From: Kurt Zeilenga Date: Wed, 27 Oct 2004 04:52:02 +0000 (+0000) Subject: Recent updates X-Git-Tag: OPENLDAP_REL_ENG_2_3_0ALPHA~403 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=68a4288abaab91d25e206cf1f02292c7279008da;p=openldap Recent updates --- diff --git a/doc/drafts/draft-ietf-ldapbis-authmeth-xx.txt b/doc/drafts/draft-ietf-ldapbis-authmeth-xx.txt index 35e35e1d22..859fd449d3 100644 --- a/doc/drafts/draft-ietf-ldapbis-authmeth-xx.txt +++ b/doc/drafts/draft-ietf-ldapbis-authmeth-xx.txt @@ -1,8 +1,6 @@ - - INTERNET-DRAFT Editor: R. Harrison -draft-ietf-ldapbis-authmeth-12.txt Novell, Inc. -Obsoletes: 2829, 2830 August, 2004 +draft-ietf-ldapbis-authmeth-13.txt Novell, Inc. +Obsoletes: 2829, 2830 October, 2004 Intended Category: Draft Standard @@ -11,18 +9,22 @@ Intended Category: Draft Standard + LDAP: Authentication Methods and Connection Level Security Mechanisms + Status of this Memo + 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, and any of which I become aware will be disclosed, in accordance with RFC 3668. + 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 @@ -31,52 +33,65 @@ Status of this Memo editorial comments directly to the author . + 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 Notice + Copyright (C) The Internet Society (2004). All Rights Reserved. + Abstract -Harrison Expires February 2005 [Page 1] - -Internet-Draft LDAP Authentication Methods 16 July 2004 + +Harrison Expires April 2005 [Page 1] +Internet-Draft LDAP Authentication Methods 25 October 2004 + This document describes authentication methods and connection level security mechanisms of the Lightweight Directory Access Protocol (LDAP). + This document details establishment of TLS (Transport Layer Security) using the StartTLS operation. + This document details the simple Bind authentication method including anonymous, unauthenticated, and plain-text password mechanisms and the SASL (Simple Authentication and Security Layer) Bind authentication method including DIGEST-MD5 and EXTERNAL mechanisms. + This document discusses various authentication and authorization states through which a connection to an LDAP server may pass and the actions that trigger these state changes. + Table of Contents + 1. Introduction.....................................................3 1.1. Relationship to Other Documents................................5 1.2. Conventions Used in this Document..............................6 @@ -90,109 +105,125 @@ Table of Contents 3.1.2. StartTLS Response............................................8 3.1.3. TLS Version Negotiation......................................8 3.1.4. Client Certificate...........................................8 - 3.1.5. Discovery of Resultant Security Level........................8 + 3.1.5. Discovery of Resultant Security Level........................9 3.1.6. Server Identity Check........................................9 - 3.1.7. Refresh of Server Capabilities Information...................9 + 3.1.7. Refresh of Server Capabilities Information..................10 3.2. Effects of TLS on a Client's Authorization Identity...........10 3.2.1. TLS Connection Establishment Effects........................10 3.2.2. Client Assertion of Authorization Identity..................10 3.2.3. TLS Connection Closure Effects..............................10 - 3.3. TLS Ciphersuites..............................................10 + 3.3. TLS Ciphersuites..............................................11 3.3.1. TLS Ciphersuites Recommendations............................11 - 4. LDAP Associations...............................................12 - 4.1. Anonymous LDAP Association on Unbound Connections.............12 - 4.2. Anonymous LDAP Association After Failed Bind..................12 + 4. Associations....................................................12 + 4.1. Anonymous Association on Unbound Connections..................12 + 4.2. Anonymous Association After Failed Bind.......................12 4.3. Invalidated Associations......................................12 - 5. Bind Operation..................................................12 + 5. Bind Operation..................................................13 5.1. Simple Authentication Choice..................................13 5.2. SASL Authentication Choice....................................13 6. Anonymous Authentication Mechanism of Simple Bind...............13 7. Unauthenticated Authentication Mechanism of Simple Bind.........13 -Harrison Expires February 2005 [Page 2] - -Internet-Draft LDAP Authentication Methods 16 July 2004 + +Harrison Expires April 2005 [Page 2] +Internet-Draft LDAP Authentication Methods 25 October 2004 + 8. Simple Authentication Mechanism of Simple Bind .................14 - 9. SASL Protocol Profile...........................................14 - 9.1. SASL Service Name for LDAP....................................14 + 9. SASL Protocol Profile...........................................15 + 9.1. SASL Service Name for LDAP....................................15 9.2. SASL Authentication Initiation and Protocol Exchange..........15 9.3. Octet Where Negotiated Security Mechanisms Take Effect........16 9.4. Determination of Supported SASL Mechanisms....................16 - 9.5. Rules for Using SASL Security Layers..........................16 + 9.5. Rules for Using SASL Security Layers..........................17 9.6 Support for Multiple Authentications...........................17 - 10. SASL EXTERNAL Mechanism........................................17 + 10. SASL EXTERNAL Authentication Mechanism.........................17 10.1. Implicit Assertion...........................................17 - 10.2. Explicit Assertion...........................................17 - 10.3. SASL Authorization Identity..................................17 + 10.2. Explicit Assertion...........................................18 + 10.3. SASL Authorization Identity..................................18 10.4. SASL Authorization Identity Syntax...........................18 - 11. SASL DIGEST-MD5 Mechanism......................................19 - 12. Security Considerations........................................20 - 12.1. General LDAP Security Considerations.........................20 - 12.1.1.Password-related Security Considerations....................21 - 12.2. StartTLS Security Considerations.............................22 - 12.3. Unauthenticated Mechanism Security Considerations............22 - 12.4. Simple Mechanism Security Considerations.....................23 - 12.5. SASL DIGEST-MD5 Mechanism Security Considerations............23 - 12.6. Related Security Considerations..............................23 - 13. IANA Considerations............................................23 - Acknowledgments....................................................23 - Normative References...............................................24 - Informative References.............................................25 - Author's Address...................................................25 - Appendix A. LDAP Association State Transition Tables...............25 - A.1. LDAP Association States.......................................25 - A.2. Actions that Affect LDAP Association State....................26 - A.3. Decisions Used in Making LDAP Association State Changes.......26 - A.4. LDAP Association State Transition Table.......................27 - Appendix B. Authentication and Authorization Concepts..............27 - B.1. Access Control Policy.........................................28 - B.2. Access Control Factors........................................28 - B.3. Authentication, Credentials, Identity.........................28 - B.4. Authorization Identity........................................28 - Appendix C. RFC 2829 Change History................................29 - Appendix D. RFC 2830 Change History................................33 - Appendix E. RFC 2251 Change History................................33 - Appendix F. Change History to Combined Document....................33 - Intellectual Property Rights.......................................52 + 11. SASL DIGEST-MD5 Authentication Mechanism.......................19 + 12. Security Considerations........................................19 + 12.1. General LDAP Security Considerations.........................19 + 12.1.1. Password-related Security Considerations...................20 + 12.2. StartTLS Security Considerations.............................20 + 12.3. Unauthenticated Mechanism Security Considerations............21 + 12.4. Simple Mechanism Security Considerations.....................21 + 12.5. SASL DIGEST-MD5 Mechanism Security Considerations............21 + 12.6. Related Security Considerations..............................22 + 13. IANA Considerations............................................22 + Acknowledgments....................................................22 + Normative References...............................................22 + Informative References.............................................23 + Author's Address...................................................24 + Appendix A. Association State Transition Tables....................24 + A.1. Association States............................................24 + A.2. Actions that Affect Association State.........................25 + A.3. Decisions Used in Making Association State Changes............25 + A.4. Association State Transition Table............................25 + Appendix B. Authentication and Authorization Concepts..............26 + B.1. Access Control Policy.........................................26 + B.2. Access Control Factors........................................26 + B.3. Authentication, Credentials, Identity.........................27 + B.4. Authorization Identity........................................27 + Appendix C. RFC 2829 Change History................................27 + Appendix D. RFC 2830 Change History................................31 + Appendix E. RFC 2251 Change History................................32 + Appendix F. Change History to Combined Document....................32 + Added implementation requirement that server implementations ......45 + Intellectual Property Rights.......................................45 + 1. Introduction + The Lightweight Directory Access Protocol (LDAP) [Roadmap] is a powerful protocol for accessing directories. It offers means of + + + + +Harrison Expires April 2005 [Page 3] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + searching, retrieving and manipulating directory content, and ways to access a rich set of security functions. -Harrison Expires February 2005 [Page 3] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - It is vital that these security functions be interoperable among all LDAP clients and servers on the Internet; therefore there has to be a minimum subset of security functions that is common to all implementations that claim LDAP conformance. + Basic threats to an LDAP directory service include: + (1) Unauthorized access to directory data via data-retrieval operations, + (2) Unauthorized access to directory data by monitoring others' access, + (3) Unauthorized access to reusable client authentication information by monitoring others' access, + (4) Unauthorized modification of directory data, + (5) Unauthorized modification of configuration information, + (6) Denial of Service: Use of resources (commonly in excess) in a manner intended to deny service to others, + (7) Spoofing: Tricking a user or client into believing that information came from the directory when in fact it did not, either by modifying data in transit or misdirecting the client's @@ -202,69 +233,84 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 that information came from a particular client when in fact it came from a hostile entity, and + (8) Hijacking: An attacker seizes control of an established protocol session. + Threats (1), (4), (5), (6), (7) are (8) are active attacks. Threats (2) and (3) are passive attacks. + Threats (1), (4), (5) and (6) are due to hostile clients. Threats (2), (3), (7) and (8) are due to hostile agents on the path between client and server or hostile agents posing as a server, e.g. IP spoofing. + LDAP offers the following security mechanisms: + (1) Authentication by means of the Bind operation. The Bind operation provides a simple method which supports anonymous, unauthenticated, and authenticated with password mechanisms, and the Secure Authentication and Security Layer (SASL) method which supports a wide variety of authentication mechanisms, + +Harrison Expires April 2005 [Page 4] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + (2) Mechanisms to support vendor-specific access control facilities (LDAP does not offer a standard access control facility) -Harrison Expires February 2005 [Page 4] - -Internet-Draft LDAP Authentication Methods 16 July 2004 + (3) Data integrity protection by means of security layers in TLS or + SASL mechanisms, - (3) Data integrity protection by means of TLS or SASL mechanisms - with security layers that provide data integrity protection, - (4) Data confidentiality protection by means of the TLS protocol or - SASL mechanisms that provide data confidentiality protection, + (4) Data confidentiality protection by means of security layers in + TLS or SASL mechanisms, + (5) Server resource usage limitation by means of administrative limits configured on the server, and + (6) Server authentication by means of the TLS protocol or SASL mechanism. + LDAP may also be protected by means outside the LDAP protocol, e.g. with IP-level security [RFC2401]. + At the moment, imposition of access controls is done by means outside the scope of LDAP. - It seems clear that allowing implementations, faced with the above - requirements, to simply pick and choose among the possible - alternatives is not a strategy that is likely to lead to - interoperability. In the absence of mandates, clients will be - written that do not support any security function supported by the - server, or worse, they will support only clear text passwords that - provide inadequate security for most circumstances. + + Considering the above requirements, experience has shown that simply + allowing implementations to pick and choose among the possible + alternatives is not a strategy that leads to interoperability. In + the absence of mandates, clients will continue to be written that do + not support any security function supported by the server, or worse, + they will support only clear text passwords that provide inadequate + security for most circumstances. + It is desirable to allow clients to authenticate using a variety of mechanisms including mechanisms where identities are represented as distinguished names [X.501] [Models] in string form [LDAPDN] or are used in different systems (e.g. user name in string form). Because - these authentication mechanisms transmit credentials in plain text - form and other authentication mechanisms do not provide data - security services, it is desirable to ensure secure interopability - by indentifying a mandatory-to-implement mechanism for establishing - transport-layer security services. + some authentication mechanisms transmit credentials in plain text + form and/or do not provide data security services, it is necessary + to ensure secure interoperability by identifying a mandatory-to- + implement mechanism for establishing transport-layer security + services. + The set of security mechanisms provided in LDAP and described in this document is intended to meet the security needs for a wide @@ -274,44 +320,59 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 mechanisms that might be used to achieve a reasonable level of security in various circumstances. + 1.1. Relationship to Other Documents + This document is an integral part of the LDAP Technical Specification [Roadmap]. + This document obsoletes RFC 2829. + +Harrison Expires April 2005 [Page 5] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + Sections 2 and 4 of RFC 2830 are obsoleted by [Protocol]. The remainder of RFC 2830 is obsoleted by this document. -Harrison Expires February 2005 [Page 5] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - 1.2. Conventions Used in this Document + 1.2.1. Glossary of Terms + The following terms are used in this document. To aid the reader, these terms are defined here. + - "user" represents any human or application entity which is accessing the directory using a directory client. A directory client (or client) is also known as a directory user agent (DUA). - - "connection" and "LDAP connection" both refer to the underlying - transport protocol connection between two protocol peers. + + - "connection" refers to the underlying transport protocol + connection used to carry the protocol exchange. + - "TLS connection" refers to an LDAP connection with TLS protection [TLS]. - - "association" and "LDAP association" both refer to the - association of the LDAP connection and its current - authentication and authorization state. + + - "association" refers to the association that exists between the + connection to its current authorization state. As a shorthand, + an association with an authorization state of can be + referred to as a " association", e.g. an association with + an anonymous authorization state is an anonymous association. + 1.2.2. Security Terms and Concepts + In general, security terms in this document are used consistently with the definitions provided in [RFC2828]. In addition, several terms and concepts relating to security, authentication, and @@ -322,148 +383,185 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 unfamiliar with security-related concepts are encouraged to review Appendix C before reading the remainder of this document. + 1.2.3. Keywords + 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 RFC 2119 [RFC2119]. + 2. Implementation Requirements + LDAP server implementations MUST support the anonymous authentication mechanism of simple bind (as discussed in Section 6). + LDAP implementations that support any authentication mechanism other than the anonymous authentication mechanism of simple bind MUST support the DIGEST-MD5 [DIGEST-MD5] mechanism of SASL bind (as detailed in section 11). DIGEST-MD5 is a reasonably strong + + +Harrison Expires April 2005 [Page 6] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + authentication mechanism that provides (mandatory-to-implement) data security (data integrity and data confidentiality) services. + LDAP impementations SHOULD support the simple (DN and password) authentication mechanism of simple bind (as detailed in section 8). - -Harrison Expires February 2005 [Page 6] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Implementations that support this mechanism MUST be capable of protecting it by establishment of TLS (as discussed in section 3) or other suitable suitable data confidentiality and data integrity protection (e.g. IPSec). - Implementations MAY support additional mechanisms of the simple and - SASL bind choices. Some of these mechanisms are discussed below. + + Implementations MAY support additional authentication mechanisms. + Some of these mechanisms are discussed below. + LDAP server implementations SHOULD support client assertion of authorization identity via the SASL EXTERNAL mechanism (sections 3.2.2 and 9). + LDAP server implementations SHOULD support the StartTLS operation, and server implementations that do support the StartTLS operation MUST support the TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA ciphersuite. + 3. StartTLS Operation + The Start Transport Layer Security (StartTLS) operation defined in section 4.14 of [Protocol] provides the ability to establish TLS [TLS] on an LDAP connection. + + The goals of using the TLS [TLS] protocol with LDAP are to ensure + data confidentiality and integrity, and to optionally provide for + authentication. TLS expressly provides these capabilities, although + the authentication services of TLS are available to LDAP only in + combination with the SASL EXTERNAL authentication method (see + section 10), and then only if the SASL EXTERNAL implementation + chooses to make use of the TLS credentials. + + 3.1. Sequencing of the StartTLS Operation + This section describes the overall procedures clients and servers must follow for TLS establishment. These procedures take into - consideration various aspects of the overall security of the LDAP - association including discovery of resultant security level and - assertion of the client's authorization identity. + consideration various aspects of the association including discovery + of resultant security level and assertion of the client's + authorization identity. - Note that the precise effects, on a client's authorization identity, - of establishing TLS on an LDAP connection are described in detail in - section 3.2. 3.1.1. StartTLS Request + A client may send the StartTLS extended request at any time after establishing an LDAP connection, except: + - when TLS is currently established on the connection, - when a multi-stage SASL negotiation is in progress on the connection, or - when it has not yet received responses for all operation requests previously issued on the connection. + + +Harrison Expires April 2005 [Page 7] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + As described in [Protocol] Section 4.14.2.2, a (detected) violation of any of these requirements results in a return of the operationsError resultCode. + Client implementers should ensure that they strictly follow these operation sequencing requirements to prevent interoperability issues. Operational experience has shown that violating these requirements causes interoperability issues because there are race conditions that prevent servers from detecting some violations of - -Harrison Expires February 2005 [Page 7] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - these requirements due to server hardware speed, network latencies, etc. + There is no general requirement that the client have or have not already performed a Bind operation (section 4) before sending a StartTLS operation request. + If the client did not establish a TLS connection before sending a request and the server requires the client to establish a TLS connection before performing that request, the server MUST reject that request by sending a resultCode of confidentialityRequired. + 3.1.2. StartTLS Response + The server will return an extended response with the resultCode of success if it is willing and able to negotiate TLS. + It will return a resultCode other than success (documented in [Protocol] section 4.13.2.2) if it is unwilling or unable to do so. - The client's current association is unaffected if a non-success + The state of the association is unaffected if a non-success resultCode is returned. + In the successful case, the client (which has ceased to transfer LDAP requests on the connection) MUST either begin a TLS negotiation or close the connection. The client will send PDUs in the TLS Record Protocol directly over the underlying transport connection to the server to initiate [TLS] negotiation. + 3.1.3. TLS Version Negotiation + Negotiating the version of TLS to be used is a part of the TLS Handshake Protocol [TLS]. Please refer to that document for details. + 3.1.4. Client Certificate - In an LDAP server requests a client to provide its certificate - during TLS negotiation and the client does not present a suitablle - certifcate (e.g. one that can be validated), the server MAY use a + + If an LDAP server requests a client to provide its certificate + during TLS negotiation and the client does not present a suitable + certificate (e.g. one that can be validated), the server may use a local security policy to determine whether to successfully complete TLS negotiation. + If the client provides a certificate that can be validated, information in the certificate may be used by the server in establishing the client's authorization identity by use of the SASL - external mechanism as discussed in Section 9. + EXTERNAL mechanism as discussed in Section 9. -3.1.5. Discovery of Resultant Security Level - After a TLS connection is established on an LDAP connection, both - parties must individually decide whether or not to continue based on - the security level achieved. The procedure for ascertaining the TLS - connection's security level is implementation dependent. +Harrison Expires April 2005 [Page 8] +Internet-Draft LDAP Authentication Methods 25 October 2004 + +3.1.5. Discovery of Resultant Security Level + + + After a TLS connection is established on an LDAP connection, both + parties are to individually decide whether or not to continue based + on the security level achieved. The procedure for ascertaining the + TLS connection's security level is implementation dependent. -Harrison Expires February 2005 [Page 8] - -Internet-Draft LDAP Authentication Methods 16 July 2004 If the client or server decides that the security level is not high enough for it to continue, it SHOULD gracefully close the TLS @@ -472,36 +570,45 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 may then close the connection, attempt to StartTLS again, send an unbind request, or send any other LDAP request. + 3.1.6. Server Identity Check + The client MUST check its understanding of the server's hostname against the server's identity as presented in the server's Certificate message in order to prevent man-in-the-middle attacks. + Matching is performed according to these rules: + - The client MUST use the server name provided by the user (or other trusted entity) as the value to compare against the server name as expressed in the server's certificate. A hostname derived from user input is to be considered provided by the user only if derived in a secure fashion (e.g., DNSSEC). + - If a subjectAltName extension of type dNSName is present in the certificate, it SHOULD be used as the source of the server's identity. + - The string values to be compared MUST be prepared according to the rules described in [Matching]. + - The "*" wildcard character is allowed. If present, it applies only to the left-most name component. + For example, *.bar.com would match a.bar.com and b.bar.com, but it would not match a.x.bar.com nor would it match bar.com. If more than one identity of a given type is present in the certificate (e.g. more than one dNSName name), a match in any one of the set is considered acceptable. + If the hostname does not match the dNSName-based identity in the certificate per the above check, user-oriented clients SHOULD either notify the user (clients may give the user the opportunity to @@ -510,19 +617,22 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 Automated clients SHOULD close the connection, returning and/or logging an error indicating that the server's identity is suspect. + + + +Harrison Expires April 2005 [Page 9] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + Beyond the server identity checks described in this section, clients SHOULD be prepared to do further checking to ensure that the server is authorized to provide the service it is observed to provide. The client may need to make use of local policy information in making this determination. -3.1.7. Refresh of Server Capabilities Information - +3.1.7. Refresh of Server Capabilities Information -Harrison Expires February 2005 [Page 9] - -Internet-Draft LDAP Authentication Methods 16 July 2004 Upon TLS session establishment, the client SHOULD discard or refresh all information about the server it obtained prior to the initiation @@ -531,14 +641,17 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 altered any server capabilities information retrieved prior to TLS establishment. + The server may advertise different capabilities after TLS establishment. In particular, the value of supportedSASLMechanisms may be different after TLS has been negotiated (specifically, the EXTERNAL and PLAIN [PLAIN] mechanisms are likely to be listed only after a TLS negotiation has been performed). + 3.2. Effects of TLS on a Client's Authorization Identity + This section describes the effects on a client's authorization identity brought about by establishing TLS on an LDAP connection. The default effects are described first, and next the facilities for @@ -546,159 +659,194 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 error conditions. Finally, the effects of closing the TLS connection are described. + Authorization identities and related concepts are described in - Appendix C. + Appendix B. + 3.2.1. TLS Connection Establishment Effects - The decision to keep or invalidate the established LDAP association - (section 12) after TLS connection establishment is a matter of local - server policy. + + The decision to keep or invalidate the established state of the + association (section 4.3) after TLS connection establishment is a + matter of local server policy. + 3.2.2. Client Assertion of Authorization Identity + After successfully establishing a TLS session, a client may request that its certificate exchanged during the TLS establishment be - utilized to determine the authorization identity of the LDAP - association. The client accomplishes this via an LDAP Bind request - specifying a SASL mechanism of EXTERNAL [SASL] (section 9). + utilized to determine the authorization identity of the association. + The client accomplishes this via an LDAP Bind request specifying a + SASL mechanism of EXTERNAL [SASL] (section 10). + 3.2.3. TLS Connection Closure Effects - The decision to keep or invalidate the established LDAP association - after TLS closure is a matter of local server policy. + + The decision to keep or invalidate the established state of the + association after TLS closure is a matter of local server policy. + 3.3. TLS Ciphersuites + + +Harrison Expires April 2005 [Page 10] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + Several issues should be considered when selecting TLS ciphersuites that are appropriate for use in a given circumstance. These issues include the following: + - The ciphersuite's ability to provide adequate confidentiality protection for passwords and other data sent over the LDAP connection. Client and server implementers should recognize that some TLS ciphersuites provide no confidentiality protection - -Harrison Expires February 2005 [Page 10] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - while other ciphersuites that do provide confidentiality protection may be vulnerable to being cracked using brute force methods, especially in light of ever-increasing CPU speeds that reduce the time needed to successfully mount such attacks. + Client and server implementers should carefully consider the value of the password or data being protected versus the level of confidentially protection provided by the ciphersuite to ensure that the level of protection afforded by the ciphersuite is appropriate. + - The ciphersuite's vulnerability (or lack thereof) to man-in-the- middle attacks. Ciphersuites vulnerable to man-in-the-middle attacks SHOULD NOT be used to protect passwords or sensitive data, unless the network configuration is such that the danger of a man-in-the-middle attack is tolerable. + 3.3.1. TLS Ciphersuites Recommendations + [[TODO: Kurt will have someone from security to look at this and will propose how to handle discussion of specific TLS ciphersuites in this draft.]] + As of the writing of this document, the following recommendations regarding TLS ciphersuites are applicable. Because circumstances are constantly changing, this list must not be considered exhaustive, but is hoped that it will serve as a useful starting point for implementers. + The following ciphersuites defined in [TLS] MUST NOT be used for confidentiality protection of passwords or data: + TLS_NULL_WITH_NULL_NULL TLS_RSA_WITH_NULL_MD5 TLS_RSA_WITH_NULL_SHA + The following ciphersuites defined in [TLS] can be cracked easily (less than a day of CPU time on a standard CPU in 2000) and are NOT RECOMMENDED for use in confidentiality protection of passwords or data: + TLS_RSA_EXPORT_WITH_RC4_40_MD5 TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 TLS_RSA_EXPORT_WITH_DES40_CBC_SHA TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA + + +Harrison Expires April 2005 [Page 11] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA + The following ciphersuites are vulnerable to man-in-the-middle attacks: -Harrison Expires February 2005 [Page 11] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 TLS_DH_anon_WITH_RC4_128_MD5 TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA TLS_DH_anon_WITH_DES_CBC_SHA TLS_DH_anon_WITH_3DES_EDE_CBC_SHA -4. LDAP Associations - Every LDAP connection has an associated authentication and - authorization state referred to as the "LDAP association". The Bind - operation defined in section 4.2 of [Protocol] and discussed further - in section 5 below allows authentication information to be exchanged - between the client and server to set the authentication and - authorization state and thus establish a new LDAP association. +4. Associations + + + Every LDAP connection has an associated authorization state referred + to as the "association". The Bind operation defined in section 4.2 + of [Protocol] and discussed further in section 5 below allows + information to be exchanged between the client and server to change + the authorization state of the association. + + +4.1. Anonymous Association on Unbound Connections -4.1. Anonymous LDAP Association on Unbound Connections Prior to the successful completion of a Bind operation and during - any subsequent authentication exchange, the session has an anonymous - LDAP association. Among other things this implies that the client - need not send a Bind Request in the first PDU of the connection. The - client may send any operation request prior to binding, and the - server MUST treat it as if it had been performed after an anonymous - bind operation (section 6). This authentication state on an LDAP - association is sometimes referred to as an implied anonymous bind. + any subsequent authentication exchange, the association has an + anonymous authorization state. Among other things this implies that + the client need not send a Bind Request in the first PDU of the + connection. The client may send any operation request prior to + binding, and the server MUST treat it as if it had been performed + after an anonymous bind operation (section 6). This association + state is sometimes referred to as an implied anonymous bind. + -4.2. Anonymous LDAP Association After Failed Bind +4.2. Anonymous Association After Failed Bind - Upon receipt of a Bind request, the LDAP association is moved to an + + Upon receipt of a Bind request, the association is moved to an anonymous state and only upon successful completion of the authentication exchange (and the Bind operation) is the association moved to an authenticated state. Thus, a failed Bind operation - produces an anonymous LDAP association on the session. + produces an anonymous association. + 4.3. Invalidated Associations - The server may invalidate the LDAP association at any time, e.g. if - the established security association between the client and server - has unexpectedly failed or been compromised. The association - remains invalidated until the next bind request. While the - association is invalidated, the server may reject any operation - request other than Bind, Unbind, and StartTLS by responding with a - resultCode of strongAuthRequired to indicate that the client needs - to bind to reestablish its authentication state before the server - will attempt to perform the requested operation. This behavior is - explained here to help client implementers properly understand and - react to this situation. + + The server may move the association to an invalidated state at any + time, e.g. if an established security layer between the client and + server has unexpectedly failed or been compromised. While the + connection has an invalid association, the server may reject any + operation request other than Bind, Unbind, and StartTLS by + responding with a resultCode of strongAuthRequired to indicate that + the server requires stronger authentication before it will attempt + to perform the requested operation. In practice, this means that the + client needs to bind to(re)establish a suitably strong authorization + + + + +Harrison Expires April 2005 [Page 12] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + state on the association before the server will attempt to perform + the requested operation. + 5. Bind Operation + The Bind operation ([Protocol] section 4.2) allows authentication information to be exchanged between the client and server to - establish a new LDAP association. - -Harrison Expires February 2005 [Page 12] - -Internet-Draft LDAP Authentication Methods 16 July 2004 + establish a new authorization state on the association. The Bind request typically specifies the desired authentication @@ -707,126 +855,157 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 specified, the server derives it from the authentication identity in an implementation-specific manner. + If the authorization identity is specified the server MUST verify that the client's authentication identity is permitted to assume (e.g. proxy for) the asserted authorization identity. The server MUST reject the Bind operation with an invalidCredentials resultCode in the Bind response if the client is not so authorized. + 5.1. Simple Authentication Choice + The simple authentication choice of the Bind Operation provides three authentication mechanisms: + 1. an anonymous authentication mechanism (section 6), + 2. an unauthenticated authentication mechanism (section 7), and + 3. a simple authentication mechanism using credentials consisting of a name (in the form of an LDAP distinguished name [LDAPDN]) - and a password (section X). + and a password (section 8). + 5.2. SASL Authentication Choice + The sasl authentication choice of the Bind Operation provides facilities for using any SASL mechanism (sections 9-11) including authentication mechanisms and other services (e.g. data security services). + 6. Anonymous Authentication Mechanism of Simple Bind + An LDAP client may use the anonymous authentication mechanism of the - simple Bind choice to explicitly establish an anonymous LDAP - association by sending a Bind request with a name value of zero - length and with the simple authentication choice containing a - password value of zero length. + simple Bind choice to explicitly establish an anonymous association + by sending a Bind request with a name value of zero length and with + the simple authentication choice containing a password value of zero + length. + 7. Unauthenticated Authentication Mechanism of Simple Bind + An LDAP client may use the unauthenticated authentication mechanism - of the simple Bind choice to establish an anonymous LDAP association - by sending a Bind request with a name value, a distinguished name in + of the simple Bind choice to establish an anonymous association by + sending a Bind request with a name value, a distinguished name in + + +Harrison Expires April 2005 [Page 13] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + LDAP string form [LDAPDN], of non-zero length, and specifying the the simple authentication choice containing a password value of zero length. + Unauthenticated binds can have significant security issues (see - section 14). Servers SHOULD by default reject unauthenticated bind + section 12.3). Servers SHOULD by default reject unauthenticated bind requests with a resultCode of invalidCredentials, and clients may - - -Harrison Expires February 2005 [Page 13] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - need to actively detect situations where they would unintentionally make an unauthenticated bind request. + 8. Simple Authentication Mechanism of Simple Bind + An LDAP client may use the simple authentication mechanism of the - simple Bind choice to establish an authenticated LDAP association by + simple Bind choice to establish an authenticated association by sending a Bind request with a name value, a distinguished name in LDAP string form [LDAPDN], and specifying the simple authentication choice containing an OCTET STRING password value of non-zero length. + Servers that map the DN sent in the bind request to a directory - entry with an associated set of one or more passwords, will compare - the presented password to the set of passwords associated with that - entry. The presented password is considered valid if it matches any - member of this set. - - If the DN is not valid, or the password is not valid for the DN, or - the server otherwise considers the credentials to be invalid, the - server is to return the invalidCredentials result code. The server - is only to return success result code when the credentials are valid - and the server is willing to provide service to the entity these - credentials identify. - - Server behavior is undefined for Bind requests with a zero-length - name value and specifying the simple authentication choice with a - value of non-zero length. + entry with an associated set of one or more passwords used with this + mechanism, will compare the presented password to that set of + passwords. The presented password is considered valid if it matches + any member of this set. + + + If the DN is syntactically invalid, the server returns the + invalidDNSyntax result code. If the DN is syntactically correct but + not valid for purposes of authentication, or the password is not + valid for the DN, or the server otherwise considers the credentials + to be invalid, the server returns the invalidCredentials result + code. The server is only to return the success result code when the + credentials are valid and the server is willing to provide service + to the entity these credentials identify. + + + Server behavior is undefined for bind requests specifying the simple + authentication mechanism with a zero-length name value and a + password value of non-zero length. + + The simple authentication mechanism of simple bind is not suitable for authentication in environments where there is no network or - transport layer confidentiality. LDAP implementations MUST be - capable of protecting it by establish::qment of TLS (as discussed in - section 3) or other suitable data confidentiality and data integrity - protection(e.g. IPSec). LDAP implementations - SHOULD support authentication with the "simple" authentication - choice when the connection is protected against eavesdropping using - TLS, as defined in section 4. LDAP implementations SHOULD NOT - support authentication with the "simple" authentication choice - unless the data on the connection is protected using TLS or other - data confidentiality and data integrity protection. + transport layer confidentiality. LDAP implementations SHALL NOT + support this mechanism unless they are capable of protecting it by + establishment of TLS (as discussed in section 3) or other suitable + data confidentiality and data integrity protection(e.g. IPSec). LDAP + implementations SHOULD support authentication with the "simple" + authentication choice when the connection is protected against + eavesdropping using TLS, as defined in section 3. LDAP + implementations SHOULD NOT support authentication with the "simple" + authentication choice unless the data on the connection is protected + using TLS or other data confidentiality and data integrity + protection. + 9. SASL Protocol Profile + + +Harrison Expires April 2005 [Page 14] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + LDAP allows authentication via any SASL mechanism [SASL]. As LDAP includes native anonymous and simple (plain text) authentication methods, the ANONYMOUS [ANONYMOUS] and PLAIN [PLAIN] SASL mechanisms are typically not used with LDAP. + Each protocol that utilizes SASL services is required to supply certain information profiling the way they are exposed through the protocol ([SASL] section 5). This section explains how each of these profiling requirements are met by LDAP. -9.1. SASL Service Name for LDAP -Harrison Expires February 2005 [Page 14] - -Internet-Draft LDAP Authentication Methods 16 July 2004 +9.1. SASL Service Name for LDAP The SASL service name for LDAP is "ldap", which has been registered - with the IANA as a GSSAPI service name. + with the IANA as a SASL service name. + 9.2. SASL Authentication Initiation and Protocol Exchange + SASL authentication is initiated via an LDAP bind request ([Protocol] section 4.2) with the following parameters: + - The version is 3. - The AuthenticationChoice is sasl. - The mechanism element of the SaslCredentials sequence contains @@ -836,6 +1015,7 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 mechanisms that are defined to have the client send data first (see [SASL] sections 5 and 5.1). + In general, a SASL authentication protocol exchange consists of a series of server challenges and client responses, the contents of which are specific to and defined by the SASL mechanism. Thus for @@ -847,6 +1027,7 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 client to send a new bind request with the same sasl mechanism to continue the authentication process. + To the LDAP protocol, these challenges and responses are opaque binary tokens of arbitrary length. LDAP servers use the serverSaslCreds field, an OCTET STRING, in a bind response message @@ -856,11 +1037,18 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 protocols where SASL is used, LDAP is not text-based, thus no Base64 transformations are performed on these challenge and response values. + Clients sending a bind request with the sasl choice selected SHOULD send an zero-length value in the name field. Servers receiving a bind request with the sasl choice selected SHALL ignore any value in the name field. + + +Harrison Expires April 2005 [Page 15] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + A client may abort a SASL bind negotiation by sending a BindRequest with a different value in the mechanism field of SaslCredentials, or an AuthenticationChoice other than sasl. @@ -872,15 +1060,11 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 mechanism. - -Harrison Expires February 2005 [Page 15] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - The server indicates completion of the SASL challenge-response exchange by responding with a bind response in which the resultCode is either success, or an error indication. + The serverSaslCreds field in the BindResponse can be used to include an optional challenge with a success notification for mechanisms which are defined to have the server send additional data along with @@ -889,21 +1073,26 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 SHALL omit the serverSaslCreds field (rather than including the field with a zero-length value). + 9.3. Octet Where Negotiated Security Mechanisms Take Effect + SASL security layers take effect following the transmission by the server and reception by the client of the final successful BindResponse in the exchange. - Once a SASL security layer providing integrity or confidentiality - services takes effect, the layer remains in effect until a new layer - is installed (i.e. at the first octet following the final - BindResponse of the bind operation that caused the new layer to take - effect). Thus, an established SASL security layer is not affected - by a failed or non-SASL Bind. + + Once a SASL security layer providing data integrity or + confidentiality services takes effect, the layer remains in effect + until a new layer is installed (i.e. at the first octet following + the final BindResponse of the bind operation that caused the new + layer to take effect). Thus, an established SASL security layer is + not affected by a failed or non-SASL Bind. + 9.4. Determination of Supported SASL Mechanisms + Clients may determine the SASL mechanisms a server supports by reading the supportedSASLMechanisms attribute from the root DSE (DSA-Specific Entry) ([Models] section 5.1). The values of this @@ -912,18 +1101,28 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 anonymously-bound client to retrieve the supportedSASLMechanisms attribute of the root DSE. + Because SASL mechanisms provide critical security functions, clients and servers should be configurable to specify what mechanisms are acceptable and allow only those mechanisms to be used. Both clients and servers must confirm that the negotiated security level meets their requirements before proceeding to use the connection. + 9.5. Rules for Using SASL Security Layers + + + +Harrison Expires April 2005 [Page 16] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + If a SASL security layer is negotiated, the client SHOULD discard information about the server it obtained prior to the initiation of the SASL negotiation and not obtained through secure mechanisms. + If a lower level security layer (such as TLS) is negotiated, any SASL security services SHALL be layered on top of such security layers regardless of the order of their negotiation. In all other @@ -932,42 +1131,45 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 effect then removing the SASL security service does not affect the continuing service of TLS and vice versa. -Harrison Expires February 2005 [Page 16] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - 9.6 Support for Multiple Authentications + LDAP supports multiple SASL authentications as defined in [SASL] section 6.3. -10. SASL EXTERNAL Mechanism - A client can use the EXTERNAL SASL [SASL] mechanism to request the +10. SASL EXTERNAL Authentication Mechanism + + + A client can use the SASL EXTERNAL [SASL] mechanism to request the LDAP server to authenticate and establish a resulting authorization identity using security credentials exchanged by a lower security layer (such as by TLS authentication or IP-level security [RFC2401]). - The resulting authentication identity of the LDAP association is - derived from the security credentials in an implementation-specific - manner. If the client's authentication credentials have not been - established at a lower security layer, the SASL EXTERNAL bind MUST - fail with a resultCode of inappropriateAuthentication. Although - this situation has the effect of leaving the LDAP association in an - anonymous state (section 5), the state of any established security - layer is unaffected. - A client may either implicitly request that its LDAP authorization + The authorization identity used to determine the state of the + association is derived from the security credentials in an + implementation-specific manner. If the client's authentication + credentials have not been established at a lower security layer, the + SASL EXTERNAL bind MUST fail with a resultCode of + inappropriateAuthentication. Although this situation has the effect + of leaving the association in an anonymous state (section 5), the + state of any established security layer is unaffected. + + + A client may either implicitly request that its authorization identity be derived from its authentication credentials exchanged at a lower security layer or it may explicitly provide an authorization identity and assert that it be used in combination with those authentication credentials. The former is known as an implicit assertion, and the latter as an explicit assertion. + 10.1. Implicit Assertion + An implicit authorization identity assertion is performed by invoking a Bind request of the SASL form using the EXTERNAL mechanism name that does not include the optional credentials octet @@ -978,52 +1180,65 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 according to local policy. The underlying mechanics of how this is accomplished are implementation specific. + 10.2. Explicit Assertion + +Harrison Expires April 2005 [Page 17] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + An explicit authorization identity assertion is performed by invoking a Bind request of the SASL form using the EXTERNAL mechanism name that includes the credentials octet string. This - string MUST be constructed as documented in section 3.4.1. + string MUST be constructed as documented in section 10.4. + 10.3. SASL Authorization Identity + When the EXTERNAL SASL mechanism is being negotiated, if the SaslCredentials credentials field is present, it contains an authorization identity. Other mechanisms define the location of the - -Harrison Expires February 2005 [Page 17] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - authorization identity in the credentials field. In either case, the authorization identity is represented in the authzId form described below. + 10.4. SASL Authorization Identity Syntax + The authorization identity is a string of UTF-8 [RFC3629] encoded [Unicode] characters corresponding to the following ABNF [RFC2234] grammar: - authzId = dnAuthzId / uAuthzId - DNCOLON = %x64 %x6e %x3a ; "dn:" - UCOLON = %x75 %x3a ; "u:" + authzId ::= dnAuthzId / uAuthzId + + + DNCOLON ::= %x64 %x6e %x3a ; "dn:" + UCOLON ::= %x75 %x3a ; "u:" + ; distinguished-name-based authz id. - dnAuthzId = DNCOLON distinguishedName + dnAuthzId ::= DNCOLON distinguishedName + ; unspecified authorization id, UTF-8 encoded. - uAuthzId = UCOLON userid - userid = *UTF8 ; syntax unspecified + uAuthzId ::= UCOLON userid + userid ::= *UTF8 ; syntax unspecified + where the production is defined in section 3 of [LDAPDN] and production is defined in section 1.3 of [Models]. + In order to support additional specific authorization identity forms, future updates to this specification may add new choices supporting other forms of the authzId production. + The dnAuthzId choice is used to assert authorization identities in the form of a distinguished name to be matched in accordance with the distinguishedNameMatch matching rule [Syntaxes]. The decision to @@ -1032,37 +1247,44 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 section 4.2). For this reason there is no requirement that the asserted dn be that of an entry in the directory. + The uAuthzId choice allows clients to assert an authorization identity that is not in distinguished name form. The format of userid is defined as only a sequence of UTF-8 [RFC3629] encoded [Unicode] characters, and any further interpretation is a local matter. To compare uAuthzID values, each uAuthzID value MUST be + + + +Harrison Expires April 2005 [Page 18] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + prepared using [SASLPrep] and then the two values are compared octet-wise. + For example, the userid could identify a user of a specific directory service, be a login name, or be an email address. A uAuthzId SHOULD NOT be assumed to be globally unique. -11. SASL DIGEST-MD5 Mechanism - - LDAP servers that implement any authentication method or mechanism - other than simple anonymous bind MUST implement the SASL +11. SASL DIGEST-MD5 Authentication Mechanism -Harrison Expires February 2005 [Page 18] - -Internet-Draft LDAP Authentication Methods 16 July 2004 + LDAP servers that implement any authentication method or mechanism + other than simple anonymous bind MUST implement the SASL DIGEST-MD5 mechanism [DIGEST-MD5]. This provides client authentication with protection against passive eavesdropping attacks but does not provide protection against man-in-the-middle attacks. DIGEST-MD5 also provides data integrity and data confidentiality capabilities. + Support for subsequent authentication ([DIGEST-MD5] section 2.2) is OPTIONAL in clients and servers. + Implementers must take care to ensure that they maintain the semantics of the DIGEST-MD5 specification even when handling data that has different semantics in the LDAP protocol. @@ -1081,25 +1303,38 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 equivalent if they represent username values in DIGEST-MD5 because [SASLPrep] semantics are used by DIGEST-MD5. + 12. Security Considerations + Security issues are discussed throughout this document. The unsurprising conclusion is that security is an integral and necessary part of LDAP. This section discusses a number of LDAP- related security considerations. + 12.1. General LDAP Security Considerations + LDAP itself provides no security or protection from accessing or updating the directory by other means than through the LDAP protocol, e.g. from inspection by database administrators. Access control SHOULD always be applied when reading sensitive information or updating directory information. - Servers can minimize denial of service attacks by timing out idle - connections, and returning the unwillingToPerform resultCode rather - than performing computationally expensive operations requested by - unauthorized clients. + + + +Harrison Expires April 2005 [Page 19] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + Servers can minimize denial of service attacks by providing the + ability to configure and enforce administrative limits on + operations, timing out idle connections and returning the + unwillingToPerform resultCode rather than performing computationally + expensive operations requested by unauthorized clients. + A connection on which the client has not established connection integrity and privacy services (e.g via StartTLS, IPSec or a @@ -1109,69 +1344,70 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 these attacks by using data protection services as discussed in this document. -Harrison Expires February 2005 [Page 19] - -Internet-Draft LDAP Authentication Methods 16 July 2004 +12.1.1. Password-related Security Considerations -12.1.1.Password-related Security Considerations LDAP allows multi-valued password attributes. In systems where entries are expected to have one and only one password, administrative controls should be provided to enforce this behavior. + The use of clear text passwords and other unprotected authentication credentials is strongly discouraged over open networks when the underlying transport service cannot guarantee confidentiality. + The transmission of passwords in the clear--typically for authentication or modification--poses a significant security risk. This risk can be avoided by using SASL authentication [SASL] mechanisms that do not transmit passwords in the clear or by - negotiating transport or session layer confidentiality services + negotiating transport or session layer data confidentiality services before transmitting password values. + To mitigate the security risks associated with the transfer of passwords, a server implementation that supports any password-based authentication mechanism that transmits passwords in the clear MUST support a policy mechanism that at the time of authentication or password modification, requires: + A StartTLS encryption layer has been successfully negotiated. + OR - Some other confidentiality mechanism that protects the password - value from snooping has been provided. + + Some other data confidentiality mechanism that protects the + password value from snooping has been provided. + OR + The server returns a resultCode of confidentialityRequired for the operation (i.e. simple bind with password value, SASL bind transmitting a password value in the clear, add or modify including a userPassword value, etc.), even if the password value is correct. + 12.2. StartTLS Security Considerations - The goals of using the TLS [TLS] protocol with LDAP are to ensure - connection confidentiality and integrity, and to optionally provide - for authentication. TLS expressly provides these capabilities - (although the authentication services of TLS are available to LDAP - only in combination with the SASL EXTERNAL authentication method, - and then only if the SASL EXTERNAL implementation chooses to make - use of the TLS credentials). + + +Harrison Expires April 2005 [Page 20] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + All security gained via use of the StartTLS operation is gained by the use of TLS itself. The StartTLS operation, on its own, does not provide any additional security. - -Harrison Expires February 2005 [Page 20] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - The level of security provided though the use of TLS depends directly on both the quality of the TLS implementation used and the style of usage of that implementation. Additionally, a man-in-the- @@ -1182,147 +1418,188 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 connection. For example, the security level of the TLS connection might have been negotiated down to plaintext. - Clients SHOULD either warn the user when the security level - achieved does not provide data confidentiality and/or integrity - protection, or be configurable to refuse to proceed without an - acceptable level of security. + + Clients SHOULD by default either warn the user when the security + level achieved does not provide an acceptable level of data + confidentiality and/or data integrity protection, or be configured + to refuse to proceed without an acceptable level of security. + Server implementors SHOULD allow server administrators to elect whether and when data confidentiality and integrity are required, as - well as elect whether TLS authentication of the client is required. + well as elect whether authentication of the client during the TLS + handshake is required. + Implementers should be aware of and understand TLS security considerations as discussed in the TLS specification [TLS]. + 12.3. Unauthenticated Mechanism Security Considerations + Operational experience shows that clients can (and frequently do) misuse the unauthenticated authentication mechanism of simple bind (see section 7). For example, a client program might make a decision to grant access to non-directory information on the basis of completing a successful bind operation. LDAP server - implementations will return a success response to an unauthenticated + implementations may return a success response to an unauthenticated bind request thus leaving the client with the impression that the server has successfully authenticated the identity represented by - the user name, when in effect, an anonymous LDAP association has - been established. Clients that use the results from a simple bind + the user name, when in effect, an anonymous association has been + established. Clients that use the results from a simple bind operation to make authorization decisions should actively detect unauthenticated bind requests (by verifying that the supplied password is not empty) and react appropriately. + 12.4. Simple Mechanism Security Considerations + The simple authentication mechanism of simple bind discloses the - password to server, which is an inherent security risk. There are - other mechanisms such as DIGEST-MD5 that do not disclose password to - server. + password to the server, which is an inherent security risk. There + are other mechanisms such as DIGEST-MD5 that do not disclose + password to server. + 12.5. SASL DIGEST-MD5 Mechanism Security Considerations + + +Harrison Expires April 2005 [Page 21] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + The SASL DIGEST-MD5 mechanism is prone to the qop substitution - attack, as discussed in 6.2 of RFC 2831. The qop substitution - attack can be mitigated (as discussed in 6.2 of RFC 2831). + attack, as discussed in 3.6 of [DIGEST-MD5]. The qop substitution + attack can be mitigated (as discussed in 3.6 of [DIGEST-MD5]). + The SASL DIGEST-MD5 mechanism [DIGEST-MD5] provides client authentication with protection against passive eavesdropping attacks but does not provide protection against man-in-the-middle attacks. -Harrison Expires February 2005 [Page 21] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Implementers should be aware of and understand DIGEST-MD5 security considerations as discussed in the DIGEST-MD5 specification [DIGEST- MD5]. + 12.6. Related Security Considerations + + Additional security considerations relating to the various authentication methods and mechanisms discussed in this document - apply and can be found in [SASL], [SASLPrep], [StringPrep] and + apply and can be found in [SASL], [SASLPrep], [StringPrep] and [RFC3629]. + 13. IANA Considerations + The following IANA considerations apply to this document: - Please update the GSSAPI service name registry to point to [Roadmap] - and this document. + + It is requested that the IANA update the LDAP Protocol Mechanism + registry to indicate that this document and [Protocol] provide the + definitive technical specification for the StartTLS + (1.3.6.1.4.1.1466.20037) extended operation. + [[TODO: add any missing IANA Considerations.]] + Acknowledgments + This document combines information originally contained in RFC 2829 and RFC 2830. The editor acknowledges the work of Harald Tveit Alvestrand, Jeff Hodges, Tim Howes, Steve Kille, RL "Bob" Morgan , and Mark Wahl, each of whom authored one or more of these documents. + This document is based upon input of the IETF LDAP Revision working group. The contributions and suggestions made by its members in shaping the contents and technical accuracy of this document is greatly appreciated. + Normative References + [[Note to the RFC Editor: please replace the citation tags used in referencing Internet-Drafts with tags of the form RFCnnnn.]] + [RFC2234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. + [DIGEST-MD5] Leach, P. C. Newman, and A. Melnikov, "Using Digest Authentication as a SASL Mechanism", draft-ietf-sasl- rfc2831bis-xx.txt, a work in progress. + + +Harrison Expires April 2005 [Page 22] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + [RFC2119] Bradner, S., "Key Words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. + [LDAPDN] Zeilenga, Kurt D. (editor), "LDAP: String Representation of Distinguished Names", draft-ietf- ldapbis-dn-xx.txt, a work in progress. + [Matching] Hoffman, Paul and Steve Hanna, "Matching Text Strings in PKIX Certificates", draft-hoffman-pkix-stringmatch- xx.txt, a work in progress. -Harrison Expires February 2005 [Page 22] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - [Models] Zeilenga, Kurt D. (editor), "LDAP: Directory Information Models", draft-ietf-ldapbis-models-xx.txt, a work in progress. + [Protocol] Sermersheim, J., "LDAP: The Protocol", draft-ietf- ldapbis-protocol-xx.txt, a work in progress. + [Roadmap] K. Zeilenga, "LDAP: Technical Specification Road Map", draft-ietf-ldapbis-roadmap-xx.txt, a work in progress. + [SASL] Melnikov, A. (editor), "Simple Authentication and Security Layer (SASL)", draft-ietf-sasl-rfc2222bis- xx.txt, a work in progress. + [SASLPrep] Zeilenga, K., "Stringprep profile for user names and passwords", draft-ietf-sasl-saslprep-xx.txt, (a work in progress). - [StringPrep] M. Blanchet, "Preparation of Internationalized - Strings ('stringprep')", draft-hoffman-rfc3454bis- - xx.txt, a work in progress. + + [StringPrep] M. Blanchet, "Preparation of Internationalized Strings + ('stringprep')", draft-hoffman-rfc3454bis-xx.txt, a + work in progress. + [Syntaxes] Legg, S. (editor), "LDAP: Syntaxes and Matching Rules", draft-ietf-ldapbis-syntaxes-xx.txt, a work in progress. + [TLS] Dierks, T. and C. Allen. "The TLS Protocol Version 1.1", draft-ietf-tls-rfc2246-bis-xx.txt, a work in progress. + [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC 3629, STD 63, November 2003. + [Unicode] The Unicode Consortium, "The Unicode Standard, Version 3.2.0" is defined by "The Unicode Standard, Version 3.0" (Reading, MA, Addison-Wesley, 2000. ISBN 0-201- @@ -1332,28 +1609,34 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 "Unicode Standard Annex #28: Unicode 3.2" (http://www.unicode.org/reports/tr28/). + Informative References + + +Harrison Expires April 2005 [Page 23] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + [ANONYMOUS] Zeilenga, K.,"Anonymous SASL Mechanism", draft- zeilenga-sasl-anon-xx.txt, a work in progress. + [RFC2828] Shirey, R., "Internet Security Glossary", RFC 2828, May 2000. + [PLAIN] Zeilenga, K.,"Plain SASL Mechanism", draft-zeilenga- sasl-plain-xx.txt, a work in progress. - -Harrison Expires February 2005 [Page 23] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - [RFC2401] Kent, S. and R. Atkinson, "Security Architecture for the Internet Protocol", RFC 2401, November 1998. + Author's Address + Roger Harrison Novell, Inc. 1800 S. Novell Place @@ -1362,23 +1645,29 @@ Author's Address +1 801 861 2642 roger_harrison@novell.com -Appendix A. LDAP Association State Transition Tables + +Appendix A. Association State Transition Tables + This section provides a state transition table to represent a state - diagram for the various authentication and TLS states through which - an LDAP association may pass during the course of its existence and - the actions that cause these changes in state. + diagram for the various authentication states through which an + association may pass during the course of its existence and the + actions that cause these changes in state. + This section is based entirely on information found in this document and other documents that are part of the LDAP Technical Specification [Roadmap]. As such, it is strictly informational in nature. -A.1. LDAP Association States - The following table lists the valid LDAP association states and - provides a description of each state. The ID for each state is used - in the state transition table in section A.4. +A.1. Association States + + + The following table lists the valid association states and provides + a description of each state. The ID for each state is used in the + state transition table in section A.4. + ID State Description -- -------------------------------------------------------------- @@ -1391,46 +1680,56 @@ A.1. LDAP Association States S3 Authenticated SASL EXTERNAL, implicit authorization ID Authentication ID = J Authorization ID = Y + + + + +Harrison Expires April 2005 [Page 24] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + S4 Authenticated SASL EXTERNAL, explicit authorization ID Z Authentication ID = J Authorization ID = Z + S5 Invalidated -A.2. Actions that Affect LDAP Association State - The following table lists the actions that can affect the - authentication and authorization state of an LDAP association. The - ID for each action is used in the state transition table in section - A.4. +A.2. Actions that Affect Association State + + The following table lists the actions that can affect the + authentication and authorization state of an association. The ID for + each action is used in the state transition table in section A.4. -Harrison Expires February 2005 [Page 24] - -Internet-Draft LDAP Authentication Methods 16 July 2004 ID Action -- -------------------------------------------------------------- A1 Client bind request fails - A2 Client successfully performs anonymous simple bind - A3 Client successfully performs unauthenticated simple bind - A4 Client successfully performs simple bind with name and password + A2 Client successfully performs anonymous simple bind or + unauthenticated simple bind + A3 Client successfully performs simple bind with name and password OR SASL bind with any mechanism except EXTERNAL using an authentication ID = I that maps to authorization ID X - A5 Client Binds SASL EXTERNAL with implicit assertion of - authorization ID (section 9.1)]. The current authentication ID + A4 Client Binds SASL EXTERNAL with implicit assertion of + authorization ID (section 9.1). The current authentication ID maps to authorization ID = Y. - A6 Client Binds SASL EXTERNAL with explicit assertion of - authorization ID = Z (section 9.2)] - A7 Client StartTLS request fails - A8 Client StartTLS request succeeds - A9 Client or Server: graceful TLS removal + A5 Client Binds SASL EXTERNAL with explicit assertion of + authorization ID = Z (section 9.2). + A6 Client StartTLS request fails + A7 Client StartTLS request succeeds + A8 Client or Server: graceful TLS removal + A9 Server decides to invalidate current association state + + +A.3. Decisions Used in Making Association State Changes -A.3. Decisions Used in Making LDAP Association State Changes Certain changes in the authentication and authorization state of an - LDAP association are only allowed if the server can affirmatively - answer a question. These questions are applied as part of the - criteria for allowing or disallowing a state transition in the state - transition table in section A.4. + association are only allowed if the server can affirmatively answer + a question. These questions are applied as part of the criteria for + allowing or disallowing a state transition in the state transition + table in section A.4. + ID Decision Question -- -------------------------------------------------------------- @@ -1438,65 +1737,75 @@ A.3. Decisions Used in Making LDAP Association State Changes D2 Can lower-layer credentials for Auth ID "K" be mapped to asserted AuthZID "L"? -A.4. LDAP Association State Transition Table - The LDAP Association table below lists the the actions that could - affect authentication and authorization state of an LDAP association - and the resulting state of an LDAP association after a given action - occurs. +A.4. Association State Transition Table + + + The Association table below lists the the actions that could affect + the authorization state of an association and the resulting state of + an association after a given action occurs. + S1, the initial state for the state machine described in this table, - is the authentication state when an LDAP connection is initially + is the association state when an LDAP connection is initially established. - Next - Action State Comment - ------- ----- ------------------------------------------------- - A1 S1 Section 4 - A2 S1 Section 6 - A3 S1 Section 7 - A4 S2 Sections 8, 9 - A5, S1 Failed bind, section 10.1 - D1=no - A5, S3 - D1=yes -Harrison Expires February 2005 [Page 25] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - A6, S1 Failed bind, section 10.2 +Harrison Expires April 2005 [Page 25] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + Next State + Action Comment + ------------------ ----------- -------------------------------- + A1 S1 Section 4 + A2 S1 Sections 6 & 7 + A3 S2 Sections 8, 9 + A4, S1 Failed bind, section 10.1 + D1=no + A4, S3 + D1=yes + A5, S1 Failed bind, section 10.2 D1=no - A6, S1 Failed bind, section 10.2 - D1=yes, + A5, S1 Failed bind, section 10.2 + D1=yes, D2=no - A6, S4 - D1=yes, - D2=yes - A7 no [Protocol] section 4.14.2.2 - change - A8 no [Protocol] section 4.14.2.1 - change - A9 S1 [Protocol] section 4.14.3.1 + A5, S4 + D1=yes, D2=yes + A6 no change* [Protocol] section 4.14.2.2 + A7 no change* [Protocol] section 4.14.2.1 + A8 S1 [Protocol] section 4.14.3.1 + A9 S5 + + + * The server may invalidate the association after TLS + establishment or closure (section 3.2). + Appendix B. Authentication and Authorization Concepts + This appendix defines basic terms, concepts, and interrelationships regarding authentication, authorization, credentials, and identity. These concepts are used in describing how various security approaches are utilized in client authentication and authorization. + B.1. Access Control Policy + An access control policy is a set of rules defining the protection of resources, generally in terms of the capabilities of persons or other entities accessing those resources. Security objects and mechanisms, such as those described here, enable the expression of access control policies and their enforcement. + B.2. Access Control Factors + A request, when it is being processed by a server, may be associated with a wide variety of security-related factors (section 4.2 of [Protocol]). The server uses these factors to determine whether and @@ -1507,27 +1816,30 @@ B.2. Access Control Factors associated with the connection via which the request is transmitted, others (e.g. time of day) may be "environmental". + Access control policies are expressed in terms of access control factors. E.g., a request having ACFs i,j,k can perform operation Y + + +Harrison Expires April 2005 [Page 26] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + on resource Z. The set of ACFs that a server makes available for such expressions is implementation-specific. + B.3. Authentication, Credentials, Identity + Authentication credentials are the evidence supplied by one party to another, asserting the identity of the supplying party (e.g. a user) - who is attempting to establish an association with the other party - (typically a server). Authentication is the process of generating, - transmitting, and verifying these credentials and thus the identity - - + who is attempting to establish a new association state with the + other party (typically a server). Authentication is the process of + generating, transmitting, and verifying these credentials and thus + the identity they assert. An authentication identity is the name + presented in a credential. -Harrison Expires February 2005 [Page 26] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - - they assert. An authentication identity is the name presented in a - credential. There are many forms of authentication credentials -- the form used depends upon the particular authentication mechanism negotiated by @@ -1536,14 +1848,17 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 mechanism may constrain the form of authentication identities used with it. + B.4. Authorization Identity + An authorization identity is one kind of access control factor. It is the name of the user or other entity that requests that operations be performed. Access control policies are often expressed in terms of authorization identities; e.g., entity X can perform operation Y on resource Z. + The authorization identity bound to an association is often exactly the same as the authentication identity presented by the client, but it may be different. SASL allows clients to specify an authorization @@ -1556,120 +1871,162 @@ B.4. Authorization Identity server's access control policy, requiring a server-specific mapping to be done. The method by which a server composes and validates an authorization identity from the authentication credentials supplied - by a client is implementation-specific. + by a client is performed in an implementation-specific manner. + Appendix C. RFC 2829 Change History + This appendix lists the changes made to the text of RFC 2829 in preparing this document. + C.0. General Editorial Changes Version -00 + - Changed other instances of the term LDAP to LDAP where v3 of the protocol is implied. Also made all references to LDAP use the same wording. + + +Harrison Expires April 2005 [Page 27] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Miscellaneous grammatical changes to improve readability. + - Made capitalization in section headings consistent. + Version -01 + - Changed title to reflect inclusion of material from RFC 2830 and 2251. -C.1. Changes to Section 1 -Harrison Expires February 2005 [Page 27] - -Internet-Draft LDAP Authentication Methods 16 July 2004 +C.1. Changes to Section 1 Version -01 + - Moved conventions used in document to a separate section. + C.2. Changes to Section 2 + Version -01 + - Moved section to an appendix. + C.3. Changes to Section 3 + Version -01 + - Moved section to an appendix. + C.4 Changes to Section 4 + Version -00 + - Changed "Distinguished Name" to "LDAP distinguished name". + C.5. Changes to Section 5 + Version -00 + - Added the following sentence: "Servers SHOULD NOT allow clients with anonymous authentication to modify directory entries or access sensitive information in directory entries." + C.5.1. Changes to Section 5.1 + Version -00 + - Replaced the text describing the procedure for performing an anonymous bind (protocol) with a reference to section 4.2 of RFC 2251 (the protocol spec). + Version -01 + - Brought text describing procedure for performing an anonymous bind from section 4.2 of RFC 2251 bis. This text will be removed from the draft standard version of that document. + +Harrison Expires April 2005 [Page 28] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + C.6. Changes to Section 6. + Version -00 + Reorganized text in section 6.1 as follows: + 1. Added a new section (6.1) titled "Simple Authentication" and - moved one of two introductory paragra phs for section 6 into + moved one of two introductory paragraphs for section 6 into section 6.1. Added sentences to the paragraph indicating: -Harrison Expires February 2005 [Page 28] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - a. simple authentication is not suitable for environments where confidentiality is not available. + b. LDAP implementations SHOULD NOT support simple authentication unless confidentiality and data integrity mechanisms are in force. + 2. Moved first paragraph of section 6 (beginning with "LDAP implementations MUST support authentication with a password...") to section on Digest Authentication (Now section 6.2). + C.6.1. Changes to Section 6.1. + Version -00 Renamed section to 6.2 + - Added sentence from original section 6 indicating that the DIGEST-MD5 SASL mechanism is required for all conforming LDAP implementations + C.6.2. Changes to Section 6.2 + Version -00 + - Renamed section to 6.3 + - Reworded first paragraph to remove reference to user and the userPassword password attribute Made the first paragraph more general by simply saying that if a directory supports simple @@ -1677,160 +2034,216 @@ C.6.2. Changes to Section 6.2 following negotiation of a TLS ciphersuite that supports confidentiality. + - Replaced "the name of the user's entry" with "a DN" since not all bind operations are performed on behalf of a "user." + - Added Section 6.3.1 heading just prior to paragraph 5. + - Paragraph 5: replaced "The server" with "DSAs that map the DN sent in the bind request to a directory entry with a userPassword attribute." + C.6.3. Changes to section 6.3. + + +Harrison Expires April 2005 [Page 29] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + Version -00 + - Renamed to section 6.4. + C.7. Changes to section 7. + none -C.7.1. Changes to section 7.1. +C.7.1. Changes to section 7.1. -Harrison Expires February 2005 [Page 29] - -Internet-Draft LDAP Authentication Methods 16 July 2004 Version -00 + - Clarified the entity issuing a certificate by moving the phrase "to have issued the certificate" immediately after "Certification Authority." + C.8. Changes to section 8. + Version -00 + - Removed the first paragraph because simple authentication is covered explicitly in section 6. + - Added section 8.1. heading just prior to second paragraph. + - Added section 8.2. heading just prior to third paragraph. + - Added section 8.3. heading just prior to fourth paragraph. + Version -01 + - Moved entire section 8 of RFC 2829 into section 3.4 (Using SASL for Other Security Services) to bring material on SASL mechanisms together into one location. + C.9. Changes to section 9. + Version -00 + - Paragraph 2: changed "EXTERNAL mechanism" to "EXTERNAL SASL mechanism." + - Added section 9.1. heading. + - Modified a comment in the ABNF from "unspecified userid" to "unspecified authz id". + - Deleted sentence, "A utf8string is defined to be the UTF-8 encoding of one or more ISO 10646 characters," because it is redundant. + - Added section 9.1.1. heading. + - Added section 9.1.2. heading. + +Harrison Expires April 2005 [Page 30] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + Version -01 + - Moved entire section 9 to become section 3.5 so that it would be with other SASL material. + C.10. Changes to Section 10. - Version -00 + Version -00 -Harrison Expires February 2005 [Page 30] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Updated reference to cracking from a week of CPU time in 1997 to be a day of CPU time in 2000. + - Added text: "These ciphersuites are NOT RECOMMENDED for use... and server implementers SHOULD" to sentence just prior the second list of ciphersuites. + - Added text: "and MAY support other ciphersuites offering equivalent or better protection," to the last paragraph of the section. + C.11. Changes to Section 11. + Version -01 + - Moved to section 3.6 to be with other SASL material. + C.12. Changes to Section 12. + Version -00 + - Inserted new section 12 that specifies when SASL protections begin following SASL negotiation, etc. The original section 12 is renumbered to become section 13. + Version -01 + - Moved to section 3.7 to be with other SASL material. + C.13. Changes to Section 13 (original section 12). + None + Appendix D. RFC 2830 Change History + This appendix lists the changes made to the text of RFC 2830 in preparing this document. + D.0. General Editorial Changes + - Material showing the PDUs for the StartTLS response was broken out into a new section. + + + +Harrison Expires April 2005 [Page 31] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - The wording of the definition of the StartTLS request and StartTLS response was changed to make them parallel. NO changes were made to the ASN.1 definition or the associated values of the parameters. + - A separate section heading for graceful TLS closure was added for parallelism with section on abrupt TLS closure. -Appendix E. RFC 2251 Change History - +Appendix E. RFC 2251 Change History -Harrison Expires February 2005 [Page 31] - -Internet-Draft LDAP Authentication Methods 16 July 2004 This appendix lists the changes made to the text of RFC 2251 in preparing this document. + E.0. General Editorial Changes + - All material from section 4.2 of RFC 2251 was moved into this document. + - A new section was created for the Bind Request + - Section 4.2.1 of RFC 2251 (Sequencing Bind Request) was moved after the section on the Bind Response for parallelism with the presentation of the StartTLS operations. The section was also @@ -1841,162 +2254,213 @@ E.0. General Editorial Changes the discussion of the Bind operation (primarily sections 4.4 - 4.7). + Appendix F. Change History to Combined Document + F.1. Changes for draft-ldap-bis-authmeth-02 + General + - Added references to other LDAP standard documents, to sections within the document, and fixed broken references. + - General editorial changes--punctuation, spelling, formatting, etc. + Section 1. + - Added glossary of terms and added sub-section headings + Section 2. + - Clarified security mechanisms 3, 4, & 5 and brought language in line with IETF security glossary. + Section 3. + + + +Harrison Expires April 2005 [Page 32] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Brought language in requirement (3) in line with security glossary. + - Clarified that information fetched prior to initiation of TLS negotiation must be discarded + -Clarified that information fetched prior to initiation of SASL negotiation must be discarded + - Rewrote paragraph on SASL negotiation requirements to clarify intent -Harrison Expires February 2005 [Page 32] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Section 4.4. + - Added stipulation that sasl choice allows for any SASL mechanism not prohibited by this document. (Resolved conflict between this statement and one that prohibited use of ANONYMOUS and PLAIN SASL mechanisms.) + Section 5.3.6 + - Added a.x.bar.com to wildcard matching example on hostname check. + Section 6 - - Added LDAP Association State Transition Tables to show the - various states through which an LDAP association may pass along - with the actions and decisions required to traverse from state - to state. + + - Added Association State Transition Tables to show the various + states through which an association may pass along with the + actions and decisions required to traverse from state to state. + Appendix A + - Brought security terminology in line with IETF security glossary throughout the appendix. + F.2. Changes for draft-ldapbis-authmeth-03 + General + - Added introductory notes and changed title of document and references to conform to WG chair suggestions for the overall technical specification. + - Several issues--H.13, H.14, H.16, H.17--were resolved without requiring changes to the document. + Section 3 + - Removed reference to /etc/passwd file and associated text. + Section 4 + - Removed sections 4.1, 4.2 and parts of section 4.3. This information was being duplicated in the protocol specification and will now reside there permanently. + + +Harrison Expires April 2005 [Page 33] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + Section 4.2 + - changed words, "not recommended" to "strongly discouraged" + Section 4.3 + - Based on ldapbis WG discussion at IETF52 two sentences were added indicating that clients SHOULD NOT send a DN value when binding with the sasl choice and servers SHALL ignore any value received in this circumstance. - -Harrison Expires February 2005 [Page 33] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - - + Section 8.3.1 + - Generalized the language of this section to not refer to any specific password attribute or to refer to the directory entry as a "user" entry. + Section 11 + - Added security consideration regarding misuse of unauthenticated access. + - Added security consideration requiring access control to be applied only to authenticated users and recommending it be applied when reading sensitive information or updating directory information. + F.3. Changes for draft-ldapbis-authmeth-04 + General + - Changed references to use [RFCnnnn] format wherever possible. (References to works in progress still use [name] format.) - Various edits to correct typos and bring field names, etc. in line with specification in [Protocol] draft. + - Several issues--H.13, H.14, H.16, H.17--were resolved without requiring changes to the document. + Section 4.4.1. + - Changed ABNF grammar to use productions that are like those in the model draft. + Section 5 + - Removed sections 5.1, 5.2, and 5.4 that will be added to [Protocol]. Renumbered sections to accommodate this change. - + Section 6 - - Reviewed LDAP Association State table for completeness and - accuracy. Renumbered actions A3, A4, and A5 to be A5, A3, and A4 + + + +Harrison Expires April 2005 [Page 34] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + - Reviewed Association State table for completeness and accuracy. + Renumbered actions A3, , and A5 to be A5, A3, and A4 respectively. Re-ordered several lines in the table to ensure that actions are in ascending order (makes analyzing the table much more logical). Added action A2 to several states where it was missing and valid. Added actions A7 and A8 placeholders to states S1, S2, S4 and S5 pending resolution of issue H.28. - Section 11 - + Section 11 -Harrison Expires February 2005 [Page 34] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Modified security consideration (originally added in -03) requiring access control to be applied only to authenticated @@ -2005,13 +2469,17 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 - Section 13 + - Verified all normative references and moved informative references to a new section 14. + F.4. Changes for draft-ldapbis-authmeth-05 + General + - General editory changes to fix punctuation, spelling, line length issues, etc. - Verified and updated intra- and inter-document references @@ -2019,13 +2487,16 @@ F.4. Changes for draft-ldapbis-authmeth-05 - Document-wide review for proper usage of RFC 2119 keywords with several changes to correct improper usage. + Abstract - Updated to match current contents of documents. This was needed due to movement of material on Bind and StartTLS operations to [Protocol] in this revision. + Section 3. + - Renamed section to "Rationale for LDAP Security Mechanisms" and removed text that did not support this theme. Part of the motivation for this change was to remove the implication of the @@ -2033,266 +2504,352 @@ F.4. Changes for draft-ldapbis-authmeth-05 other text found in the section that everything in the section was a requirement + - Information from several removed paragraphs that describe deployment scenarios will be added Appendix A in the next revision of the draft. + - Paragraph beginning, " If TLS is negotiated, the client MUST discard all information..." was moved to section 5.1.7 and integrated with related material there. + + +Harrison Expires April 2005 [Page 35] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Paragraph beginning, "If a SASL security layer is negotiated..." was moved to section 4.2 + Section 4.l. + - Changed wording of first paragraph to clarify meaning. + Section 4.2. - Added paragraph from section 3 of -04 beginning, "If a SASL security layer is negotiated..." -Harrison Expires February 2005 [Page 35] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Section 4.3.3. - Renamed to "Other SASL Mechanisms" and completely rewrote the section (one sentence) to generalize the treatment of SASL mechanisms not explicitly mentioned in this document. + Section 4.4.1. + - Added paragraph beginning, "The dnAuthzID choice allows client applications..." to clarify whether DN form authorization identities have to also have a corresponding directory entry. This change was based on editor's perception of WG consensus. + - Made minor clarifying edits in the paragraph beginning, "The uAuthzID choice allows for compatibility..." + Section 5.1.1. + - Made minor clarifying edits in the last paragraph of the section. + Section 5.1.7. + - Wording from section 3 paragraph beginning " If TLS is negotiated, the client MUST discard all information..." was moved to this section and integrated with existing text. + Section 5.2. + - Changed usage of "TLS connection" to "TLS session" throughout. + - Removed empty section 5.2.1 and renumbered sections it had previously contained. + Section 8. + - Added introductory paragraph at beginning of section. + Section 8.1. + - Changed term "data privacy" to "data confidentiality" to be consistent with usage in rest of document. + Section 8.2. + +Harrison Expires April 2005 [Page 36] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + - Changed first paragraph to require implementations that implement *password-based* authentication to implement and support DIGEST-MD5 SASL authentication. + Section 11. + - First paragraph: changed "session encryption" to "session confidentiality protection" to be consistent with usage in rest of document. -Harrison Expires February 2005 [Page 36] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Appendix B. + - Began changes to incorporate information on deployment scenarios removed from section 3. + F.5. Changes for draft-ldapbis-authmeth-06 + General + - Combined Section 2 (Introduction) and Section 3 (Motivation) and moved Introduction to section 1. All following sections numbers were decremented by one as result. + - Edits to fix typos, I-D nits, etc. + - Opened several new issues in Appendix G based on feedback from WG. Some of these have been resolved. Others require further discussion. + Section 1 + - Added additional example of spoofing under threat (7). + Section 2.1 - - Changed definition of "LDAP association" and added terms, + + - Changed definition of "association" and added terms, "connection" and "TLS connection" to bring usage in line with [Protocol]. + Section 4.1.6 + - Clarified sentence stating that the client MUST NOT use derived forms of DNS names. + Section 5.1 - - Began edits to LDAP Association state table to clarify meaning - of various states and actions. + + - Began edits to association state table to clarify meaning of + various states and actions. + - Added action A9 to cover abandoned bind operation and added appropriate transitions to the state transition table to accommodate it. + + +Harrison Expires April 2005 [Page 37] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + Section 7.2 + - Replaced first paragraph to clarify that the "DIGEST-MD5" SASL mechanism is required to implement. + Section 9 + - Rewrote the section to make the advice more applicable over the long term, i.e. more "timeless." The intent of content in the original section was preserved. -Harrison Expires February 2005 [Page 37] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Section 10 + - Added a clarifying example to the consideration regarding misuse of unauthenticated access. + F.6. Changes for draft-ldapbis-authmeth-07 + General + - Updated external and internal references to accommodate changes in recent drafts. + - Opened several new issues in Appendix G based on feedback from WG. Some of these have been resolved. Others require further discussion. + Section 3 + - Rewrote much of section 3.3 to meet the SASL profile requirements of draft-ietf-sasl-rfc2222bis-xx.txt section 5. + - Changed treatement of SASL ANONYMOUS and PLAIN mechanisms to bring in line with WG consensus. + Section 4 + - Note to implementers in section 4.1.1 based on operational experience. + - Clarification on client continuing by performing a StartTLS with TLS already established in section 4.1.4. + - Moved verification of mapping of client's authentication ID to asserted authorization ID to apply only to explicit assertion. The local policy in place for implicit assertion is adequate. + Section 7 + - Removed most of section 7.2 as the information is now covered adequately via the new SASL profile in section 3.3. Added note to implementors regarding the treatment of username and realm values in DIGEST-MD5. + + +Harrison Expires April 2005 [Page 38] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Section 7.3. Minor clarifications in wording. + - Section 7.3.1. Clarification that a match of the presented value to any member of the set of stored passwords constitutes a successful authentication. + F.7. Changes for draft-ldapbis-authmeth-08 - General + General -Harrison Expires February 2005 [Page 38] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Changed usage from LDAPv3 to LDAP for usage consistency across LDAP technical specification. + - Fixed a number of usage nits for consistency and to bring doc in conformance with publication guidelines. + Abstract + - Significant cleanup and rewording of abstract based on WG feedback. + Section 2.1 + - New definition of user. + Section 3 + - Added 1.5 sentences at end of introductory paragraph indicating - the effect of the Bind op on the LDAP association. + the effect of the Bind op on the association. + Section 3.1 + - Retitled section and clarified wording + Section 3.2 + - Clarified that simple authentication choice provides three types of authentication: anonymous, unauthenticated, and simple password. + Section 3.3.3 + - New wording clarifying when negotiated security mechanisms take effect. + Section 3.3.5 + - Changed requirement to discard information about server fetched prior to SASL negotiation from MUST to SHOULD to allow for information obtained through secure mechanisms. + Section 3.3.6 + + + +Harrison Expires April 2005 [Page 39] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Simplified wording of first paragraph based on suggestion from WG. + Section 3.4 + - Minor clarifications in wording. - Section 3.4.1 - - - Minor clarifications in wording in first sentence. + Section 3.4.1 -Harrison Expires February 2005 [Page 39] - -Internet-Draft LDAP Authentication Methods 16 July 2004 + - Minor clarifications in wording in first sentence. - Explicitly called out that the DN value in the dnAuthzID form is to be matched using DN matching rules. - Called out that the uAuthzID MUST be prepared using SASLprep @@ -2300,79 +2857,104 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 - Clarified requirement on assuming global uniqueness by changing a "generally... MUST" wording to "SHOULD". + Section 4.1.1 + - Simplified wording describing conditions when StartTLS cannot be sent. - Simplified wording in note to implementers regarding race condition with outstanding LDAP operations on connection. + Section 4.1.5 + - Removed section and moved relevant text to section 4.2.2. + Section 4.1.6 + - Renumbered to 4.1.5. - Updated server identity check rules for server's name based on WG list discussion. + Section 4.1.7 + - Renumbered to 4.1.6 - Changed requirement to discard information about server fetched prior to TLS negotion from MUST to SHOULD to allow for information obtained through secure mechanisms. + Section 6.1 + - Clarified wording. - Added definition of anonymous and unauthenticated binds. + Section 10 + - Added security consideration (moved from elsewhere) discouraging use of cleartext passwords on unprotected communication channels. + Section 11 + + +Harrison Expires April 2005 [Page 40] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Added an IANA consideration to update GSSAPI service name registry to point to [Roadmap] and [Authmeth] + F.8. Changes for draft-ldapbis-authmeth-09 + General + - Updated section references within document - Changed reference tags to match other docs in LDAP TS - Used non-quoted names for all SASL mechanisms -Harrison Expires February 2005 [Page 40] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Abstract + - Inspected keyword usage and removed several improper usages. + - Removed sentence saying DIGEST-MD5 is LDAP's mandatory-to- implement mechanism. This is covered elsewhere in document. + - Moved section 5, authentication state table, of -08 draft to section 8 of -09 and completely rewrote it. + Section 1 + - Reworded sentence beginning, "It is also desirable to allow - authentication methods to carry identities based on existingù + authentication methods to carry identities based on existing, non-LDAP DN-forms..." - Clarified relationship of this document to other documents in the LDAP TS. + Section 3.3.5 + - Removed paragraph beginning,"If the client is configured to support multiple SASL mechanisms..." because the actions specified in the paragraph do not provide the protections @@ -2380,70 +2962,94 @@ Internet-Draft LDAP Authentication Methods 16 July 2004 server should allow specification of acceptable mechanisms and only allow those mechanisms to be used. + - Clarified independent behavior when TLS and SASL security layers are both in force (e.g. one being removed doesn't affect the other). + Section 3.3.6 + - Moved most of section 4.2.2, Client Assertion of Authorization Identity, to sections 3.3.6, 3.3.6.1, and 3.3.6.2. + Section 3.3.6.4 + - Moved some normative comments into text body. + Section 4.1.2 + + + +Harrison Expires April 2005 [Page 41] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + - Non success resultCode values are valid if server is *unwilling* or unable to negotiate TLS. + Section 4.2.1 + - Rewrote entire section based on WG feedback. + Section 4.2.2 - - Moved most of this section to 3.3.6 for better document flow. + - Moved most of this section to 3.3.6 for better document flow. -Harrison Expires February 2005 [Page 41] - -Internet-Draft LDAP Authentication Methods 16 July 2004 Section 4.2.3 + - Rewrote entire section based on WG feedback. + Section 5.1 + - Moved imperative language regarding unauthenticated access from security considerations to here. + Section 6 + - Added several paragraphs regarding the risks of transmitting passwords in the clear and requiring server implementations to provide a specific configuration that reduces these risks. + Section 6.2 + - Added sentence describing protections provided by DIGEST-MD5 method. - Changed DNs in exmple to be dc=example,dc=com. + Section 10 + - Updated consideration on use of cleartext passwords to include other unprotected authentication credentials - Substantial rework of consideration on misuse of unauthenticated bind. + F.9. Changes for draft-ldapbis-authmeth-10 + - Reorganized content of sections 3-9 to improve document flow and reduce redundancy. - - Resolved issue of effect of Start TLS and TLS closure on LDAP + - Resolved issue of effect of Start TLS and TLS closure on association state. - Made numerous minor wording changes based on WG feedback. - Updated list of threats for Section 1. @@ -2452,10 +3058,18 @@ F.9. Changes for draft-ldapbis-authmeth-10 - Moved authentication state table to appendix and relettered appendices. + F.10. Changes for draft-ldapbis-authmeth-11 + + +Harrison Expires April 2005 [Page 42] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + General + - Many editorial changes throughout to clarify wording and better express intent, primarily based on suggestions from WG mail list. @@ -2463,106 +3077,205 @@ F.10. Changes for draft-ldapbis-authmeth-11 document, e.g. "Anonymous Authentication Mechanism of the Simple Bind Choice". - Section 1 + Section 1 -Harrison Expires February 2005 [Page 42] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Editorial changes to add clarity. - Moved section 2 of authmeth -09 into section 1 + Section 2 + - New section outlining implementation requirements. + Section 3.1.1 + - Editorial clarification on need for following operation sequencing requirements. + Section 3.1.4 + - New section added to describe use of client certificates with StartTLS. Incorporates material moved from other sections of authmeth -09. + Section 4 - - New section added to discuss LDAP Associations. Related material - was moved from various other sections of authmeth -09 and + - New section added to discuss associations. Related material was + moved from various other sections of authmeth -09 and incorporated into this new section. + Section 5 + - Added several paragraphs regarding transmission and derivation of authentication and authorization identities using the Bind operation. + Section 8 + - Clarified rules for determining valid credentials and situations where invalidCredentials result is to be returned. + Section 14 + - Added three security considerations based on WG feedback. + Appendix A + - Simplfied state tables by removing two unnecessary actions from the actions table, and removing the current state column of the + + + +Harrison Expires April 2005 [Page 43] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + state transition table. Updated references to authmeth and [Protocol]. + F.11. Changes for draft-ldapbis-authmeth-12 + General + - Changed refererences from Start TLS to StartTLS. - Removed Appendix B: Example Deployment Scenarios - Removed Appendix H as all issues listed in the appendix are now resolved. -Harrison Expires February 2005 [Page 43] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - Section 2 + - Added implementation requirement that server implementations that SUPPORT StartTLS MUST support the TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA ciphersuite. + Section 3.1.2 + - Added wording clarifying that a client's association is unaffected if a non-success resultCode is returned in the StartTLS response. + Section 9.2 + - Final paragraph of this section details requirements for serverSaslCreds field when no challenge value is sent. + Section 10 + - Clarified language on uAuthzID usage. + Section 12 + - Moved entire section into security considerations. New section number is 12.1.1. - Reorganized security considerations by topic. - Added several security considerations based on WG feedback. + Section 13 + - Moved section to become section 3.3. + +F.12. Changes for draft-ldapbis-authmeth-13 + + + General + + + - General edits for clarity and to remove errors. + - Reworded definition of association (section 1.2) and reworked + usage of association throughout document. Current semantics: + every connection has an association with the same lifetime as + the connection, and that association passes through various + authorization states. + + +Harrison Expires April 2005 [Page 44] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + + - Made usage of data confidentiality consistent throughout + document. + + + Section 1 + - Reworded mechanisms 3 and 4 for more parallelism. + - Changed language on rationale for required mechansisms from + future to past tense. + + + Section 2 + - Clarified that implementations may support any additional + authentication mechanism, not just mechanisms associated with + simple and SASL bind choices. + + + Section 3 + - Moved paragraph explaining goals for using TLS with LDAP from + security considerations to here. + + + Section 4.3 + - Reworked text to better explain meaning of strongAuthRequired + result code when for invalidated associations. + + + Section 8 + - Clarified action when simple bind request has a DN with invalid + syntax. + + + Section 12.1 + - Added ability to configure and enforce administrative service + limits as a way to protect against denial of service attacks. + + + Section 12.2 + - Clarified that this security consideration relates to performing + client authentication during the TLS handshake and not to + subsequent SASL EXTERNAL authentication. + + + Appendix A + - Updated tables by collapsing identical states and actions. Also + added an invalidated association state and accompanying actions. + + +Added implementation requirement that server implementations + + 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 @@ -2572,31 +3285,36 @@ Intellectual Property 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 + + +Harrison Expires April 2005 [Page 45] +Internet-Draft LDAP Authentication Methods 25 October 2004 + + 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 - - -Harrison Expires February 2005 [Page 44] - -Internet-Draft LDAP Authentication Methods 16 July 2004 - this standard. Please address the information to the IETF at ietf- ipr@ietf.org. + Full Copyright Statement + 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 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE @@ -2636,12 +3354,4 @@ Full Copyright Statement - - - - - - - -Harrison Expires February 2005 [Page 45] - +Harrison Expires April 2005 [Page 46] \ No newline at end of file diff --git a/doc/drafts/draft-ietf-ldapbis-dn-xx.txt b/doc/drafts/draft-ietf-ldapbis-dn-xx.txt index 49b4a0b8d8..eb38efdbec 100644 --- a/doc/drafts/draft-ietf-ldapbis-dn-xx.txt +++ b/doc/drafts/draft-ietf-ldapbis-dn-xx.txt @@ -1,25 +1,19 @@ - - - - - - INTERNET-DRAFT Editor: Kurt D. Zeilenga Intended Category: Standard Track OpenLDAP Foundation -Expires in six months 15 February 2004 +Expires in six months 24 October 2004 Obsoletes: 2253 + LDAP: String Representation of Distinguished Names - + + Status of 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 @@ -29,21 +23,34 @@ Status of Memo . Please send editorial comments directly to the document editor . + + 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 + 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.'' + 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 - . The list of + . The list of Internet-Draft Shadow Directories can be accessed at . + Copyright (C) The Internet Society (2004). All Rights Reserved. + Please see the Full Copyright section near the end of this document for more information. @@ -52,16 +59,14 @@ Status of Memo - - - Zeilenga LDAP: Distinguished Names [Page 1] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + Abstract + The X.500 Directory uses distinguished names (DNs) as primary keys to entries in the directory. This document defines the string representation used in the Lightweight Directory Access Protocol @@ -70,19 +75,23 @@ Abstract names, while being able to represent any distinguished name. + 1. Background and Intended Usage + In X.500-based directory systems [X.500], including those accessed using the Lightweight Directory Access Protocol (LDAP) [Roadmap], distinguished names (DNs) are used to unambiguously refer to directory entries [X.501][Models]. + The structure of a DN [X.501] is described in terms of ASN.1 [X.680]. In the X.500 Directory Access Protocol [X.511] (and other ITU-defined directory protocols), DNs are encoded using the Basic Encoding Rules (BER) [X.690]. In LDAP, DNs are represented in the string form described in this document. + It is important to have a common format to be able to unambiguously represent a distinguished name. The primary goal of this specification is ease of encoding and decoding. A secondary goal is @@ -92,67 +101,84 @@ Abstract translations (such as expressing attribute type names in the local national language). + This document defines the string representation of Distinguished Names used in LDAP [Protocol][Syntaxes]. Section 2 details the RECOMMENDED algorithm for converting a DN from its ASN.1 structured representation to a string. Section 3 details how to convert a DN from a string to a ASN.1 structured representation. + While other documents may define other algorithms for converting a DN from its ASN.1 structured representation to a string, all algorithms MUST produce strings which adhere to the requirements of Section 3. + This document does not define a canonical string representation for DNs. Comparison of DNs for equality is to be performed in accordance with the distinguishedNameMatch matching rule [Syntaxes]. + This document is an integral part of the LDAP Technical Specification [Roadmap]. This document obsoletes RFC 2253. Changes since RFC 2253 + Zeilenga LDAP: Distinguished Names [Page 2] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + are summarized in Appendix B. + This specification assumes familiarity with X.500 [X.500] and the concept of Distinguished Name [X.501][Models]. + 1.1. 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]. + Character names in this document use the notation for code points and names from the Unicode Standard [Unicode]. For example, the letter "a" may be represented as either or . + Note: a glossary of terms used in Unicode can be found in [Glossary]. Information on the Unicode character encoding model can be found in [CharModel]. + 2. Converting DistinguishedName from ASN.1 to a String + X.501 [X.501] defines the ASN.1 [X.680] structure of distinguished name. The following is a variant provided for discussion purposes. + DistinguishedName ::= RDNSequence + RDNSequence ::= SEQUENCE OF RelativeDistinguishedName + RelativeDistinguishedName ::= SET SIZE (1..MAX) OF AttributeTypeAndValue + AttributeTypeAndValue ::= SEQUENCE { type AttributeType, value AttributeValue } + This section defines the RECOMMENDED algorithm for converting a distinguished name from an ASN.1 structured representation to an UTF-8 [RFC3629] encoded Unicode [Unicode] character string representation. @@ -162,46 +188,56 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 implementations. + 2.1. Converting the RDNSequence + Zeilenga LDAP: Distinguished Names [Page 3] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + If the RDNSequence is an empty sequence, the result is the empty or zero length string. + Otherwise, the output consists of the string encodings of each RelativeDistinguishedName in the RDNSequence (according to Section 2.2), starting with the last element of the sequence and moving backwards toward the first. + The encodings of adjoining RelativeDistinguishedNames are separated by a comma (',' U+002C) character. + 2.2. Converting RelativeDistinguishedName + When converting from an ASN.1 RelativeDistinguishedName to a string, the output consists of the string encodings of each AttributeTypeAndValue (according to Section 2.3), in any order. + Where there is a multi-valued RDN, the outputs from adjoining AttributeTypeAndValues are separated by a plus sign ('+' U+002B) character. + 2.3. Converting AttributeTypeAndValue + The AttributeTypeAndValue is encoded as the string representation of - the AttributeType, followed by an equals ('=' U+003D) character, + the AttributeType, followed by an equals sign ('=' U+003D) character, followed by the string representation of the AttributeValue. The encoding of the AttributeValue is given in Section 2.4. + If the AttributeType is defined to have a short name and that short name is known to be registered [REGISTRY][BCP64bis] as identifying the AttributeType, that short name, a , is used. Otherwise the @@ -209,23 +245,27 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 , of its OBJECT IDENTIFIER. The and is defined in [Models]. + Implementations are not expected to dynamically update their knowledge of registered short names. However, implementations SHOULD provide a mechanism to allow its knowledge of registered short names to be updated. + 2.4. Converting an AttributeValue from ASN.1 to a String + If the AttributeType is of the dotted-decimal form, the AttributeValue is represented by an number sign ('#' U+0023) character followed by the hexadecimal encoding of each of the octets of the BER encoding of + Zeilenga LDAP: Distinguished Names [Page 4] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + the X.500 AttributeValue. This form is also used when the syntax of @@ -235,6 +275,7 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 form may also be used in other cases, such as when a reversible string representation is desired (see Section 5.2). + Otherwise, if the AttributeValue is of a syntax which has a LDAP-specific string encoding, the value is converted first to a UTF-8 encoded Unicode string according to its syntax specification (see @@ -243,49 +284,62 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 escaping, then that string can be used as the string representation of the value. + - a space (' ' U+0020) or number sign ('#' U+0023) occurring at the beginning of the string; + - a space (' ' U+0020) character occurring at the end of the string; + - one of the characters '"', '+', ',', ';', '<', '>', or '\' (U+0022, U+002B, U+002C, U+003B, U+003C, U+003E, or U+005C respectively); + - the null (U+0000) character. + Other characters may be escaped. + Each octet of the character to be escaped is replaced by a backslash and two hex digits, which form a single octet in the code of the character. Alternatively, if and only if the character to be escaped is one of + ' ', '"', '#', '+', ',', ';', '<', '=', '>', or '\' (U+0020, U+0022, U+0023, U+002B, U+002C, U+003B, U+003C, U+003D, U+003E, U+005C respectively) + it can be prefixed by a backslash ('\' U+0005C). + Examples of the escaping mechanism are shown in Section 4. + 3. Parsing a String back to a Distinguished Name + The string representation of Distinguished Names is restricted to UTF-8 [RFC3629] encoded Unicode [Unicode] characters. The structure of this string representation is specified using the following + Zeilenga LDAP: Distinguished Names [Page 5] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + Augmented BNF [RFC2234] grammar: + distinguishedName = [ relativeDistinguishedName *( COMMA relativeDistinguishedName ) ] relativeDistinguishedName = attributeTypeAndValue @@ -294,39 +348,47 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 attributeType = descr / numericoid attributeValue = string / hexstring + ; The following characters are to be escaped when they appear ; in the value to be encoded: ESC, one of , leading ; SHARP or SPACE, trailing SPACE, and NULL. - string = [ (leadchar / pair) - [ *( stringchar / pair ) ( trailchar / pair ) ] ] + string = [ ( leadchar / pair ) [ *( stringchar / pair ) + ( trailchar / pair ) ] ] + + + leadchar = LUTF1 / UTFMB + LUTF1 = %x01-1F / %x21 / %x24-2A / %x2D-3A / + %x3D / %x3F-5B / %x5D-7F - leadchar = LUTF1 / UTFMB - LUTF1 = %x01-1F / %x21 / %x24-2A / %x2D-3A / - %x3D / %x3F-5B / %x5D-7F trailchar = TUTF1 / UTFMB - TUTF1 = %x01-1F / %x21 / %x23-2A / %x2D-3A / - %x3D / %x3F-5B / %x5D-7F + TUTF1 = %x01-1F / %x21 / %x23-2A / %x2D-3A / + %x3D / %x3F-5B / %x5D-7F + stringchar = SUTF1 / UTFMB - SUTF1 = %x01-21 / %x23-2A / %x2D-3A / - %x3D / %x3F-5B / %x5D-7F + SUTF1 = %x01-21 / %x23-2A / %x2D-3A / + %x3D / %x3F-5B / %x5D-7F + + + pair = ESC ( ESC / special / hexpair ) + special = escaped / SPACE / SHARP / EQUALS + escaped = DQUOTE / PLUS / COMMA / SEMI / LANGLE / RANGLE + hexstring = SHARP 1*hexpair + hexpair = HEX HEX - pair = ESC ( ESC / special / hexpair ) - special = escaped / SPACE / SHARP / EQUALS - escaped = DQUOTE / PLUS / COMMA / SEMI / LANGLE / RANGLE - hexstring = SHARP 1*hexpair - hexpair = HEX HEX where the productions , , , , , , , , , , , , , , are defined in [Models]. + Each , either a or a , refers to an attribute type of an attribute value assertion (AVA). The is followed by a and an . The is either in or form. + If in form, a LDAP string representation asserted value can be obtained by replacing (left-to-right, non-recursively) each appearing in the as follows: @@ -335,27 +397,33 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 + Zeilenga LDAP: Distinguished Names [Page 6] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + replace with the octet indicated by the . + If in form, a BER representation can be obtained from converting each of the to the octet indicated by the . + One or more attribute values assertions, separated by , for a relative distinguished name. + Zero or more relative distinguished names, separated by , for a distinguished name. + Implementations MUST recognize AttributeType name strings (descriptors) listed in the following table, but MAY recognize other name strings. + String X.500 AttributeType ------ -------------------------------------------- CN commonName (2.5.4.3) @@ -368,6 +436,7 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 DC domainComponent (0.9.2342.19200300.100.1.25) UID userId (0.9.2342.19200300.100.1.1) + Implementations MAY recognize other DN string representations (such as that described in RFC 1779). However, as there is no requirement that alternative DN string representations to be recognized (and, if so, @@ -375,43 +444,58 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 with Section 2 of this document. + 4. Examples + This notation is designed to be convenient for common forms of name. This section gives a few examples of distinguished names written using this notation. First is a name containing three relative distinguished names (RDNs): + UID=jsmith,DC=example,DC=net + Here is an example name containing three RDNs, in which the first RDN is multi-valued: + OU=Sales+CN=J. Smith,DC=example,DC=net + Zeilenga LDAP: Distinguished Names [Page 7] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + + + This example shows the method of escaping of a special characters + appearing in a common name: + + CN=James \"Jim\" Smith\, III,DC=example,DC=net - This example shows the method of escaping of a comma in a common name: - CN=John Smith\, III,DC=example,DC=net + The following shows the method for encoding a value which contains a + carriage return character: - An example name in which a value contains a carriage return character: CN=Before\0dAfter,DC=example,DC=net - An example name in which an RDN was of an unrecognized type. The + + In this RDN example, the type in the RDN is unrecognized, and the value is the BER encoding of an OCTET STRING containing two octets 0x48 and 0x69. - 1.3.6.1.4.1.1466.0=#04024869,DC=example,DC=com - Finally, an example of an RDN commonName value consisting of 5 - letters: + 1.3.6.1.4.1.1466.0=#04024869 + + + Finally, this example shows an RDN whose commonName value consisting + of 5 letters: + Unicode Character Code UTF-8 Escaped ------------------------------- ------ ------ -------- @@ -421,51 +505,63 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 LATIN SMALL LETTER I U+0069 0x69 i LATIN SMALL LETTER C WITH ACUTE U+0107 0xC487 \C4\87 - could be written in printable ASCII (useful for debugging purposes): + + could be encoded in printable ASCII (useful for debugging purposes) + as: + CN=Lu\C4\8Di\C4\87 + 5. Security Considerations + The following security considerations are specific to the handling of distinguished names. LDAP security considerations are discussed in [Protocol] and other documents comprising the LDAP Technical Specification [Roadmap]. + 5.1. Disclosure + Distinguished Names typically consist of descriptive information about the entries they name, which can be people, organizations, devices or other real-world objects. This frequently includes some of the following kinds of information: - - the common name of the object (i.e. a person's full name) - - an email or TCP/IP address - - its physical location (country, locality, city, street address) + Zeilenga LDAP: Distinguished Names [Page 8] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + - the common name of the object (i.e. a person's full name) + - an email or TCP/IP address + - its physical location (country, locality, city, street address) - organizational attributes (such as department name or affiliation) + Most countries have privacy laws regarding the publication of information about people. + 5.2. Use of Distinguished Names in Security Applications + The transformations of an AttributeValue value from its X.501 form to an LDAP string representation are not always reversible back to the same BER (Basic Encoding Rules) or DER (Distinguished Encoding rules) form. An example of a situation which requires the DER form of a distinguished name is the verification of an X.509 certificate. + For example, a distinguished name consisting of one RDN with one AVA, in which the type is commonName and the value is of the TeletexString choice with the letters 'Sam' would be represented in LDAP as the @@ -473,39 +569,57 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 still 'Sam' but of the PrintableString choice would have the same representation . + Applications which require the reconstruction of the DER form of the value SHOULD NOT use the string representation of attribute syntaxes when converting a distinguished name to the LDAP format. Instead, - they SHOULD use the hexadecimal form prefixed by the number sign ('#') - as described in the first paragraph of Section 2.3. + they SHOULD use the hexadecimal form prefixed by the number sign ('#' + U+0023) as described in the first paragraph of Section 2.4. + 6. Acknowledgment + This document is an update to RFC 2253, by Mark Wahl, Tim Howes, and Steve Kille. RFC 2253 was a product of the IETF ASID Working Group. + This document is a product of the IETF LDAPBIS Working Group. + 7. Document Editor's Address + Kurt D. Zeilenga OpenLDAP Foundation -8. Normative References - [X.501] International Telecommunication Union - - Telecommunication Standardization Sector, "The Directory - -- Models," X.501(1993) (also ISO/IEC 9594-2:1994). +8. References + + Zeilenga LDAP: Distinguished Names [Page 9] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + + + [[Note to the RFC Editor: please replace the citation tags used in + referencing Internet-Drafts with tags of the form RFCnnnn.]] + + + +8.1. Normative References + + + [X.501] International Telecommunication Union - + Telecommunication Standardization Sector, "The Directory + -- Models," X.501(1993) (also ISO/IEC 9594-2:1994). [X.680] International Telecommunication Union - @@ -513,14 +627,18 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 Syntax Notation One (ASN.1) - Specification of Basic Notation", X.680(1997) (also ISO/IEC 8824-1:1998). + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14 (also RFC 2119), March 1997. + [RFC2234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. - [RFC3329] Yergeau, F., "UTF-8, a transformation format of ISO - 10646", RFC 3329 (also STD 64), November 2003. + + [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO + 10646", RFC 3629 (also STD 63), November 2003. + [Unicode] The Unicode Consortium, "The Unicode Standard, Version 3.2.0" is defined by "The Unicode Standard, Version 3.0" @@ -530,38 +648,48 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 "Unicode Standard Annex #28: Unicode 3.2" (http://www.unicode.org/reports/tr28/). + [Models] Zeilenga, K. (editor), "LDAP: Directory Information Models", draft-ietf-ldapbis-models-xx.txt, a work in progress. + [Roadmap] Zeilenga, K. (editor), "LDAP: Technical Specification Road Map", draft-ietf-ldapbis-roadmap-xx.txt, a work in progress. + [Protocol] Sermersheim, J. (editor), "LDAP: The Protocol", draft-ietf-ldapbis-protocol-xx.txt, a work in progress. + [Syntaxes] Legg, S. (editor), "LDAP: Syntaxes and Matching Rules", draft-ietf-ldapbis-syntaxes-xx.txt, a work in progress. + [Schema] Dally, K. (editor), "LDAP: User Schema", draft-ietf-ldapbis-user-schema-xx.txt, a work in + + + + +Zeilenga LDAP: Distinguished Names [Page 10] +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + + progress. + [REGISTRY] IANA, Object Identifier Descriptors Registry, . -9. Informative References - - [ASCII] Coded Character Set--7-bit American Standard Code for - Information Interchange, ANSI X3.4-1986. +8.2. Informative References - -Zeilenga LDAP: Distinguished Names [Page 10] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 + [ASCII] Coded Character Set--7-bit American Standard Code for + Information Interchange, ANSI X3.4-1986. [X.500] International Telecommunication Union - @@ -569,6 +697,7 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 -- Overview of concepts, models and services," X.500(1993) (also ISO/IEC 9594-1:1994). + [X.690] International Telecommunication Union - Telecommunication Standardization Sector, "Specification of ASN.1 encoding rules: Basic Encoding Rules (BER), @@ -576,50 +705,61 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 Encoding Rules (DER)", X.690(1997) (also ISO/IEC 8825-1:1998). + [RFC2849] Good, G., "The LDAP Data Interchange Format (LDIF) - Technical Specification", RFC 2849, June 2000. - [BCP64bis] Zeilenga, K., "IANA Considerations for LDAP", draft- - ietf-ldapbis-bcp64-xx.txt, a work in progress. + + [BCP64bis] Zeilenga, K., "IANA Considerations for LDAP", + draft-ietf-ldapbis-bcp64-xx.txt, a work in progress. + [CharModel] Whistler, K. and M. Davis, "Unicode Technical Report #17, Character Encoding Model", UTR17, , August 2000. + [Glossary] The Unicode Consortium, "Unicode Glossary", . + Appendix A. Presentation Issues + This appendix is provided for informational purposes only, it is not a normative part of this specification. + The string representation described in this document is not intended to be presented to humans without translation. However, at times it may be desirable to present non-translated DN strings to users. This section discusses presentation issues associated with non-translated DN strings. Presentation of translated DN strings issues are not + + + + +Zeilenga LDAP: Distinguished Names [Page 11] +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + + discussed in this appendix. Transcoding issues are also not discussed in this appendix. + This appendix provides guidance for applications presenting DN strings to users. This section is not comprehensive, it does not discuss all presentation issues which implementors may face. + Not all user interfaces are capable of displaying the full set of Unicode characters. Some Unicode characters are not displayable. - - -Zeilenga LDAP: Distinguished Names [Page 11] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 - - It is recommended that human interfaces use the optional hex pair escaping mechanism (Section 2.3) to produce a string representation suitable for display to the user. For example, an application can @@ -627,6 +767,7 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 characters appearing in the AttributeValue's string representation (as demonstrated in the final example of Section 4). + When a DN string is displayed in free form text, it is often necessary to distinguish the DN string from surrounding text. While this is often done with white space (as demonstrated in Section 4), it is @@ -640,6 +781,7 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 be noted to the user that the wrapping '<' and '>' characters are not part of the DN string. + DN strings can be quite long. It is often desirable to line-wrap overly long DN strings in presentations. Line wrapping should be done by inserting white space after the RDN separator character or, if @@ -647,19 +789,32 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 the user that the inserted white space is not part of the DN string and is to be removed before use in LDAP. For example, + The following DN string is long: CN=Kurt D. Zeilenga,OU=Engineering,L=Redwood Shores, O=OpenLDAP Foundation,ST=California,C=US so it has been line-wrapped for readability. The extra white space is to be removed before the DN string is used in LDAP. + It is not advised to insert white space otherwise as it may not be obvious to the user which white space is part of the DN string and which white space was added for readability. + Another alternative is to use the LDAP Data Interchange Format (LDIF) + + + + +Zeilenga LDAP: Distinguished Names [Page 12] +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + + [RFC2849]. For example, + # This entry has a long DN... dn: CN=Kurt D. Zeilenga,OU=Engineering,L=Redwood Shores, O=OpenLDAP Foundation,ST=California,C=US @@ -669,23 +824,22 @@ INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 - - -Zeilenga LDAP: Distinguished Names [Page 12] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 - - Appendix B. Changes made since RFC 2253 + This appendix is provided for informational purposes only, it is not a normative part of this specification. + The following substantive changes were made to RFC 2253: - Removed IESG Note. The IESG Note has been addressed. - Replaced all references to ISO 10646-1 with [Unicode]. - Clarified (in Section 1) that this document does not define a canonical string representation. + - Clarified that Section 2 describes the RECOMMENDED encoding + algorithm and that alternative algorithms are allowed. Some + encoding options described in RFC 2253 are now treated as + alternative algorithms in this specification. - Revised specification (in Section 2) to allow short names of any registered attribute type to appear in string representations of DNs instead of being restricted to a "published table". Remove @@ -693,17 +847,34 @@ Appendix B. Changes made since RFC 2253 recognition of additional names but require recognization of those names in the published table. The table is now published in Section 3. - - Replaced specification of additional requirements for LDAPv2 - implementations which also support LDAPv3 (RFC 2253, Section 4) - with a statement (in Section 3) allowing recognition of - alternative string representations. - - Updated Section 2.3 to indicate attribute type name strings are - case insensitive. + - Removed specification of additional requirements for LDAPv2 + implementations which also support LDAPv3 (RFC 2253, Section 4) as + LDAPv2 is now Historic. + - Allow recognition of alternative string representations. - Updated Section 2.4 to allow hex pair escaping of all characters - and clarified escaping for when multiple octet UTF-8 echodings are - present. + and clarified escaping for when multiple octet UTF-8 encodings are + present. Indicated that null (U+0000) character is to be escaped. + Indicated that equals sign ('=' U+003D) character may be escaped + as '\='. - Rewrote Section 3 to use ABNF as defined in RFC 2234. - - Rewrote Section 3 ABNF to be consistent with 2.4. + - Updated the Section 3 ABNF. Changes include: + + allow AttributeType short names of length 1 (e.g., 'L'), + + use more restrictive production in AttributeTypes, + + do not require escaping of equals sign ('=' U+003D) characters, + + do not require escaping of non-leading number sign ('#' U+0023) + characters, + + allow space (' ' U+0020) to escaped as '\ ', + + + + +Zeilenga LDAP: Distinguished Names [Page 13] +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + + + + + require hex escaping of null (U+0000) characters, and + + removed LDAPv2-only constructs. - Updated Section 3 to describe how to parse elements of the grammar. - Rewrote examples. @@ -712,65 +883,65 @@ Appendix B. Changes made since RFC 2253 - Added discussion of presentation issues (Appendix A). - Added this appendix. + In addition, numerous editorial changes were made. -Intellectual Property Rights - The IETF takes no position regarding the validity or scope of any - intellectual property 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; neither does it represent that it has made any - effort to identify any such rights. Information on the IETF's - procedures with respect to rights in standards-track and +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. -Zeilenga LDAP: Distinguished Names [Page 13] - -INTERNET-DRAFT draft-ietf-ldapbis-dn-13.txt 15 Febrary 2004 + 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. - standards-related documentation can be found in BCP-11. Copies of - claims of rights made available for publication 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 implementors or users of this specification can be obtained - from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary - rights which may cover technology that may be required to practice - this standard. Please address the information to the IETF Executive - Director. + rights that may cover technology that may be required to implement + this standard. Please address the information to the IETF at + ietf-ipr@ietf.org. + Full Copyright - Copyright (C) The Internet Society (2004). 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. + 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 + "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS + OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET +Zeilenga LDAP: Distinguished Names [Page 14] +INTERNET-DRAFT draft-ietf-ldapbis-dn-15.txt 24 October 2004 + 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. @@ -783,5 +954,39 @@ Full Copyright -Zeilenga LDAP: Distinguished Names [Page 14] - + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +Zeilenga LDAP: Distinguished Names [Page 15] \ No newline at end of file diff --git a/doc/drafts/draft-ietf-ldapbis-filter-xx.txt b/doc/drafts/draft-ietf-ldapbis-filter-xx.txt index a82828c4d3..59fa2100cf 100644 --- a/doc/drafts/draft-ietf-ldapbis-filter-xx.txt +++ b/doc/drafts/draft-ietf-ldapbis-filter-xx.txt @@ -1,30 +1,40 @@ + Network Working Group M. Smith, Editor Request for Comments: DRAFT Pearl Crescent, LLC Obsoletes: RFC 2254 T. Howes -Expires: 13 August 2004 Opsware, Inc. - 13 February 2004 +Expires: 24 April 2005 Opsware, Inc. + 24 October 2004 LDAP: String Representation of Search Filters - + + +Status of this Memo -1. Status of this Memo + By submitting this Internet-Draft, each author represents that any + applicable patent or other IPR claims of which he or she is aware + have been or will be disclosed, and any of which he or she become + aware will be disclosed, in accordance with RFC 3668. - This document is an Internet-Draft and is subject to all provisions - of Section 10 of RFC2026. + This document is intended to be published as a Standards Track RFC, + replacing RFC 2254. Distribution of this memo is unlimited. + Technical discussion of this document will take place on the IETF + LDAP (v3) Revision (ldapbis) Working Group mailing list + . Please send editorial comments directly + to the editor . 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. + 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." + time. It is inappropriate to use Internet-Drafts as reference + material or to cite them other than a "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html @@ -32,19 +42,10 @@ Expires: 13 August 2004 Opsware, Inc. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html - Discussion of this document should take place on the LDAP (v3) - Revision (ldapbis) Working Group mailing list . - Copyright (C) The Internet Society (2004). All Rights Reserved. + Please see the Full Copyright section near the end of this document + for more information. -2. Abstract - - LDAP search filters are transmitted in the LDAP protocol using a - binary representation that is appropriate for use on the network. - This document defines a human-readable string representation of LDAP - search filters that is appropriate for use in LDAP URLs and in other - applications. @@ -52,33 +53,41 @@ Expires: 13 August 2004 Opsware, Inc. Smith & Howes Intended Category: Standards Track [Page 1] -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - - -3. Table of Contents - -1. Status of this Memo............................................1 -2. Abstract.......................................................1 -3. Table of Contents..............................................2 -4. Introduction...................................................2 -5. LDAP Search Filter Definition..................................2 -6. String Search Filter Definition................................4 -7. Examples.......................................................5 -8. Security Considerations........................................7 -9. Normative References...........................................7 -10. Informative References.........................................8 -11. Intellectual Property Rights...................................8 -12. Acknowledgments................................................8 -13. Authors' Addresses.............................................9 -14. Full Copyright Statement.......................................9 -15. Appendix A: Changes Since RFC 2254.............................10 -15.1. Technical Changes...........................................10 -15.2. Editorial Changes...........................................10 -16. Appendix B: Changes Since Previous Document Revision...........11 -16.1. Technical Changes...........................................12 -16.2. Editorial Changes...........................................12 - -4. Introduction +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + +Abstract + + LDAP search filters are transmitted in the LDAP protocol using a + binary representation that is appropriate for use on the network. + This document defines a human-readable string representation of LDAP + search filters that is appropriate for use in LDAP URLs and in other + applications. + +Table of Contents + + Status of this Memo............................................1 + Abstract.......................................................2 + Table of Contents..............................................2 +1. Introduction...................................................2 +2. LDAP Search Filter Definition..................................3 +3. String Search Filter Definition................................4 +4. Examples.......................................................6 +5. Security Considerations........................................7 +6. IANA Considerations............................................7 +7. Normative References...........................................7 +8. Informative References.........................................8 +9. Acknowledgments................................................8 +10. Authors' Addresses.............................................8 +11. Appendix A: Changes Since RFC 2254.............................9 +11.1. Technical Changes...........................................9 +11.2. Editorial Changes...........................................10 +12. Appendix B: Changes Since Previous Document Revision...........11 +12.1. Editorial Changes...........................................11 +13. Intellectual Property Rights...................................11 +14. Full Copyright.................................................12 + +1. Introduction The Lightweight Directory Access Protocol (LDAP) [Protocol] defines a network representation of a search filter transmitted to an LDAP @@ -89,61 +98,62 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 possible LDAP version 3 search filters, including extended match filters. - This document is an integral part of the LDAP Technical - Specification [Roadmap]. + This document is an integral part of the LDAP Technical Specification + [Roadmap]. This document replaces RFC 2254. Changes to RFC 2254 are summarized in Appendix A. + + + +Smith & Howes Intended Category: Standards Track [Page 2] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + 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]. -5. LDAP Search Filter Definition +2. LDAP Search Filter Definition An LDAPv3 search filter is defined in Section 4.5.1 of [Protocol] as follows: - - -Smith & Howes Intended Category: Standards Track [Page 2] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - - Filter ::= CHOICE { - and [0] SET SIZE (1..MAX) OF filter Filter, - or [1] SET SIZE (1..MAX) OF filter Filter, - not [2] Filter, - equalityMatch [3] AttributeValueAssertion, - substrings [4] SubstringFilter, - greaterOrEqual [5] AttributeValueAssertion, - lessOrEqual [6] AttributeValueAssertion, - present [7] AttributeDescription, - approxMatch [8] AttributeValueAssertion, - extensibleMatch [9] MatchingRuleAssertion } + and [0] SET SIZE (1..MAX) OF filter Filter, + or [1] SET SIZE (1..MAX) OF filter Filter, + not [2] Filter, + equalityMatch [3] AttributeValueAssertion, + substrings [4] SubstringFilter, + greaterOrEqual [5] AttributeValueAssertion, + lessOrEqual [6] AttributeValueAssertion, + present [7] AttributeDescription, + approxMatch [8] AttributeValueAssertion, + extensibleMatch [9] MatchingRuleAssertion } SubstringFilter ::= SEQUENCE { - type AttributeDescription, - -- initial and final can occur at most once - substrings SEQUENCE SIZE (1..MAX) OF substring CHOICE { - initial [0] AssertionValue, - any [1] AssertionValue, - final [2] AssertionValue } } + type AttributeDescription, + -- initial and final can occur at most once + substrings SEQUENCE SIZE (1..MAX) OF substring CHOICE { + initial [0] AssertionValue, + any [1] AssertionValue, + final [2] AssertionValue } } AttributeValueAssertion ::= SEQUENCE { - attributeDesc AttributeDescription, - assertionValue AssertionValue } + attributeDesc AttributeDescription, + assertionValue AssertionValue } MatchingRuleAssertion ::= SEQUENCE { - matchingRule [1] MatchingRuleId OPTIONAL, - type [2] AttributeDescription OPTIONAL, - matchValue [3] AssertionValue, - dnAttributes [4] BOOLEAN DEFAULT FALSE } + matchingRule [1] MatchingRuleId OPTIONAL, + type [2] AttributeDescription OPTIONAL, + matchValue [3] AssertionValue, + dnAttributes [4] BOOLEAN DEFAULT FALSE } AttributeDescription ::= LDAPString - -- Constrained to - -- [Models] + -- Constrained to + -- [Models] AttributeValue ::= OCTET STRING @@ -151,32 +161,31 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 AssertionValue ::= OCTET STRING - LDAPString ::= OCTET STRING -- UTF-8 encoded, - -- [ISO10646] characters - - The AttributeDescription is a string representation of the attribute - description and is defined in [Protocol]. The AttributeValue and - AssertionValue OCTET STRING have the form defined in [Syntaxes]. The - Filter is encoded for transmission over a network using the Basic - Encoding Rules defined in [X.690], with simplifications described in - Smith & Howes Intended Category: Standards Track [Page 3] -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 - [Protocol]. + LDAPString ::= OCTET STRING -- UTF-8 encoded, + -- [Unicode] characters -6. String Search Filter Definition + The AttributeDescription is a string representation of the attribute + description and is defined in [Protocol]. The AttributeValue and + AssertionValue OCTET STRING have the form defined in [Syntaxes]. The + Filter is encoded for transmission over a network using the Basic + Encoding Rules (BER) defined in [X.690], with simplifications + described in [Protocol]. + +3. String Search Filter Definition The string representation of an LDAP search filter is a string of - UTF-8[RFC3629] encoded ISO 10646-1 characters that is defined by the - following grammar, following the ABNF notation defined in [RFC2234]. - The productions used that are not defined here are defined in section - 1.4 (Common ABNF Productions) of [Models] unless otherwise noted. - The filter format uses a prefix notation. + UTF-8 [RFC3629] encoded Unicode characters [Unicode] that is defined + by the following grammar, following the ABNF notation defined in + [RFC2234]. The productions used that are not defined here are + defined in section 1.4 (Common ABNF Productions) of [Models] unless + otherwise noted. The filter format uses a prefix notation. filter = LPAREN filtercomp RPAREN filtercomp = and / or / not / item @@ -186,13 +195,15 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 filterlist = 1*filter item = simple / present / substring / extensible simple = attr filtertype assertionvalue - filtertype = equal / approx / greater / less + filtertype = equal / approx / greaterorequal / lessorequal equal = EQUALS approx = TILDE EQUALS - greater = RANGLE EQUALS - less = LANGLE EQUALS - extensible = attr [dnattrs] [matchingrule] COLON EQUALS assertionvalue - / [dnattrs] matchingrule COLON EQUALS assertionvalue + greaterorequal = RANGLE EQUALS + lessorequal = LANGLE EQUALS + extensible = attr [dnattrs] + [matchingrule] COLON EQUALS assertionvalue + / [dnattrs] + matchingrule COLON EQUALS assertionvalue / COLON EQUALS assertionvalue present = attr EQUALS ASTERISK substring = attr EQUALS [initial] any [final] @@ -205,8 +216,16 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 dnattrs = COLON "dn" matchingrule = COLON oid assertionvalue = valueencoding - ; The rule is used to encode an - ; from Section 4.1.6 of [Protocol]. + + + +Smith & Howes Intended Category: Standards Track [Page 4] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + + ; The rule is used to encode an + ; from Section 4.1.6 of [Protocol]. valueencoding = 0*(normal / escaped) normal = UTF1SUBSET / UTFMB escaped = ESC HEX HEX @@ -215,14 +234,6 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 ; RPAREN, ASTERISK, and ESC. EXCLAMATION = %x21 ; exclamation mark ("!") AMPERSAND = %x26 ; ampersand (or AND symbol) ("&") - - - -Smith & Howes Intended Category: Standards Track [Page 4] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - - ASTERISK = %x2A ; asterisk ("*") COLON = %x3A ; colon (":") VERTBAR = %x7C ; vertical bar (or pipe) ("|") @@ -261,24 +272,24 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 are not valid UTF-8 strings. This is necessary because RFC 2254 did not clearly define the term "string representation" (and in particular did not mention that the string representation of an LDAP - search filter is a string of UTF-8 encoded ISO 10646-1 characters). -7. Examples - This section gives a few examples of search filters written using - this notation. - (cn=Babs Jensen) - (!(cn=Tim Howes)) - (&(objectClass=Person)(|(sn=Jensen)(cn=Babs J*))) +Smith & Howes Intended Category: Standards Track [Page 5] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + search filter is a string of UTF-8 encoded Unicode characters). -Smith & Howes Intended Category: Standards Track [Page 5] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 +4. Examples + This section gives a few examples of search filters written using + this notation. + (cn=Babs Jensen) + (!(cn=Tim Howes)) + (&(objectClass=Person)(|(sn=Jensen)(cn=Babs J*))) (o=univ*of*mich*) (seeAlso=) @@ -317,6 +328,14 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 The following examples illustrate the use of the escaping mechanism. (o=Parens R Us \28for all your parenthetical needs\29) + + + +Smith & Howes Intended Category: Standards Track [Page 6] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + (cn=*\2A*) (filename=C:\5cMyFile) (bin=\00\00\00\04) @@ -327,14 +346,6 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 represent parenthesis characters. The second shows how to represent a "*" in an assertion value, preventing it from being interpreted as a substring indicator. The third illustrates the escaping of the - - - -Smith & Howes Intended Category: Standards Track [Page 6] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - - backslash character. The fourth example shows a filter searching for the four-byte value @@ -347,7 +358,7 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 The sixth and final example demonstrates assertion of a BER encoded value. -8. Security Considerations +5. Security Considerations This memo describes a string representation of LDAP search filters. While the representation itself has no known security implications, @@ -358,21 +369,29 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 Please refer to the Security Considerations sections of [Protocol] and [AuthMeth] for more information. -9. Normative References +6. IANA Considerations -[AuthMeth] Harrison, R. (editor), "LDAP: Authentication Methods and - Connection Level Security Mechanisms", draft-ietf-ldapbis- - authmeth-xx.txt, a work in progress. + This document has no actions for IANA. -[ISO10646] Universal Multiple-Octet Coded Character Set (UCS) - - Architecture and Basic Multilingual Plane, ISO/IEC 10646-1, - 1993. +7. Normative References + +[AuthMeth] Harrison, R. (editor), "LDAP: Authentication Methods and + Connection Level Security Mechanisms", + draft-ietf-ldapbis-authmeth-xx.txt, a work in progress. [Models] Zeilenga, K. (editor), "LDAP: Directory Information Models", draft-ietf-ldapbis-models-xx.txt, a work in progress. [Protocol] draft-ietf-ldapbis-protocol-xx.txt, a work in progress. + + + +Smith & Howes Intended Category: Standards Track [Page 7] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14 (also RFC 2119), March 1997. @@ -382,52 +401,28 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO 10646", RFC 3629, November 2003. - - - - -Smith & Howes Intended Category: Standards Track [Page 7] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - - [Roadmap] Zeilenga, K. (editor), "LDAP: Technical Specification Road Map", draft-ietf-ldapbis-roadmap-xx.txt, a work in progress. -[Syntaxes] Dally, K. (editor), "LDAP: Syntaxes", draft-ietf-ldapbis- - syntaxes-xx.txt, a work in progress. +[Syntaxes] Dally, K. (editor), "LDAP: Syntaxes", + draft-ietf-ldapbis-syntaxes-xx.txt, a work in progress. + +[Unicode] The Unicode Consortium, "The Unicode Standard, Version + 3.2.0" is defined by "The Unicode Standard, Version 3.0" + (Reading, MA, Addison-Wesley, 2000. ISBN 0-201-61633-5), as + amended by the "Unicode Standard Annex #27: Unicode 3.1" + (http://www.unicode.org/reports/tr27/) and by the "Unicode + Standard Annex #28: Unicode 3.2." [X.690] Specification of ASN.1 encoding rules: Basic, Canonical, and Distinguished Encoding Rules, ITU-T Recommendation X.690, 1994. -10. Informative References +8. Informative References None. -11. Intellectual Property Rights - - The IETF takes no position regarding the validity or scope of any - intellectual property 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; neither does it represent that it - has made any effort to identify any such rights. Information on the - IETF's procedures with respect to rights in standards-track and - standards-related documentation can be found in BCP-11. Copies of - claims of rights made available for publication 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 implementors or users of this specification can - be obtained from the IETF Secretariat. - - The IETF invites any interested party to bring to its attention any - copyrights, patents or patent applications, or other proprietary - rights which may cover technology that may be required to practice - this standard. Please address the information to the IETF Executive - Director. - -12. Acknowledgments +9. Acknowledgments This document replaces RFC 2254 by Tim Howes. Changes included in this revised specification are based upon discussions among the @@ -437,26 +432,25 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 acknowledged. +10. Authors' Addresses - + Mark Smith, Editor + Pearl Crescent, LLC + 447 Marlpool Dr. + Saline, MI 48176 + USA + +1 734 944-2856 Smith & Howes Intended Category: Standards Track [Page 8] -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 -13. Authors' Addresses - Mark Smith, Editor - Pearl Crescent, LLC - 447 Marlpool Dr. - Saline, MI 48176 - USA - +1 734 944-2856 mcs@pearlcrescent.com + Tim Howes Opsware, Inc. 599 N. Mathilda Ave. @@ -465,53 +459,17 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 +1 408 744-7509 howes@opsware.com -14. Full Copyright Statement - - Copyright (C) The Internet Society (2004). 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. - - - - - - -Smith & Howes Intended Category: Standards Track [Page 9] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - +11. Appendix A: Changes Since RFC 2254 -15. Appendix A: Changes Since RFC 2254 +11.1. Technical Changes -15.1. Technical Changes + Replaced [ISO 10646] reference with [Unicode]. The following technical changes were made to the contents of the "String Search Filter Definition" section: Added statement that the string representation is a string of UTF-8 - encoded ISO 10646-1 characters. + encoded Unicode characters. Revised all of the ABNF to use common productions from [Models]. @@ -523,6 +481,9 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 precisely reference productions from the [Models] and [Protocol] documents. + "String Search Filter Definition" section: replaced "greater" and + "less" with "greaterorequal" and "lessorequal" to avoid confusion. + Introduced the "valueencoding" and associated "normal" and "escaped" rules to reduce the dependence on descriptive text. The "normal" production restricts filter strings to valid UTF-8 sequences. @@ -534,7 +495,16 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 of a clear definition of "string representation." -15.2. Editorial Changes + + + + +Smith & Howes Intended Category: Standards Track [Page 9] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + +11.2. Editorial Changes Changed document title to include "LDAP:" prefix. @@ -544,21 +514,13 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 Header and "Authors' Addresses" sections: added Mark Smith as the document editor and updated affiliation and contact information. - "Table of Contents" and "Intellectual Property Rights" sections: - added. + "Table of Contents", "IANA Considerations", and "Intellectual + Property Rights" sections: added. Copyright: updated per latest IETF guidelines. "Abstract" section: separated from introductory material. - - - -Smith & Howes Intended Category: Standards Track [Page 10] - -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 - - "Introduction" section: new section; separated from the Abstract. Updated second paragraph to indicate that RFC 2254 is replaced by this document (instead of RFC 1960). Added reference to the [Roadmap] @@ -585,10 +547,19 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 "Normative References" section: renamed from "References" per new RFC guidelines. Changed from [1] style to [Protocol] style throughout the - document. Added entries for [ISO10646], [RFC2119], [AuthMeth], + document. Added entries for [Unicode], [RFC2119], [AuthMeth], [Models], and [Roadmap] and updated the UTF-8 reference. Replaced RFC 822 reference with a reference to RFC 2234. + + + + +Smith & Howes Intended Category: Standards Track [Page 10] + +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 + + "Informative References" section: added for clarity. "Acknowledgments" section: added. @@ -599,54 +570,84 @@ INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 added. -16. Appendix B: Changes Since Previous Document Revision +12. Appendix B: Changes Since Previous Document Revision This appendix lists all changes relative to the previously published - revision, draft-ietf-ldapbis-filter-05.txt. Note that when + revision, draft-ietf-ldapbis-filter-07.txt. Note that when appropriate these changes are also included in Appendix A, but are also included here for the benefit of the people who have already - reviewed draft-ietf-ldapbis-filter-05.txt. This section will be + reviewed draft-ietf-ldapbis-filter-07.txt. This section will be removed before this document is published as an RFC. +12.1. Editorial Changes + + "Status of this Memo" section: replaced RFC 3668 (IPR) boilerplate + paragraph with the version that says "each author" instead of "I." + + "Status of this Memo" section: added 2 paragraphs that were + accidently removed from the -07 revision (one begins with "The list + of current Internet-Drafts..." and the other begins with "The list of + Internet-Draft Shadow Directories...." + + +13. 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. + + Smith & Howes Intended Category: Standards Track [Page 11] -INTERNET-DRAFT LDAP: String Repres. of Search Filters 13 February 2004 +INTERNET-DRAFT LDAP: String Repres. of Search Filters 24 October 2004 -16.1. Technical Changes + 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 + ietf-ipr@ietf.org. - None. +14. 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 + "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. + + +This Internet Draft expires on 24 April 2005. -16.2. Editorial Changes - "LDAP Search Filter Definition" section: changed the LDAPv3 search - filter ABNF so it matches that used in the latest revision of - [Protocol] and removed the following redundant descriptive text: - "where the LDAPString above is limited to the UTF-8 encoding [UTF-8] - of the ISO 10646 character set [ISO10646]." - "String Search Filter Definition" section: Corrected section - reference to [Models] and replaced this sentence: "Implementations - SHOULD accept as input a string that includes invalid UTF-8 octet - sequences." with the following: "Implementations SHOULD accept as - input strings that are not valid UTF-8 strings." - "Examples" section: Corrected the description of this example: - (sn:dn:2.4.6.8.10:=Barney Rubble). - "Normative References" section: changed UTF-8 reference to point to - RFC 3629, replaced [ASN.1] with [X.690] for consistency, and indented - the reference descriptions to enhance readability. - Authors' Addresses section: New contact information for Mark Smith. - Updated the copyright year to 2004. -This Internet Draft expires on 13 August 2004. diff --git a/doc/drafts/draft-ietf-ldapbis-models-xx.txt b/doc/drafts/draft-ietf-ldapbis-models-xx.txt index a6fb726a06..7f8a98bd28 100644 --- a/doc/drafts/draft-ietf-ldapbis-models-xx.txt +++ b/doc/drafts/draft-ietf-ldapbis-models-xx.txt @@ -1,25 +1,19 @@ - - - - - - INTERNET-DRAFT Editor: Kurt D. Zeilenga Intended Category: Standard Track OpenLDAP Foundation -Expires in six months 15 February 2004 +Expires in six months 24 October 2004 Obsoletes: RFC 2251, RFC 2252, RFC 2256 + LDAP: Directory Information Models - + + 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 published as a Standard Track RFC. Distribution of this memo is unlimited. Technical discussion of this @@ -27,44 +21,64 @@ Status of this Memo mailing list . Please send editorial comments directly to the editor . + + 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 + 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.'' + 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 - . The list of + . The list of Internet-Draft Shadow Directories can be accessed at . + Copyright (C) The Internet Society (2004). All Rights Reserved. + Please see the Full Copyright section near the end of this document for more information. + + + + + + +Zeilenga LDAP Models [Page 1] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + Abstract + The Lightweight Directory Access Protocol (LDAP) is an Internet protocol for accessing distributed directory services which act in accordance with X.500 data and service models. This document describes the X.500 Directory Information Models, as used in LDAP. - -Zeilenga LDAP Models [Page 1] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 - - Table of Contents + Status of this Memo 1 - Abstract - Table of Contents 2 + Abstract 2 + Table of Contents 1. Introduction 3 1.1. Relationship to Other LDAP Specifications 1.2. Relationship to X.501 4 @@ -72,56 +86,60 @@ Table of Contents 1.4. Common ABNF Productions 2. Model of Directory User Information 6 2.1. The Directory Information Tree 7 - 2.2. Naming of Entries - 2.3. Structure of an Entry 8 + 2.2. Structure of an Entry + 2.3. Naming of Entries 8 2.4. Object Classes 9 - 2.5. Attribute Descriptions 11 + 2.5. Attribute Descriptions 12 2.6. Alias Entries 15 3. Directory Administrative and Operational Information 17 3.1. Subtrees 3.2. Subentries - 3.3. The 'objectClass' attribute - 3.4. Operational attributes 18 - 4. Directory Schema 21 - 4.1. Schema Definitions 22 - 4.2. Subschema Subentries 31 + 3.3. The 'objectClass' attribute 18 + 3.4. Operational attributes 19 + 4. Directory Schema 20 + 4.1. Schema Definitions 23 + 4.2. Subschema Subentries 30 4.3. 'extensibleObject' 35 4.4. Subschema Discovery - 5. DSA (Server) Informational Model - 5.1. Server-specific Data Requirements 36 + 5. DSA (Server) Informational Model 36 + 5.1. Server-specific Data Requirements 6. Other Considerations 39 - 6.1. Preservation of User Information - 6.2. Short Names 40 - 6.3. Cache and Shadowing + 6.1. Preservation of User Information 40 + 6.2. Short Names + 6.3. Cache and Shadowing 41 7. Implementation Guidelines 7.1. Server Guidelines - 7.2. Client Guidelines 41 - 8. Security Considerations - 9. IANA Considerations 42 + 7.2. Client Guidelines + 8. Security Considerations 42 + 9. IANA Considerations 10. Acknowledgments 43 11. Editor's Address - 12. References - 12.1. Normative References - 12.2. Informative References 45 - Appendix A. Changes - Intellectual Property Rights 49 - Full Copyright - + 12. References 44 Zeilenga LDAP Models [Page 2] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + + 12.1. Normative References + 12.2. Informative References 45 + Appendix A. Changes + Intellectual Property Rights 50 + Full Copyright + 1. Introduction + This document discusses the X.500 Directory Information Models [X.501], as used by the Lightweight Directory Access Protocol (LDAP) [Roadmap]. + The Directory is "a collection of open systems cooperating to provide directory services" [X.500]. The information held in the Directory is collectively known as the Directory Information Base (DIB). A @@ -131,103 +149,126 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 servers (or Directory System Agents (DSA)). A server holds a fragment of the DIB. + The DIB contains two classes of information: + 1) user information (e.g., information provided and administrated by users). Section 2 describes the Model of User Information. + 2) administrative and operational information (e.g., information used to administer and/or operate the directory). Section 3 describes the model of Directory Administrative and Operational Information. + These two models, referred to as the generic Directory Information Models, describe how information is represented in the Directory. These generic models provide a framework for other information models. Section 4 discusses the subschema information model and subschema discovery. Section 5 discusses the DSA (Server) Informational Model. + Other X.500 information models, such as access control distribution knowledge, and replication knowledge information models, may be adapted for use in LDAP. Specification of how these models apply to LDAP is left to future documents. + 1.1. Relationship to Other LDAP Specifications + This document is a integral part of the LDAP technical specification [Roadmap] which obsoletes the previously defined LDAP technical + + + + +Zeilenga LDAP Models [Page 3] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + specification, RFC 3377, in its entirety. + This document obsoletes RFC 2251 sections 3.2 and 3.4, as well as portions of sections 4 and 6. Appendix A.1 summaries changes to these sections. The remainder of RFC 2251 is obsoleted by the [Protocol], [AuthMeth], and [Roadmap] documents. - - -Zeilenga LDAP Models [Page 3] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 - - This document obsoletes RFC 2252 sections 4, 5 and 7. Appendix A.2 summaries changes to these sections. The remainder of RFC 2252 is obsoleted by [Syntaxes]. + This document obsoletes RFC 2256 sections 5.1, 5.2, 7.1 and 7.2. Appendix A.3 summarizes changes to these sections. The remainder of RFC 2256 is obsoleted by [Schema] and [Syntaxes]. + 1.2. Relationship to X.501 + This document includes material, with and without adaptation, from [X.501]. The material in this document takes precedence over that in [X.501]. + 1.3. 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]. + Schema definitions are provided using LDAP description formats (as defined in Section 4.1). Definitions provided here are formatted (line wrapped) for readability. Matching rules and LDAP syntaxes referenced in these definitions are specified in [Syntaxes]. + 1.4. Common ABNF Productions + A number of syntaxes in this document are described using Augmented Backus-Naur Form (ABNF) [RFC2234]. These syntaxes (as well as a number of syntaxes defined in other documents) rely on the following common productions: + keystring = leadkeychar *keychar leadkeychar = ALPHA keychar = ALPHA / DIGIT / HYPHEN number = DIGIT / ( LDIGIT 1*DIGIT ) - ALPHA = UALPHA / %x61-7A ; "A"-"Z" / "a"-"z" - UALPHA = %x41-5A ; "A"-"Z" + + ALPHA = %x41-5A / %x61-7A ; "A"-"Z" / "a"-"z" + + + + +Zeilenga LDAP Models [Page 4] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + DIGIT = %x30 / LDIGIT ; "0"-"9" LDIGIT = %x31-39 ; "1"-"9" HEX = DIGIT / %x41-46 / %x61-66 ; "0"-"9" / "A"-"F" / "a"-"f" + SP = 1*SPACE ; one or more " " WSP = 0*SPACE ; zero or more " " - -Zeilenga LDAP Models [Page 4] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 - - NULL = %x00 ; null (0) SPACE = %x20 ; space (" ") DQUOTE = %x22 ; quote (""") @@ -249,7 +290,8 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 LCURLY = %x7B ; left curly brace "{" RCURLY = %x7D ; right curly brace "}" - ; Any UTF-8 [UTF-8] encoded UCS [ISO10646] character + + ; Any UTF-8 [UTF-8] encoded Unicode [Unicode] character UTF8 = UTF1 / UTFMB UTFMB = UTF2 / UTF3 / UTF4 UTF0 = %x80-BF @@ -260,32 +302,41 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 UTF4 = %xF0 %x90-BF 2(UTF0) / %xF1-F3 3(UTF0) / %xF4 %x80-8F 2(UTF0) - OCTET = %x00-FF ; Any octet - Object identifiers (OIDs) [X.680] are represented in LDAP using a dot- - decimal format conforming to the ABNF: + OCTET = %x00-FF ; Any octet (8-bit data unit) + + + Object identifiers (OIDs) [X.680] are represented in LDAP using a + dot-decimal format conforming to the ABNF: + numericoid = number 1*( DOT number ) + Short names, also known as descriptors, are used as more readable aliases for object identifiers. Short names are case insensitive and - conform to the ABNF: - descr = keystring - Where either an object identifier or a short name may be specified, - the following production is used: +Zeilenga LDAP Models [Page 5] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 -Zeilenga LDAP Models [Page 5] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 + + conform to the ABNF: + + + descr = keystring + + + Where either an object identifier or a short name may be specified, + the following production is used: oid = descr / numericoid + While the form is generally preferred when the usage is restricted to short names referring to object identifiers which identify like kinds of objects (e.g., attribute type descriptions, @@ -294,20 +345,26 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 identify multiple kinds of objects or when an unambiguous short name (descriptor) is not available. + Implementations SHOULD treat short names (descriptors) used in an - unambiguous manner (as discussed above) as unrecognized. + ambiguous manner (as discussed above) as unrecognized. + Short Names (descriptors) are discussed further in Section 6.2. + 2. Model of Directory User Information + As [X.501] states: + The purpose of the Directory is to hold, and provide access to, information about objects of interest (objects) in some 'world'. An object can be anything which is identifiable (can be named). + An object class is an identified family of objects, or conceivable objects, which share certain characteristics. Every object belongs to at least one class. An object class may be a subclass of other @@ -316,90 +373,163 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 the superclasses. There may be subclasses of subclasses, etc., to an arbitrary depth. + A directory entry, a named collection of information, is the basic unit of information held in the Directory. There are multiple kinds of directory entries. + An object entry represents a particular object. An alias entry provides alternative naming. A subentry holds administrative and/or operational information. + The set of entries representing the DIB are organized hierarchically - in a tree structure known as the Directory Information Tree (DIT). - Section 2.1 describes the Directory Information Tree - Section 2.2 discusses naming of entries. - Section 2.3 discusses the structure of entries. - Section 2.4 discusses object classes. - Section 2.5 discusses attribute descriptions. Zeilenga LDAP Models [Page 6] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + in a tree structure known as the Directory Information Tree (DIT). + + + Section 2.1 describes the Directory Information Tree + Section 2.2 discusses the structure of entries. + Section 2.3 discusses naming of entries. + Section 2.4 discusses object classes. + Section 2.5 discusses attribute descriptions. Section 2.6 discusses alias entries. + 2.1. The Directory Information Tree + As noted above, the DIB is composed of a set of entries organized hierarchically in a tree structure known as the Directory Information Tree (DIT). Specifically, a tree where vertices are the entries. + The arcs between vertices define relations between entries. If an arc exists from X to Y, then the entry at X is the immediate superior of Y and Y is the immediate subordinate of X. An entry's superiors are the entry's immediate superior and its superiors. An entry's subordinates are all of its immediate subordinates and their subordinates. + Similarly, the superior/subordinate relationship between object entries can be used to derive a relation between the objects they represent. DIT structure rules can be used to govern relationships between objects. + Note: An entry's immediate superior is also known as the entry's parent and an entry's immediate subordinate is also known as the entry's child. Entries which have the same parent are known as siblings. -2.2. Naming of Entries -2.2.1. Relative Distinguished Names +2.2. Structure of an Entry + + + An entry consists of a set of attributes which hold information about + the object which the entry represents. Some attributes represent user + information and are called user attributes. Other attributes + represent operational and/or administrative information and are called + operational attributes. + + + An attribute is an attribute description (a type and zero or more + options) with one or more associated values. An attribute is often + referred to by its attribute description. For example, the + 'givenName' attribute is the attribute which consists of the attribute + description 'givenName' (the 'givenName' attribute type [Schema] and + zero options) and one or more associated values. + + + + + +Zeilenga LDAP Models [Page 7] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + + The attribute type governs whether the attribute can have multiple + values, the syntax and matching rules used to construct and compare + values of that attribute, and other functions. Options indicate + subtypes and other functions. + + + Attribute values conform to the defined syntax of the attribute type. + + + No two values of an attribute may be equivalent. Two values are + considered equivalent only if they would match according to the + equality matching rule of the attribute type. If the attribute type + is defined with no equality matching rule, two values are equivalent + if and only if they are identical. (See 2.5.1 for other + restrictions.) + + + For example, a 'givenName' attribute can have more than one value, + they must be Directory Strings, and they are case insensitive. A + 'givenName' attribute cannot hold both "John" and "JOHN" as these are + equivalent values per the equality matching rule of the attribute + type. + + + When an attribute is used for naming of the entry, one and only one + value of the attribute is used in forming the Relative Distinguished + Name. This value is known as a distinguished value. + + + +2.3. Naming of Entries + + +2.3.1. Relative Distinguished Names + Each entry is named relative to its immediate superior. This relative name, known as its Relative Distinguished Name (RDN) [X.501], is composed of an unordered set of one or more attribute value assertions (AVA) consisting of an attribute description with zero options and an - attribute value. These AVAs are chosen from the attributes of the - entry. + attribute value. These AVAs are chosen to match attribute values + (each a distinguished value) of the entry. + An entry's relative distinguished name must be unique among all immediate subordinates of the entry's immediate superior (i.e., all siblings). + The following are examples of string representations of RDNs [LDAPDN]: + UID=12345 OU=Engineering CN=Kurt Zeilenga+L=Redwood Shores + The last is an example of a multi-valued RDN. That is, an RDN + composed of multiple AVAs. -Zeilenga LDAP Models [Page 7] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 + +Zeilenga LDAP Models [Page 8] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 - composed of multiple AVAs. +2.3.2. Distinguished Names -2.2.2. Distinguished Names An entry's fully qualified name, known as its Distinguished Name (DN) [X.501], is the concatenation of its RDN and its immediate superior's @@ -407,81 +537,53 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 tree. The following are examples of string representations of DNs [LDAPDN]: + UID=nobody@example.com,DC=example,DC=com CN=John Smith,OU=Sales,O=ACME Limited,L=Moab,ST=Utah,C=US -2.2.3. Alias Names + +2.3.3. Alias Names + An alias, or alias name, is "an name for an object, provided by the use of alias entries" [X.501]. Alias entries are described in Section 2.6. -2.3. Structure of an Entry - - An entry consists of a set of attributes which hold information about - the object which the entry represents. Some attributes represent user - information and are called user attributes. Other attributes - represent operational and/or administrative information and are called - operational attributes. - - An attribute is an attribute description (a type and zero or more - options) with one or more associated values. An attribute is often - referred to by its attribute description. For example, the - 'givenName' attribute is the attribute which consists of the attribute - description 'givenName' (the 'givenName' attribute type [Schema] and - zero options) and one or more associated values. - - The attribute type governs whether the attribute can have multiple - values, the syntax and matching rules used to construct and compare - values of that attribute, and other functions. Options indicate - subtypes and other functions. No two values of an attribute may be - equivalent. - - Two values are considered equivalent if they would match according to - the equality matching rule of the attribute type. If the attribute - type is defined with no equality matching rule, two values are - equivalent if and only if they are identical. - - - - -Zeilenga LDAP Models [Page 8] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 - - - For example, a 'givenName' attribute can have can have more than one - value, they must be Directory Strings, and they are case insensitive. - A 'givenName' attribute cannot hold both "John" and "JOHN" as these - are equivalent values per the equality matching rule of the attribute - type. - 2.4. Object Classes + An object class is "an identified family of objects (or conceivable objects) which share certain characteristics" [X.501]. + As defined in [X.501]: + Object classes are used in the Directory for a number of purposes: + - describing and categorising objects and the entries that correspond to these objects; + - where appropriate, controlling the operation of the Directory; + - regulating, in conjunction with DIT structure rule specifications, the position of entries in the DIT; + - regulating, in conjunction with DIT content rule specifications, the attributes that are contained in entries; + - identifying classes of entry that are to be associated with a particular policy by the appropriate administrative authority. + An object class (a subclass) may be derived from an object class (its direct superclass) which is itself derived from an even more generic object class. For structural object classes, this process @@ -489,10 +591,19 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 2.4.1). An ordered set of superclasses up to the most superior object class of an object class is its superclass chain. + + + +Zeilenga LDAP Models [Page 9] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + An object class may be derived from two or more direct superclasses (superclasses not part of the same superclass chain). This feature of subclassing is termed multiple inheritance. + Each object class identifies the set of attributes required to be present in entries belonging to the class and the set of attributes allowed to be present in entries belonging to the class. As an entry @@ -500,207 +611,275 @@ INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 can be said that an object class inherits the sets of allowed and required attributes from its superclasses. A subclass can identify an attribute allowed by its superclass as being required. If an - - - -Zeilenga LDAP Models [Page 9] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 - - attribute is a member of both sets, it is required to be present. + Each object class is defined to be one of three kinds of object classes: Abstract, Structural, or Auxiliary. + Each object class is identified by an object identifier (OID) and, optionally, one or more short names (descriptors). + 2.4.1. Abstract Object Classes + An abstract object class, as the name implies, provides a base of characteristics from which other object classes can be defined to inherit from. An entry cannot belong to an abstract object class unless it belongs to a structural or auxiliary class which inherits from that abstract class. + Abstract object classes can not derive from structural nor auxiliary object classes. + All structural object classes derive (directly or indirectly) from the 'top' abstract object class. Auxiliary object classes do not necessarily derive from 'top'. + The following is the object class definition (see Section 4.1.1) for the 'top' object class: + ( 2.5.6.0 NAME 'top' ABSTRACT MUST objectClass ) + All entries belong to the 'top' abstract object class. + 2.4.2. Structural Object Classes + As stated in [X.501]: + An object class defined for use in the structural specification of + + + + +Zeilenga LDAP Models [Page 10] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + the DIT is termed a structural object class. Structural object classes are used in the definition of the structure of the names of the objects for compliant entries. + An object or alias entry is characterised by precisely one structural object class superclass chain which has a single structural object class as the most subordinate object class. This structural object class is referred to as the structural object class of the entry. - Structural object classes are related to associated entries: - - -Zeilenga LDAP Models [Page 10] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 + Structural object classes are related to associated entries: - an entry conforming to a structural object class shall represent the real-world object constrained by the object class; + - DIT structure rules only refer to structural object classes; the structural object class of an entry is used to specify the position of the entry in the DIT; + - the structural object class of an entry is used, along with an associated DIT content rule, to control the content of an entry. + The structural object class of an entry shall not be changed. + Each structural object class is a (direct or indirect) subclass of the 'top' abstract object class. + Structural object classes cannot subclass auxiliary object classes. + Each entry is said to belong to its structural object class as well as all classes in its structural object class's superclass chain. + 2.4.3. Auxiliary Object Classes - Auxiliary object classes are used augment the characteristics of + + Auxiliary object classes are used to augment the characteristics of entries. They are commonly used to augment the sets of attributes required and allowed to be present in an entry. They can be used to describe entries or classes of entries. + Auxiliary object classes cannot subclass structural object classes. + An entry can belong to any subset of the set of auxiliary object classes allowed by the DIT content rule associated with the structural object class of the entry. If no DIT content rule is associated with the structural object class of the entry, the entry cannot belong to + + + + +Zeilenga LDAP Models [Page 11] +INTERNET-DRAFT draft-ietf-ldapbis-models-12 24 October 2004 + + + any auxiliary object class. + The set of auxiliary object classes which an entry belongs to can change over time. + 2.5. Attribute Descriptions + An attribute description is composed of an attribute type (see Section 2.5.1) and a set of zero or more attribute options (see Section 2.5.2). - - -Zeilenga LDAP Models [Page 11] - -INTERNET-DRAFT draft-ietf-ldapbis-models-10 15 February 2004 - - An attribute description is represented by the ABNF: + attributedescription = attributetype options attributetype = oid options = *( SEMI option ) option = 1*keychar + where identifies the attribute type and each