OCTET STRING,
      -- zero length if encapsulation_request was set to TRUE in
      -- IDUP_Start_Protect(), in which case pidu is used
   o  final_pidu_buffer OCTET STRING,
      -- zero length if encapsulation_request was set to FALSE in
      -- IDUP_Start_Protect(), in which case token and midu are used

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- protection has successfully completed and the resulting P-IDU
      -- is ready for transfer.  If defined by the underlying mechanism,
      -- final_midu_buffer will contain any residual M-IDU data.
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
   o  IDUP_S_NO_ENV
   o  GSS_S_FAILURE

   Using the security environment referenced by env_handle, complete the
   protection processing on the data and place the computed output in
   final_pidu_buffer (or final_midu_buffer and the unencapsulated_token
   parameter for each Prot_Service).  If a service was requested from
   one or more targets in Start_Protect() - and if this is supported by
   the underlying mechanism - Service_Verification_Info will hold
   whatever data is necessary for the mechanism to verify a service
   returned by a target (unprotector) of the P-IDU.  Successful
   application of IDUP_End_Protect() does not guarantee that the
   corresponding unprotection set of calls can necessarily be performed
   successfully when the P-IDU arrives at the target (for example, it
   may be damaged in transit).




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<hr class='noprint'/><!--NewPage--><pre class='newpage'><span id="page-44" ></span>
<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h5"><a class="selflink" id="section-2.3.4.5" href="#section-2.3.4.5">2.3.4.5</a>. IDUP_Start_Unprotect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  Mech_Specific_Info PARAMETER BUNDLE,
      -- NULL selects the mechanism-defined default values
   o  single_pidu_buffer OCTET STRING,
      -- non-zero length for this buffer means that IDUP_Unprotect() and
      -- IDUP_End_Unprotect() will not be called (i.e., the entire P-IDU
      -- (if encapsulation is used) or M-IDU (if encap. is not used)
      -- is contained in this buffer)
   o  partial_pidu_buffer OCTET STRING,
      -- may be an arbitrary-sized piece of the full pidu (if the
      -- application's buffer isn't large enough to hold entire pidu).
      -- Used if pidu_buffer will be input a buffer at a time (except
      -- that the final buffer must be passed in final_pidu_buffer
      -- rather than partial_pidu_buffer).  Only one of
      -- single_pidu_buffer and partial(final)_pidu_buffer can have
      -- nonzero length.
   o  final_pidu_buffer OCTET STRING,
   o  Special_Conditions PARAMETER BUNDLE,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  Services_to_Receive SET OF Unprot_Service,
   o  Prot_Information PARAMETER BUNDLE,
   o  single_idu_buffer OCTET STRING,
      -- if this buffer has non-zero length, then service processing has
      -- been completed on the data in single_pidu_buffer
   o  initial_idu_buffer OCTET STRING,
      -- holds any data from partial(final)_pidu_buffer which has been
      -- unprotected; remaining data will be returned by Unprotect and
      -- End_Unprotect as they are called with successive buffers of
      -- pidu
   o  Service_Verification_Info PARAMETER BUNDLE,
      -- used only if target is on "service_to" list in Unprot_Service
   o  service_verification_info_id INTEGER,
      -- used only if target is on "service_to" list in Unprot_Service












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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Return major_status codes:
   o  GSS_S_COMPLETE
      -- unprotection processing can begin (or has completed, if
      -- single_idu_buffer has non-zero length).
   o  IDUP_S_INCOMPLETE
      -- used only if single_idu_buffer has non-zero length.
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
   o  IDUP_S_MORE_PIDU_NEEDED
   o  GSS_S_DEFECTIVE_TOKEN
   o  IDUP_S_INAPPROPRIATE_CRED
   o  IDUP_S_INCONSISTENT_PARAMS
   o  IDUP_S_DEFECTIVE_VERIF
   o  IDUP_S_NO_MATCH
   o  IDUP_S_SERVICE_UNAVAIL
   o  IDUP_S_REQ_TIME_SERVICE_UNAVAIL
   o  IDUP_S_SERV_VERIF_INFO_NEEDED
   o  GSS_S_CREDENTIALS_EXPIRED
   o  IDUP_S_NO_ENV
   o  IDUP_S_UNKNOWN_OPER_ID
   o  GSS_S_BAD_QOP
      -- the qop_algs value specified in P-IDU for at least one of the
      -- services is unavailable in the local mechanism, so processing
      -- cannot continue.
   o  GSS_S_BAD_MIC
   o  IDUP_S_BAD_DOA_KEY
   o  IDUP_S_BAD_KE_KEY
   o  IDUP_S_BAD_ENC_IDU
   o  GSS_S_FAILURE

   Using the security environment referenced by env_handle, initialize
   the data structures required to begin the process of unprotecting a
   P-IDU.  The caller will be alerted as to which services were applied
   to the P-IDU in the returned Services_to_Receive set of parameters.

   If encapsulation was not used by the originator, it is the receiving
   application's responsibility to separate the received P-IDU into a
   M-IDU and one or more unencapsulated_token buffers (the latter being
   input in separate Unprot_Service bundles in the Services_to_Receive
   parameter).  These unencapsulated_token buffers should be input
   before the M-IDU (i.e., in IDUP_Start_Unprotect) or after the M-IDU
   (i.e., in IDUP_End_Unprotect) as appropriate; this order may be
   dictated, for example, by their placement in the in-coming message.

   If unprotection will be applied more than once to a given P-IDU, it
   is the responsibility of the calling application to remember if a
   service solicitation has been responded to previously (i.e., if the
   requested service has already been generated / sent for that P-IDU)
   and thus ignore subsequent solicitations on unprotect.



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   The time flags indicate whether to consult trusted, untrusted, or no
   time (if both flags are FALSE) during the unprotection operation.  If
   the current time is not to be checked, then unprotection may be
   successful even if the protector's key has expired since the P-IDU
   was generated (that is, if the Validity period -- as specified in the
   Quality parameter bundle -- has expired).

   If the underlying mechanism supports it and if this information is
   contained in the P-IDU, information regarding the originator (that
   is, the entity which used the protection set of calls to generate
   this P-IDU) is returned in the Prot_Information parameter bundle.

<span class="h5"><a class="selflink" id="section-2.3.4.6" href="#section-2.3.4.6">2.3.4.6</a>. IDUP_Unprotect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  input_buffer OCTET STRING

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  output_buffer OCTET STRING

   Return major_status codes:
   o  GSS_S_COMPLETE
   o  IDUP_S_NO_ENV
   o  GSS_S_FAILURE

   Using the security environment referenced by env_handle, continue the
   unprotection processing on the data in input_buffer, putting any
   resulting IDU data in output_buffer (if required).

<span class="h5"><a class="selflink" id="section-2.3.4.7" href="#section-2.3.4.7">2.3.4.7</a>. IDUP_End_Unprotect call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  Prot_Information PARAMETER BUNDLE,
   o  Services_to_Receive SET OF Unprot_Service,
   o  final_idu_buffer OCTET STRING,
   o  Service_Verification_Info PARAMETER BUNDLE,
      -- used only if target is on "service_to" list in Unprot_Service
   o  service_verification_info_id INTEGER,
      -- used only if target is on "service_to" list in Unprot_Service




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Return major_status codes:
   o  GSS_S_COMPLETE
      -- residual IDU data will be returned in final_idu_buffer.
   o  IDUP_S_INCOMPLETE
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
   o  GSS_S_BAD_MIC
   o  IDUP_S_BAD_DOA_KEY
   o  IDUP_S_BAD_KE_KEY
   o  IDUP_S_BAD_ENC_IDU
   o  IDUP_S_NO_ENV
   o  GSS_S_FAILURE

   Using the security environment referenced by env_handle, complete the
   unprotection processing on the data and return the appropriate status
   code.  If there is any residual IDU data it will be returned in
   final_idu_buffer.

   If the IDUP_S_INCOMPLETE major status value is returned, all output
   parameters are conditionally valid; the unprotection set of functions
   will have to be called again (perhaps with a complete P-IDU, as
   produced by IDUP_Form_Complete_PIDU) in order to get valid values for
   all parameters.  "Conditional validity" may arise, for example, if
   all relevant certificates verify correctly, but it is not yet past
   the time up to which the current policy allows the authorities
   involved to repudiate their keys.

   If the underlying mechanism supports it and if this information is
   contained in the token, information regarding the originator (that
   is, the entity which used the protection set of calls to generate
   this token) is returned in the Prot_Information parameter bundle.
   This information may or may not be omitted if it was returned by the
   IDUP_Start_Unprotect() call.

   Note that, unlike GSS-API, IDUP-GSS-API does not incorporate the
   concept of error tokens transferred between sender and recipient
   since the protection and unprotection of an IDU may be separated by
   an indefinite amount of time and may or may not be performed by the
   same entity.

<span class="h3"><a class="selflink" id="section-2.4" href="#section-2.4">2.4</a>. Special-Purpose Calls</span>

<span class="h4"><a class="selflink" id="section-2.4.1" href="#section-2.4.1">2.4.1</a>.  Relationship to GSS-API</span>

   The special-purpose call described in this section has no analog in
   GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].  This call is used to complete a P-IDU (that is,
   to generate a P-IDU which can be unprotected successfully with no
   additional data at any time during its validity period).  This call
   may not be supported by all underlying IDUP mechanisms or



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   implementations.

<span class="h4"><a class="selflink" id="section-2.4.2" href="#section-2.4.2">2.4.2</a>. IDUP_Form_Complete_PIDU call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,
   o  single_pidu_buffer OCTET STRING,
   o  partial_pidu_buffer OCTET STRING,
      -- an arbitrary-sized piece of the full pidu token.  Used if pidu
      -- will be input a buffer at a time (except that the final buffer
      -- must be passed in final_pidu_buffer rather than
      -- partial_pidu_buffer).  Only one of single_pidu_buffer and
      -- partial(final)_pidu_buffer can have nonzero length.
   o  final_pidu_buffer OCTET STRING,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  pidu_token_out OCTET STRING -- the augmented PIDU; may be complete
   o  call_again_before INTEGER,
   o  call_again_after INTEGER,
   o  trusted_time_stamping_time INTEGER  -- for information only

   Return major_status codes:
   o  GSS_S_COMPLETE
   o  IDUP_S_MORE_OUTBUFFER_NEEDED
   o  IDUP_S_INCOMPLETE
      -- generation of the P-IDU is not yet complete.  The application
      -- should call this function again before the time given in
      -- call_again_before (if not NULL), or after the time given in
      -- call_again_after (if not NULL), or both (if neither are NULL).
   o  IDUP_S_INCONSISTENT_PARAMS
   o  IDUP_S_SERVICE_UNAVAIL
   o  GSS_S_DEFECTIVE_TOKEN
   o  GSS_S_FAILURE

   Form_Complete_PIDU is used primarily by the evidence services; in
   particular, when the evidence token itself does not contain all the
   data required for its verification and it is anticipated that some of
   the data not stored in the token may become unavailable during the
   interval between generation of the evidence token and verification
   unless it is stored in the token. The Form_Complete_PIDU operation
   gathers the missing information and includes it in the token so that
   verification can be guaranteed to be possible at any future time.

   This call generates a PIDU which can be unprotected successfully with
   no additional data at any time during its validity period.  [For
   background information on the notion of "complete" evidence, see



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   "CORBA Security Service v1.2 Draft D02", 18 June 1997.]

   Using the security environment referenced by env_handle, complete the
   generation of a P-IDU token and return the appropriate status value
   along with the completed token (if available).  Such a call may be
   used, for example, for the purpose of batch evidence generation on an
   "evidence server".  A local machine may be able to use the protection
   set of calls to fill out most of an evidence token and then send a
   number of these to a batch processor which forms the complete
   evidence tokens (perhaps by adding a certification path, or a
   timestamp and signature from a timestamping authority).  As another
   example, on the receiving end an application may make such a call in
   order to collect all the information necessary to unprotect a P-IDU
   (such as all relevant certificates and Certificate Revocation Lists);
   this will ensure that the calls to the unprotection set of operations
   will be entirely local (i.e., can be performed off-line) and fast.

   Note that the complete P-IDU generated will be formed using trusted
   time if this is available in the environment referenced by env_handle
   and will use untrusted time or no time otherwise (depending on what
   is available).

<span class="h3"><a class="selflink" id="section-2.5" href="#section-2.5">2.5</a>.  Support calls</span>

<span class="h4"><a class="selflink" id="section-2.5.1" href="#section-2.5.1">2.5.1</a>.  Relationship to GSS-API</span>

   Support calls in IDUP-GSS-API are to be understood and used as
   described in GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].  The calls described in <a href="#section-2.4">Section 2.4</a>
   of GSS-API (including all associated parameters) are unchanged.  The
   following additional calls are specified for IDUP-GSS-API.

2.5.2:  IDUP_Acquire_cred_with_auth call

   Inputs:
   o  desired_name INTERNAL NAME,
      -- NULL requests locally-determined default
   o  authenticator OCTET STRING
      -- string which authenticates the caller claiming to be
      -- desired_name
   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 BIT STRING
      -- actual values which can be used currently correspond to those
      -- given in <a href="#section-2.1.1">Section 2.1.1</a> (i.e.,
      --    ENCRYPT_ONLY    8
      --    DECRYPT_ONLY   16



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


      --    SIGN_ONLY      32
      --    VERIFY_ONLY    64
      -- with the values logically OR'ed together in any desired
      -- combination to restrict credential usage; OR'ing all values
      -- results in NO_RESTRICTION).
      -- Future possible values for this parameter are for further
      -- study (note that the type of this parameter is BIT STRING
      -- (rather than INTEGER as in GSS_Acquire_cred) to facilitate
      -- such future expansion).

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  output_cred_handle  CREDENTIAL HANDLE,
   o  actual_mechs SET OF OBJECT IDENTIFIER,
   o  actual_cred_usage   BIT STRING,
   o  lifetime_rec INTEGER
      -- in seconds, or reserved value for INDEFINITE

   This call (which need not be supported by all underlying mechanisms
   or implementations) is identical to the GSS_Acquire_cred call, with
   the exception of the added input parameter "authenticator" and the
   added output parameter "actual_cred_usage". The authenticator
   (typically a password, pass-phrase, or PIN) is used to authenticate
   the caller claiming to be desired_name to the underlying GSS (or
   mechanism) code.  The actual_cred_usage specifies the actual uses
   available for these credentials; it is up to the caller to determine
   if this is sufficient for its purposes.

   Implementations that are able to authenticate the caller in some
   other way are encouraged to use the GSS_Acquire_cred call; those
   having no other means available to them, or wishing to explicitly
   authenticate the caller at the time of credential acquisition, should
   use the IDUP_Acquire_cred_with_auth call (if supported).

   Note that the return major status codes for this call are identical
   to those given for the GSS_Acquire_cred call.  If the authentication
   fails (e.g., the wrong authenticator is supplied for the given
   desired_name), the major status GSS_S_FAILURE is returned (along with
   an appropriate minor status code).

<span class="h4"><a class="selflink" id="section-2.5.3" href="#section-2.5.3">2.5.3</a>. IDUP_Get_token_details call</span>

   Inputs:
   o  token                  OCTET STRING,
   -- all the data to be returned shall be within the first 4 KB of
   -- the token; hence, a single call is needed. It is not necessary
   -- to provide the entire token when the token includes the IDU.



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   o  mech_type              SET OF OBJECT IDENTIFIER
   -- input if known (typically SET will contain a single member)

   Outputs:
   o  major_status                       INTEGER,
   o  minor_status                       INTEGER,
   o  actual_mech_type                   OBJECT IDENTIFIER,
   o  data_included_in_token             BOOLEAN,
      -- true if the data is encapsulated
   o  idu_size                           INTEGER,
   o  has_SE_protection                  BOOLEAN,
   o  has_EV_protection                  BOOLEAN,
   o  PIDU_Information                   PARAMETER BUNDLE,
   o  nr_policy                          OBJECT IDENTIFIER,
      -- this and subsequent parameters pertain only to evidence tokens
   o  Nr_Options                         PARAMETER BUNDLE,
   o  Originator_Information             PARAMETER BUNDLE,
   o  time_stamping_time                 INTEGER  OPTIONAL
   o  Request_Features                   PARAMETER BUNDLE,
      -- describes the included request, if any.
   o  requested_evidence_back            BOOLEAN,
      -- true if this is an evidence generated in response to a
      -- previously-sent request
   o  evidence_check                     OCTET STRING,
      -- meaningful if the boolean above is true

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- input_token could be parsed for all relevant fields.
   o  GSS_S_CREDENTIALS_EXPIRED
   o  GSS_S_DEFECTIVE_TOKEN
      -- the mechanism type could be parsed, but either the other fields
      -- could not be determined from the input_token, or their values
      -- did not correspond to valid values for that mechanism.
   o  GSS_S_FAILURE
      -- the mechanism type was missing or corrupted.

   IDUP_Get_token_details() is used to return to an application the
   attributes that correspond to a given input token.  Since IDUP-GSS-
   API tokens are meant to be opaque to the calling application, this
   function allows the application to determine information about the
   token without having to violate the opaqueness intention of IDUP. Of
   primary importance is the mechanism type, which the application can
   then use as input to the IDUP_Establish_Env() call in order to
   establish the correct environment in which to have the token
   processed.





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   If all tokens are framed as suggested in <a href="./rfc2078#section-3.1">Section&nbsp;3.1 of [RFC-2078]</a>
   (mandated in the Kerberos V5 GSS mechanism [<a href="./rfc1964">RFC 1964</a>] and in the SPKM
   GSS Mechanism [<a href="./rfc2025">RFC 2025</a>]), then any mechanism implementation should
   be able to return the mech_type parameter for any uncorrupted input
   token. If the mechanism implementation whose IDUP_Get_token_details()
   function is being called does recognize the token, it can return any
   further relevant information in the other token attributes, as
   specified.  In particular, this function can set has_SE_protection if
   the SE calls may be used to unprotect it, or has_EV_protection if the
   EV calls may be used to unprotect it, or both if both kinds of
   protection have been applied (so that SE or EV calls may be used in
   any order for unprotection) [note that GP calls, when supported,
   should be usable for unprotection of any IDUP token].

   IDUP_Get_token_details (which need not be supported by all underlying
   mechanisms or implementations) gives only a hint about the content of
   the token, there is no integrity check of any kind performed.
   Regardless of the token type, it is possible to check that this
   information is correct only by doing a proper unprotection of the
   token.  It is recommended that IDUP callers supply a token buffer at
   least 4 KB in length in order to ensure that the desired data can
   easily flow across this interface.

   The OID of the mechanism and whether the token contains the
   associated data is returned. In addition the size of the associated
   data, whether inside or outside the token, is included if known.
   [Note:  data size will typically be unknown if the data was protected
   using multibuffer calls.  A value of "-1" may be used to indicate
   "UNKNOWN".]

   When the input token contains only an evidence generated
   spontaneously, the following is returned:
    - the evidence type;
    - the Non-Repudiation policy under which the evidence was generated;
    - the name of the generator of the evidence;
    - the date and time when the evidence was generated (if available);
    - the date and time when it was time stamped (if available).

   When the input token contains only an evidence generated in response
   to  a request from another entity, the following additional
   information is returned:
    - an indicator to state that this evidence relates to a request;
    - a string significant for the requester that will allow him to
      check whether the answer corresponds to the requested evidence.

   When the input token only contains a request, the following is
   returned:
    - the name of the requestor of the evidence,



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    - the date and time when the request was made,
    - the evidence type to send back,
    - the non-repudiation policy under which the evidence to send back
      should be generated,
    - the names of the recipients which should generate and distribute
      the requested evidence,
    - the names of the recipients to whom the requested evidence should
      be sent after it has been generated.

   When the input token contains both evidence and a request, an
   indicator is returned describing whether the new evidence should be
   generated using only the data in the input token, or using both the
   data and the evidence in the input token.

   When the input token contains only CONF and DOA services, the
   PIDU_Information bundle is returned.  Other relevant parameters (such
   as idu_size and time_stamping_time) may also be returned if this data
   is available.

<span class="h4"><a class="selflink" id="section-2.5.4" href="#section-2.5.4">2.5.4</a>. IDUP_Get_policy_info call</span>

   Inputs:
   o  policy_id OBJECT IDENTIFIER

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,
   o  policy_version INTEGER,
   o  policy_effective_time INTEGER,
   o  policy_expiry_time INTEGER,
   o  supported_services SET OF Service_Descriptor,
      -- services supported by this particular policy_id (equal to the
      -- intersection of the services supported by the mechanisms
      -- listed in supported_mechanisms)
   o  supported_mechanisms SET OF Mechanism_Descriptor
      -- mechanisms supported by this particular policy_id

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- policy_id recognized; all relevant fields have been returned.
   o  GSS_S_FAILURE
      -- the policy_id was not recognized.

   This call (which need not be supported by all underlying mechanisms
   or implementations) allows the application to retrieve information
   pertaining to a given policy_id.  Policies define the following:
      -  rules for the protection of IDUs, such as trusted third
         parties which may be involved in P-IDU generation, the roles in



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         which they may be involved, and the duration for which the
         generated P-IDU is valid;

      -  rules for the unprotection of P-IDUs, such as the interval
         during which a trusted third party may legitimately declare its
         key to have been compromised or revoked; and

      -  rules for adjudication, such as which authorities may be used
         to adjudicate disputes.

   The policy itself may be used by an adjudicator when resolving a
   dispute.  For example, the adjudicator might refer to the policy to
   determine whether the rules for generation of the P-IDU have been
   followed.

   The following parameter bundles are associated with this call.

      o  Service_Descriptor PARAMETER BUNDLE,
         o  service_type OBJECT IDENTIFIER,
         o  service_validity_duration INTEGER,
         o  must_use_trusted_time BOOLEAN

      o  Mechanism_Descriptor PARAMETER BUNDLE,
         o  mechanism_type OBJECT IDENTIFIER,
         o  Authority_List PARAMETER BUNDLE,
         o  maximum_time_skew INTEGER
            -- maximum permissible difference between P-IDU generation
            -- time and the time of countersignature from a time
            -- service (if required).  This parameter is unused if
            -- trusted time is not required.

      o  Authority_List PARAMETER BUNDLE,
         o  authority_name INTERNAL NAME,
         o  authority_role OCTET STRING,
         o  last_revocation_check_offset INTEGER
            -- may be 0, greater than 0, or less than 0.  The value of
            -- this parameter is added to P-IDU generation time to
            -- get latest time at which the mechanism will check to
            -- see if this authority's key has been revoked.

   An example of the use of the last parameter in Authority_List is as
   follows.  If an authority has a defined last_revocation_check_offset
   of negative one hour, then all revocations taking effect earlier than
   one hour before the generation of a P-IDU will render that P-IDU
   invalid; no revocation taking place later than one hour before the
   generation of the P-IDU will affect the P-IDU's validity.





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   Note that both the maximum_time_skew and the
   last_revocation_check_offset values are given in minutes.

<span class="h4"><a class="selflink" id="section-2.5.5" href="#section-2.5.5">2.5.5</a>. IDUP_Cancel_multibuffer_op call</span>

   Inputs:
   o  env_handle ENVIRONMENT HANDLE,

   Outputs:
   o  major_status INTEGER,
   o  minor_status INTEGER,

   Return major_status codes:
   o  GSS_S_COMPLETE
      -- operation cancelled; state purged.
   o  GSS_S_FAILURE
      -- unable to cancel operation; state retained.

   This call (which need not be supported by all underlying mechanisms
   or implementations) allows the application to cancel a multibuffer
   operation prior to normal completion (e.g., subsequent to calling
   Start_operation and zero or more Process_operation, but prior to
   calling End_operation).  When successful, this call purges any
   internal state information which would have been used to continue
   processing for the full set of multibuffer calls.

<span class="h2"><a class="selflink" id="section-3" href="#section-3">3</a>.  Related Activities</span>

   In order to implement the IDUP-GSS-API atop existing, emerging, and
   future security mechanisms, the following is necessary:

    - object identifiers must be assigned to candidate IDUP-GSS-API
      mechanisms and the name types which they support; and

    - concrete data element (i.e., token and parameter bundle) formats
      must be defined for candidate mechanisms.

   Calling applications must implement formatting conventions which will
   enable them to distinguish IDUP-GSS-API P-IDUs from other IDUs in
   their environment.

   Concrete language bindings are required for the programming
   environments in which the IDUP-GSS-API is to be employed.








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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


<span class="h2"><a class="selflink" id="section-4" href="#section-4">4</a>.  Acknowledgments</span>

   Many thanks are due to Tim Moses and Dhanya Thakkar of Entrust
   Technologies, Denis Pinkas of Bull, and David Kurn of Tandem
   Computers for a number of helpful comments and contributions.

<span class="h2"><a class="selflink" id="section-5" href="#section-5">5</a>. Security Considerations</span>

   Security issues are discussed throughout this memo.

<span class="h2"><a class="selflink" id="section-6" href="#section-6">6</a>. REFERENCES</span>

   [<a id="ref-MSP">MSP</a>]       U.S. National Security Agency, "Message Security
               Protocol", Secure Data Network System SDN.701, March
               1994.

   [<a id="ref-RFC-1421">RFC-1421</a>]  Linn, J., "Privacy Enhancement for Internet Electronic
               Mail:  Part I: Message Encryption and Authentication
               Procedures", <a href="./rfc1421">RFC 1421</a>, February 1993.

   [<a id="ref-RFC-2078">RFC-2078</a>]  Linn, J., "Generic Security Service Application Program
               Interface, Version 2", <a href="./rfc2078">RFC 2078</a>, January 1997..

   [<a id="ref-RFC 1964">RFC 1964</a>]  Linn, J, "The Kerberos Version 5 GSS-API Mechanism", <a href="./rfc1964">RFC</a>
               <a href="./rfc1964">1964</a>, June 1996.

   [<a id="ref-RFC 2025">RFC 2025</a>]  Adams, C., "The Simple Public-Key GSS-API Mechanism
               (SPKM)", <a href="./rfc2025">RFC 2025</a>, October 1996.

   [ISO/IEC]   2nd ISO/IEC CD 13888-1, "Information technology -
               Security techniques - Non-repudiation - Part 1:  General
               Model", ISO/IEC JTC 1/SC 27, May 30, 1995

<span class="h2"><a class="selflink" id="section-7" href="#section-7">7</a>. Author's Address</span>

   Carlisle Adams
   Entrust Technologies
   750 Heron Road, Suite E08,
   Ottawa, Ontario, CANADA  K1V 1A7

   Phone:  +1 613.247.3180
   EMail: cadams@entrust.com









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APPENDIX  A:  MECHANISM-INDEPENDENT TOKEN FORMAT

   This appendix specifies the use, for IDUP-GSS-API tokens, of the
   mechanism-independent level of encapsulating representation for
   tokens given in <a href="#section-3.1">Section 3.1</a> of GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].  The
   representation given there incorporates an identifier of the
   mechanism type to be used when processing the associated tokens. Use
   of that octet format is recommended to the designers of IDUP-GSS-API
   implementations based on various mechanisms so that tokens can be
   interpreted unambiguously at IDUP-GSS-API peers. It is recognized,
   however, that for interoperability purposes with peers not using IDUP
   for specific IDU protection/unprotection protocols, the encapsulating
   representation may need to be omitted.  (In such a case it is
   necessary that the underlying mechanism provides some sort of
   internal or external identification that allows it to recognize its
   own tokens.)  When the mechanism-independent level of encapsulating
   representation is not desired, callers SHOULD set
   mech_indep_encap_req to FALSE (note that some underlying mechanisms
   may default this parameter to FALSE).

   For purely descriptive purposes, the following simple ASN.1 structure
   is used to illustrate the structural relationships among token and
   tag objects.  For interoperability purposes, token and tag encoding
   shall be performed using the concrete encoding procedures described
   in <a href="#section-3.1">Section 3.1</a> of GSS-API [<a href="./rfc2078" title="&quot;Generic Security Service Application Program Interface, Version 2&quot;">RFC-2078</a>].

          -- top-level token definition to frame different mechanisms

          IDUP-GSS-API DEFINITIONS ::=
          BEGIN
          MechType ::= OBJECT IDENTIFIER

          Token ::= [APPLICATION 0] IMPLICIT SEQUENCE {
                  thisMech MechType,
                  token ANY DEFINED BY thisMech
                     -- contents mechanism-specific
                  }
          END













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APPENDIX  B:  EXAMPLES OF IDUP USE

   This appendix provides examples of the use of IDUP to do IDU
   protection and unprotection.  It should not be regarded as
   constrictive to implementations or as defining the only means through
   which IDUP-GSS-API functions can be realized with particular
   underlying technology, and does not demonstrate all IDUP-GSS-API
   features.

   Most of the examples below only illustrate the use of CONF/DOA
   protection services.  Note that when both CONF/DOA and Evidence
   services are required, calling applications may use a series of SE
   and EV calls, or may use the GP calls (when these are supported).
   Using the former approach implies multiple calls (e.g., the SE calls
   are used to protect some data and the resulting token is then input
   to the EV calls to add evidence information), but some callers may
   find this to be more attractive than coding to the GP calls because
   of the simpler SE/EV interface.  Depending upon the underlying
   mechanism, the series of SE/EV calls may result in a single token
   that can be unprotected using the SE and EV calls in any order (for
   example, because it is a single ASN.1 SEQUENCE that incorporates all
   the specified protection services at one level), or the series may
   result in a token that can only be unprotected in the reverse order
   of protection (for example, because each SE/EV output token was
   effectively embedded in the token of the subsequent call). The
   IDUP_Get_token_details call can assist callers in determining how to
   unprotect any received token.

<span class="h3"><a class="selflink" id="appendix-B.1" href="#appendix-B.1">B.1</a>.  Simple Mechanism, Single Buffer</span>

   To illustrate the simplest possible case, consider an underlying IDUP
   mechanism which does straightforward encryption/decryption and
   signing/verification only using public-key techniques; none of the
   other possible services, such as creation of proof-of-origin
   evidence, requests for proof-of-delivery evidence, or use of trusted
   time, are supported.  PEM[RFC-1421] is one example of a mechanism
   which fits this description.  Furthermore (again for simplicity),
   assume that encapsulation is chosen by the calling application during
   IDU protection.

   Such a mechanism would likely use the "SE" set of IDUP-GSS-API calls.
   The following parameter bundle uses and defaults would therefore be
   specified in the relevant IDUP mechanism document.








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   SENDER:

   Set
      env_handle                = environment handle in use;
      idu_buffer                = data buffer;
      Target_Info.targ_names    = receiver names;
      Protect_Options           = as necessary;

   Call
      IDUP_SE_SingleBuffer_Protect() with above input parameters

   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         Target_Info.Bad_Targ_Name,
      (as required) for more detailed information.

   Send
      Output parameter pidu_buffer to receiver.

   RECEIVER (any parameters not listed below are given the value NULL):

   Set
      env_handle         = environment handle in use;
      pidu_buffer        = received data buffer;

   Call
      IDUP_SE_SingleBuffer_Unprotect() with above input parameters
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
      (as required) for more detailed information

   Utilize
      PIDU_Information.Protect_Options.Protect_Operation,
         (to determine which services were applied by the originator)
      PIDU_Information.Protect_Options.sign_qop_alg / enc_qop_alg,
         (to determine the corresponding qualities of the services)
      Prot_Information.originator_name,
         (to determine the name of the originator)
      Prot_Information.protection_time,
         (to determine when the IDU was protected)
      idu_buffer
         (to retrieve the unprotected data).







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<span class="h3"><a class="selflink" id="appendix-B.2" href="#appendix-B.2">B.2</a>.  Simple Mechanism, Single Buffer (Again)</span>

   To illustrate a slight variation on the simplest possible case,
   assume that everything is as in the previous scenario except that the
   "GP" calls are used.

   The following parameter bundle uses and defaults would therefore be
   specified in the relevant IDUP mechanism document.

   Mech_Specific_Info
      - NOT USED (the only acceptable input, therefore, is NULL)

   Idu_Sensitivity
      - NOT USED (the only acceptable input, therefore, is NULL)

   Service_Creation_Info
      - NOT USED (the only acceptable input, therefore, is NULL)

   Service_Verification_Info
      - NOT USED (the only acceptable input, therefore, is NULL)

   Quality
      - the qop_algs parameter must be supported, with a suitable
        DEFAULT value specified;
      - suitable DEFAULT values for validity, policy_id, and
        allow_policy_mapping must be specified (it may be an
        implementation option as to whether these parameters are
        explicitly modifiable by the calling application, or whether
        NULLs are the only acceptable input)

    Idu_Information
      - the idu_type parameter must have a value representing a suitable
        IDU type (for example, in PEM a value representing the string
        "<a href="./rfc822">RFC822</a>" or some other valid "Content-Domain" would be used),
        with a suitable DEFAULT value specified;
      - the idu_title parameter is NOT USED (the only acceptable input,
        therefore, is NULL)

   Prot_Information
      - the originator_name and idu_type (in Idu_Information) parameters
        are read from the encapsulating information and output by
        IDUP_Start_Unprotect;
      - all other parameters are NOT USED (and therefore NULL)

   Special_Conditions
      - NOT USED (the only acceptable input, therefore, is NULL)





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   Target_Info
      - this bundle is used as described in IDUP; no DEFAULT values are
        specified

   General_Service_Data
      - the unencapsulated_token parameter is used if
        encapsulation_request is FALSE;
      - the minor_status parameter is used to return minor status values
        as specified by the mechanism document

   Prot_Service
      - the prot_service_type parameter may have a value of "1"
        ("perform unsolicited service") or NULL (which specifies the
        DEFAULT value of "1");
      - the service_id parameter must have a value representing
        "PER_CONF" or "PER_DOA";
      - the parameters Service_Creation_Info, service_to,
        Service_Verification_Info, and service_verification_info_id are
        NOT USED (and therefore NULL)

   Unprot_Service
      - the unprot_service_type parameter will always have a value of
        "1" ("receive unsolicited service");
      - the service_id parameter will have a value representing
        "REC_CONF" or "REC_DOA";
      - the parameters service_verification_info_id,
        Service_Verification_Info, service_to, and
        Service_Creation_Info, are NOT USED (and therefore NULL)

   Assuming that the calling application has only a single buffer of
   data to protect/unprotect, the following sequence of operations must
   be performed by the sender and receivers (subsequent to environment
   establishment).

   SENDER (any parameters not listed below are given the value NULL):

   Set
      env_handle                           = environment handle in use;
      encapsulation_request                = TRUE;
      single_idu_buffer                    = data buffer;
      Target_Info.targ_names               = receiver names;
      P_Services.Prot_Service_1.service_id = PER_CONF;
      P_Services.Prot_Service_2.service_id = PER_DOA;

   Call
      IDUP_Start_Protect() with above input parameters





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   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         Target_Info.bad_targ_names / Target_Info.bad_targ_status,
         P_Services.Prot_Service_1.General_Service_Data.minor_status,
         P_Services.Prot_Service_2.General_Service_Data.minor_status
      (as required) for more detailed information.

   Send
      Output parameter pidu_buffer to receiver.


   RECEIVER (any parameters not listed below are given the value NULL):

   Set
      env_handle         = environment handle in use;
      single_pidu_buffer = received data buffer;

   Call
      IDUP_Start_Unprotect() with above input parameters
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         R_Services.Unprot_Service_1.General_Service_Data.minor_status,
         R_Services.Unprot_Service_2.General_Service_Data.minor_status
      (as required) for more detailed information

   Utilize
      R_Services.Unprot_Service_1/2.service_id,
         (to determine which services were applied by the originator)
      R_Services.Unprot_Service_1/2.Quality,
         (to determine the corresponding qualities of the services)
      Prot_Information.originator_name,
         (to determine the name of the originator)
      single_idu_buffer
         (to retrieve the unprotected data).

<span class="h3"><a class="selflink" id="appendix-B.3" href="#appendix-B.3">B.3</a>.  Simple Mechanism, Multiple Buffers</span>

   To illustrate the next step up in complexity, consider the use of the
   simple IDUP mechanism described in B.2 above with multiple data
   buffers.  In particular, consider the case in which a large data file
   is to be signed.  For this example, assume that the calling
   application does not wish to use encapsulation.

   Note that the parameter bundle uses and defaults are as specified in
   B.2. above.




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   SENDER (any parameters not listed below are given the value NULL):

   Set
      env_handle                           = environment handle in use;
      encapsulation_request                = FALSE;
      P_Services.Prot_Service.service_id   = PER_DOA;

   Call
      IDUP_Start_Protect() with above input parameters
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         P_Services.Prot_Service.General_Service_Data.minor_status
      (as required) for more detailed information.

   For each buffer of input data:
      Set
         input_buffer = buffer
      Call
         IDUP_Protect() with above input parameter
      Check
         major_status.  If not GSS_S_COMPLETE, check
            minor_status

   Call
      IDUP_End_Protect()
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         P_Services.Prot_Service.General_Service_Data.minor_status
      (as required) for more detailed information.

   Send
      P_Services.Prot_Service.General_Service_Data.unencapsulated_token,
      and the file for which the signature was calculated (if required),
      to receiver.

   RECEIVER (any parameters not listed below are given the value NULL):

   Set
      env_handle            = environment handle in use;
      R_Services.Unprot_Service_1.General_Service_Data.
      unencapsulated_token  = received unencapsulated token;

   Call
      IDUP_Start_Unprotect() with above input parameters
   Check
      major_status.  If not GSS_S_COMPLETE, check



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


         minor_status,
         R_Services.Unprot_Service_1.General_Service_Data.minor_status,
      (as required) for more detailed information

   For each buffer of input data:
      Set
         input_buffer = buffer
      Call
         IDUP_Unprotect() with above input parameter
      Check
         major_status.  If not GSS_S_COMPLETE, check
            minor_status

   Call
      IDUP_End_Unprotect()
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         R_Services.Unprot_Service_1.General_Service_Data.minor_status,
      (as required) for more detailed information.

   Utilize
      R_Services.Unprot_Service_1.service_id,
         (to determine which service was applied by the originator; note
          that Unprot_Service_2 will have NULL in unprot_service_type
          to indicate that it is not used)
      R_Services.Unprot_Service_1.Quality,
         (to determine the corresponding quality of the service)
      Prot_Information.originator_name, (from IDUP_Start_Unprotect)
         (to determine the name of the signer)
      major_status (from IDUP_End_Unprotect)
         (to determine pass/fail status of signature verification).

<span class="h3"><a class="selflink" id="appendix-B.4" href="#appendix-B.4">B.4</a>.  More Sophisticated Mechanism, Small Application Buffers</span>

   To illustrate a higher level of complexity, consider the use of a
   more sophisticated IDUP mechanism and a calling application with
   small data buffers.  In particular, consider the case in which a very
   small e-mail message is to be encrypted for a relatively large
   receiver list (R), some subset of whom (r) will be asked to send
   proofs of receipt of the message to some other subset (L) (which
   includes the originator).  So that the example is not unnecessarily
   complicated, assume again that the originating application uses
   encapsulation.

   The uses and defaults for the various parameter bundles for this
   mechanism would be specified in the relevant IDUP mechanism document
   as follows.



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Mech_Specific_Info
      - NOT USED (the only acceptable input, therefore, is NULL)

   Idu_Sensitivity
      - NOT USED (the only acceptable input, therefore, is NULL)

   Service_Creation_Info
      - used to create "proof of delivery" evidence (but actual
        structure is opaque to calling application)

   Service_Verification_Info
      - used to verify "proof of delivery" evidence (but actual
        structure is opaque to calling application)

   Quality
      - the qop_algs parameter must be supported, with a suitable
        DEFAULT value specified;
      - suitable DEFAULT values for validity, policy_id, and
        allow_policy_mapping must be specified (it may be an
        implementation option as to whether these parameters are
        explicitly modifiable by the calling application, or whether
        NULLs are the only acceptable input)

   Idu_Information
      - the idu_type parameter must have a value representing a suitable
        IDU type, with a suitable DEFAULT value specified;
      - the idu_title parameter must have a value representing a
        suitable IDU title, with a suitable DEFAULT value specified

   Prot_Information
      - the originator_name, protection_time, and idu_type / idu_title
        (in Idu_Information) parameters are read from the contained
        header information and output by IDUP_Start_Unprotect;

   Special_Conditions
      - the parameter prot_oper_id is NOT USED (the only acceptable
        input, therefore, is NULL);
      - trusted or untrusted time may be selected by the calling
        application, with a suitable DEFAULT value specified

   Target_Info
      - this bundle is used as described in IDUP; no DEFAULT values are
        specified

   General_Service_Data
      - the unencapsulated_token parameter is used if
        encapsulation_request is FALSE;
      - the minor_status parameter is used to return minor status values



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


        as specified by the mechanism document

   Prot_Service
      - the prot_service_type parameter may have a value of "1"
        ("perform unsolicited service"), "2" ("perform solicited
        service"), "3" (perform service solicitation), or NULL (which
        specifies the DEFAULT value of "1");
      - the service_id parameter must have a value representing
        "PER_CONF", "PER_DOA", "PER_POO", or "PER_POD";
      - the parameters Service_Creation_Info, service_to,
        Service_Verification_Info, and service_verification_info_id are
        used when required by the IDUP operation

   Unprot_Service
      - the unprot_service_type parameter may have a value of "1"
        ("receive unsolicited service"), "2" ("receive solicited
        service"), or "3" (receive service solicitation);
      - the service_id parameter will have a value representing
        "REC_CONF", "REC_DOA", "REC_POO", or "REC_POD";
      - the parameters service_verification_info_id,
        Service_Verification_Info, service_to, and
        Service_Creation_Info, are used when required by the IDUP
        operation


   SENDER (any parameters not listed below are given the value NULL):

   Set
      env_handle                          = environment handle in use;
      Idu_Information.idu_type            = value for "e-mail document";
      Idu_Information.idu_title           = "Contract 1234";
      Special_Conditions.use_trusted_time = TRUE;
      encapsulation_request               = TRUE;
      single_idu_buffer                   = very small e-mail message;
      Target_Info.targ_names              = receiver names (R);
      Prot_Service_1.prot_service_type    = "1";
      Prot_Service_1.service_id           = PER_CONF;
      Prot_Service_2.prot_service_type    = "3";
      Prot_Service_2.service_id           = PER_POD;
      Prot_Service_2.General_Service_Data.Target_Info.targ_names
                                          = "receipts from" list (r);
      Prot_Service_2.service_to           = "receipts to" list (L);
      P_Services.Prot_Service_1           = Prot_Service_1;
      P_Services.Prot_Service_2           = Prot_Service_2;

   Call
      IDUP_Start_Protect() with above input parameters




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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Check
      major_status.  If not GSS_S_COMPLETE,
         while major_status == IDUP_S_MORE_OUTBUFFER_NEEDED
            Save
               pidu_buffer,
            Call
               IDUP_Start_Protect() (to get next portion of pidu_buffer)
         Check
            major_status,
            minor_status,
            Target_Info.bad_targ_names / Target_Info.bad_targ_status,
            P_Services.Prot_Service_1.General_Service_Data.minor_status,
            P_Services.Prot_Service_2.General_Service_Data.minor_status
         (as required) for more detailed information.

   Save
      Prot_Service_2.Service_Verification_Info,
      Prot_Service_2.service_verification_info_id

   Send
      All saved buffers of pidu_buffer to receiver list (R).


   RECEIVER (ON RECEIVER LIST (R)):
      (any parameters not listed below are given the value NULL)

   Set
      env_handle          = environment handle in use;
      partial_pidu_buffer = initial buffer of received p-idu;

   Call
      IDUP_Start_Unprotect() with above input parameters
   While major_status == IDUP_S_MORE_PIDU_NEEDED,
      Set
         partial_pidu_buffer = next buffer of p-idu
      Call
         IDUP_Start_Unprotect()
   Check
      major_status,
      minor_status,
      R_Services.Unprot_Service_1.General_Service_Data.minor_status,
      R_Services.Unprot_Service_2.General_Service_Data.minor_status,
   (as required) for more detailed information

   Save
      initial_idu_buffer (if non-empty)





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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


   Set
      input_buffer = remaining p-idu buffer
   Call
      IDUP_Unprotect() with above input parameter
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status
   Save
      output_buffer

   Call
      IDUP_End_Unprotect()
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         R_Services.Unprot_Service_1.General_Service_Data.minor_status,
         R_Services.Unprot_Service_2.General_Service_Data.minor_status,
      (as required) for more detailed information.

   Utilize
      R_Services.Unprot_Service_1/2.service_id,
         (to determine which services were applied by the originator)
      R_Services.Unprot_Service_1/2.Quality,
         (to determine the corresponding qualities of the service)
      Prot_Information.originator_name/protection_time and
         Prot_Information.Idu_Information.idu_type/idu_title,
         (from IDUP_Start_Unprotect) (to determine originator info.)
      R_Services.Unprot_Service_2.General_Service_Data.Target_Info.
         targ.names, (to determine if rec. is in "receipts from" (r))
      Service_Verification_Info/service_verification_info_id
         (to determine if receiver is in "receipts to" list (L))

   If receiver is in "receipts from" list (r)
      Save
         R_Services.Unprot_Service_2.service_to,
         R_Services.Unprot_Service_2.Service_Creation_Info

   If receiver is in "receipts to" list (L)
      Save
         Service_Verification_Info,
         service_verification_info_id

   RECEIVER (ON "RECEIPTS FROM" LIST (r)):
      (procedure to generate receipt)

   Set
      env_handle                           = environment handle in use;
      Target_Info.targ_names               = service_to



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


      Prot_Service_1.prot_service_type     = "2";
      Prot_Service_1.service_id            = "PER_POD";
      Prot_Service_1.Service_Creation_Info = Service_Creation_Info;
      P_Services.Prot_Service_1            = Prot_Service_1

   Call
      IDUP_Start_Protect() with above input parameters
   Check
      major_status.  If not GSS_S_COMPLETE, check
         minor_status,
         P_Services.Prot_Service_1.General_Service_Data.minor_status
      (as required) for more detailed information.

   Send
      pidu_buffer to "receipts to" list (L)

   RECEIVER (ON "RECEIPTS TO" LIST (L)):
      (procedure to process received receipt)

   Set
      env_handle         = environment handle in use;
      single_pidu_buffer = received p-idu buffer (if it fits in a single
         buffer; otherwise use partial_pidu_buffer and make multiple
         calls, as above)

   Call
      IDUP_Start_Unprotect() with above input parameters
   If major_status == IDUP_S_SERV_VERIF_INFO_NEEDED
      Utilize
         R_Services.Unprot_Service_1.service_verification_info.id
         (to assist in locating necessary Service_Verification_Info)
      Set
         R_Services.Unprot_Service_1.Service_Verification_Info
            = Service_Verification_Info
      Call
         IDUP_Start_Unprotect() with above input parameters
   Check
      major_status,
      minor_status,
      R_Services.Unprot_Service_1.General_Service_Data.minor_status
   (as required) for more detailed information.

   Utilize
      R_Services.Unprot_Service_1.service_id,
         (to determine that this is a "proof of delivery" evidence)
      R_Services.Unprot_Service_1.Quality,
      Prot_Information.originator_name, (for evidence generator info.)
      major_status (to determine pass/fail status of evi. verif.).



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<span class="grey"><a href="./rfc2479">RFC 2479</a>                      IDUP-GSS-API                 December 1998</span>


Full Copyright Statement

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
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   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
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   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
























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