Network Working Group K. Zeilenga
Request for Comments: 3494 OpenLDAP Foundation
Obsoletes: 1484, 1485, 1487, 1488, 1777, March 2003
1778, 1779, 1781, 2559
Category: Informational
Lightweight Directory Access Protocol version 2 (LDAPv2)
to Historic Status
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 (2003). All Rights Reserved.
Abstract
This document recommends the retirement of version 2 of the
Lightweight Directory Access Protocol (LDAPv2) and other dependent
specifications, and discusses the reasons for doing so. This
document recommends RFC 1777, 1778, 1779, 1781, and 2559 (as well as
documents they superseded) be moved to Historic status.
Lightweight Directory Access Protocol, version 2
LDAPv2 (Lightweight Directory Access Protocol, version 2)
[RFC1777][RFC1778][RFC1779] is an Internet Protocol used to access
X.500-based directory services. This document recommends that LDAPv2
and other dependent specifications be retired. Specifically, this
document recommends RFC 1777, 1778, 1779, 1781, and 2559 (as well as
documents they superseded) be moved to Historic status. The reasons
for taking this action are discussed below.
LDAPv2 was published in 1995 as a Draft Standard. Since its
publication, a number of inadequacies in the specification have been
discovered. LDAPv3 [RFC3377] was published in 1997 as a Proposed
Standard to resolve these inadequacies. While LDAPv3 is currently
being revised [LDAPbis], it is clearly technically superior to
LDAPv2.
The LDAPv2 specification is not generally adhered to; that is, an
independently developed implementation of the specification would not
interoperate with existing implementations, as existing
Zeilenga Informational [Page 1]RFC 3494 LDAPv2 to Historic Status March 2003
implementations use syntaxes and semantics different than those
prescribed by the specification. Below are two examples.
1) Existing LDAPv2 implementations do not commonly restrict
textual values to IA5 (ASCII) and T.61 (Teletex) as required by
RFC 1777 and RFC 1778. Some existing implementations use ISO
8859-1, others use UCS-2, others use UTF-8, and some use the
current local character set.
2) RFC 1777 requires use of the textual string associated with
AttributeType in the X.500 Directory standards. However,
existing implementations use the NAME associated with the
AttributeType in the LDAPv3 schema [RFC2252]. That is, LDAPv2
requires the organization name attribute be named
"organizationName", not "o".
In addition, LDAPv2 does not provide adequate security features for
use on the Internet. LDAPv2 does not provide any mechanism for data
integrity or confidentiality. LDAPv2 does not support modern
authentication mechanisms such as those based on DIGEST-MD5, Kerberos
V, and X.509 public keys.
Dependent Specifications
Since the publication of RFC 1777, 1778, and 1779, there have been
additional standard track RFCs published that are dependent on these
technical specifications, including:
"Using the OSI Directory to Achieve User Friendly Naming"
[RFC1781]
and
"Internet X.509 Public Key Infrastructure Operational Protocols -
LDAPv2" [RFC2559].
RFC 1781 is a technical specification for "User Friendly Naming"
which replies on particular syntaxes described in RFC 1779. RFC
2253, which replaced RFC 1779, eliminated support for the "User
Friendly Naming" syntaxes. RFC 1781 is currently a Proposed
Standard.
RFC 2559 is primarily an applicability statement for using LDAPv2 in
providing Public Key Infrastructure. It depends on RFC 1777 and
updates RFC 1778. If LDAPv2 is moved to Historic status, so must
this document. RFC 2559 is currently a Proposed Standard.
Zeilenga Informational [Page 2]RFC 3494 LDAPv2 to Historic Status March 2003
Security Considerations
LDAPv2 does not provide adequate security mechanisms for general use
on the Internet. LDAPv3 offers far superior security mechanisms,
including support for strong authentication and data confidentiality
services. Moving LDAPv2 to Historic may improve the security of the
Internet by encouraging implementation and use of LDAPv3.
Recommendations
Developers should not implement LDAPv2 per RFC 1777, as such would
result in an implementation that will not interoperate with existing
LDAPv2 implementations. Developers should implement LDAPv3 instead.
Deployers should recognize that significant interoperability issues
exist between current LDAPv2 implementations. LDAPv3 is clearly
technically superior to LDAPv2 and hence should be used instead.
It is recommended that RFC 1777, RFC 1778, RFC 1779, RFC 1781, and
RFC 2559 be moved to Historic status.
The previously superseded specifications RFC 1484, 1485, 1487, and
1488 (by RFC 1781, 1779, 1777, and 1778, respectively) should also be
moved to Historic status.
Acknowledgment
The author would like to thank the designers of LDAPv2 for their
contribution to the Internet community.
Normative References
[RFC1777] Yeong, W., Howes, T. and S. Kille, "Lightweight Directory
Access Protocol", RFC 1777, March 1995.
[RFC1778] Howes, T., Kille, S., Yeong, W. and C. Robbins, "The String
Representation of Standard Attribute Syntaxes", RFC 1778,
March 1995.
[RFC1779] Kille, S., "A String Representation of Distinguished
Names", RFC 1779, March 1995.
[RFC1781] Kille, S., "Using the OSI Directory to Achieve User
Friendly Naming", RFC 1781, March 1995.
[RFC2559] Boeyen, S., Howes, T. and P. Richard, "Internet X.509
Public Key Infrastructure Operational Protocols - LDAPv2",
RFC 2559, April 1999.
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Informative References
[LDAPbis] IETF LDAP Revision (v3) Working Group (LDAPbis),
<http://www.ietf.org/html-charters/ldapbis-charter.html>.
[RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access
Protocol (v3): Technical Specification", RFC 3377,
September 2002.
[RFC2252] Wahl, M., Coulbeck, A., Howes, T. and S. Kille,
"Lightweight Directory Access Protocol (v3): Attribute
Syntax Definitions", RFC 2252, December 1997.
[RFC2253] Wahl, M., Kille, S. and T. Howes, "Lightweight Directory
Access Protocol (v3): UTF-8 String Representation of
Distinguished Names", RFC 2253, December 1997.
Author's Address
Kurt D. Zeilenga
OpenLDAP Foundation
EMail: Kurt@OpenLDAP.org
Zeilenga Informational [Page 4]RFC 3494 LDAPv2 to Historic Status March 2003
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