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