INTERNET-DRAFT                                      Kurt D. Zeilenga
Intended Category: Standard Track                   OpenLDAP Foundation
Expires: 13 December 2000                           13 June 2000


                 LDAP Password Modify Extended Operation
                 <draft-zeilenga-ldap-passwd-exop-03.txt>


1.      Status of this Memo

  This document is an Internet-Draft and is in full conformance with all
  provisions of Section 10 of RFC2026.

  This document is intended to be, after appropriate review and
  revision, submitted to the RFC Editor as a Standard Track document.
  Distribution of this memo is unlimited.  Technical discussion of this
  document will take place on the IETF LDAP Extension Working Group
  mailing list <ietf-ldapext@netscape.com>.  Please send editorial
  comments directly to the author <Kurt@OpenLDAP.org>.

  Internet-Drafts are working documents of the Internet Engineering Task
  Force (IETF), its areas, and its working groups.  Note that other
  groups may also distribute working documents as Internet-Drafts.
  Internet-Drafts are draft documents valid for a maximum of six months
  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.

  Copyright 2000, The Internet Society.  All Rights Reserved.

  Please see the Copyright section near the end of this document for
  more information.


2.      Abstract

  The integration of LDAP [RFC2251] and external authentication services
  has introduced non-DN authentication identities and allowed for
  non-directory storage of passwords.   As such, mechanisms which update
  the directory, such as Modify operation, cannot be used to change a
  user's password.  This document describes an LDAP extended operation
  to allow allow modification of user passwords which is not dependent
  upon the form of the authentication identity nor the password storage



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  mechanism used.

  The key words ``MUST'', ``MUST NOT'', ``REQUIRED'', ``SHALL'', ``SHALL
  NOT'', ``SHOULD'', ``SHOULD NOT'', ``RECOMMENDED'',  and ``MAY'' in
  this document are to be interpreted as described in RFC 2119
  [RFC2119].


3.      Background and Intent of Use

  Lightweight Directory Access Protocol (LDAP) [RFC2251] is designed to
  support an number of authentication mechanisms including simple user
  name/password pairs.  Traditionally LDAP users where identified by the
  Distinguished Name [RFC2253] of a directory entry and this entry
  contained a userPassword [RFC2256] attribute containing one or more
  passwords.

  The protocol does not mandate that passwords associated with a user be
  stored in the directory server.  The server may use any attribute
  suitable for password storage, such as userPassword or authPassword
  [AuthPasswd], or use non-directory storage.

  The integration of application neutral SASL [RFC2222] services which
  support simple username/password mechanisms (such as DIGEST-MD5) has
  introduced non-LDAP DN authentication identity forms and made storage
  of passwords the responsibility of the SASL service provider.

  LDAP update operations are designed to act upon attributes of an entry
  within the directory.  LDAP update operations cannot be used to modify
  a user's password when the user is not represented by a DN, does not
  have a entry, or when that password used by the server is not stored
  as an attribute of an entry.  An alternative mechanism are needed.

  This document describes an LDAP Extended Operation intended to be
  allow directory clients to update user passwords.  The user may or may
  not have be associated with a directory entry. The user may or may not
  be represented as an LDAP DN.  The user's password may or may not be
  stored in the directory.

  The operation SHOULD NOT be used without adequate security protection
  as the operation affords no privacy or integrity protect itself.  This
  operation SHOULD NOT be used by "anonymous" clients.


4.      Password Modify Request and Response

  The Password Modify operation is an LDAPv3 Extended Operation
  [RFC2251, Section 4.12] and is identified by the OBJECT IDENTIFIER



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  passwdModifyOID.  This section details the syntax of the protocol
  request and response.

    passwdModifyOID OBJECT IDENTIFIER ::= 1.3.6.1.4.1.4203.666.6.1

    [Editor's Note: this OID is temporary.  A permanent OID
      will be assigned to this object before this document is
      progressed as an RFC.]

    PasswdModifyRequestValue ::= SEQUENCE {
      userIdentity    [0]  OCTET STRING OPTIONAL
      oldPasswd       [1]  OCTET STRING OPTIONAL
      newPasswd       [2]  OCTET STRING OPTIONAL }

    PasswordModifyResponseValue ::= SEQUENCE {
      genPasswd       [0]     OCTET STRING OPTIONAL }


4.1.    Password Modify Request

  A Password Modify request is an ExtendedRequest with the requestName
  field containing passwdModifyOID OID and optionally provides a
  requestValue field.  If the requestValue field is provided, it SHALL
  contain a PasswdModifyRequestValue with one or more fields present.

  The userIdentity field, if present, SHALL contain an octet string
  representation of the user associated with the request.  This string
  may or may not be an LDAPDN [RFC2253].  If no userIdentity field is
  present, the request acts up upon the password of the user currently
  associated with the LDAP session.

  The oldPasswd field, if present, SHALL contain the user's current
  password.

  The newPasswd field, if present, SHALL contain the desired password
  for this user.


4.2.    Password Modify Response

  A Password Modify response is an ExtendedResponse where the
  responseName field is absent and the response field is optional.  The
  response field, if present, SHALL contain a PasswdModifyResponseValue
  with genPasswd field present.

  The genPasswd field, if present, SHALL contain a generated password
  for the user.




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  If an resultCode other than success (0) is indicated in the response,
  the response field MUST be absent.


5.      Operation Requirements

  Clients SHOULD NOT submit a Password Modification request without
  ensuring adequate security safeguards are in place.  Servers SHOULD
  return a non-success resultCode if sufficient security protection are
  not in place.

  Servers SHOULD indicate their support for this extended operation by
  providing PasswordModifyOID as a value of the supportedExtensions
  attribute type in their root DSE.  Clients SHOULD verify the server
  implements this extended operation prior to attempting the operation
  by asserting the supportedExtensions attribute contains a value of
  PasswordModifyOID.

  The server SHALL only return success upon successfully changing the
  user's password.  The server SHALL leave the password unmodified and
  return a non-success resultCode otherwise.

  If the server does not recognize provided fields or does not support
  the combination of fields provided, it SHALL NOT change the user
  password.

  If the provided oldPasswd value cannot be verified or is incorrect,
  the server SHALL NOT change the user password.

  The server SHALL NOT generate a password on behalf of the client if
  the client has provided a newPassword.  In absence of a client
  provided newPassword, the server SHALL either generate a password on
  behalf of the client or return a non-success result code.  The server
  MUST provide the generated password upon success as the value of the
  genPasswd field.

  The server MAY return adminLimitExceeded, busy,
  confidentialityRequired, operationsError, unavailable,
  unwillingToPerform, or other non-success resultCode as appropriate to
  indicate that it was unable to successfully complete the operation.

  Servers MAY implement administrative policies which restrict this
  operation.


6.      Other requirements

  A server which supports this operation SHOULD provide a



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  supportedExtension attribute in the Root DSE which contains as one of
  its values the passwdModifyOID OID.  A server MAY advertise the
  extension only when the client is authorized and/or has established
  the necessary security protections to use this operation.  Clients
  SHOULD verify the server has advertised the extension before
  attempting the operation.


7.      Security Considerations

  This operation is used to modify user passwords.  The operation itself
  does not provide any security protection to ensure integrity and/or
  confidentiality of the information.  Use of this operation is strongly
  discouraged when privacy protections are not in place to guarantee
  confidentiality and may result in the disclosure of the password to
  unauthorized parties.


8.      Copyright

  Copyright 2000, The Internet Society.  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 AUTHORS, 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.      Bibliography




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  [RFC2219]       S. Bradner, "Key words for use in RFCs to Indicate
                  Requirement Levels", RFC 2119, March 1997.

  [RFC2222]       J. Myers, "Simple Authentication and Security
                  Layer (SASL)", RFC 2222, October 1997.

  [RFC2251]       M. Wahl, T. Howes, S. Kille, "Lightweight
                  Directory Access Protocol (v3)", RFC 2251,
                  December 1997.

  [RFC2252]       M. Wahl, A. Coulbeck, T. Howes, S. Kille,
                  "Lightweight Directory Access Protocol (v3):
                  Attribute Syntax Definitions", RFC 2252,
                  December 1997.

  [RFC2253]       M. Wahl, S. Kille, T. Howes, "Lightweight
                  Directory Access Protocol (v3): UTF-8 String
                  Representation of Distinguished Names", RFC 2253,
                  December 1997.

  [RFC2256]       M. Wahl, "A Summary of the X.500(96) User Schema
                  for use with LDAPv3", RFC 2256, December 1997.

  [AuthPasswd]    K. Zeilenga, "LDAP Authentication Password
                  Attribute", draft-zeilenga-ldap-authpasswd-xx.txt,
                  a work in progress.

10.     Acknowledgment

  This document borrows from a number of IETF documents and is based
  upon input from the IETF LDAPext working group.


11.     Author's Address

  Kurt D. Zeilenga
  OpenLDAP Foundation
  <Kurt@OpenLDAP.org>













Zeilenga                                                        [Page 6]

