Network Working Group Rob Weltman
INTERNET-DRAFT Netscape Communications Corp.
Mark Smith
Netscape Communications Corp.
February, 2000
LDAP Authentication Response Control
draft-weltman-ldapv3-auth-response-01.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 defines support for the Authentication Response
Control. Controls are an LDAP protocol version 3 extension, to allow
passing arbitrary control information along with a standard request
to a server, and to receive arbitrary information back with a
standard result. The Authentication Response Control may be returned
by an LDAP server in a bind response to a client authenticating with
version 3 of the LDAP protocol. The control contains the identity
assumed by the client. This is useful when there is a mapping step or
other indirection during the bind, so that the client can be told
what LDAP identity was granted. Client authentication with
certificates is the primary situation where this applies. Also, some
SASL authentication mechanisms may not involve the client explicitly
providing a DN.
1. Introduction
Version 3 of the LDAP protocol provides a means of supplying
arbitrary additional information along with a request to an LDAP
server, and receiving arbitrary additional response information. The
Expires August 2000 [Page 1]
AUTHENTICATION RESPONSE CONTROL February, 2000
Control protocol extension is described in [LDAPv3], section 4.1.12.
This document defines a way for a server to return the identity
assumed by a client on binding using the Control mechanism.
The key words "MUST", "SHOULD", and "MAY" used in this document are
to be interpreted as described in [RFCKeyWords].
2. Publishing support for the Authentication Response Control
Support for the Authentication Response Control is indicated by the
presence of the OID "TBD" in the supportedExtensions attribute of a
server's root DSE.
3. Authentication Response Control
This control may be included in any final bind response where the
bind request specified protocol version 3, as part of the controls
field of the LDAPMessage as defined in [LDAPv3]. The control is not
solicited by the client.
AuthResponseControl ::= SEQUENCE {
controlType TBD,
criticality BOOLEAN DEFAULT FALSE,
controlValue AuthResponseValue
}
The criticality field is not used. The controlValue contains the DN
of the identity established during the bind request, and the
mechanism used to authenticate:
AuthResponseValue::= SEQUENCE {
authDN LDAPDN
authMechanism OCTET STRING
}
If the bind request failed, the authDN and authMechanism values have
zero length. Also, if the bind request resulted in anonymous
authentication, the authDN and authMechanism values have zero length.
If SASL was used for authentication, the value MUST be "SASL/"
followed by the IANA-registered SASL mechanism which was used, for
example:
SASL/DIGEST-MD5
For simple authentication, the value of authMechanism MUST be:
simple
During client authentication with certificates [AUTH], a client may
possess more than one certificate and not be able to determine which
Expires August 2000 [Page 2
AUTHENTICATION RESPONSE CONTROL February, 2000
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. The bind response
may include an authentication response control indicating the DN in
the server's DIT which the certificate was mapped to.
4. Security Considerations
The Authentication Response Control is subject to standard LDAP
security considerations. The control may be passed over a secure as
well as over an insecure channel. No additional confidential
information is passed in the control.
5. Copyright
Copyright (C) The Internet Society (1999). 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.
6. Bibliography
[LDAPv3] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access
Protocol (v3)", Internet Draft draft-ietf-asid-ldapv3-protocol-
06.txt, July 1997.
Expires August 2000 [Page 3
AUTHENTICATION RESPONSE CONTROL February, 2000
[RFCKeyWords] Bradner, Scott, "Key Words for use in RFCs to Indicate
Requirement Levels", draft-bradner-key-words-03.txt, January,
1997.
[AUTH] M. Wahl, H. Alvestrand, J. Hodges, RL "Bob" Morgan,
"Authentication Methods for LDAP", draft-ietf-ldapext-authmeth-
04.txt, June, 1999.
[SASL] J. Myers, "Simple Authentication and Security Layer (SASL",
RFC 2222, October, 1997.
[ASN.1] X.680 : ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-
1:1998, Information Technology - Abstract Syntax Notation One
(ASN.1): Specification of Basic Notation
7. Author's Addresses
Rob Weltman
Netscape Communications Corp.
MV-068
501 E. Middlefield Rd.
Mountain View, CA 94043
USA
+1 650 937-3301
rweltman@netscape.com
Mark Smith
Netscape Communications Corp.
MV-068
501 E. Middlefield Rd.
Mountain View, CA 94043
USA
+1 650 937-3477
mcs@netscape.com
8. Changes from draft-weltman-ldapv3-auth-response-00.txt
8.1 Capitalization of ASN.1 macros
AuthResponseControl and AuthResponseValue are capitalized.
8.2 Clarifications
Added sentence on behavior for anonymous binds.
Expires August 2000 [Page 4
