-
INTERNET-DRAFT Editor: Kurt D. Zeilenga
Intended Category: Standard Track OpenLDAP Foundation
-Expires in six months 15 February 2004
-Obsoletes: 2253
+Expires in six months 10 February 2005
+Obsoletes: RFC 2253
LDAP: String Representation of Distinguished Names
- <draft-ietf-ldapbis-dn-13.txt>
+ <draft-ietf-ldapbis-dn-16.txt>
Status of Memo
- This document is an Internet-Draft and is in full conformance with all
- provisions of Section 10 of RFC2026.
-
This document is intended to be, after appropriate review and
revision, submitted to the RFC Editor as a Standard Track document
replacing RFC 2253. Distribution of this memo is unlimited.
<ietf-ldapbis@openldap.org>. Please send editorial comments directly
to the document editor <Kurt@OpenLDAP.org>.
+ By submitting this Internet-Draft, I accept the provisions of Section
+ 4 of RFC 3667. By submitting this Internet-Draft, I certify that any
+ applicable patent or other IPR claims of which I am aware have been
+ disclosed, or will be disclosed, and any of which I become aware will
+ be disclosed, in accordance with RFC 3668.
+
Internet-Drafts are working documents of the Internet Engineering Task
- Force (IETF), its areas, and its working groups. Note that other
+ Force (IETF), its areas, and its working groups. Note that other
groups may also distribute working documents as Internet-Drafts.
+
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
- time. It is inappropriate to use Internet-Drafts as reference
- material or to cite them other than as ``work in progress.''
+ time. It is inappropriate to use Internet-Drafts as reference material
+ or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
- <http://www.ietf.org/ietf/1id-abstracts.txt>. The list of
- Internet-Draft Shadow Directories can be accessed at
- <http://www.ietf.org/shadow.html>.
-
- Copyright (C) The Internet Society (2004). All Rights Reserved.
-
- Please see the Full Copyright section near the end of this document
- for more information.
-
-
+ http://www.ietf.org/1id-abstracts.html
+ The list of Internet-Draft Shadow Directories can be accessed at
+ http://www.ietf.org/shadow.html
+ Copyright (C) The Internet Society (2005). All Rights Reserved.
+ Please see the Full Copyright section near the end of this document
+ for more information.
Zeilenga LDAP: Distinguished Names [Page 1]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
Abstract
DNs. Comparison of DNs for equality is to be performed in accordance
with the distinguishedNameMatch matching rule [Syntaxes].
- This document is an integral part of the LDAP Technical Specification
- [Roadmap]. This document obsoletes RFC 2253. Changes since RFC 2253
+ This document is a integral part of the LDAP technical specification
+ [Roadmap] which obsoletes the previously defined LDAP technical
Zeilenga LDAP: Distinguished Names [Page 2]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
- are summarized in Appendix B.
+ specification, RFC 3377, in its entirety. This document obsoletes RFC
+ 2253. Changes since RFC 2253 are summarized in Appendix B.
This specification assumes familiarity with X.500 [X.500] and the
concept of Distinguished Name [X.501][Models].
-
Zeilenga LDAP: Distinguished Names [Page 3]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
If the RDNSequence is an empty sequence, the result is the empty or
2.3. Converting AttributeTypeAndValue
The AttributeTypeAndValue is encoded as the string representation of
- the AttributeType, followed by an equals ('=' U+003D) character,
+ the AttributeType, followed by an equals sign ('=' U+003D) character,
followed by the string representation of the AttributeValue. The
encoding of the AttributeValue is given in Section 2.4.
- If the AttributeType is defined to have a short name and that short
- name is known to be registered [REGISTRY][BCP64bis] as identifying the
- AttributeType, that short name, a <descr>, is used. Otherwise the
- AttributeType is encoded as the dotted-decimal encoding, a
- <numericoid>, of its OBJECT IDENTIFIER. The <descr> and <numericoid>
- is defined in [Models].
+ If the AttributeType is defined to have a short name (descriptor)
+ [Models] and that short name is known to be registered
+ [REGISTRY][BCP64bis] as identifying the AttributeType, that short
+ name, a <descr>, is used. Otherwise the AttributeType is encoded as
+ the dotted-decimal encoding, a <numericoid>, of its OBJECT IDENTIFIER.
+ The <descr> and <numericoid> is defined in [Models].
Implementations are not expected to dynamically update their knowledge
of registered short names. However, implementations SHOULD provide a
Zeilenga LDAP: Distinguished Names [Page 4]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
the X.500 AttributeValue. This form is also used when the syntax of
(U+0020, U+0022, U+0023, U+002B, U+002C, U+003B,
U+003C, U+003D, U+003E, U+005C respectively)
- it can be prefixed by a backslash ('\' U+0005C).
+ it can be prefixed by a backslash ('\' U+005C).
Examples of the escaping mechanism are shown in Section 4.
Zeilenga LDAP: Distinguished Names [Page 5]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
Augmented BNF [RFC2234] grammar:
; The following characters are to be escaped when they appear
; in the value to be encoded: ESC, one of <escaped>, leading
; SHARP or SPACE, trailing SPACE, and NULL.
- string = [ (leadchar / pair)
- [ *( stringchar / pair ) ( trailchar / pair ) ] ]
+ string = [ ( leadchar / pair ) [ *( stringchar / pair )
+ ( trailchar / pair ) ] ]
- leadchar = LUTF1 / UTFMB
- LUTF1 = %x01-1F / %x21 / %x24-2A / %x2D-3A /
- %x3D / %x3F-5B / %x5D-7F
+ leadchar = LUTF1 / UTFMB
+ LUTF1 = %x01-1F / %x21 / %x24-2A / %x2D-3A /
+ %x3D / %x3F-5B / %x5D-7F
trailchar = TUTF1 / UTFMB
- TUTF1 = %x01-1F / %x21 / %x23-2A / %x2D-3A /
- %x3D / %x3F-5B / %x5D-7F
+ TUTF1 = %x01-1F / %x21 / %x23-2A / %x2D-3A /
+ %x3D / %x3F-5B / %x5D-7F
stringchar = SUTF1 / UTFMB
- SUTF1 = %x01-21 / %x23-2A / %x2D-3A /
- %x3D / %x3F-5B / %x5D-7F
+ SUTF1 = %x01-21 / %x23-2A / %x2D-3A /
+ %x3D / %x3F-5B / %x5D-7F
- pair = ESC ( ESC / special / hexpair )
- special = escaped / SPACE / SHARP / EQUALS
- escaped = DQUOTE / PLUS / COMMA / SEMI / LANGLE / RANGLE
- hexstring = SHARP 1*hexpair
- hexpair = HEX HEX
+ pair = ESC ( ESC / special / hexpair )
+ special = escaped / SPACE / SHARP / EQUALS
+ escaped = DQUOTE / PLUS / COMMA / SEMI / LANGLE / RANGLE
+ hexstring = SHARP 1*hexpair
+ hexpair = HEX HEX
where the productions <descr>, <numericoid>, <COMMA>, <DQUOTE>,
<EQUALS>, <ESC>, <HEX>, <LANGLE>, <NULL>, <PLUS>, <RANGLE>, <SEMI>,
Zeilenga LDAP: Distinguished Names [Page 6]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
replace <ESC><hexpair> with the octet indicated by the <hexpair>.
Zeilenga LDAP: Distinguished Names [Page 7]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
- This example shows the method of escaping of a comma in a common name:
+ This example shows the method of escaping of a special characters
+ appearing in a common name:
- CN=John Smith\, III,DC=example,DC=net
+ CN=James \"Jim\" Smith\, III,DC=example,DC=net
- An example name in which a value contains a carriage return character:
+ The following shows the method for encoding a value which contains a
+ carriage return character:
CN=Before\0dAfter,DC=example,DC=net
- An example name in which an RDN was of an unrecognized type. The
+ In this RDN example, the type in the RDN is unrecognized, and the
value is the BER encoding of an OCTET STRING containing two octets
0x48 and 0x69.
- 1.3.6.1.4.1.1466.0=#04024869,DC=example,DC=com
+ 1.3.6.1.4.1.1466.0=#04024869
- Finally, an example of an RDN commonName value consisting of 5
- letters:
+ Finally, this example shows an RDN whose commonName value consisting
+ of 5 letters:
Unicode Character Code UTF-8 Escaped
------------------------------- ------ ------ --------
LATIN SMALL LETTER I U+0069 0x69 i
LATIN SMALL LETTER C WITH ACUTE U+0107 0xC487 \C4\87
- could be written in printable ASCII (useful for debugging purposes):
+ could be encoded in printable ASCII (useful for debugging purposes)
+ as:
CN=Lu\C4\8Di\C4\87
other real-world objects. This frequently includes some of the
following kinds of information:
- - the common name of the object (i.e. a person's full name)
- - an email or TCP/IP address
- - its physical location (country, locality, city, street address)
Zeilenga LDAP: Distinguished Names [Page 8]
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+ - the common name of the object (i.e. a person's full name)
+ - an email or TCP/IP address
+ - its physical location (country, locality, city, street address)
- organizational attributes (such as department name or affiliation)
- Most countries have privacy laws regarding the publication of
- information about people.
+ In some cases, such information can be considered sensitive. In many
+ countries, privacy laws exist which prohibit disclosure of certain
+ kinds of descriptive information (e.g., email addresses). Hence,
+ servers implementors are encouraged to support DIT structural rules
+ and name forms [Models] as these provide a mechanism for
+ administrators to select appropriate naming attributes for entries.
+ Administrators are encouraged to use these mechanisms, access
+ controls, and other administrative controls which may be available to
+ restrict use of attributes containing sensitive information in naming
+ of entries. Additionally, use of authentication and data security
+ services in LDAP [AuthMeth][Protocol] should be considered.
5.2. Use of Distinguished Names in Security Applications
Applications which require the reconstruction of the DER form of the
value SHOULD NOT use the string representation of attribute syntaxes
when converting a distinguished name to the LDAP format. Instead,
- they SHOULD use the hexadecimal form prefixed by the number sign ('#')
- as described in the first paragraph of Section 2.3.
+ they SHOULD use the hexadecimal form prefixed by the number sign ('#'
+ U+0023) as described in the first paragraph of Section 2.4.
6. Acknowledgment
This document is a product of the IETF LDAPBIS Working Group.
+
+
+
+Zeilenga LDAP: Distinguished Names [Page 9]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
+
+
7. Document Editor's Address
Kurt D. Zeilenga
OpenLDAP Foundation
- <Kurt@OpenLDAP.org>
+ Email: Kurt@OpenLDAP.org
-8. Normative References
- [X.501] International Telecommunication Union -
- Telecommunication Standardization Sector, "The Directory
- -- Models," X.501(1993) (also ISO/IEC 9594-2:1994).
+8. References
+ [[Note to the RFC Editor: please replace the citation tags used in
+ referencing Internet-Drafts with tags of the form RFCnnnn where
+ possible.]]
-Zeilenga LDAP: Distinguished Names [Page 9]
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+8.1. Normative References
+ [X.501] International Telecommunication Union -
+ Telecommunication Standardization Sector, "The Directory
+ -- Models," X.501(1993) (also ISO/IEC 9594-2:1994).
[X.680] International Telecommunication Union -
Telecommunication Standardization Sector, "Abstract
[RFC2234] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997.
- [RFC3329] Yergeau, F., "UTF-8, a transformation format of ISO
- 10646", RFC 3329 (also STD 64), November 2003.
+ [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
+ 10646", RFC 3629 (also STD 63), November 2003.
[Unicode] The Unicode Consortium, "The Unicode Standard, Version
3.2.0" is defined by "The Unicode Standard, Version 3.0"
progress.
[Roadmap] Zeilenga, K. (editor), "LDAP: Technical Specification
+
+
+
+Zeilenga LDAP: Distinguished Names [Page 10]
+\f
+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
+
+
Road Map", draft-ietf-ldapbis-roadmap-xx.txt, a work in
progress.
[REGISTRY] IANA, Object Identifier Descriptors Registry,
<http://www.iana.org/...>.
-9. Informative References
+8.2. Informative References
[ASCII] Coded Character Set--7-bit American Standard Code for
Information Interchange, ANSI X3.4-1986.
-
-
-
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-
-
[X.500] International Telecommunication Union -
Telecommunication Standardization Sector, "The Directory
-- Overview of concepts, models and services,"
[RFC2849] Good, G., "The LDAP Data Interchange Format (LDIF) -
Technical Specification", RFC 2849, June 2000.
- [BCP64bis] Zeilenga, K., "IANA Considerations for LDAP", draft-
- ietf-ldapbis-bcp64-xx.txt, a work in progress.
+ [BCP64bis] Zeilenga, K., "IANA Considerations for LDAP",
+ draft-ietf-ldapbis-bcp64-xx.txt, a work in progress.
[CharModel] Whistler, K. and M. Davis, "Unicode Technical Report
#17, Character Encoding Model", UTR17,
+
+
+Zeilenga LDAP: Distinguished Names [Page 11]
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+INTERNET-DRAFT draft-ietf-ldapbis-dn-16.txt 10 February 2005
+
+
Appendix A. Presentation Issues
This appendix is provided for informational purposes only, it is not a
Not all user interfaces are capable of displaying the full set of
Unicode characters. Some Unicode characters are not displayable.
-
-
-
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-
-
It is recommended that human interfaces use the optional hex pair
escaping mechanism (Section 2.3) to produce a string representation
suitable for display to the user. For example, an application can
and is to be removed before use in LDAP. For example,
The following DN string is long:
+
+
+
+Zeilenga LDAP: Distinguished Names [Page 12]
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+
+
CN=Kurt D. Zeilenga,OU=Engineering,L=Redwood Shores,
O=OpenLDAP Foundation,ST=California,C=US
so it has been line-wrapped for readability. The extra white
objectClass: person
-
-
-
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-
-
Appendix B. Changes made since RFC 2253
This appendix is provided for informational purposes only, it is not a
- Replaced all references to ISO 10646-1 with [Unicode].
- Clarified (in Section 1) that this document does not define a
canonical string representation.
+ - Clarified that Section 2 describes the RECOMMENDED encoding
+ algorithm and that alternative algorithms are allowed. Some
+ encoding options described in RFC 2253 are now treated as
+ alternative algorithms in this specification.
- Revised specification (in Section 2) to allow short names of any
registered attribute type to appear in string representations of
DNs instead of being restricted to a "published table". Remove
recognition of additional names but require recognization of those
names in the published table. The table is now published in
Section 3.
- - Replaced specification of additional requirements for LDAPv2
- implementations which also support LDAPv3 (RFC 2253, Section 4)
- with a statement (in Section 3) allowing recognition of
- alternative string representations.
- - Updated Section 2.3 to indicate attribute type name strings are
- case insensitive.
+ - Removed specification of additional requirements for LDAPv2
+ implementations which also support LDAPv3 (RFC 2253, Section 4) as
+ LDAPv2 is now Historic.
+ - Allow recognition of alternative string representations.
- Updated Section 2.4 to allow hex pair escaping of all characters
- and clarified escaping for when multiple octet UTF-8 echodings are
- present.
+ and clarified escaping for when multiple octet UTF-8 encodings are
+ present. Indicated that null (U+0000) character is to be escaped.
+
+
+
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+
+
+ Indicated that equals sign ('=' U+003D) character may be escaped
+ as '\='.
- Rewrote Section 3 to use ABNF as defined in RFC 2234.
- - Rewrote Section 3 ABNF to be consistent with 2.4.
+ - Updated the Section 3 ABNF. Changes include:
+ + allow AttributeType short names of length 1 (e.g., 'L'),
+ + use more restrictive <oid> production in AttributeTypes,
+ + do not require escaping of equals sign ('=' U+003D) characters,
+ + do not require escaping of non-leading number sign ('#' U+0023)
+ characters,
+ + allow space (' ' U+0020) to escaped as '\ ',
+ + require hex escaping of null (U+0000) characters, and
+ + removed LDAPv2-only constructs.
- Updated Section 3 to describe how to parse elements of the
grammar.
- Rewrote examples.
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- standards-related documentation can be found in BCP-11. Copies of
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- licenses to be made available, or the result of an attempt made to
- obtain a general license or permission for the use of such proprietary
- rights by implementors or users of this specification can be obtained
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+ INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
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-Full Copyright
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- or as required to translate it into languages other than English.
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