From 226eb41733900bef10ca94e8951e603eceb80b9b Mon Sep 17 00:00:00 2001 From: Kurt Zeilenga Date: Fri, 4 Feb 2005 18:29:57 +0000 Subject: [PATCH] revision 29 --- doc/drafts/draft-ietf-ldapbis-protocol-xx.txt | 2061 +++++++++-------- 1 file changed, 1111 insertions(+), 950 deletions(-) diff --git a/doc/drafts/draft-ietf-ldapbis-protocol-xx.txt b/doc/drafts/draft-ietf-ldapbis-protocol-xx.txt index 3e03c3068e..cd9a124c0c 100644 --- a/doc/drafts/draft-ietf-ldapbis-protocol-xx.txt +++ b/doc/drafts/draft-ietf-ldapbis-protocol-xx.txt @@ -1,6 +1,7 @@ + Internet-Draft Editor: J. Sermersheim Intended Category: Standard Track Novell, Inc -Document: draft-ietf-ldapbis-protocol-27.txt Oct 2004 +Document: draft-ietf-ldapbis-protocol-29.txt Feb 2005 Obsoletes: RFCs 2251, 2830, 3771 @@ -53,23 +54,24 @@ Abstract Protocol (DAP). -Sermersheim Internet-Draft - Expires Apr 2005 Page 1 +Sermersheim Internet-Draft - Expires Aug 2005 Page 1 + Lightweight Directory Access Protocol Version 3 Table of Contents 1. Introduction....................................................3 - 1.1. Relationship to Obsolete Specifications.......................3 + 1.1. Relationship to Other LDAP Specifications.....................3 2. Conventions.....................................................3 3. Protocol Model..................................................4 - 3.1 Operation and LDAP Exchange Relationship.......................4 + 3.1 Operation and LDAP Message Layer Relationship..................4 4. Elements of Protocol............................................5 4.1. Common Elements...............................................5 4.1.1. Message Envelope............................................5 4.1.2. String Types................................................7 4.1.3. Distinguished Name and Relative Distinguished Name..........7 - 4.1.4. Attribute Descriptions......................................7 + 4.1.4. Attribute Descriptions......................................8 4.1.5. Attribute Value.............................................8 4.1.6. Attribute Value Assertion...................................8 4.1.7. Attribute and PartialAttribute..............................9 @@ -80,38 +82,39 @@ Table of Contents 4.2. Bind Operation...............................................14 4.3. Unbind Operation.............................................17 4.4. Unsolicited Notification.....................................17 - 4.5. Search Operation.............................................18 - 4.6. Modify Operation.............................................27 - 4.7. Add Operation................................................28 - 4.8. Delete Operation.............................................29 - 4.9. Modify DN Operation..........................................30 - 4.10. Compare Operation...........................................31 - 4.11. Abandon Operation...........................................32 - 4.12. Extended Operation..........................................32 - 4.13. IntermediateResponse Message................................34 - 4.13.1. Usage with LDAP ExtendedRequest and ExtendedResponse......34 - 4.13.2. Usage with LDAP Request Controls..........................35 - 4.14. StartTLS Operation..........................................35 - 5. Protocol Encoding, Connection, and Transfer....................37 - 5.2. Protocol Encoding............................................37 - 5.3. Transmission Control Protocol (TCP)..........................38 - 6. Security Considerations........................................38 - 7. Acknowledgements...............................................39 - 8. Normative References...........................................40 - 9. Informative References.........................................41 - 10. IANA Considerations...........................................42 - 11. Editor's Address..............................................42 - Appendix A - LDAP Result Codes....................................43 - A.1 Non-Error Result Codes........................................43 - A.2 Result Codes..................................................43 - Appendix B - Complete ASN.1 Definition............................48 - Appendix C - Changes..............................................54 - C.1 Changes made to RFC 2251:.....................................54 - C.2 Changes made to RFC 2830:.....................................59 - C.3 Changes made to RFC 3771:.....................................59 - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 2 + 4.6. Modify Operation.............................................28 + 4.7. Add Operation................................................29 + 4.8. Delete Operation.............................................30 + 4.9. Modify DN Operation..........................................31 + 4.10. Compare Operation...........................................32 + 4.11. Abandon Operation...........................................33 + 4.12. Extended Operation..........................................34 + 4.13. IntermediateResponse Message................................35 + 4.13.1. Usage with LDAP ExtendedRequest and ExtendedResponse......36 + 4.13.2. Usage with LDAP Request Controls..........................36 + 4.14. StartTLS Operation..........................................36 + 5. Protocol Encoding, Connection, and Transfer....................38 + 5.1. Protocol Encoding............................................38 + 5.2. Transmission Control Protocol (TCP)..........................39 + 5.3. Termination of the LDAP session..............................39 + 6. Security Considerations........................................39 + 7. Acknowledgements...............................................41 + 8. Normative References...........................................41 + 9. Informative References.........................................43 + 10. IANA Considerations...........................................43 + 11. Editor's Address..............................................43 + Appendix A - LDAP Result Codes....................................45 + A.1 Non-Error Result Codes........................................45 + A.2 Result Codes..................................................45 + Appendix B - Complete ASN.1 Definition............................50 + Appendix C - Changes..............................................56 + C.1 Changes made to RFC 2251:.....................................56 + C.2 Changes made to RFC 2830:.....................................61 + C.3 Changes made to RFC 3771:.....................................62 + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 2 + Lightweight Directory Access Protocol Version 3 @@ -131,7 +134,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 2 in which the protocol elements are encoded and transferred. -1.1. Relationship to Obsolete Specifications +1.1. Relationship to Other LDAP Specifications This document is an integral part of the LDAP Technical Specification [Roadmap] which obsoletes the previously defined LDAP technical @@ -169,22 +172,29 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 2 [CharModel]. -Sermersheim Internet-Draft - Expires Apr 2005 Page 3 +Sermersheim Internet-Draft - Expires Aug 2005 Page 3 + Lightweight Directory Access Protocol Version 3 - The term "connection" refers to the underlying transport service used - to carry the protocol exchange. + The term "transport connection" refers to the underlying transport + services used to carry the protocol exchange, as well as associations + established by these services. + + The term "TLS layer" refers to TLS services used in providing + security services, as well as associations established by these + services. - The term "LDAP exchange" refers to the layer where LDAP PDUs are - exchanged between protocol peers. + The term "SASL layer" refers to SASL services used in providing + security services, as well as associations established by these + services. - The term "TLS layer" refers to a layer inserted between the - connection and the LDAP exchange that utilizes Transport Layer - Security ([TLS]) to protect the exchange of LDAP PDUs. + The term "LDAP message layer" refers to the LDAP Message (PDU) + services used in providing directory services, as well as + associations established by these services. - The term "SASL layer" refers to a layer inserted between the - connection and the LDAP exchange that utilizes Simple Authentication - and Security Layer ([SASL]) to protect the exchange of LDAP PDUs. + The term "LDAP session" refers to combined services (transport + connection, TLS layer, SASL layer, LDAP message layer) and their + associations. See the table in Section 5 for an illustration of these four terms. @@ -218,18 +228,19 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 3 make multiple DAP requests to service a single LDAP request. -3.1 Operation and LDAP Exchange Relationship +3.1 Operation and LDAP Message Layer Relationship - Protocol operations are tied to an LDAP exchange. When the connection - is closed, any uncompleted operations tied to the LDAP exchange are, - when possible, abandoned, and when not possible, completed without - transmission of the response. Also, when the connection is closed, - the client MUST NOT assume that any uncompleted update operations - tied to the LDAP exchange have succeeded or failed. -Sermersheim Internet-Draft - Expires Apr 2005 Page 4 +Sermersheim Internet-Draft - Expires Aug 2005 Page 4 + Lightweight Directory Access Protocol Version 3 + Protocol operations are exchanged at the LDAP message layer. When the + transport connection is closed, any uncompleted operations at the + LDAP message layer, when possible, are abandoned, and when not + possible, are completed without transmission of the response. Also, + when the transport connection is closed, the client MUST NOT assume + that any uncompleted update operations have succeeded or failed. 4. Elements of Protocol @@ -249,13 +260,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 4 Changes to the protocol other than through the extension mechanisms described here require a different version number. A client indicates - the version it is using as part of the bind request, described in - Section 4.2. If a client has not sent a bind, the server MUST assume + the version it is using as part of the BindRequest, described in + Section 4.2. If a client has not sent a Bind, the server MUST assume the client is using version 3 or later. - Clients may determine the protocol versions a server supports by - reading the 'supportedLDAPVersion' attribute from the root DSE (DSA- - Specific Entry) [Models]. + Clients may attempt to determine the protocol versions a server + supports by reading the 'supportedLDAPVersion' attribute from the + root DSE (DSA-Specific Entry) [Models]. 4.1. Common Elements @@ -278,16 +289,17 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 4 bindResponse BindResponse, unbindRequest UnbindRequest, searchRequest SearchRequest, + +Sermersheim Internet-Draft - Expires Aug 2005 Page 5 + + Lightweight Directory Access Protocol Version 3 + searchResEntry SearchResultEntry, searchResDone SearchResultDone, searchResRef SearchResultReference, modifyRequest ModifyRequest, modifyResponse ModifyResponse, addRequest AddRequest, - -Sermersheim Internet-Draft - Expires Apr 2005 Page 5 - Lightweight Directory Access Protocol Version 3 - addResponse AddResponse, delRequest DelRequest, delResponse DelResponse, @@ -318,13 +330,15 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 5 encoding structures or lengths of data fields are found to be incorrect, then the server SHOULD return the Notice of Disconnection described in Section 4.4.1, with the resultCode set to protocolError, - and MUST immediately close the connection. + and MUST immediately terminate the LDAP session as described in + Section 5.3. In other cases where the client or server cannot parse a PDU, it - SHOULD abruptly close the connection where further communication - (including providing notice) would be pernicious. Otherwise, server - implementations MUST return an appropriate response to the request, - with the resultCode set to protocolError. + SHOULD abruptly terminate the LDAP session (Section 5.3) where + further communication (including providing notice) would be + pernicious. Otherwise, server implementations MUST return an + appropriate response to the request, with the resultCode set to + protocolError. 4.1.1.1. Message ID @@ -333,22 +347,24 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 5 messageID value of the corresponding request LDAPMessage. The message ID of a request MUST have a non-zero value different from - the the messageID of any other uncompleted requests in the LDAP - exchange. The zero value is reserved for the unsolicited notification + the messageID of any other request in progress in the same LDAP + +Sermersheim Internet-Draft - Expires Aug 2005 Page 6 + + Lightweight Directory Access Protocol Version 3 + + session. The zero value is reserved for the unsolicited notification message. Typical clients increment a counter for each request. A client MUST NOT send a request with the same message ID as an - earlier request in the same LDAP exchange unless it can be determined + earlier request in the same LDAP session unless it can be determined that the server is no longer servicing the earlier request (e.g. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 6 - Lightweight Directory Access Protocol Version 3 - - after the final response is received, or a subsequent bind + after the final response is received, or a subsequent Bind completes). Otherwise the behavior is undefined. For this purpose, - note that abandon and abandoned operations do not send responses. + note that Abandon and successfully abandoned operations do not send + responses. 4.1.2. String Types @@ -391,6 +407,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 6 RelativeLDAPDN ::= LDAPString -- Constrained to [LDAPDN] + +Sermersheim Internet-Draft - Expires Aug 2005 Page 7 + + Lightweight Directory Access Protocol Version 3 + 4.1.4. Attribute Descriptions @@ -400,10 +421,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 6 is an attribute type and zero or more options. AttributeDescription ::= LDAPString - -Sermersheim Internet-Draft - Expires Apr 2005 Page 7 - Lightweight Directory Access Protocol Version 3 - -- Constrained to -- [Models] @@ -438,7 +455,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 7 The AttributeValueAssertion (AVA) type definition is similar to the one in the X.500 Directory standards. It contains an attribute - description and a matching rule ([Models Section 4.1.3) assertion + description and a matching rule ([Models] Section 4.1.3) assertion value suitable for that type. Elements of this type are typically used to assert that the value in assertionValue matches a value of an attribute. @@ -449,6 +466,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 7 AssertionValue ::= OCTET STRING + +Sermersheim Internet-Draft - Expires Aug 2005 Page 8 + + Lightweight Directory Access Protocol Version 3 + The syntax of the AssertionValue depends on the context of the LDAP operation being performed. For example, the syntax of the EQUALITY matching rule for an attribute is used when performing a Compare @@ -458,10 +480,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 7 [Syntaxes] for an example. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 8 - Lightweight Directory Access Protocol Version 3 - 4.1.7. Attribute and PartialAttribute Attributes and partial attributes consist of an attribute description @@ -476,8 +494,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 8 ..., vals (SIZE(1..MAX))}) - No two attribute values may be equivalent as described by Section 2.3 - of [Models]. The set of attribute values is unordered. + No two of the attribute values may be equivalent as described by + Section 2.3 of [Models]. The set of attribute values is unordered. Implementations MUST NOT rely upon the ordering being repeatable. @@ -495,9 +513,9 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 8 The LDAPResult is the construct used in this protocol to return success or failure indications from servers to clients. To various - requests, servers will return responses of LDAPResult or responses - containing the components of LDAPResult to indicate the final status - of a protocol operation request. + requests, servers will return responses containing the elements found + in LDAPResult to indicate the final status of the protocol operation + request. LDAPResult ::= SEQUENCE { resultCode ENUMERATED { @@ -507,19 +525,20 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 8 timeLimitExceeded (3), sizeLimitExceeded (4), compareFalse (5), + +Sermersheim Internet-Draft - Expires Aug 2005 Page 9 + + Lightweight Directory Access Protocol Version 3 + compareTrue (6), authMethodNotSupported (7), - strongAuthRequired (8), + strongerAuthRequired (8), -- 9 reserved -- referral (10), adminLimitExceeded (11), unavailableCriticalExtension (12), confidentialityRequired (13), saslBindInProgress (14), - -Sermersheim Internet-Draft - Expires Apr 2005 Page 9 - Lightweight Directory Access Protocol Version 3 - noSuchAttribute (16), undefinedAttributeType (17), inappropriateMatching (18), @@ -565,24 +584,25 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 9 The diagnosticMessage field of this construct may, at the server's option, be used to return a string containing a textual, human- readable (terminal control and page formatting characters should be + +Sermersheim Internet-Draft - Expires Aug 2005 Page 10 + + Lightweight Directory Access Protocol Version 3 + avoided) diagnostic message. As this diagnostic message is not standardized, implementations MUST NOT rely on the values returned. - If the server chooses not to return a textual diagnostic, the - diagnosticMessage field MUST be empty. + Diagnostic messages typically supplement the resultCode with + additional information. If the server chooses not to return a textual + diagnostic, the diagnosticMessage field MUST be empty. For certain result codes (typically, but not restricted to noSuchObject, aliasProblem, invalidDNSyntax and aliasDereferencingProblem), the matchedDN field is set (subject to access controls) to the name of the last entry (object or alias) used - -Sermersheim Internet-Draft - Expires Apr 2005 Page 10 - Lightweight Directory Access Protocol Version 3 - - in finding the target (or base) object. If no aliases were - dereferenced while attempting to locate the entry, this will be a - truncated form of the name provided or if aliases were dereferenced, - of the resulting name, as defined in Section 12.5 of [X.511]. - Otherwise the matchedDN field is empty. + in finding the target (or base) object. This will be a truncated form + of the provided name or, if an alias was dereferenced while + attempting to locate the entry, of the resulting name. Otherwise the + matchedDN field is empty. 4.1.10. Referral @@ -597,15 +617,15 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 10 - The operation is restricted on this server -- perhaps due to a read-only copy of an entry to be modified. - The referral field is present in an LDAPResult if the resultCode - field value is referral, and absent with all other result codes. It - contains one or more references to one or more servers or services - that may be accessed via LDAP or other protocols. Referrals can be - returned in response to any operation request (except unbind and - abandon which do not have responses). At least one URI MUST be - present in the Referral. + The referral field is present in an LDAPResult if the resultCode is + set to referral, and absent with all other result codes. It contains + one or more references to one or more servers or services that may be + accessed via LDAP or other protocols. Referrals can be returned in + response to any operation request (except Unbind and Abandon which do + not have responses). At least one URI MUST be present in the + Referral. - During a search operation, after the baseObject is located, and + During a Search operation, after the baseObject is located, and entries are being evaluated, the referral is not returned. Instead, continuation references, described in Section 4.5.3, are returned when other servers would need to be contacted to complete the @@ -616,54 +636,51 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 10 URI ::= LDAPString -- limited to characters permitted in -- URIs - If the client wishes to progress the operation, it MUST follow the - referral by contacting one of the supported services. If multiple - URIs are present, the client assumes that any supported URI may be - used to progress the operation. + If the client wishes to progress the operation, it contacts one of + the supported services found in the referral. If multiple URIs are + present, the client assumes that any supported URI may be used to + progress the operation. - Protocol peers that follow referrals MUST ensure that they do not - loop between servers. They MUST NOT repeatedly contact the same - server for the same request with the same target entry name, scope - and filter. Some implementations use a counter that is incremented - each time referral handling occurs for an operation, and these kinds - of implementations MUST be able to handle at least ten nested - referrals between the root and a leaf entry. + Clients that follow referrals MUST ensure that they do not loop + between servers. They MUST NOT repeatedly contact the same server for + +Sermersheim Internet-Draft - Expires Aug 2005 Page 11 + + Lightweight Directory Access Protocol Version 3 + + the same request with the same parameters. Some clients use a counter + that is incremented each time referral handling occurs for an + operation, and these kinds of clients MUST be able to handle at least + ten nested referrals while progressing the operation. A URI for a server implementing LDAP and accessible via [TCP]/[IP] (v4 or v6) is written as an LDAP URL according to [LDAPURL]. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 11 - Lightweight Directory Access Protocol Version 3 - - When an LDAP URL is used, the following instructions are followed: + Referral values which are LDAP URLs follow these rules: - - If an alias was dereferenced, the part of the URL MUST be - present, with the new target object name. UTF-8 encoded characters - appearing in the string representation of a DN or search filter - may not be legal for URLs (e.g. spaces) and MUST be escaped using - the % method in [URI]. + - If an alias was dereferenced, the part of the LDAP URL MUST + be present, with the new target object name. - It is RECOMMENDED that the part be present to avoid ambiguity. - - If the part is present, the client MUST use this name in its - next request to progress the operation, and if it is not present - the client will use the same name as in the original request. + - If the part is present, the client uses this name in its next + request to progress the operation, and if it is not present the + client uses the same name as in the original request. - Some servers (e.g. participating in distributed indexing) may - provide a different filter in a URL of a referral for a search + provide a different filter in a URL of a referral for a Search operation. - - If the part of the LDAP URL is present, the client MUST - use this filter in its next request to progress this search, and - if it is not present the client MUST use the same filter as it - used for that search. + - If the part of the LDAP URL is present, the client uses + this filter in its next request to progress this Search, and if it + is not present the client uses the same filter as it used for that + Search. - - For search, it is RECOMMENDED that the part be present to + - For Search, it is RECOMMENDED that the part be present to avoid ambiguity. - - If the part is missing, the scope of the original search + - If the part is missing, the scope of the original Search is used by the client to progress the operation. - Other aspects of the new request may be the same as or different @@ -673,6 +690,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 11 URIs is left to future specifications. Clients may ignore URIs that they do not support. + UTF-8 encoded characters appearing in the string representation of a + DN, search filter, or other fields of the referral value may not be + legal for URIs (e.g. spaces) and MUST be escaped using the % method + in [URI]. + 4.1.11. Controls @@ -680,6 +702,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 11 existing LDAP operations may be extended. One or more controls may be attached to a single LDAP message. A control only affects the semantics of the message it is attached to. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 12 + + Lightweight Directory Access Protocol Version 3 + Controls sent by clients are termed 'request controls' and those sent by servers are termed 'response controls'. @@ -690,10 +717,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 11 controlType LDAPOID, criticality BOOLEAN DEFAULT FALSE, controlValue OCTET STRING OPTIONAL } - -Sermersheim Internet-Draft - Expires Apr 2005 Page 12 - Lightweight Directory Access Protocol Version 3 - The controlType field is the dotted-decimal representation of an OBJECT IDENTIFIER which uniquely identifies the control. This @@ -702,12 +725,12 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 12 request control. The criticality field only has meaning in controls attached to - request messages (except unbindRequest). For controls attached to - response messages and the unbindRequest, the criticality field SHOULD + request messages (except UnbindRequest). For controls attached to + response messages and the UnbindRequest, the criticality field SHOULD be FALSE, and MUST be ignored by the receiving protocol peer. A value of TRUE indicates that it is unacceptable to perform the operation - without applying the semantics of the control and FALSE otherwise. - Specifically, the criticality field is applied as follows: + without applying the semantics of the control. Specifically, the + criticality field is applied as follows: - Regardless of the value of the criticality field, if the server recognizes the control type and it is appropriate for the @@ -717,8 +740,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 12 - If the server does not recognize the control type or it is not appropriate for the operation, and the criticality field is TRUE, the server MUST NOT perform the operation, and for operations that - have a response message, MUST return unavailableCriticalExtension - in the resultCode. + have a response message, MUST return with the resultCode set to + unavailableCriticalExtension. - If the server does not recognize the control type or it is not appropriate for the operation, and the criticality field is FALSE, @@ -730,13 +753,19 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 12 contents of the controlValue octet string, including zero bytes. It is absent only if there is no value information which is associated with a control of its type. When a controlValue is defined in terms - of ASN.1, and BER encoded according to Section 5.2, it also follows + of ASN.1, and BER encoded according to Section 5.1, it also follows the extensibility rules in Section 4. Servers list the controlType of request controls they recognize in the 'supportedControl' attribute in the root DSE (Section 5.1 of [Models]). + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 13 + + Lightweight Directory Access Protocol Version 3 + Controls SHOULD NOT be combined unless the semantics of the combination has been specified. The semantics of control combinations, if specified, are generally found in the control @@ -747,12 +776,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 12 dependent semantics are given in a specification, the order of a combination of controls in the SEQUENCE is ignored. Where the order is to be ignored but cannot be ignored by the server, the message is - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 13 - Lightweight Directory Access Protocol Version 3 - considered not well-formed and the operation fails with protocolError. @@ -767,8 +790,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 13 are defined above should not be altered by the control's specification), - - whether information is to be present in the controlValue field, - and if so, the format of the controlValue contents, + - whether the controlValue field is present, and if so, the format + of its contents, - the semantics of the control, and @@ -778,13 +801,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 13 4.2. Bind Operation - The function of the Bind Operation is to allow authentication + The function of the Bind operation is to allow authentication information to be exchanged between the client and server. The Bind operation should be thought of as the "authenticate" operation. Operational, authentication, and security-related semantics of this operation are given in [AuthMeth]. - The Bind Request is defined as follows: + The Bind request is defined as follows: BindRequest ::= [APPLICATION 0] SEQUENCE { version INTEGER (1 .. 127), @@ -797,22 +820,23 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 13 sasl [3] SaslCredentials, ... } + +Sermersheim Internet-Draft - Expires Aug 2005 Page 14 + + Lightweight Directory Access Protocol Version 3 + SaslCredentials ::= SEQUENCE { mechanism LDAPString, credentials OCTET STRING OPTIONAL } - Fields of the Bind Request are: + Fields of the BindRequest are: - version: A version number indicating the version of the protocol - to be used for the LDAP exchange. This document describes version - 3 of the protocol. There is no version negotiation. The client - sets this field to the version it desires. If the server does not - -Sermersheim Internet-Draft - Expires Apr 2005 Page 14 - Lightweight Directory Access Protocol Version 3 - - support the specified version, it MUST respond with protocolError - in the resultCode field of the BindResponse. + to be used at the LDAP message layer. This document describes + version 3 of the protocol. There is no version negotiation. The + client sets this field to the version it desires. If the server + does not support the specified version, it MUST respond with a + BindResponse where the resultCode is set to protocolError. - name: If not empty, the name of the Directory object that the client wishes to bind as. This field may take on a null value (a @@ -824,9 +848,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 14 - authentication: information used in authentication. This type is extensible as defined in Section 3.7 of [LDAPIANA]. Servers that - do not support a choice supplied by a client return - authMethodNotSupported in the resultCode field of the - BindResponse. + do not support a choice supplied by a client return a BindResponse + with the resultCode set to authMethodNotSupported. Textual passwords (consisting of a character sequence with a known character set and encoding) transferred to the server using the @@ -837,12 +860,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 14 octets) MUST NOT be altered. The determination of whether a password is textual is a local client matter. - Authorization is the decision of which access an operation has to the - directory. Among other things, the process of authorization takes as - input authentication information obtained during the bind operation - and/or other acts of authentication (such as lower layer security - services). - 4.2.1. Processing of the Bind Request @@ -850,7 +867,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 14 either complete or be abandoned. The server may either wait for the uncompleted operations to complete, or abandon them. The server then proceeds to authenticate the client in either a single-step, or - multi-step bind process. Each step requires the server to return a + multi-step Bind process. Each step requires the server to return a BindResponse to indicate the status of authentication. After sending a BindRequest, clients MUST NOT send further LDAP PDUs @@ -859,40 +876,40 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 14 BindRequest. If the client did not bind before sending a request and receives an - operationsError to that request, it may then send a Bind Request. If + operationsError to that request, it may then send a BindRequest. If this also fails or the client chooses not to bind on the existing - LDAP exchange, it may close the connection, reopen it and begin again - by first sending a PDU with a Bind Request. This will aid in - interoperating with servers implementing other versions of LDAP. - + LDAP session, it may terminate the LDAP session, re-establish it and -Sermersheim Internet-Draft - Expires Apr 2005 Page 15 +Sermersheim Internet-Draft - Expires Aug 2005 Page 15 + Lightweight Directory Access Protocol Version 3 - Clients may send multiple Bind Requests on an LDAP exchange to change - the authentication and/or security associations or to complete a - multi-stage bind process. Authentication from earlier binds is - subsequently ignored. + begin again by first sending a PDU with a BindRequest. This will aid + in interoperating with servers implementing other versions of LDAP. + + Clients may send multiple Bind requests to change the authentication + and/or security associations or to complete a multi-stage Bind + process. Authentication from earlier binds is subsequently ignored. For some SASL authentication mechanisms, it may be necessary for the client to invoke the BindRequest multiple times ([AuthMeth] Section - 8.2). Clients MUST NOT invoke operations between two Bind Requests - made as part of a multi-stage bind. + 8.2). Clients MUST NOT invoke operations between two Bind requests + made as part of a multi-stage Bind. 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. If the client sends a BindRequest with the sasl mechanism field as an - empty string, the server MUST return a BindResponse with - authMethodNotSupported as the resultCode. This will allow clients to + empty string, the server MUST return a BindResponse with the + resultCode set to authMethodNotSupported. This will allow clients to abort a negotiation if it wishes to try again with the same SASL mechanism. 4.2.2. Bind Response - The Bind Response is defined as follows. + The Bind response is defined as follows. BindResponse ::= [APPLICATION 1] SEQUENCE { COMPONENTS OF LDAPResult, @@ -901,49 +918,51 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 15 BindResponse consists simply of an indication from the server of the status of the client's request for authentication. - A successful bind operation is indicated by a BindResponse with a + A successful Bind operation is indicated by a BindResponse with a resultCode set to success. Otherwise, an appropriate result code is - set in the BindResponse. For bind, the protocolError result code may - be used to indicate that the version number supplied by the client is - unsupported. + set in the BindResponse. For BindResponse, the protocolError result + code may be used to indicate that the version number supplied by the + client is unsupported. - If the client receives a BindResponse where the resultCode field is + If the client receives a BindResponse where the resultCode is set to protocolError, it is to assume that the server does not support this version of LDAP. While the client may be able proceed with another version of this protocol (this may or may not require closing and re- - establishing the connection), how to proceed with another version of - this protocol is beyond the scope of this document. Clients which are - unable or unwilling to proceed SHOULD close the connection. + establishing the transport connection), how to proceed with another + version of this protocol is beyond the scope of this document. + Clients which are unable or unwilling to proceed SHOULD terminate the + LDAP session. The serverSaslCreds field is used as part of a SASL-defined bind mechanism to allow the client to authenticate the server to which it is communicating, or to perform "challenge-response" authentication. If the client bound with the simple choice, or the SASL mechanism + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 16 + + Lightweight Directory Access Protocol Version 3 + does not require the server to return information to the client, then this field SHALL NOT be included in the BindResponse. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 16 - Lightweight Directory Access Protocol Version 3 - 4.3. Unbind Operation - The function of the Unbind Operation is to terminate an LDAP exchange - and close the connection. The Unbind operation is not the antithesis - of the Bind operation as the name implies. The naming of these - operations is historical. The Unbind operation should be thought of - as the "quit" operation. + The function of the Unbind operation is to terminate an LDAP session. + The Unbind operation is not the antithesis of the Bind operation as + the name implies. The naming of these operations are historical. The + Unbind operation should be thought of as the "quit" operation. - The Unbind Operation is defined as follows: + The Unbind operation is defined as follows: UnbindRequest ::= [APPLICATION 2] NULL - The Unbind Operation has no response defined. Upon transmission of - the UnbindRequest, each protocol peer is to consider the LDAP - exchange terminated, MUST cease transmission of messages to the other - peer, and MUST close the connection. Uncompleted operations are - handled as specified in Section 5.1. + The client, upon transmission of the UnbindRequest, and the server, + upon receipt of the UnbindRequest are to gracefully terminate the + LDAP session as described in Section 5.3. + + Uncompleted operations are handled as specified in Section 3.1. 4.4. Unsolicited Notification @@ -951,14 +970,15 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 16 An unsolicited notification is an LDAPMessage sent from the server to the client which is not in response to any LDAPMessage received by the server. It is used to signal an extraordinary condition in the - server or in the LDAP exchange or connection between the client and - the server. The notification is of an advisory nature, and the server - will not expect any response to be returned from the client. + server or in the LDAP session between the client and the server. The + notification is of an advisory nature, and the server will not expect + any response to be returned from the client. The unsolicited notification is structured as an LDAPMessage in which - the messageID is zero and protocolOp is of the extendedResp form (See - Section 4.12). The responseName field of the ExtendedResponse always - contains an LDAPOID which is unique for this notification. + the messageID is zero and protocolOp is set to the extendedResp + choice using the ExtendedResponse type (See Section 4.12). The + responseName field of the ExtendedResponse always contains an LDAPOID + which is unique for this notification. One unsolicited notification (Notice of Disconnection) is defined in this document. The specification of an unsolicited notification @@ -967,40 +987,43 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 16 - the OBJECT IDENTIFIER assigned to the notification (to be specified in the responseName, - - the format of the contents (if any) of the responseValue, + - the format of the contents of the responseValue (if any), - - the circumstances which will cause the notification to be - returned, and + - the circumstances which will cause the notification to be sent, + and - - the semantics of the operation. + - the semantics of the message. 4.4.1. Notice of Disconnection - This notification may be used by the server to advise the client that - the server is about to close the connection due to an error - condition. This notification is intended to assist clients in - distinguishing between an error condition and a transient network -Sermersheim Internet-Draft - Expires Apr 2005 Page 17 +Sermersheim Internet-Draft - Expires Aug 2005 Page 17 + Lightweight Directory Access Protocol Version 3 - failure. Note that this notification is not a response to an unbind - requested by the client. Uncompleted operations are handled as - specified in Section 5.1. + This notification may be used by the server to advise the client that + the server is about to terminate the LDAP session on its own + initiative. This notification is intended to assist clients in + distinguishing between an exceptional server condition and a + transient network failure. Note that this notification is not a + response to an Unbind requested by the client. Uncompleted operations + are handled as specified in Section 3.1. The responseName is 1.3.6.1.4.1.1466.20036, the responseValue field is absent, and the resultCode is used to indicate the reason for the - disconnection. + disconnection. When the strongerAuthRequired resultCode is returned + with this message, it indicates that the server has detected that an + established security association between the client and server has + unexpectedly failed or been compromised. - Upon transmission of the Notice of Disconnection, the server is to - consider the LDAP exchange terminated, MUST cease transmission of - messages to the client, and MUST close the connection. + Upon transmission of the Notice of Disconnection, the server + gracefully terminates the LDAP session as described in Section 5.3. 4.5. Search Operation - The Search Operation is used to request a server to return, subject + The Search operation is used to request a server to return, subject to access controls and other restrictions, a set of entries matching a complex search criterion. This can be used to read attributes from a single entry, from entries immediately subordinate to a particular @@ -1009,14 +1032,15 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 17 4.5.1. Search Request - The Search Request is defined as follows: + The Search request is defined as follows: SearchRequest ::= [APPLICATION 3] SEQUENCE { baseObject LDAPDN, scope ENUMERATED { baseObject (0), singleLevel (1), - wholeSubtree (2) }, + wholeSubtree (2), + ... }, derefAliases ENUMERATED { neverDerefAliases (0), derefInSearching (1), @@ -1030,31 +1054,33 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 17 AttributeSelection ::= SEQUENCE OF selector LDAPString -- The LDAPString is constrained to - -- below + -- in Section 4.5.1.7 + +Sermersheim Internet-Draft - Expires Aug 2005 Page 18 + + Lightweight Directory Access Protocol Version 3 + Filter ::= CHOICE { - and [0] SET OF filter Filter, - or [1] SET OF filter Filter, + 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, - -Sermersheim Internet-Draft - Expires Apr 2005 Page 18 - Lightweight Directory Access Protocol Version 3 - lessOrEqual [6] AttributeValueAssertion, present [7] AttributeDescription, approxMatch [8] AttributeValueAssertion, - extensibleMatch [9] MatchingRuleAssertion } + 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, + initial [0] AssertionValue, -- can occur at most once any [1] AssertionValue, - final [2] AssertionValue } } + final [2] AssertionValue } -- can occur at most once + } MatchingRuleAssertion ::= SEQUENCE { matchingRule [1] MatchingRuleId OPTIONAL, @@ -1062,209 +1088,275 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 18 matchValue [3] AssertionValue, dnAttributes [4] BOOLEAN DEFAULT FALSE } - Fields of the Search Request are: + Note that an X.500 "list"-like operation can be emulated by the + client requesting a singleLevel Search operation with a filter + checking for the presence of the 'objectClass' attribute, and that an + X.500 "read"-like operation can be emulated by a baseObject Search + operation with the same filter. A server which provides a gateway to + X.500 is not required to use the Read or List operations, although it + may choose to do so, and if it does, it must provide the same + semantics as the X.500 Search operation. + + +4.5.1.1 SearchRequest.baseObject - - baseObject: The name of the base object entry relative to which - the search is to be performed. + The name of the base object entry (or possibly the root) relative to + which the Search is to be performed. - - scope: Specifies the scope of the search to be performed. The - semantics (as described in [X.511]) of the possible values of this - field are: - - baseObject: The scope is constrained to the entry named by - baseObject. - - singleLevel: The scope is constrained to the immediate - subordinates of the entry named by baseObject. - - wholeSubtree: the scope is constrained to the entry named by - the baseObject, and all its subordinates. +4.5.1.2 SearchRequest.scope + + Specifies the scope of the Search to be performed. The semantics (as + described in [X.511]) of the defined values of this field are: - - derefAliases: An indicator as to how alias entries (as defined in - [Models]) are to be handled in searching. The semantics of the - possible values of this field are: - - neverDerefAliases: Do not dereference aliases in searching or - in locating the base object of the search. - - derefInSearching: While searching, dereference any alias entry - subordinate to the base object which is also in the search - scope. The filter is applied to the dereferenced object(s). If - the search scope is wholeSubtree, the search continues in the - subtree of any dereferenced object. Aliases in that subtree are - also dereferenced. Servers SHOULD eliminate duplicate entries - that arise due to alias dereferencing while searching. - - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 19 - Lightweight Directory Access Protocol Version 3 - - derefFindingBaseObj: Dereference aliases in locating the base - object of the search, but not when searching subordinates of - the base object. - - derefAlways: Dereference aliases both in searching and in - locating the base object of the search. - Servers MUST detect looping while dereferencing aliases in order - to prevent denial of service attacks of this nature. - - - sizeLimit: A size limit that restricts the maximum number of - entries to be returned as a result of the search. A value of zero - in this field indicates that no client-requested size limit - restrictions are in effect for the search. Servers may also - enforce a maximum number of entries to return. - - - timeLimit: A time limit that restricts the maximum time (in - seconds) allowed for a search. A value of zero in this field - indicates that no client-requested time limit restrictions are in - effect for the search. Servers may also enforce a maximum time - limit for the search. - - - typesOnly: An indicator as to whether search results are to - contain both attribute descriptions and values, or just attribute - descriptions. Setting this field to TRUE causes only attribute - descriptions (no values) to be returned. Setting this field to - FALSE causes both attribute descriptions and values to be - returned. - - - filter: A filter that defines the conditions that must be - fulfilled in order for the search to match a given entry. + baseObject: The scope is constrained to the entry named by + baseObject. - The 'and', 'or' and 'not' choices can be used to form combinations - of filters. At least one filter element MUST be present in an - 'and' or 'or' choice. The others match against individual - attribute values of entries in the scope of the search. - (Implementor's note: the 'not' filter is an example of a tagged - choice in an implicitly-tagged module. In BER this is treated as - if the tag was explicit.) - - A server MUST evaluate filters according to the three-valued logic - of X.511 (1993) Section 7.8.1. In summary, a filter is evaluated - to either "TRUE", "FALSE" or "Undefined". If the filter evaluates - to TRUE for a particular entry, then the attributes of that entry - are returned as part of the search result (subject to any - applicable access control restrictions). If the filter evaluates - to FALSE or Undefined, then the entry is ignored for the search. + singleLevel: The scope is constrained to the immediate + subordinates of the entry named by baseObject. - A filter of the "and" choice is TRUE if all the filters in the SET - OF evaluate to TRUE, FALSE if at least one filter is FALSE, and - otherwise Undefined. A filter of the "or" choice is FALSE if all - of the filters in the SET OF evaluate to FALSE, TRUE if at least - one filter is TRUE, and Undefined otherwise. A filter of the 'not' - choice is TRUE if the filter being negated is FALSE, FALSE if it - is TRUE, and Undefined if it is Undefined. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 20 + +Sermersheim Internet-Draft - Expires Aug 2005 Page 19 + Lightweight Directory Access Protocol Version 3 + wholeSubtree: the scope is constrained to the entry named by the + baseObject, and all its subordinates. + + +4.5.1.3 SearchRequest.derefAliases + + An indicator as to whether or not alias entries (as defined in + [Models]) are to be dereferenced during stages of the Search + operation. + + The act of dereferencing an alias includes recursively dereferencing + aliases which refer to aliases. + + Servers MUST detect looping while dereferencing aliases in order to + prevent denial of service attacks of this nature. + + The semantics of the defined values of this field are: + + neverDerefAliases: Do not dereference aliases in searching or in + locating the base object of the Search. - The present match evaluates to TRUE where there is an attribute or - subtype of the specified attribute description present in an - entry, and FALSE otherwise (including a presence test with an - unrecognized attribute description.) + derefInSearching: While searching subordinates of the base object, + dereference any alias within the search scope. Dereferenced + objects become the vertices of further search scopes where the + Search operation is also applied. If the search scope is + wholeSubtree, the Search continues in the subtree(s) of any + dereferenced object. If the search scope is singleLevel, the + search is applied to any dereferenced objects, and is not applied + to their subordinates. Servers SHOULD eliminate duplicate entries + that arise due to alias dereferencing while searching. - The matching rule for equalityMatch filter items is defined by the - EQUALITY matching rule for the attribute type. - - There SHALL be at most one 'initial', and at most one 'final' in - the 'substrings' of a SubstringFilter. If 'initial' is present, it - SHALL be the first element of 'substrings'. If 'final' is present, - it SHALL be the last element of 'substrings'. - The matching rule for AssertionValues in a substrings filter item - is defined by the SUBSTR matching rule for the attribute type. - Note that the AssertionValue in a substrings filter item conforms - to the assertion syntax of the EQUALITY matching rule for the - attribute type rather than the assertion syntax of the SUBSTR - matching rule for the attribute type. Conceptually, the entire - SubstringFilter is converted into an assertion value of the - substrings matching rule prior to applying the rule. - - The matching rule for the greaterOrEqual filter item is defined by - the ORDERING and EQUALITY matching rules for the attribute type. - - The matching rule for the lessOrEqual filter item is defined by - the ORDERING matching rule for the attribute type. - - An approxMatch filter item evaluates to TRUE when there is a value - of the attribute or subtype for which some locally-defined - approximate matching algorithm (e.g. spelling variations, phonetic - match, etc.) returns TRUE. If an item matches for equality, it - also satisfies an approximate match. If approximate matching is - not supported for the attribute, this filter item should be - treated as an equalityMatch. + derefFindingBaseObj: Dereference aliases in locating the base + object of the Search, but not when searching subordinates of the + base object. - An extensibleMatch filter item is evaluated as follows: + derefAlways: Dereference aliases both in searching and in locating + the base object of the Search. + - If the matchingRule field is absent, the type field MUST be - present, and an equality match is performed for that type. - - If the type field is absent and the matchingRule is present, the - matchValue is compared against all attributes in an entry which - support that matchingRule. The matchingRule determines the - syntax for the assertion value. The filter item evaluates to - TRUE if it matches with at least one attribute in the entry, - FALSE if it does not match any attribute in the entry, and - Undefined if the matchingRule is not recognized or the - assertionValue is invalid. - - If the type field is present and the matchingRule is present, - the matchValue is compared against entry attributes of the - specified type. In this case, the matchingRule MUST be one - +4.5.1.4 SearchRequest.sizeLimit + + A size limit that restricts the maximum number of entries to be + returned as a result of the Search. A value of zero in this field + indicates that no client-requested size limit restrictions are in + effect for the Search. Servers may also enforce a maximum number of + entries to return. + + +4.5.1.5 SearchRequest.timeLimit + + A time limit that restricts the maximum time (in seconds) allowed for + a Search. A value of zero in this field indicates that no client- + requested time limit restrictions are in effect for the Search. + Servers may also enforce a maximum time limit for the Search. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 20 + + Lightweight Directory Access Protocol Version 3 + + + +4.5.1.6 SearchRequest.typesOnly + + An indicator as to whether Search results are to contain both + attribute descriptions and values, or just attribute descriptions. + Setting this field to TRUE causes only attribute descriptions (no + values) to be returned. Setting this field to FALSE causes both + attribute descriptions and values to be returned. + + +4.5.1.7 SearchRequest.filter + + A filter that defines the conditions that must be fulfilled in order + for the Search to match a given entry. + + The 'and', 'or' and 'not' choices can be used to form combinations of + filters. At least one filter element MUST be present in an 'and' or + 'or' choice. The others match against individual attribute values of + entries in the scope of the Search. (Implementor's note: the 'not' + filter is an example of a tagged choice in an implicitly-tagged + module. In BER this is treated as if the tag was explicit.) + + A server MUST evaluate filters according to the three-valued logic of + [X.511] (1993) Clause 7.8.1. In summary, a filter is evaluated to + either "TRUE", "FALSE" or "Undefined". If the filter evaluates to + TRUE for a particular entry, then the attributes of that entry are + returned as part of the Search result (subject to any applicable + access control restrictions). If the filter evaluates to FALSE or + Undefined, then the entry is ignored for the Search. + + A filter of the "and" choice is TRUE if all the filters in the SET OF + evaluate to TRUE, FALSE if at least one filter is FALSE, and + otherwise Undefined. A filter of the "or" choice is FALSE if all of + the filters in the SET OF evaluate to FALSE, TRUE if at least one + filter is TRUE, and Undefined otherwise. A filter of the 'not' choice + is TRUE if the filter being negated is FALSE, FALSE if it is TRUE, + and Undefined if it is Undefined. + + A filter item evaluates to Undefined when the server would not be + able to determine whether the assertion value matches an entry. + Examples include: + + - An attribute description in an equalityMatch, substrings, + greaterOrEqual, lessOrEqual, approxMatch or extensibleMatch + filter is not recognized by the server. + + - The attribute type does not define the appropriate matching + rule. + + - A MatchingRuleId in the extensibleMatch is not recognized by + the server or is not valid for the attribute type. + + - The type of filtering requested is not implemented. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 21 + + Lightweight Directory Access Protocol Version 3 + + + - The assertion value is invalid. + + For example, if a server did not recognize the attribute type + shoeSize, a filter of (shoeSize=*) would evaluate to FALSE, and the + filters (shoeSize=12), (shoeSize>=12) and (shoeSize<=12) would each + evaluate to Undefined. + + Servers MUST NOT return errors if attribute descriptions or matching + rule ids are not recognized, assertion values are invalid, or the + assertion syntax is not supported. More details of filter processing + are given in Clause 7.8 of [X.511]. + + +4.5.1.7.1 SearchRequest.filter.equalityMatch + + The matching rule for equalityMatch filter items is defined by the + EQUALITY matching rule for the attribute type. + + +4.5.1.7.2 SearchRequest.filter.substrings + + There SHALL be at most one 'initial', and at most one 'final' in the + 'substrings' of a SubstringFilter. If 'initial' is present, it SHALL + be the first element of 'substrings'. If 'final' is present, it SHALL + be the last element of 'substrings'. + + The matching rule for an AssertionValue in a substrings filter item + is defined by the SUBSTR matching rule for the attribute type. Note + that the AssertionValue in a substrings filter item conforms to the + assertion syntax of the EQUALITY matching rule for the attribute type + rather than the assertion syntax of the SUBSTR matching rule for the + attribute type. Conceptually, the entire SubstringFilter is converted + into an assertion value of the substrings matching rule prior to + applying the rule. + + +4.5.1.7.3 SearchRequest.filter.greaterOrEqual + + The matching rule for the greaterOrEqual filter item is defined by + the ORDERING and EQUALITY matching rules for the attribute type. + + +4.5.1.7.4 SearchRequest.filter.lessOrEqual + + The matching rule for the lessOrEqual filter item is defined by the + ORDERING matching rule for the attribute type. + + +4.5.1.7.5 SearchRequest.filter.present + + The present match evaluates to TRUE where there is an attribute or + subtype of the specified attribute description present in an entry, -Sermersheim Internet-Draft - Expires Apr 2005 Page 21 +Sermersheim Internet-Draft - Expires Aug 2005 Page 22 + Lightweight Directory Access Protocol Version 3 - suitable for use with the specified type (see [Syntaxes]), - otherwise the filter item is Undefined. - - If the dnAttributes field is set to TRUE, the match is - additionally applied against all the AttributeValueAssertions in - an entry's distinguished name, and evaluates to TRUE if there is - at least one attribute in the distinguished name for which the - filter item evaluates to TRUE. The dnAttributes field is present - to alleviate the need for multiple versions of generic matching - rules (such as word matching), where one applies to entries and - another applies to entries and dn attributes as well. - - A filter item evaluates to Undefined when the server would not be - able to determine whether the assertion value matches an entry. - Examples include: - - - An attribute description in an equalityMatch, substrings, - greaterOrEqual, lessOrEqual, approxMatch or extensibleMatch - filter is not recognized by the server. - - - The attribute type does not define the appropriate matching - rule. - - - A MatchingRuleId in the extensibleMatch is not recognized by - the server or is not valid for the attribute type. + and FALSE otherwise (including a presence test with an unrecognized + attribute description). + + +4.5.1.7.6 SearchRequest.filter.approxMatch + + An approxMatch filter item evaluates to TRUE when there is a value of + the attribute or subtype for which some locally-defined approximate + matching algorithm (e.g. spelling variations, phonetic match, etc.) + returns TRUE. If an item matches for equality, it also satisfies an + approximate match. If approximate matching is not supported for the + attribute, this filter item should be treated as an equalityMatch. + + +4.5.1.7.7 SearchRequest.filter.extensibleMatch + + The fields of the extensibleMatch filter item are evaluated as + follows: + + - If the matchingRule field is absent, the type field MUST be + present, and an equality match is performed for that type. - - The type of filtering requested is not implemented. + - If the type field is absent and the matchingRule is present, the + matchValue is compared against all attributes in an entry which + support that matchingRule. + + - If the type field is present and the matchingRule is present, the + matchValue is compared against entry attributes of the specified + type. + + - If the dnAttributes field is set to TRUE, the match is + additionally applied against all the AttributeValueAssertions in + an entry's distinguished name, and evaluates to TRUE if there is + at least one attribute in the distinguished name for which the + filter item evaluates to TRUE. The dnAttributes field is present + to alleviate the need for multiple versions of generic matching + rules (such as word matching), where one applies to entries and + another applies to entries and DN attributes as well. - - The assertion value is invalid. + The matchingRule used for evaluation determines the syntax for the + assertion value. Once the matchingRule and attribute(s) have been + determined, the filter item evaluates to TRUE if it matches with at + least one attribute in the entry, FALSE if it does not match any + attribute in the entry, and Undefined if the matchingRule is not + recognized, the matchingRule is unsuitable for use with the specified + type, or the assertionValue is invalid. - For example, if a server did not recognize the attribute type - shoeSize, a filter of (shoeSize=*) would evaluate to FALSE, and - the filters (shoeSize=12), (shoeSize>=12) and (shoeSize<=12) would - each evaluate to Undefined. - - Servers MUST NOT return errors if attribute descriptions or - matching rule ids are not recognized, assertion values are - invalid, or the assertion syntax is not supported. More details of - filter processing are given in Section 7.8 of [X.511]. - - attributes: A selection list of the attributes to be returned from - each entry which matches the search filter. LDAPString values of - this field are constrained to the following Augmented Backus-Naur - Form ([ABNF]): +4.5.1.7 SearchRequest.attributes - attributeSelector = attributedescription / selectorpecial + A selection list of the attributes to be returned from each entry + which matches the search filter. LDAPString values of this field are + constrained to the following Augmented Backus-Naur Form ([ABNF]): + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 23 + + Lightweight Directory Access Protocol Version 3 + + attributeSelector = attributedescription / selectorspecial selectorspecial = noattrs / alluserattrs @@ -1272,22 +1364,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 21 alluserattrs = %x2A ; asterisk ("*") - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 22 - Lightweight Directory Access Protocol Version 3 - The production is defined in Section 2.5 of [Models]. - There are three special cases which may appear in the attributes - selection list: + There are three special cases which may appear in the attributes + selection list: - an empty list with no attributes, - a list containing "*" (with zero or more attribute - descriptions), and + descriptions), and - a list containing only "1.1". @@ -1302,60 +1388,45 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 22 This OID was chosen because it does not (and can not) correspond to any attribute in use. - Client implementors should note that even if all user attributes - are requested, some attributes and/or attribute values of the - entry may not be included in search results due to access controls - or other restrictions. Furthermore, servers will not return - operational attributes, such as objectClasses or attributeTypes, - unless they are listed by name. Operational attributes are - described in [Models]. - - Attributes are returned at most once in an entry. If an attribute - description is named more than once in the list, the subsequent - names are ignored. If an attribute description in the list is not - recognized, it is ignored by the server. - - Note that an X.500 "list"-like operation can be emulated by the - client requesting a one-level LDAP search operation with a filter - checking for the presence of the 'objectClass' attribute, and that an - X.500 "read"-like operation can be emulated by a base object LDAP - search operation with the same filter. A server which provides a - gateway to X.500 is not required to use the Read or List operations, - although it may choose to do so, and if it does, it must provide the - same semantics as the X.500 search operation. + Client implementors should note that even if all user attributes are + requested, some attributes and/or attribute values of the entry may + not be included in Search results due to access controls or other + restrictions. Furthermore, servers will not return operational + attributes, such as objectClasses or attributeTypes, unless they are + listed by name. Operational attributes are described in [Models]. + + Attributes are returned at most once in an entry. If an attribute + description is named more than once in the list, the subsequent names + are ignored. If an attribute description in the list is not + recognized, it is ignored by the server. 4.5.2. Search Result - The results of the search operation are returned as zero or more - searchResultEntry messages, zero or more SearchResultReference - messages, followed by a single searchResultDone message. + The results of the Search operation are returned as zero or more + SearchResultEntry and/or SearchResultReference messages, followed by + a single SearchResultDone message. SearchResultEntry ::= [APPLICATION 4] SEQUENCE { + objectName LDAPDN, + attributes PartialAttributeList } -Sermersheim Internet-Draft - Expires Apr 2005 Page 23 +Sermersheim Internet-Draft - Expires Aug 2005 Page 24 + Lightweight Directory Access Protocol Version 3 - objectName LDAPDN, - attributes PartialAttributeList } PartialAttributeList ::= SEQUENCE OF partialAttribute PartialAttribute - -- Note that the PartialAttributeList may hold zero elements. - -- This may happen when none of the attributes of an entry - -- were requested, or could be returned. - -- Note also that the partialAttribute vals set may hold zero - -- elements. This may happen when typesOnly is requested, access - -- controls prevent the return of values, or other reasons. SearchResultReference ::= [APPLICATION 19] SEQUENCE SIZE (1..MAX) OF uri URI SearchResultDone ::= [APPLICATION 5] LDAPResult - Each SearchResultEntry represents an entry found during the search. + Each SearchResultEntry represents an entry found during the Search. Each SearchResultReference represents an area not yet explored during - the search. The SearchResultEntry and SearchResultReference PDUs may + the Search. The SearchResultEntry and SearchResultReference PDUs may come in any order. Following all the SearchResultReference and SearchResultEntry responses, the server returns a SearchResultDone response, which contains an indication of success, or detailing any @@ -1363,8 +1434,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 23 Each entry returned in a SearchResultEntry will contain all appropriate attributes as specified in the attributes field of the - Search Request. Return of attributes is subject to access control and - other administrative policy. + Search Request, subject to access control and other administrative + policy. Note that the PartialAttributeList may hold zero elements. + This may happen when none of the attributes of an entry were + requested, or could be returned. Note also that the partialAttribute + vals set may hold zero elements. This may happen when typesOnly is + requested, access controls prevent the return of values, or other + reasons. Some attributes may be constructed by the server and appear in a SearchResultEntry attribute list, although they are not stored @@ -1383,93 +1459,102 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 23 4.5.3. Continuation References in the Search Result If the server was able to locate the entry referred to by the - baseObject but was unable to search one or more non-local entries, - the server may return one or more SearchResultReference entries, each - containing a reference to another set of servers for continuing the - operation. A server MUST NOT return any SearchResultReference if it - has not located the baseObject and thus has not searched any entries; - in this case it would return a SearchResultDone containing either a - - + baseObject but was unable or unwilling to search one or more non- + local entries, the server may return one or more + SearchResultReference messages, each containing a reference to + another set of servers for continuing the operation. A server MUST + NOT return any SearchResultReference messages if it has not located + the baseObject and thus has not searched any entries; in this case it + would return a SearchResultDone containing either a referral or + noSuchObject result code (depending on the server's knowledge of the + entry named in the baseObject). + -Sermersheim Internet-Draft - Expires Apr 2005 Page 24 +Sermersheim Internet-Draft - Expires Aug 2005 Page 25 + Lightweight Directory Access Protocol Version 3 - referral or noSuchObject result code (depending on the server's - knowledge of the entry named in the baseObject). - If a server holds a copy or partial copy of the subordinate naming - context [Section 5 of Models], it may use the search filter to + context (Section 5 of [Models]), it may use the search filter to determine whether or not to return a SearchResultReference response. Otherwise SearchResultReference responses are always returned when in scope. The SearchResultReference is of the same data type as the Referral. - A URI for a server implementing LDAP and accessible via [TCP]/[IP] - (v4 or v6) is written as an LDAP URL according to [LDAPURL]. - - In order to complete the search, the client issues a new search - operation for each SearchResultReference that is returned. Note that - the abandon operation described in Section 4.11 applies only to a - particular operation sent on the LDAP exchange between a client and - server. The client must abandon subsequent search operations it - wishes to individually. + If the client wishes to progress the Search, it issues a new Search + operation for each SearchResultReference that is returned. If + multiple URIs are present, the client assumes that any supported URI + may be used to progress the operation. Clients that follow search continuation references MUST ensure that they do not loop between servers. They MUST NOT repeatedly contact - the same server for the same request with the same target entry name, - scope and filter. Some clients use a counter that is incremented each - time search result reference handling occurs for an operation, and - these kinds of clients MUST be able to handle at least ten nested - search result references between the root and a leaf entry. + the same server for the same request with the same parameters. Some + clients use a counter that is incremented each time search result + reference handling occurs for an operation, and these kinds of + clients MUST be able to handle at least ten nested referrals while + progressing the operation. - When an LDAP URL is used, the following instructions are followed: + Note that the Abandon operation described in Section 4.11 applies + only to a particular operation sent at the LDAP message layer between + a client and server. The client must abandon subsequent Search + operations it wishes to individually. - - The part of the URL MUST be present, with the new target - object name. The client MUST use this name when following the - reference. UTF-8 encoded characters appearing in the string - representation of a DN or search filter may not be legal for URLs - (e.g. spaces) and MUST be escaped using the % method in [URI]. + A URI for a server implementing LDAP and accessible via [TCP]/[IP] + (v4 or v6) is written as an LDAP URL according to [LDAPURL]. + + SearchResultReference values which are LDAP URLs follow these rules: + + - The part of the LDAP URL MUST be present, with the new target + object name. The client uses this name when following the + reference. - Some servers (e.g. participating in distributed indexing) may - provide a different filter in a URL of a SearchResultReference. + provide a different filter in the LDAP URL. - - If the part of the URL is present, the client MUST use - this filter in its next request to progress this search, and if it - is not present the client MUST use the same filter as it used for - that search. + - If the part of the LDAP URL is present, the client uses + this filter in its next request to progress this Search, and if it + is not present the client uses the same filter as it used for that + Search. - If the originating search scope was singleLevel, the part - of the URL will be "base". + of the LDAP URL will be "base". - It is RECOMMENDED that the part be present to avoid - ambiguity. + ambiguity. In the absence of a part, the scope of the + original Search request is assumed. - - Other aspects of the new search request may be the same as or - different from the search request which generated the + - Other aspects of the new Search request may be the same as or + different from the Search request which generated the SearchResultReference. + -Sermersheim Internet-Draft - Expires Apr 2005 Page 25 +Sermersheim Internet-Draft - Expires Aug 2005 Page 26 + Lightweight Directory Access Protocol Version 3 - - The name of an unexplored subtree in a SearchResultReference need not be subordinate to the base object. Other kinds of URIs may be returned. The syntax and semantics of such URIs is left to future specifications. Clients may ignore URIs that they do not support. + + UTF-8 encoded characters appearing in the string representation of a + DN, search filter, or other fields of the referral value may not be + legal for URIs (e.g. spaces) and MUST be escaped using the % method + in [URI]. + 4.5.3.1. Examples For example, suppose the contacted server (hosta) holds the entry and the entry . It - knows that either LDAP-capable servers (hostb) or (hostc) hold + knows that both LDAP servers (hostb) and (hostc) hold (one is the master and the other server a shadow), and that LDAP-capable server (hostd) holds the subtree - . If a wholeSubtree search of + . If a wholeSubtree Search of is requested to the contacted server, it may return the following: @@ -1485,7 +1570,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 25 Client implementors should note that when following a SearchResultReference, additional SearchResultReference may be generated. Continuing the example, if the client contacted the server - (hostb) and issued the search for the subtree + (hostb) and issued the Search request for the subtree , the server might respond as follows: SearchResultEntry for OU=People,DC=Example,DC=NET @@ -1495,27 +1580,26 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 25 ldap://hostf/OU=Consultants,OU=People,DC=Example,DC=NET??sub } SearchResultDone (success) - Similarly, if a singleLevel search of is + Similarly, if a singleLevel Search of is requested to the contacted server, it may return the following: SearchResultEntry for CN=Manager,DC=Example,DC=NET SearchResultReference { ldap://hostb/OU=People,DC=Example,DC=NET??base ldap://hostc/OU=People,DC=Example,DC=NET??base } + +Sermersheim Internet-Draft - Expires Aug 2005 Page 27 + + Lightweight Directory Access Protocol Version 3 + SearchResultReference { ldap://hostd/OU=Roles,DC=Example,DC=NET??base } SearchResultDone (success) - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 26 - Lightweight Directory Access Protocol Version 3 - - If the contacted server does not hold the base object for the search, + If the contacted server does not hold the base object for the Search, but has knowledge of its possible location, then it may return a referral to the client. In this case, if the client requests a - subtree search of to hosta, the server returns a + subtree Search of to hosta, the server returns a SearchResultDone containing a referral. SearchResultDone (referral) { @@ -1524,7 +1608,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 26 4.6. Modify Operation - The Modify Operation allows a client to request that a modification + The Modify operation allows a client to request that a modification of an entry be performed on its behalf by a server. The Modify Request is defined as follows: @@ -1534,15 +1618,15 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 26 operation ENUMERATED { add (0), delete (1), - replace (2) }, + replace (2), + ... }, modification PartialAttribute } } Fields of the Modify Request are: - - object: The name of the object to be modified. The value of this - field contains the DN of the entry to be modified. The server - SHALL NOT perform any alias dereferencing in determining the - object to be modified. + - object: The value of this field contains the name of the entry to + be modified. The server SHALL NOT perform any alias dereferencing + in determining the object to be modified. - changes: A list of modifications to be performed on the entry. The entire list of modifications MUST be performed in the order they @@ -1561,16 +1645,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 26 add: add values listed to the modification attribute, creating the attribute if necessary; - delete: delete values listed from the modification attribute, - removing the entire attribute if no values are listed, or if - all current values of the attribute are listed for deletion; - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 27 +Sermersheim Internet-Draft - Expires Aug 2005 Page 28 + Lightweight Directory Access Protocol Version 3 + delete: delete values listed from the modification attribute. + If no values are listed, or if all current values of the + attribute are listed, the entire attribute is removed; + replace: replace all existing values of the modification attribute with the new values listed, creating the attribute if it did not already exist. A replace with no value will @@ -1595,15 +1679,21 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 27 been performed if the Modify Response received indicates any sort of error, and that all requested modifications have been performed if the Modify Response indicates successful completion of the Modify - Operation. The result of the modification is indeterminate if the - Modify Response is not received (e.g. the LDA exchange is terminated - or the Modify Operation is abandoned). - - The Modify Operation cannot be used to remove from an entry any of - its distinguished values, i.e. those values which form the entry's - relative distinguished name. An attempt to do so will result in the - server returning the notAllowedOnRDN result code. The Modify DN - Operation described in Section 4.9 is used to rename an entry. + operation. Whether the modification was applied or not cannot be + determined by the client if the Modify Response was not received + (e.g. the LDAP session was terminated or the Modify operation was + abandoned). + + Servers MUST ensure that entries conform to user and system schema + rules or other data model constraints. The Modify operation cannot be + used to remove from an entry any of its distinguished values, i.e. + those values which form the entry's relative distinguished name. An + attempt to do so will result in the server returning the + notAllowedOnRDN result code. The Modify DN operation described in + Section 4.9 is used to rename an entry. + + For attribute types which specify no equality matching, the rules in + Section 2.5.1 of [Models] are followed. Note that due to the simplifications made in LDAP, there is not a direct mapping of the changes in an LDAP ModifyRequest onto the @@ -1615,7 +1705,12 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 27 4.7. Add Operation - The Add Operation allows a client to request the addition of an entry + +Sermersheim Internet-Draft - Expires Aug 2005 Page 29 + + Lightweight Directory Access Protocol Version 3 + + The Add operation allows a client to request the addition of an entry into the Directory. The Add Request is defined as follows: AddRequest ::= [APPLICATION 8] SEQUENCE { @@ -1625,22 +1720,22 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 27 AttributeList ::= SEQUENCE OF attribute Attribute Fields of the Add Request are: - -Sermersheim Internet-Draft - Expires Apr 2005 Page 28 - Lightweight Directory Access Protocol Version 3 - - entry: the name of the entry to be added. The server SHALL NOT dereference any aliases in locating the entry to be added. - attributes: the list of attributes that, along with those from the RDN, make up the content of the entry being added. Clients MAY or - MAY NOT include the RDN attribute in this list. Clients MUST - include the 'objectClass' attribute, and values of any mandatory - attributes of the listed object classes. Clients MUST NOT supply - NO-USER-MODIFICATION attributes such as the createTimestamp or - creatorsName attributes, since the server maintains these - automatically. + MAY NOT include the RDN attribute(s) in this list. Clients MUST + NOT supply NO-USER-MODIFICATION attributes such as the + createTimestamp or creatorsName attributes, since the server + maintains these automatically. + + Servers MUST ensure that entries conform to user and system schema + rules or other data model constraints. For attribute types which + specify no equality matching, the rules in Section 2.5.1 of [Models] + are followed (this applies to the naming attribute in addition to any + multi-valued attributes being added). The entry named in the entry field of the AddRequest MUST NOT exist for the AddRequest to succeed. The immediate superior (parent) of an @@ -1650,13 +1745,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 28 exist, then the server would return the noSuchObject result code with the matchedDN field containing . - Server implementations SHOULD NOT restrict where entries can be - located in the Directory unless DIT structure rules are in place. - Some servers allow the administrator to restrict the classes of - entries which can be added to the Directory. - Upon receipt of an Add Request, a server will attempt to add the - requested entry. The result of the add attempt will be returned to + requested entry. The result of the Add attempt will be returned to the client in the Add Response, defined as follows: AddResponse ::= [APPLICATION 9] LDAPResult @@ -1667,11 +1757,18 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 28 4.8. Delete Operation - The Delete Operation allows a client to request the removal of an + The Delete operation allows a client to request the removal of an entry from the Directory. The Delete Request is defined as follows: DelRequest ::= [APPLICATION 10] LDAPDN + + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 30 + + Lightweight Directory Access Protocol Version 3 + The Delete Request consists of the name of the entry to be deleted. The server SHALL NOT dereference aliases while resolving the name of the target entry to be removed. @@ -1683,16 +1780,12 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 28 the entry removal requested and return the result in the Delete Response defined as follows: - -Sermersheim Internet-Draft - Expires Apr 2005 Page 29 - Lightweight Directory Access Protocol Version 3 - DelResponse ::= [APPLICATION 11] LDAPResult 4.9. Modify DN Operation - The Modify DN Operation allows a client to change the Relative + The Modify DN operation allows a client to change the Relative Distinguished Name (RDN) of an entry in the Directory, and/or to move a subtree of entries to a new location in the Directory. The Modify DN Request is defined as follows: @@ -1708,12 +1801,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 29 - entry: the name of the entry to be changed. This entry may or may not have subordinate entries. - - newrdn: the new RDN of the entry. If the operation moves the entry - to a new superior without changing its RDN, the value of the old - RDN is supplied for this parameter. - Attribute values of the new RDN not matching any attribute value - of the entry are added to the entry and an appropriate error is - returned if this fails. + - newrdn: the new RDN of the entry. The value of the old RDN is + supplied when moving the entry to a new superior without changing + its RDN. Attribute values of the new RDN not matching any + attribute value of the entry are added to the entry and an + appropriate error is returned if this fails. - deleteoldrdn: a boolean field that controls whether the old RDN attribute values are to be retained as attributes of the entry, or @@ -1731,6 +1823,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 29 defined as follows: ModifyDNResponse ::= [APPLICATION 13] LDAPResult + +Sermersheim Internet-Draft - Expires Aug 2005 Page 31 + + Lightweight Directory Access Protocol Version 3 + For example, if the entry named in the entry field was , the newrdn field was , and the @@ -1739,12 +1836,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 29 already an entry with that name, the operation would fail with the entryAlreadyExists result code. + Servers MUST ensure that entries conform to user and system schema + rules or other data model constraints. For attribute types which + specify no equality matching, the rules in Section 2.5.1 of [Models] + are followed (this pertains to newrdn and deleteoldrdn). + The object named in newSuperior MUST exist. For example, if the client attempted to add , the - -Sermersheim Internet-Draft - Expires Apr 2005 Page 30 - Lightweight Directory Access Protocol Version 3 - entry did not exist, and the entry did exist, then the server would return the noSuchObject result code with the matchedDN field containing . @@ -1752,10 +1850,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 30 If the deleteoldrdn field is TRUE, the attribute values forming the old RDN but not the new RDN are deleted from the entry. If the deleteoldrdn field is FALSE, the attribute values forming the old RDN - will be retained as non-distinguished attribute values of the entry. - The server MUST fail the operation and return an error in the result - code if the setting of the deleteoldrdn field would cause a schema - inconsistency in the entry. + will be retained as non-distinguished attribute values of the entry. Note that X.500 restricts the ModifyDN operation to only affect entries that are contained within a single server. If the LDAP server @@ -1768,7 +1863,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 30 4.10. Compare Operation - The Compare Operation allows a client to compare an assertion value + The Compare operation allows a client to compare an assertion value with the values of a particular attribute in a particular entry in the Directory. The Compare Request is defined as follows: @@ -1787,23 +1882,22 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 30 the requested comparison and return the result in the Compare Response, defined as follows: - CompareResponse ::= [APPLICATION 15] LDAPResult - - The resultCode field is set to compareTrue, compareFalse, or an - appropriate error. compareTrue indicates that the assertion value in - the ava field matches a value of the attribute or subtype according - to the attribute's EQUALITY matching rule. compareFalse indicates - that the assertion value in the ava field and the values of the - attribute or subtype did not match. Other result codes indicate - either that the result of the comparison was Undefined (Section - 4.5.1), or that some error occurred. - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 31 +Sermersheim Internet-Draft - Expires Aug 2005 Page 32 + Lightweight Directory Access Protocol Version 3 + CompareResponse ::= [APPLICATION 15] LDAPResult + + The resultCode is set to compareTrue, compareFalse, or an appropriate + error. compareTrue indicates that the assertion value in the ava + field matches a value of the attribute or subtype according to the + attribute's EQUALITY matching rule. compareFalse indicates that the + assertion value in the ava field and the values of the attribute or + subtype did not match. Other result codes indicate either that the + result of the comparison was Undefined (Section 4.5.1), or that some + error occurred. + Note that some directory systems may establish access controls which permit the values of certain attributes (such as userPassword) to be compared but not interrogated by other means. @@ -1811,16 +1905,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 31 4.11. Abandon Operation - The function of the Abandon Operation is to allow a client to request + The function of the Abandon operation is to allow a client to request that the server abandon an uncompleted operation. The Abandon Request is defined as follows: AbandonRequest ::= [APPLICATION 16] MessageID - The MessageID is that of an operation which was requested earlier in - this LDAP exchange. The abandon request itself has its own MessageID. - This is distinct from the MessageID of the earlier operation being - abandoned. + The MessageID is that of an operation which was requested earlier at + this LDAP message layer. The Abandon request itself has its own + MessageID. This is distinct from the MessageID of the earlier + operation being abandoned. There is no response defined in the Abandon operation. Upon receipt of an AbandonRequest, the server MAY abandon the operation identified @@ -1832,43 +1926,43 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 31 Abandon, Bind, Unbind, and StartTLS operations cannot be abandoned. In the event that a server receives an Abandon Request on a Search - Operation in the midst of transmitting responses to the search, that + operation in the midst of transmitting responses to the Search, that server MUST cease transmitting entry responses to the abandoned - request immediately, and MUST NOT send the SearchResponseDone. Of + request immediately, and MUST NOT send the SearchResultDone. Of course, the server MUST ensure that only properly encoded LDAPMessage PDUs are transmitted. The ability to abandon other (particularly update) operations is at the discretion of the server. - Clients should not send abandon requests for the same operation + Clients should not send Abandon requests for the same operation multiple times, and MUST also be prepared to receive results from operations it has abandoned (since these may have been in transit - when the abandon was requested, or are not able to be abandoned). + when the Abandon was requested, or are not able to be abandoned). - Servers MUST discard abandon requests for message IDs they do not + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 33 + + Lightweight Directory Access Protocol Version 3 + + Servers MUST discard Abandon requests for message IDs they do not recognize, for operations which cannot be abandoned, and for operations which have already been abandoned. 4.12. Extended Operation - The extended operation allows additional operations to be defined for - services not already available in the protocol. For example, to add + The Extended operation allows additional operations to be defined for + services not already available in the protocol. For example, to Add operations to install transport layer security (see Section 4.14). - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 32 - Lightweight Directory Access Protocol Version 3 - - The extended operation allows clients to make requests and receive + The Extended operation allows clients to make requests and receive responses with predefined syntaxes and semantics. These may be defined in RFCs or be private to particular implementations. - Each extended operation consists of an extended request and an - extended response. + Each Extended operation consists of an Extended request and an + Extended response. ExtendedRequest ::= [APPLICATION 23] SEQUENCE { requestName [0] LDAPOID, @@ -1892,24 +1986,31 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 32 responseValue) is implicitly known and associated with the request by the messageID. - If the extended operation associated with the requestName is not + If the Extended operation associated with the requestName is not supported by the server, the server MUST NOT provide a responseName - nor a responseValue and MUST return a resultCode of protocolError. + nor a responseValue and MUST return with resultCode set to + protocolError. The requestValue and responseValue fields contain any information associated with the operation. The format of these fields is defined - by the specification of the extended operation. Implementations MUST + by the specification of the Extended operation. Implementations MUST be prepared to handle arbitrary contents of these fields, including zero bytes. Values that are defined in terms of ASN.1 and BER encoded - according to Section 5.2, also follow the extensibility rules in + according to Section 5.1, also follow the extensibility rules in Section 4. + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 34 + + Lightweight Directory Access Protocol Version 3 + Servers list the requestName of Extended Requests they recognize in the 'supportedExtension' attribute in the root DSE (Section 5.1 of [Models]). Extended operations may be specified in other documents. The - specification of an extended operation consists of: + specification of an Extended operation consists of: - the OBJECT IDENTIFIER assigned to the requestName, @@ -1917,10 +2018,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 32 that the same OBJECT IDENTIFIER my be used for both the requestName and responseName), - -Sermersheim Internet-Draft - Expires Apr 2005 Page 33 - Lightweight Directory Access Protocol Version 3 - - the format of the contents of the requestValue and responseValue (if any), and @@ -1930,18 +2027,18 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 33 4.13. IntermediateResponse Message While the Search operation provides a mechanism to return multiple - response messages for a single search request, other operations, by + response messages for a single Search request, other operations, by nature, do not provide for multiple response messages. The IntermediateResponse message provides a general mechanism for defining single-request/multiple-response operations in LDAP. This - message is intended to be used in conjunction with the extended + message is intended to be used in conjunction with the Extended operation to define new single-request/multiple-response operations or in conjunction with a control when extending existing LDAP - operations in a way that requires them to return intermediate + operations in a way that requires them to return Intermediate response information. - It is intended that the definitions and descriptions of extended + It is intended that the definitions and descriptions of Extended operations and controls that make use of the IntermediateResponse message will define the circumstances when an IntermediateResponse message can be sent by a server and the associated meaning of an @@ -1953,15 +2050,20 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 33 IntermediateResponse messages SHALL NOT be returned to the client unless the client issues a request that specifically solicits their - return. This document defines two forms of solicitation: extended + return. This document defines two forms of solicitation: Extended operation and request control. IntermediateResponse messages are specified in documents describing the manner in which they are - solicited (i.e. in the extended operation or request control + solicited (i.e. in the Extended operation or request control specification that uses them). These specifications include: - the OBJECT IDENTIFIER (if any) assigned to the responseName, - - the format of the contents of the responseValue, and + - the format of the contents of the responseValue (if any), and + +Sermersheim Internet-Draft - Expires Aug 2005 Page 35 + + Lightweight Directory Access Protocol Version 3 + - the semantics associated with the IntermediateResponse message. @@ -1975,10 +2077,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 33 4.13.1. Usage with LDAP ExtendedRequest and ExtendedResponse - -Sermersheim Internet-Draft - Expires Apr 2005 Page 34 - Lightweight Directory Access Protocol Version 3 - A single-request/multiple-response operation may be defined using a single ExtendedRequest message to solicit zero or more @@ -2002,15 +2100,15 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 34 included in a request for any LDAP operation or - one or more controls using IntermediateResponse messages are - included in a request with an LDAP extended operation that uses + included in a request with an LDAP Extended operation that uses IntermediateResponse messages. 4.14. StartTLS Operation - The Start Transport Layer Security (StartTLS) operationÆs purpose is + The Start Transport Layer Security (StartTLS) operation's purpose is to initiate installation of a TLS layer. The StartTLS operation is - defined using the extended operation mechanism described in Section + defined using the Extended operation mechanism described in Section 4.12. @@ -2018,24 +2116,27 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 34 A client requests TLS establishment by transmitting a StartTLS request PDU to the server. The StartTLS request is defined in terms + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 36 + + Lightweight Directory Access Protocol Version 3 + of an ExtendedRequest. The requestName is "1.3.6.1.4.1.1466.20037", and the requestValue field is always absent. - The client MUST NOT send any PDUs on this LDAP exchange following - this request until it receives a StartTLS extended response and, in - the case of a successful response, completes TLS negotiations. + The client MUST NOT send any PDUs at this LDAP message layer + following this request until it receives a StartTLS Extended response + and, in the case of a successful response, completes TLS + negotiations. - Sequencing problems (particularly those detailed in Section 3.1.1 of - [AuthMeth] result in an operationsError being returned in the - resultCode. + Detected sequencing problems (particularly those detailed in Section + 3.1.1 of [AuthMeth]) result in the resultCode being set to + operationsError. If the server does not support TLS (whether by design or by current - configuration), it returns the protocolError resultCode as described - in Section 4.12. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 35 - Lightweight Directory Access Protocol Version 3 - + configuration), it returns with the resultCode set to protocolError + as described in Section 4.12. 4.14.2. StartTLS Response @@ -2045,65 +2146,52 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 35 responseName, if present, is also "1.3.6.1.4.1.1466.20037". The responseValue is absent. - If the server is willing and able to negotiate TLS, it returns a - success resultCode. Refer to Section 4 of [AuthMeth] for details. + If the server is willing and able to negotiate TLS, it returns with + the resultCode set to success. Refer to Section 4 of [AuthMeth] for + details. If the server is otherwise unwilling or unable to perform this operation, the server is to return an appropriate result code indicating the nature of the problem. For example, if the TLS - subsystem is not presently available, the server may return indicate - so by returning the unavailable resultCode. + subsystem is not presently available, the server may indicate so by + returning with the resultCode set to unavailable. 4.14.3. Removal of the TLS Layer - Two forms of TLS layer removal -- graceful and abrupt -- are - provided. These do not involve LDAP PDUs, but are preformed at the - underlying layers. - - If the connection is closed, uncompleted operations are handled as - specified in Section 5.1. - - -4.14.3.1. Graceful Removal - Either the client or server MAY remove the TLS layer and leave the - LDAP exchange intact by sending and receiving a TLS closure alert. + LDAP message layer intact by sending and receiving a TLS closure + alert. The initiating protocol peer sends the TLS closure alert. If it - wishes to leave the LDAP exchange intact, it then MUST cease to send - further PDUs and MUST ignore any received LDAP PDUs until it receives - a TLS closure alert from the other peer. + wishes to leave the LDAP message layer intact, it then MUST cease to + send further PDUs and MUST ignore any received LDAP PDUs until it + receives a TLS closure alert from the other peer. Once the initiating protocol peer receives a TLS closure alert from the other peer it MAY send and receive LDAP PDUs. When a protocol peer receives the initial TLS closure alert, it may - choose to allow the LDAP exchange to remain intact. In this case, it - MUST immediately transmit a TLS closure alert. Following this, it MAY - send and receive LDAP PDUs. + choose to allow the LDAP message layer to remain intact. In this + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 37 + + Lightweight Directory Access Protocol Version 3 + + case, it MUST immediately transmit a TLS closure alert. Following + this, it MAY send and receive LDAP PDUs. - Protocol peers MAY close the connection after sending or receiving a - TLS closure alert. + Protocol peers MAY terminate the LDAP session after sending or + receiving a TLS closure alert. After the TLS layer has been removed, the server MUST NOT send responses to any request message received before the TLS closure - -Sermersheim Internet-Draft - Expires Apr 2005 Page 36 - Lightweight Directory Access Protocol Version 3 - alert. Thus, clients wishing to receive responses to messages sent while the TLS layer is intact MUST wait for those message responses before sending the TLS closure alert. -4.14.3.2. Abrupt Removal - - Either the client or server MAY abruptly remove the TLS layer by - closing the connection. In this circumstance, a server MAY send the - client a Notice of Disconnection before closing the connection. - - 5. Protocol Encoding, Connection, and Transfer This protocol is designed to run over connection-oriented, reliable @@ -2111,44 +2199,46 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 36 units), with each octet and each bit being significant. One underlying service, LDAP over TCP, is defined in Section - 5.3. This service is generally applicable to applications providing + 5.2. This service is generally applicable to applications providing or consuming X.500-based directory services on the Internet. This specification was generally written with the TCP mapping in mind. Specifications detailing other mappings may encounter various obstacles. Implementations of LDAP over TCP MUST implement the mapping as - described in Section 5.3. + described in Section 5.2. This table illustrates the relationship between the different layers involved in an exchange between two protocol peers: - +---------------+ - | LDAP exchange | - +---------------+ > LDAP PDUs - +---------------+ < data - | SASL layer | - +---------------+ > SASL-protected data - +---------------+ < data - | TLS layer | - Application +---------------+ > TLS-protected data - ------------+---------------+ < data - Transport | connection | - +---------------+ + +----------------------+ + | LDAP message layer | + +----------------------+ > LDAP PDUs + +----------------------+ < data + | SASL layer | + +----------------------+ > SASL-protected data + +----------------------+ < data + | TLS layer | + Application +----------------------+ > TLS-protected data + ------------+----------------------+ < data + Transport | transport connection | + +----------------------+ -5.2. Protocol Encoding +5.1. Protocol Encoding The protocol elements of LDAP SHALL be encoded for exchange using the Basic Encoding Rules [BER] of [ASN.1] with the following restrictions: - Only the definite form of length encoding is used. - + -Sermersheim Internet-Draft - Expires Apr 2005 Page 37 +Sermersheim Internet-Draft - Expires Aug 2005 Page 38 + Lightweight Directory Access Protocol Version 3 + - OCTET STRING values are encoded in the primitive form only. - If the value of a BOOLEAN type is true, the encoding of the value @@ -2166,10 +2256,10 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 37 stated. -5.3. Transmission Control Protocol (TCP) +5.2. Transmission Control Protocol (TCP) The encoded LDAPMessage PDUs are mapped directly onto the [TCP] - bytestream using the BER-based encoding described in Section 5.2. It + bytestream using the BER-based encoding described in Section 5.1. It is recommended that server implementations running over the TCP provide a protocol listener on the Internet Assigned Numbers Authority (IANA)-assigned LDAP port, 389 [PortReg]. Servers may @@ -2177,13 +2267,36 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 37 support contacting servers on any valid TCP port. +5.3. Termination of the LDAP session + + Termination of the LDAP session is typically initiated by the client + sending an UnbindRequst (Section 4.3), or by the server sending a + Notice of Disconnection (Section 4.4.1). In these cases each protocol + peer gracefully terminates the LDAP session by ceasing exchanges at + the LDAP message layer, tearing down any SASL layer, tearing down any + TLS layer, and closing the transport connection. + + A protocol peer may determine that the continuation of any + communication would be pernicious, and in this case may abruptly + terminate the session by ceasing communication and closing the + transport connection. + + In either case, when the LDAP session is terminated, uncompleted + operations are handled as specified in Section 3.1. + + 6. Security Considerations This version of the protocol provides facilities for simple authentication using a cleartext password, as well as any [SASL] - mechanism. Installing SASL layers can provide integrity and other - data security services. + mechanism. Installing SASL and/or TLS layers can provide integrity + and other data security services. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 39 + + Lightweight Directory Access Protocol Version 3 + It is also permitted that the server can return its credentials to the client, if it chooses to do so. @@ -2199,21 +2312,17 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 37 It should be noted that SASL authentication exchanges do not provide data confidentiality nor integrity protection for the version or name - fields of the bind request nor the resultCode, diagnosticMessage, or - referral fields of the bind response nor of any information contained - in controls attached to bind request or responses. Thus information + fields of the BindRequest nor the resultCode, diagnosticMessage, or + referral fields of the BindResponse nor of any information contained + in controls attached to Bind requests or responses. Thus information contained in these fields SHOULD NOT be relied on unless otherwise - -Sermersheim Internet-Draft - Expires Apr 2005 Page 38 - Lightweight Directory Access Protocol Version 3 - protected (such as by establishing protections at the transport layer). Server implementors should plan for the possibility of (protocol or external) events which alter the information used to establish security factors (e.g., credentials, authorization identities, access - controls) during the course of the LDAP exchange, and even during the + controls) during the course of the LDAP session, and even during the performance of a particular operation, and should take steps to avoid insecure side effects of these changes. The ways in which these issues are addressed are application and/or implementation specific. @@ -2222,11 +2331,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 38 MUST ensure that access controls are maintained if that information is to be provided to multiple clients, since servers may have access control policies which prevent the return of entries or attributes in - search results except to particular authenticated clients. For + Search results except to particular authenticated clients. For example, caches could serve result information only to the client whose request caused it to be in the cache. - Servers may return referrals or search result references which + Servers may return referrals or Search result references which redirect clients to peer servers. It is possible for a rogue application to inject such referrals into the data stream in an attempt to redirect a client to a rogue server. Clients are advised @@ -2236,11 +2345,17 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 38 The matchedDN and diagnosticMessage fields, as well as some resultCode values (e.g., attributeOrValueExists and - entryAlreadyExists), could disclose the presence the specific data in - the directory which is subject to access and other administrative - controls. Server implementations should restrict access to protected - information equally under both normal and error conditions. + entryAlreadyExists), could disclose the presence or absence of + specific data in the directory which is subject to access and other + administrative controls. Server implementations should restrict + access to protected information equally under both normal and error + conditions. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 40 + + Lightweight Directory Access Protocol Version 3 + Protocol peers MUST be prepared to handle invalid and arbitrary length protocol encodings. Invalid protocol encodings include: BER encoding exceptions, format string and UTF-8 encoding exceptions, @@ -2249,6 +2364,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 38 excellent examples of these exceptions and test cases used to discover flaws. + In the event that a protocol peer senses an attack which in its + nature could cause damage due to further communication at any layer + in the LDAP session, the protocol peer should abruptly terminate the + LDAP session as described in Section 5.3. + 7. Acknowledgements @@ -2261,10 +2381,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 38 It is also based on RFC 3771 by Roger Harrison, and Kurt Zeilenga. RFC 3771 was an individual submission to the IETF. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 39 - Lightweight Directory Access Protocol Version 3 - This document is a product of the IETF LDAPBIS Working Group. Significant contributors of technical review and content include Kurt Zeilenga, Steven Legg, and Hallvard Furuseth. @@ -2292,6 +2408,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 39 [IP] Postel, J., "Internet Protocol", STD5 and RFC 791, September 1981 + + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 41 + + Lightweight Directory Access Protocol Version 3 + [ISO10646] Universal Multiple-Octet Coded Character Set (UCS) - Architecture and Basic Multilingual Plane, ISO/IEC 10646-1 : 1993. @@ -2318,12 +2441,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 39 [SASL] Melnikov, A., "Simple Authentication and Security Layer", draft-ietf-sasl-rfc2222bis-xx.txt (a work in progress). - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 40 - Lightweight Directory Access Protocol Version 3 - [SASLPrep] Zeilenga, K., "Stringprep profile for user names and passwords", draft-ietf-sasl-saslprep-xx.txt, (a work in progress). @@ -2350,6 +2467,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 40 "Unicode Standard Annex #28: Unicode 3.2" (http://www.unicode.org/reports/tr28/). + + + +Sermersheim Internet-Draft - Expires Aug 2005 Page 42 + + Lightweight Directory Access Protocol Version 3 + [URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. @@ -2376,13 +2500,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 40 , August 2000. - - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 41 - Lightweight Directory Access Protocol Version 3 - [PROTOS-LDAP] University of Oulu, "PROTOS Test-Suite: c06-ldapv3" @@ -2401,7 +2518,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 41 It is requested that the IANA update the LDAP Protocol Mechanism registry to indicate that this document and [AuthMeth] provides the definitive technical specification for the StartTLS - (1.3.6.1.4.1.1466.20037) extended operation. + (1.3.6.1.4.1.1466.20037) Extended operation. It is requested that the IANA update the occurrence of "RFC XXXX" in Appendix B with this RFC number at publication. @@ -2411,6 +2528,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 41 Jim Sermersheim Novell, Inc. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 43 + + Lightweight Directory Access Protocol Version 3 + 1800 South Novell Place Provo, Utah 84606, USA jimse@novell.com @@ -2435,11 +2557,39 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 41 + + + + + + + + + + + + + + + + + + + + + + + + + + + -Sermersheim Internet-Draft - Expires Apr 2005 Page 42 +Sermersheim Internet-Draft - Expires Aug 2005 Page 44 + Lightweight Directory Access Protocol Version 3 Appendix A - LDAP Result Codes @@ -2452,6 +2602,9 @@ Appendix A - LDAP Result Codes [LDAPIANA]. Client implementations SHALL treat any result code which they do not recognize as an unknown error condition. + Servers may substitute some result codes due to access controls which + prevent their disclosure. + A.1 Non-Error Result Codes @@ -2468,7 +2621,7 @@ A.1 Non-Error Result Codes result codes). The referral and saslBindInProgress result codes indicate the client - is required to take additional action to complete the operation. + needs to take additional action to complete the operation. A.2 Result Codes @@ -2477,7 +2630,7 @@ A.2 Result Codes success (0) Indicates the successful completion of an operation. Note: - this code is not used with the compare operation. See + this code is not used with the Compare operation. See compareFalse (5) and compareTrue (6). operationsError (1) @@ -2491,19 +2644,21 @@ A.2 Result Codes protocolError (2) Indicates the server received data which is not well-formed. - For bind operation only, this code is also used to indicate - that the server does not support the requested protocol - version. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 43 +Sermersheim Internet-Draft - Expires Aug 2005 Page 45 + Lightweight Directory Access Protocol Version 3 - For extended operations only, this code indicates that the - server does not support (by design or configuration) the - extended operation associated with the requestName. + For Bind operation only, this code is also used to indicate + that the server does not support the requested protocol + version. + + For Extended operations only, this code is also used to + indicate that the server does not support (by design or + configuration) the Extended operation associated with the + requestName. For request operations specifying multiple controls, this may be used to indicate that the server cannot ignore the order @@ -2519,24 +2674,26 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 43 exceeded before the operation could be completed. compareFalse (5) - Indicates that the compare operation has successfully + Indicates that the Compare operation has successfully completed and the assertion has evaluated to FALSE or Undefined. compareTrue (6) - Indicates that the compare operation has successfully + Indicates that the Compare operation has successfully completed and the assertion has evaluated to TRUE. authMethodNotSupported (7) Indicates that the authentication method or mechanism is not supported. - strongAuthRequired (8) - Indicates that the server has detected that an established - security association between the client and server has - unexpectedly failed or been compromised, or that the server - now requires the client to authenticate using a strong(er) - mechanism. + strongerAuthRequired (8) + Indicates the server requires strong(er) authentication in + order to complete the operation. + + When used with the Notice of Disconnection operation, this + code indicates that the server has detected that an + established security association between the client and + server has unexpectedly failed or been compromised. referral (10) Indicates that a referral needs to be chased to complete the @@ -2548,18 +2705,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 43 unavailableCriticalExtension (12) Indicates a critical control is unrecognized (see Section 4.1.11). + +Sermersheim Internet-Draft - Expires Aug 2005 Page 46 + + Lightweight Directory Access Protocol Version 3 + confidentialityRequired (13) Indicates that data confidentiality protections are required. saslBindInProgress (14) - - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 44 - Lightweight Directory Access Protocol Version 3 - Indicates the server requires the client to send a new bind request, with the same SASL mechanism, to continue the authentication process (see Section 4.2). @@ -2609,15 +2764,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 44 values which do not conform to the syntax of the attribute's type. + +Sermersheim Internet-Draft - Expires Aug 2005 Page 47 + + Lightweight Directory Access Protocol Version 3 + aliasDereferencingProblem (36) Indicates that a problem occurred while dereferencing an alias. Typically an alias was encountered in a situation where it was not allowed or where access was denied. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 45 - Lightweight Directory Access Protocol Version 3 - inappropriateAuthentication (48) Indicates the server requires the client which had attempted to bind anonymously or without supplying credentials to @@ -2667,15 +2823,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 45 or renamed) as the target entry already exists. objectClassModsProhibited (69) + +Sermersheim Internet-Draft - Expires Aug 2005 Page 48 + + Lightweight Directory Access Protocol Version 3 + Indicates that an attempt to modify the object class(es) of an entry's 'objectClass' attribute is prohibited. For example, this code is returned when a client attempts to modify the structural object class of an entry. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 46 - Lightweight Directory Access Protocol Version 3 - affectsMultipleDSAs (71) Indicates that the operation cannot be performed as it would @@ -2718,12 +2875,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 46 - - - - - - @@ -2732,7 +2883,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 46 -Sermersheim Internet-Draft - Expires Apr 2005 Page 47 +Sermersheim Internet-Draft - Expires Aug 2005 Page 49 + Lightweight Directory Access Protocol Version 3 Appendix B - Complete ASN.1 Definition @@ -2790,7 +2942,8 @@ Appendix B - Complete ASN.1 Definition RelativeLDAPDN ::= LDAPString -- Constrained to -Sermersheim Internet-Draft - Expires Apr 2005 Page 48 +Sermersheim Internet-Draft - Expires Aug 2005 Page 50 + Lightweight Directory Access Protocol Version 3 -- [LDAPDN] @@ -2827,7 +2980,7 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 48 compareFalse (5), compareTrue (6), authMethodNotSupported (7), - strongAuthRequired (8), + strongerAuthRequired (8), -- 9 reserved -- referral (10), adminLimitExceeded (11), @@ -2848,7 +3001,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 48 aliasDereferencingProblem (36), -- 37-47 unused -- -Sermersheim Internet-Draft - Expires Apr 2005 Page 49 +Sermersheim Internet-Draft - Expires Aug 2005 Page 51 + Lightweight Directory Access Protocol Version 3 inappropriateAuthentication (48), @@ -2906,7 +3060,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 49 serverSaslCreds [7] OCTET STRING OPTIONAL } -Sermersheim Internet-Draft - Expires Apr 2005 Page 50 +Sermersheim Internet-Draft - Expires Aug 2005 Page 52 + Lightweight Directory Access Protocol Version 3 UnbindRequest ::= [APPLICATION 2] NULL @@ -2916,7 +3071,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 50 scope ENUMERATED { baseObject (0), singleLevel (1), - wholeSubtree (2) }, + wholeSubtree (2), + ... }, derefAliases ENUMERATED { neverDerefAliases (0), derefInSearching (1), @@ -2930,11 +3086,11 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 50 AttributeSelection ::= SEQUENCE OF selector LDAPString -- The LDAPString is constrained to - -- in Section 4.5.1 + -- in Section 4.5.1.7 Filter ::= CHOICE { - and [0] SET OF filter Filter, - or [1] SET OF filter Filter, + 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, @@ -2942,16 +3098,16 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 50 lessOrEqual [6] AttributeValueAssertion, present [7] AttributeDescription, approxMatch [8] AttributeValueAssertion, - extensibleMatch [9] MatchingRuleAssertion } + extensibleMatch [9] MatchingRuleAssertion, + ... } SubstringFilter ::= SEQUENCE { type AttributeDescription, - -- at least one must be present, - -- initial and final can occur at most once substrings SEQUENCE SIZE (1..MAX) OF substring CHOICE { - initial [0] AssertionValue, + initial [0] AssertionValue, -- can occur at most once any [1] AssertionValue, - final [2] AssertionValue } } + final [2] AssertionValue } -- can occur at most once + } MatchingRuleAssertion ::= SEQUENCE { matchingRule [1] MatchingRuleId OPTIONAL, @@ -2962,11 +3118,12 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 50 SearchResultEntry ::= [APPLICATION 4] SEQUENCE { objectName LDAPDN, attributes PartialAttributeList } - -Sermersheim Internet-Draft - Expires Apr 2005 Page 51 +Sermersheim Internet-Draft - Expires Aug 2005 Page 53 + Lightweight Directory Access Protocol Version 3 + PartialAttributeList ::= SEQUENCE OF partialAttribute PartialAttribute @@ -2981,7 +3138,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 51 operation ENUMERATED { add (0), delete (1), - replace (2) }, + replace (2), + ... }, modification PartialAttribute } } ModifyResponse ::= [APPLICATION 7] LDAPResult @@ -3019,12 +3177,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 51 requestValue [1] OCTET STRING OPTIONAL } ExtendedResponse ::= [APPLICATION 24] SEQUENCE { - COMPONENTS OF LDAPResult, - responseName [10] LDAPOID OPTIONAL, -Sermersheim Internet-Draft - Expires Apr 2005 Page 52 +Sermersheim Internet-Draft - Expires Aug 2005 Page 54 + Lightweight Directory Access Protocol Version 3 + COMPONENTS OF LDAPResult, + responseName [10] LDAPOID OPTIONAL, responseValue [11] OCTET STRING OPTIONAL } IntermediateResponse ::= [APPLICATION 25] SEQUENCE { @@ -3073,23 +3232,21 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 52 - - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 53 +Sermersheim Internet-Draft - Expires Aug 2005 Page 55 + Lightweight Directory Access Protocol Version 3 Appendix C - Changes This appendix is non-normative. - This appendix summarizes substantive changes made to RFC 2251 and RFC - 2830. + This appendix summarizes substantive changes made to RFC 2251, RFC + 2830, and RFC 3771. C.1 Changes made to RFC 2251: @@ -3100,7 +3257,7 @@ C.1 Changes made to RFC 2251: sections. -C.1.1 Section 1 +C.1.1 Section 1 (Status of this Memo) - Removed IESG note. Post publication of RFC 2251, mandatory LDAP authentication mechanisms have been standardized which are @@ -3108,52 +3265,52 @@ C.1.1 Section 1 mechanisms. -C.1.2 Section 3.1 and others +C.1.2 Section 3.1 (Protocol Model) and others - Removed notes giving history between LDAP v1, v2 and v3. Instead, added sufficient language so that this document can stand on its own. -C.1.3 Section 4 +C.1.3 Section 4 (Elements of Protocol) - Clarified where the extensibility features of ASN.1 apply to the - protocol. This change also affected various ASN.1 types. + protocol. This change affected various ASN.1 types by the + inclusion of ellipses (...) to certain elements. - Removed the requirement that servers which implement version 3 or later MUST provide the 'supportedLDAPVersion' attribute. This statement provided no interoperability advantages. -C.1.4 Section 4.1.1 +C.1.4 Section 4.1.1 (Message Envelope) - There was a mandatory requirement for the server to return a - Notice of Disconnection and drop the connection when a PDU is - malformed in a certain way. This has been clarified such that the - server SHOULD return the Notice of Disconnection, and MUST drop - the connection. + Notice of Disconnection and drop the transport connection when a + PDU is malformed in a certain way. This has been updated such that + the server SHOULD return the Notice of Disconnection, and MUST + terminate the LDAP Session. -C.1.5 Section 4.1.1.1 +C.1.5 Section 4.1.1.1 (Message ID) - - Clarified that the messageID of requests MUST be non-zero. - - - + - Required that the messageID of requests MUST be non-zero as the + zero is reserved for Notice of Disconnection. -Sermersheim Internet-Draft - Expires Apr 2005 Page 54 +Sermersheim Internet-Draft - Expires Aug 2005 Page 56 + Lightweight Directory Access Protocol Version 3 - - Clarified when it is and isn't appropriate to return an already + - Specified when it is and isn't appropriate to return an already used message id. RFC 2251 accidentally imposed synchronous server behavior in its wording of this. -C.1.6 Section 4.1.2 +C.1.6 Section 4.1.2 (String Types) - Stated that LDAPOID is constrained to from [Models]. -C.1.7 Section 4.1.5.1 and others +C.1.7 Section 4.1.5.1 (Binary Option) and others - Removed the Binary Option from the specification. There are numerous interoperability problems associated with this method of @@ -3161,22 +3318,25 @@ C.1.7 Section 4.1.5.1 and others replacement is ongoing. -C.1.8 Section 4.1.8 +C.1.8 Section 4.1.8 (Attribute) - Combined the definitions of PartialAttribute and Attribute here, and defined Attribute in terms of PartialAttribute. -C.1.9 Section 4.1.10 +C.1.9 Section 4.1.10 (Result Message) - Renamed "errorMessage" to "diagnosticMessage" as it is allowed to be sent for non-error results. - Moved some language into Appendix A, and refer the reader there. - Allowed matchedDN to be present for other result codes than those listed in RFC 2251. + - renamed the code "strongAuthRequired" to "strongerAuthRequired" to + clarify that this code may often be returned to indicate that a + stronger authentication is needed to perform a given operation. -C.1.10 Section 4.1.11 +C.1.10 Section 4.1.11 (Referral) - Defined referrals in terms of URIs rather than URLs. - Removed the requirement that all referral URIs MUST be equally @@ -3185,23 +3345,25 @@ C.1.10 Section 4.1.11 - Added the requirement that clients MUST NOT loop between servers. - Clarified the instructions for using LDAPURLs in referrals, and in doing so added a recommendation that the scope part be present. + - Removed imperatives which required clients to use URLs in specific + ways to progress an operation. These did nothing for + interoperability. -C.1.11 Section 4.1.12 +C.1.11 Section 4.1.12 (Controls) - Specified how control values defined in terms of ASN.1 are to be encoded. - - Noted that the criticality field is only applied to request - messages (except unbindRequest), and must be ignored when present - on response messages and unbindRequest. - - Added language regarding combinations of controls and the ordering - of controls on a message. - - -Sermersheim Internet-Draft - Expires Apr 2005 Page 55 +Sermersheim Internet-Draft - Expires Aug 2005 Page 57 + Lightweight Directory Access Protocol Version 3 + - Noted that the criticality field is only applied to request + messages (except UnbindRequest), and must be ignored when present + on response messages and UnbindRequest. + - Added language regarding combinations of controls and the ordering + of controls on a message. - Specified that when the semantics of the combination of controls is undefined or unknown, it results in a protocolError. - Changed "The server MUST be prepared" to "Implementations MUST be @@ -3210,13 +3372,13 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 55 controls). -C.1.12 Section 4.2 +C.1.12 Section 4.2 (Bind Operation) - Mandated that servers return protocolError when the version is not supported. - - Clarified behavior when the simple authentication is used, the + - Disambiguated behavior when the simple authentication is used, the name is empty and the password is non-empty. - - Required servers to not dereference aliases for bind. This was + - Required servers to not dereference aliases for Bind. This was added for consistency with other operations and to help ensure data consistency. - Required that textual passwords be transferred as UTF-8 encoded @@ -3225,55 +3387,54 @@ C.1.12 Section 4.2 different clients. -C.1.13 Section 4.2.1 +C.1.13 Section 4.2.1 (Sequencing of the Bind Request) - This section was largely reorganized for readability and language was added to clarify the authentication state of failed and - abandoned bind operations. + abandoned Bind operations. - Removed: "If a SASL transfer encryption or integrity mechanism has been negotiated, that mechanism does not support the changing of credentials from one identity to another, then the client MUST instead establish a new connection." - Each SASL negotiation is, generally, independent of other SASL - negotiations. If there were dependencies between multiple - negotiations of a particular mechanism, the mechanism technical - specification should detail how applications are to deal with - them. LDAP should not require any special handling. And if an LDAP - client had used such a mechanism, it would have the option of - using another mechanism. + If there are dependencies between multiple negotiations of a + particular SASL mechanism, the technical specification for that + SASL mechanism details how applications are to deal with them. + LDAP should not require any special handling. - Dropped MUST imperative in paragraph 3 to align with [Keywords]. - - Mandated that clients not send non-bind operations while a bind is + - Mandated that clients not send non-Bind operations while a Bind is in progress, and suggested that servers not process them if they are received. This is needed to ensure proper sequencing of the - bind in relationship to other operations. + Bind in relationship to other operations. -C.1.14 Section 4.2.3 +C.1.14 Section 4.2.3 (Bind Response) - Moved most error-related text to Appendix A, and added text - regarding certain errors used in conjunction with the bind + regarding certain errors used in conjunction with the Bind operation. - - Prohibited the server from specifying serverSaslCreds when not - appropriate. - + -Sermersheim Internet-Draft - Expires Apr 2005 Page 56 +Sermersheim Internet-Draft - Expires Aug 2005 Page 58 + Lightweight Directory Access Protocol Version 3 + - Prohibited the server from specifying serverSaslCreds when not + appropriate. -C.1.15 Section 4.3 + +C.1.15 Section 4.3 (Unbind Operation) - - Required both peers to cease transmission and close the LDAP - exchange for the unbind operation. + - Specified that both peers are to cease transmission and terminate + the LDAP session for the Unbind operation. -C.1.16 Section 4.4 +C.1.16 Section 4.4 (Unsolicited Notification) - Added instructions for future specifications of Unsolicited Notifications. -C.1.17 Section 4.5.1 +C.1.17 Section 4.5.1 (Search Request) - SearchRequest attributes is now defined as an AttributeSelection type rather than AttributeDescriptionList, and an ABNF is @@ -3289,12 +3450,14 @@ C.1.17 Section 4.5.1 are now AssertionValue rather than LDAPString. Also, added imperatives stating that 'initial' (if present) must be listed first, and 'final' (if present) must be listed last. - - Clarified the semantics of the derefAliases choices. + - Disambiguated the semantics of the derefAliases choices. There was + question as to whether derefInSearching applied to the base object + in a wholeSubtree Search. - Added instructions for equalityMatch, substrings, greaterOrEqual, lessOrEqual, and approxMatch. -C.1.18 Section 4.5.2 +C.1.18 Section 4.5.2 (Search Result) - Recommended that servers not use attribute short names when it knows they are ambiguous or may cause interoperability problems. @@ -3302,91 +3465,96 @@ C.1.18 Section 4.5.2 implementation. -C.1.19 Section 4.5.3 +C.1.19 Section 4.5.3 (Continuation References in the Search Result) - Made changes similar to those made to Section 4.1.11. -C.1.20 Section 4.5.3.1 - - - Fixed examples to adhere to changes made to Section 4.5.3. - - -C.1.21 Section 4.6 +C.1.20 Section 4.5.3.1 (Example) -Sermersheim Internet-Draft - Expires Apr 2005 Page 57 +Sermersheim Internet-Draft - Expires Aug 2005 Page 59 + Lightweight Directory Access Protocol Version 3 - - Removed restriction that required an EQUALITY matching rule in - order to perform value delete modifications. It is sufficiently - documented that in absence of an equality matching rule, octet - equality is used. + - Fixed examples to adhere to changes made to Section 4.5.3. + + +C.1.21 Section 4.6 (Modify Operation) + - Replaced AttributeTypeAndValues with Attribute as they are equivalent. - - Clarified what type of modification changes might temporarily - violate schema. + - Specified the types of modification changes which might + temporarily violate schema. Some readers were under the impression + that any temporary schema violation was allowed. -C.1.22 Section 4.7 +C.1.22 Section 4.7 (Add Operation) - Aligned Add operation with X.511 in that the attributes of the RDN are used in conjunction with the listed attributes to create the entry. Previously, Add required that the distinguished values be present in the listed attributes. + - Removed requirement that the objectClass attribute MUST be + specified as some DSE types do not require this attribute. + Instead, generic wording was added, requiring the added entry to + adhere to the data model. + - Removed recommendation regarding placement of objects. This is + covered in the data model document. -C.1.23 Section 4.9 +C.1.23 Section 4.9 (Modify DN Operation) - - Required servers to not dereference aliases for modify DN. This + - Required servers to not dereference aliases for Modify DN. This was added for consistency with other operations and to help ensure data consistency. - - Allow modify DN to fail when moving between naming contexts. - - Specified what happens when the attributes of the newrdn are no + - Allow Modify DN to fail when moving between naming contexts. + - Specified what happens when the attributes of the newrdn are not present on the entry. -C.1.24 Section 4.10 +C.1.24 Section 4.10 (Compare Operation) - - Clarified that compareFalse means that the compare took place and + - Specified that compareFalse means that the Compare took place and the result is false. There was confusion which lead people to believe that an Undefined match resulted in compareFalse. - - Required servers to not dereference aliases for compare. This was + - Required servers to not dereference aliases for Compare. This was added for consistency with other operations and to help ensure data consistency. -C.1.25 Section 4.11 +C.1.25 Section 4.11 (Abandon Operation) - - Explained that since abandon returns no response, clients should + - Explained that since Abandon returns no response, clients should not use it if they need to know the outcome. - Specified that Abandon and Unbind cannot be abandoned. -C.1.26 Section 4.12 +C.1.26 Section 4.12 (Extended Operation) + +Sermersheim Internet-Draft - Expires Aug 2005 Page 60 + + Lightweight Directory Access Protocol Version 3 + - - Specified how values of extended operations defined in terms of + - Specified how values of Extended operations defined in terms of ASN.1 are to be encoded. - - Added instructions on what extended operation specifications + - Added instructions on what Extended operation specifications consist of. - - Added a recommendation that servers advertise supported extended + - Added a recommendation that servers advertise supported Extended operations. - -Sermersheim Internet-Draft - Expires Apr 2005 Page 58 - Lightweight Directory Access Protocol Version 3 - -C.1.27 Section 5.2 +C.1.27 Section 5.2 (Transfer Protocols) - Moved referral-specific instructions into referral-related sections. -C.1.28 Section 7 +C.1.28 Section 7 (Security Considerations) - Reworded notes regarding SASL not protecting certain aspects of - the LDAP bind PDU. + the LDAP Bind PDUs. - Noted that Servers are encouraged to prevent directory modifications by clients that have authenticated anonymously [AuthMeth]. @@ -3400,7 +3568,7 @@ C.1.28 Section 7 - Added a note regarding malformed and long encodings. -C.1.29 Appendix A +C.1.29 Appendix A (Complete ASN.1 Definition) - Added "EXTENSIBILITY IMPLIED" to ASN.1 definition. - Removed AttributeType. It is not used. @@ -3413,31 +3581,37 @@ C.2 Changes made to RFC 2830: to other sections. -C.2.1 Section 2.3 +C.2.1 Section 2.3 (Response other than "success") - Removed wording indicating that referrals can be returned from - StartTLS + StartTLS. - Removed requirement that only a narrow set of result codes can be returned. Some result codes are required in certain scenarios, but any other may be returned if appropriate. -C.2.1 Section 4.13.3.1 + +Sermersheim Internet-Draft - Expires Aug 2005 Page 61 + + Lightweight Directory Access Protocol Version 3 + +C.2.1 Section 4 (Closing a TLS Connection) - Reworded most of this section and added the requirement that after the TLS connection has been closed, the server MUST NOT send responses to any request message received before the TLS closure. + - Removed instructions on abrupt closure as this is covered in other + areas of the document (specifically, Section 5.3) C.3 Changes made to RFC 3771: - -Sermersheim Internet-Draft - Expires Apr 2005 Page 59 - Lightweight Directory Access Protocol Version 3 - - - In general, all technical language was transferred in whole. - Supporting and background language seen as redundant due to its - presence in this document was omitted. + - Rewrote to fit into this document. In general, semantics were + preserved. Supporting and background language seen as redundant + due to its presence in this document was omitted. + - Specified that Intermediate responses to a request may be of + different types, and one of the response types may be specified to + have no response value. @@ -3460,20 +3634,6 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 59 - - - - - - - - - - - - - - @@ -3490,7 +3650,8 @@ Sermersheim Internet-Draft - Expires Apr 2005 Page 59 -Sermersheim Internet-Draft - Expires Apr 2005 Page 60 +Sermersheim Internet-Draft - Expires Aug 2005 Page 62 + Lightweight Directory Access Protocol Version 3 @@ -3547,6 +3708,6 @@ Acknowledgement - -Sermersheim Internet-Draft - Expires Apr 2005 Page 61 \ No newline at end of file +Sermersheim Internet-Draft - Expires Aug 2005 Page 63 + -- 2.39.5