Lightweight Directory Access Protocol (LDAP) "Who am I?" Operation
The information below is for an old version of the document that is already published as an RFC.
This is an older version of an Internet-Draft that was ultimately published as RFC 4532.
|Last updated||2020-01-21 (Latest revision 2004-11-19)|
|RFC stream||Internet Engineering Task Force (IETF)|
|IESG||IESG state||RFC 4532 (Proposed Standard)|
|Responsible AD||Ted Hardie|
|Send notices to||(None)|
INTERNET-DRAFT Kurt D. Zeilenga Intended Category: Standard Track OpenLDAP Foundation Expires in six months 19 November 2004 LDAP "Who am I?" Operation <draft-zeilenga-ldap-authzid-10.txt> Status of this Memo 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 Extensions mailing list <firstname.lastname@example.org>. Please send editorial comments directly to the author <Kurt@OpenLDAP.org>. By submitting this Internet-Draft, I accept the provisions of Section 4 of RFC 3667. By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, or will be disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. 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 (C) The Internet Society (2004). All Rights Reserved. Please see the Full Copyright section near the end of this document for more information. Abstract This specification provides a mechanism for Lightweight Directory Zeilenga LDAP "Who am I?" [Page 1] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 Access Protocol (LDAP) clients to obtain the authorization identity which the server has associated with the user or application entity. This mechanism is specified as an LDAP extended operation called the LDAP "Who am I?" operation. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119]. 1. Background and Intent of Use This specification describes a Lightweight Directory Access Protocol (LDAP) [RFC3377] operation which clients can use to obtain the primary authorization identity in its primary form which the server has associated with the user or application entity. The operation is called the "Who am I?" operation. This specification is intended to replace the existing [AUTHRESP] mechanism which uses Bind request and response controls to request and return the authorization identity. Bind controls are not protected by the security layers established by the Bind operation which includes them. While it is possible to establish security layers using Start TLS [RFC2830] prior to the Bind operation, it is often desirable to use security layers established by the Bind operation. An extended operation sent after a Bind operation is protected by the security layers established by the Bind operation. There are other cases where it is desirable to request the authorization identity which the server associated with the client separately from the Bind operation. For example, the "Who am I?" operation can be augmented with a Proxied Authorization Control [PROXYAUTH] to determine the authorization identity which the server associates with the identity asserted in the Proxied Authorization Control. The "Who am I?" operation can also be used prior to the Bind operation. Servers often associate multiple authorization identities with the client and each authorization identity may be represented by multiple authzId [RFC2829] strings. This operation requests and returns the authzId the server considers to be primary. In the specification, the term "the authorization identity" and "the authzId" are generally to be read as "the primary authorization identity" and the "the primary authzId", respectively. Zeilenga LDAP "Who am I?" [Page 2] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 2. The "Who am I?" Operation The "Who am I?" operation is defined as an LDAP Extended Operation [RFC2251, Section 4.12] identified by the whoamiOID Object Identifier (OID). This section details the syntax of the operation's whoami request and response messages. whoamiOID ::= "220.127.116.11.4.1.418.104.22.168" 2.1. The whoami Request The whoami request is an ExtendedRequest with the requestName field containing the whoamiOID OID and an absent requestValue field. For example, a whoami request could be encoded as the sequence of octets (in hex): 30 1e 02 01 02 77 19 80 17 31 2e 33 2e 36 2e 31 2e 34 2e 31 2e 34 32 30 33 2e 31 2e 31 31 2e 33 2.2. The whoami Response The whoami response is an ExtendedResponse where the responseName field is absent and the response field, if present, is empty or an authzId [RFC2829]. For example, a whoami response returning the authzId "u:xxyyz@EXAMPLE.NET" (in response to the example request) would be encoded as the sequence of octets (in hex): 30 21 02 01 02 78 1c 0a 01 00 04 00 04 00 8b 13 75 3a 78 78 79 79 7a 40 45 58 41 4d 50 4c 45 2e 4e 45 54 3. Operational Semantics The "Who am I?" operation provides a mechanism, a whoami Request, for the client to request that the server returns the authorization identity it currently associates with the client and provides a mechanism, a whoami Response, for the server to respond to that request. Servers indicate their support for this extended operation by providing whoamiOID object identifier as a value of the 'supportedExtension' attribute type in their root DSE. Server SHOULD advertise this extension only when the client is willing and able to perform this operation. Zeilenga LDAP "Who am I?" [Page 3] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 If the server is willing and able to provide the authorization identity it associates with the client, the server SHALL return a whoami Response with a success resultCode. If the server is treating the client as an anonymous entity, the response field is present but empty. Otherwise the server provides the authzId [RFC2829] representing the authorization identity it currently associates with the client in the response field. If the server is unwilling or unable to provide the authorization identity it associates with the client, the server SHALL return a whoami Response with an appropriate non-success resultCode (such as operationsError, protocolError, confidentialityRequired, insufficientAccessRights, busy, unavailable, unwillingToPerform, or other) and an absent response field. As described in [RFC2251] and [RFC2829], an LDAP session has an "anonymous" association until the client has been successfully authenticated using the Bind operation. Clients MUST NOT invoke the "Who Am I?" operation while any Bind operation is in progress, including between two Bind requests made as part of a multi-stage Bind operation. Where a whoami Request is received in violation of this absolute prohibition, the server should return a whoami Response with an operationsError resultCode. 4. Extending the "Who am I?" operation with controls Future specifications may extend the "Who am I?" operation using the control mechanism [RFC2251]. When extended by controls, the "Who am I?" operation requests and returns the authorization identity the server associates with the client in a particular context indicated by the controls. 4.1. Proxied Authorization Control The Proxied Authorization Control [PROXYAUTH] is used by clients to request that the operation it is attached to operates under the authorization of an assumed identity. The client provides the identity to assume in the Proxied Authorization request control. If the client is authorized to assume the requested identity, the server executes the operation as if the requested identity had issued the operation. As servers often map the asserted authzId to another identity [RFC2829], it is desirable to request the server provide the authzId it associates with the assumed identity. Zeilenga LDAP "Who am I?" [Page 4] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 When a Proxied Authorization Control is be attached to the "Who Am I?" operation, the operation requests the return of the authzId the server associates with the identity asserted in the Proxied Authorization Control. The TBD result code is used to indicate that the server does not allow the client to assume the asserted identity. [[Note to RFC Editor: TBD is to be replaced with the name/code assigned by IANA for [PROXYAUTH] use.]] 5. Security Considerations Identities associated with users may be sensitive information. When so, security layers [RFC2829][RFC2830] should be established to protect this information. This mechanism is specifically designed to allow security layers established by a Bind operation to protect the integrity and/or confidentiality of the authorization identity. Servers may place access control or other restrictions upon the use of this operation. As stated in Section 3, the server SHOULD advertise this extension when it is willing and able to perform the operation. As with any other extended operations, general LDAP security considerations [RFC3377] apply. 6. IANA Considerations The OID 22.214.171.124.4.1.4126.96.36.199 is used to identify the LDAP "Who Am I?" extended operation. This OID was assigned [ASSIGN] by OpenLDAP Foundation, under its IANA-assigned private enterprise allocation [PRIVATE], for use in this specification. Registration of this protocol mechanism [RFC3383] is requested. Subject: Request for LDAP Protocol Mechanism Registration Object Identifier: 188.8.131.52.4.1.4184.108.40.206 Description: Who am I? Person & email address to contact for further information: Kurt Zeilenga <email@example.com> Usage: Extended Operation Specification: RFC XXXX Author/Change Controller: IESG Comments: none 7. Acknowledgment This document borrows from prior work in this area including Zeilenga LDAP "Who am I?" [Page 5] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 "Authentication Response Control" [AUTHRESP] by Rob Weltman, Mark Smith and Mark Wahl. The LDAP "Who am I?" operation takes it name from the UNIX whoami(1) command. The whoami(1) command displays the effective user id. 8. Author's Address Kurt D. Zeilenga OpenLDAP Foundation Email: Kurt@OpenLDAP.org 9. References [[Note to the RFC Editor: please replace the citation tags used in referencing Internet-Drafts with tags of the form RFCnnnn where possible.]] 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14 (also RFC 2119), March 1997. [RFC2251] Wahl, M., T. Howes and S. Kille, "Lightweight Directory Access Protocol (v3)", RFC 2251, December 1997. [RFC2829] Wahl, M., H. Alvestrand, and J. Hodges, RL "Bob" Morgan, "Authentication Methods for LDAP", RFC 2829, June 2000. [RFC2830] Hodges, J., R. Morgan, and M. Wahl, "Lightweight Directory Access Protocol (v3): Extension for Transport Layer Security", RFC 2830, May 2000. [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access Protocol (v3): Technical Specification", RFC 3377, September 2002. [PROXYAUTH] Weltman, R., "LDAP Proxy Authentication Control", draft-weltman-ldapv3-proxy-xx.txt, a work in progress. 9.2. Informative References [RFC3383] Zeilenga, K., "IANA Considerations for LDAP", BCP 64 Zeilenga LDAP "Who am I?" [Page 6] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 (also RFC 3383), September 2002. [AUTHRESP] Weltman, R., M. Smith and M. Wahl, "LDAP Authorization Identity Response and Request Controls", draft-weltman-ldapv3-auth-response-xx.txt, a work in progress. [ASSIGN] OpenLDAP Foundation, "OpenLDAP OID Delegations", http://www.openldap.org/foundation/oid-delegate.txt. [PRIVATE] IANA, "Private Enterprise Numbers", http://www.iana.org/assignments/enterprise-numbers. Intellectual Property Rights The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at firstname.lastname@example.org. Full Copyright Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. This document and the information contained herein are provided on an Zeilenga LDAP "Who am I?" [Page 7] INTERNET-DRAFT draft-zeilenga-ldap-authzid-10 19 November 2004 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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. Zeilenga LDAP "Who am I?" [Page 8]