INTERNET-DRAFT Kurt D. Zeilenga Intended Category: Standard Track OpenLDAP Foundation Expires: 13 December 2000 13 June 2000 LDAP Password Modify Extended Operation 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 . Please send editorial comments directly to the author . 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 Zeilenga [Page 1] INTERNET-DRAFT draft-zeilenga-ldap-passwd-exop-03 13 June 2000 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 Zeilenga [Page 2] INTERNET-DRAFT draft-zeilenga-ldap-passwd-exop-03 13 June 2000 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. Zeilenga [Page 3] INTERNET-DRAFT draft-zeilenga-ldap-passwd-exop-03 13 June 2000 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 Zeilenga [Page 4] INTERNET-DRAFT draft-zeilenga-ldap-passwd-exop-03 13 June 2000 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 Zeilenga [Page 5] INTERNET-DRAFT draft-zeilenga-ldap-passwd-exop-03 13 June 2000 [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 Zeilenga [Page 6]