This is a purely informative rendering of an RFC that includes verified errata. This rendering may not be used as a reference.

The following 'Verified' errata have been incorporated in this document: EID 4009, EID 4377
Network Working Group                                             G. Good
Request for Comments: 2849                   iPlanet e-commerce Solutions
Category: Standards Track                                       June 2000


   The LDAP Data Interchange Format (LDIF) - Technical Specification

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

   This document describes a file format suitable for describing
   directory information or modifications made to directory information.
   The file format, known as LDIF, for LDAP Data Interchange Format, is
   typically used to import and export directory information between
   LDAP-based directory servers, or to describe a set of changes which
   are to be applied to a directory.

Background and Intended Usage

   There are a number of situations where a common interchange format is
   desirable.  For example, one might wish to export a copy of the
   contents of a directory server to a file, move that file to a
   different machine, and import the contents into a second directory
   server.

   Additionally, by using a well-defined interchange format, development
   of data import tools from legacy systems is facilitated.  A fairly
   simple set of tools written in awk or perl can, for example, convert
   a database of personnel information into an LDIF file. This file can
   then be imported into a directory server, regardless of the internal
   database representation the target directory server uses.

   The LDIF format was originally developed and used in the University
   of Michigan LDAP implementation.  The first use of LDIF was in
   describing directory entries.  Later, the format was expanded to
   allow representation of changes to directory entries.

   Relationship to the application/directory MIME content-type:

   The application/directory MIME content-type [1] is a general
   framework and format for conveying directory information, and is
   independent of any particular directory service.  The LDIF format is
   a simpler format which is perhaps easier to create, and may also be
   used, as noted, to describe a set of changes to be applied to a
   directory.

   The key words "MUST", "MUST NOT", "MAY", "SHOULD", and "SHOULD NOT"
   used in this document are to be interpreted as described in [7].

Definition of the LDAP Data Interchange Format

   The LDIF format is used to convey directory information, or a
   description of a set of changes made to directory entries.  An LDIF
   file consists of a series of records separated by line separators.  A
   record consists of a sequence of lines describing a directory entry,
   or a sequence of lines describing a set of changes to a directory
   entry.  An LDIF file specifies a set of directory entries, or a set
   of changes to be applied to directory entries, but not both.

   There is a one-to-one correlation between LDAP operations that modify
   the directory (add, delete, modify, and modrdn), and the types of
   changerecords described below ("add", "delete", "modify", and
   "modrdn" or "moddn").  This correspondence is intentional, and
   permits a straightforward translation from LDIF changerecords to
   protocol operations.

Formal Syntax Definition of LDIF

   The following definition uses the augmented Backus-Naur Form
   specified in RFC 2234 [2].

ldif-file                = ldif-content / ldif-changes

ldif-content             = version-spec 1*(1*SEP ldif-attrval-record)

ldif-changes             = version-spec 1*(1*SEP ldif-change-record)

ldif-attrval-record      = dn-spec SEP 1*attrval-spec

ldif-change-record       = dn-spec SEP *control changerecord

version-spec             = "version:" FILL version-number

version-number           = 1*DIGIT
                           ; version-number MUST be "1" for the
                           ; LDIF format described in this document.

dn-spec                  = "dn:" (FILL distinguishedName /
                                  ":" FILL base64-distinguishedName)

distinguishedName        = SAFE-STRING
                           ; a distinguished name, as defined in [3]

base64-distinguishedName = BASE64-UTF8-STRING
                           ; a distinguishedName which has been base64
                           ; encoded (see note 10, below)

rdn                      = SAFE-STRING
                           ; a relative distinguished name, defined as
                           ; <name-component> in [3]

base64-rdn               = BASE64-UTF8-STRING
                           ; an rdn which has been base64 encoded (see
                           ; note 10, below)

control                  = "control:" FILL ldap-oid        ; controlType
                           0*1(1*SPACE ("true" / "false")) ; criticality
                           0*1(value-spec)                ; controlValue
                           SEP
                           ; (See note 9, below)

ldap-oid                 = 1*DIGIT 0*("." 1*DIGIT) 
                           ; An LDAPOID, as defined in [4]
EID 4377 (Verified) is as follows:

Section: LDIF Syntax

Original Text:

ldap-oid                 = 1*DIGIT 0*1("." 1*DIGIT)
                           ; An LDAPOID, as defined in [4]

Corrected Text:

ldap-oid                 = 1*DIGIT 0*("." 1*DIGIT)
                           ; An LDAPOID, as defined in [4]
Notes:
ldap-oid syntax on RFC2849 allow only ONE dot.
But it should allow decimal string separated by multi dots.

RFC2251 LDAPOID definition:
The LDAPOID is a notational convenience to indicate that the
permitted value of this string is a (UTF-8 encoded) dotted-decimal
representation of an OBJECT IDENTIFIER.

LDAPOID ::= OCTET STRING

For example,

1.3.6.1.4.1.1466.1.2.3
attrval-spec = AttributeDescription value-spec SEP value-spec = ":" ( FILL 0*1(SAFE-STRING) / ":" FILL (BASE64-STRING) / "<" FILL url) ; See notes 7 and 8, below url = <a Uniform Resource Locator, as defined in [6]> ; (See Note 6, below) AttributeDescription = AttributeType [";" options] ; Definition taken from [4] AttributeType = ldap-oid / (ALPHA *(attr-type-chars)) options = option / (option ";" options) option = 1*opt-char attr-type-chars = ALPHA / DIGIT / "-" opt-char = attr-type-chars changerecord = "changetype:" FILL (change-add / change-delete / change-modify / change-moddn) change-add = "add" SEP 1*attrval-spec change-delete = "delete" SEP change-moddn = ("modrdn" / "moddn") SEP "newrdn:" ( FILL rdn / ":" FILL base64-rdn) SEP "deleteoldrdn:" FILL ("0" / "1") SEP [8] 0*1("newsuperior:" ( FILL distinguishedName / ":" FILL base64-distinguishedName) SEP) Note 8: If deleteoldrdn is "0" the old rdn will be kept; if it is "1" the old rdn will be deleted.
EID 4009 (Verified) is as follows:

Section: LDIF Syntax

Original Text:

change-moddn             = ("modrdn" / "moddn") SEP
                            "newrdn:" (    FILL rdn /
                                       ":" FILL base64-rdn) SEP
                            "deleteoldrdn:" FILL ("0" / "1")  SEP
                            0*1("newsuperior:"
                            (    FILL distinguishedName /
                             ":" FILL base64-distinguishedName) SEP)

Corrected Text:

change-moddn             = ("modrdn" / "moddn") SEP
                            "newrdn:" (    FILL rdn /
                                       ":" FILL base64-rdn) SEP
                            "deleteoldrdn:" FILL ("0" / "1")  SEP [8]
                            0*1("newsuperior:"
                            (    FILL distinguishedName /
                             ":" FILL base64-distinguishedName) SEP)

Note 8: If deleteoldrdn is "0" the old rdn will be kept; if it is "1"
the old rdn will be deleted.
Notes:
There is no formal specification of the meaning of the "deleteoldrdn" value 0 or 1. 1 stands for deletion, 0 stands for keeping the old rdn. Add a note to explain the value meaning.

-----
Verifier note:
It is correct that the meaning of "deleteoldrdn" is never explained in the document. The proposed resolution is a reasonable fix for that, and such an explanation is needed.
change-modify = "modify" SEP *mod-spec mod-spec = ("add:" / "delete:" / "replace:") FILL AttributeDescription SEP *attrval-spec "-" SEP SPACE = %x20 ; ASCII SP, space FILL = *SPACE SEP = (CR LF / LF) CR = %x0D ; ASCII CR, carriage return LF = %x0A ; ASCII LF, line feed ALPHA = %x41-5A / %x61-7A ; A-Z / a-z DIGIT = %x30-39 ; 0-9 UTF8-1 = %x80-BF UTF8-2 = %xC0-DF UTF8-1 UTF8-3 = %xE0-EF 2UTF8-1 UTF8-4 = %xF0-F7 3UTF8-1 UTF8-5 = %xF8-FB 4UTF8-1 UTF8-6 = %xFC-FD 5UTF8-1 SAFE-CHAR = %x01-09 / %x0B-0C / %x0E-7F ; any value <= 127 decimal except NUL, LF, ; and CR SAFE-INIT-CHAR = %x01-09 / %x0B-0C / %x0E-1F / %x21-39 / %x3B / %x3D-7F ; any value <= 127 except NUL, LF, CR, ; SPACE, colon (":", ASCII 58 decimal) ; and less-than ("<" , ASCII 60 decimal) SAFE-STRING = [SAFE-INIT-CHAR *SAFE-CHAR] UTF8-CHAR = SAFE-CHAR / UTF8-2 / UTF8-3 / UTF8-4 / UTF8-5 / UTF8-6 UTF8-STRING = *UTF8-CHAR BASE64-UTF8-STRING = BASE64-STRING ; MUST be the base64 encoding of a ; UTF8-STRING BASE64-CHAR = %x2B / %x2F / %x30-39 / %x3D / %x41-5A / %x61-7A ; +, /, 0-9, =, A-Z, and a-z ; as specified in [5] BASE64-STRING = [*(BASE64-CHAR)] Notes on LDIF Syntax 1) For the LDIF format described in this document, the version number MUST be "1". If the version number is absent, implementations MAY choose to interpret the contents as an older LDIF file format, supported by the University of Michigan ldap-3.3 implementation [8]. 2) Any non-empty line, including comment lines, in an LDIF file MAY be folded by inserting a line separator (SEP) and a SPACE. Folding MUST NOT occur before the first character of the line. In other words, folding a line into two lines, the first of which is empty, is not permitted. Any line that begins with a single space MUST be treated as a continuation of the previous (non-empty) line. When joining folded lines, exactly one space character at the beginning of each continued line must be discarded. Implementations SHOULD NOT fold lines in the middle of a multi-byte UTF-8 character. 3) Any line that begins with a pound-sign ("#", ASCII 35) is a comment line, and MUST be ignored when parsing an LDIF file. 4) Any dn or rdn that contains characters other than those defined as "SAFE-UTF8-CHAR", or begins with a character other than those defined as "SAFE-INIT-UTF8-CHAR", above, MUST be base-64 encoded. Other values MAY be base-64 encoded. Any value that contains characters other than those defined as "SAFE-CHAR", or begins with a character other than those defined as "SAFE-INIT-CHAR", above, MUST be base-64 encoded. Other values MAY be base-64 encoded. 5) When a zero-length attribute value is to be included directly in an LDIF file, it MUST be represented as AttributeDescription ":" FILL SEP. For example, "seeAlso:" followed by a newline represents a zero-length "seeAlso" attribute value. It is also permissible for the value referred to by a URL to be of zero length. 6) When a URL is specified in an attrval-spec, the following conventions apply: a) Implementations SHOULD support the file:// URL format. The contents of the referenced file are to be included verbatim in the interpreted output of the LDIF file. b) Implementations MAY support other URL formats. The semantics associated with each supported URL will be documented in an associated Applicability Statement. 7) Distinguished names, relative distinguished names, and attribute values of DirectoryString syntax MUST be valid UTF-8 strings. Implementations that read LDIF MAY interpret files in which these entities are stored in some other character set encoding, but implementations MUST NOT generate LDIF content which does not contain valid UTF-8 data. 8) Values or distinguished names that end with SPACE SHOULD be base-64 encoded. 9) When controls are included in an LDIF file, implementations MAY choose to ignore some or all of them. This may be necessary if the changes described in the LDIF file are being sent on an LDAPv2 connection (LDAPv2 does not support controls), or the particular controls are not supported by the remote server. If the criticality of a control is "true", then the implementation MUST either include the control, or MUST NOT send the operation to a remote server. 10) When an attrval-spec, distinguishedName, or rdn is base64- encoded, the encoding rules specified in [5] are used with the following exceptions: a) The requirement that base64 output streams must be represented as lines of no more than 76 characters is removed. Lines in LDIF files may only be folded according to the folding rules described in note 2, above. b) Base64 strings in [5] may contain characters other than those defined in BASE64-CHAR, and are ignored. LDIF does not permit any extraneous characters, other than those used for line folding. Examples of LDAP Data Interchange Format Example 1: An simple LDAP file with two entries version: 1 dn: cn=Barbara Jensen, ou=Product Development, dc=airius, dc=com objectclass: top objectclass: person objectclass: organizationalPerson cn: Barbara Jensen cn: Barbara J Jensen cn: Babs Jensen sn: Jensen uid: bjensen telephonenumber: +1 408 555 1212 description: A big sailing fan. dn: cn=Bjorn Jensen, ou=Accounting, dc=airius, dc=com objectclass: top objectclass: person objectclass: organizationalPerson cn: Bjorn Jensen sn: Jensen telephonenumber: +1 408 555 1212 Example 2: A file containing an entry with a folded attribute value version: 1 dn:cn=Barbara Jensen, ou=Product Development, dc=airius, dc=com objectclass:top objectclass:person objectclass:organizationalPerson cn:Barbara Jensen cn:Barbara J Jensen cn:Babs Jensen sn:Jensen uid:bjensen telephonenumber:+1 408 555 1212 description:Babs is a big sailing fan, and travels extensively in sea rch of perfect sailing conditions. title:Product Manager, Rod and Reel Division Example 3: A file containing a base-64-encoded value version: 1 dn: cn=Gern Jensen, ou=Product Testing, dc=airius, dc=com objectclass: top objectclass: person objectclass: organizationalPerson cn: Gern Jensen cn: Gern O Jensen sn: Jensen uid: gernj telephonenumber: +1 408 555 1212 description:: V2hhdCBhIGNhcmVmdWwgcmVhZGVyIHlvdSBhcmUhICBUaGlzIHZhbHVl IGlzIGJhc2UtNjQtZW5jb2RlZCBiZWNhdXNlIGl0IGhhcyBhIGNvbnRyb2wgY2hhcmFjdG VyIGluIGl0IChhIENSKS4NICBCeSB0aGUgd2F5LCB5b3Ugc2hvdWxkIHJlYWxseSBnZXQg b3V0IG1vcmUu Example 4: A file containing an entries with UTF-8-encoded attribute values, including language tags. Comments indicate the contents of UTF-8-encoded attributes and distinguished names. version: 1 dn:: b3U95Za25qWt6YOoLG89QWlyaXVz # dn:: ou=<JapaneseOU>,o=Airius objectclass: top objectclass: organizationalUnit ou:: 5Za25qWt6YOo # ou:: <JapaneseOU> ou;lang-ja:: 5Za25qWt6YOo # ou;lang-ja:: <JapaneseOU> ou;lang-ja;phonetic:: 44GI44GE44GO44KH44GG44G2 # ou;lang-ja:: <JapaneseOU_in_phonetic_representation> ou;lang-en: Sales description: Japanese office dn:: dWlkPXJvZ2FzYXdhcmEsb3U95Za25qWt6YOoLG89QWlyaXVz # dn:: uid=<uid>,ou=<JapaneseOU>,o=Airius userpassword: {SHA}O3HSv1MusyL4kTjP+HKI5uxuNoM= objectclass: top objectclass: person objectclass: organizationalPerson objectclass: inetOrgPerson uid: rogasawara mail: rogasawara@airius.co.jp givenname;lang-ja:: 44Ot44OJ44OL44O8 # givenname;lang-ja:: <JapaneseGivenname> sn;lang-ja:: 5bCP56yg5Y6f # sn;lang-ja:: <JapaneseSn> cn;lang-ja:: 5bCP56yg5Y6fIOODreODieODi+ODvA== # cn;lang-ja:: <JapaneseCn> title;lang-ja:: 5Za25qWt6YOoIOmDqOmVtw== # title;lang-ja:: <JapaneseTitle> preferredlanguage: ja givenname:: 44Ot44OJ44OL44O8 # givenname:: <JapaneseGivenname> sn:: 5bCP56yg5Y6f # sn:: <JapaneseSn> cn:: 5bCP56yg5Y6fIOODreODieODi+ODvA== # cn:: <JapaneseCn> title:: 5Za25qWt6YOoIOmDqOmVtw== # title:: <JapaneseTitle> givenname;lang-ja;phonetic:: 44KN44Gp44Gr44O8 # givenname;lang-ja;phonetic:: <JapaneseGivenname_in_phonetic_representation_kana> sn;lang-ja;phonetic:: 44GK44GM44GV44KP44KJ # sn;lang-ja;phonetic:: <JapaneseSn_in_phonetic_representation_kana> cn;lang-ja;phonetic:: 44GK44GM44GV44KP44KJIOOCjeOBqeOBq+ODvA== # cn;lang-ja;phonetic:: <JapaneseCn_in_phonetic_representation_kana> title;lang-ja;phonetic:: 44GI44GE44GO44KH44GG44G2IOOBtuOBoeOCh+OBhg== # title;lang-ja;phonetic:: # <JapaneseTitle_in_phonetic_representation_kana> givenname;lang-en: Rodney sn;lang-en: Ogasawara cn;lang-en: Rodney Ogasawara title;lang-en: Sales, Director Example 5: A file containing a reference to an external file version: 1 dn: cn=Horatio Jensen, ou=Product Testing, dc=airius, dc=com objectclass: top objectclass: person objectclass: organizationalPerson cn: Horatio Jensen cn: Horatio N Jensen sn: Jensen uid: hjensen telephonenumber: +1 408 555 1212 jpegphoto:< file:///usr/local/directory/photos/hjensen.jpg Example 6: A file containing a series of change records and comments version: 1 # Add a new entry dn: cn=Fiona Jensen, ou=Marketing, dc=airius, dc=com changetype: add objectclass: top objectclass: person objectclass: organizationalPerson cn: Fiona Jensen sn: Jensen uid: fiona telephonenumber: +1 408 555 1212 jpegphoto:< file:///usr/local/directory/photos/fiona.jpg # Delete an existing entry dn: cn=Robert Jensen, ou=Marketing, dc=airius, dc=com changetype: delete # Modify an entry's relative distinguished name dn: cn=Paul Jensen, ou=Product Development, dc=airius, dc=com changetype: modrdn newrdn: cn=Paula Jensen deleteoldrdn: 1 # Rename an entry and move all of its children to a new location in # the directory tree (only implemented by LDAPv3 servers). dn: ou=PD Accountants, ou=Product Development, dc=airius, dc=com changetype: modrdn newrdn: ou=Product Development Accountants deleteoldrdn: 0 newsuperior: ou=Accounting, dc=airius, dc=com # Modify an entry: add an additional value to the postaladdress # attribute, completely delete the description attribute, replace # the telephonenumber attribute with two values, and delete a specific # value from the facsimiletelephonenumber attribute dn: cn=Paula Jensen, ou=Product Development, dc=airius, dc=com changetype: modify add: postaladdress postaladdress: 123 Anystreet $ Sunnyvale, CA $ 94086 - delete: description - replace: telephonenumber telephonenumber: +1 408 555 1234 telephonenumber: +1 408 555 5678 - delete: facsimiletelephonenumber facsimiletelephonenumber: +1 408 555 9876 - # Modify an entry: replace the postaladdress attribute with an empty # set of values (which will cause the attribute to be removed), and # delete the entire description attribute. Note that the first will # always succeed, while the second will only succeed if at least # one value for the description attribute is present. dn: cn=Ingrid Jensen, ou=Product Support, dc=airius, dc=com changetype: modify replace: postaladdress - delete: description - Example 7: An LDIF file containing a change record with a control version: 1 # Delete an entry. The operation will attach the LDAPv3 # Tree Delete Control defined in [9]. The criticality # field is "true" and the controlValue field is # absent, as required by [9]. dn: ou=Product Development, dc=airius, dc=com control: 1.2.840.113556.1.4.805 true changetype: delete Security Considerations Given typical directory applications, an LDIF file is likely to contain sensitive personal data. Appropriate measures should be taken to protect the privacy of those persons whose data is contained in an LDIF file. Since ":<" directives can cause external content to be included when processing an LDIF file, one should be cautious of accepting LDIF files from external sources. A "trojan" LDIF file could name a file with sensitive contents and cause it to be included in a directory entry, which a hostile entity could read via LDAP. LDIF does not provide any method for carrying authentication information with an LDIF file. Users of LDIF files must take care to verify the integrity of an LDIF file received from an external source. Acknowledgments The LDAP Interchange Format was developed as part of the University of Michigan LDAP reference implementation, and was developed by Tim Howes, Mark Smith, and Gordon Good. It is based in part upon work supported by the National Science Foundation under Grant No. NCR- 9416667. Members of the IETF LDAP Extensions Working group provided many helpful suggestions. In particular, Hallvard B. Furuseth of the University of Oslo made many significant contributions to this document, including a thorough review and rewrite of the BNF. References [1] Howes, T. and M. Smith, "A MIME Content-Type for Directory Information", RFC 2425, September 1998. [2] Crocker, D., and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 2234, November 1997. [3] Wahl, M., Kille, S. and T. Howes, "A String Representation of Distinguished Names", RFC 2253, December 1997. [4] Wahl, M., Howes, T. and S. Kille, "Lightweight Directory Access Protocol (v3)", RFC 2251, July 1997. [5] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996. [6] Berners-Lee, T., Masinter, L. and M. McCahill, "Uniform Resource Locators (URL)", RFC 1738, December 1994. [7] Bradner, S., "Key Words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [8] The SLAPD and SLURPD Administrators Guide. University of Michigan, April 1996. <URL: http://www.umich.edu/~dirsvcs/ldap/doc/guides/slapd/toc.html> [9] M. P. Armijo, "Tree Delete Control", Work in Progress. Author's Address Gordon Good iPlanet e-commerce Solutions 150 Network Circle Mailstop USCA17-201 Santa Clara, CA 95054, USA Phone: +1 408 276 4351 EMail: ggood@netscape.com Full Copyright Statement Copyright (C) The Internet Society (2000). All Rights Reserved. This document and translations of it may be copied and furnished to others, and derivative works that comment on or otherwise explain it or assist in its implementation may be prepared, copied, published and distributed, in whole or in part, without restriction of any kind, provided that the above copyright notice and this paragraph are included on all such copies and derivative works. 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