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'Roadmap' -- No information found for draft-ietf-ldapbis-xx - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'LDAPIANA' -- Possible downref: Non-RFC (?) normative reference: ref. 'ISO10646' ** Obsolete normative reference: RFC 2279 (Obsoleted by RFC 3629) -- No information found for draft-ietf-ldapbis-models-xx - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'Models' -- No information found for draft-ietf-ldapbis-dn-xx - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'LDAPDN' -- No information found for draft-ietf-ldapbis-syntaxes-xx - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'Syntaxes' ** Obsolete normative reference: RFC 2396 (Obsoleted by RFC 3986) -- No information found for draft-ietf-ldapbis-authmeth-xx - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'AuthMeth' ** Obsolete normative reference: RFC 2222 (Obsoleted by RFC 4422, RFC 4752) -- No information found for draft-ietf-sasl-saslprep-xx - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'SASLPrep' -- Possible downref: Non-RFC (?) normative reference: ref. 'Unicode' Summary: 8 errors (**), 0 flaws (~~), 32 warnings (==), 30 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Internet-Draft Editor: J. Sermersheim 3 Intended Category: Standard Track Novell, Inc 4 Document: draft-ietf-ldapbis-protocol-14.txt Jun 2003 5 Obsoletes: RFC 2251 7 LDAP: The Protocol 9 Status of this Memo 11 This document is an Internet-Draft and is in full conformance with 12 all provisions of Section 10 of RFC2026. 14 Internet-Drafts are working documents of the Internet Engineering 15 Task Force (IETF), its areas, and its working groups. Note that other 16 groups may also distribute working documents as Internet-Drafts. 17 Internet-Drafts are draft documents valid for a maximum of six months 18 and may be updated, replaced, or obsoleted by other documents at any 19 time. It is inappropriate to use Internet-Drafts as reference 20 material or to cite them other than as "work in progress." 22 The list of current Internet-Drafts can be accessed at 23 http://www.ietf.org/ietf/1id-abstracts.txt 25 The list of Internet-Draft Shadow Directories can be accessed at 26 http://www.ietf.org/shadow.html. 28 Distribution of this memo is unlimited. Technical discussion of this 29 document will take place on the IETF LDAP Revision Working Group 30 (LDAPbis) mailing list . Please send 31 editorial comments directly to the editor . 33 Abstract 35 This document describes the protocol elements, along with their 36 semantics and encodings, for the Lightweight Directory Access 37 Protocol (LDAP). LDAP provides access to distributed directory 38 services that act in accordance with X.500 data and service models. 39 These protocol elements are based on those described in the X.500 40 Directory Access Protocol (DAP). 42 Table of Contents 44 1. Introduction.....................................................2 45 2. Conventions......................................................3 46 3. Protocol Model...................................................3 47 4. Elements of Protocol.............................................4 48 4.1. Common Elements................................................4 49 4.1.1. Message Envelope.............................................4 50 4.1.2. String Types.................................................6 51 4.1.3. Distinguished Name and Relative Distinguished Name...........6 52 Lightweight Directory Access Protocol Version 3 54 4.1.4. Attribute Descriptions.......................................6 55 4.1.5. Attribute Value..............................................7 56 4.1.6. Attribute Value Assertion....................................7 57 4.1.7. Attribute....................................................8 58 4.1.8. Matching Rule Identifier.....................................8 59 4.1.9. Result Message...............................................8 60 4.1.10. Referral...................................................10 61 4.1.11. Controls...................................................11 62 4.2. Bind Operation................................................12 63 4.3. Unbind Operation..............................................15 64 4.4. Unsolicited Notification......................................15 65 4.5. Search Operation..............................................16 66 4.6. Modify Operation..............................................23 67 4.7. Add Operation.................................................25 68 4.8. Delete Operation..............................................26 69 4.9. Modify DN Operation...........................................26 70 4.10. Compare Operation............................................27 71 4.11. Abandon Operation............................................28 72 4.12. Extended Operation...........................................29 73 4.13. Start TLS Operation..........................................29 74 5. Protocol Element Encodings and Transfer.........................31 75 5.1. Protocol Encoding.............................................31 76 5.2. Transfer Protocols............................................32 77 6. Implementation Guidelines.......................................32 78 6.1. Server Implementations........................................32 79 6.2. Client Implementations........................................32 80 7. Security Considerations.........................................33 81 8. Acknowledgements................................................33 82 9. Normative References............................................33 83 10. Editor's Address...............................................35 84 Appendix A - LDAP Result Codes.....................................36 85 A.1 Non-Error Result Codes.........................................36 86 A.2 Error Result Codes.............................................36 87 A.3 Classes and Precedence of Error Result Codes...................36 88 Appendix C - Change History........................................47 89 C.1 Changes made to RFC 2251:......................................47 90 C.2 Changes made to draft-ietf-ldapbis-protocol-00.txt:............47 91 C.3 Changes made to draft-ietf-ldapbis-protocol-01.txt:............48 92 C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt:............48 93 C.5 Changes made to draft-ietf-ldapbis-protocol-03.txt:............50 94 C.6 Changes made to draft-ietf-ldapbis-protocol-04.txt:............52 95 C.7 Changes made to draft-ietf-ldapbis-protocol-05.txt:............52 96 C.8 Changes made to draft-ietf-ldapbis-protocol-06.txt:............53 97 C.9 Changes made to draft-ietf-ldapbis-protocol-07.txt:............56 98 C.10 Changes made to draft-ietf-ldapbis-protocol-08.txt:...........56 99 C.11 Changes made to draft-ietf-ldapbis-protocol-09.txt:...........56 100 C.12 Changes made to draft-ietf-ldapbis-protocol-10.txt:...........56 101 C.13 Changes made to draft-ietf-ldapbis-protocol-11.txt:...........57 102 C.14 Changes made to draft-ietf-ldapbis-protocol-12.txt:...........57 103 C.15 Changes made to draft-ietf-ldapbis-protocol-13.txt............57 104 Appendix D - Outstanding Work Items................................58 106 1. Introduction 107 Lightweight Directory Access Protocol Version 3 109 The Directory is "a collection of open systems cooperating to provide 110 directory services" [X.500]. A Directory user, which may be a human 111 or other entity, accesses the Directory through a client (or 112 Directory User Agent (DUA)). The client, on behalf of the directory 113 user, interacts with one or more servers (or Directory System Agents 114 (DSA)). Clients interact with servers using a directory access 115 protocol. 117 This document details the protocol elements of Lightweight Directory 118 Access Protocol, along with their semantics. Following the 119 description of protocol elements, it describes the way in which the 120 protocol is encoded and transferred. 122 This document is an integral part of the LDAP Technical Specification 123 [Roadmap]. 125 This document replaces RFC 2251. Appendix C holds a detailed log of 126 changes to RFC 2251. Prior to Working Group Last Call, this appendix 127 will be distilled to a summary of changes to RFC 2251. 129 2. Conventions 131 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 132 "SHOULD", "SHOULD NOT", "RECOMMENDED", and "MAY" in this document are 133 to be interpreted as described in [RFC2119]. 134 The terms "connection" and "LDAP connection" both refer to the 135 underlying transport protocol connection between two protocol peers. 136 The term "TLS connection" refers to a TLS-protected LDAP connection. 137 The terms "association" and "LDAP association" both refer to the 138 association of the LDAP connection and the current authentication and 139 authorization state. 141 3. Protocol Model 143 The general model adopted by this protocol is one of clients 144 performing protocol operations against servers. In this model, a 145 client transmits a protocol request describing the operation to be 146 performed to a server. The server is then responsible for performing 147 the necessary operation(s) in the directory. Upon completion of the 148 operation(s), the server returns a response containing any results or 149 errors to the requesting client. 151 Note that although servers are required to return responses whenever 152 such responses are defined in the protocol, there is no requirement 153 for synchronous behavior on the part of either clients or servers. 154 Requests and responses for multiple operations may be exchanged 155 between a client and server in any order, provided the client 156 eventually receives a response for every request that requires one. 158 Note that the core protocol operations defined in this document can 159 be mapped to a subset of the X.500(1997) directory abstract service. 161 Lightweight Directory Access Protocol Version 3 163 However there is not a one-to-one mapping between LDAP protocol 164 operations and DAP operations. Server implementations acting as a 165 gateway to X.500 directories may need to make multiple DAP requests. 167 4. Elements of Protocol 169 The LDAP protocol is described using Abstract Syntax Notation 1 170 (ASN.1) [X.680], and is transferred using a subset of ASN.1 Basic 171 Encoding Rules [X.690]. Section 5.1 specifies how the protocol is 172 encoded and transferred. 174 In order to support future Standards Track extensions to this 175 protocol, extensibility is implied where it is allowed (per ASN.1). 176 In addition, ellipses (...) have been supplied in ASN.1 types that 177 are explicitly extensible as discussed in [LDAPIANA]. Because of the 178 implied extensibility, clients and servers MUST ignore trailing 179 SEQUENCE elements whose tags they do not recognize. 181 Changes to the LDAP protocol other than through the extension 182 mechanisms described here require a different version number. A 183 client indicates the version it is using as part of the bind request, 184 described in section 4.2. If a client has not sent a bind, the server 185 MUST assume the client is using version 3 or later. 187 Clients may determine the protocol versions a server supports by 188 reading the supportedLDAPVersion attribute from the root DSE 189 [Models]. Servers which implement version 3 or later MUST provide 190 this attribute. 192 4.1. Common Elements 194 This section describes the LDAPMessage envelope PDU (Protocol Data 195 Unit) format, as well as data type definitions, which are used in the 196 protocol operations. 198 4.1.1. Message Envelope 200 For the purposes of protocol exchanges, all protocol operations are 201 encapsulated in a common envelope, the LDAPMessage, which is defined 202 as follows: 204 LDAPMessage ::= SEQUENCE { 205 messageID MessageID, 206 protocolOp CHOICE { 207 bindRequest BindRequest, 208 bindResponse BindResponse, 209 unbindRequest UnbindRequest, 210 searchRequest SearchRequest, 211 searchResEntry SearchResultEntry, 212 searchResDone SearchResultDone, 213 searchResRef SearchResultReference, 214 Lightweight Directory Access Protocol Version 3 216 modifyRequest ModifyRequest, 217 modifyResponse ModifyResponse, 218 addRequest AddRequest, 219 addResponse AddResponse, 220 delRequest DelRequest, 221 delResponse DelResponse, 222 modDNRequest ModifyDNRequest, 223 modDNResponse ModifyDNResponse, 224 compareRequest CompareRequest, 225 compareResponse CompareResponse, 226 abandonRequest AbandonRequest, 227 extendedReq ExtendedRequest, 228 extendedResp ExtendedResponse, 229 ... }, 230 controls [0] Controls OPTIONAL } 232 MessageID ::= INTEGER (0 .. maxInt) 234 maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- 236 The function of the LDAPMessage is to provide an envelope containing 237 common fields required in all protocol exchanges. At this time the 238 only common fields are the message ID and the controls. 240 If the server receives a PDU from the client in which the LDAPMessage 241 SEQUENCE tag cannot be recognized, the messageID cannot be parsed, 242 the tag of the protocolOp is not recognized as a request, or the 243 encoding structures or lengths of data fields are found to be 244 incorrect, then the server MAY return the Notice of Disconnection 245 described in section 4.4.1, with resultCode protocolError, and MUST 246 immediately close the connection. 248 In other cases where the client or server cannot parse a PDU, it 249 SHOULD abruptly close the connection where further communication 250 (including providing notice) would be pernicious. Otherwise, server 251 implementations MUST return an appropriate response to the request, 252 with the resultCode set to protocolError. 254 The ASN.1 type Controls is defined in section 4.1.11. 256 4.1.1.1. Message ID 258 All LDAPMessage envelopes encapsulating responses contain the 259 messageID value of the corresponding request LDAPMessage. 261 The message ID of a request MUST have a non-zero value different from 262 the values of any other requests outstanding in the LDAP association 263 of which this message is a part. The zero value is reserved for the 264 unsolicited notification message. 266 Typical clients increment a counter for each request. 268 Lightweight Directory Access Protocol Version 3 270 A client MUST NOT send a request with the same message ID as an 271 earlier request on the same LDAP association unless it can be 272 determined that the server is no longer servicing the earlier 273 request. Otherwise the behavior is undefined. For operations that do 274 not return responses (unbind, abandon, and abandoned operations), the 275 client SHOULD assume the operation is in progress until a subsequent 276 bind request completes. 278 4.1.2. String Types 280 The LDAPString is a notational convenience to indicate that, although 281 strings of LDAPString type encode as OCTET STRING types, the 282 [ISO10646] character set (a superset of [Unicode]) is used, encoded 283 following the UTF-8 algorithm [RFC2279]. Note that in the UTF-8 284 algorithm characters which are the same as ASCII (0x0000 through 285 0x007F) are represented as that same ASCII character in a single 286 byte. The other byte values are used to form a variable-length 287 encoding of an arbitrary character. 289 LDAPString ::= OCTET STRING -- UTF-8 encoded, 290 -- ISO 10646 characters 292 The LDAPOID is a notational convenience to indicate that the 293 permitted value of this string is a (UTF-8 encoded) dotted-decimal 294 representation of an OBJECT IDENTIFIER. Although an LDAPOID is 295 encoded as an OCTET STRING, values are limited to the definition of 296 numericoid given in Section 1.3 of [Models]. 298 LDAPOID ::= OCTET STRING -- Constrained to numericoid [Models] 300 For example, 302 1.3.6.1.4.1.1466.1.2.3 304 4.1.3. Distinguished Name and Relative Distinguished Name 306 An LDAPDN and a RelativeLDAPDN are respectively defined to be the 307 representation of a distinguished-name and a relative-distinguished- 308 name after encoding according to the specification in [LDAPDN]. 310 LDAPDN ::= LDAPString 311 -- Constrained to distinguishedName [LDAPDN] 313 RelativeLDAPDN ::= LDAPString 314 -- Constrained to name-component [LDAPDN] 316 4.1.4. Attribute Descriptions 318 The definition and encoding rules for attribute descriptions are 319 defined in Section 2.5 of [Models]. Briefly, an attribute description 320 is an attribute type and zero or more options. 322 Lightweight Directory Access Protocol Version 3 324 AttributeDescription ::= LDAPString 325 -- Constrained to attributedescription 326 -- [Models] 328 An AttributeDescriptionList describes a list of 0 or more attribute 329 descriptions. (A list of zero elements has special significance in 330 the Search request.) 332 AttributeDescriptionList ::= SEQUENCE OF 333 AttributeDescription 335 4.1.5. Attribute Value 337 A field of type AttributeValue is an OCTET STRING containing an 338 encoded attribute value data type. The value is encoded according to 339 its LDAP-specific encoding definition. The LDAP-specific encoding 340 definitions for different syntaxes and attribute types may be found 341 in other documents and in particular [Syntaxes]. 343 AttributeValue ::= OCTET STRING 345 Note that there is no defined limit on the size of this encoding; 346 thus protocol values may include multi-megabyte attributes (e.g. 347 photographs). 349 Attributes may be defined which have arbitrary and non-printable 350 syntax. Implementations MUST NOT display nor attempt to decode as 351 ASN.1, a value if its syntax is not known. The implementation may 352 attempt to discover the subschema of the source entry, and retrieve 353 the values of attributeTypes from it. 355 Clients MUST NOT send attribute values in a request that are not 356 valid according to the syntax defined for the attributes. 358 4.1.6. Attribute Value Assertion 360 The AttributeValueAssertion type definition is similar to the one in 361 the X.500 directory standards. It contains an attribute description 362 and a matching rule assertion value suitable for that type. 364 AttributeValueAssertion ::= SEQUENCE { 365 attributeDesc AttributeDescription, 366 assertionValue AssertionValue } 368 AssertionValue ::= OCTET STRING 370 The syntax of the AssertionValue depends on the context of the LDAP 371 operation being performed. For example, the syntax of the EQUALITY 372 matching rule for an attribute is used when performing a Compare 373 operation. Often this is the same syntax used for values of the 374 attribute type, but in some cases the assertion syntax differs from 375 Lightweight Directory Access Protocol Version 3 377 the value syntax. See objectIdentiferFirstComponentMatch in 378 [Syntaxes] for an example. 380 4.1.7. Attribute 382 An attribute consists of an attribute description and one or more 383 values of that attribute description. (Though attributes MUST have at 384 least one value when stored, due to access control restrictions the 385 set may be empty when transferred from the server to the client. This 386 is described in section 4.5.2, concerning the PartialAttributeList 387 type.) 389 Attribute ::= SEQUENCE { 390 type AttributeDescription, 391 vals SET OF AttributeValue } 393 Each attribute value is distinct in the set (no duplicates). The set 394 of attribute values is unordered. Implementations MUST NOT reply upon 395 any apparent ordering being repeatable. 397 4.1.8. Matching Rule Identifier 399 Matching rules are defined in 4.1.3 of [Models]. A matching rule is 400 identified in the LDAP protocol by the printable representation of 401 either its numericoid, or one of its short name descriptors, e.g. 402 "caseIgnoreIA5Match" or "1.3.6.1.4.1.453.33.33". 404 MatchingRuleId ::= LDAPString 406 Servers which support matching rules for use in the extensibleMatch 407 search filter MUST list the matching rules they implement in 408 subschema entries, using the matchingRules attributes. The server 409 SHOULD also list there, using the matchingRuleUse attribute, the 410 attribute types with which each matching rule can be used. More 411 information is given in section 4.5 of [Syntaxes]. 413 4.1.9. Result Message 415 The LDAPResult is the construct used in this protocol to return 416 success or failure indications from servers to clients. To various 417 requests, servers will return responses of LDAPResult or responses 418 containing the components of LDAPResult to indicate the final status 419 of a protocol operation request. 421 LDAPResult ::= SEQUENCE { 422 resultCode ENUMERATED { 423 success (0), 424 operationsError (1), 425 protocolError (2), 426 timeLimitExceeded (3), 427 sizeLimitExceeded (4), 428 Lightweight Directory Access Protocol Version 3 430 compareFalse (5), 431 compareTrue (6), 432 authMethodNotSupported (7), 433 strongAuthRequired (8), 434 -- 9 reserved -- 435 referral (10), 436 adminLimitExceeded (11), 437 unavailableCriticalExtension (12), 438 confidentialityRequired (13), 439 saslBindInProgress (14), 440 noSuchAttribute (16), 441 undefinedAttributeType (17), 442 inappropriateMatching (18), 443 constraintViolation (19), 444 attributeOrValueExists (20), 445 invalidAttributeSyntax (21), 446 -- 22-31 unused -- 447 noSuchObject (32), 448 aliasProblem (33), 449 invalidDNSyntax (34), 450 -- 35 reserved for undefined isLeaf -- 451 aliasDereferencingProblem (36), 452 -- 37-47 unused -- 453 inappropriateAuthentication (48), 454 invalidCredentials (49), 455 insufficientAccessRights (50), 456 busy (51), 457 unavailable (52), 458 unwillingToPerform (53), 459 loopDetect (54), 460 -- 55-63 unused -- 461 namingViolation (64), 462 objectClassViolation (65), 463 notAllowedOnNonLeaf (66), 464 notAllowedOnRDN (67), 465 entryAlreadyExists (68), 466 objectClassModsProhibited (69), 467 -- 70 reserved for CLDAP -- 468 affectsMultipleDSAs (71), 469 -- 72-79 unused -- 470 other (80), 471 ... }, 472 -- 81-90 reserved for APIs -- 473 matchedDN LDAPDN, 474 diagnosticMessage LDAPString, 475 referral [3] Referral OPTIONAL } 477 The result codes enumeration is extensible as defined in Section 3.5 478 of [LDAPIANA]. The meanings of the result codes are given in Appendix 479 A. 481 The diagnosticMessage field of this construct may, at the server's 482 option, be used to return a string containing a textual, human- 483 readable (terminal control and page formatting characters should be 484 Lightweight Directory Access Protocol Version 3 486 avoided) diagnostic message. As this diagnostic message is not 487 standardized, implementations MUST NOT rely on the values returned. 488 If the server chooses not to return a textual diagnostic, the 489 diagnosticMessage field of the LDAPResult type MUST contain a zero 490 length string. 492 For certain result codes (typically, but not restricted to 493 noSuchObject, aliasProblem, invalidDNSyntax and 494 aliasDereferencingProblem), the matchedDN field is set to the name of 495 the lowest entry (object or alias) in the directory that was matched. 496 If no aliases were dereferenced while attempting to locate the entry, 497 this will be a truncated form of the name provided, or if aliases 498 were dereferenced, of the resulting name, as defined in section 12.5 499 of [X.511]. The matchedDN field contains a zero length string with 500 all other result codes. 502 4.1.10. Referral 504 The referral result code indicates that the contacted server does not 505 hold the target entry of the request. The referral field is present 506 in an LDAPResult if the LDAPResult.resultCode field value is 507 referral, and absent with all other result codes. It contains one or 508 more references to one or more servers or services that may be 509 accessed via LDAP or other protocols. Referrals can be returned in 510 response to any operation request (except unbind and abandon which do 511 not have responses). At least one URL MUST be present in the 512 Referral. 514 During a search operation, after the baseObject is located, and 515 entries are being evaluated, the referral is not returned. Instead, 516 continuation references, described in section 4.5.3, are returned 517 when the search scope spans multiple naming contexts, and several 518 different servers would need to be contacted to complete the 519 operation. 521 Referral ::= SEQUENCE OF LDAPURL -- one or more 523 LDAPURL ::= LDAPString -- limited to characters permitted in 524 -- URLs 526 If the client wishes to progress the operation, it MUST follow the 527 referral by contacting one of the servers. If multiple URLs are 528 present, the client assumes that any URL may be used to progress the 529 operation. 531 URLs for servers implementing the LDAP protocol are written according 532 to [LDAPURL]. If an alias was dereferenced, the part of the URL 533 MUST be present, with the new target object name. If the part is 534 present, the client MUST use this name in its next request to 535 progress the operation, and if it is not present the client will use 536 the same name as in the original request. Some servers (e.g. 537 participating in distributed indexing) may provide a different filter 538 in a referral for a search operation. If the filter part of the URL 539 Lightweight Directory Access Protocol Version 3 541 is present in an LDAPURL, the client MUST use this filter in its next 542 request to progress this search, and if it is not present the client 543 MUST use the same filter as it used for that search. Other aspects of 544 the new request may be the same or different as the request which 545 generated the referral. 547 Note that UTF-8 characters appearing in a DN or search filter may not 548 be legal for URLs (e.g. spaces) and MUST be escaped using the % 549 method in [RFC2396]. 551 Other kinds of URLs may be returned, so long as the operation could 552 be performed using that protocol. 554 4.1.11. Controls 556 A control is a way to specify extension information for an LDAP 557 message. A control only alters the semantics of the message it is 558 attached to. 560 Controls ::= SEQUENCE OF Control 562 Control ::= SEQUENCE { 563 controlType LDAPOID, 564 criticality BOOLEAN DEFAULT FALSE, 565 controlValue OCTET STRING OPTIONAL } 567 The controlType field MUST be a UTF-8 encoded dotted-decimal 568 representation of an OBJECT IDENTIFIER which uniquely identifies the 569 control. This prevents conflicts between control names. 571 The criticality field is either TRUE or FALSE and only applies to 572 request messages that have a corresponding response message. For all 573 other messages (such as abandonRequest, unbindRequest and all 574 response messages), the criticality field is treated as FALSE. 576 If the server recognizes the control type and it is appropriate for 577 the operation, the server will make use of the control when 578 performing the operation. 580 If the server does not recognize the control type or it is not 581 appropriate for the operation, and the criticality field is TRUE, the 582 server MUST NOT perform the operation, and MUST instead return the 583 resultCode unavailableCriticalExtension. 585 If the control is unrecognized or inappropriate but the criticality 586 field is FALSE, the server MUST ignore the control. 588 The controlValue contains any information associated with the 589 control, and its format is defined for the control. Implementations 590 MUST be prepared to handle arbitrary contents of the controlValue 591 octet string, including zero bytes. It is absent only if there is no 592 value information which is associated with a control of its type. 594 Lightweight Directory Access Protocol Version 3 596 This document does not specify any controls. Controls may be 597 specified in other documents. The specification of a control consists 598 of: 600 - the OBJECT IDENTIFIER assigned to the control, 602 - whether the control is always noncritical, always critical, or 603 critical at the client's option, 605 - the format of the controlValue contents of the control, 607 - the semantics of the control, 609 - and optionally, semantics regarding the combination of the control 610 with other controls. 612 Servers list the controlType of all request controls they recognize 613 in the supportedControl attribute [Models] in the root DSE. 615 Controls should not be combined unless the semantics of the 616 combination has been specified. The semantics of control 617 combinations, if specified, are generally found in the control 618 specification most recently published. In the absence of combination 619 semantics, the behavior of the operation is undefined. 620 Additionally, the order of a combination of controls in the SEQUENCE 621 is ignored unless the control specification(s) describe(s) 622 combination semantics. 624 4.2. Bind Operation 626 The function of the Bind Operation is to allow authentication 627 information to be exchanged between the client and server. Prior to 628 the first BindRequest, the implied identity is anonymous. Refer to 629 [AuthMeth] for the authentication-related semantics of this 630 operation. 632 The Bind Request is defined as follows: 634 BindRequest ::= [APPLICATION 0] SEQUENCE { 635 version INTEGER (1 .. 127), 636 name LDAPDN, 637 authentication AuthenticationChoice } 639 AuthenticationChoice ::= CHOICE { 640 simple [0] OCTET STRING, 641 -- 1 and 2 reserved 642 sasl [3] SaslCredentials, 643 ... } 645 SaslCredentials ::= SEQUENCE { 646 mechanism LDAPString, 647 credentials OCTET STRING OPTIONAL } 648 Lightweight Directory Access Protocol Version 3 650 Parameters of the Bind Request are: 652 - version: A version number indicating the version of the protocol 653 to be used in this protocol association. This document describes 654 version 3 of the LDAP protocol. Note that there is no version 655 negotiation, and the client just sets this parameter to the 656 version it desires. If the server does not support the specified 657 version, it responds with protocolError in the resultCode field of 658 the BindResponse. 660 - name: The name of the directory object that the client wishes to 661 bind as. This field may take on a null value (a zero length 662 string) for the purposes of anonymous binds ([AuthMeth] section 7) 663 or when using SASL authentication ([AuthMeth] section 4.3). Server 664 behavior is undefined when the name is a null value, simple 665 authentication is used, and a password is specified. The server 666 SHOULD NOT perform any alias dereferencing in determining the 667 object to bind as. 669 - authentication: information used to authenticate the name, if any, 670 provided in the Bind Request. This type is extensible as defined 671 in Section 3.6 of [LDAPIANA]. Servers that do not support a choice 672 supplied by a client will return authMethodNotSupported in the 673 result code of the BindResponse. The simple form of an 674 AuthenticationChoice specifies a simple password to be used for 675 authentication. To improve matching, applications SHOULD prepare 676 textual strings used as passwords. Applications which prepare 677 textural strings used as password are REQUIRED to prepare them by 678 transcoding the string to [Unicode], apply [SASLprep], and encode 679 as UTF-8. 681 Authorization is the use of this authentication information when 682 performing operations. Authorization MAY be affected by factors 683 outside of the LDAP Bind Request, such as lower layer security 684 services. 686 4.2.1. Processing of the Bind Request 688 Upon receipt of a BindRequest, the server MUST ensure there are no 689 outstanding operations in progress on the connection (this simplifies 690 server implementation). The server then proceeds to authenticate the 691 client in either a single-step, or multi-step bind process. Each step 692 requires the server to return a BindResponse to indicate the status 693 of authentication. 695 If the client did not bind before sending a request and receives an 696 operationsError, it may then send a Bind Request. If this also fails 697 or the client chooses not to bind on the existing connection, it may 698 close the connection, reopen it and begin again by first sending a 699 PDU with a Bind Request. This will aid in interoperating with servers 700 implementing other versions of LDAP. 702 Lightweight Directory Access Protocol Version 3 704 Clients MAY send multiple Bind Requests on a connection to change 705 their credentials. Authentication from earlier binds is subsequently 706 ignored. A failed or abandoned Bind Operation has the effect of 707 leaving the LDAP association in an anonymous state. To arrive at a 708 known authentication state after abandoning a bind operation, clients 709 may unbind, rebind, or make use of the BindResponse. If a SASL 710 transfer encryption or integrity mechanism has been negotiated, and 711 that mechanism does not support the changing of credentials from one 712 identity to another, then the client MUST instead establish a new 713 connection. 715 For some SASL authentication mechanisms, it may be necessary for the 716 client to invoke the BindRequest multiple times. This is indicated by 717 the server sending a BindResponse with the resultCode set to 718 saslBindInProgress. This indicates that the server requires the 719 client to send a new bind request, with the same sasl mechanism, to 720 continue the authentication process. If at any stage the client 721 wishes to abort the bind process it MAY unbind and then drop the 722 underlying connection. Clients MUST NOT invoke operations between two 723 Bind Requests made as part of a multi-stage bind. 725 A client may abort a SASL bind negotiation by sending a BindRequest 726 with a different value in the mechanism field of SaslCredentials, or 727 an AuthenticationChoice other than sasl. 729 If the client sends a BindRequest with the sasl mechanism field as an 730 empty string, the server MUST return a BindResponse with 731 authMethodNotSupported as the resultCode. This will allow clients to 732 abort a negotiation if it wishes to try again with the same SASL 733 mechanism. 735 4.2.2. Bind Response 737 The Bind Response is defined as follows. 739 BindResponse ::= [APPLICATION 1] SEQUENCE { 740 COMPONENTS OF LDAPResult, 741 serverSaslCreds [7] OCTET STRING OPTIONAL } 743 BindResponse consists simply of an indication from the server of the 744 status of the client's request for authentication. 746 A successful bind operation is indicated by a BindResponse with a 747 resultCode set to success (0). Otherwise, an appropriate resultCode 748 is set in the BindResponse. For bind, the protocolError (2) 749 resultCode may be used to indicate that the version number supplied 750 by the client is unsupported. 752 If the client receives a BindResponse response where the resultCode 753 was protocolError, it MUST close the connection as the server will be 754 unwilling to accept further operations. (This is for compatibility 755 with earlier versions of LDAP, in which the bind was always the first 756 operation, and there was no negotiation.) 757 Lightweight Directory Access Protocol Version 3 759 The serverSaslCreds are used as part of a SASL-defined bind mechanism 760 to allow the client to authenticate the server to which it is 761 communicating, or to perform "challenge-response" authentication. If 762 the client bound with the simple choice, or the SASL mechanism does 763 not require the server to return information to the client, then this 764 field is not to be included in the result. 766 4.3. Unbind Operation 768 The function of the Unbind Operation is to terminate an LDAP 769 association and connection. The Unbind Operation is defined as 770 follows: 772 UnbindRequest ::= [APPLICATION 2] NULL 774 The Unbind Operation has no response defined. Upon transmission of an 775 UnbindRequest, a protocol client MUST assume that the LDAP 776 association is terminated. Upon receipt of an UnbindRequest, a 777 protocol server MUST assume that the requesting client has terminated 778 the association and that all outstanding requests may be discarded, 779 and MUST close the connection. 781 4.4. Unsolicited Notification 783 An unsolicited notification is an LDAPMessage sent from the server to 784 the client which is not in response to any LDAPMessage received by 785 the server. It is used to signal an extraordinary condition in the 786 server or in the connection between the client and the server. The 787 notification is of an advisory nature, and the server will not expect 788 any response to be returned from the client. 790 The unsolicited notification is structured as an LDAPMessage in which 791 the messageID is 0 and protocolOp is of the extendedResp form. The 792 responseName field of the ExtendedResponse is present. The LDAPOID 793 value MUST be unique for this notification, and not be used in any 794 other situation. 796 One unsolicited notification (Notice of Disconnection) is defined in 797 this document. 799 4.4.1. Notice of Disconnection 801 This notification may be used by the server to advise the client that 802 the server is about to close the connection due to an error 803 condition. Note that this notification is NOT a response to an unbind 804 requested by the client: the server MUST follow the procedures of 805 section 4.3. This notification is intended to assist clients in 806 distinguishing between an error condition and a transient network 807 failure. As with a connection close due to network failure, the 808 Lightweight Directory Access Protocol Version 3 810 client MUST NOT assume that any outstanding requests which modified 811 the directory have succeeded or failed. 813 The responseName is 1.3.6.1.4.1.1466.20036, the response field is 814 absent, and the resultCode is used to indicate the reason for the 815 disconnection. 817 The following resultCode values have these meanings when used in this 818 notification: 820 - protocolError: The server has received data from the client in 821 which the LDAPMessage structure could not be parsed. 823 - strongAuthRequired: The server has detected that an established 824 underlying security association protecting communication between 825 the client and server has unexpectedly failed or been compromised. 827 - unavailable: This server will stop accepting new connections and 828 operations on all existing connections, and be unavailable for an 829 extended period of time. The client may make use of an alternative 830 server. 832 After sending this notice, the server MUST close the connection. 833 After receiving this notice, the client MUST NOT transmit any further 834 on the connection, and may abruptly close the connection. 836 4.5. Search Operation 838 The Search Operation allows a client to request that a search be 839 performed on its behalf by a server. This can be used to read 840 attributes from a single entry, from entries immediately below a 841 particular entry, or a whole subtree of entries. 843 4.5.1. Search Request 845 The Search Request is defined as follows: 847 SearchRequest ::= [APPLICATION 3] SEQUENCE { 848 baseObject LDAPDN, 849 scope ENUMERATED { 850 baseObject (0), 851 singleLevel (1), 852 wholeSubtree (2) }, 853 derefAliases ENUMERATED { 854 neverDerefAliases (0), 855 derefInSearching (1), 856 derefFindingBaseObj (2), 857 derefAlways (3) }, 858 sizeLimit INTEGER (0 .. maxInt), 859 timeLimit INTEGER (0 .. maxInt), 860 typesOnly BOOLEAN, 861 filter Filter, 862 Lightweight Directory Access Protocol Version 3 864 attributes AttributeDescriptionList } 866 Filter ::= CHOICE { 867 and [0] SET SIZE (1..MAX) OF Filter, 868 or [1] SET SIZE (1..MAX) OF Filter, 869 not [2] Filter, 870 equalityMatch [3] AttributeValueAssertion, 871 substrings [4] SubstringFilter, 872 greaterOrEqual [5] AttributeValueAssertion, 873 lessOrEqual [6] AttributeValueAssertion, 874 present [7] AttributeDescription, 875 approxMatch [8] AttributeValueAssertion, 876 extensibleMatch [9] MatchingRuleAssertion } 878 SubstringFilter ::= SEQUENCE { 879 type AttributeDescription, 880 -- at least one must be present, 881 -- initial and final can occur at most once 882 substrings SEQUENCE OF CHOICE { 883 initial [0] AssertionValue, 884 any [1] AssertionValue, 885 final [2] AssertionValue } } 887 MatchingRuleAssertion ::= SEQUENCE { 888 matchingRule [1] MatchingRuleId OPTIONAL, 889 type [2] AttributeDescription OPTIONAL, 890 matchValue [3] AssertionValue, 891 dnAttributes [4] BOOLEAN DEFAULT FALSE } 893 Parameters of the Search Request are: 895 - baseObject: An LDAPDN that is the base object entry relative to 896 which the search is to be performed. 898 - scope: An indicator of the scope of the search to be performed. 899 The semantics of the possible values of this field are identical 900 to the semantics of the scope field in the X.511 Search Operation. 902 - derefAliases: An indicator as to how alias objects (as defined in 903 [X.501]) are to be handled in searching. The semantics of the 904 possible values of this field are: 906 neverDerefAliases: Do not dereference aliases in searching 907 or in locating the base object of the search. 909 derefInSearching: While searching, dereference any alias 910 object subordinate to the base object which is also in the 911 search scope. The filter is applied to the dereferenced 912 object(s). If the search scope is wholeSubtree, the search 913 continues in the subtree of any dereferenced object. 914 Aliases in that subtree are also dereferenced. Servers 915 SHOULD detect looping in this process to prevent denial of 916 service attacks and duplicate entries. 918 Lightweight Directory Access Protocol Version 3 920 derefFindingBaseObj: Dereference aliases in locating the 921 base object of the search, but not when searching 922 subordinates of the base object. 924 derefAlways: Dereference aliases both in searching and in 925 locating the base object of the search. 927 - sizeLimit: A size limit that restricts the maximum number of 928 entries to be returned as a result of the search. A value of 0 in 929 this field indicates that no client-requested size limit 930 restrictions are in effect for the search. Servers may enforce a 931 maximum number of entries to return. 933 - timeLimit: A time limit that restricts the maximum time (in 934 seconds) allowed for a search. A value of 0 in this field 935 indicates that no client-requested time limit restrictions are in 936 effect for the search. 938 - typesOnly: An indicator as to whether search results will contain 939 both attribute descriptions and values, or just attribute 940 descriptions. Setting this field to TRUE causes only attribute 941 descriptions (no values) to be returned. Setting this field to 942 FALSE causes both attribute descriptions and values to be 943 returned. 945 - filter: A filter that defines the conditions that must be 946 fulfilled in order for the search to match a given entry. 948 The 'and', 'or' and 'not' choices can be used to form combinations 949 of filters. At least one filter element MUST be present in an 950 'and' or 'or' choice. The others match against individual 951 attribute values of entries in the scope of the search. 952 (Implementor's note: the 'not' filter is an example of a tagged 953 choice in an implicitly-tagged module. In BER this is treated as 954 if the tag was explicit.) 956 A server MUST evaluate filters according to the three-valued logic 957 of X.511 (1993) section 7.8.1. In summary, a filter is evaluated 958 to either "TRUE", "FALSE" or "Undefined". If the filter evaluates 959 to TRUE for a particular entry, then the attributes of that entry 960 are returned as part of the search result (subject to any 961 applicable access control restrictions). If the filter evaluates 962 to FALSE or Undefined, then the entry is ignored for the search. 964 A filter of the "and" choice is TRUE if all the filters in the SET 965 OF evaluate to TRUE, FALSE if at least one filter is FALSE, and 966 otherwise Undefined. A filter of the "or" choice is FALSE if all 967 of the filters in the SET OF evaluate to FALSE, TRUE if at least 968 one filter is TRUE, and Undefined otherwise. A filter of the "not" 969 choice is TRUE if the filter being negated is FALSE, FALSE if it 970 is TRUE, and Undefined if it is Undefined. 972 The present match evaluates to TRUE where there is an attribute or 973 subtype of the specified attribute description present in an 974 Lightweight Directory Access Protocol Version 3 976 entry, and FALSE otherwise (including a presence test with an 977 unrecognized attribute description.) 979 The matching rule for equalityMatch filter items is defined by the 980 EQUALITY matching rule for the attribute type. 982 The matching rule for AssertionValues in a substrings filter item 983 is defined by the SUBSTR matching rule for the attribute type. 985 The matching rule for greaterOrEqual and lessOrEqual filter items 986 is defined by the ORDERING matching rule for the attribute type. 988 The matching semantics for approxMatch filter items is 989 implementation-defined. If approximate matching is not supported 990 by the server, the filter item should be treated as an 991 equalityMatch. 993 The extensibleMatch is new in this version of LDAP. If the 994 matchingRule field is absent, the type field MUST be present, and 995 the equality match is performed for that type. If the type field 996 is absent and matchingRule is present, the matchValue is compared 997 against all attributes in an entry which support that 998 matchingRule, and the matchingRule determines the syntax for the 999 assertion value (the filter item evaluates to TRUE if it matches 1000 with at least one attribute in the entry, FALSE if it does not 1001 match any attribute in the entry, and Undefined if the 1002 matchingRule is not recognized or the assertionValue cannot be 1003 parsed.) If the type field is present and matchingRule is present, 1004 the matchingRule MUST be one permitted for use with that type, 1005 otherwise the filter item is undefined. If the dnAttributes field 1006 is set to TRUE, the match is applied against all the 1007 AttributeValueAssertions in an entry's distinguished name as well, 1008 and also evaluates to TRUE if there is at least one attribute in 1009 the distinguished name for which the filter item evaluates to 1010 TRUE. (Editors note: The dnAttributes field is present so that 1011 there does not need to be multiple versions of generic matching 1012 rules such as for word matching, one to apply to entries and 1013 another to apply to entries and dn attributes as well). 1015 A filter item evaluates to Undefined when the server would not be 1016 able to determine whether the assertion value matches an entry. If 1017 an attribute description in an equalityMatch, substrings, 1018 greaterOrEqual, lessOrEqual, approxMatch or extensibleMatch filter 1019 is not recognized by the server, a matching rule id in the 1020 extensibleMatch is not recognized by the server, the assertion 1021 value cannot be parsed, or the type of filtering requested is not 1022 implemented, then the filter is Undefined. Thus for example if a 1023 server did not recognize the attribute type shoeSize, a filter of 1024 (shoeSize=*) would evaluate to FALSE, and the filters 1025 (shoeSize=12), (shoeSize>=12) and (shoeSize<=12) would evaluate to 1026 Undefined. 1028 Servers MUST NOT return errors if attribute descriptions or 1029 matching rule ids are not recognized, or assertion values cannot 1030 Lightweight Directory Access Protocol Version 3 1032 be parsed. More details of filter processing are given in section 1033 7.8 of [X.511]. 1035 - attributes: A list of the attributes to be returned from each 1036 entry which matches the search filter. There are two special 1037 values which may be used: an empty list with no attributes, and 1038 the attribute description string "*". Both of these signify that 1039 all user attributes are to be returned. (The "*" allows the client 1040 to request all user attributes in addition to any specified 1041 operational attributes). 1043 Attributes MUST be named at most once in the list, and are 1044 returned at most once in an entry. If there are attribute 1045 descriptions in the list which are not recognized, they are 1046 ignored by the server. 1048 If the client does not want any attributes returned, it can 1049 specify a list containing only the attribute with OID "1.1". This 1050 OID was chosen arbitrarily and does not correspond to any 1051 attribute in use. 1053 Client implementors should note that even if all user attributes 1054 are requested, some attributes of the entry may not be included in 1055 search results due to access controls or other restrictions. 1056 Furthermore, servers will not return operational attributes, such 1057 as objectClasses or attributeTypes, unless they are listed by 1058 name, since there may be extremely large number of values for 1059 certain operational attributes. (A list of operational attributes 1060 for use in LDAP is given in [Syntaxes].) 1062 Note that an X.500 "list"-like operation can be emulated by the 1063 client requesting a one-level LDAP search operation with a filter 1064 checking for the presence of the objectClass attribute, and that an 1065 X.500 "read"-like operation can be emulated by a base object LDAP 1066 search operation with the same filter. A server which provides a 1067 gateway to X.500 is not required to use the Read or List operations, 1068 although it may choose to do so, and if it does, it must provide the 1069 same semantics as the X.500 search operation. 1071 4.5.2. Search Result 1073 The results of the search attempted by the server upon receipt of a 1074 Search Request are returned in Search Responses, which are LDAP 1075 messages containing either SearchResultEntry, SearchResultReference, 1076 or SearchResultDone data types. 1078 SearchResultEntry ::= [APPLICATION 4] SEQUENCE { 1079 objectName LDAPDN, 1080 attributes PartialAttributeList } 1082 PartialAttributeList ::= SEQUENCE OF SEQUENCE { 1083 type AttributeDescription, 1084 vals SET OF AttributeValue } 1085 Lightweight Directory Access Protocol Version 3 1087 -- implementors should note that the PartialAttributeList may 1088 -- have zero elements (if none of the attributes of that entry 1089 -- were requested, or could be returned), and that the vals set 1090 -- may also have zero elements (if types only was requested, or 1091 -- all values were excluded from the result.) 1093 SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL 1094 -- at least one LDAPURL element must be present 1096 SearchResultDone ::= [APPLICATION 5] LDAPResult 1098 Upon receipt of a Search Request, a server will perform the necessary 1099 search of the DIT. 1101 If the LDAP association is operating over a connection-oriented 1102 transport such as TCP, the server will return to the client a 1103 sequence of responses in separate LDAP messages. There may be zero or 1104 more responses containing SearchResultEntry, one for each entry found 1105 during the search. There may also be zero or more responses 1106 containing SearchResultReference, one for each area not explored by 1107 this server during the search. The SearchResultEntry and 1108 SearchResultReference PDUs may come in any order. Following all the 1109 SearchResultReference responses and all SearchResultEntry responses 1110 to be returned by the server, the server will return a response 1111 containing the SearchResultDone, which contains an indication of 1112 success, or detailing any errors that have occurred. 1114 Each entry returned in a SearchResultEntry will contain all 1115 appropriate attributes as specified in the attributes field of the 1116 Search Request. Return of attributes is subject to access control and 1117 other administrative policy. 1119 Some attributes may be constructed by the server and appear in a 1120 SearchResultEntry attribute list, although they are not stored 1121 attributes of an entry. Clients SHOULD NOT assume that all attributes 1122 can be modified, even if permitted by access control. 1124 If the server's schema defines a textual name for an attribute type, 1125 it SHOULD use a textual name for attributes of that attribute type by 1126 specifying one of the textual names as the value of the attribute 1127 type. Otherwise, the server uses the object identifier for the 1128 attribute type by specifying the object identifier, in ldapOID form, 1129 as the value of attribute type. If the server determines that 1130 returning a textual name will cause interoperability problems, it 1131 SHOULD return the ldapOID form of the attribute type. 1133 4.5.3. Continuation References in the Search Result 1135 If the server was able to locate the entry referred to by the 1136 baseObject but was unable to search all the entries in the scope at 1137 and under the baseObject, the server may return one or more 1138 SearchResultReference entries, each containing a reference to another 1139 set of servers for continuing the operation. A server MUST NOT return 1140 Lightweight Directory Access Protocol Version 3 1142 any SearchResultReference if it has not located the baseObject and 1143 thus has not searched any entries; in this case it would return a 1144 SearchResultDone containing a referral resultCode. 1146 If a server holds a copy or partial copy of the subordinate naming 1147 context, it may use the search filter to determine whether or not to 1148 return a SearchResultReference response. Otherwise 1149 SearchResultReference responses are always returned when in scope. 1151 The SearchResultReference is of the same data type as the Referral. 1152 URLs for servers implementing the LDAP protocol are written according 1153 to [LDAPURL]. The part MUST be present in the URL, with the new 1154 target object name. The client MUST use this name in its next 1155 request. Some servers (e.g. part of a distributed index exchange 1156 system) may provide a different filter in the URLs of the 1157 SearchResultReference. If the filter part of the URL is present in an 1158 LDAP URL, the client MUST use the new filter in its next request to 1159 progress the search, and if the filter part is absent the client will 1160 use again the same filter. If the originating search scope was 1161 singleLevel, the scope part of the URL will be baseObject. Other 1162 aspects of the new search request may be the same or different as the 1163 search which generated the continuation references. 1164 Other kinds of URLs may be returned so long as the operation could be 1165 performed using that protocol. 1167 The name of an unexplored subtree in a SearchResultReference need not 1168 be subordinate to the base object. 1170 In order to complete the search, the client MUST issue a new search 1171 operation for each SearchResultReference that is returned. Note that 1172 the abandon operation described in section 4.11 applies only to a 1173 particular operation sent on an association between a client and 1174 server, and if the client has multiple outstanding search operations, 1175 it MUST abandon each operation individually. 1177 4.5.3.1. Example 1179 For example, suppose the contacted server (hosta) holds the entry 1180 "DC=Example,DC=NET" and the entry "CN=Manager,DC=Example,DC=NET". It 1181 knows that either LDAP-capable servers (hostb) or (hostc) hold 1182 "OU=People,DC=Example,DC=NET" (one is the master and the other server 1183 a shadow), and that LDAP-capable server (hostd) holds the subtree 1184 "OU=Roles,DC=Example,DC=NET". If a subtree search of 1185 "DC=Example,DC=NET" is requested to the contacted server, it may 1186 return the following: 1188 SearchResultEntry for DC=Example,DC=NET 1189 SearchResultEntry for CN=Manager,DC=Example,DC=NET 1190 SearchResultReference { 1191 ldap://hostb/OU=People,DC=Example,DC=NET 1192 ldap://hostc/OU=People,DC=Example,DC=NET 1193 } 1194 SearchResultReference { 1195 Lightweight Directory Access Protocol Version 3 1197 ldap://hostd/OU=Roles,DC=Example,DC=NET 1198 } 1199 SearchResultDone (success) 1201 Client implementors should note that when following a 1202 SearchResultReference, additional SearchResultReference may be 1203 generated. Continuing the example, if the client contacted the server 1204 (hostb) and issued the search for the subtree 1205 "OU=People,DC=Example,DC=NET", the server might respond as follows: 1207 SearchResultEntry for OU=People,DC=Example,DC=NET 1208 SearchResultReference { 1209 ldap://hoste/OU=Managers,OU=People,DC=Example,DC=NET 1210 } 1211 SearchResultReference { 1212 ldap://hostf/OU=Consultants,OU=People,DC=Example,DC=NET 1213 } 1214 SearchResultDone (success) 1216 If the contacted server does not hold the base object for the search, 1217 then it will return a referral to the client. For example, if the 1218 client requests a subtree search of "DC=Example,DC=ORG" to hosta, the 1219 server may return only a SearchResultDone containing a referral. 1221 SearchResultDone (referral) { 1222 ldap://hostg/DC=Example,DC=ORG??sub 1223 } 1225 4.6. Modify Operation 1227 The Modify Operation allows a client to request that a modification 1228 of an entry be performed on its behalf by a server. The Modify 1229 Request is defined as follows: 1231 ModifyRequest ::= [APPLICATION 6] SEQUENCE { 1232 object LDAPDN, 1233 modification SEQUENCE OF SEQUENCE { 1234 operation ENUMERATED { 1235 add (0), 1236 delete (1), 1237 replace (2) }, 1238 modification AttributeTypeAndValues } } 1240 AttributeTypeAndValues ::= SEQUENCE { 1241 type AttributeDescription, 1242 vals SET OF AttributeValue } 1244 Parameters of the Modify Request are: 1246 - object: The object to be modified. The value of this field 1247 contains the DN of the entry to be modified. The server will not 1248 perform any alias dereferencing in determining the object to be 1249 modified. 1251 Lightweight Directory Access Protocol Version 3 1253 - modification: A list of modifications to be performed on the 1254 entry. The entire list of entry modifications MUST be performed in 1255 the order they are listed, as a single atomic operation. While 1256 individual modifications may violate the directory schema, the 1257 resulting entry after the entire list of modifications is 1258 performed MUST conform to the requirements of the directory 1259 schema. The values that may be taken on by the 'operation' field 1260 in each modification construct have the following semantics 1261 respectively: 1263 add: add values listed to the given attribute, creating the 1264 attribute if necessary; 1266 delete: delete values listed from the given attribute, 1267 removing the entire attribute if no values are listed, or 1268 if all current values of the attribute are listed for 1269 deletion; 1271 replace: replace all existing values of the given attribute 1272 with the new values listed, creating the attribute if it 1273 did not already exist. A replace with no value will delete 1274 the entire attribute if it exists, and is ignored if the 1275 attribute does not exist. 1277 The result of the modification attempted by the server upon receipt 1278 of a Modify Request is returned in a Modify Response, defined as 1279 follows: 1281 ModifyResponse ::= [APPLICATION 7] LDAPResult 1283 Upon receipt of a Modify Request, a server will perform the necessary 1284 modifications to the DIT. 1286 The server will return to the client a single Modify Response 1287 indicating either the successful completion of the DIT modification, 1288 or the reason that the modification failed. Note that due to the 1289 requirement for atomicity in applying the list of modifications in 1290 the Modify Request, the client may expect that no modifications of 1291 the DIT have been performed if the Modify Response received indicates 1292 any sort of error, and that all requested modifications have been 1293 performed if the Modify Response indicates successful completion of 1294 the Modify Operation. If the association changes or the connection 1295 fails, whether the modification occurred or not is indeterminate. 1297 The Modify Operation cannot be used to remove from an entry any of 1298 its distinguished values, those values which form the entry's 1299 relative distinguished name. An attempt to do so will result in the 1300 server returning the error notAllowedOnRDN. The Modify DN Operation 1301 described in section 4.9 is used to rename an entry. 1303 Note that due to the simplifications made in LDAP, there is not a 1304 direct mapping of the modifications in an LDAP ModifyRequest onto the 1305 EntryModifications of a DAP ModifyEntry operation, and different 1306 Lightweight Directory Access Protocol Version 3 1308 implementations of LDAP-DAP gateways may use different means of 1309 representing the change. If successful, the final effect of the 1310 operations on the entry MUST be identical. 1312 4.7. Add Operation 1314 The Add Operation allows a client to request the addition of an entry 1315 into the directory. The Add Request is defined as follows: 1317 AddRequest ::= [APPLICATION 8] SEQUENCE { 1318 entry LDAPDN, 1319 attributes AttributeList } 1321 AttributeList ::= SEQUENCE OF SEQUENCE { 1322 type AttributeDescription, 1323 vals SET OF AttributeValue } 1325 Parameters of the Add Request are: 1327 - entry: the Distinguished Name of the entry to be added. Note that 1328 the server will not dereference any aliases in locating the entry 1329 to be added. 1331 - attributes: the list of attributes that make up the content of the 1332 entry being added. Clients MUST include distinguished values 1333 (those forming the entry's own RDN) in this list, the objectClass 1334 attribute, and values of any mandatory attributes of the listed 1335 object classes. Clients MUST NOT supply NO-USER-MODIFICATION 1336 attributes such as the createTimestamp or creatorsName attributes, 1337 since the server maintains these automatically. 1339 The entry named in the entry field of the AddRequest MUST NOT exist 1340 for the AddRequest to succeed. The immediate superior (parent) of the 1341 object and alias entries to be added MUST exist. For example, if the 1342 client attempted to add "CN=JS,DC=Example,DC=NET", the 1343 "DC=Example,DC=NET" entry did not exist, and the "DC=NET" entry did 1344 exist, then the server would return the error noSuchObject with the 1345 matchedDN field containing "DC=NET". If the parent entry exists but 1346 is not in a naming context held by the server, the server SHOULD 1347 return a referral to the server holding the parent entry. 1349 Server implementations SHOULD NOT restrict where entries can be 1350 located in the directory unless DIT structure rules are in place. 1351 Some servers MAY allow the administrator to restrict the classes of 1352 entries which can be added to the directory. 1354 Upon receipt of an Add Request, a server will attempt to add the 1355 requested entry. The result of the add attempt will be returned to 1356 the client in the Add Response, defined as follows: 1358 AddResponse ::= [APPLICATION 9] LDAPResult 1359 Lightweight Directory Access Protocol Version 3 1361 A response of success indicates that the new entry is present in the 1362 directory. 1364 4.8. Delete Operation 1366 The Delete Operation allows a client to request the removal of an 1367 entry from the directory. The Delete Request is defined as follows: 1369 DelRequest ::= [APPLICATION 10] LDAPDN 1371 The Delete Request consists of the Distinguished Name of the entry to 1372 be deleted. Note that the server will not dereference aliases while 1373 resolving the name of the target entry to be removed, and that only 1374 leaf entries (those with no subordinate entries) can be deleted with 1375 this operation. 1377 The result of the delete attempted by the server upon receipt of a 1378 Delete Request is returned in the Delete Response, defined as 1379 follows: 1381 DelResponse ::= [APPLICATION 11] LDAPResult 1383 Upon receipt of a Delete Request, a server will attempt to perform 1384 the entry removal requested. The result of the delete attempt will be 1385 returned to the client in the Delete Response. 1387 4.9. Modify DN Operation 1389 The Modify DN Operation allows a client to change the leftmost (least 1390 significant) component of the name of an entry in the directory, 1391 and/or to move a subtree of entries to a new location in the 1392 directory. The Modify DN Request is defined as follows: 1394 ModifyDNRequest ::= [APPLICATION 12] SEQUENCE { 1395 entry LDAPDN, 1396 newrdn RelativeLDAPDN, 1397 deleteoldrdn BOOLEAN, 1398 newSuperior [0] LDAPDN OPTIONAL } 1400 Parameters of the Modify DN Request are: 1402 - entry: the Distinguished Name of the entry to be changed. This 1403 entry may or may not have subordinate entries. Note that the 1404 server will not dereference any aliases in locating the entry to 1405 be changed. 1407 - newrdn: the RDN that will form the leftmost component of the new 1408 name of the entry. 1410 - deleteoldrdn: a boolean parameter that controls whether the old 1411 RDN attribute values are to be retained as attributes of the 1412 entry, or deleted from the entry. 1414 Lightweight Directory Access Protocol Version 3 1416 - newSuperior: if present, this is the Distinguished Name of an 1417 existing object entry which becomes the immediate superior 1418 (parent)of the existing entry. 1420 The result of the name change attempted by the server upon receipt of 1421 a Modify DN Request is returned in the Modify DN Response, defined as 1422 follows: 1424 ModifyDNResponse ::= [APPLICATION 13] LDAPResult 1426 Upon receipt of a ModifyDNRequest, a server will attempt to perform 1427 the name change. The result of the name change attempt will be 1428 returned to the client in the Modify DN Response. 1430 For example, if the entry named in the "entry" parameter was "cn=John 1431 Smith,c=US", the newrdn parameter was "cn=John Cougar Smith", and the 1432 newSuperior parameter was absent, then this operation would attempt 1433 to rename the entry to be "cn=John Cougar Smith,c=US". If there was 1434 already an entry with that name, the operation would fail with error 1435 code entryAlreadyExists. 1437 The object named in newSuperior MUST exist. For example, if the 1438 client attempted to add "CN=JS,DC=Example,DC=NET", the 1439 "DC=Example,DC=NET" entry did not exist, and the "DC=NET" entry did 1440 exist, then the server would return the error noSuchObject with the 1441 matchedDN field containing "DC=NET". 1443 If the deleteoldrdn parameter is TRUE, the values forming the old RDN 1444 are deleted from the entry. If the deleteoldrdn parameter is FALSE, 1445 the values forming the old RDN will be retained as non-distinguished 1446 attribute values of the entry. The server may not perform the 1447 operation and return an error code if the setting of the deleteoldrdn 1448 parameter would cause a schema inconsistency in the entry. 1450 Note that X.500 restricts the ModifyDN operation to only affect 1451 entries that are contained within a single server. If the LDAP server 1452 is mapped onto DAP, then this restriction will apply, and the 1453 resultCode affectsMultipleDSAs will be returned if this error 1454 occurred. In general clients MUST NOT expect to be able to perform 1455 arbitrary movements of entries and subtrees between servers. 1457 4.10. Compare Operation 1459 The Compare Operation allows a client to compare an assertion 1460 provided with an entry in the directory. The Compare Request is 1461 defined as follows: 1463 CompareRequest ::= [APPLICATION 14] SEQUENCE { 1464 entry LDAPDN, 1465 ava AttributeValueAssertion } 1467 Parameters of the Compare Request are: 1469 Lightweight Directory Access Protocol Version 3 1471 - entry: the name of the entry to be compared with. Note that the 1472 server SHOULD NOT dereference any aliases in locating the entry to 1473 be compared with. 1475 - ava: the assertion with which an attribute in the entry is to be 1476 compared. 1478 The result of the compare attempted by the server upon receipt of a 1479 Compare Request is returned in the Compare Response, defined as 1480 follows: 1482 CompareResponse ::= [APPLICATION 15] LDAPResult 1484 Upon receipt of a Compare Request, a server will attempt to perform 1485 the requested comparison using the EQUALITY matching rule for the 1486 attribute type. The result of the comparison will be returned to the 1487 client in the Compare Response. Note that errors and the result of 1488 comparison are all returned in the same construct. 1490 Note that some directory systems may establish access controls which 1491 permit the values of certain attributes (such as userPassword) to be 1492 compared but not interrogated by other means. 1494 4.11. Abandon Operation 1496 The function of the Abandon Operation is to allow a client to request 1497 that the server abandon an outstanding operation. The Abandon Request 1498 is defined as follows: 1500 AbandonRequest ::= [APPLICATION 16] MessageID 1502 The MessageID MUST be that of an operation which was requested 1503 earlier in this LDAP association. The abandon request itself has its 1504 own message id. This is distinct from the id of the earlier operation 1505 being abandoned. 1507 There is no response defined in the Abandon Operation. Upon 1508 transmission of an Abandon Operation, the server MAY abandon the 1509 operation identified by the Message ID in the Abandon Request. 1510 Operation responses are not sent for successfully abandoned 1511 operations. Clients can determine that an operation has been 1512 abandoned by performing a subsequent bind operation. 1514 Abandon and Unbind operations cannot be abandoned. The ability to 1515 abandon other (particularly update) operations is at the discretion 1516 of the server. 1518 In the event that a server receives an Abandon Request on a Search 1519 Operation in the midst of transmitting responses to the search, that 1520 server MUST cease transmitting entry responses to the abandoned 1521 request immediately, and MUST NOT send the SearchResponseDone. Of 1522 Lightweight Directory Access Protocol Version 3 1524 course, the server MUST ensure that only properly encoded LDAPMessage 1525 PDUs are transmitted. 1527 Clients MUST NOT send abandon requests for the same operation 1528 multiple times, and MUST also be prepared to receive results from 1529 operations it has abandoned (since these may have been in transit 1530 when the abandon was requested, or are not able to be abandoned). 1532 Servers MUST discard abandon requests for message IDs they do not 1533 recognize, for operations which cannot be abandoned, and for 1534 operations which have already been abandoned. 1536 4.12. Extended Operation 1538 An extension mechanism has been added in this version of LDAP, in 1539 order to allow additional operations to be defined for services not 1540 available elsewhere in this protocol, for instance digitally signed 1541 operations and results. 1543 The extended operation allows clients to make requests and receive 1544 responses with predefined syntaxes and semantics. These may be 1545 defined in RFCs or be private to particular implementations. Each 1546 request MUST have a unique OBJECT IDENTIFIER assigned to it. 1548 ExtendedRequest ::= [APPLICATION 23] SEQUENCE { 1549 requestName [0] LDAPOID, 1550 requestValue [1] OCTET STRING OPTIONAL } 1552 The requestName is a dotted-decimal representation of the OBJECT 1553 IDENTIFIER corresponding to the request. The requestValue is 1554 information in a form defined by that request, encapsulated inside an 1555 OCTET STRING. 1557 The server will respond to this with an LDAPMessage containing the 1558 ExtendedResponse. 1560 ExtendedResponse ::= [APPLICATION 24] SEQUENCE { 1561 COMPONENTS OF LDAPResult, 1562 responseName [10] LDAPOID OPTIONAL, 1563 response [11] OCTET STRING OPTIONAL } 1565 If the server does not recognize the request name, it MUST return 1566 only the response fields from LDAPResult, containing the 1567 protocolError result code. 1569 4.13. Start TLS Operation 1571 The Start Transport Layer Security (StartTLS) operation provides the 1572 ability to establish Transport Layer Security [RFC2246] on an LDAP 1573 connection. 1575 4.13.1. Start TLS Request 1576 Lightweight Directory Access Protocol Version 3 1578 A client requests TLS establishment by transmitting a Start TLS 1579 request PDU to the server. The Start TLS request is defined in terms 1580 of an ExtendedRequest. The requestName is "1.3.6.1.4.1.1466.20037", 1581 and the requestValue field is absent. 1583 The client MUST NOT send any PDUs on this connection following this 1584 request until it receives a Start TLS extended response. 1586 4.13.2. Start TLS Response 1588 When a Start TLS request is made, servers supporting the operation 1589 MUST return a Start TLS response PDU to the requestor. The Start TLS 1590 response responseName is also "1.3.6.1.4.1.1466.20037", and the 1591 response field is absent. 1593 The server MUST set the resultCode field to either success or one of 1594 the other values outlined in section 4.13.2.2. 1596 4.13.2.1. "Success" Response 1598 If the Start TLS Response contains a resultCode of success, this 1599 indicates that the server is willing and able to negotiate TLS. Refer 1600 to section 5.3 of [AuthMeth] for details. 1602 4.13.2.2. Response other than "success" 1604 If the ExtendedResponse contains a resultCode other than success, 1605 this indicates that the server is unwilling or unable to negotiate 1606 TLS. The following resultCodes have these meanings for this 1607 operation: 1609 operationsError (operations sequencing incorrect; e.g. TLS already 1610 established) 1612 protocolError (TLS not supported or incorrect PDU structure) 1614 unavailable (e.g. some major problem with TLS, or server is 1615 shutting down) 1617 The server MUST return operationsError if the client violates any of 1618 the Start TLS extended operation sequencing requirements described in 1619 section 5.3 of [AuthMeth]. 1621 If the server does not support TLS (whether by design or by current 1622 configuration), it MUST set the resultCode to protocolError. The 1623 client's current association is unaffected if the server does not 1624 support TLS. The client MAY proceed with any LDAP operation, or it 1625 MAY close the connection. 1627 The server MUST return unavailable if it supports TLS but cannot 1628 establish a TLS connection for some reason, e.g. the certificate 1629 server not responding, it cannot contact its TLS implementation, or 1630 Lightweight Directory Access Protocol Version 3 1632 if the server is in process of shutting down. The client MAY retry 1633 the StartTLS operation, or it MAY proceed with any other LDAP 1634 operation, or it MAY close the LDAP connection. 1636 4.13.3. Closing a TLS Connection 1638 Two forms of TLS connection closure--graceful and abrupt--are 1639 supported. 1641 4.13.3.1. Graceful Closure 1643 Either the client or server MAY terminate the TLS connection and 1644 leave the LDAP connection intact by sending a TLS closure alert. 1646 Before sending a TLS closure alert, the client MUST either wait for 1647 any outstanding LDAP operations to complete, or explicitly abandon 1648 them. 1650 After the initiator of a close has sent a TLS closure alert, it MUST 1651 discard any TLS messages until it has received a TLS closure alert 1652 from the other party. It will cease to send TLS Record Protocol 1653 PDUs, and following the receipt of the alert, MAY send and receive 1654 LDAP PDUs. 1656 The other party, if it receives a TLS closure alert, MUST immediately 1657 transmit a TLS closure alert. It will subsequently cease to send TLS 1658 Record Protocol PDUs, and MAY send and receive LDAP PDUs. 1660 4.13.3.2. Abrupt Closure 1662 Either the client or server MAY abruptly close the TLS connection by 1663 dropping the underlying transfer protocol connection. In this 1664 circumstance, a server MAY send the client a Notice of Disconnection 1665 before dropping the underlying LDAP connection. 1667 5. Protocol Element Encodings and Transfer 1669 One underlying service is defined here. Clients and servers SHOULD 1670 implement the mapping of LDAP over TCP described in 5.2.1. 1672 5.1. Protocol Encoding 1674 The protocol elements of LDAP are encoded for exchange using the 1675 Basic Encoding Rules (BER) [X.690] of ASN.1 [X.680]. However, due to 1676 the high overhead involved in using certain elements of the BER, the 1677 following additional restrictions are placed on BER-encodings of LDAP 1678 protocol elements: 1680 (1) Only the definite form of length encoding will be used. 1682 (2) OCTET STRING values will be encoded in the primitive form only. 1684 Lightweight Directory Access Protocol Version 3 1686 (3) If the value of a BOOLEAN type is true, the encoding MUST have 1687 its contents octets set to hex "FF". 1689 (4) If a value of a type is its default value, it MUST be absent. 1690 Only some BOOLEAN and INTEGER types have default values in this 1691 protocol definition. 1693 These restrictions do not apply to ASN.1 types encapsulated inside of 1694 OCTET STRING values, such as attribute values, unless otherwise 1695 noted. 1697 5.2. Transfer Protocols 1699 This protocol is designed to run over connection-oriented, reliable 1700 transports, with all 8 bits in an octet being significant in the data 1701 stream. 1703 5.2.1. Transmission Control Protocol (TCP) 1705 The encoded LDAPMessage PDUs are mapped directly onto the TCP 1706 bytestream using the BER-based encoding described in section 5.1. It 1707 is recommended that server implementations running over the TCP 1708 provide a protocol listener on the assigned port, 389. Servers may 1709 instead provide a listener on a different port number. Clients MUST 1710 support contacting servers on any valid TCP port. 1712 6. Implementation Guidelines 1714 6.1. Server Implementations 1716 The server MUST be capable of recognizing all the mandatory attribute 1717 type names and implement the syntaxes specified in [Syntaxes]. 1718 Servers MAY also recognize additional attribute type names. 1720 6.2. Client Implementations 1722 Clients that follow referrals or search continuation references MUST 1723 ensure that they do not loop between servers. They MUST NOT 1724 repeatedly contact the same server for the same request with the same 1725 target entry name, scope and filter. Some clients use a counter that 1726 is incremented each time referral handling occurs for an operation, 1727 and these kinds of clients MUST be able to handle a DIT with at least 1728 ten layers of naming contexts between the root and a leaf entry. 1730 In the absence of prior agreements with servers, clients SHOULD NOT 1731 assume that servers support any particular schemas beyond those 1732 referenced in section 6.1. Different schemas can have different 1733 attribute types with the same names. The client can retrieve the 1734 Lightweight Directory Access Protocol Version 3 1736 subschema entries referenced by the subschemaSubentry attribute in 1737 the entries held by the server. 1739 7. Security Considerations 1741 When used with a connection-oriented transport, this version of the 1742 protocol provides facilities for simple authentication using a 1743 cleartext password, as well as any SASL mechanism [RFC2222]. SASL 1744 allows for integrity and privacy services to be negotiated. 1746 It is also permitted that the server can return its credentials to 1747 the client, if it chooses to do so. 1749 Use of cleartext password is strongly discouraged where the 1750 underlying transport service cannot guarantee confidentiality and may 1751 result in disclosure of the password to unauthorized parties. 1753 When used with SASL, it should be noted that the name field of the 1754 BindRequest is not protected against modification. Thus if the 1755 distinguished name of the client (an LDAPDN) is agreed through the 1756 negotiation of the credentials, it takes precedence over any value in 1757 the unprotected name field. 1759 Implementations which cache attributes and entries obtained via LDAP 1760 MUST ensure that access controls are maintained if that information 1761 is to be provided to multiple clients, since servers may have access 1762 control policies which prevent the return of entries or attributes in 1763 search results except to particular authenticated clients. For 1764 example, caches could serve result information only to the client 1765 whose request caused it to be in the cache. 1767 Protocol servers may return referrals which redirect protocol clients 1768 to peer servers. It is possible for a rogue application to inject 1769 such referrals into the data stream in an attempt to redirect a 1770 client to a rogue server. Protocol clients are advised to be aware of 1771 this, and possibly reject referrals when confidentiality measures are 1772 in place. Protocol clients are advised to ignore referrals from the 1773 Start TLS operation. 1775 8. Acknowledgements 1777 This document is an update to RFC 2251, by Mark Wahl, Tim Howes, and 1778 Steve Kille. Their work along with the input of individuals of the 1779 IETF LDAPEXT, LDUP, LDAPBIS, and other Working Groups is gratefully 1780 acknowledged. 1782 9. Normative References 1784 [X.500] ITU-T Rec. X.500, "The Directory: Overview of Concepts, 1785 Models and Service", 1993. 1787 Lightweight Directory Access Protocol Version 3 1789 [Roadmap] K. Zeilenga (editor), "LDAP: Technical Specification Road 1790 Map", draft-ietf-ldapbis-roadmap-xx.txt (a work in 1791 progress). 1793 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1794 Requirement Levels", RFC 2119, March 1997. 1796 [X.680] ITU-T Recommendation X.680 (1997) | ISO/IEC 8824-1:1998 1797 Information Technology - Abstract Syntax Notation One 1798 (ASN.1): Specification of basic notation 1800 [X.690] ITU-T Rec. X.690, "Specification of ASN.1 encoding rules: 1801 Basic, Canonical, and Distinguished Encoding Rules", 1994. 1803 [LDAPIANA] K. Zeilenga, "IANA Considerations for LDAP", draft-ietf- 1804 ldapbis-xx.txt (a work in progress). 1806 [ISO10646] Universal Multiple-Octet Coded Character Set (UCS) - 1807 Architecture and Basic Multilingual Plane, ISO/IEC 10646-1 1808 : 1993. 1810 [RFC2279] Yergeau, F., "UTF-8, a transformation format of Unicode 1811 and ISO 10646", RFC 2279, January 1998. 1813 [Models] K. Zeilenga, "LDAP: The Models", draft-ietf-ldapbis- 1814 models-xx.txt (a work in progress). 1816 [LDAPDN] K. Zeilenga (editor), "LDAP: String Representation of 1817 Distinguished Names", draft-ietf-ldapbis-dn-xx.txt, (a 1818 work in progress). 1820 [Syntaxes] K. Dally (editor), "LDAP: Syntaxes", draft-ietf-ldapbis- 1821 syntaxes-xx.txt, (a work in progress). 1823 [X.501] ITU-T Rec. X.501, "The Directory: Models", 1993. 1825 [X.511] ITU-T Rec. X.511, "The Directory: Abstract Service 1826 Definition", 1993. 1828 [RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter Uniform 1829 Resource Identifiers (URI): Generic Syntax", RFC 2396, 1830 August 1998. 1832 [AuthMeth] R. Harrison (editor), "LDAP: Authentication Methods", 1833 draft-ietf-ldapbis-authmeth-xx.txt, (a work in progress). 1835 [RFC2222] Meyers, J., "Simple Authentication and Security Layer", 1836 RFC 2222, October 1997. 1838 [SASLPrep] Zeilenga, K., "Stringprep profile for user names and 1839 passwords", draft-ietf-sasl-saslprep-xx.txt, (a work in 1840 progress). 1842 Lightweight Directory Access Protocol Version 3 1844 [Unicode] The Unicode Consortium, "The Unicode Standard, Version 1845 3.2.0" is defined by "The Unicode Standard, Version 3.0" 1846 (Reading, MA, Addison-Wesley, 2000. ISBN 0-201-61633-5), 1847 as amended by the "Unicode Standard Annex #27: Unicode 1848 3.1" (http://www.unicode.org/reports/tr27/) and by the 1849 "Unicode Standard Annex #28: Unicode 3.2" 1850 (http://www.unicode.org/reports/tr28/). 1852 10. Editor's Address 1854 Jim Sermersheim 1855 Novell, Inc. 1856 1800 South Novell Place 1857 Provo, Utah 84606, USA 1858 jimse@novell.com 1859 +1 801 861-3088 1860 Lightweight Directory Access Protocol Version 3 1862 Appendix A - LDAP Result Codes 1864 This normative appendix details additional considerations regarding 1865 LDAP result codes and provides a brief, general description of each 1866 LDAP result code enumerated in Section 4.1.10. 1868 Additional result codes MAY be defined for use with extensions. 1869 Client implementations SHALL treat any result code which they do not 1870 recognize as an unknown error condition. 1872 A.1 Non-Error Result Codes 1873 These result codes (called "non-error" result codes) do not indicate 1874 an error condition: 1875 success(0), 1876 compareTrue(6), 1877 compareFalse(7), 1878 referral(10), and 1879 saslBindInProgress(14). 1881 The success(0), compareTrue(6), and compare(7) result codes indicate 1882 successful completion (and, hence, are called to as "successful" 1883 result codes). 1885 The referral(10) and saslBindInProgress(14) indicate the client is 1886 required to take additional action to complete the operation 1888 A.2 Error Result Codes 1890 A.3 Classes and Precedence of Error Result Codes 1892 Result codes that indicate error conditions (and, hence, are called 1893 "error" result codes) fall into 6 classes. The following list 1894 specifies the precedence of error classes to be used when more than 1895 one error is detected [X511]: 1896 1) Name Errors (codes 32 - 34, 36) 1897 - a problem related to a name (DN or RDN), 1898 2) Update Errors (codes 64 - 69, 71) 1899 - a problem related to an update operation, 1900 3) Attribute Errors (codes 16 - 21) 1901 - a problem related to a supplied attribute, 1902 4) Security Errors (codes 8, 13, 48 - 50) 1903 - a security related problem, 1904 5) Service Problem (codes 3, 4, 7, 11, 12, 51 - 54, 80) 1905 - a problem related to the provision of the service, and 1906 6) Protocol Problem (codes 1, 2) 1907 - a problem related to protocol structure or semantics. 1909 If the server detects multiple errors simultaneously, the server 1910 SHOULD report the error with the highest precedence. 1912 Existing LDAP result codes are described as follows: 1914 success (0) 1915 Lightweight Directory Access Protocol Version 3 1917 Indicates successful completion of an operation. 1919 This result code is normally not returned by the compare 1920 operation, see compareFalse (5) and compareTrue (6). It is 1921 possible that a future extension mechanism would allow this 1922 to be returned by a compare operation. 1924 operationsError (1) 1926 Indicates that the operation is not properly sequenced with 1927 relation to other operations (of same or different type). 1929 For example, this code is returned if the client attempts to 1930 Start TLS [RFC2246] while there are other operations 1931 outstanding or if TLS was already established. 1933 protocolError (2) 1935 Indicates the server received data which has incorrect 1936 structure. 1938 For bind operation only, the code may be resulted to indicate 1939 the server does not support the requested protocol version. 1941 timeLimitExceeded (3) 1943 Indicates that the time limit specified by the client was 1944 exceeded before the operation could be completed. 1946 sizeLimitExceeded (4) 1948 Indicates that the size limit specified by the client was 1949 exceeded before the operation could be completed. 1951 compareFalse (5) 1953 Indicates that the operation successfully completes and the 1954 assertion has evaluated to FALSE. 1956 This result code is normally only returned by the compare 1957 operation. 1959 compareTrue (6) 1961 Indicates that the operation successfully completes and the 1962 assertion has evaluated to TRUE. 1964 Lightweight Directory Access Protocol Version 3 1966 This result code is normally only returned by the compare 1967 operation. 1969 authMethodNotSupported (7) 1971 Indicates that the authentication method or mechanism is not 1972 supported. 1974 strongAuthRequired (8) 1976 Except when returned in a Notice of Disconnect (see section 1977 4.4.1), this indicates that the server requires the client to 1978 authentication using a strong(er) mechanism. 1980 referral (10) 1982 Indicates that a referral needs to be chased to complete the 1983 operation (see section 4.1.11). 1985 adminLimitExceeded (11) 1987 Indicates that an administrative limit has been exceeded. 1989 unavailableCriticalExtension (12) 1991 Indicates that server cannot perform a critical extension 1992 (see section 4.1.12). 1994 confidentialityRequired (13) 1996 Indicates that data confidentiality protections are required. 1998 saslBindInProgress (14) 2000 Indicates the server requires the client to send a new bind 2001 request, with the same SASL mechanism, to continue the 2002 authentication process (see section 4.2). 2004 noSuchAttribute (16) 2006 Indicates that the named entry does not contain the specified 2007 attribute or attribute value. 2009 undefinedAttributeType (17) 2010 Lightweight Directory Access Protocol Version 3 2012 Indicates that a request field contains an undefined 2013 attribute type. 2015 inappropriateMatching (18) 2017 Indicates that a request cannot be completed due to an 2018 inappropriate matching. 2020 constraintViolation (19) 2022 Indicates that the client supplied an attribute value which 2023 does not conform to constraints placed upon it by the data 2024 model. 2026 For example, this code is returned when the multiple values 2027 are supplied to an attribute which has a SINGLE-VALUE 2028 constraint. 2030 attributeOrValueExists (20) 2032 Indicates that the client supplied an attribute or value to 2033 be added to an entry already exists. 2035 invalidAttributeSyntax (21) 2037 Indicates that a purported attribute value does not conform 2038 to the syntax of the attribute. 2040 noSuchObject (32) 2042 Indicates that the object does not exist in the DIT. 2044 aliasProblem (33) 2046 Indicates that an alias problem has occurred. Typically an 2047 alias has been dereferenced which names no object. 2049 invalidDNSyntax (34) 2051 Indicates that a LDAPDN or RelativeLDAPDN field (e.g. search 2052 base, target entry, ModifyDN newrdn, etc.) of a request does 2053 not conform to the required syntax or contains attribute 2054 values which do not conform to the syntax of the attribute's 2055 type. 2057 Lightweight Directory Access Protocol Version 3 2059 aliasDereferencingProblem (36) 2061 Indicates that a problem occurred while dereferencing an 2062 alias. Typically an alias was encountered in a situation 2063 where it was not allowed or where access was denied. 2065 inappropriateAuthentication (48) 2067 Indicates the server requires the client which had attempted 2068 to bind anonymously or without supplying credentials to 2069 provide some form of credentials, 2071 invalidCredentials (49) 2073 Indicates the supplied password or SASL credentials are 2074 invalid. 2076 insufficientAccessRights (50) 2078 Indicates that the client does not have sufficient access 2079 rights to perform the operation. 2081 busy (51) 2083 Indicates that the server is busy. 2085 unavailable (52) 2087 Indicates that the server is shutting down or a subsystem 2088 necessary to complete the operation is offline. 2090 unwillingToPerform (53) 2092 Indicates that the server is unwilling to perform the 2093 operation. 2095 loopDetect (54) 2097 Indicates that the server has detected an internal loop. 2099 namingViolation (64) 2101 Indicates that the entry name violates naming restrictions. 2103 objectClassViolation (65) 2104 Lightweight Directory Access Protocol Version 3 2106 Indicates that the entry violates object class restrictions. 2108 notAllowedOnNonLeaf (66) 2110 Indicates that operation is inappropriately acting upon a 2111 non-leaf entry. 2113 notAllowedOnRDN (67) 2115 Indicates that the operation is inappropriately attempting to 2116 remove a value which forms the entry's relative distinguished 2117 name. 2119 entryAlreadyExists (68) 2121 Indicates that the request cannot be added fulfilled as the 2122 entry already exists. 2124 objectClassModsProhibited (69) 2126 Indicates that the attempt to modify the object class(es) of 2127 an entry objectClass attribute is prohibited. 2129 For example, this code is returned when a when a client 2130 attempts to modify the structural object class of an entry. 2132 affectsMultipleDSAs (71) 2134 Indicates that the operation cannot be completed as it 2135 affects multiple servers (DSAs). 2137 other (80) 2139 Indicates the server has encountered an internal error. 2141 Lightweight Directory Access Protocol Version 3 2143 Appendix B - Complete ASN.1 Definition 2145 This appendix is normative. 2147 Lightweight-Directory-Access-Protocol-V3 DEFINITIONS 2148 IMPLICIT TAGS 2149 EXTENSIBILITY IMPLIED ::= 2151 BEGIN 2153 LDAPMessage ::= SEQUENCE { 2154 messageID MessageID, 2155 protocolOp CHOICE { 2156 bindRequest BindRequest, 2157 bindResponse BindResponse, 2158 unbindRequest UnbindRequest, 2159 searchRequest SearchRequest, 2160 searchResEntry SearchResultEntry, 2161 searchResDone SearchResultDone, 2162 searchResRef SearchResultReference, 2163 modifyRequest ModifyRequest, 2164 modifyResponse ModifyResponse, 2165 addRequest AddRequest, 2166 addResponse AddResponse, 2167 delRequest DelRequest, 2168 delResponse DelResponse, 2169 modDNRequest ModifyDNRequest, 2170 modDNResponse ModifyDNResponse, 2171 compareRequest CompareRequest, 2172 compareResponse CompareResponse, 2173 abandonRequest AbandonRequest, 2174 extendedReq ExtendedRequest, 2175 extendedResp ExtendedResponse, 2176 ... }, 2177 controls [0] Controls OPTIONAL } 2179 MessageID ::= INTEGER (0 .. maxInt) 2181 maxInt INTEGER ::= 2147483647 -- (2^^31 - 1) -- 2183 LDAPString ::= OCTET STRING -- UTF-8 encoded, 2184 -- [ISO10646] characters 2186 LDAPOID ::= OCTET STRING -- Constrained to numericoid [Models] 2188 LDAPDN ::= LDAPString 2190 RelativeLDAPDN ::= LDAPString 2192 AttributeDescription ::= LDAPString 2193 -- Constrained to attributedescription 2194 -- [Models] 2196 AttributeDescriptionList ::= SEQUENCE OF 2197 Lightweight Directory Access Protocol Version 3 2199 AttributeDescription 2201 AttributeValue ::= OCTET STRING 2203 AttributeValueAssertion ::= SEQUENCE { 2204 attributeDesc AttributeDescription, 2205 assertionValue AssertionValue } 2207 AssertionValue ::= OCTET STRING 2209 Attribute ::= SEQUENCE { 2210 type AttributeDescription, 2211 vals SET OF AttributeValue } 2213 MatchingRuleId ::= LDAPString 2215 LDAPResult ::= SEQUENCE { 2216 resultCode ENUMERATED { 2217 success (0), 2218 operationsError (1), 2219 protocolError (2), 2220 timeLimitExceeded (3), 2221 sizeLimitExceeded (4), 2222 compareFalse (5), 2223 compareTrue (6), 2224 authMethodNotSupported (7), 2225 strongAuthRequired (8), 2226 -- 9 reserved -- 2227 referral (10), 2228 adminLimitExceeded (11), 2229 unavailableCriticalExtension (12), 2230 confidentialityRequired (13), 2231 saslBindInProgress (14), 2232 noSuchAttribute (16), 2233 undefinedAttributeType (17), 2234 inappropriateMatching (18), 2235 constraintViolation (19), 2236 attributeOrValueExists (20), 2237 invalidAttributeSyntax (21), 2238 -- 22-31 unused -- 2239 noSuchObject (32), 2240 aliasProblem (33), 2241 invalidDNSyntax (34), 2242 -- 35 reserved for undefined isLeaf -- 2243 aliasDereferencingProblem (36), 2244 -- 37-47 unused -- 2245 inappropriateAuthentication (48), 2246 invalidCredentials (49), 2247 insufficientAccessRights (50), 2248 busy (51), 2249 unavailable (52), 2250 unwillingToPerform (53), 2251 loopDetect (54), 2252 -- 55-63 unused -- 2253 Lightweight Directory Access Protocol Version 3 2255 namingViolation (64), 2256 objectClassViolation (65), 2257 notAllowedOnNonLeaf (66), 2258 notAllowedOnRDN (67), 2259 entryAlreadyExists (68), 2260 objectClassModsProhibited (69), 2261 -- 70 reserved for CLDAP -- 2262 affectsMultipleDSAs (71), 2263 -- 72-79 unused -- 2264 other (80), 2265 ... }, 2266 -- 81-90 reserved for APIs -- 2267 matchedDN LDAPDN, 2268 diagnosticMessage LDAPString, 2269 referral [3] Referral OPTIONAL } 2271 Referral ::= SEQUENCE OF LDAPURL 2273 LDAPURL ::= LDAPString -- limited to characters permitted in 2274 -- URLs 2276 Controls ::= SEQUENCE OF Control 2278 Control ::= SEQUENCE { 2279 controlType LDAPOID, 2280 criticality BOOLEAN DEFAULT FALSE, 2281 controlValue OCTET STRING OPTIONAL } 2283 BindRequest ::= [APPLICATION 0] SEQUENCE { 2284 version INTEGER (1 .. 127), 2285 name LDAPDN, 2286 authentication AuthenticationChoice } 2288 AuthenticationChoice ::= CHOICE { 2289 simple [0] OCTET STRING, 2290 -- 1 and 2 reserved 2291 sasl [3] SaslCredentials, 2292 ... } 2294 SaslCredentials ::= SEQUENCE { 2295 mechanism LDAPString, 2296 credentials OCTET STRING OPTIONAL } 2298 BindResponse ::= [APPLICATION 1] SEQUENCE { 2299 COMPONENTS OF LDAPResult, 2300 serverSaslCreds [7] OCTET STRING OPTIONAL } 2302 UnbindRequest ::= [APPLICATION 2] NULL 2304 SearchRequest ::= [APPLICATION 3] SEQUENCE { 2305 baseObject LDAPDN, 2306 scope ENUMERATED { 2307 baseObject (0), 2308 singleLevel (1), 2309 Lightweight Directory Access Protocol Version 3 2311 wholeSubtree (2) }, 2312 derefAliases ENUMERATED { 2313 neverDerefAliases (0), 2314 derefInSearching (1), 2315 derefFindingBaseObj (2), 2316 derefAlways (3) }, 2317 sizeLimit INTEGER (0 .. maxInt), 2318 timeLimit INTEGER (0 .. maxInt), 2319 typesOnly BOOLEAN, 2320 filter Filter, 2321 attributes AttributeDescriptionList } 2323 Filter ::= CHOICE { 2324 and [0] SET SIZE (1..MAX) OF Filter, 2325 or [1] SET SIZE (1..MAX) OF Filter, 2326 not [2] Filter, 2327 equalityMatch [3] AttributeValueAssertion, 2328 substrings [4] SubstringFilter, 2329 greaterOrEqual [5] AttributeValueAssertion, 2330 lessOrEqual [6] AttributeValueAssertion, 2331 present [7] AttributeDescription, 2332 approxMatch [8] AttributeValueAssertion, 2333 extensibleMatch [9] MatchingRuleAssertion } 2335 SubstringFilter ::= SEQUENCE { 2336 type AttributeDescription, 2337 -- at least one must be present, 2338 -- initial and final can occur at most once 2339 substrings SEQUENCE OF CHOICE { 2340 initial [0] AssertionValue, 2341 any [1] AssertionValue, 2342 final [2] AssertionValue } } 2344 MatchingRuleAssertion ::= SEQUENCE { 2345 matchingRule [1] MatchingRuleId OPTIONAL, 2346 type [2] AttributeDescription OPTIONAL, 2347 matchValue [3] AssertionValue, 2348 dnAttributes [4] BOOLEAN DEFAULT FALSE } 2350 SearchResultEntry ::= [APPLICATION 4] SEQUENCE { 2351 objectName LDAPDN, 2352 attributes PartialAttributeList } 2354 PartialAttributeList ::= SEQUENCE OF SEQUENCE { 2355 type AttributeDescription, 2356 vals SET OF AttributeValue } 2358 SearchResultReference ::= [APPLICATION 19] SEQUENCE OF LDAPURL 2360 SearchResultDone ::= [APPLICATION 5] LDAPResult 2362 ModifyRequest ::= [APPLICATION 6] SEQUENCE { 2363 object LDAPDN, 2364 modification SEQUENCE OF SEQUENCE { 2365 Lightweight Directory Access Protocol Version 3 2367 operation ENUMERATED { 2368 add (0), 2369 delete (1), 2370 replace (2) }, 2371 modification AttributeTypeAndValues } } 2373 AttributeTypeAndValues ::= SEQUENCE { 2374 type AttributeDescription, 2375 vals SET OF AttributeValue } 2377 ModifyResponse ::= [APPLICATION 7] LDAPResult 2379 AddRequest ::= [APPLICATION 8] SEQUENCE { 2380 entry LDAPDN, 2381 attributes AttributeList } 2383 AttributeList ::= SEQUENCE OF SEQUENCE { 2384 type AttributeDescription, 2385 vals SET OF AttributeValue } 2387 AddResponse ::= [APPLICATION 9] LDAPResult 2389 DelRequest ::= [APPLICATION 10] LDAPDN 2391 DelResponse ::= [APPLICATION 11] LDAPResult 2393 ModifyDNRequest ::= [APPLICATION 12] SEQUENCE { 2394 entry LDAPDN, 2395 newrdn RelativeLDAPDN, 2396 deleteoldrdn BOOLEAN, 2397 newSuperior [0] LDAPDN OPTIONAL } 2399 ModifyDNResponse ::= [APPLICATION 13] LDAPResult 2401 CompareRequest ::= [APPLICATION 14] SEQUENCE { 2402 entry LDAPDN, 2403 ava AttributeValueAssertion } 2405 CompareResponse ::= [APPLICATION 15] LDAPResult 2407 AbandonRequest ::= [APPLICATION 16] MessageID 2409 ExtendedRequest ::= [APPLICATION 23] SEQUENCE { 2410 requestName [0] LDAPOID, 2411 requestValue [1] OCTET STRING OPTIONAL } 2413 ExtendedResponse ::= [APPLICATION 24] SEQUENCE { 2414 COMPONENTS OF LDAPResult, 2415 responseName [10] LDAPOID OPTIONAL, 2416 response [11] OCTET STRING OPTIONAL } 2418 END 2419 Lightweight Directory Access Protocol Version 3 2421 Appendix C - Change History 2422 2425 C.1 Changes made to RFC 2251: 2427 C.1.1 Editorial 2429 - Bibliography References: Changed all bibliography references to 2430 use a long name form for readability. 2431 - Changed occurrences of "unsupportedCriticalExtension" 2432 "unavailableCriticalExtension" 2433 - Fixed a small number of misspellings (mostly dropped letters). 2435 C.1.2 Section 1 2437 - Removed IESG note. 2439 C.1.3 Section 9 2441 - Added references to RFCs 1823, 2234, 2829 and 2830. 2443 C.2 Changes made to draft-ietf-ldapbis-protocol-00.txt: 2445 C.2.1 Section 4.1.6 2447 - In the first paragraph, clarified what the contents of an 2448 AttributeValue are. There was confusion regarding whether or not 2449 an AttributeValue that is BER encoded (due to the "binary" option) 2450 is to be wrapped in an extra OCTET STRING. 2451 - To the first paragraph, added wording that doesn't restrict other 2452 transfer encoding specifiers from being used. The previous wording 2453 only allowed for the string encoding and the ;binary encoding. 2454 - To the first paragraph, added a statement restricting multiple 2455 options that specify transfer encoding from being present. This 2456 was never specified in the previous version and was seen as a 2457 potential interoperability problem. 2458 - Added a third paragraph stating that the ;binary option is 2459 currently the only option defined that specifies the transfer 2460 encoding. This is for completeness. 2462 C.2.2 Section 4.1.7 2464 - Generalized the second paragraph to read "If an option specifying 2465 the transfer encoding is present in attributeDesc, the 2466 AssertionValue is encoded as specified by the option...". 2467 Previously, only the ;binary option was mentioned. 2469 C.2.3 Sections 4.2, 4.9, 4.10 2471 - Added alias dereferencing specifications. In the case of modDN, 2472 followed precedent set on other update operations (... alias is 2473 not dereferenced...) In the case of bind and compare stated that 2474 Lightweight Directory Access Protocol Version 3 2476 servers SHOULD NOT dereference aliases. Specifications were added 2477 because they were missing from the previous version and caused 2478 interoperability problems. Concessions were made for bind and 2479 compare (neither should have ever allowed alias dereferencing) by 2480 using SHOULD NOT language, due to the behavior of some existing 2481 implementations. 2483 C.2.4 Sections 4.5 and Appendix A 2485 - Changed SubstringFilter.substrings.initial, any, and all from 2486 LDAPString to AssertionValue. This was causing an incompatibility 2487 with X.500 and confusion among other TS RFCs. 2489 C.3 Changes made to draft-ietf-ldapbis-protocol-01.txt: 2491 C.3.1 Section 3.4 2493 - Reworded text surrounding subschemaSubentry to reflect that it is 2494 a single-valued attribute that holds the schema for the root DSE. 2495 Also noted that if the server masters entries that use differing 2496 schema, each entry's subschemaSubentry attribute must be 2497 interrogated. This may change as further fine-tuning is done to 2498 the data model. 2500 C.3.2 Section 4.1.12 2502 - Specified that the criticality field is only used for requests and 2503 not for unbind or abandon. Noted that it is ignored for all other 2504 operations. 2506 C.3.3 Section 4.2 2508 - Noted that Server behavior is undefined when the name is a null 2509 value, simple authentication is used, and a password is specified. 2511 C.3.4 Section 4.2.(various) 2513 - Changed "unauthenticated" to "anonymous" and "DN" and "LDAPDN" to 2514 "name" 2516 C.3.5 Section 4.2.2 2518 - Changed "there is no authentication or encryption being performed 2519 by a lower layer" to "the underlying transport service cannot 2520 guarantee confidentiality" 2522 C.3.6 Section 4.5.2 2524 - Removed all mention of ExtendedResponse due to lack of 2525 implementation. 2527 C.4 Changes made to draft-ietf-ldapbis-protocol-02.txt: 2529 Lightweight Directory Access Protocol Version 3 2531 C.4.1 Section 4 2533 - Removed "typically" from "and is typically transferred" in the 2534 first paragraph. We know of no (and can conceive of no) case where 2535 this isn't true. 2536 - Added "Section 5.1 specifies how the LDAP protocol is encoded." To 2537 the first paragraph. Added this cross reference for readability. 2538 - Changed "version 3 " to "version 3 or later" in the second 2539 paragraph. This was added to clarify the original intent. 2540 - Changed "protocol version" to "protocol versions" in the third 2541 paragraph. This attribute is multi-valued with the intent of 2542 holding all supported versions, not just one. 2544 C.4.2 Section 4.1.8 2546 - Changed "when transferred in protocol" to "when transferred from 2547 the server to the client" in the first paragraph. This is to 2548 clarify that this behavior only happens when attributes are being 2549 sent from the server. 2551 C.4.3 Section 4.1.10 2553 - Changed "servers will return responses containing fields of type 2554 LDAPResult" to "servers will return responses of LDAPResult or 2555 responses containing the components of LDAPResponse". This 2556 statement was incorrect and at odds with the ASN.1. The fix here 2557 reflects the original intent. 2558 - Dropped '--new' from result codes ASN.1. This simplification in 2559 comments just reduces unneeded verbiage. 2561 C.4.4 Section 4.1.11 2563 - Changed "It contains a reference to another server (or set of 2564 servers)" to "It contains one or more references to one or more 2565 servers or services" in the first paragraph. This reflects the 2566 original intent and clarifies that the URL may point to non-LDAP 2567 services. 2569 C.4.5 Section 4.1.12 2571 - Changed "The server MUST be prepared" to "Implementations MUST be 2572 prepared" in the eighth paragraph to reflect that both client and 2573 server implementations must be able to handle this (as both parse 2574 controls). 2576 C.4.6 Section 4.4 2578 - Changed "One unsolicited notification is defined" to "One 2579 unsolicited notification (Notice of Disconnection) is defined" in 2580 the third paragraph. For clarity and readability. 2582 C.4.7 Section 4.5.1 2583 Lightweight Directory Access Protocol Version 3 2585 - Changed "checking for the existence of the objectClass attribute" 2586 to "checking for the presence of the objectClass attribute" in the 2587 last paragraph. This was done as a measure of consistency (we use 2588 the terms present and presence rather than exists and existence in 2589 search filters). 2591 C.4.8 Section 4.5.3 2593 - Changed "outstanding search operations to different servers," to 2594 "outstanding search operations" in the fifth paragraph as they may 2595 be to the same server. This is a point of clarification. 2597 C.4.9 Section 4.6 2599 - Changed "clients MUST NOT attempt to delete" to "clients MUST NOT 2600 attempt to add or delete" in the second to last paragraph. 2601 - Change "using the "delete" form" to "using the "add" or "delete" 2602 form" in the second to last paragraph. 2604 C.4.10 Section 4.7 2606 - Changed "Clients MUST NOT supply the createTimestamp or 2607 creatorsName attributes, since these will be generated 2608 automatically by the server." to "Clients MUST NOT supply NO-USER- 2609 MODIFICATION attributes such as createTimestamp or creatorsName 2610 attributes, since these are provided by the server." in the 2611 definition of the attributes field. This tightens the language to 2612 reflect the original intent and to not leave a hole in which one 2613 could interpret the two attributes mentioned as the only non- 2614 writable attributes. 2616 C.4.11 Section 4.11 2618 - Changed "has been" to "will be" in the fourth paragraph. This 2619 clarifies that the server will (not has) abandon the operation. 2621 C.5 Changes made to draft-ietf-ldapbis-protocol-03.txt: 2623 C.5.1 Section 3.2.1 2625 - Changed "An attribute is a type with one or more associated 2626 values. The attribute type is identified by a short descriptive 2627 name and an OID (object identifier). The attribute type governs 2628 whether there can be more than one value of an attribute of that 2629 type in an entry, the syntax to which the values must conform, the 2630 kinds of matching which can be performed on values of that 2631 attribute, and other functions." to " An attribute is a 2632 description (a type and zero or more options) with one or more 2633 associated values. The attribute type governs whether the 2634 attribute can have multiple values, the syntax and matching rules 2635 used to construct and compare values of that attribute, and other 2636 functions. Options indicate modes of transfer and other 2637 Lightweight Directory Access Protocol Version 3 2639 functions.". This points out that an attribute consists of both 2640 the type and options. 2642 C.5.2 Section 4 2644 - Changed "Section 5.1 specifies the encoding rules for the LDAP 2645 protocol" to "Section 5.1 specifies how the protocol is encoded 2646 and transferred." 2648 C.5.3 Section 4.1.2 2650 - Added ABNF for the textual representation of LDAPOID. Previously, 2651 there was no formal BNF for this construct. 2653 C.5.4 Section 4.1.4 2655 - Changed "This identifier may be written as decimal digits with 2656 components separated by periods, e.g. "2.5.4.10"" to "may be 2657 written as defined by ldapOID in section 4.1.2" in the second 2658 paragraph. This was done because we now have a formal BNF 2659 definition of an oid. 2661 C.5.5 Section 4.1.5 2663 - Changed the BNF for AttributeDescription to ABNF. This was done 2664 for readability and consistency (no functional changes involved). 2665 - Changed "Options present in an AttributeDescription are never 2666 mutually exclusive." to "Options MAY be mutually exclusive. An 2667 AttributeDescription with mutually exclusive options is treated as 2668 an undefined attribute type." for clarity. It is generally 2669 understood that this is the original intent, but the wording could 2670 be easily misinterpreted. 2671 - Changed "Any option could be associated with any AttributeType, 2672 although not all combinations may be supported by a server." to 2673 "Though any option or set of options could be associated with any 2674 AttributeType, the server support for certain combinations may be 2675 restricted by attribute type, syntaxes, or other factors.". This 2676 is to clarify the meaning of 'combination' (it applies both to 2677 combination of attribute type and options, and combination of 2678 options). It also gives examples of *why* they might be 2679 unsupported. 2681 C.5.6 Section 4.1.11 2683 - Changed the wording regarding 'equally capable' referrals to "If 2684 multiple URLs are present, the client assumes that any URL may be 2685 used to progress the operation.". The previous language implied 2686 that the server MUST enforce rules that it was practically 2687 incapable of. The new language highlights the original intent-- 2688 that is, that any of the referrals may be used to progress the 2689 operation, there is no inherent 'weighting' mechanism. 2691 C.5.7 Section 4.5.1 and Appendix A 2692 Lightweight Directory Access Protocol Version 3 2694 - Added the comment "-- initial and final can occur at most once", 2695 to clarify this restriction. 2697 C.5.8 Section 5.1 2699 - Changed heading from "Mapping Onto BER-based Transport Services" 2700 to "Protocol Encoding". 2702 C.5.9 Section 5.2.1 2704 - Changed "The LDAPMessage PDUs" to "The encoded LDAPMessage PDUs" 2705 to point out that the PDUs are encoded before being streamed to 2706 TCP. 2708 C.6 Changes made to draft-ietf-ldapbis-protocol-04.txt: 2710 C.6.1 Section 4.5.1 and Appendix A 2712 - Changed the ASN.1 for the and and or choices of Filter to have a 2713 lower range of 1. This was an omission in the original ASN.1 2715 C.6.2 Various 2717 - Fixed various typo's 2719 C.7 Changes made to draft-ietf-ldapbis-protocol-05.txt: 2721 C.7.1 Section 3.2.1 2723 - Added "(as defined in Section 12.4.1 of [X.501])" to the fifth 2724 paragraph when talking about "operational attributes". This is 2725 because the term "operational attributes" is never defined. 2726 Alternately, we could drag a definition into the spec, for now, 2727 I'm just pointing to the reference in X.501. 2729 C.7.2 Section 4.1.5 2731 - Changed "And is also case insensitive" to "The entire 2732 AttributeDescription is case insensitive". This is to clarify 2733 whether we're talking about the entire attribute description, or 2734 just the options. 2736 - Expounded on the definition of attribute description options. This 2737 doc now specifies a difference between transfer and tagging 2738 options and describes the semantics of each, and how and when 2739 subtyping rules apply. Now allow options to be transmitted in any 2740 order but disallow any ordering semantics to be implied. These 2741 changes are the result of ongoing input from an engineering team 2742 designed to deal with ambiguity issues surrounding attribute 2743 options. 2745 C.7.3 Sections 4.1.5.1 and 4.1.6 2746 Lightweight Directory Access Protocol Version 3 2748 - Refer to non "binary" transfer encodings as "native encoding" 2749 rather than "string" encoding to clarify and avoid confusion. 2751 C.8 Changes made to draft-ietf-ldapbis-protocol-06.txt: 2753 C.8.1 Title 2755 - Changed to "LDAP: The Protocol" to be consisted with other working 2756 group documents 2758 C.8.2 Abstract 2760 - Moved above TOC to conform to new guidelines 2762 - Reworded to make consistent with other WG documents. 2764 - Moved 2119 conventions to "Conventions" section 2766 C.8.3 Introduction 2768 - Created to conform to new guidelines 2770 C.8.4 Models 2772 - Removed section. There is only one model in this document 2773 (Protocol Model) 2775 C.8.5 Protocol Model 2777 - Removed antiquated paragraph: "In keeping with the goal of easing 2778 the costs associated with use of the directory, it is an objective 2779 of this protocol to minimize the complexity of clients so as to 2780 facilitate widespread deployment of applications capable of using 2781 the directory." 2783 - Removed antiquated paragraph concerning LDAP v1 and v2 and 2784 referrals. 2786 C.8.6 Data Model 2788 - Removed Section 3.2 and subsections. These have been moved to 2789 [Models] 2791 C.8.7 Relationship to X.500 2793 - Removed section. It has been moved to [Roadmap] 2795 C.8.8 Server Specific Data Requirements 2797 - Removed section. It has been moved to [Models] 2799 C.8.9 Elements of Protocol 2800 Lightweight Directory Access Protocol Version 3 2802 - Added "Section 5.1 specifies how the protocol is encoded and 2803 transferred." to the end of the first paragraph for reference. 2805 - Reworded notes about extensibility, and now talk about implied 2806 extensibility and the use of ellipses in the ASN.1 2808 - Removed references to LDAPv2 in third and fourth paragraphs. 2810 C.8.10 Message ID 2812 - Reworded second paragraph to "The message ID of a request MUST 2813 have a non-zero value different from the values of any other 2814 requests outstanding in the LDAP session of which this message is 2815 a part. The zero value is reserved for the unsolicited 2816 notification message." (Added notes about non-zero and the zero 2817 value). 2819 C.8.11 String Types 2821 - Removed ABNF for LDAPOID and added "Although an LDAPOID is encoded 2822 as an OCTET STRING, values are limited to the definition of 2823 numericoid given in Section 1.3 of [Models]." 2825 C.8.12 Distinguished Name and Relative Distinguished Name 2827 - Removed ABNF and referred to [Models] and [LDAPDN] where this is 2828 defined. 2830 C.8.13 Attribute Type 2832 - Removed sections. It's now in the [Models] doc. 2834 C.8.14 Attribute Description 2836 - Removed ABNF and aligned section with [Models] 2838 - Moved AttributeDescriptionList here. 2840 C.8.15 Transfer Options 2842 - Added section and consumed much of old options language (while 2843 aligning with [Models] 2845 C.8.16 Binary Transfer Option 2847 - Clarified intent regarding exactly what is to be BER encoded. 2849 - Clarified that clients must not expect ;binary when not asking for 2850 it (;binary, as opposed to ber encoded data). 2852 C.8.17 Attribute 2854 - Use the term "attribute description" in lieu of "type" 2855 Lightweight Directory Access Protocol Version 3 2857 - Clarified the fact that clients cannot rely on any apparent 2858 ordering of attribute values. 2860 C.8.18 LDAPResult 2862 - To resultCode, added ellipses "..." to the enumeration to indicate 2863 extensibility. and added a note, pointing to [LDAPIANA] 2865 - Removed error groupings ad refer to Appendix A. 2867 C.8.19 Bind Operation 2869 - Added "Prior to the BindRequest, the implied identity is 2870 anonymous. Refer to [AuthMeth] for the authentication-related 2871 semantics of this operation." to the first paragraph. 2873 - Added ellipses "..." to AuthenticationChoice and added a note 2874 "This type is extensible as defined in Section 3.6 of [LDAPIANA]. 2875 Servers that do not support a choice supplied by a client will 2876 return authMethodNotSupported in the result code of the 2877 BindResponse." 2879 - Simplified text regarding how the server handles unknown versions. 2880 Removed references to LDAPv2 2882 C.8.20 Sequencing of the Bind Request 2884 - Aligned with [AuthMeth] In particular, paragraphs 4 and 6 were 2885 removed, while a portion of 4 was retained (see C.8.9) 2887 C.8.21 Authentication and other Security Service 2889 - Section was removed. Now in [AuthMeth] 2891 C.8.22 Continuation References in the Search Result 2893 - Added "If the originating search scope was singleLevel, the scope 2894 part of the URL will be baseObject." 2896 C.8.23 Security Considerations 2898 - Removed reference to LDAPv2 2900 C.8.24 Result Codes 2902 - Added as normative appendix A 2904 C.8.25 ASN.1 2906 - Added EXTENSIBILITY IMPLIED 2908 - Added a number of comments holding referenced to [Models] and 2909 [ISO10646]. 2911 Lightweight Directory Access Protocol Version 3 2913 - Removed AttributeType. It is not used. 2915 C.9 Changes made to draft-ietf-ldapbis-protocol-07.txt: 2917 - Removed all mention of transfer encodings and the binary attribute 2918 option 2920 - Further alignment with [Models]. 2922 - Added extensibility ellipsis to protocol op choice 2924 - In 4.1.1, clarified when connections may be dropped due to 2925 malformed PDUs 2927 - Specified which matching rules and syntaxes are used for various 2928 filter items 2930 C.10 Changes made to draft-ietf-ldapbis-protocol-08.txt: 2932 C.10.1 Section 4.1.1.1: 2934 - Clarified when it is and isn't appropriate to return an already 2935 used message id. 2937 C.10.2 Section 4.1.11: 2939 - Clarified that a control only applies to the message it's attached 2940 to. 2942 - Explained that the criticality field is only applicable to certain 2943 request messages. 2945 - Added language regarding the combination of controls. 2947 C.10.3 Section 4.11: 2949 - Explained that Abandon and Unbind cannot be abandoned, and 2950 illustrated how to determine whether an operation has been 2951 abandoned. 2953 C.11 Changes made to draft-ietf-ldapbis-protocol-09.txt: 2955 - Fixed formatting 2957 C.12 Changes made to draft-ietf-ldapbis-protocol-10.txt: 2959 C.12.1 Section 4.1.4: 2961 - Removed second paragraph as this language exists in MODELS 2962 Lightweight Directory Access Protocol Version 3 2964 C.12.2 Section 4.2.1: 2966 - Replaced fourth paragraph. It was accidentally removed in an 2967 earlier edit. 2969 C.12.2 Section 4.13: 2971 - Added section describing the StartTLS operation (moved from 2972 authmeth) 2974 C.13 Changes made to draft-ietf-ldapbis-protocol-11.txt: 2976 C.13.1 Section 4.1.9 2978 - Changed "errorMessage" to "diagnosticMessage". Simply to indicate 2979 that the field may be non-empty even if a non-error resultCode is 2980 present. 2982 C.13.2 Section 4.2: 2984 - Reconciled language in "name" definition with [AuthMeth] 2986 C.13.3 Section 4.2.1 2988 - Renamed to "Processing of the Bind Request", and moved some text 2989 from 4.2 into this section. 2991 - Rearranged paragraphs to flow better. 2993 - Specified that (as well as failed) an abandoned bind operation 2994 will leave the connection in an anonymous state. 2996 C.13.4 Section 4.5.3 2998 - Generalized the second paragraph which cited indexing and 2999 searchreferralreferences. 3001 C.14 Changes made to draft-ietf-ldapbis-protocol-12.txt: 3003 - Reworked bind errors. 3004 - General clarifications and edits 3006 C.15 Changes made to draft-ietf-ldapbis-protocol-13.txt 3008 C.15.1 Section 2 & various 3009 - Added definitions for LDAP connection, TLS connection, and LDAP 3010 association, and updated appropriate fields to use proper terms. 3012 C.15.2 Section 4.2 3013 - Added text to authentication, specifying the way in which textual 3014 strings used as passwords are to be prepared. 3016 C.15.3 Section 4.5.1 3017 Lightweight Directory Access Protocol Version 3 3019 - Clarified derefInSearching. Specifically how it works in terms of 3020 subtree and one level searches 3022 C.15.4 Section 4.5.2 3024 - Changed MUST to SHOULD for returning textual attribute name, The 3025 MUST is unreasonable. There are likely cases (such as when the 3026 server knows multiple attributes in separate entries of a search 3027 result set share the same short name) where returning a numericoid 3028 is better than returning a short name. That is, the MUST may 3029 actually disallow servers from preventing misinterpretation of 3030 short names. This is not only an interop issue, but likely a 3031 security consideration. 3033 C.15.4 Section 4.9 3034 - Made modify consistent with add in regards to teh need of parent 3035 entries already existing. 3037 C.15.6 Section 4.13.2.2 3038 - Removed wording indicating that referrals can be returned from 3039 StartTLS 3041 Appendix D - Outstanding Work Items 3043 D.0 General 3044 - Integrate notational consistency agreements WG will discuss 3045 notation consistency. Once agreement happens, reconcile draft. 3047 - Reconcile problems with [Models]. Section 3.2 was wholly removed. 3048 There were some protocol semantics in that section that need to be 3049 brought back. Specifically, there was the notion of the server 3050 implicitly adding objectclass superclasses when a value is added. 3052 D.1 Make result code usage consistent. 3054 - While there is a result code appendix, ensure it speaks of result 3055 codes in a general sense, and only highlight specific result codes 3056 in the context of an operation when that operation ties more 3057 specific meanings to that result code. 3059 D.2 Verify references. 3061 - Many referenced documents have changed. Ensure references and 3062 section numbers are correct. 3064 D.3 Usage of Naming Context 3066 - Make sure occurrences of "namingcontext" and "naming context" are 3067 consistent with [Models]. Use in section 6.2 should be reworked. 3068 It's layers of indirection that matter, not number of contexts. 3069 (That is, referrals can be returned for a number of reasons (cross 3070 reference, superior, subordinate, busy, not master, etc.) 3071 Lightweight Directory Access Protocol Version 3 3073 Other uses are fine. 3075 D.4 Review 2119 usage 3077 D.5 Reconcile with I-D Nits 3079 D.23 Section 4.5.3 3081 - A server MUST NOT return any SearchResultReference if it has not 3082 located the baseObject and thus has not searched any entries; in 3083 this case it would return a SearchResultDone containing a referral 3084 resultCode. 3086 - Add "Similarly, a server MUST NOT return a SearchResultReference 3087 when the scope of the search is baseObject. If a client receives 3088 such a SearchResultReference it MUST interpret is as a protocol 3089 error and MUST NOT follow it." to the first paragraph. 3090 The technical specification doesn't have to describe how a 3091 protocol peer should react when its partner violates an absolute. 3093 OR return noSuchObject. 3095 - Add "If the scope part of the LDAP URL is present, the client MUST 3096 use the new scope in its next request to progress the search. If 3097 the scope part is absent the client MUST use subtree scope to 3098 complete subtree searches and base scope to complete one level 3099 searches." to the third paragraph. 3101 D.25 Section 4.6 3103 - Resolve the meaning of "and is ignored if the attribute does not 3104 exist". See "modify: "non-existent attribute"" on the list. Not 3105 sure if there's really an issue here. Will look at archive 3107 D.27 Section 4.10 3109 - Specify what happens when the attr is missing vs. attr isn't in 3110 schema. Also what happens if there's no equality matching rule. 3111 noSuchAttribute, undefinedAttributeType, inappropriateMatching 3113 D.30 Section 5.1 3115 - Add "control and extended operation values" to last paragraph. See 3116 "LBER (BER Restrictions)" on list. 3118 D.32 Section 6.1 3120 - Add "that are used by those attributes" to the first paragraph. 3121 - Add "Servers which support update operations MUST, and other 3122 servers SHOULD, support strong authentication mechanisms described 3123 in [RFC2829]." as a second paragraph. Likely should just say 3124 Lightweight Directory Access Protocol Version 3 3126 Requirements of authentication methods, SASL mechanisms, and TLS 3127 are described in [AUTHMETH]." (also apply to next two below) 3128 - Add "Servers which provide access to sensitive information MUST, 3129 and other servers SHOULD support privacy protections such as those 3130 described in [RFC2829] and [RFC2830]." as a third paragraph. 3132 D.33 Section 7 3134 - Add "Servers which support update operations MUST, and other 3135 servers SHOULD, support strong authentication mechanisms described 3136 in [RFC2829]." as a fourth paragraph. 3137 - Add "In order to automatically follow referrals, clients may need 3138 to hold authentication secrets. This poses significant privacy and 3139 security concerns and SHOULD be avoided." as a sixth paragraph. 3140 There are concerns with "automatic" chasing regardless of which, 3141 if any, authentication method/mechanism is used. 3143 - Add notes regarding DoS attack found by CERT advisories. 3145 D.34 Appendix C 3147 - C.9. Explain why we removed ;binary, and what clients can do to 3148 get around potential problems (likely refer to an I-D) 3149 Lightweight Directory Access Protocol Version 3 3151 Full Copyright Statement 3153 Copyright (C) The Internet Society (2002). All Rights Reserved. 3155 This document and translations of it may be copied and furnished to 3156 others, and derivative works that comment on or otherwise explain it 3157 or assist in its implementation may be prepared, copied, published 3158 and distributed, in whole or in part, without restriction of any 3159 kind, provided that the above copyright notice and this paragraph are 3160 included on all such copies and derivative works. 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