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Date: Tue, 09 Apr 2002 06:01:37 GMT Server: Apache/1.3.20 (Unix) Last-Modified: Wed, 09 Dec 1992 04:34:00 GMT ETag: "3dde03-3e0e-2b257738" Accept-Ranges: bytes Content-Length: 15886 Connection: close Content-Type: text/plain Network Working GroupTimT. HowesINTERNET-DRAFTRequest for Comments: 1488 University of MichiganSteve Hardcastle-Kille University College London WengyikS. Kille ISODE Consortium W. Yeong Performance Systems InternationalColinC. RobbinsX-Tel ServicesNeXor Ltd. July 1993 The X.500 String Representation of Standard Attribute Syntaxes1.Status of this Memo Thisdraft document will be submitted to theRFCEditor as a standards document. Distribution of this memo is unlimited. Please send comments to the authors, or the discussion group <osi-ds@cs.ucl.ac.uk>. This document isspecifies anInternet Draft. Internet Drafts are working docu- ments ofIAB standards track protocol for the InternetEngineering Task Force (IETF), its Areas,community, andits Working Groups. Note that other groups may also distribute working docu- ments as Internet Drafts). Internet Drafts are draft documents validrequests discussion and suggestions fora maximum of six months. Internet Drafts may be updated, replaced, or obsoleted by other docu- ments at any time. It is not appropriate to use Internet Drafts as reference material or to cite them other than as a "working draft" or "work in progress."improvements. Pleasecheck the I-D abstract listing contained in each Internet Draft directoryrefer tolearnthe current edition of the "IAB Official Protocol Standards" for the standardization state and status of thisor any other Internet Draft. 2.protocol. Distribution of this memo is unlimited. Abstract Thelightweight directory protocols requireLightweight Directory Access Protocol (LDAP) [9] requires that the contents ofAttri- buteValueAttributeValue fields in protocol elements be octet strings. This document defines the requirements that must be satisfied by encoding rules used to render Directory attribute syntaxes into a form suitable for use in thelightweight directory protocols,LDAP, then goes on to define the encoding rules for the standard set of attribute syntaxes defined in [1,2] and [3].The attribute syntax encodings defined in this document are adapted from those used in the QUIPU X.500 implementation. The contributions of the authors of the QUIPU implementation in the specification of the QUIPU Expires 2/15/93 [Page 1] Syntax Encoding March 1992 syntaxes [4] are gratefully acknowledged. 3.1. Attribute Syntax EncodingRequirements.Requirements This section defines general requirements for lightweight directorypro- tocolprotocol attribute syntax encodings. All documents defining attributesyn- taxsyntax encodings for use by the lightweight directory protocols are expected to conform to these requirements. The encoding rules defined for a given attribute syntax must produce octet strings. To the greatest extent possible, encoded octet strings should be usable in their native encoded form for display purposes. In particular, encoding rules for attribute syntaxes defining non-binary values should produce strings that can be displayed with little or no translation by clients implementing the lightweight directory protocols.4.Howes, Kille, Yeong & Robbins [Page 1] RFC 1488 X.500 Syntax Encoding July 1993 2. Standard Attribute Syntax Encodings For the purposes of defining the encoding rules for the standardattri- buteattribute syntaxes, the following auxiliary BNF definitions will be used: <a> ::= 'a' | 'b' | 'c' | 'd' | 'e' | 'f' | 'g' | 'h' | 'i' | 'j' | 'k' | 'l' | 'm' | 'n' | 'o' | 'p' | 'q' | 'r' | 's' | 't' | 'u' | 'v' | 'w' | 'x' | 'y' | 'z' | 'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'G' | 'H' | 'I' | 'J' | 'K' | 'L' | 'M' | 'N' | 'O' | 'P' | 'Q' | 'R' | 'S' | 'T' | 'U' | 'V' | 'W' | 'X' | 'Y' | 'Z' <d> ::= '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' <hex-digit> ::= <d> | 'a' | 'b' | 'c' | 'd' | 'e' | 'f' | 'A' | 'B' | 'C' | 'D' | 'E' | 'F' <k> ::= <a> | <d> | '-' <p> ::= <a> | <d> | ''' | '(' | ')' | '+' | ',' | '-' | '.' | '/' | ':' | '?' | ' ' <CRLF> ::= The ASCII newline character with hexadecimal value 0x0A <letterstring> ::= <a> | <a> <letterstring> <numericstring> ::= <d> | <d> <numericstring> <keystring> ::= <a> | <a> <anhstring> <anhstring> ::= <k> | <k><keystring><anhstring> <printablestring> ::= <p> | <p> <printablestring>Expires 2/15/93 [Page 2] Syntax Encoding March 1992<space> ::= ' ' | ' ' <space>4.1.2.1. Undefined Values of type Undefined are encoded as if they were values of type Octet String.4.2.2.2. Case Ignore String A string of type caseIgnoreStringSyntax is encoded as the string value itself.4.3.Howes, Kille, Yeong & Robbins [Page 2] RFC 1488 X.500 Syntax Encoding July 1993 2.3. Case Exact String The encoding of a string of type caseExactStringSyntax is the string value itself.4.4.2.4. Printable String The encoding of a string of type printableStringSyntax is the string value itself.4.5.2.5. Numeric String The encoding of a string of type numericStringSyntax is the string value itself.4.6.2.6. Octet String The encoding of a string of type octetStringSyntax is the string value itself.4.7.2.7. Case Ignore IA5 String The encoding of a string of type caseIgnoreIA5String is the string value itself.4.8.2.8. IA5 String The encoding of a string of type iA5StringSyntax is the string value itself.4.9.2.9. T61 String The encoding of a string of type t61StringSyntax is the string value itself.Expires 2/15/93 [Page 3] Syntax Encoding March 1992 4.10.2.10. Case Ignore List Values of type caseIgnoreListSyntax are encoded according to thefollow- ingfollowing BNF: <caseignorelist> ::= <caseignorestring> | <caseignorestring> '$' <caseignorelist> <caseignorestring> ::= a string encoded according to the rules for Case Ignore String as above.4.11.Howes, Kille, Yeong & Robbins [Page 3] RFC 1488 X.500 Syntax Encoding July 1993 2.11. Case Exact List Values of type caseExactListSyntax are encoded according to thefollow- ingfollowing BNF: <caseexactlist> ::= <caseexactstring> | <caseexactstring> '$' <caseexactlist> <caseexactstring> ::= a string encoded according to the rules for Case Exact String as above.4.12.2.12. Distinguished Name Values of type distinguishedNameSyntax are encoded to have therepresen- tationrepresentation defined in [5].4.13.2.13. Boolean Values of type booleanSyntax are encoded according to the following BNF: <boolean> ::= "TRUE" | "FALSE" Boolean values have an encoding of "TRUE" if they are logically true, and have an encoding of "FALSE" otherwise.4.14.2.14. Integer Values of type integerSyntax are encoded as the decimal representation of their values, with each decimal digit represented by the itscharac- tercharacter equivalent. So the digit 1 is represented by the character'1', the digit 2 is represented by the character '2' and so on. 4.15.2.15. Object Identifier Values of type objectIdentifierSyntax are encoded according to theExpires 2/15/93 [Page 4] Syntax Encoding March 1992following BNF: <oid> ::= <descr> | <descr> '.' <numericoid> | <numericoid> <descr> ::= <keystring> <numericoid> ::= <numericstring> | <numericstring> '.' <numericoid> In the above BNF, <descr> is the syntactic representation of an object descriptor. When encoding values of type objectIdentifierSyntax, the first encoding option should be used in preference to the second, which should be used in preference to the Howes, Kille, Yeong & Robbins [Page 4] RFC 1488 X.500 Syntax Encoding July 1993 third wherever possible. That is, in encoding object identifiers, object descriptors (where assigned and known by the implementation) should be used in preference to numeric oids to the greatest extent possible. For example, in encoding the object identifier representing an organizationName, the descriptor``organizationName''"organizationName" is preferable to``ds.4.10'',"ds.4.10", which is in turn preferable to the string``2.5.4.10''. 4.16."2.5.4.10". 2.16. Telephone Number Values of type telephoneNumberSyntax are encoded as if they werePrint- ablePrintable String types.4.17.2.17. Telex Number Values of type telexNumberSyntax are encoded according to the following BNF: <telex-number> ::= <actual-number> '$' <country> '$' <answerback> <actual-number> ::= <printablestring> <country> ::= <printablestring> <answerback> ::= <printablestring> In the above, <actual-number> is the syntactic representation of the number portion of the TELEX number being encoded, <country> is the TELEX country code, and <answerback> is the answerback code of a TELEX terminal.4.18.2.18. Teletex Terminal Identifier Values of type teletexTerminalIdentifier are encoded according to the following BNF: <teletex-id> ::= <printablestring> 0*( '$' <printablestring>)Expires 2/15/93 [Page 5] Syntax Encoding March 1992In the above, the first <printablestring> is the encoding of the first portion of the teletex terminal identifier to be encoded, and thesubse- quentsubsequent 0 or more <printablestrings> are subsequent portions of the teletex terminal identifier.4.19.2.19. Facsimile Telephone Number Values of type FacsimileTelephoneNumber are encoded according to the following BNF: <fax-number> ::= <printablestring> [ '$' <faxparameters> ] Howes, Kille, Yeong & Robbins [Page 5] RFC 1488 X.500 Syntax Encoding July 1993 <faxparameters> ::= <faxparm> | <faxparm> '$' <faxparameters> <faxparm> ::= 'twoDimensional' | 'fineResolution' | 'unlimitedLength' | 'b4Length' | 'a3Width' | 'b4Width' | 'uncompressed' In the above, the first <printablestring> is the actual fax number, and the <faxparm> tokens represent fax parameters.4.20.2.20. Presentation Address Values of type PresentationAddress are encoded to have therepresenta- tionrepresentation described in [6].4.21.2.21. UTC Time Values of type uTCTimeSyntax are encoded as if they were Printable Strings with the strings containing a UTCTime value.4.22.2.22. Guide (search guide) Values of type Guide, such as values of the searchGuide attribute, are encoded according to the following BNF: <guide-value> ::= [ <object-class> '#' ] <criteria> <object-class> ::= an encoded value of type objectIdentifierSyntax <criteria> ::= <criteria-item> | <criteria-set> | '!' <criteria> <criteria-set> ::= [ '(' ] <criteria> '&' <criteria-set> [ ')' ] | [ '(' ] <criteria> '|' <criteria-set> [ ')' ] <criteria-item> ::= [ '(' ] <attributetype> '$' <match-type> [ ')' ] <match-type> ::= "EQ" | "SUBSTR" | "GE" | "LE" | "APPROX"Expires 2/15/93 [Page 6] Syntax Encoding March 1992 4.23.2.23. Postal Address Values of type PostalAddress are encoded according to the following BNF: <postal-address> ::= <t61string> | <t61string> '$' <postal-address> In the above, each <t61string> component of a postal address value is encoded as a value of type t61StringSyntax.4.24.Howes, Kille, Yeong & Robbins [Page 6] RFC 1488 X.500 Syntax Encoding July 1993 2.24. User Password Values of type userPasswordSyntax are encoded as if they were of type octetStringSyntax.4.25.2.25. User Certificate Values of type userCertificate are encoded according to the following BNF: <certificate> ::= <signature> '#' <issuer> '#' <validity> '#' <subject> '#' <public-key-info> <signature> ::= <algorithm-id> <issuer> ::= an encoded Distinguished Name <validity> ::= <not-before-time> '#' <not-after-time> <not-before-time> ::= <utc-time> <not-after-time> ::= <utc-time> <algorithm-parameters> ::= <null> | <integervalue> | '{ASN}' <hex-string> <subject> ::= an encoded Distinguished Name <public-key-info> ::= <algorithm-id> '#' <encrypted-value> <encrypted-value> ::= <hex-string> | <hex-string> '-' <d> <algorithm-id> ::= <oid> '#' <algorithm-parameters> <utc-time> ::= an encoded UTCTime value <hex-string> ::= <hex-digit> | <hex-digit> <hex-string>Expires 2/15/93 [Page 7] Syntax Encoding March 1992 4.26.2.26. CA Certificate Values of type cACertificate are encoded as if the values were of type userCertificate.4.27.2.27. Authority Revocation List Values of type authorityRevocationList are encoded according to thefol- lowingfollowing BNF: Howes, Kille, Yeong & Robbins [Page 7] RFC 1488 X.500 Syntax Encoding July 1993 <certificate-list> ::= <signature> '#' <issuer> '#' <utc-time> [ '#' <revoked-certificates> ] <revoked-certificates> ::= <algorithm> '#' <encrypted-value> [ '#' 0*(<revoked-certificate>) '#'] <revoked-certificates> ::= <subject> '#' <algorithm> '#' <serial> '#' <utc-time> The syntactic components <algorithm>, <issuer>, <encrypted-value>, <utc-time>, <subject> and <serial> have the same definitions as in the BNF for the userCertificate attribute syntax.4.28.2.28. Certificate Revocation List Values of type certificateRevocationList are encoded as if the values were of type authorityRevocationList.4.29.2.29. Cross Certificate Pair Values of type crossCertificatePair are encoded according to thefollow- ingfollowing BNF: <certificate-pair> ::= <certificate> '|' <certificate> The syntactic component <certificate> has the same definition as in the BNF for the userCertificate attribute syntax.4.30.2.30. Delivery Method Values of type deliveryMethod are encoded according to the following BNF: <delivery-value> ::= <pdm> | <pdm> '$' <delivery-value> <pdm> ::= 'any' | 'mhs' | 'physical' | 'telex' | 'teletex' | 'g3fax' | 'g4fax' | 'ia5' | 'videotex' | 'telephone'Expires 2/15/93 [Page 8] Syntax Encoding March 1992 4.31.2.31. Other Mailbox Values of the type otherMailboxSyntax are encoded according to thefol- lowingfollowing BNF: <otherMailbox> ::= <mailbox-type> '$' <mailbox> <mailbox-type> ::= an encoded Printable String <mailbox> ::= an encoded IA5 String Howes, Kille, Yeong & Robbins [Page 8] RFC 1488 X.500 Syntax Encoding July 1993 In the above, <mailbox-type> represents the type of mail system in which the mailbox resides, for example "Internet" or "MCIMail"; and <mailbox> is the actual mailbox in the mail system defined by <mailbox-type>.4.32.2.32. Mail Preference Values of type mailPreferenceOption are encoded according to thefollow- ingfollowing BNF: <mail-preference> ::= "NO-LISTS" | "ANY-LIST" | "PROFESSIONAL-LISTS"4.33.2.33. MHS OR Address Values of type MHS OR Address are encoded as strings, according to the format defined in [10]. 2.34. Photo Values of type Photo are encoded as if they were octet stringscontain- ingcontaining JPEG images in the JPEG File Interchange Format(JFIF). 4.34.(JFIF), as described in [8]. 2.35. Fax Values of type Fax are encoded as if they were octet strings containing Group 3 Faximages. 5. Security Considerations Security considerations are not discussedimages as defined in [7]. 3. Acknowledgements Many of the attribute syntax encodings defined in thisdocument. 6.document are adapted from those used in the QUIPU X.500 implementation. The contribu- tions of the authors of the QUIPU implementation in the specification of the QUIPU syntaxes [4] are gratefully acknowledged. 4. Bibliography [1] The Directory: Selected AttributeSyntaxes CCITT;Syntaxes. CCITT, RecommendationX.520X.520. [2] Information Processing Systems -- Open Systems Interconnection -- The Directory: Selected AttributeSyntaxesSyntaxes. [3]TheBarker, P., and S. Kille, "The COSINE and Internet X.500Schema Paul Barker, Steve Hardcastle-Kille; Request for Comment (RFC) 1274 Expires 2/15/93 [Page 9] Syntax Encoding March 1992Schema", RFC 1274, University College London, November 1991. [4] The ISO Development Environment: User's Manual -- Volume 5:QUIPUQUIPU. Colin Robbins, Stephen E.Hardcastle-KilleKille. Howes, Kille, Yeong & Robbins [Page 9] RFC 1488 X.500 Syntax Encoding July 1993 [5]AKille, S., "A String Representation of DistinguishedNames Steve Hardcastle-Kille; OSI-DS document 23Names", RFC 1485, July 1993. [6]AKille, S., "A String Representation for PresentationAddresses Steve Hardcastle-Kille; RequestAddresses", RFC 1278, University College London, November 1991. [7] Terminal Equipment and Protocols for Telematic Services - Standardization of Group 3 facsimile apparatus forComment (RFC) 1278 Expires 2/15/93document transmission. CCITT, Recommendation T.4. [8] JPEG File Interchange Format (Version 1.02). Eric Hamilton, C- Cube Microsystems, Milpitas, CA, September 1, 1992. [9] Yeong, W., Howes, T., and S. Kille, "Lightweight Directory Access Protocol", RFC 1487, Performance Systems International, University of Michigan, ISODE Consortium, July 1993. [10] Kille, S., "Mapping between X.400(1988)/ISO 10021 and RFC 822", RFC 1327, University College London, May 1992. 5. Security Considerations Security issues are not discussed in this memo. Howes, Kille, Yeong & Robbins [Page 10] RFC 1488 X.500 Syntax Encoding July 1993 6. Authors' Addresses Tim Howes University of Michigan ITD Research Systems 535 W William St. Ann Arbor, MI 48103-4943 USA Phone: +1 313 747-4454 EMail: tim@umich.edu Steve Kille ISODE Consortium PO Box 505 London SW11 1DX UK Phone: +44-71-223-4062 EMail: S.Kille@isode.com Wengyik Yeong PSI, Inc. 510 Huntmar Park Drive Herndon, VA 22070 USA Phone: +1 703-450-8001 EMail: yeongw@psilink.com Colin Robbins NeXor Ltd University Park Nottingham NG7 2RD UK Howes, Kille, Yeong & Robbins [Page 11] ----