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diff --git a/source4/ldap_server/devdocs/rfc2251.txt b/source4/ldap_server/devdocs/rfc2251.txt deleted file mode 100644 index 88844cbf38..0000000000 --- a/source4/ldap_server/devdocs/rfc2251.txt +++ /dev/null @@ -1,2803 +0,0 @@ - - - - - - -Network Working Group M. Wahl -Request for Comments: 2251 Critical Angle Inc. -Category: Standards Track T. Howes - Netscape Communications Corp. - S. Kille - Isode Limited - December 1997 - - - Lightweight Directory Access Protocol (v3) - -1. Status of this Memo - - This document specifies an Internet standards track protocol for the - Internet community, and requests discussion and suggestions for - improvements. Please refer to the current edition of the "Internet - Official Protocol Standards" (STD 1) for the standardization state - and status of this protocol. Distribution of this memo is unlimited. - -Copyright Notice - - Copyright (C) The Internet Society (1997). All Rights Reserved. - -IESG Note - - This document describes a directory access protocol that provides - both read and update access. Update access requires secure - authentication, but this document does not mandate implementation of - any satisfactory authentication mechanisms. - - In accordance with RFC 2026, section 4.4.1, this specification is - being approved by IESG as a Proposed Standard despite this - limitation, for the following reasons: - - a. to encourage implementation and interoperability testing of - these protocols (with or without update access) before they - are deployed, and - - b. to encourage deployment and use of these protocols in read-only - applications. (e.g. applications where LDAPv3 is used as - a query language for directories which are updated by some - secure mechanism other than LDAP), and - - c. to avoid delaying the advancement and deployment of other Internet - standards-track protocols which require the ability to query, but - not update, LDAPv3 directory servers. - - - - - -Wahl, et. al. Standards Track [Page 1] - -RFC 2251 LDAPv3 December 1997 - - - Readers are hereby warned that until mandatory authentication - mechanisms are standardized, clients and servers written according to - this specification which make use of update functionality are - UNLIKELY TO INTEROPERATE, or MAY INTEROPERATE ONLY IF AUTHENTICATION - IS REDUCED TO AN UNACCEPTABLY WEAK LEVEL. - - Implementors are hereby discouraged from deploying LDAPv3 clients or - servers which implement the update functionality, until a Proposed - Standard for mandatory authentication in LDAPv3 has been approved and - published as an RFC. - -Table of Contents - - 1. Status of this Memo .................................... 1 - Copyright Notice ....................................... 1 - IESG Note .............................................. 1 - 2. Abstract ............................................... 3 - 3. Models ................................................. 4 - 3.1. Protocol Model ........................................ 4 - 3.2. Data Model ............................................ 5 - 3.2.1. Attributes of Entries ............................... 5 - 3.2.2. Subschema Entries and Subentries .................... 7 - 3.3. Relationship to X.500 ................................. 8 - 3.4. Server-specific Data Requirements ..................... 8 - 4. Elements of Protocol ................................... 9 - 4.1. Common Elements ....................................... 9 - 4.1.1. Message Envelope .................................... 9 - 4.1.1.1. Message ID ........................................ 11 - 4.1.2. String Types ........................................ 11 - 4.1.3. Distinguished Name and Relative Distinguished Name .. 11 - 4.1.4. Attribute Type ...................................... 12 - 4.1.5. Attribute Description ............................... 13 - 4.1.5.1. Binary Option ..................................... 14 - 4.1.6. Attribute Value ..................................... 14 - 4.1.7. Attribute Value Assertion ........................... 15 - 4.1.8. Attribute ........................................... 15 - 4.1.9. Matching Rule Identifier ............................ 15 - 4.1.10. Result Message ..................................... 16 - 4.1.11. Referral ........................................... 18 - 4.1.12. Controls ........................................... 19 - 4.2. Bind Operation ........................................ 20 - 4.2.1. Sequencing of the Bind Request ...................... 21 - 4.2.2. Authentication and Other Security Services .......... 22 - 4.2.3. Bind Response ....................................... 23 - 4.3. Unbind Operation ...................................... 24 - 4.4. Unsolicited Notification .............................. 24 - 4.4.1. Notice of Disconnection ............................. 24 - 4.5. Search Operation ...................................... 25 - - - -Wahl, et. al. Standards Track [Page 2] - -RFC 2251 LDAPv3 December 1997 - - - 4.5.1. Search Request ...................................... 25 - 4.5.2. Search Result ....................................... 29 - 4.5.3. Continuation References in the Search Result ........ 31 - 4.5.3.1. Example ........................................... 31 - 4.6. Modify Operation ...................................... 32 - 4.7. Add Operation ......................................... 34 - 4.8. Delete Operation ...................................... 35 - 4.9. Modify DN Operation ................................... 36 - 4.10. Compare Operation .................................... 37 - 4.11. Abandon Operation .................................... 38 - 4.12. Extended Operation ................................... 38 - 5. Protocol Element Encodings and Transfer ................ 39 - 5.1. Mapping Onto BER-based Transport Services ............. 39 - 5.2. Transfer Protocols .................................... 40 - 5.2.1. Transmission Control Protocol (TCP) ................. 40 - 6. Implementation Guidelines .............................. 40 - 6.1. Server Implementations ................................ 40 - 6.2. Client Implementations ................................ 40 - 7. Security Considerations ................................ 41 - 8. Acknowledgements ....................................... 41 - 9. Bibliography ........................................... 41 - 10. Authors' Addresses ..................................... 42 - Appendix A - Complete ASN.1 Definition ..................... 44 - Full Copyright Statement ................................... 50 - -2. Abstract - - The protocol described in this document is designed to provide access - to directories supporting the X.500 models, while not incurring the - resource requirements of the X.500 Directory Access Protocol (DAP). - This protocol is specifically targeted at management applications and - browser applications that provide read/write interactive access to - directories. When used with a directory supporting the X.500 - protocols, it is intended to be a complement to the X.500 DAP. - - 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 RFC 2119 [10]. - - Key aspects of this version of LDAP are: - - - All protocol elements of LDAPv2 (RFC 1777) are supported. The - protocol is carried directly over TCP or other transport, bypassing - much of the session/presentation overhead of X.500 DAP. - - - Most protocol data elements can be encoded as ordinary strings - (e.g., Distinguished Names). - - - - -Wahl, et. al. Standards Track [Page 3] - -RFC 2251 LDAPv3 December 1997 - - - - Referrals to other servers may be returned. - - - SASL mechanisms may be used with LDAP to provide association - security services. - - - Attribute values and Distinguished Names have been - internationalized through the use of the ISO 10646 character set. - - - The protocol can be extended to support new operations, and - controls may be used to extend existing operations. - - - Schema is published in the directory for use by clients. - -3. Models - - Interest in X.500 [1] directory technologies in the Internet has led - to efforts to reduce the high cost of entry associated with use of - these technologies. This document continues the efforts to define - directory protocol alternatives, updating the LDAP [2] protocol - specification. - -3.1. 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 any results or - errors to the requesting client. - - In keeping with the goal of easing the costs associated with use of - the directory, it is an objective of this protocol to minimize the - complexity of clients so as to facilitate widespread deployment of - applications capable of using the directory. - - Note that 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. - - In LDAP versions 1 and 2, no provision was made for protocol servers - returning referrals to clients. However, for improved performance - and distribution this version of the protocol permits servers to - return to clients referrals to other servers. This allows servers to - offload the work of contacting other servers to progress operations. - - - -Wahl, et. al. Standards Track [Page 4] - -RFC 2251 LDAPv3 December 1997 - - - Note that the core protocol operations defined in this document can - be mapped to a strict subset of the X.500(1997) directory abstract - service, so it can be cleanly provided by the DAP. However there is - not a one-to-one mapping between LDAP protocol operations and DAP - operations: server implementations acting as a gateway to X.500 - directories may need to make multiple DAP requests. - -3.2. Data Model - - This section provides a brief introduction to the X.500 data model, - as used by LDAP. - - The LDAP protocol assumes there are one or more servers which jointly - provide access to a Directory Information Tree (DIT). The tree is - made up of entries. Entries have names: one or more attribute values - from the entry form its relative distinguished name (RDN), which MUST - be unique among all its siblings. The concatenation of the relative - distinguished names of the sequence of entries from a particular - entry to an immediate subordinate of the root of the tree forms that - entry's Distinguished Name (DN), which is unique in the tree. An - example of a Distinguished Name is - - CN=Steve Kille, O=Isode Limited, C=GB - - Some servers may hold cache or shadow copies of entries, which can be - used to answer search and comparison queries, but will return - referrals or contact other servers if modification operations are - requested. - - Servers which perform caching or shadowing MUST ensure that they do - not violate any access control constraints placed on the data by the - originating server. - - The largest collection of entries, starting at an entry that is - mastered by a particular server, and including all its subordinates - and their subordinates, down to the entries which are mastered by - different servers, is termed a naming context. The root of the DIT - is a DSA-specific Entry (DSE) and not part of any naming context: - each server has different attribute values in the root DSE. (DSA is - an X.500 term for the directory server). - -3.2.1. Attributes of Entries - - Entries consist of a set of attributes. An attribute is a type with - one or more associated values. The attribute type is identified by a - short descriptive name and an OID (object identifier). The attribute - - - - - -Wahl, et. al. Standards Track [Page 5] - -RFC 2251 LDAPv3 December 1997 - - - type governs whether there can be more than one value of an attribute - of that type in an entry, the syntax to which the values must - conform, the kinds of matching which can be performed on values of - that attribute, and other functions. - - An example of an attribute is "mail". There may be one or more values - of this attribute, they must be IA5 (ASCII) strings, and they are - case insensitive (e.g. "foo@bar.com" will match "FOO@BAR.COM"). - - Schema is the collection of attribute type definitions, object class - definitions and other information which a server uses to determine - how to match a filter or attribute value assertion (in a compare - operation) against the attributes of an entry, and whether to permit - add and modify operations. The definition of schema for use with - LDAP is given in [5] and [6]. Additional schema elements may be - defined in other documents. - - Each entry MUST have an objectClass attribute. The objectClass - attribute specifies the object classes of an entry, which along with - the system and user schema determine the permitted attributes of an - entry. Values of this attribute may be modified by clients, but the - objectClass attribute cannot be removed. Servers may restrict the - modifications of this attribute to prevent the basic structural class - of the entry from being changed (e.g. one cannot change a person into - a country). When creating an entry or adding an objectClass value to - an entry, all superclasses of the named classes are implicitly added - as well if not already present, and the client must supply values for - any mandatory attributes of new superclasses. - - Some attributes, termed operational attributes, are used by servers - for administering the directory system itself. They are not returned - in search results unless explicitly requested by name. Attributes - which are not operational, such as "mail", will have their schema and - syntax constraints enforced by servers, but servers will generally - not make use of their values. - - Servers MUST NOT permit clients to add attributes to an entry unless - those attributes are permitted by the object class definitions, the - schema controlling that entry (specified in the subschema - see - below), or are operational attributes known to that server and used - for administrative purposes. Note that there is a particular - objectClass 'extensibleObject' defined in [5] which permits all user - attributes to be present in an entry. - - Entries MAY contain, among others, the following operational - attributes, defined in [5]. These attributes are maintained - automatically by the server and are not modifiable by clients: - - - - -Wahl, et. al. Standards Track [Page 6] - -RFC 2251 LDAPv3 December 1997 - - - - creatorsName: the Distinguished Name of the user who added this - entry to the directory. - - - createTimestamp: the time this entry was added to the directory. - - - modifiersName: the Distinguished Name of the user who last modified - this entry. - - - modifyTimestamp: the time this entry was last modified. - - - subschemaSubentry: the Distinguished Name of the subschema entry - (or subentry) which controls the schema for this entry. - -3.2.2. Subschema Entries and Subentries - - Subschema entries are used for administering information about the - directory schema, in particular the object classes and attribute - types supported by directory servers. A single subschema entry - contains all schema definitions used by entries in a particular part - of the directory tree. - - Servers which follow X.500(93) models SHOULD implement subschema - using the X.500 subschema mechanisms, and so these subschemas are not - ordinary entries. LDAP clients SHOULD NOT assume that servers - implement any of the other aspects of X.500 subschema. A server - which masters entries and permits clients to modify these entries - MUST implement and provide access to these subschema entries, so that - its clients may discover the attributes and object classes which are - permitted to be present. It is strongly recommended that all other - servers implement this as well. - - The following four attributes MUST be present in all subschema - entries: - - - cn: this attribute MUST be used to form the RDN of the subschema - entry. - - - objectClass: the attribute MUST have at least the values "top" and - "subschema". - - - objectClasses: each value of this attribute specifies an object - class known to the server. - - - attributeTypes: each value of this attribute specifies an attribute - type known to the server. - - These are defined in [5]. Other attributes MAY be present in - subschema entries, to reflect additional supported capabilities. - - - -Wahl, et. al. Standards Track [Page 7] - -RFC 2251 LDAPv3 December 1997 - - - These include matchingRules, matchingRuleUse, dITStructureRules, - dITContentRules, nameForms and ldapSyntaxes. - - Servers SHOULD provide the attributes createTimestamp and - modifyTimestamp in subschema entries, in order to allow clients to - maintain their caches of schema information. - - Clients MUST only retrieve attributes from a subschema entry by - requesting a base object search of the entry, where the search filter - is "(objectClass=subschema)". (This will allow LDAPv3 servers which - gateway to X.500(93) to detect that subentry information is being - requested.) - -3.3. Relationship to X.500 - - This document defines LDAP in terms of X.500 as an X.500 access - mechanism. An LDAP server MUST act in accordance with the - X.500(1993) series of ITU recommendations when providing the service. - However, it is not required that an LDAP server make use of any X.500 - protocols in providing this service, e.g. LDAP can be mapped onto any - other directory system so long as the X.500 data and service model as - used in LDAP is not violated in the LDAP interface. - -3.4. Server-specific Data Requirements - - An LDAP server MUST provide information about itself and other - information that is specific to each server. This is represented as - a group of attributes located in the root DSE (DSA-Specific Entry), - which is named with the zero-length LDAPDN. These attributes are - retrievable if a client performs a base object search of the root - with filter "(objectClass=*)", however they are subject to access - control restrictions. The root DSE MUST NOT be included if the - client performs a subtree search starting from the root. - - Servers may allow clients to modify these attributes. - - The following attributes of the root DSE are defined in section 5 of - [5]. Additional attributes may be defined in other documents. - - - namingContexts: naming contexts held in the server. Naming contexts - are defined in section 17 of X.501 [6]. - - - subschemaSubentry: subschema entries (or subentries) known by this - server. - - - altServer: alternative servers in case this one is later - unavailable. - - - - -Wahl, et. al. Standards Track [Page 8] - -RFC 2251 LDAPv3 December 1997 - - - - supportedExtension: list of supported extended operations. - - - supportedControl: list of supported controls. - - - supportedSASLMechanisms: list of supported SASL security features. - - - supportedLDAPVersion: LDAP versions implemented by the server. - - If the server does not master entries and does not know the locations - of schema information, the subschemaSubentry attribute is not present - in the root DSE. If the server masters directory entries under one - or more schema rules, there may be any number of values of the - subschemaSubentry attribute in the root DSE. - -4. Elements of Protocol - - The LDAP protocol is described using Abstract Syntax Notation 1 - (ASN.1) [3], and is typically transferred using a subset of ASN.1 - Basic Encoding Rules [11]. In order to support future extensions to - this protocol, clients and servers MUST ignore elements of SEQUENCE - encodings whose tags they do not recognize. - - Note that unlike X.500, each change to the LDAP protocol other than - through the extension mechanisms will have a different version - number. A client will indicate the version it supports as part of - the bind request, described in section 4.2. If a client has not sent - a bind, the server MUST assume that version 3 is supported in the - client (since version 2 required that the client bind first). - - Clients may determine the protocol version a server supports by - reading the supportedLDAPVersion attribute from the root DSE. Servers - which implement version 3 or later versions MUST provide this - attribute. Servers which only implement version 2 may not provide - this attribute. - -4.1. Common Elements - - This section describes the LDAPMessage envelope PDU (Protocol Data - Unit) 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 { - - - -Wahl, et. al. Standards Track [Page 9] - -RFC 2251 LDAPv3 December 1997 - - - messageID MessageID, - protocolOp CHOICE { - bindRequest BindRequest, - bindResponse BindResponse, - unbindRequest UnbindRequest, - searchRequest SearchRequest, - searchResEntry SearchResultEntry, - searchResDone SearchResultDone, - searchResRef SearchResultReference, - modifyRequest ModifyRequest, - modifyResponse ModifyResponse, - addRequest AddRequest, - addResponse AddResponse, - delRequest DelRequest, - delResponse DelResponse, - modDNRequest ModifyDNRequest, - modDNResponse ModifyDNResponse, - compareRequest CompareRequest, - compareResponse CompareResponse, - abandonRequest AbandonRequest, - extendedReq ExtendedRequest, - extendedResp ExtendedResponse }, - controls [0] Controls OPTIONAL } - - MessageID ::= INTEGER (0 .. maxInt) - - maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- - - 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 MUST return the notice of disconnection - described in section 4.4.1, with resultCode protocolError, and - immediately close the connection. In other cases that the server - cannot parse the request received by the client, the server MUST - return an appropriate response to the request, with the resultCode - set to protocolError. - - If the client receives a PDU from the server which cannot be parsed, - the client may discard the PDU, or may abruptly close the connection. - - The ASN.1 type Controls is defined in section 4.1.12. - - - - -Wahl, et. al. Standards Track [Page 10] - -RFC 2251 LDAPv3 December 1997 - - -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 value different from the - values of any other requests outstanding in the LDAP session of which - this message is a part. - - A client MUST NOT send a second request with the same message ID as - an earlier request on the same connection if the client has not - received the final response from the earlier request. Otherwise the - behavior is undefined. Typical clients increment a counter for each - request. - - A client MUST NOT reuse the message id of an abandonRequest or of the - abandoned operation until it has received a response from the server - for another request invoked subsequent to the abandonRequest, as the - abandonRequest itself does not have a response. - -4.1.2. String Types - - The LDAPString is a notational convenience to indicate that, although - strings of LDAPString type encode as OCTET STRING types, the ISO - 10646 [13] character set (a superset of Unicode) is used, encoded - following the UTF-8 algorithm [14]. Note that in the UTF-8 algorithm - characters which are the same as ASCII (0x0000 through 0x007F) are - represented as that same ASCII character in a single byte. The other - byte values are used to form a variable-length encoding of an - arbitrary character. - - LDAPString ::= OCTET STRING - - 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. - - LDAPOID ::= OCTET STRING - - For example, - - 1.3.6.1.4.1.1466.1.2.3 - -4.1.3. Distinguished Name and Relative Distinguished Name - - An LDAPDN and a RelativeLDAPDN are respectively defined to be the - representation of a Distinguished Name and a Relative Distinguished - Name after encoding according to the specification in [4], such that - - - -Wahl, et. al. Standards Track [Page 11] - -RFC 2251 LDAPv3 December 1997 - - - <distinguished-name> ::= <name> - - <relative-distinguished-name> ::= <name-component> - - where <name> and <name-component> are as defined in [4]. - - LDAPDN ::= LDAPString - - RelativeLDAPDN ::= LDAPString - - Only Attribute Types can be present in a relative distinguished name - component; the options of Attribute Descriptions (next section) MUST - NOT be used in specifying distinguished names. - -4.1.4. Attribute Type - - An AttributeType takes on as its value the textual string associated - with that AttributeType in its specification. - - AttributeType ::= LDAPString - - Each attribute type has a unique OBJECT IDENTIFIER which has been - assigned to it. This identifier may be written as decimal digits - with components separated by periods, e.g. "2.5.4.10". - - A specification may also assign one or more textual names for an - attribute type. These names MUST begin with a letter, and only - contain ASCII letters, digit characters and hyphens. They are case - insensitive. (These ASCII characters are identical to ISO 10646 - characters whose UTF-8 encoding is a single byte between 0x00 and - 0x7F.) - - If the server has a textual name for an attribute type, it MUST use a - textual name for attributes returned in search results. The dotted- - decimal OBJECT IDENTIFIER is only used if there is no textual name - for an attribute type. - - Attribute type textual names are non-unique, as two different - specifications (neither in standards track RFCs) may choose the same - name. - - A server which masters or shadows entries SHOULD list all the - attribute types it supports in the subschema entries, using the - attributeTypes attribute. Servers which support an open-ended set of - attributes SHOULD include at least the attributeTypes value for the - 'objectClass' attribute. Clients MAY retrieve the attributeTypes - value from subschema entries in order to obtain the OBJECT IDENTIFIER - and other information associated with attribute types. - - - -Wahl, et. al. Standards Track [Page 12] - -RFC 2251 LDAPv3 December 1997 - - - Some attribute type names which are used in this version of LDAP are - described in [5]. Servers may implement additional attribute types. - -4.1.5. Attribute Description - - An AttributeDescription is a superset of the definition of the - AttributeType. It has the same ASN.1 definition, but allows - additional options to be specified. They are also case insensitive. - - AttributeDescription ::= LDAPString - - A value of AttributeDescription is based on the following BNF: - - <AttributeDescription> ::= <AttributeType> [ ";" <options> ] - - <options> ::= <option> | <option> ";" <options> - - <option> ::= <opt-char> <opt-char>* - - <opt-char> ::= ASCII-equivalent letters, numbers and hyphen - - Examples of valid AttributeDescription: - - cn - userCertificate;binary - - One option, "binary", is defined in this document. Additional - options may be defined in IETF standards-track and experimental RFCs. - Options beginning with "x-" are reserved for private experiments. - Any option could be associated with any AttributeType, although not - all combinations may be supported by a server. - - An AttributeDescription with one or more options is treated as a - subtype of the attribute type without any options. Options present - in an AttributeDescription are never mutually exclusive. - Implementations MUST generate the <options> list sorted in ascending - order, and servers MUST treat any two AttributeDescription with the - same AttributeType and options as equivalent. A server will treat an - AttributeDescription with any options it does not implement as an - unrecognized attribute type. - - The data type "AttributeDescriptionList" describes a list of 0 or - more attribute types. (A list of zero elements has special - significance in the Search request.) - - AttributeDescriptionList ::= SEQUENCE OF - AttributeDescription - - - - -Wahl, et. al. Standards Track [Page 13] - -RFC 2251 LDAPv3 December 1997 - - -4.1.5.1. Binary Option - - If the "binary" option is present in an AttributeDescription, it - overrides any string-based encoding representation defined for that - attribute in [5]. Instead the attribute is to be transferred as a - binary value encoded using the Basic Encoding Rules [11]. The syntax - of the binary value is an ASN.1 data type definition which is - referenced by the "SYNTAX" part of the attribute type definition. - - The presence or absence of the "binary" option only affects the - transfer of attribute values in protocol; servers store any - particular attribute in a single format. If a client requests that a - server return an attribute in the binary format, but the server - cannot generate that format, the server MUST treat this attribute - type as an unrecognized attribute type. Similarly, clients MUST NOT - expect servers to return an attribute in binary format if the client - requested that attribute by name without the binary option. - - This option is intended to be used with attributes whose syntax is a - complex ASN.1 data type, and the structure of values of that type is - needed by clients. Examples of this kind of syntax are "Certificate" - and "CertificateList". - -4.1.6. Attribute Value - - A field of type AttributeValue takes on as its value either a string - encoding of a AttributeValue data type, or an OCTET STRING containing - an encoded binary value, depending on whether the "binary" option is - present in the companion AttributeDescription to this AttributeValue. - - The definition of string encodings for different syntaxes and types - may be found in other documents, and in particular [5]. - - 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). - - Attributes may be defined which have arbitrary and non-printable - syntax. Implementations MUST NEITHER simply display nor attempt to - decode as ASN.1 a value if its syntax is not known. The - implementation may attempt to discover the subschema of the source - entry, and retrieve the values of attributeTypes from it. - - Clients MUST NOT send attribute values in a request which are not - valid according to the syntax defined for the attributes. - - - - -Wahl, et. al. Standards Track [Page 14] - -RFC 2251 LDAPv3 December 1997 - - -4.1.7. 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. - - AttributeValueAssertion ::= SEQUENCE { - attributeDesc AttributeDescription, - assertionValue AssertionValue } - - AssertionValue ::= OCTET STRING - - If the "binary" option is present in attributeDesc, this signals to - the server that the assertionValue is a binary encoding of the - assertion value. - - For all the string-valued user attributes described in [5], the - assertion value syntax is the same as the value syntax. Clients may - use attribute values as assertion values in compare requests and - search filters. - - Note however that the assertion syntax may be different from the - value syntax for other attributes or for non-equality matching rules. - These may have an assertion syntax which contains only part of the - value. See section 20.2.1.8 of X.501 [6] for examples. - -4.1.8. Attribute - - An attribute consists of a type and one or more values of that type. - (Though attributes MUST have at least one value when stored, due to - access control restrictions the set may be empty when transferred in - protocol. This is described in section 4.5.2, concerning the - PartialAttributeList type.) - - Attribute ::= SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - Each attribute value is distinct in the set (no duplicates). The - order of attribute values within the vals set is undefined and - implementation-dependent, and MUST NOT be relied upon. - -4.1.9. Matching Rule Identifier - - A matching rule is a means of expressing how a server should compare - an AssertionValue received in a search filter with an abstract data - value. The matching rule defines the syntax of the assertion value - and the process to be performed in the server. - - - -Wahl, et. al. Standards Track [Page 15] - -RFC 2251 LDAPv3 December 1997 - - - An X.501(1993) Matching Rule is identified in the LDAP protocol by - the printable representation of its OBJECT IDENTIFIER, either as one - of the strings given in [5], or as decimal digits with components - separated by periods, e.g. "caseIgnoreIA5Match" or - "1.3.6.1.4.1.453.33.33". - - MatchingRuleId ::= LDAPString - - Servers which support matching rules for use in the extensibleMatch - search filter MUST list the matching rules they implement in - subschema entries, using the matchingRules attributes. The server - SHOULD also list there, using the matchingRuleUse attribute, the - attribute types with which each matching rule can be used. More - information is given in section 4.4 of [5]. - -4.1.10. Result Message - - The LDAPResult is the construct used in this protocol to return - success or failure indications from servers to clients. In response - to various requests servers will return responses containing fields - of type 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), - - authMethodNotSupported (7), - strongAuthRequired (8), - -- 9 reserved -- - referral (10), -- new - adminLimitExceeded (11), -- new - unavailableCriticalExtension (12), -- new - confidentialityRequired (13), -- new - saslBindInProgress (14), -- new - noSuchAttribute (16), - undefinedAttributeType (17), - inappropriateMatching (18), - constraintViolation (19), - attributeOrValueExists (20), - invalidAttributeSyntax (21), - -- 22-31 unused -- - - - -Wahl, et. al. Standards Track [Page 16] - -RFC 2251 LDAPv3 December 1997 - - - noSuchObject (32), - aliasProblem (33), - invalidDNSyntax (34), - -- 35 reserved for undefined isLeaf -- - aliasDereferencingProblem (36), - -- 37-47 unused -- - inappropriateAuthentication (48), - 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), -- new - -- 72-79 unused -- - other (80) }, - -- 81-90 reserved for APIs -- - matchedDN LDAPDN, - errorMessage LDAPString, - referral [3] Referral OPTIONAL } - - All the result codes with the exception of success, compareFalse and - compareTrue are to be treated as meaning the operation could not be - completed in its entirety. - - Most of the result codes are based on problem indications from X.511 - error data types. Result codes from 16 to 21 indicate an - AttributeProblem, codes 32, 33, 34 and 36 indicate a NameProblem, - codes 48, 49 and 50 indicate a SecurityProblem, codes 51 to 54 - indicate a ServiceProblem, and codes 64 to 69 and 71 indicates an - UpdateProblem. - - If a client receives a result code which is not listed above, it is - to be treated as an unknown error condition. - - The errorMessage 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) - error diagnostic. As this error diagnostic is not standardized, - - - - -Wahl, et. al. Standards Track [Page 17] - -RFC 2251 LDAPv3 December 1997 - - - implementations MUST NOT rely on the values returned. If the server - chooses not to return a textual diagnostic, the errorMessage field of - the LDAPResult type MUST contain a zero length string. - - For result codes of 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 [8]. The matchedDN field is to be set to a zero length - string with all other result codes. - -4.1.11. Referral - - The referral error indicates that the contacted server does not hold - the target entry of the request. The referral field is present in an - LDAPResult if the LDAPResult.resultCode field value is referral, and - absent with all other result codes. It contains a reference to - another server (or set of servers) which 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 URL MUST be present in the Referral. - - The referral is not returned for a singleLevel or wholeSubtree search - in which the search scope spans multiple naming contexts, and several - different servers would need to be contacted to complete the - operation. Instead, continuation references, described in section - 4.5.3, are returned. - - Referral ::= SEQUENCE OF LDAPURL -- one or more - - LDAPURL ::= LDAPString -- limited to characters permitted in URLs - - If the client wishes to progress the operation, it MUST follow the - referral by contacting any one of servers. All the URLs MUST be - equally capable of being used to progress the operation. (The - mechanisms for how this is achieved by multiple servers are outside - the scope of this document.) - - URLs for servers implementing the LDAP protocol are written according - to [9]. If an alias was dereferenced, the <dn> part of the URL MUST - be present, with the new target object name. If the <dn> 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 referral for a search operation. If the filter part of the URL - - - -Wahl, et. al. Standards Track [Page 18] - -RFC 2251 LDAPv3 December 1997 - - - is present in an LDAPURL, 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. Other aspects - of the new request may be the same or different as the request which - generated 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 RFC 1738 [7]. - - Other kinds of URLs may be returned, so long as the operation could - be performed using that protocol. - -4.1.12. Controls - - A control is a way to specify extension information. Controls which - are sent as part of a request apply only to that request and are not - saved. - - Controls ::= SEQUENCE OF Control - - Control ::= SEQUENCE { - controlType LDAPOID, - criticality BOOLEAN DEFAULT FALSE, - controlValue OCTET STRING OPTIONAL } - - The controlType field MUST be a UTF-8 encoded dotted-decimal - representation of an OBJECT IDENTIFIER which uniquely identifies the - control. This prevents conflicts between control names. - - The criticality field is either TRUE or FALSE. - - 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. - - If the server does not recognize the control type and the criticality - field is TRUE, the server MUST NOT perform the operation, and MUST - instead return the resultCode unsupportedCriticalExtension. - - If the control is not appropriate for the operation and criticality - field is TRUE, the server MUST NOT perform the operation, and MUST - instead return the resultCode unsupportedCriticalExtension. - - If the control is unrecognized or inappropriate but the criticality - field is FALSE, the server MUST ignore the control. - - - - - -Wahl, et. al. Standards Track [Page 19] - -RFC 2251 LDAPv3 December 1997 - - - The controlValue contains any information associated with the - control, and its format is defined for the control. The server 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. - - This document does not define any controls. Controls may be defined - in other documents. The definition of a control consists of: - - - the OBJECT IDENTIFIER assigned to the control, - - - whether the control is always noncritical, always critical, or - critical at the client's option, - - - the format of the controlValue contents of the control. - - Servers list the controls which they recognize in the - supportedControl attribute in the root DSE. - -4.2. Bind Operation - - The function of the Bind Operation is to allow authentication - information to be exchanged between the client and server. - - 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: - - - version: A version number indicating the version of the protocol to - be used in this protocol session. This document describes version - 3 of the LDAP protocol. Note that there is no version negotiation, - and the client just sets this parameter to the version it desires. - If the client requests protocol version 2, a server that supports - the version 2 protocol as described in [2] will not return any v3- - - - -Wahl, et. al. Standards Track [Page 20] - -RFC 2251 LDAPv3 December 1997 - - - specific protocol fields. (Note that not all LDAP servers will - support protocol version 2, since they may be unable to generate - the attribute syntaxes associated with version 2.) - - - 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, when authentication - has been performed at a lower layer, or when using SASL credentials - with a mechanism that includes the LDAPDN in the credentials. - - - authentication: information used to authenticate the name, if any, - provided in the Bind Request. - - Upon receipt of a Bind Request, a protocol server will authenticate - the requesting client, if necessary. The server will then return a - Bind Response to the client indicating the status of the - authentication. - - 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 lower layer security - services. - -4.2.1. Sequencing of the Bind Request - - For some SASL authentication mechanisms, it may be necessary for the - client to invoke the BindRequest multiple times. 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. - - 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. - - Unlike LDAP v2, the client need not send a Bind Request in the first - PDU of the connection. The client may request any operations and the - server MUST treat these as unauthenticated. If the server requires - that the client bind before browsing or modifying the directory, the - server MAY reject a request other than binding, unbinding or an - extended request with the "operationsError" result. - - - - -Wahl, et. al. Standards Track [Page 21] - -RFC 2251 LDAPv3 December 1997 - - - If the client did not bind before sending a request and receives an - operationsError, it may then send a Bind Request. If this also fails - or the client chooses not to bind on the existing connection, it will - close the connection, reopen it and begin again by first sending a - PDU with a Bind Request. This will aid in interoperating with - servers implementing other versions of LDAP. - - Clients MAY send multiple bind requests on a connection to change - their credentials. A subsequent bind process has the effect of - abandoning all operations outstanding on the connection. (This - simplifies server implementation.) Authentication from earlier binds - are subsequently ignored, and so if the bind fails, the connection - will be treated as anonymous. If a SASL transfer encryption or - integrity mechanism has been negotiated, and that mechanism does not - support the changing of credentials from one identity to another, - then the client MUST instead establish a new connection. - -4.2.2. Authentication and Other Security Services - - The simple authentication option provides minimal authentication - facilities, with the contents of the authentication field consisting - only of a cleartext password. Note that the use of cleartext - passwords is not recommended over open networks when there is no - authentication or encryption being performed by a lower layer; see - the "Security Considerations" section. - - If no authentication is to be performed, then the simple - authentication option MUST be chosen, and the password be of zero - length. (This is often done by LDAPv2 clients.) Typically the DN is - also of zero length. - - The sasl choice allows for any mechanism defined for use with SASL - [12]. The mechanism field contains the name of the mechanism. The - credentials field contains the arbitrary data used for - authentication, inside an OCTET STRING wrapper. Note that unlike - some Internet application protocols where SASL is used, LDAP is not - text-based, thus no base64 transformations are performed on the - credentials. - - If any SASL-based integrity or confidentiality services are enabled, - they take effect following the transmission by the server and - reception by the client of the final BindResponse with resultCode - success. - - The client can request that the server use authentication information - from a lower layer protocol by using the SASL EXTERNAL mechanism. - - - - - -Wahl, et. al. Standards Track [Page 22] - -RFC 2251 LDAPv3 December 1997 - - -4.2.3. Bind Response - - 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 he - status of the client's request for authentication. - - f the bind was successful, the resultCode will be success, therwise - it will be one of: - - - operationsError: server encountered an internal error, - - - protocolError: unrecognized version number or incorrect PDU - structure, - - - authMethodNotSupported: unrecognized SASL mechanism name, - - - strongAuthRequired: the server requires authentication be - performed with a SASL mechanism, - - - referral: this server cannot accept this bind and the client - should try another, - - - saslBindInProgress: the server requires the client to send a - new bind request, with the same sasl mechanism, to continue the - authentication process, - - - inappropriateAuthentication: the server requires the client - which had attempted to bind anonymously or without supplying - credentials to provide some form of credentials, - - - invalidCredentials: the wrong password was supplied or the SASL - credentials could not be processed, - - - unavailable: the server is shutting down. - - If the server does not support the client's requested protocol - version, it MUST set the resultCode to protocolError. - - If the client receives a BindResponse response where the resultCode - was 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.) - - - -Wahl, et. al. Standards Track [Page 23] - -RFC 2251 LDAPv3 December 1997 - - - 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 password choice, or the SASL mechanism does - not require the server to return information to the client, then this - field is not to be included in the result. - -4.3. Unbind Operation - - The function of the Unbind Operation is to terminate a protocol - session. The Unbind Operation is defined as follows: - - UnbindRequest ::= [APPLICATION 2] NULL - - The Unbind Operation has no response defined. Upon transmission of an - UnbindRequest, a protocol client may assume that the protocol session - is terminated. Upon receipt of an UnbindRequest, a protocol server - may assume that the requesting client has terminated the session and - that all outstanding requests may be discarded, and may close the - connection. - -4.4. Unsolicited Notification - - 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 0 and protocolOp is of the extendedResp form. The - responseName field of the ExtendedResponse is present. The LDAPOID - value MUST be unique for this notification, and not be used in any - other situation. - - One unsolicited notification is defined in this document. - -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 - distinguishing between an error condition and a transient network - - - - - -Wahl, et. al. Standards Track [Page 24] - -RFC 2251 LDAPv3 December 1997 - - - 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. - - 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 resultCode values are to be 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 - underlying security association protecting communication between - the client and server has unexpectedly failed or been compromised. - - - unavailable: This server will stop accepting new connections and - operations on all existing connections, and be unavailable for an - extended period of time. The client may make use of an alternative - server. - - After sending this notice, the server MUST close the connection. - After receiving this notice, the client MUST NOT transmit any further - on the connection, and may abruptly close the connection. - -4.5. Search Operation - - The Search Operation allows a client to request that a search be - performed on its behalf by a server. This can be used to read - attributes from a single entry, from entries immediately below a - particular entry, or a whole subtree of entries. - -4.5.1. Search Request - - The Search Request is defined as follows: - - SearchRequest ::= [APPLICATION 3] SEQUENCE { - baseObject LDAPDN, - scope ENUMERATED { - baseObject (0), - singleLevel (1), - wholeSubtree (2) }, - derefAliases ENUMERATED { - neverDerefAliases (0), - derefInSearching (1), - derefFindingBaseObj (2), - - - -Wahl, et. al. Standards Track [Page 25] - -RFC 2251 LDAPv3 December 1997 - - - derefAlways (3) }, - sizeLimit INTEGER (0 .. maxInt), - timeLimit INTEGER (0 .. maxInt), - typesOnly BOOLEAN, - filter Filter, - attributes AttributeDescriptionList } - - Filter ::= CHOICE { - and [0] SET OF Filter, - or [1] SET OF Filter, - not [2] Filter, - equalityMatch [3] AttributeValueAssertion, - substrings [4] SubstringFilter, - greaterOrEqual [5] AttributeValueAssertion, - lessOrEqual [6] AttributeValueAssertion, - present [7] AttributeDescription, - approxMatch [8] AttributeValueAssertion, - extensibleMatch [9] MatchingRuleAssertion } - - SubstringFilter ::= SEQUENCE { - type AttributeDescription, - -- at least one must be present - substrings SEQUENCE OF CHOICE { - initial [0] LDAPString, - any [1] LDAPString, - final [2] LDAPString } } - - MatchingRuleAssertion ::= SEQUENCE { - matchingRule [1] MatchingRuleId OPTIONAL, - type [2] AttributeDescription OPTIONAL, - matchValue [3] AssertionValue, - dnAttributes [4] BOOLEAN DEFAULT FALSE } - - Parameters of the Search Request are: - - - baseObject: An LDAPDN that is the base object entry relative to - which the search is to be performed. - - - scope: An indicator of the scope of the search to be performed. The - semantics of the possible values of this field are identical to the - semantics of the scope field in the X.511 Search Operation. - - - derefAliases: An indicator as to how alias objects (as defined in - X.501) 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; - - - -Wahl, et. al. Standards Track [Page 26] - -RFC 2251 LDAPv3 December 1997 - - - derefInSearching: dereference aliases in subordinates of - the base object in searching, but not in locating the - base object of the search; - - 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. - - - sizelimit: A sizelimit that restricts the maximum number of entries - to be returned as a result of the search. A value of 0 in this - field indicates that no client-requested sizelimit restrictions are - in effect for the search. Servers may enforce a maximum number of - entries to return. - - - timelimit: A timelimit that restricts the maximum time (in seconds) - allowed for a search. A value of 0 in this field indicates that no - client-requested timelimit restrictions are in effect for the - search. - - - typesOnly: An indicator as to whether search results will contain - both attribute types and values, or just attribute types. Setting - this field to TRUE causes only attribute types (no values) to be - returned. Setting this field to FALSE causes both attribute types - 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. - - The 'and', 'or' and 'not' choices can be used to form combinations of - filters. At least one filter element MUST be present in an 'and' or - 'or' choice. The others match against individual attribute values of - entries in the scope of the search. (Implementor's note: the 'not' - filter is an example of a tagged choice in an implicitly-tagged - module. In BER this is treated as if the tag was explicit.) - - A server MUST evaluate filters according to the three-valued logic - of X.511(93) section 7.8.1. In summary, a filter is evaluated to - either "TRUE", "FALSE" or "Undefined". If the filter evaluates - to TRUE for a particular entry, then the attributes of that entry - are returned as part of the search result (subject to any applicable - access control restrictions). If the filter evaluates to FALSE or - Undefined, then the entry is ignored for the search. - - - - - - -Wahl, et. al. Standards Track [Page 27] - -RFC 2251 LDAPv3 December 1997 - - - A filter of the "and" choice is TRUE if all the filters in the SET - OF evaluate to TRUE, FALSE if at least one filter is FALSE, and - otherwise Undefined. A filter of the "or" choice is FALSE if all - of the filters in the SET OF evaluate to FALSE, TRUE if at least - one filter is TRUE, and Undefined otherwise. A filter of the "not" - choice is TRUE if the filter being negated is FALSE, FALSE if it is - TRUE, and Undefined if it is Undefined. - - The present match evaluates to TRUE where there is an attribute or - subtype of the specified attribute description present in an entry, - and FALSE otherwise (including a presence test with an unrecognized - attribute description.) - - The extensibleMatch is new in this version of LDAP. If the - matchingRule field is absent, the type field MUST be present, and - the equality match is performed for that type. If the type field is - absent and matchingRule is present, the matchValue is compared - against all attributes in an entry which support that matchingRule, - and 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 cannot be parsed.) If the type field is - present and matchingRule is present, the matchingRule MUST be one - permitted for use with that type, otherwise the filter item is - undefined. If the dnAttributes field is set to TRUE, the match is - applied against all the attributes in an entry's distinguished name - as well, and also evaluates to TRUE if there is at least one - attribute in the distinguished name for which the filter item - evaluates to TRUE. (Editors note: The dnAttributes field is present - so that there does not need to be multiple versions of generic - matching rules such as for word matching, one to apply to entries - and another to apply 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 cannot be parsed, or the type of filtering requested is not - implemented, then the filter is Undefined. Thus for example if a - server did not recognize the attribute type shoeSize, a filter of - (shoeSize=*) would evaluate to FALSE, and the filters (shoeSize=12), - (shoeSize>=12) and (shoeSize<=12) would evaluate to Undefined. - - - - - - -Wahl, et. al. Standards Track [Page 28] - -RFC 2251 LDAPv3 December 1997 - - - Servers MUST NOT return errors if attribute descriptions or matching - rule ids are not recognized, or assertion values cannot be parsed. - More details of filter processing are given in section 7.8 of X.511 - [8]. - - - attributes: A list of the attributes to be returned from each entry - which matches the search filter. 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 specific operational - attributes). - - Attributes MUST be named at most once in the list, and are 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. - - 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 arbitrarily and does not correspond to any attribute in use. - - Client implementors should note that even if all user attributes are - requested, some attributes of the entry may not be included in - search results due to access control or other restrictions. - Furthermore, servers will not return operational attributes, such - as objectClasses or attributeTypes, unless they are listed by name, - since there may be extremely large number of values for certain - operational attributes. (A list of operational attributes for use - in LDAP is given in [5].) - - 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 existence 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 must provide the same semantics - as the X.500 search operation. - -4.5.2. Search Result - - The results of the search attempted by the server upon receipt of a - Search Request are returned in Search Responses, which are LDAP - messages containing either SearchResultEntry, SearchResultReference, - ExtendedResponse or SearchResultDone data types. - - SearchResultEntry ::= [APPLICATION 4] SEQUENCE { - objectName LDAPDN, - - - -Wahl, et. al. Standards Track [Page 29] - -RFC 2251 LDAPv3 December 1997 - - - attributes PartialAttributeList } - - PartialAttributeList ::= SEQUENCE OF SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - -- implementors should note that the PartialAttributeList may - -- have zero elements (if none of the attributes of that entry - -- were requested, or could be returned), and that the vals set - -- may also have zero elements (if types only was requested, or - -- all values were excluded from the result.) - - SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL - -- at least one LDAPURL element must be present - - SearchResultDone ::= [APPLICATION 5] LDAPResult - - Upon receipt of a Search Request, a server will perform the necessary - search of the DIT. - - If the LDAP session is operating over a connection-oriented transport - such as TCP, the server will return to the client a sequence of - responses in separate LDAP messages. There may be zero or more - responses containing SearchResultEntry, one for each entry found - during the search. There may also be zero or more responses - containing SearchResultReference, one for each area not explored by - this server during the search. The SearchResultEntry and - SearchResultReference PDUs may come in any order. Following all the - SearchResultReference responses and all SearchResultEntry responses - to be returned by the server, the server will return a response - containing the SearchResultDone, which contains an indication of - success, or detailing any errors that have occurred. - - Each entry returned in a SearchResultEntry will contain all - attributes, complete with associated values if necessary, as - specified in the attributes field of the Search Request. Return of - attributes is subject to access control and other administrative - policy. Some attributes may be returned in binary format (indicated - by the AttributeDescription in the response having the binary option - present). - - Some attributes may be constructed by the server and appear in a - SearchResultEntry attribute list, although they are not stored - attributes of an entry. Clients MUST NOT assume that all attributes - can be modified, even if permitted by access control. - - LDAPMessage responses of the ExtendedResponse form are reserved for - returning information associated with a control requested by the - client. These may be defined in future versions of this document. - - - -Wahl, et. al. Standards Track [Page 30] - -RFC 2251 LDAPv3 December 1997 - - -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 under the baseObject, the server may return one or more - SearchResultReference, 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 resultCode. - - In the absence of indexing information provided to a server from - servers holding subordinate naming contexts, SearchResultReference - responses are not affected by search filters and are always returned - when in scope. - - The SearchResultReference is of the same data type as the Referral. - URLs for servers implementing the LDAP protocol are written according - to [9]. The <dn> part MUST be present in the URL, with the new target - object name. The client MUST use this name in its next request. - Some servers (e.g. part of a distributed index exchange system) may - provide a different filter in the URLs of the SearchResultReference. - If the filter part of the URL is present in an LDAP URL, the client - MUST use the new filter in its next request to progress the search, - and if the filter part is absent the client will use again the same - filter. Other aspects of the new search request may be the same or - different as the search which generated the continuation references. - - Other kinds of URLs may be returned so long as the operation could be - performed using that protocol. - - The name of an unexplored subtree in a SearchResultReference need not - be subordinate to the base object. - - In order to complete the search, the client MUST issue 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 a connection between a client and server, - and if the client has multiple outstanding search operations to - different servers, it MUST abandon each operation individually. - -4.5.3.1. Example - - For example, suppose the contacted server (hosta) holds the entry - "O=MNN,C=WW" and the entry "CN=Manager,O=MNN,C=WW". It knows that - either LDAP-capable servers (hostb) or (hostc) hold - "OU=People,O=MNN,C=WW" (one is the master and the other server a - - - - -Wahl, et. al. Standards Track [Page 31] - -RFC 2251 LDAPv3 December 1997 - - - shadow), and that LDAP-capable server (hostd) holds the subtree - "OU=Roles,O=MNN,C=WW". If a subtree search of "O=MNN,C=WW" is - requested to the contacted server, it may return the following: - - SearchResultEntry for O=MNN,C=WW - SearchResultEntry for CN=Manager,O=MNN,C=WW - SearchResultReference { - ldap://hostb/OU=People,O=MNN,C=WW - ldap://hostc/OU=People,O=MNN,C=WW - } - SearchResultReference { - ldap://hostd/OU=Roles,O=MNN,C=WW - } - 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,O=MNN,C=WW", the server might respond as follows: - - SearchResultEntry for OU=People,O=MNN,C=WW - SearchResultReference { - ldap://hoste/OU=Managers,OU=People,O=MNN,C=WW - } - SearchResultReference { - ldap://hostf/OU=Consultants,OU=People,O=MNN,C=WW - } - 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 "O=XYZ,C=US" to hosta, the server - may return only a SearchResultDone containing a referral. - - SearchResultDone (referral) { - ldap://hostg/ - } - -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, - modification SEQUENCE OF SEQUENCE { - - - -Wahl, et. al. Standards Track [Page 32] - -RFC 2251 LDAPv3 December 1997 - - - operation ENUMERATED { - add (0), - delete (1), - replace (2) }, - modification AttributeTypeAndValues } } - - AttributeTypeAndValues ::= SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - Parameters of the Modify Request are: - - - object: The object to be modified. The value of this field contains - the DN of the entry to be modified. The server will not perform - any alias dereferencing in determining the object to be modified. - - - modification: A list of modifications to be performed on the entry. - The entire list of entry modifications MUST be performed - in the order they are listed, as a single atomic operation. While - individual modifications may violate the directory schema, the - resulting entry after the entire list of modifications is performed - MUST conform to the requirements of the directory schema. The - values that may be taken on by the 'operation' field in each - modification construct have the following semantics respectively: - - add: add values listed to the given attribute, creating - the attribute if necessary; - - delete: delete values listed from the given 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 given 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. - - The result of the modify attempted by the server upon receipt of a - Modify Request is returned in a Modify Response, defined as follows: - - ModifyResponse ::= [APPLICATION 7] LDAPResult - - Upon receipt of a Modify Request, a server will perform the necessary - modifications to the DIT. - - - - - -Wahl, et. al. Standards Track [Page 33] - -RFC 2251 LDAPv3 December 1997 - - - 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 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, those values which form the entry's - relative distinguished name. An attempt to do so will result in the - server returning the error notAllowedOnRDN. The Modify DN Operation - described in section 4.9 is used to rename an entry. - - If an equality match filter has not been defined for an attribute type, - clients MUST NOT attempt to delete individual values of that attribute - from an entry using the "delete" form of a modification, and MUST - instead use the "replace" form. - - Note that due to the simplifications made in LDAP, there is not a - direct mapping of the modifications in an LDAP ModifyRequest onto the - EntryModifications of a DAP ModifyEntry operation, and different - implementations of LDAP-DAP gateways may use different means of - representing the 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 SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - Parameters of the Add Request are: - - - entry: the Distinguished Name of the entry to be added. Note that - the server will not dereference any aliases in locating the entry - to be added. - - - - -Wahl, et. al. Standards Track [Page 34] - -RFC 2251 LDAPv3 December 1997 - - - - 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 the createTimestamp or - creatorsName attributes, since these will be generated - automatically by the server. - - The entry named in the entry field of the AddRequest MUST NOT exist - for the AddRequest to succeed. The parent of the entry to be added - MUST exist. For example, if the client attempted to add - "CN=JS,O=Foo,C=US", the "O=Foo,C=US" entry did not exist, and the - "C=US" entry did exist, then the server would return the error - noSuchObject with the matchedDN field containing "C=US". 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. - - Servers implementations SHOULD NOT restrict where entries can be - located in the directory. Some servers MAY 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 perform the - add requested. 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. - -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 Distinguished Name of the entry to - be deleted. Note that the server will not dereference aliases while - resolving the name of the target entry to be removed, and that only - leaf entries (those with no subordinate entries) can be deleted with - this operation. - - The result of the delete attempted by the server upon receipt of a - Delete Request is returned in the Delete Response, defined as - follows: - - - -Wahl, et. al. Standards Track [Page 35] - -RFC 2251 LDAPv3 December 1997 - - - DelResponse ::= [APPLICATION 11] LDAPResult - - Upon receipt of a Delete Request, a server will attempt to perform - the entry removal requested. The result of the delete attempt will be - returned to the client in the Delete Response. - -4.9. Modify DN Operation - - The Modify DN Operation allows a client to change the leftmost (least - significant) component of the name of an entry in the directory, 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: - - - entry: the Distinguished Name of the entry to be changed. This - entry may or may not have subordinate entries. - - - newrdn: the RDN that will form the leftmost component of the new - name 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. - - - newSuperior: if present, this is the Distinguished Name of the entry - which becomes the immediate superior of the existing entry. - - The result of the name change attempted by the server upon receipt of - a Modify DN Request is returned in the Modify DN Response, defined - as follows: - - ModifyDNResponse ::= [APPLICATION 13] LDAPResult - - Upon receipt of a ModifyDNRequest, a server will attempt to - perform the name change. The result of the name change attempt will - be returned to the client in the Modify DN Response. - - 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 - - - - -Wahl, et. al. Standards Track [Page 36] - -RFC 2251 LDAPv3 December 1997 - - - attempt to rename the entry to be "cn=John Cougar Smith,c=US". If - there was already an entry with that name, the operation would fail - with error code entryAlreadyExists. - - 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 may - not perform the operation and return an error code if the setting of - the deleteoldrdn parameter 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 - resultCode affectsMultipleDSAs 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. - -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: - - CompareRequest ::= [APPLICATION 14] SEQUENCE { - entry LDAPDN, - ava AttributeValueAssertion } - - Parameters of the Compare Request are: - - - entry: the name of the entry to be compared with. - - - ava: the assertion with which an attribute in the entry is to be - compared. - - The result of the compare attempted by the server upon receipt of a - Compare Request is returned in the Compare Response, defined as - follows: - - CompareResponse ::= [APPLICATION 15] LDAPResult - - Upon receipt of a Compare Request, a server will attempt to perform - the requested comparison. The result of the comparison will be - returned to the client in the Compare Response. Note that errors and - the result of comparison are all returned in the same construct. - - - - - -Wahl, et. al. Standards Track [Page 37] - -RFC 2251 LDAPv3 December 1997 - - - Note that some directory systems may establish access controls which - permit the values of certain attributes (such as userPassword) to be - compared but not read. In a search result, it may be that an - attribute of that type would be returned, but with an empty set of - values. - -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 a an operation which was requested - earlier in this connection. - - (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 - transmission of an Abandon Operation, a client may expect that the - operation identified by the Message ID in the Abandon Request has - been abandoned. In the event that a server receives an Abandon - Request on a Search Operation in the midst of transmitting responses - to the search, that 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 - 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). - - 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 - - An extension mechanism has been added in this version of LDAP, in - order to allow additional operations to be defined for services not - available elsewhere in this protocol, for instance digitally signed - operations and results. - - - - - - -Wahl, et. al. Standards Track [Page 38] - -RFC 2251 LDAPv3 December 1997 - - - 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 - request MUST have a unique OBJECT IDENTIFIER assigned to it. - - ExtendedRequest ::= [APPLICATION 23] SEQUENCE { - requestName [0] LDAPOID, - requestValue [1] OCTET STRING OPTIONAL } - - The requestName is a dotted-decimal representation of the 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 - ExtendedResponse. - - ExtendedResponse ::= [APPLICATION 24] SEQUENCE { - COMPONENTS OF LDAPResult, - responseName [10] LDAPOID OPTIONAL, - response [11] OCTET STRING OPTIONAL } - - If the server does not recognize the request name, it MUST return - only the response fields from LDAPResult, containing the - protocolError result code. - -5. Protocol Element Encodings and Transfer - - One underlying service is defined here. Clients and servers SHOULD - implement the mapping of LDAP over TCP described in 5.2.1. - -5.1. Mapping Onto BER-based Transport Services - - The protocol elements of LDAP are encoded for exchange using the - Basic Encoding Rules (BER) [11] of ASN.1 [3]. However, due to the - high overhead involved in using certain elements of the BER, the - following additional restrictions are placed on BER-encodings of LDAP - protocol elements: - - (1) Only the definite form of length encoding will be used. - - (2) OCTET STRING values will be encoded in the primitive form only. - - (3) If the value of a BOOLEAN type is true, the encoding MUST have - its contents octets set to hex "FF". - - - - - - -Wahl, et. al. Standards Track [Page 39] - -RFC 2251 LDAPv3 December 1997 - - - (4) If a value of a type is its default value, it MUST be absent. - Only some BOOLEAN and INTEGER types have default values in this - protocol definition. - - These restrictions do not apply to ASN.1 types encapsulated inside of - OCTET STRING values, such as attribute values, unless otherwise - noted. - -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. - -5.2.1. Transmission Control Protocol (TCP) - - The LDAPMessage PDUs are mapped directly onto the TCP bytestream. It - is recommended that server implementations running over the TCP MAY - provide a protocol listener on the assigned port, 389. Servers may - instead provide a listener on a different port number. Clients MUST - support contacting servers on any valid TCP port. - -6. Implementation Guidelines - - This document describes an Internet protocol. - -6.1. Server Implementations - - The server MUST be capable of recognizing all the mandatory attribute - type names and implement the syntaxes specified in [5]. Servers MAY - also recognize additional attribute type names. - -6.2. Client Implementations - - Clients which request 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 may be using a counter that is incremented each time - referral handling occurs for an operation, and these kinds of clients - MUST be able to handle a DIT with at least ten layers of naming - contexts between the root and a leaf entry. - - In the absence of prior agreements with servers, clients SHOULD NOT - assume that servers support any particular schemas beyond those - referenced in section 6.1. Different schemas can have different - attribute types with the same names. The client can retrieve the - subschema entries referenced by the subschemaSubentry attribute in - the server's root DSE or in entries held by the server. - - - -Wahl, et. al. Standards Track [Page 40] - -RFC 2251 LDAPv3 December 1997 - - -7. Security Considerations - - When used with a connection-oriented transport, this version of the - protocol provides facilities for the LDAP v2 authentication - mechanism, simple authentication using a cleartext password, as well - as any SASL mechanism [12]. 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. - - When used with SASL, it should be noted that the name field of the - BindRequest is not protected against modification. Thus if the - distinguished name of the client (an LDAPDN) is agreed through the - negotiation of the credentials, it takes precedence over any value in - the unprotected name field. - - 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 cache. - -8. Acknowledgements - - This document is an update to RFC 1777, by Wengyik Yeong, Tim Howes, - and Steve Kille. Design ideas included in this document are based on - those discussed in ASID and other IETF Working Groups. The - contributions of individuals in these working groups is gratefully - acknowledged. - -9. Bibliography - - [1] ITU-T Rec. X.500, "The Directory: Overview of Concepts, Models - and Service", 1993. - - [2] Yeong, W., Howes, T., and S. Kille, "Lightweight Directory Access - Protocol", RFC 1777, March 1995. - - [3] ITU-T Rec. X.680, "Abstract Syntax Notation One (ASN.1) - - Specification of Basic Notation", 1994. - - - - -Wahl, et. al. Standards Track [Page 41] - -RFC 2251 LDAPv3 December 1997 - - - [4] Kille, S., Wahl, M., and T. Howes, "Lightweight Directory Access - Protocol (v3): UTF-8 String Representation of Distinguished - Names", RFC 2253, December 1997. - - [5] Wahl, M., Coulbeck, A., Howes, T., and S. Kille, "Lightweight - Directory Access Protocol (v3): Attribute Syntax Definitions", - RFC 2252, December 1997. - - [6] ITU-T Rec. X.501, "The Directory: Models", 1993. - - [7] Berners-Lee, T., Masinter, L., and M. McCahill, "Uniform - Resource Locators (URL)", RFC 1738, December 1994. - - [8] ITU-T Rec. X.511, "The Directory: Abstract Service Definition", - 1993. - - [9] Howes, T., and M. Smith, "The LDAP URL Format", RFC 2255, - December 1997. - - [10] Bradner, S., "Key words for use in RFCs to Indicate Requirement - Levels", RFC 2119, March 1997. - - [11] ITU-T Rec. X.690, "Specification of ASN.1 encoding rules: Basic, - Canonical, and Distinguished Encoding Rules", 1994. - - [12] Meyers, J., "Simple Authentication and Security Layer", - RFC 2222, October 1997. - - [13] Universal Multiple-Octet Coded Character Set (UCS) - - Architecture and Basic Multilingual Plane, ISO/IEC 10646-1 : - 1993. - - [14] Yergeau, F., "UTF-8, a transformation format of Unicode and ISO - 10646", RFC 2044, October 1996. - -10. Authors' Addresses - - Mark Wahl - Critical Angle Inc. - 4815 W Braker Lane #502-385 - Austin, TX 78759 - USA - - Phone: +1 512 372-3160 - EMail: M.Wahl@critical-angle.com - - - - - - -Wahl, et. al. Standards Track [Page 42] - -RFC 2251 LDAPv3 December 1997 - - - Tim Howes - Netscape Communications Corp. - 501 E. Middlefield Rd., MS MV068 - Mountain View, CA 94043 - USA - - Phone: +1 650 937-3419 - EMail: howes@netscape.com - - Steve Kille - Isode Limited - The Dome, The Square - Richmond - TW9 1DT - UK - - Phone: +44-181-332-9091 - EMail: S.Kille@isode.com - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Wahl, et. al. Standards Track [Page 43] - -RFC 2251 LDAPv3 December 1997 - - -Appendix A - Complete ASN.1 Definition - - Lightweight-Directory-Access-Protocol-V3 DEFINITIONS - IMPLICIT TAGS ::= - - BEGIN - - LDAPMessage ::= SEQUENCE { - messageID MessageID, - protocolOp CHOICE { - bindRequest BindRequest, - bindResponse BindResponse, - unbindRequest UnbindRequest, - searchRequest SearchRequest, - searchResEntry SearchResultEntry, - searchResDone SearchResultDone, - searchResRef SearchResultReference, - modifyRequest ModifyRequest, - modifyResponse ModifyResponse, - addRequest AddRequest, - addResponse AddResponse, - delRequest DelRequest, - delResponse DelResponse, - modDNRequest ModifyDNRequest, - modDNResponse ModifyDNResponse, - compareRequest CompareRequest, - compareResponse CompareResponse, - abandonRequest AbandonRequest, - extendedReq ExtendedRequest, - extendedResp ExtendedResponse }, - controls [0] Controls OPTIONAL } - - MessageID ::= INTEGER (0 .. maxInt) - - maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- - - LDAPString ::= OCTET STRING - - LDAPOID ::= OCTET STRING - - LDAPDN ::= LDAPString - - RelativeLDAPDN ::= LDAPString - - AttributeType ::= LDAPString - - AttributeDescription ::= LDAPString - - - - -Wahl, et. al. Standards Track [Page 44] - -RFC 2251 LDAPv3 December 1997 - - - AttributeDescriptionList ::= SEQUENCE OF - AttributeDescription - - AttributeValue ::= OCTET STRING - - AttributeValueAssertion ::= SEQUENCE { - attributeDesc AttributeDescription, - assertionValue AssertionValue } - - AssertionValue ::= OCTET STRING - - Attribute ::= SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - MatchingRuleId ::= LDAPString - - LDAPResult ::= SEQUENCE { - resultCode ENUMERATED { - success (0), - operationsError (1), - protocolError (2), - timeLimitExceeded (3), - sizeLimitExceeded (4), - compareFalse (5), - compareTrue (6), - authMethodNotSupported (7), - strongAuthRequired (8), - -- 9 reserved -- - referral (10), -- new - adminLimitExceeded (11), -- new - unavailableCriticalExtension (12), -- new - confidentialityRequired (13), -- new - saslBindInProgress (14), -- new - noSuchAttribute (16), - undefinedAttributeType (17), - inappropriateMatching (18), - constraintViolation (19), - 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), - - - -Wahl, et. al. Standards Track [Page 45] - -RFC 2251 LDAPv3 December 1997 - - - 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), -- new - -- 72-79 unused -- - other (80) }, - -- 81-90 reserved for APIs -- - matchedDN LDAPDN, - errorMessage LDAPString, - referral [3] Referral OPTIONAL } - - Referral ::= SEQUENCE OF LDAPURL - - LDAPURL ::= LDAPString -- limited to characters permitted in URLs - - Controls ::= SEQUENCE OF Control - - Control ::= SEQUENCE { - controlType LDAPOID, - criticality BOOLEAN DEFAULT FALSE, - controlValue OCTET STRING OPTIONAL } - - 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 } - - BindResponse ::= [APPLICATION 1] SEQUENCE { - - - -Wahl, et. al. Standards Track [Page 46] - -RFC 2251 LDAPv3 December 1997 - - - COMPONENTS OF LDAPResult, - serverSaslCreds [7] OCTET STRING OPTIONAL } - - UnbindRequest ::= [APPLICATION 2] NULL - - 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 AttributeDescriptionList } - - Filter ::= CHOICE { - and [0] SET OF Filter, - or [1] SET OF Filter, - not [2] Filter, - equalityMatch [3] AttributeValueAssertion, - substrings [4] SubstringFilter, - greaterOrEqual [5] AttributeValueAssertion, - lessOrEqual [6] AttributeValueAssertion, - present [7] AttributeDescription, - approxMatch [8] AttributeValueAssertion, - extensibleMatch [9] MatchingRuleAssertion } - - SubstringFilter ::= SEQUENCE { - type AttributeDescription, - -- at least one must be present - substrings SEQUENCE OF CHOICE { - initial [0] LDAPString, - any [1] LDAPString, - final [2] LDAPString } } - - MatchingRuleAssertion ::= SEQUENCE { - matchingRule [1] MatchingRuleId OPTIONAL, - type [2] AttributeDescription OPTIONAL, - matchValue [3] AssertionValue, - dnAttributes [4] BOOLEAN DEFAULT FALSE } - - - - -Wahl, et. al. Standards Track [Page 47] - -RFC 2251 LDAPv3 December 1997 - - - SearchResultEntry ::= [APPLICATION 4] SEQUENCE { - objectName LDAPDN, - attributes PartialAttributeList } - - PartialAttributeList ::= SEQUENCE OF SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL - - SearchResultDone ::= [APPLICATION 5] LDAPResult - - ModifyRequest ::= [APPLICATION 6] SEQUENCE { - object LDAPDN, - modification SEQUENCE OF SEQUENCE { - operation ENUMERATED { - add (0), - delete (1), - replace (2) }, - modification AttributeTypeAndValues } } - - AttributeTypeAndValues ::= SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - ModifyResponse ::= [APPLICATION 7] LDAPResult - - AddRequest ::= [APPLICATION 8] SEQUENCE { - entry LDAPDN, - attributes AttributeList } - - AttributeList ::= SEQUENCE OF SEQUENCE { - type AttributeDescription, - vals SET OF AttributeValue } - - AddResponse ::= [APPLICATION 9] LDAPResult - - DelRequest ::= [APPLICATION 10] LDAPDN - - DelResponse ::= [APPLICATION 11] LDAPResult - - ModifyDNRequest ::= [APPLICATION 12] SEQUENCE { - entry LDAPDN, - newrdn RelativeLDAPDN, - deleteoldrdn BOOLEAN, - newSuperior [0] LDAPDN OPTIONAL } - - ModifyDNResponse ::= [APPLICATION 13] LDAPResult - - - -Wahl, et. al. Standards Track [Page 48] - -RFC 2251 LDAPv3 December 1997 - - - CompareRequest ::= [APPLICATION 14] SEQUENCE { - entry LDAPDN, - ava AttributeValueAssertion } - - CompareResponse ::= [APPLICATION 15] LDAPResult - - AbandonRequest ::= [APPLICATION 16] MessageID - - ExtendedRequest ::= [APPLICATION 23] SEQUENCE { - requestName [0] LDAPOID, - requestValue [1] OCTET STRING OPTIONAL } - - ExtendedResponse ::= [APPLICATION 24] SEQUENCE { - COMPONENTS OF LDAPResult, - responseName [10] LDAPOID OPTIONAL, - response [11] OCTET STRING OPTIONAL } - - END - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Wahl, et. al. Standards Track [Page 49] - -RFC 2251 LDAPv3 December 1997 - - -Full Copyright Statement - - Copyright (C) The Internet Society (1997). All Rights Reserved. - - This document and translations of it may be copied and furnished to - others, and derivative works that comment on or otherwise explain it - or assist in its implementation may be prepared, copied, published - and distributed, in whole or in part, without restriction of any - kind, provided that the above copyright notice and this paragraph are - included on all such copies and derivative works. However, this - document itself may not be modified in any way, such as by removing - the copyright notice or references to the Internet Society or other - Internet organizations, except as needed for the purpose of - developing Internet standards in which case the procedures for - copyrights defined in the Internet Standards process must be - followed, or as required to translate it into languages other than - English. - - The limited permissions granted above are perpetual and will not be - revoked by the Internet Society or its successors or assigns. - - This document and the information contained herein is provided on an - "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING - TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING - BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION - HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF - MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. - - - - - - - - - - - - - - - - - - - - - - - - -Wahl, et. al. 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