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Lightweight Directory Access Protocol (LDAP) Authorization Identity Request and Response Controls
draft-weltman-ldapv3-auth-response-09

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 3829.
Authors Rob Weltman , Mark C. Smith , Mark Wahl
Last updated 2020-01-21 (Latest revision 2003-04-24)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Informational
Formats
Stream WG state (None)
Document shepherd (None)
IESG IESG state Became RFC 3829 (Informational)
Action Holders
(None)
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD Ted Hardie
Send notices to <Mark.Wahl@sun.com>
draft-weltman-ldapv3-auth-response-09
INTERNET-DRAFT                                               Rob Weltman 
Intended Category: Informational                              Mark Smith 
                                           Netscape Communications Corp. 
                                                               Mark Wahl 
                                                  Sun Microsystems, Inc. 
                                                              April 2003 
 
    
       LDAP Authorization Identity Request and Response Controls 
               draft-weltman-ldapv3-auth-response-09.txt 
 
 
Status of this Memo 
 
   This document is an Internet-Draft and is in full conformance with 
   all provisions of Section 10 of RFC2026. 
    
   Internet-Drafts are working documents of the Internet Task Force 
   (IETF), its areas, and its working groups.  Note that other groups 
   may also distribute working documents as Internet-Drafts. 
    
   Internet-Drafts are draft documents valid for a maximum of six months 
   and may be updated, replaced, or obsoleted by other documents at any 
   time.  It is inappropriate to use Internet Drafts as reference 
   material or to cite them other than as "work in progress." 
    
   The list of current Internet-Drafts can be accessed at 
   http://www.ietf.org/ietf/1id-abstracts.txt. 
    
   The list of Internet-Draft Shadow Directories can be accessed at 
   http://www.ietf.org/shadow.html. 
    
    
Abstract 
    
   This document extends the Lightweight Directory Access Protocol 
   (LDAP) [RFC3377] bind [LDAPPROT] operation with a mechanism for 
   requesting and returning the authorization identity it establishes. 
   Specifically, this document defines the Authorization Identity 
   Request and Response controls for use with the Bind operation. 
    
    
1. Introduction 
    
   This document defines support for the Authorization Identity Request 
   Control and the Authorization Identity Response Control for 
   requesting and returning the authorization established in a bind 
   operation. The Authorization Identity Request Control may be 
   submitted by a client in a bind request if authenticating with 
   version 3 of the Lightweight Directory Access Protocol (LDAP) 
   protocol [LDAPv3]. In the LDAP server's bind response, it may then 
   include an Authorization Identity Response Control. The response 
   control contains the identity assumed by the client. This is useful 
   when there is a mapping step or other indirection during the bind, so 
  
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   that the client can be told what LDAP identity was granted. Client 
   authentication with certificates is the primary situation where this 
   applies. Also, some Simple Authentication and Security Layer (SASL) 
   authentication mechanisms may not involve the client explicitly 
   providing a DN, or may result in an authorization identity which is 
   different from the authentication identity provided by the client 
   [AUTH]. 
    
   The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY" 
   used in this document are to be interpreted as described in 
   [RFCKeyWords]. 
    
    
2. Publishing support for the Authorization Identity Request Control 
   and the Authorization Identity Response Control 
    
   Support for the Authorization Identity Request Control and the 
   Authorization Identity Response Control is indicated by the presence 
   of the Object Identifiers (OIDs) 2.16.840.1.113730.3.4.16 and 
   2.16.840.1.113730.3.4.15, respectively, in the supportedControl 
   attribute [LDAPATTRS] of a server's root DSE. 
    
    
3. Authorization Identity Request Control 
    
    
   This control MAY be included in any bind request which specifies 
   protocol version 3, as part of the controls field of the LDAPMessage 
   as defined in [LDAPPROT]. In a multi-step bind operation, the client 
   MUST provide the control with each bind request. 
    
   The controlType is "2.16.840.1.113730.3.4.16" and the controlValue is 
   absent. 
    
    
4. Authorization Identity Response Control 
    
   This control MAY be included in any final bind response where the 
   first bind request of the bind operation included an Authorization 
   Identity Request Control as part of the controls field of the 
   LDAPMessage as defined in [LDAPPROT]. 
    
   The controlType is "2.16.840.1.113730.3.4.15". If the bind request   
   succeeded and resulted in an identity (not anonymous), the 
   controlValue contains the authorization identity (authzId), as 
   defined in [AUTH] section 9, granted to the requestor. If the bind 
   request resulted in an anonymous association, the controlValue field 
   is a string of zero length. If the bind request resulted in more than 
   one authzId, the primary authzId is returned in the controlValue 
   field. 
    
   The control is only included in a bind response if the resultCode for 
   the bind operation is success. 
  
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   If the server requires confidentiality protections to be in place 
   prior to use of this control (see Security Considerations), the 
   server reports failure to have adequate confidentiality protections 
   in place by returning the confidentialityRequired result code. 
    
   If the client has insufficient access rights to the requested 
   authorization information, the server reports this by returning the 
   insufficientAccessRights result code. 
    
   Identities presented by a client as part of the authentication 
   process may be mapped by the server to one or more authorization 
   identities. The bind response control can be used to retrieve the 
   primary authzId. 
    
   For example, during client authentication with certificates [AUTH], a 
   client may possess more than one certificate and not be able to 
   determine which one was ultimately selected for authentication to the 
   server. The subject DN field in the selected certificate may not 
   correspond exactly to a DN in the directory, but rather have gone 
   through a mapping process controlled by the server. On completing the 
   certificate-based authentication, the client may issue a SASL [SASL] 
   bind request, specifying the EXTERNAL mechanism and including an 
   Authorization Identity Request Control. The bind response MAY include 
   an Authorization Identity Response Control indicating the DN in the 
   server's DIT which the certificate was mapped to. 
    
    
5. Alternative Approach with Extended Operation 
    
   The LDAP "Who am I?" [AUTHZID] extended operation provides a 
   mechanism to query the authorization identity associated with a bound 
   connection. Using an extended operation as opposed to a bind response 
   control allows a client to learn the authorization identity after the 
   bind has has established integrity and data confidentiality 
   protections. The disadvantages of the extended operation approach are 
   coordination issues between "Who am I?" requests, bind requests, and 
   other requests, and that an extra operation is required to learn the 
   authorization identity. For multithreaded or high bandwidth server 
   application environments, the bind response approach may be 
   preferable. 
    
6. Security Considerations 
    
   The Authorization Identity Request and Response Controls are subject 
   to standard LDAP security considerations. The controls may be passed 
   over a secure as well as over an insecure channel. They are not 
   protected by security layers negotiated by the bind operation. 
    
   The response control allows for an additional authorization identity 
   to be passed. In some deployments, these identities may contain 
   confidential information which require privacy protection. In such 

  
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   deployments, a security layer should be established prior to issuing 
   a bind request with an Authorization Identity Request Control. 
    
    
7. IANA Considerations 
    
   The OIDs 2.16.840.1.113730.3.4.16 and 2.16.840.1.113730.3.4.15 are 
   reserved for the Authorization Identity Request and Response 
   Controls, respectively. The Authorization Identity Request Control is 
   to be registered as an LDAP Protocol Mechanism [IANALDAP]. 
    
    
8. Copyright 
    
   Copyright (C) The Internet Society (2003). 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 
   Internet organizations, except as needed for the  purpose of 
   developing Internet standards in which case the procedures for 
   copyrights defined in the Internet Standards process must be 
   followed, or as required to translate it into languages other than 
   English. 
    
   The limited permissions granted above are perpetual and will not be 
   revoked by the Internet Society or its successors or assigns. 
    
   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. 
    
    
9. References 
    
   [LDAPV3] Hodges, J. and R. Morgan, "Lightweight Directory Access 
        Protocol (v3): Technical Specification", RFC 3377, September 
        2002. 
     
   [LDAPPROT] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access 
        Protocol (v3)", RFC 2251, December 1997. 
    
   [RFCKeyWords] Bradner, Scott, "Key Words for use in RFCs to Indicate 
        Requirement Levels", draft-bradner-key-words-03.txt, January 
        1997. 
  
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   [AUTH] M. Wahl, H. Alvestrand, J. Hodges, RL "Bob" Morgan, 
        "Authentication Methods for LDAP", RFC 2829, May 2000. 
    
   [SASL] J. Myers, "Simple Authentication and Security Layer (SASL", 
        RFC 2222, October 1997. 
    
   [AUTHZID] K. Zeilenga, "LDAP 'Who am I?' Operation", draft-zeilenga-
        ldap-authzid-03.txt, April 2002 
    
   [LDAPATTRS] M. Wahl, A. Coulbeck, T. Howes, S. Kille, "Lightweight 
        Directory Access Protocol (v3): Attribute Syntax Definitions", 
        RFC 2252, December 1997 
    
   [IANALDAP] J. Hodges, R. Morgan, "Lightweight Directory Access 
        Protocol (v3): Technical Specification", RFC 3377, September 
        2002 
    
    
    
10. Author's Addresses 
    
   Rob Weltman 
   Netscape Communications Corp. 
   360 W. Caribbean Drive 
   Sunnyvale, CA 94089 
   USA 
   +1 650 937-3194 
   rweltman@netscape.com 
    
   Mark Smith 
   Netscape Communications Corp. 
   360 W. Caribbean Drive 
   Sunnyvale, CA 94089 
   USA 
   +1 650 937-3477 
   mcs@netscape.com 
    
   Mark Wahl 
   Sun Microsystems, Inc. 
   911 Capital of Texas Hwy, Suite 4140 
   Austin, TX 78759  
   USA 
   +1 512 231 7224 
   Mark.Wahl@sun.com 
    
 

  
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