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
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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>
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