--- 1/draft-ietf-ldapbis-protocol-19.txt 2006-02-05 00:12:16.000000000 +0100 +++ 2/draft-ietf-ldapbis-protocol-20.txt 2006-02-05 00:12:16.000000000 +0100 @@ -1,14 +1,14 @@ Internet-Draft Editor: J. Sermersheim Intended Category: Standard Track Novell, Inc -Document: draft-ietf-ldapbis-protocol-19.txt Dec 2003 +Document: draft-ietf-ldapbis-protocol-20.txt Jan 2004 Obsoletes: RFC 2251, 2830 LDAP: The Protocol Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering @@ -43,77 +43,77 @@ 1. Introduction....................................................2 1.1. Relationship to Obsolete Specifications.......................3 2. Conventions.....................................................3 3. Protocol Model..................................................3 4. Elements of Protocol............................................4 4.1. Common Elements...............................................4 4.1.1. Message Envelope............................................4 4.1.2. String Types................................................6 -Sermersheim Internet-Draft - Expires Jun 2004 Page 1 +Sermersheim Internet-Draft - Expires Jul 2004 Page 1 Lightweight Directory Access Protocol Version 3 4.1.3. Distinguished Name and Relative Distinguished Name..........6 4.1.4. Attribute Descriptions......................................7 4.1.5. Attribute Value.............................................7 4.1.6. Attribute Value Assertion...................................7 4.1.7. Attribute and PartialAttribute..............................8 4.1.8. Matching Rule Identifier....................................8 4.1.9. Result Message..............................................8 4.1.10. Referral..................................................10 4.1.11. Controls..................................................11 4.2. Bind Operation...............................................12 4.3. Unbind Operation.............................................15 - 4.4. Unsolicited Notification.....................................16 + 4.4. Unsolicited Notification.....................................15 4.5. Search Operation.............................................17 4.6. Modify Operation.............................................25 - 4.7. Add Operation................................................26 - 4.8. Delete Operation.............................................27 + 4.7. Add Operation................................................27 + 4.8. Delete Operation.............................................28 4.9. Modify DN Operation..........................................28 4.10. Compare Operation...........................................29 4.11. Abandon Operation...........................................30 - 4.12. Extended Operation..........................................30 - 4.13. StartTLS Operation..........................................31 - 5. Protocol Element Encodings and Transfer........................33 + 4.12. Extended Operation..........................................31 + 4.13. StartTLS Operation..........................................32 + 5. Protocol Element Encodings and Transfer........................34 5.1. Protocol Encoding............................................34 - 5.2. Transfer Protocols...........................................34 - 6. Security Considerations........................................34 + 5.2. Transfer Protocols...........................................35 + 6. Security Considerations........................................35 7. Acknowledgements...............................................36 8. Normative References...........................................36 - 9. Informative References.........................................37 - 10. IANA Considerations...........................................37 + 9. Informative References.........................................38 + 10. IANA Considerations...........................................38 11. Editor's Address..............................................38 Appendix A - LDAP Result Codes....................................39 A.1 Non-Error Result Codes........................................39 A.2 Result Codes..................................................39 Appendix B - Complete ASN.1 Definition............................43 - Appendix C - Changes..............................................48 - C.1 Changes made to made to RFC 2251:.............................48 - C.2 Changes made to made to RFC 2830:.............................53 + Appendix C - Changes..............................................49 + C.1 Changes made to made to RFC 2251:.............................49 + C.2 Changes made to made to RFC 2830:.............................54 1. Introduction The Directory is "a collection of open systems cooperating to provide directory services" [X.500]. A directory user, which may be a human or other entity, accesses the Directory through a client (or Directory User Agent (DUA)). The client, on behalf of the directory user, interacts with one or more servers (or Directory System Agents (DSA)). Clients interact with servers using a directory access protocol. This document details the protocol elements of the Lightweight Directory Access Protocol (LDAP), along with their semantics. Following the description of protocol elements, it describes the way in which the protocol elements are encoded and transferred. -Sermersheim Internet-Draft - Expires Jun 2004 Page 2 +Sermersheim Internet-Draft - Expires Jul 2004 Page 2 Lightweight Directory Access Protocol Version 3 1.1. Relationship to Obsolete Specifications This document is an integral part of the LDAP Technical Specification [Roadmap] which obsoletes the previously defined LDAP technical specification, RFC 3377, in its entirety. This document obsoletes all of RFC 2251 except the following: Sections 3.2, 3.4, 4.1.3 (last paragraph), 4.1.4, 4.1.5, 4.1.5.1, @@ -131,100 +131,102 @@ 2. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", and "MAY" in this document are to be interpreted as described in [Keyword]. The terms "connection" and "LDAP connection" both refer to the underlying transport protocol connection between two protocol peers. - The term "TLS connection" refers to a TLS-protected LDAP connection. + The term "TLS connection" refers to a [TLS]-protected LDAP + connection. The terms "association" and "LDAP association" both refer to the association of the LDAP connection and its current authentication and authorization state. 3. Protocol Model The general model adopted by this protocol is one of clients performing protocol operations against servers. In this model, a client transmits a protocol request describing the operation to be performed to a server. The server is then responsible for performing - the necessary operation(s) in the Directory. Upon completion of the - operation(s), the server returns a response containing an appropriate - result code to the requesting client. + the necessary operation(s) in the Directory. Upon completion of an + operation, the server typically returns a response containing + appropriate data to the requesting client. Although servers are required to return responses whenever such responses are defined in the protocol, there is no requirement for synchronous behavior on the part of either clients or servers. - Requests and responses for multiple operations may be exchanged - between a client and server in any order, provided the client - eventually receives a response for every request that requires one. + Requests and responses for multiple operations generally may be + exchanged between a client and server in any order, provided the -Sermersheim Internet-Draft - Expires Jun 2004 Page 3 +Sermersheim Internet-Draft - Expires Jul 2004 Page 3 Lightweight Directory Access Protocol Version 3 + client eventually receives a response for every request that requires + one. + The core protocol operations defined in this document can be mapped - to a subset of the X.500 (1993) Directory Abstract Service. However - there is not a one-to-one mapping between LDAP protocol operations - and X.500 Directory Access Protocol (DAP) operations. Server + to a subset of the X.500 (1993) Directory Abstract Service [X.511]. + However there is not a one-to-one mapping between LDAP operations and + X.500 Directory Access Protocol (DAP) operations. Server implementations acting as a gateway to X.500 directories may need to make multiple DAP requests to service a single LDAP request. 4. Elements of Protocol - The LDAP protocol is described using Abstract Syntax Notation One + The protocol is described using Abstract Syntax Notation One ([ASN.1]), and is transferred using a subset of ASN.1 Basic Encoding Rules ([BER]). Section 5.1 specifies how the protocol elements are encoded and transferred. - In order to support future Standards Track extensions to this - protocol, extensibility is implied where it is allowed (per ASN.1). - In addition, ellipses (...) have been supplied in ASN.1 types that - are explicitly extensible as discussed in [LDAPIANA]. Because of the - implied extensibility, clients and servers MUST (unless otherwise - specified) ignore trailing SEQUENCE components whose tags they do not - recognize. + In order to support future extensions to this protocol, extensibility + is implied where it is allowed (per ASN.1). In addition, ellipses + (...) have been supplied in ASN.1 types that are explicitly + extensible as discussed in [LDAPIANA]. Because of the implied + extensibility, clients and servers MUST (unless otherwise specified) + ignore trailing SEQUENCE components whose tags they do not recognize. - Changes to the LDAP 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 client is using version 3 or later. + 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 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- + reading the 'supportedLDAPVersion' attribute from the root DSE (DSA- Specific Entry) [Models]. 4.1. Common Elements This section describes the LDAPMessage envelope Protocol Data Unit (PDU) format, as well as data type definitions, which are used in the protocol operations. 4.1.1. Message Envelope For the purposes of protocol exchanges, all protocol operations are encapsulated in a common envelope, the LDAPMessage, which is defined as follows: LDAPMessage ::= SEQUENCE { messageID MessageID, protocolOp CHOICE { bindRequest BindRequest, bindResponse BindResponse, - unbindRequest UnbindRequest, -Sermersheim Internet-Draft - Expires Jun 2004 Page 4 +Sermersheim Internet-Draft - Expires Jul 2004 Page 4 Lightweight Directory Access Protocol Version 3 + unbindRequest UnbindRequest, searchRequest SearchRequest, searchResEntry SearchResultEntry, searchResDone SearchResultDone, searchResRef SearchResultReference, modifyRequest ModifyRequest, modifyResponse ModifyResponse, addRequest AddRequest, addResponse AddResponse, delRequest DelRequest, delResponse DelResponse, @@ -235,81 +237,81 @@ abandonRequest AbandonRequest, extendedReq ExtendedRequest, extendedResp ExtendedResponse, ... }, controls [0] Controls OPTIONAL } MessageID ::= INTEGER (0 .. maxInt) maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- + The ASN.1 type Controls is defined in Section 4.1.11. + The function of the LDAPMessage is to provide an envelope containing common fields required in all protocol exchanges. At this time the only common fields are the message ID and the controls. If the server receives a PDU from the client in which the LDAPMessage SEQUENCE tag cannot be recognized, the messageID cannot be parsed, the tag of the protocolOp is not recognized as a request, or the 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. 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. - The ASN.1 type Controls is defined in Section 4.1.11. - 4.1.1.1. Message ID All LDAPMessage envelopes encapsulating responses contain the messageID value of the corresponding request LDAPMessage. The message ID of a request MUST have a non-zero value different from the values of any other requests outstanding in the LDAP association - of which this message is a part. The zero value is reserved for the - unsolicited notification message. -Sermersheim Internet-Draft - Expires Jun 2004 Page 5 +Sermersheim Internet-Draft - Expires Jul 2004 Page 5 Lightweight Directory Access Protocol Version 3 + of which this message is a part. 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 on the same LDAP association unless it can be - determined that the server is no longer servicing the earlier - request. Otherwise the behavior is undefined. For operations that do - not return responses (unbind, abandon, and abandoned operations), the - client SHOULD assume the operation is in progress until a subsequent - bind request completes. + determined that the server is no longer servicing the earlier request + (e.g. 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. 4.1.2. String Types The LDAPString is a notational convenience to indicate that, although strings of LDAPString type encode as ASN.1 OCTET STRING types, the [ISO10646] character set (a superset of [Unicode]) is used, encoded following the [UTF-8] algorithm. Note that Unicode characters U+0000 through U+007F are the same as ASCII 0 through 127, respectively, and have the same single octet UTF-8 encoding. Other Unicode characters have a multiple octet UTF-8 encoding. LDAPString ::= OCTET STRING -- UTF-8 encoded, -- [ISO10646] characters The LDAPOID is a notational convenience to indicate that the permitted value of this string is a (UTF-8 encoded) dotted-decimal representation of an OBJECT IDENTIFIER. Although an LDAPOID is encoded as an OCTET STRING, values are limited to the definition of - given in Section 1.3 of [Models]. + given in Section 1.4 of [Models]. LDAPOID ::= OCTET STRING -- Constrained to [Models] For example, 1.3.6.1.4.1.1466.1.2.3 4.1.3. Distinguished Name and Relative Distinguished Name An LDAPDN is defined to be the representation of a Distinguished Name @@ -318,21 +320,21 @@ LDAPDN ::= LDAPString -- Constrained to [LDAPDN] A RelativeLDAPDN is defined to be the representation of a Relative Distinguished Name (RDN) after encoding according to the specification in [LDAPDN]. RelativeLDAPDN ::= LDAPString -- Constrained to [LDAPDN] -Sermersheim Internet-Draft - Expires Jun 2004 Page 6 +Sermersheim Internet-Draft - Expires Jul 2004 Page 6 Lightweight Directory Access Protocol Version 3 4.1.4. Attribute Descriptions The definition and encoding rules for attribute descriptions are defined in Section 2.5 of [Models]. Briefly, an attribute description is an attribute type and zero or more options. AttributeDescription ::= LDAPString -- Constrained to @@ -343,109 +345,112 @@ A field of type AttributeValue is an OCTET STRING containing an encoded attribute value. The attribute value is encoded according to the LDAP-specific encoding definition of its corresponding syntax. The LDAP-specific encoding definitions for different syntaxes and attribute types may be found in other documents and in particular [Syntaxes]. AttributeValue ::= OCTET STRING Note that there is no defined limit on the size of this encoding; - thus protocol values may include multi-megabyte attributes (e.g. - photographs). + thus protocol values may include multi-megabyte attribute values + (e.g. photographs). - Attributes may be defined which have arbitrary and non-printable - syntax. Implementations MUST NOT display nor attempt to decode a - value if its syntax is not known. The implementation may attempt to - discover the subschema of the source entry, and retrieve the - descriptions of attributeTypes from it [Models]. + Attribute values may be defined which have arbitrary and non- + printable syntax. Implementations MUST NOT display nor attempt to + decode an attribute value if its syntax is not known. The + implementation may attempt to discover the subschema of the source + entry, and retrieve the descriptions of 'attributeTypes' from it + [Models]. - Clients MUST NOT send attribute values in a request that are not - valid according to the syntax defined for the attributes. + Clients MUST only send attribute values in a request that are valid + according to the syntax defined for the attributes. 4.1.6. Attribute Value Assertion - The AttributeValueAssertion type definition is similar to the one in - the X.500 Directory standards. It contains an attribute description - and a matching rule assertion value suitable for that type. + 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 + 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. AttributeValueAssertion ::= SEQUENCE { attributeDesc AttributeDescription, assertionValue AssertionValue } AssertionValue ::= OCTET STRING +Sermersheim Internet-Draft - Expires Jul 2004 Page 7 + 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 operation. Often this is the same syntax used for values of the attribute type, but in some cases the assertion syntax differs from - -Sermersheim Internet-Draft - Expires Jun 2004 Page 7 - Lightweight Directory Access Protocol Version 3 - the value syntax. See objectIdentiferFirstComponentMatch in [Syntaxes] for an example. 4.1.7. Attribute and PartialAttribute Attributes and partial attributes consist of an attribute description - and values of that attribute description. A PartialAttribute allows - zero values, while Attribute requires at least one value. + and attribute values. A PartialAttribute allows zero values, while + Attribute requires at least one value. PartialAttribute ::= SEQUENCE { type AttributeDescription, vals SET OF value AttributeValue } Attribute ::= PartialAttribute(WITH COMPONENTS { ..., vals (SIZE(1..MAX))}) - Each attribute value is distinct in the set (no duplicates). The set - of attribute values is unordered. Implementations MUST NOT rely upon - the ordering being repeatable. + No two attribute values are 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. 4.1.8. Matching Rule Identifier - Matching rules are defined in 4.1.3 of [Models]. A matching rule is - identified in the LDAP protocol by the printable representation of + Matching rules are defined in Section 4.1.3 of [Models]. A matching + rule is identified in the protocol by the printable representation of either its , or one of its short name descriptors - [Models], e.g. "caseIgnoreIA5Match" or "1.3.6.1.4.1.453.33.33". + [Models], e.g. 'caseIgnoreMatch' or '2.5.13.2'. MatchingRuleId ::= LDAPString 4.1.9. Result Message 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. LDAPResult ::= SEQUENCE { resultCode ENUMERATED { success (0), operationsError (1), protocolError (2), timeLimitExceeded (3), sizeLimitExceeded (4), compareFalse (5), compareTrue (6), + +Sermersheim Internet-Draft - Expires Jul 2004 Page 8 + Lightweight Directory Access Protocol Version 3 + authMethodNotSupported (7), strongAuthRequired (8), -- 9 reserved -- referral (10), adminLimitExceeded (11), - -Sermersheim Internet-Draft - Expires Jun 2004 Page 8 - Lightweight Directory Access Protocol Version 3 - unavailableCriticalExtension (12), confidentialityRequired (13), saslBindInProgress (14), noSuchAttribute (16), undefinedAttributeType (17), inappropriateMatching (18), constraintViolation (19), attributeOrValueExists (20), invalidAttributeSyntax (21), -- 22-31 unused -- @@ -467,42 +472,42 @@ objectClassViolation (65), notAllowedOnNonLeaf (66), notAllowedOnRDN (67), entryAlreadyExists (68), objectClassModsProhibited (69), -- 70 reserved for CLDAP -- affectsMultipleDSAs (71), -- 72-79 unused -- other (80), ... }, - -- 81-90 reserved for APIs -- matchedDN LDAPDN, diagnosticMessage LDAPString, referral [3] Referral OPTIONAL } - The resultCode enumeration is extensible as defined in Section 3.5 of - [LDAPIANA]. The meanings of the result codes are given in Appendix A. - If a server detects multiple errors for an operation, only one result - code is returned. The server should return the result code that best - indicates the nature of the error encountered. + The resultCode enumeration is extensible as defined in Section 3.6 of + [LDAPIANA]. The meanings of the listed result codes are given in + Appendix A. If a server detects multiple errors for an operation, + only one result code is returned. The server should return the result + code that best indicates the nature of the error encountered. 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 avoided) diagnostic message. As this diagnostic message is not + +Sermersheim Internet-Draft - Expires Jul 2004 Page 9 + Lightweight Directory Access Protocol Version 3 + 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. -Sermersheim Internet-Draft - Expires Jun 2004 Page 9 - Lightweight Directory Access Protocol Version 3 - For certain result codes (typically, but not restricted to noSuchObject, aliasProblem, invalidDNSyntax and aliasDereferencingProblem), the matchedDN field is set to the name of the lowest entry (object or alias) in the Directory that was matched. 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. 4.1.10. Referral @@ -512,229 +517,229 @@ 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. 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 the search scope spans multiple naming contexts, and several - different servers would need to be contacted to complete the + when other servers would need to be contacted to complete the operation. Referral ::= SEQUENCE SIZE (1..MAX) OF uri URI 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 services. If multiple URIs are - present, the client assumes that any URI may be used to progress the - operation. + 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. Clients 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 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 between the root and a leaf entry. A URI for a server implementing LDAP and accessible via [TCP]/[IP] (v4 or v6) is written as an LDAP URL according to [LDAPURL]. When an LDAP URL is used, the following instructions are followed: - - If an alias was dereferenced, the part of the URL MUST be - present, with the new target object name. Note that UTF-8 - characters appearing in a DN or search filter may not be legal -Sermersheim Internet-Draft - Expires Jun 2004 Page 10 +Sermersheim Internet-Draft - Expires Jul 2004 Page 10 Lightweight Directory Access Protocol Version 3 - for URLs (e.g. spaces) and MUST be escaped using the % method in - [URI]. + - 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]. - 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 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. - Some servers (e.g. participating in distributed indexing) may 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. - - For search, it is RECOMMENDED that the part be present - to avoid ambiguity. + - For search, it is RECOMMENDED that the part be present to + avoid ambiguity. - 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 from the request which generated the referral. Other kinds of URIs may be returned. The syntax and semantics of such - URIs is left to future specifications. Clients ignore URIs that they - do not support. + URIs is left to future specifications. Clients may ignore URIs that + they do not support. 4.1.11. Controls A control is a way to specify extension information for an LDAP message. A control only alters the semantics of the message it is attached to. Controls ::= SEQUENCE OF control Control Control ::= SEQUENCE { controlType LDAPOID, criticality BOOLEAN DEFAULT FALSE, controlValue OCTET STRING OPTIONAL } The controlType field is the UTF-8 encoded dotted-decimal representation of an OBJECT IDENTIFIER which uniquely identifies the control, or the request control and its paired response control. This prevents conflicts between control names. The criticality field is either TRUE or FALSE and only applies to - request messages that have a corresponding response message. For all - other messages (such as abandonRequest, unbindRequest and all - response messages), the criticality field SHOULD be FALSE. + request messages (except unbindRequest). For response messages and + unbindRequest, the criticality field SHOULD be FALSE, and is ignored + by the receiving protocol peer. + +Sermersheim Internet-Draft - Expires Jul 2004 Page 11 + Lightweight Directory Access Protocol Version 3 If the server recognizes the control type and it is appropriate for the operation, the server will make use of the control when performing the operation. -Sermersheim Internet-Draft - Expires Jun 2004 Page 11 - Lightweight Directory Access Protocol Version 3 - 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, MUST set the resultCode to unavailableCriticalExtension. + response, MUST return unavailableCriticalExtension in the resultCode. If the control is unrecognized or inappropriate but the criticality field is FALSE, the server MUST ignore the control. The controlValue contains any information associated with the control. Its format is defined by the specification of the control. Implementations MUST be prepared to handle arbitrary 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. controlValues that are defined in terms of ASN.1 and BER encoded according to Section 5.1, also follow the extensibility rules in Section 4. Servers list the controlType of all request controls they recognize - in the supportedControl attribute [Models] in the root DSE. + in the supportedControl attribute in the root DSE (Section 5.1 of + [Models]). 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 specification most recently published. In the absence of combination semantics, the behavior of the operation is undefined. Additionally, unless order-dependent semantics are given in a specification, the order of a combination of controls in the SEQUENCE is ignored. This document does not specify any controls. Controls may be specified in other documents. The specification of a control consists of: - the OBJECT IDENTIFIER assigned to the control, - - whether the control is always non critical, always critical, or - optionally critical, + - whether the criticality field should be always set to TRUE, always + set to FALSE, or sender's choice, and server behavior when + constraints of this nature are violated, - whether there is information associated with the control, and if so, the format of the controlValue contents, - the semantics of the control, and - optionally, semantics regarding the combination of the control with other controls. 4.2. Bind Operation +Sermersheim Internet-Draft - Expires Jul 2004 Page 12 + Lightweight Directory Access Protocol Version 3 + 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. Authentication and security-related semantics of this operation are given in [AuthMeth]. -Sermersheim Internet-Draft - Expires Jun 2004 Page 12 - Lightweight Directory Access Protocol Version 3 - The Bind Request is defined as follows: BindRequest ::= [APPLICATION 0] SEQUENCE { version INTEGER (1 .. 127), name LDAPDN, authentication AuthenticationChoice } AuthenticationChoice ::= CHOICE { simple [0] OCTET STRING, -- 1 and 2 reserved sasl [3] SaslCredentials, ... } SaslCredentials ::= SEQUENCE { mechanism LDAPString, credentials OCTET STRING OPTIONAL } - Parameters of the Bind Request are: + Fields of the Bind Request are: - version: A version number indicating the version of the protocol - to be used in this protocol association. This document describes - version 3 of the LDAP protocol. Note that there is no version - negotiation. The client sets this parameter to the version it - desires. If the server does not support the specified version, it - MUST respond with protocolError in the resultCode field of the - BindResponse. + to be used in this LDAP association. 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 + protocolError in the resultCode field of the BindResponse. - name: The name of the Directory object that the client wishes to bind as. This field may take on a null value (a zero length - string) for the purposes of anonymous binds ([AuthMeth] Section 7) - or when using Simple Authentication and Security Layer [SASL] - authentication ([AuthMeth] Section 4.3). Server behavior is + string) for the purposes of anonymous binds ([AuthMeth] Section + 5.1) or when using Simple Authentication and Security Layer [SASL] + authentication ([AuthMeth] Section 3.3.2). Server behavior is undefined when the name is a null value, simple authentication is - used, and a password is specified. The server SHALL NOT perform - alias dereferencing in determining the object to bind as. + used, and a non-null password is specified. Where the server + attempts to locate the named object, it SHALL NOT perform alias + dereferencing. + + - 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. - - authentication: information used to authenticate the name, if any, - provided in the Bind Request. This type is extensible as defined - in Section 3.6 of [LDAPIANA]. Servers that do not support a choice - supplied by a client will return authMethodNotSupported in the - resultCode field of the BindResponse. - The simple form of an AuthenticationChoice specifies a simple - password to be used for authentication. Textual passwords (consisting of a character sequence with a known - character set and encoding) SHALL be transferred as [UTF-8] - encoded [Unicode]. The determination of whether a password is - textual is a local client matter. - Prior to transfer, clients SHOULD prepare text passwords by - applying the [SASLprep] profile of the [Stringprep] algorithm. - Passwords consisting of other data (such as random octets) MUST - NOT be altered. + character set and encoding) transferred to the server using the + simple AuthenticationChoice SHALL be transferred as [UTF-8] + encoded [Unicode]. Prior to transfer, clients SHOULD prepare text + passwords by applying the [SASLprep] profile of the [Stringprep] -Sermersheim Internet-Draft - Expires Jun 2004 Page 13 +Sermersheim Internet-Draft - Expires Jul 2004 Page 13 Lightweight Directory Access Protocol Version 3 + algorithm. Passwords consisting of other data (such as random + octets) MUST NOT be altered. The determination of whether a + password is textual is a local client matter. + Authorization is the use of this authentication information when performing operations. Authorization MAY be affected by factors outside of the LDAP Bind Request, such as those provided by lower layer security services. 4.2.1. Processing of the Bind Request - Before processing a BindResponse, all outstanding operations MUST + Before processing a BindRequest, all outstanding operations MUST either complete or be abandoned. The server may either wait for the outstanding 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 BindResponse to indicate the status of authentication. 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 this also fails or the client chooses not to bind on the existing connection, it may close the connection, reopen it and begin again by @@ -744,169 +749,158 @@ Clients may send multiple Bind Requests on a connection 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. This is indicated by the server sending a BindResponse with the resultCode set to saslBindInProgress. This indicates that the server requires the client to send a new bind request, with the same sasl mechanism, to - continue the authentication process. If at any stage the client - wishes to abort the bind process it MAY unbind and then drop the - underlying connection. Clients MUST NOT invoke operations between two - Bind Requests made as part of a multi-stage bind. + continue the authentication process. 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 abort a negotiation if it wishes to try again with the same SASL mechanism. - A failed Bind Operation has the effect of leaving the connection in - an anonymous state. An abandoned Bind operation also has the effect - of leaving the connection in an anonymous state when (and if) the - server processes the abandonment of the bind. Client implementers - should note that the client has no way of being sure when (or if) an - abandon request succeeds, therefore, to arrive at a known - authentication state after abandoning a bind operation, clients may - -Sermersheim Internet-Draft - Expires Jun 2004 Page 14 - Lightweight Directory Access Protocol Version 3 - - either unbind (which results in the underlying connection being - closed) or by issuing a bind request and then examining the - BindResponse returned by the server. + A failed Bind Operation has the effect of placing the connection in + an anonymous state. 4.2.2. Bind Response +Sermersheim Internet-Draft - Expires Jul 2004 Page 14 + Lightweight Directory Access Protocol Version 3 + The Bind Response is defined as follows. BindResponse ::= [APPLICATION 1] SEQUENCE { COMPONENTS OF LDAPResult, serverSaslCreds [7] OCTET STRING OPTIONAL } 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 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. - If the client receives a BindResponse response where the resultCode - field is protocolError, it MUST close the connection as the server - will be unwilling to accept further operations. (This is for - compatibility with earlier versions of LDAP, in which the bind was - always the first operation, and there was no negotiation.) + If the client receives a BindResponse where the resultCode field is + 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 establishing a + new 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 drop the underlying connection. - The serverSaslCreds are 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 does - not require the server to return information to the client, then this - field SHALL NOT be included in the BindResponse. + 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 + does not require the server to return information to the client, then + this field SHALL NOT be included in the BindResponse. 4.3. Unbind Operation The function of the Unbind Operation is to terminate an LDAP association and 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 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 association terminated, MUST cease transmission of messages to the - other peer, and MUST close the connection. Any outstanding operations - on the server are, when possible, abandoned, and when not possible, - completed without transmission of the response. - -Sermersheim Internet-Draft - Expires Jun 2004 Page 15 - Lightweight Directory Access Protocol Version 3 + other peer, and MUST close the connection. Outstanding operations are + handled as specified in Section 5.2. 4.4. Unsolicited Notification +Sermersheim Internet-Draft - Expires Jul 2004 Page 15 + Lightweight Directory Access Protocol Version 3 + 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 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. The unsolicited notification is structured as an LDAPMessage in which - the messageID is zero and protocolOp is of the extendedResp form. The - responseName field of the ExtendedResponse always contains an LDAPOID - which is unique for this notification. + 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. One unsolicited notification (Notice of Disconnection) is defined in this document. The specification of an unsolicited notification consists of: - the OBJECT IDENTIFIER assigned to the notification (to be specified in the responseName, - the format of the contents (if any) of the responseValue, - the circumstances which will cause the notification to be returned, and - the semantics of the operation. 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. Note that this notification is NOT a response to an unbind - requested by the client: the server MUST follow the procedures of - Section 4.3. This notification is intended to assist clients in + condition. This notification is intended to assist clients in distinguishing between an error condition and a transient network - failure. As with a connection close due to network failure, the - client MUST NOT assume that any outstanding requests which modified - the Directory have succeeded or failed. + failure. Note that this notification is not a response to an unbind + requested by the client. Outstanding operations are handled as + specified in Section 5.2. The responseName is 1.3.6.1.4.1.1466.20036, the response field is absent, and the resultCode is used to indicate the reason for the disconnection. The following result codes have these meanings when used in this notification: - protocolError: The server has received data from the client in which the LDAPMessage structure could not be parsed. - strongAuthRequired: The server has detected that an established security association between the client and server has - -Sermersheim Internet-Draft - Expires Jun 2004 Page 16 - Lightweight Directory Access Protocol Version 3 - unexpectedly failed or been compromised, or that the server now requires the client to authenticate using a strong(er) mechanism. - unavailable: This server will stop accepting new connections and operations on all existing connections, and be unavailable for an + +Sermersheim Internet-Draft - Expires Jul 2004 Page 16 + Lightweight Directory Access Protocol Version 3 + extended period of time. The client may make use of an alternative server. - Upon transmission of the UnbindRequest, each protocol peer is to + Upon transmission of the Notice of Disconnection, the server is to consider the LDAP association terminated, MUST cease transmission of - messages to the other peer, and MUST close the connection. + messages to the client, and MUST close the connection. 4.5. Search Operation 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 entry, or a whole subtree of entries. 4.5.1. Search Request @@ -934,98 +928,99 @@ -- constrained to below Filter ::= CHOICE { and [0] SET SIZE (1..MAX) OF filter Filter, or [1] SET SIZE (1..MAX) OF filter Filter, not [2] Filter, equalityMatch [3] AttributeValueAssertion, substrings [4] SubstringFilter, greaterOrEqual [5] AttributeValueAssertion, lessOrEqual [6] AttributeValueAssertion, - -Sermersheim Internet-Draft - Expires Jun 2004 Page 17 - Lightweight Directory Access Protocol Version 3 - present [7] AttributeDescription, approxMatch [8] AttributeValueAssertion, extensibleMatch [9] MatchingRuleAssertion } SubstringFilter ::= SEQUENCE { + +Sermersheim Internet-Draft - Expires Jul 2004 Page 17 + Lightweight Directory Access Protocol Version 3 + 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, any [1] AssertionValue, final [2] AssertionValue } } MatchingRuleAssertion ::= SEQUENCE { matchingRule [1] MatchingRuleId OPTIONAL, type [2] AttributeDescription OPTIONAL, matchValue [3] AssertionValue, dnAttributes [4] BOOLEAN DEFAULT FALSE } - Parameters of the Search Request are: + Fields of the Search Request are: - baseObject: The name of the base object entry 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. - oneLevel: The scope is constrained to the immediate + 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. + wholeSubtree: the scope is constrained to the entry named by + the baseObject, and all its subordinates. - - derefAliases: An indicator as to how alias objects (as defined in - [X.501]) are to be handled in searching. The semantics of the + - 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 - object 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 detect looping in this process to prevent denial of - service attacks and duplicate entries. + neverDerefAliases: Do not dereference aliases in searching or + in locating the base object of the search. -Sermersheim Internet-Draft - Expires Jun 2004 Page 18 - Lightweight Directory Access Protocol Version 3 + 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. - derefFindingBaseObj: Dereference aliases in locating the - base object of the search, but not when searching - subordinates of the base object. + 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. +Sermersheim Internet-Draft - Expires Jul 2004 Page 18 + Lightweight Directory Access Protocol Version 3 + + 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 enforce a - maximum number of entries to return. + 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 enforce a maximum time limit - for the search. + 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. @@ -1043,86 +1038,93 @@ 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" + 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. The present match evaluates to TRUE where there is an attribute or - -Sermersheim Internet-Draft - Expires Jun 2004 Page 19 - Lightweight Directory Access Protocol Version 3 - subtype of the specified attribute description present in an entry, and FALSE otherwise (including a presence test with an unrecognized attribute description.) +Sermersheim Internet-Draft - Expires Jul 2004 Page 19 + Lightweight Directory Access Protocol Version 3 + 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 MUST - conform 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. The entire SubstringFilter - is converted into an assertion value of the substrings matching - rule prior to applying the rule. + 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 greaterOrEqual and lessOrEqual filter items - is defined by the ORDERING matching rule for the attribute type. + The matching rule for the greaterOrEqual filter item is defined by + the ORDERING and EQUALITY matching rules for the attribute type. - The approxMatch 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, this filter item should be treated as an equalityMatch. + The matching rule for the lessOrEqual filter item is defined by + the ORDERING matching rule for the attribute type. - An extensibleMatch is evaluated as follows: + 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, this filter item should be treated as an + equalityMatch. + + An extensibleMatch filter item is evaluated as follows: 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 suitable for use with the specified type (see [Syntaxes]), - otherwise the filter item is undefined. + 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 -Sermersheim Internet-Draft - Expires Jun 2004 Page 20 +Sermersheim Internet-Draft - Expires Jul 2004 Page 20 Lightweight Directory Access Protocol Version 3 + 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. If an attribute description in an equalityMatch, substrings, greaterOrEqual, lessOrEqual, approxMatch or extensibleMatch filter is not recognized by the server, a matching rule id in the extensibleMatch is not recognized by the server, the assertion value is invalid, or the type of filtering requested is not implemented, then the filter is Undefined. Thus for example if a @@ -1132,62 +1134,64 @@ 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 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)]: + ([ABNF]): attributeSelection = noattrs / *( attributedescription / specialattr ) noattrs = %x31 %x2E %x31 ; "1.1" specialattr = ASTERISK ASTERISK = %x2A ; asterisk ("*") - is defined in Section 2.5 of [Models]. + The production is defined in Section 2.5 of + [Models]. There are two special values which may be used: an empty list with no attributes, and the attribute description string "*". Both of these signify that all user attributes are to be returned. (The "*" allows the client to request all user attributes in addition to any specified operational attributes). Client implementors should note that even if all user attributes are requested, some - attributes and or attribute values of the entry may not be + 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 MUST NOT be named more than once in the list, and are + +Sermersheim Internet-Draft - Expires Jul 2004 Page 21 + Lightweight Directory Access Protocol Version 3 + returned at most once in an entry. If there are attribute descriptions in the list which are not recognized, they are ignored by the server. -Sermersheim Internet-Draft - Expires Jun 2004 Page 21 - Lightweight Directory Access Protocol Version 3 - If the client does not want any attributes returned, it can specify a list containing only the attribute with OID "1.1". This OID was chosen because it does not (and can not) correspond to any attribute in use. 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 + 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. 4.5.2. Search Result The results of the search operation are returned as zero or more searchResultEntry messages, zero or more SearchResultReference @@ -1214,55 +1218,56 @@ 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 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 errors that have occurred. Each entry returned in a SearchResultEntry will contain all appropriate attributes as specified in the attributes field of the + +Sermersheim Internet-Draft - Expires Jul 2004 Page 22 + Lightweight Directory Access Protocol Version 3 + Search Request. Return of attributes is subject to access control and other administrative policy. Some attributes may be constructed by the server and appear in a SearchResultEntry attribute list, although they are not stored - -Sermersheim Internet-Draft - Expires Jun 2004 Page 22 - Lightweight Directory Access Protocol Version 3 - attributes of an entry. Clients SHOULD NOT assume that all attributes can be modified, even if permitted by access control. If the server's schema defines short names [Models] for an attribute type then the server SHOULD use one of those names in attribute descriptions for that attribute type (in preference to using the [Models] format of the attribute type's object identifier). The server SHOULD NOT use the short name if that name is known by the server to be ambiguous, or otherwise likely to cause interoperability problems. 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 all the entries in the scope at - and subordinate to the baseObject, 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 a referral result code. + 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 a referral + result code. If a server holds a copy or partial copy of the subordinate naming - context, 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. + 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 an association between a client and @@ -1270,399 +1275,417 @@ wishes to individually. 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. +Sermersheim Internet-Draft - Expires Jul 2004 Page 23 + Lightweight Directory Access Protocol Version 3 + When an LDAP URL is used, the following instructions are followed: + - The part of the URL MUST be present, with the new target object name. The client MUST use this name when following the - referral. Note that UTF-8 characters appearing in a DN or search - filter may not be legal for URLs (e.g. spaces) and MUST be - escaped using the % method in [URI]. - -Sermersheim Internet-Draft - Expires Jun 2004 Page 23 - Lightweight Directory Access Protocol Version 3 - - - It is RECOMMENDED that the part be present to avoid - ambiguity. + 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]. - Some servers (e.g. participating in distributed indexing) may provide a different filter in a URL of a SearchResultReference. - 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 originating search scope was singleLevel, the - part of the URL will be "base". + 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 originating search scope was singleLevel, the part + of the URL will be "base". - it is RECOMMENDED that the part be present to avoid ambiguity. - - 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 search request may be the same as or different from the search request which generated the SearchResultReference. - - The name of an unexplored subtree in a SearchResultReference - need not be subordinate to the base object. + - 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 ignore URIs that they - do not support. + URIs is left to future specifications. Clients may ignore URIs that + they do not support. -4.5.3.1. Example +4.5.3.1. Examples For example, suppose the contacted server (hosta) holds the entry - "DC=Example,DC=NET" and the entry "CN=Manager,DC=Example,DC=NET". It + and the entry . It knows that either LDAP-capable servers (hostb) or (hostc) hold - "OU=People,DC=Example,DC=NET" (one is the master and the other server + (one is the master and the other server a shadow), and that LDAP-capable server (hostd) holds the subtree - "OU=Roles,DC=Example,DC=NET". If a subtree search of - "DC=Example,DC=NET" is requested to the contacted server, it may + . If a wholeSubtree search of + is requested to the contacted server, it may return the following: SearchResultEntry for DC=Example,DC=NET SearchResultEntry for CN=Manager,DC=Example,DC=NET SearchResultReference { ldap://hostb/OU=People,DC=Example,DC=NET??sub ldap://hostc/OU=People,DC=Example,DC=NET??sub } SearchResultReference { ldap://hostd/OU=Roles,DC=Example,DC=NET??sub } SearchResultDone (success) 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 - "OU=People,DC=Example,DC=NET", the server might respond as follows: + , the server might respond as follows: + +Sermersheim Internet-Draft - Expires Jul 2004 Page 24 + Lightweight Directory Access Protocol Version 3 SearchResultEntry for OU=People,DC=Example,DC=NET SearchResultReference { ldap://hoste/OU=Managers,OU=People,DC=Example,DC=NET??sub } + SearchResultReference { + ldap://hostf/OU=Consultants,OU=People,DC=Example,DC=NET??sub } + SearchResultDone (success) -Sermersheim Internet-Draft - Expires Jun 2004 Page 24 - Lightweight Directory Access Protocol Version 3 + 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://hostf/OU=Consultants,OU=People,DC=Example,DC=NET??sub } + ldap://hostb/OU=People,DC=Example,DC=NET??base + ldap://hostc/OU=People,DC=Example,DC=NET??base } + SearchResultReference { + ldap://hostd/OU=Roles,DC=Example,DC=NET??base } SearchResultDone (success) If the contacted server does not hold the base object for the search, then it will return a referral to the client. For example, if the - client requests a subtree search of "DC=Example,DC=ORG" to hosta, the + client requests a subtree search of to hosta, the server may return only a SearchResultDone containing a referral. SearchResultDone (referral) { ldap://hostg/DC=Example,DC=ORG??sub } 4.6. Modify Operation 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: ModifyRequest ::= [APPLICATION 6] SEQUENCE { object LDAPDN, changes SEQUENCE OF change SEQUENCE { operation ENUMERATED { add (0), delete (1), replace (2) }, modification PartialAttribute } } - Parameters of the Modify Request are: + 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. - changes: A list of modifications to be performed on the entry. The entire list of modifications MUST be performed in the order they - are listed, as a single atomic operation. While individual + are listed as a single atomic operation. While individual modifications may violate certain aspects of the directory schema (such as the object class definition and DIT content rule), the + +Sermersheim Internet-Draft - Expires Jul 2004 Page 25 + Lightweight Directory Access Protocol Version 3 + resulting entry after the entire list of modifications is - performed MUST conform to the requirements of the directory - schema. + performed MUST conform to the requirements of the directory schema + [Models]. - operation: Used to specify the type of modification being performed. Each operation type acts on the following modification. The values of this field have the following semantics respectively: 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 - -Sermersheim Internet-Draft - Expires Jun 2004 Page 25 - Lightweight Directory Access Protocol Version 3 - - listed, or if all current values of the attribute are - listed for deletion; + 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; 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 delete the entire attribute if it exists, and is - ignored if the attribute does not exist. + attribute with the new values listed, creating the attribute + if it did not already exist. A replace with no value will + delete the entire attribute if it exists, and is ignored if + the attribute does not exist. - - modification: A PartialAttribute (which may have an empty SET of - vals) used to hold the attribute type or attribute type and + - modification: A PartialAttribute (which may have an empty SET + of vals) used to hold the attribute type or attribute type and values being modified. Upon receipt of a Modify Request, the server attempts to perform the necessary modifications to the DIT and returns the result in a Modify Response, defined as follows: ModifyResponse ::= [APPLICATION 7] LDAPResult The server will return to the client a single Modify Response indicating either the successful completion of the DIT modification, - or the reason that the modification failed. Note that due to the - requirement for atomicity in applying the list of modifications in - the Modify Request, the client may expect that no modifications of - the DIT have 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. If the association changes or the connection - fails, whether the modification occurred or not is indeterminate. + or the reason that the modification failed. Due to the requirement + for atomicity in applying the list of modifications in the Modify + Request, the client may expect that no modifications of the DIT have + 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. If the association changes or the connection fails, + whether the modification occurred or not is indeterminate. 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. Note that due to the simplifications made in LDAP, there is not a direct mapping of the changes in an LDAP ModifyRequest onto the changes of a DAP ModifyEntry operation, and different implementations of LDAP-DAP gateways may use different means of representing the + +Sermersheim Internet-Draft - Expires Jul 2004 Page 26 + Lightweight Directory Access Protocol Version 3 + change. If successful, the final effect of the operations on the entry MUST be identical. 4.7. Add Operation 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 { entry LDAPDN, attributes AttributeList } AttributeList ::= SEQUENCE OF attribute Attribute -Sermersheim Internet-Draft - Expires Jun 2004 Page 26 - Lightweight Directory Access Protocol Version 3 - - Parameters of the Add Request are: + Fields of the Add Request are: - - entry: the name of the entry to be added. Note that the server - SHALL NOT dereference any aliases in locating the entry to be - added. + - 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 make up the content of the entry being added. Clients MUST include distinguished values - (those forming the entry's own RDN) in this list, 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. + (those forming the entry's own RDN) in this list, 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. The entry named in the entry field of the AddRequest MUST NOT exist for the AddRequest to succeed. The immediate superior (parent) of an object or alias entry to be added MUST exist. For example, if the - client attempted to add "CN=JS,DC=Example,DC=NET", the - "DC=Example,DC=NET" entry did not exist, and the "DC=NET" entry did + client attempted to add , the + entry did not exist, and the entry did exist, then the server would return the noSuchObject result code with - the matchedDN field containing "DC=NET". If the parent entry exists - but is not in a naming context held by the server, the server SHOULD - return a referral to the server holding the parent entry. + the matchedDN field containing . If the parent entry exists + but is not in a naming context [Section 5 of Models] held by the + server, the server SHOULD return a referral to the server holding the + parent entry. 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 the client in the Add Response, defined as follows: AddResponse ::= [APPLICATION 9] LDAPResult - A response of success indicates that the new entry is present in the - Directory. + A response of success indicates that the new entry has been added to + the Directory. + +Sermersheim Internet-Draft - Expires Jul 2004 Page 27 + Lightweight Directory Access Protocol Version 3 4.8. Delete Operation 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 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. Only leaf entries (those with no subordinate entries) can be deleted with this operation. -Sermersheim Internet-Draft - Expires Jun 2004 Page 27 - Lightweight Directory Access Protocol Version 3 - Upon receipt of a Delete Request, a server will attempt to perform the entry removal requested and return the result in the Delete Response defined as follows: DelResponse ::= [APPLICATION 11] LDAPResult 4.9. Modify DN Operation 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: ModifyDNRequest ::= [APPLICATION 12] SEQUENCE { entry LDAPDN, newrdn RelativeLDAPDN, deleteoldrdn BOOLEAN, newSuperior [0] LDAPDN OPTIONAL } - Parameters of the Modify DN Request are: + Fields of the Modify DN Request are: - entry: the name of the entry to be changed. This entry may or may - not have subordinate entries. Note that the server SHALL NOT - dereference any aliases in locating the entry to be changed. + not have subordinate entries. - newrdn: the new RDN of the entry. - - deleteoldrdn: a boolean parameter that controls whether the old - RDN attribute values are to be retained as attributes of the - entry, or deleted from the entry. + - deleteoldrdn: a boolean field that controls whether the old RDN + attribute values are to be retained as attributes of the entry, or + deleted from the entry. - newSuperior: if present, this is the name of an existing object entry which becomes the immediate superior (parent) of the existing entry. + The server SHALL NOT dereference any aliases in locating the objects + named in entry or newSuperior. + +Sermersheim Internet-Draft - Expires Jul 2004 Page 28 + Lightweight Directory Access Protocol Version 3 + Upon receipt of a ModifyDNRequest, a server will attempt to perform the name change and return the result in the Modify DN Response, defined as follows: ModifyDNResponse ::= [APPLICATION 13] LDAPResult - For example, if the entry named in the "entry" parameter was "cn=John - Smith,c=US", the newrdn parameter was "cn=John Cougar Smith", and the - newSuperior parameter was absent, then this operation would attempt - to rename the entry to be "cn=John Cougar Smith,c=US". If there was + For example, if the entry named in the entry field was , the newrdn field was , and the + newSuperior field was absent, then this operation would attempt to + rename the entry to be . If there was already an entry with that name, the operation would fail with the entryAlreadyExists result code. The object named in newSuperior MUST exist. For example, if the - client attempted to add "CN=JS,DC=Example,DC=NET", the - "DC=Example,DC=NET" entry did not exist, and the "DC=NET" entry did + client attempted to add , the + entry did not exist, and the entry did exist, then the server would return the noSuchObject result code with - the matchedDN field containing "DC=NET". - -Sermersheim Internet-Draft - Expires Jun 2004 Page 28 - Lightweight Directory Access Protocol Version 3 + the matchedDN field containing . - If the deleteoldrdn parameter is TRUE, the values forming the old RDN - are deleted from the entry. If the deleteoldrdn parameter is FALSE, - the 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 - parameter would cause a schema inconsistency in the entry. + 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. Note that X.500 restricts the ModifyDN operation to only affect entries that are contained within a single server. If the LDAP server is mapped onto DAP, then this restriction will apply, and the affectsMultipleDSAs result code will be returned if this error occurred. In general, clients MUST NOT expect to be able to perform arbitrary movements of entries and subtrees between servers or between naming contexts. 4.10. Compare Operation - The Compare Operation allows a client to compare an assertion - provided with an entry in the Directory. The Compare Request is - defined as follows: + 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: CompareRequest ::= [APPLICATION 14] SEQUENCE { entry LDAPDN, ava AttributeValueAssertion } - Parameters of the Compare Request are: + Fields of the Compare Request are: - - entry: the name of the entry to be compared. Note that the server - SHALL NOT dereference any aliases in locating the entry to be - compared. + - entry: the name of the entry to be compared. The server SHALL NOT + dereference any aliases in locating the entry to be compared. - - ava: the assertion with which an attribute in the entry is to be - compared. + - ava: holds the attribute description and assertion value with + which an attribute in the entry is to be compared. + +Sermersheim Internet-Draft - Expires Jul 2004 Page 29 + Lightweight Directory Access Protocol Version 3 Upon receipt of a Compare Request, a server will attempt to perform - the requested comparison using the EQUALITY matching rule for the - attribute type and return the result in the Compare Response, defined - as follows: + the requested comparison and return the result in the Compare + Response, defined as follows: CompareResponse ::= [APPLICATION 15] LDAPResult + If the operation succeeds (e.g. the attribute or subtype is present + and access controls allow comparison), the resultCode field will be + compareTrue if the assertion value in the ava field is equivalent to + any value of the attribute or subtype (according to the attribute's + EQUALITY matching rule). Otherwise compareFalse is returned in the + resultCode field. + In the event that the attribute or subtype is not present in the entry, the resultCode field is set to noSuchAttribute. If the attribute is unknown, the resultCode is set to undefinedAttributeType. Note that errors and the result of comparison are all returned in the same construct. 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. -Sermersheim Internet-Draft - Expires Jun 2004 Page 29 - Lightweight Directory Access Protocol Version 3 - 4.11. Abandon Operation The function of the Abandon Operation is to allow a client to request that the server abandon an outstanding operation. The Abandon Request is defined as follows: AbandonRequest ::= [APPLICATION 16] MessageID - The MessageID MUST be that of an operation which was requested - earlier in this LDAP association. The abandon request itself has its - own message id. This is distinct from the id of the earlier operation - being abandoned. + The MessageID is that of an operation which was requested earlier in + this LDAP association. The abandon request itself has its own message + id. This is distinct from the id 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 by the MessageID. Operation responses are not sent for successfully abandoned operations, thus the application of the Abandon operation is limited to uses where the client does not require an indication of its outcome. - Abandon and Unbind operations cannot be abandoned. The ability to - abandon other (particularly update) operations is at the discretion - of the server. + Abandon, Bind, Unbind, and StartTLS operations cannot be abandoned. + The ability to abandon other (particularly update) operations is at + the discretion of the server. In the event that a server receives an Abandon Request on a Search 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 course, the server MUST ensure that only properly encoded LDAPMessage PDUs are transmitted. - Clients MUST NOT send abandon requests for the same operation +Sermersheim Internet-Draft - Expires Jul 2004 Page 30 + Lightweight Directory Access Protocol Version 3 + + 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). 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 @@ -1670,243 +1693,249 @@ services not already available in the protocol. For example, to add operations to install transport layer security (see Section 4.13). 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. -Sermersheim Internet-Draft - Expires Jun 2004 Page 30 - Lightweight Directory Access Protocol Version 3 - ExtendedRequest ::= [APPLICATION 23] SEQUENCE { requestName [0] LDAPOID, requestValue [1] OCTET STRING OPTIONAL } The requestName is a dotted-decimal representation of the unique OBJECT IDENTIFIER corresponding to the request. The requestValue is information in a form defined by that request, encapsulated inside an OCTET STRING. - The server will respond to this with an LDAPMessage containing the + The server will respond to this with an LDAPMessage containing an ExtendedResponse. ExtendedResponse ::= [APPLICATION 24] SEQUENCE { COMPONENTS OF LDAPResult, responseName [10] LDAPOID OPTIONAL, responseValue [11] OCTET STRING OPTIONAL } The responseName is typically not required to be present as the syntax and semantics of the response (including the format of the responseValue) is implicitly known and associated with the request by the messageID. If the requestName is not recognized by the server, the server MUST NOT provide a responseName nor a responseValue and MUST return a resultCode of 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 be prepared to handle arbitrary contents of these fields, including + +Sermersheim Internet-Draft - Expires Jul 2004 Page 31 + Lightweight Directory Access Protocol Version 3 + zero bytes. Values that are defined in terms of ASN.1 and BER encoded according to Section 5.1, also follow the extensibility rules in Section 4. It is RECOMMENDED that servers list the requestName of extended - operations they support in the supportedExtension attribute [Models] - of the root DSE. + operations they support in the 'supportedExtension' attribute of the + root DSE [Models]. Extended operations may be specified in other documents. The specification of an extended operation consists of: - the OBJECT IDENTIFIER assigned to the requestName (and possibly responseName), - the format of the contents of the requestValue and responseValue - (if any), + (if any), and - - the semantics of the operation, + - the semantics of the operation. 4.13. StartTLS Operation -Sermersheim Internet-Draft - Expires Jun 2004 Page 31 - Lightweight Directory Access Protocol Version 3 - The Start Transport Layer Security (StartTLS) operation provides the ability to establish Transport Layer Security ([TLS]) on an LDAP connection. The StartTLS operation is defined using the extended operation mechanism described in Section 4.12. 4.13.1. StartTLS Request A client requests TLS establishment by transmitting a StartTLS request PDU to the server. The StartTLS request is defined in terms 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 connection following this - request until it receives a StartTLS extended response. + request until it receives a StartTLS extended response and completes + TLS negotiations. 4.13.2. StartTLS Response When a StartTLS request is made, servers supporting the operation - MUST return a StartTLS response PDU to the requestor. The StartTLS - response responseName is also "1.3.6.1.4.1.1466.20037", and the - response field is absent. + MUST return a StartTLS response PDU to the requestor. The + responseName is also "1.3.6.1.4.1.1466.20037", and the responseValue + field is absent. - The server MUST set the resultCode field to either success or one of + The server provides a resultCode field to either success or one of the other values outlined in Section 4.13.2.2. 4.13.2.1. "Success" Response - If the StartTLS Response contains a result code of success, this + If the StartTLS Response contains a resultCode of success, this indicates that the server is willing and able to negotiate TLS. Refer - to Section 5.3 of [AuthMeth] for details. + to Section 4 of [AuthMeth] for details. + +Sermersheim Internet-Draft - Expires Jul 2004 Page 32 + Lightweight Directory Access Protocol Version 3 4.13.2.2. Response other than "success" If the ExtendedResponse contains a result code other than success, this indicates that the server is unwilling or unable to negotiate TLS. The following result codes have these meanings for this operation: - operationsError: operations sequencing incorrect; e.g. TLS is already established. - protocolError: TLS is not supported or incorrect PDU structure. - unavailable: Some major problem with TLS, or the server is shutting down. The server MUST return operationsError if the client violates any of the StartTLS extended operation sequencing requirements described in - Section 5.3 of [AuthMeth]. + Section 4 of [AuthMeth]. If the server does not support TLS (whether by design or by current - configuration), it MUST set the resultCode field to protocolError. - The client's current association is unaffected if the server does not - -Sermersheim Internet-Draft - Expires Jun 2004 Page 32 - Lightweight Directory Access Protocol Version 3 - + configuration), it MUST return the protocolError resultCode. The + client's current association is unaffected if the server does not support TLS. The client may proceed with any LDAP operation, or it may close the connection. The server MUST return unavailable if it supports TLS but cannot establish a TLS connection for some reason, e.g. the certificate server not responding, it cannot contact its TLS implementation, or if the server is in process of shutting down. The client may retry the StartTLS operation, or it may proceed with any other LDAP operation, or it may close the LDAP connection. 4.13.3. Closing a TLS Connection Two forms of TLS connection closure -- graceful and abrupt -- are - supported. + supported. These do not involve LDAP PDUs, but are preformed at the + underlying layers. 4.13.3.1. Graceful Closure Either the client or server MAY terminate the TLS connection and leave the LDAP connection 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 connection intact, it then MUST cease to send further PDUs and MUST ignore any received 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. +Sermersheim Internet-Draft - Expires Jul 2004 Page 33 + Lightweight Directory Access Protocol Version 3 + When a protocol peer receives the initial TLS closure alert, it may - choose to allow the underlying LDAP connection 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 underlying LDAP connection to remain intact. In + this case, it MUST immediately transmit a TLS closure alert. + Following this, it MAY send and receive LDAP PDUs. Protocol peers MAY drop the underlying LDAP connection after sending or receiving a TLS closure alert. After the TLS connection has been closed, the server MUST NOT send responses to any request message received before the TLS closure. Thus, clients wishing to receive responses to messages sent while the TLS connection is intact MUST wait for those message responses before sending the TLS closure alert. 4.13.3.2. Abrupt Closure Either the client or server MAY abruptly close the TLS connection by dropping the underlying transfer protocol connection. In this circumstance, a server MAY send the client a Notice of Disconnection - before dropping the underlying LDAP connection. + before dropping the underlying LDAP connection. Outstanding + operations are handled as specified in Section 5.2. 5. Protocol Element Encodings and Transfer -Sermersheim Internet-Draft - Expires Jun 2004 Page 33 - Lightweight Directory Access Protocol Version 3 - One underlying service, LDAP over TCP, is defined here. This service is generally applicable to applications providing or consuming X.500- based directory services on the Internet. Implementations of LDAP over TCP MUST implement the mapping as described in Section 5.2.1 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: - (1) Only the definite form of length encoding is used. + - Only the definite form of length encoding is used. - (2) OCTET STRING values are encoded in the primitive form only. + - OCTET STRING values are encoded in the primitive form only. - (3) If the value of a BOOLEAN type is true, the encoding of the - value octet is set to hex "FF". + - If the value of a BOOLEAN type is true, the encoding of the value + octet is set to hex "FF". - (4) If a value of a type is its default value, it is absent. Only - some BOOLEAN and INTEGER types have default values in this - protocol definition. + - If a value of a type is its default value, it is absent. Only some + BOOLEAN and INTEGER types have default values in this protocol + definition. These restrictions are meant to ease the overhead of encoding and decoding certain elements in BER. +Sermersheim Internet-Draft - Expires Jul 2004 Page 34 + Lightweight Directory Access Protocol Version 3 + These restrictions do not apply to ASN.1 types encapsulated inside of OCTET STRING values, such as attribute values, unless otherwise stated. 5.2. Transfer Protocols This protocol is designed to run over connection-oriented, reliable transports, with all 8 bits in an octet being significant in the data - stream. + stream. Protocol operations are tied to a connection, thus if the + connection is closed or dropped, the operation is aborted. When this + happens, any outstanding operations on the server are, when possible, + abandoned, and when not possible, completed without transmission of + the response. Also, if the connection is closed or dropped, the + client MUST NOT assume that any outstanding requests which modified + the Directory have succeeded or failed. 5.2.1. Transmission Control Protocol (TCP) The encoded LDAPMessage PDUs are mapped directly onto the [TCP] 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 assigned port, 389. Servers may + provide a protocol listener on the Internet Assigned Numbers + Authority (IANA)-assigned LDAP port, 389 [PortReg]. Servers may instead provide a listener on a different port number. Clients MUST support contacting servers on any valid TCP port. 6. Security Considerations This version of the protocol provides facilities for simple authentication using a cleartext password, as well as any [SASL] - -Sermersheim Internet-Draft - Expires Jun 2004 Page 34 - Lightweight Directory Access Protocol Version 3 - mechanism. SASL allows for integrity and privacy services to be negotiated. It is also permitted that the server can return its credentials to the client, if it chooses to do so. Use of cleartext password is strongly discouraged where the underlying transport service cannot guarantee confidentiality and may result in disclosure of the password to unauthorized parties. @@ -1914,77 +1943,80 @@ that have authenticated anonymously [AuthMeth]. Requirements of authentication methods, SASL mechanisms, and TLS are described in [AuthMeth]. 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 + +Sermersheim Internet-Draft - Expires Jul 2004 Page 35 + Lightweight Directory Access Protocol Version 3 + contained in these fields SHOULD NOT be relied on unless otherwise protected (such as by establishing protections at the transport layer). Server implementors should plan for the possibility of an identity associated with an LDAP connection being deleted, renamed, or modified, and take appropriate actions to prevent insecure side effects. Likewise, server implementors should plan for the possibility of an associated identity's credentials becoming invalid, - or an identities privileges being changed. The way in which these - issues are addressed are application - and/or implementation specific. + or an identity's privileges being changed. The ways in which these + issues are addressed are application and/or implementation specific. Implementations which cache attributes and entries obtained via LDAP 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 example, caches could serve result information only to the client whose request caused it to be in the cache. - Protocol servers may return referrals which redirect protocol 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. Protocol clients are advised to be aware of - this, and possibly reject referrals when confidentiality measures are - not in place. Protocol clients are advised to reject referrals from - the StartTLS operation. + 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 + to be aware of this, and possibly reject referrals when + confidentiality measures are not in place. Clients are advised to + reject referrals from the StartTLS operation. Protocol peers MUST be prepared to handle invalid and arbitrary length protocol encodings. A number of LDAP security advisories are available through [CERT]. -Sermersheim Internet-Draft - Expires Jun 2004 Page 35 - Lightweight Directory Access Protocol Version 3 - 7. Acknowledgements - This document updates RFC 2251 by Mark Wahl, Tim Howes, and Steve - Kille. It also updates RFC 2830 by Jeff Hodges, RL "Bob" Morgan, and - Mark Wahl. Their work along with the input of individuals of the IETF - ASID, LDAPEXT, LDUP, LDAPBIS, and other Working Groups is gratefully - acknowledged. + This document is based on RFC 2251 by Mark Wahl, Tim Howes, and Steve + Kille. It is also based on RFC 2830 by Jeff Hodges, RL "Bob" Morgan, + and Mark Wahl. Their work along with the input of individuals of the + IETF ASID, LDAPEXT, LDUP, LDAPBIS, and other Working Groups is + gratefully acknowledged. 8. Normative References [ABNF] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [ASN.1] ITU-T Recommendation X.680 (07/2002) | ISO/IEC 8824-1:2002 "Information Technology - Abstract Syntax Notation One (ASN.1): Specification of basic notation" [AuthMeth] Harrison, R., "LDAP: Authentication Methods and Connection Level Security Mechanisms ", draft-ietf-ldapbis-authmeth- xx.txt, (a work in progress). +Sermersheim Internet-Draft - Expires Jul 2004 Page 36 + Lightweight Directory Access Protocol Version 3 + [BER] ITU-T Rec. X.690 (07/2002) | ISO/IEC 8825-1:2002, "Information technology - ASN.1 encoding rules: Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER)", 2002. [IP] Postel, J., "Internet Protocol", STD5 and RFC 791, September 1981 [ISO10646] Universal Multiple-Octet Coded Character Set (UCS) - @@ -2003,23 +2035,20 @@ [LDAPURL] Smith, M., "LDAP: Uniform Resource Locator", draft-ietf- ldapbis-url-xx.txt, (a work in progress). [Models] Zeilenga, K., "LDAP: Directory Information Models", draft- ietf-ldapbis-models-xx.txt (a work in progress). [Roadmap] Zeilenga, K., "LDAP: Technical Specification Road Map", draft-ietf-ldapbis-roadmap-xx.txt (a work in progress). -Sermersheim Internet-Draft - Expires Jun 2004 Page 36 - Lightweight Directory Access Protocol Version 3 - [SASL] Melnikov, A., "Simple Authentication and Security Layer", draft-ietf-sasl-rfc2222bis-xx.txt (a work in progress). [SASLPrep] Zeilenga, K., "Stringprep profile for user names and passwords", draft-ietf-sasl-saslprep-xx.txt, (a work in progress). [StringPrep] Hoffman P. and M. Blanchet, "Preparation of Internationalized Strings ('stringprep')", draft-hoffman- rfc3454bis-xx.txt, a work in progress. @@ -2027,125 +2056,136 @@ [Syntaxes] Legg, S., and K. Dally, "LDAP: Syntaxes and Matching Rules", draft-ietf-ldapbis-syntaxes-xx.txt, (a work in progress). [TCP] Postel, J., "Transmission Control Protocol", STD7 and RFC 793, September 1981 [TLS] Dierks, T. and C. Allen. "The TLS Protocol Version 1.1", draft-ietf-tls-rfc2246-bis-xx.txt, a work in progress. +Sermersheim Internet-Draft - Expires Jul 2004 Page 37 + Lightweight Directory Access Protocol Version 3 + [Unicode] The Unicode Consortium, "The Unicode Standard, Version 3.2.0" is defined by "The Unicode Standard, Version 3.0" (Reading, MA, Addison-Wesley, 2000. ISBN 0-201-61633-5), as amended by the "Unicode Standard Annex #27: Unicode 3.1" (http://www.unicode.org/reports/tr27/) and by the "Unicode Standard Annex #28: Unicode 3.2" (http://www.unicode.org/reports/tr28/). - [URI] Berners-Lee, T., Fielding, R., and L. Masinter Uniform + [URI] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax", RFC 2396, August 1998. - [UTF-8] Yergeau, F., "UTF-8, a transformation format of Unicode - and ISO 10646", STD63 and RFC3629. + [UTF-8] Yergeau, F., "UTF-8, a transformation format of ISO + 10646", STD63 and RFC3629, November 2003. [X.500] ITU-T Rec. X.500, "The Directory: Overview of Concepts, Models and Service", 1993. [X.501] ITU-T Rec. X.501, "The Directory: Models", 1993. [X.511] ITU-T Rec. X.511, "The Directory: Abstract Service Definition", 1993. 9. Informative References - [CERT] the CERT(R) Center, (http://www.cert.org) + [CERT] The CERT(R) Center, http://www.cert.org -10. IANA Considerations + [PortReg] IANA, "Port Numbers", + http://www.iana.org/assignments/port-numbers -Sermersheim Internet-Draft - Expires Jun 2004 Page 37 - Lightweight Directory Access Protocol Version 3 +10. IANA Considerations It is requested that the Internet Assigned Numbers Authority (IANA) - update the occurrence of "RFC XXXX" in Appendix B with this RFC - number at publication. + update the LDAP result code registry to indicate that this document + provides the definitive technical specification for result codes 0- + 36, 48-54, 64-70, 80-90. + + 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 Start TLS + (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. 11. Editor's Address Jim Sermersheim Novell, Inc. 1800 South Novell Place Provo, Utah 84606, USA jimse@novell.com +1 801 861-3088 -Sermersheim Internet-Draft - Expires Jun 2004 Page 38 +Sermersheim Internet-Draft - Expires Jul 2004 Page 38 Lightweight Directory Access Protocol Version 3 Appendix A - LDAP Result Codes This normative appendix details additional considerations regarding LDAP result codes and provides a brief, general description of each - LDAP result code enumerated in Section 4.1.10. + LDAP result code enumerated in Section 4.1.9. Additional result codes MAY be defined for use with extensions [LDAPIANA]. Client implementations SHALL treat any result code which they do not recognize as an unknown error condition. A.1 Non-Error Result Codes These result codes (called "non-error" result codes) do not indicate an error condition: success (0), compareTrue (6), compareFalse (7), referral (10), and saslBindInProgress (14). - The success, compareTrue, and compare result codes indicate + The success, compareTrue, and compareFalse result codes indicate successful completion (and, hence, are referred to as "successful" result codes). The referral and saslBindInProgress result codes indicate the client - is required to take additional action to complete the operation + is required to take additional action to complete the operation. A.2 Result Codes Existing LDAP result codes are described as follows: success (0) Indicates the successful completion of an operation. Note: this code is not used with the compare operation. See compareTrue (5) and compareFalse (6). operationsError (1) Indicates that the operation is not properly sequenced with relation to other operations (of same or different type). For example, this code is returned if the client attempts to - StartTLS [RFC2246] while there are other operations - outstanding or if TLS was already established. + StartTLS [TLS] while there are other operations outstanding + or if TLS was already established. protocolError (2) Indicates the server received data which has incorrect structure. For bind operation only, this code is also used to indicate that the server does not support the requested protocol version. - timeLimitExceeded (3) - -Sermersheim Internet-Draft - Expires Jun 2004 Page 39 +Sermersheim Internet-Draft - Expires Jul 2004 Page 39 Lightweight Directory Access Protocol Version 3 + timeLimitExceeded (3) Indicates that the time limit specified by the client was exceeded before the operation could be completed. sizeLimitExceeded (4) Indicates that the size limit specified by the client was exceeded before the operation could be completed. compareFalse (5) Indicates that the compare operation has successfully completed and the assertion has evaluated to FALSE. @@ -2160,52 +2200,52 @@ 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. referral (10) Indicates that a referral needs to be chased to complete the - operation (see Section 4.1.11). + operation (see Section 4.1.10). adminLimitExceeded (11) Indicates that an administrative limit has been exceeded. unavailableCriticalExtension (12) Indicates that the server is unable or unwilling to perform a - critical extension (see Section 4.1.12). + critical control (see Section 4.1.11). confidentialityRequired (13) Indicates that data confidentiality protections are required. saslBindInProgress (14) 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). noSuchAttribute (16) Indicates that the named entry does not contain the specified attribute or attribute value. undefinedAttributeType (17) Indicates that a request field contains an unrecognized attribute description. - inappropriateMatching (18) - -Sermersheim Internet-Draft - Expires Jun 2004 Page 40 +Sermersheim Internet-Draft - Expires Jul 2004 Page 40 Lightweight Directory Access Protocol Version 3 - Indicates that an attempt was made, e.g. in a filter, to use - a matching rule not defined for the attribute type concerned. + inappropriateMatching (18) + Indicates that an attempt was made, e.g. in an assertion, to + use a matching rule not defined for the attribute type + concerned. constraintViolation (19) Indicates that the client supplied an attribute value which does not conform to the constraints placed upon it by the data model. For example, this code is returned when multiple values are supplied to an attribute which has a SINGLE-VALUE constraint. attributeOrValueExists (20) @@ -2243,25 +2283,24 @@ provide some form of credentials. invalidCredentials (49) Indicates that the provided credentials (e.g. the user's name and password) are invalid. insufficientAccessRights (50) Indicates that the client does not have sufficient access rights to perform the operation. - busy (51) - -Sermersheim Internet-Draft - Expires Jun 2004 Page 41 +Sermersheim Internet-Draft - Expires Jul 2004 Page 41 Lightweight Directory Access Protocol Version 3 + busy (51) Indicates that the server is too busy to service the operation. unavailable (52) Indicates that the server is shutting down or a subsystem necessary to complete the operation is offline. unwillingToPerform (53) Indicates that the server is unwilling to perform the operation. @@ -2283,33 +2322,33 @@ Indicates that the operation is inappropriately attempting to remove a value which forms the entry's relative distinguished name. entryAlreadyExists (68) Indicates that the request cannot be fulfilled (added, moved, or renamed) as the target entry already exists. objectClassModsProhibited (69) Indicates that an attempt to modify the object class(es) of - an entry's objectClass attribute is prohibited. + 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. affectsMultipleDSAs (71) Indicates that the operation cannot be completed as it affects multiple servers (DSAs). other (80) Indicates the server has encountered an internal error. -Sermersheim Internet-Draft - Expires Jun 2004 Page 42 +Sermersheim Internet-Draft - Expires Jul 2004 Page 42 Lightweight Directory Access Protocol Version 3 Appendix B - Complete ASN.1 Definition This appendix is normative. Lightweight-Directory-Access-Protocol-V3 -- Copyright (C) The Internet Society (2003). This version of -- this ASN.1 module is part of RFC XXXX; see the RFC itself -- for full legal notices. @@ -2347,29 +2386,30 @@ MessageID ::= INTEGER (0 .. maxInt) maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- LDAPString ::= OCTET STRING -- UTF-8 encoded, -- [ISO10646] characters LDAPOID ::= OCTET STRING -- Constrained to [Models] - LDAPDN ::= LDAPString - - RelativeLDAPDN ::= LDAPString + LDAPDN ::= LDAPString -- Constrained to + -- [LDAPDN] - AttributeDescription ::= LDAPString + RelativeLDAPDN ::= LDAPString -- Constrained to + -- [LDAPDN] -Sermersheim Internet-Draft - Expires Jun 2004 Page 43 +Sermersheim Internet-Draft - Expires Jul 2004 Page 43 Lightweight Directory Access Protocol Version 3 + AttributeDescription ::= LDAPString -- Constrained to -- [Models] AttributeValue ::= OCTET STRING AttributeValueAssertion ::= SEQUENCE { attributeDesc AttributeDescription, assertionValue AssertionValue } AssertionValue ::= OCTET STRING @@ -2408,43 +2448,42 @@ attributeOrValueExists (20), invalidAttributeSyntax (21), -- 22-31 unused -- noSuchObject (32), aliasProblem (33), invalidDNSyntax (34), -- 35 reserved for undefined isLeaf -- aliasDereferencingProblem (36), -- 37-47 unused -- inappropriateAuthentication (48), - invalidCredentials (49), - insufficientAccessRights (50), -Sermersheim Internet-Draft - Expires Jun 2004 Page 44 +Sermersheim Internet-Draft - Expires Jul 2004 Page 44 Lightweight Directory Access Protocol Version 3 + invalidCredentials (49), + insufficientAccessRights (50), busy (51), unavailable (52), unwillingToPerform (53), loopDetect (54), -- 55-63 unused -- namingViolation (64), objectClassViolation (65), notAllowedOnNonLeaf (66), notAllowedOnRDN (67), entryAlreadyExists (68), objectClassModsProhibited (69), -- 70 reserved for CLDAP -- affectsMultipleDSAs (71), -- 72-79 unused -- other (80), ... }, - -- 81-90 reserved for APIs -- matchedDN LDAPDN, diagnosticMessage LDAPString, referral [3] Referral OPTIONAL } Referral ::= SEQUENCE SIZE (1..MAX) OF uri URI URI ::= LDAPString -- limited to characters permitted in -- URIs Controls ::= SEQUENCE OF control Control @@ -2468,41 +2507,43 @@ SaslCredentials ::= SEQUENCE { mechanism LDAPString, credentials OCTET STRING OPTIONAL } BindResponse ::= [APPLICATION 1] SEQUENCE { COMPONENTS OF LDAPResult, serverSaslCreds [7] OCTET STRING OPTIONAL } UnbindRequest ::= [APPLICATION 2] NULL -Sermersheim Internet-Draft - Expires Jun 2004 Page 45 +Sermersheim Internet-Draft - Expires Jul 2004 Page 45 Lightweight Directory Access Protocol Version 3 SearchRequest ::= [APPLICATION 3] SEQUENCE { baseObject LDAPDN, scope ENUMERATED { baseObject (0), singleLevel (1), wholeSubtree (2) }, derefAliases ENUMERATED { neverDerefAliases (0), derefInSearching (1), derefFindingBaseObj (2), derefAlways (3) }, sizeLimit INTEGER (0 .. maxInt), timeLimit INTEGER (0 .. maxInt), typesOnly BOOLEAN, filter Filter, attributes AttributeSelection } AttributeSelection ::= SEQUENCE OF selection LDAPString + -- constrained to + -- in section 4.5.1. Filter ::= CHOICE { and [0] SET SIZE (1..MAX) OF filter Filter, or [1] SET SIZE (1..MAX) OF filter Filter, not [2] Filter, equalityMatch [3] AttributeValueAssertion, substrings [4] SubstringFilter, greaterOrEqual [5] AttributeValueAssertion, lessOrEqual [6] AttributeValueAssertion, present [7] AttributeDescription, @@ -2522,27 +2563,27 @@ matchingRule [1] MatchingRuleId OPTIONAL, type [2] AttributeDescription OPTIONAL, matchValue [3] AssertionValue, dnAttributes [4] BOOLEAN DEFAULT FALSE } SearchResultEntry ::= [APPLICATION 4] SEQUENCE { objectName LDAPDN, attributes PartialAttributeList } PartialAttributeList ::= SEQUENCE OF - partialAttribute PartialAttribute - - SearchResultReference ::= [APPLICATION 19] SEQUENCE -Sermersheim Internet-Draft - Expires Jun 2004 Page 46 +Sermersheim Internet-Draft - Expires Jul 2004 Page 46 Lightweight Directory Access Protocol Version 3 + partialAttribute PartialAttribute + + SearchResultReference ::= [APPLICATION 19] SEQUENCE SIZE (1..MAX) OF uri URI SearchResultDone ::= [APPLICATION 5] LDAPResult ModifyRequest ::= [APPLICATION 6] SEQUENCE { object LDAPDN, changes SEQUENCE OF change SEQUENCE { operation ENUMERATED { add (0), delete (1), @@ -2581,23 +2622,26 @@ ExtendedRequest ::= [APPLICATION 23] SEQUENCE { requestName [0] LDAPOID, requestValue [1] OCTET STRING OPTIONAL } ExtendedResponse ::= [APPLICATION 24] SEQUENCE { COMPONENTS OF LDAPResult, responseName [10] LDAPOID OPTIONAL, responseValue [11] OCTET STRING OPTIONAL } +Sermersheim Internet-Draft - Expires Jul 2004 Page 47 + Lightweight Directory Access Protocol Version 3 + END -Sermersheim Internet-Draft - Expires Jun 2004 Page 47 +Sermersheim Internet-Draft - Expires Jul 2004 Page 48 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. C.1 Changes made to made to RFC 2251: @@ -2618,36 +2662,36 @@ - 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 - Clarified where the extensibility features of ASN.1 apply to the protocol. This change also affected various ASN.1 types. - Removed the requirement that servers which implement version 3 or - later MUST provide the supportedLDAPVersion attribute. This + later MUST provide the 'supportedLDAPVersion' attribute. This statement provided no interoperability advantages. C.1.4 Section 4.1.1 - 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. C.1.5 Section 4.1.1.1 - Clarified that the messageID of requests MUST be non-zero. -Sermersheim Internet-Draft - Expires Jun 2004 Page 48 +Sermersheim Internet-Draft - Expires Jul 2004 Page 49 Lightweight Directory Access Protocol Version 3 - Clarified 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 - Stated that LDAPOID is constrained to from [Models]. @@ -2684,42 +2728,44 @@ C.1.12 Section 4.1.11 - Defined referrals in terms of URIs rather than URLs. - Removed the requirement that all referral URIs MUST be equally capable of progressing the operation. The statement was ambiguous and provided no instructions on how to carry it out. - 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. -Sermersheim Internet-Draft - Expires Jun 2004 Page 49 +Sermersheim Internet-Draft - Expires Jul 2004 Page 50 Lightweight Directory Access Protocol Version 3 C.1.13 Section 4.1.12 - 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). - Added language regarding combinations of controls on a message. - Changed "The server MUST be prepared" to "Implementations MUST be prepared" in the eighth paragraph to reflect that both client and server implementations must be able to handle this (as both parse controls). C.1.14 Section 4.2 - Mandated that servers return protocolError when the version is not supported. - Clarified 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 added for consistency with other operations and to help ensure - data consistency + data consistency. - Required that textual passwords be transferred as UTF-8 encoded Unicode, and added recommendations on string preparation. This was to help ensure interoperability of passwords being sent from different clients. C.1.15 Section 4.2.1 - This section was largely reorganized for readability and language was added to clarify the authentication state of failed and abandoned bind operations. @@ -2734,44 +2780,47 @@ 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. - Dropped MUST imperative in paragraph 3 to align with [Keywords]. C.1.16 Section 4.2.3 - Moved most error-related text to Appendix A, and added text regarding certain errors used in conjunction with the bind operation. - - Prohibited the server from specifying serverSaslCreds when not - appropriate. -Sermersheim Internet-Draft - Expires Jun 2004 Page 50 +Sermersheim Internet-Draft - Expires Jul 2004 Page 51 Lightweight Directory Access Protocol Version 3 + - Prohibited the server from specifying serverSaslCreds when not + appropriate. + C.1.17 Section 4.3 - Required both peers to cease transmission and close the connection for the unbind operation. C.1.18 Section 4.4 - Added instructions for future specifications of Unsolicited Notifications. C.1.19 Section 4.5.1 - SearchRequest attributes is now defined as an AttributeSelection type rather than AttributeDescriptionList. - The Filter choices 'and' and 'or', and the SubstringFilter substrings types are now defined with a lower bound of 1. - The SubstringFilter substrings 'initial, 'any', and 'final' types - are now AssertionValue rather than LDAPString. + 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. - Added instructions for equalityMatch, substrings, greaterOrEqual, lessOrEqual, and approxMatch. C.1.20 Section 4.5.2 - Recommended that servers not use attribute short names when it knows they are ambiguous or may cause interoperability problems. - Removed all mention of ExtendedResponse due to lack of implementation. @@ -2779,51 +2828,51 @@ C.1.21 Section 4.5.3 - Made changes similar to those made to Section 4.1.11. C.1.22 Section 4.5.3.1 - Fixed examples to adhere to changes made to Section 4.5.3. C.1.23 Section 4.6 - - Removed restriction that required an equality match filter in + - Removed restriction that required an EQUALITY matching rule in order to perform value delete modifications. It is sufficiently + +Sermersheim Internet-Draft - Expires Jul 2004 Page 52 + Lightweight Directory Access Protocol Version 3 + documented that in absence of an equality matching rule, octet equality is used. - Replaced AttributeTypeAndValues with Attribute as they are equivalent. - -Sermersheim Internet-Draft - Expires Jun 2004 Page 51 - Lightweight Directory Access Protocol Version 3 - - Clarified what type of modification changes might temporarily violate schema. C.1.24 Section 4.9 - 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. C.1.25 Section 4.10 - Clarified the semantics of Compare when the attribute is not present and when it is unknown. - Required servers to not dereference aliases for compare. This was added for consistency with other operations and to help ensure data consistency. C.1.26 Section 4.11 - - Explained that since abandon returns no response, clients hould + - 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.1.27 Section 4.12 - Specified how values of extended operations defined in terms of ASN.1 are to be encoded. - Added instructions on what extended operation specifications consist of. - Added a recommendation that servers advertise supported extended @@ -2831,56 +2880,59 @@ C.1.28 Section 5.2 - Moved referral-specific instructions into referral-related sections. C.1.29 Section 7 - Reworded notes regarding SASL not protecting certain aspects of the LDAP bind PDU. + +Sermersheim Internet-Draft - Expires Jul 2004 Page 53 + Lightweight Directory Access Protocol Version 3 + - Noted that Servers are encouraged to prevent directory modifications by clients that have authenticated anonymously [AuthMeth]. - Added a note regarding the scenario where an identity is changed (deleted, privileges or credentials modified, etc.). - -Sermersheim Internet-Draft - Expires Jun 2004 Page 52 - Lightweight Directory Access Protocol Version 3 - - Warned against following referrals that may have been injected in the data stream. - Added a note regarding malformed and long encodings. C.1.30 Appendix A - Added "EXTESIBILITY IMPLIED" to ASN.1 definition. - Removed AttributeType. It is not used. C.2 Changes made to made to RFC 2830: This section summarizes the substantive changes made to Sections of RFC 2830. Readers should consult [AuthMeth] for summaries of changes to other sections. C.2.1 Section 2.3 - Removed wording indicating that referrals can be returned from 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 - 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. -Sermersheim Internet-Draft - Expires Jun 2004 Page 53 +Sermersheim Internet-Draft - Expires Jul 2004 Page 54 Lightweight Directory Access Protocol Version 3 Intellectual Property Rights The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the @@ -2918,12 +2970,10 @@ The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assigns. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. - -Sermersheim Internet-Draft - Expires Jun 2004 Page 54