draft-ietf-ldapbis-dn-00.txt   draft-ietf-ldapbis-dn-01.txt 
INTERNET-DRAFT Editor: Kurt D. Zeilenga INTERNET-DRAFT Editor: Kurt D. Zeilenga
Intended Category: Standard Track OpenLDAP Foundation Intended Category: Standard Track OpenLDAP Foundation
Expires: 20 May 2001 20 December 2000 Expires: 26 August 2001 26 February 2001
Obsoletes: 1779, 2253 Obsoletes: 2253
Lightweight Directory Access Protocol (v3): Lightweight Directory Access Protocol (v3):
UTF-8 String Representation of Distinguished Names UTF-8 String Representation of Distinguished Names
<draft-ietf-ldapbis-dn-00.txt> <draft-ietf-ldapbis-dn-01.txt>
Status of Memo Status of Memo
This document is an Internet-Draft and is in full conformance with all This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026. provisions of Section 10 of RFC2026.
This document is intended to be, after appropriate review and This document is intended to be, after appropriate review and
revision, submitted to the RFC Editor as a Standard Track document revision, submitted to the RFC Editor as a Standard Track document
replacing RFC 1779 and RFC 2253. Distribution of this memo is replacing RFC 2253. Distribution of this memo is unlimited.
unlimited. Technical discussion of this document will take place on Technical discussion of this document will take place on the IETF LDAP
the IETF LDAP Revision Working Group (LDAPbis) mailing list Revision Working Group (LDAPbis) mailing list
<ietf-ldapbis@openldap.org>. Please send editorial comments directly <ietf-ldapbis@openldap.org>. Please send editorial comments directly
to the document editor <Kurt@OpenLDAP.org>. to the document editor <Kurt@OpenLDAP.org>.
Internet-Drafts are working documents of the Internet Engineering Task 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. groups may also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as ``work in progress.'' material or to cite them other than as ``work in progress.''
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft 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. Shadow Directories can be accessed at http://www.ietf.org/shadow.html.
Copyright 2000, The Internet Society. All Rights Reserved. Copyright 2001, The Internet Society. All Rights Reserved.
Please see the Copyright section near the end of this document for Please see the Copyright section near the end of this document for
more information. more information.
Abstract Abstract
The X.500 Directory uses distinguished names as the primary keys to The X.500 Directory uses distinguished names as the primary keys to
entries in the directory. Distinguished Names are encoded in ASN.1 in entries in the directory. Distinguished Names are encoded in ASN.1 in
the X.500 Directory protocols. In the Lightweight Directory Access the X.500 Directory protocols. In the Lightweight Directory Access
Protocol, a string representation of distinguished names is Protocol, a string representation of distinguished names is
transferred. This specification defines the string format for transferred. This specification defines the string format for
representing names, which is designed to give a clean representation representing names, which is designed to give a clean representation
of commonly used distinguished names, while being able to represent of commonly used distinguished names, while being able to represent
any distinguished name. any distinguished name.
This document obsoletes RFC 2253.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
1. Background 1. Background
This specification assumes familiarity with X.500 [X.500], and the This specification assumes familiarity with X.500 [X.500], and the
concept of Distinguished Name. It is important to have a common concept of Distinguished Name (DN). It is important to have a common
format to be able to unambiguously represent a distinguished name. format to be able to unambiguously represent a distinguished name.
The primary goal of this specification is ease of encoding and The primary goal of this specification is ease of encoding and
decoding. A secondary goal is to have names that are human readable. decoding. A secondary goal is to have names that are human readable.
It is not expected that LDAP clients with a human user interface would It is not expected that LDAP clients with a human user interface would
display these strings directly to the user, but would most likely be display these strings directly to the user, but would most likely be
performing translations (such as expressing attribute type names in performing translations (such as expressing attribute type names in
one of the local national languages). one of the local national languages).
2. Converting DistinguishedName from ASN.1 to a String 2. Converting DistinguishedName from ASN.1 to a String
skipping to change at page 3, line 31 skipping to change at page 3, line 33
character. character.
2.3. Converting AttributeTypeAndValue 2.3. Converting AttributeTypeAndValue
The AttributeTypeAndValue is encoded as the string representation of The AttributeTypeAndValue is encoded as the string representation of
the AttributeType, followed by an equals character ('=' ASCII 61), the AttributeType, followed by an equals character ('=' ASCII 61),
followed by the string representation of the AttributeValue. The followed by the string representation of the AttributeValue. The
encoding of the AttributeValue is given in section 2.4. encoding of the AttributeValue is given in section 2.4.
If the AttributeType is in the following table of attribute types If the AttributeType is in the following table of attribute types
associated with LDAP [RFC2252], then the type name string from that associated with LDAP [RFC2252bis], then the type name string from that
table is used, otherwise it is encoded as the dotted-decimal encoding table is used, otherwise it is encoded as the dotted-decimal encoding
of the AttributeType's OBJECT IDENTIFIER. The dotted-decimal notation of the AttributeType's OBJECT IDENTIFIER. The dotted-decimal notation
is described in [RFC2251]. is described in [RFC2251bis].
The type name string is not case sensitive.
String X.500 AttributeType String X.500 AttributeType
------------------------------ ------ ----------------------
CN commonName CN commonName
L localityName L localityName
ST stateOrProvinceName ST stateOrProvinceName
O organizationName O organizationName
OU organizationalUnitName OU organizationalUnitName
C countryName C countryName
STREET streetAddress STREET streetAddress
DC domainComponent DC domainComponent
UID userId UID userId
skipping to change at page 4, line 14 skipping to change at page 4, line 18
If the AttributeValue is of a type which does not have a string If the AttributeValue is of a type which does not have a string
representation defined for it, then it is simply encoded as an representation defined for it, then it is simply encoded as an
octothorpe character ('#' ASCII 35) followed by the hexadecimal octothorpe character ('#' ASCII 35) followed by the hexadecimal
representation of each of the octets of the BER encoding of the X.500 representation of each of the octets of the BER encoding of the X.500
AttributeValue. This form SHOULD be used if the AttributeType is of AttributeValue. This form SHOULD be used if the AttributeType is of
the dotted-decimal form. the dotted-decimal form.
Otherwise, if the AttributeValue is of a type which has a string Otherwise, if the AttributeValue is of a type which has a string
representation, the value is converted first to a UTF-8 string representation, the value is converted first to a UTF-8 string
according to its syntax specification (see for example section 6 of according to its syntax specification (see for example section 6 of
[RFC2252]). [RFC2252bis]).
If the UTF-8 string does not have any of the following characters If the UTF-8 string does not have any of the following characters
which need escaping, then that string can be used as the string which need escaping, then that string can be used as the string
representation of the value. representation of the value.
- a space or "#" character occurring at the beginning of the string - a space (' ' ASCII 32) or octothorpe ('#' ASCII 35) occurring at the
beginning of the string
- a space character occurring at the end of the string - a space (' ' ASCII 32) character occurring at the end of the string
- one of the characters ",", "+", """, "\", "<", ">" or ";" - one of the characters ",", "+", """, "\", "<", ">" or ";" (ASCII 44,
43, 34, 92, 60, 62, or 59, respectively)
Implementations MAY escape other characters. Implementations MAY escape other characters.
Each octet of the character to be escaped is replaced by a backslash Each octet of the character to be escaped is replaced by a backslash
and two hex digits, which form a single octet in the code of the and two hex digits, which form a single octet in the code of the
character. Alternatively, if and only if the character to be escaped character. Alternatively, if and only if the character to be escaped
is one of is one of
",", "+", """, "\", "<", ">", ";", "#", "=", or " " ",", "+", """, "\", "<", ">", ";", "#", "=", or " "
(ASCII 44, 43, 34, 92, 60, 62, 59, 35, or 32, respectively)
it may be prefixed by a backslash ('\' ASCII 92). it may be prefixed by a backslash ('\' ASCII 92).
Examples of the escaping mechanism are shown in section 4. Examples of the escaping mechanism are shown in section 4.
3. Parsing a String back to a Distinguished Name 3. Parsing a String back to a Distinguished Name
The structure of the UTF-8 string is specified using the following The structure of the UTF-8 string is specified using the following
Augmented BNF [RFC2234] grammar. Augmented BNF [RFC2234] grammar.
skipping to change at page 6, line 7 skipping to change at page 6, line 15
SHARP = %x23 ; sharp sign ("#") SHARP = %x23 ; sharp sign ("#")
PLUS = %x2B ; plus sign ("+") PLUS = %x2B ; plus sign ("+")
COMMA = %x2C ; comma (",") COMMA = %x2C ; comma (",")
MINUS = %x2D ; minus sign ("-") MINUS = %x2D ; minus sign ("-")
DOT = %x2E ; period (".") DOT = %x2E ; period (".")
EQUALS = %x3D ; equals sign ("=") EQUALS = %x3D ; equals sign ("=")
ESC = %x5C ; backslash ("\") ESC = %x5C ; backslash ("\")
4. Examples 4. Examples
This notation is designed to be convenient for common forms of This notation is designed to be convenient for common forms of name.
name. This section gives a few examples of distinguished names This section gives a few examples of distinguished names written using
written using this notation. First is a name containing three this notation. First is a name containing three relative
relative distinguished names (RDNs): distinguished names (RDNs):
UID=jsmith,DC=example,DC=net UID=jsmith,DC=example,DC=net
Here is an example name containing three RDNs, in which the first Here is an example name containing three RDNs, in which the first RDN
RDN is multi-valued: is multi-valued:
OU=Sales+CN=J. Smith,DC=example,DC=net OU=Sales+CN=J. Smith,DC=example,DC=net
This example shows the method of quoting of a comma in a common This example shows the method of quoting of a comma in a common name:
name:
CN=John Smith\, III,DC=example,DC=net CN=John Smith\, III,DC=example,DC=net
An example name in which a value contains a carriage return An example name in which a value contains a carriage return character:
character:
CN=Before\0dAfter,DC=example,DC=net CN=Before\0dAfter,DC=example,DC=net
An example name in which an RDN was of an unrecognized type. The An example name in which an RDN was of an unrecognized type. The
value is the BER encoding of an OCTET STRING containing two octets value is the BER encoding of an OCTET STRING containing two octets
0x48 and 0x69. 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,DC=example,DC=com
Finally, an example of an RDN commonName value consisting of 5 Finally, an example of an RDN commonName value consisting of 5
letters: letters:
Unicode Letter Description 10646 code UTF-8 Quoted Unicode Letter Description 10646 code UTF-8 Quoted
=============================== ========== ====== ======= =============================== ========== ====== =======
LATIN CAPITAL LETTER L U0000004C 0x4C L LATIN CAPITAL LETTER L U0000004C 0x4C L
LATIN SMALL LETTER U U00000075 0x75 u LATIN SMALL LETTER U U00000075 0x75 u
LATIN SMALL LETTER C WITH CARON U0000010D 0xC48D \C4\8D LATIN SMALL LETTER C WITH CARON U0000010D 0xC48D \C4\8D
LATIN SMALL LETTER I U00000069 0x69 i LATIN SMALL LETTER I U00000069 0x69 i
LATIN SMALL LETTER C WITH ACUTE U00000107 0xC487 \C4\87 LATIN SMALL LETTER C WITH ACUTE U00000107 0xC487 \C4\87
Could be written in printable ASCII (useful for debugging purposes): could be written in printable ASCII (useful for debugging purposes):
CN=Lu\C4\8Di\C4\87 CN=Lu\C4\8Di\C4\87
5. Security Considerations 5. Security Considerations
The following security considerations are specific to the handling of The following security considerations are specific to the handling of
distinguished names. For security considerations specific to LDAP, distinguished names. LDAP security considerations are discussed in
see RFC 2251, RFC 2829, and RFC 2830. [RFC2251bis] and its normative references.
5.1. Disclosure 5.1. Disclosure
Distinguished Names typically consist of descriptive information about Distinguished Names typically consist of descriptive information about
the entries they name, which can be people, organizations, devices or the entries they name, which can be people, organizations, devices or
other real-world objects. This frequently includes some of the other real-world objects. This frequently includes some of the
following kinds of information: following kinds of information:
- the common name of the object (i.e. a person's full name) - the common name of the object (i.e. a person's full name)
- an email or TCP/IP address - an email or TCP/IP address
skipping to change at page 7, line 46 skipping to change at page 8, line 9
representation CN=Sam. representation CN=Sam.
Applications which require the reconstruction of the DER form of the Applications which require the reconstruction of the DER form of the
value SHOULD NOT use the string representation of attribute syntaxes value SHOULD NOT use the string representation of attribute syntaxes
when converting a distinguished name to the LDAP format. Instead, when converting a distinguished name to the LDAP format. Instead,
they SHOULD use the hexadecimal form prefixed by the octothorpe ('#') they SHOULD use the hexadecimal form prefixed by the octothorpe ('#')
as described in the first paragraph of section 2.4. as described in the first paragraph of section 2.4.
6. References 6. References
[X.500] The Directory -- overview of concepts, models and services. [X.500] "The Directory -- overview of concepts, models and
ITU-T Rec. X.500(1993). services," ITU-T Rec. X.500(1993).
[X.501] The Directory -- Models. ITU-T Rec. X.501(1993). [X.501] "The Directory -- Models," ITU-T Rec. X.501(1993).
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119. Requirement Levels", RFC 2119.
[RFC2234] Crocker, D., and P. Overell, "Augmented BNF for Syntax [RFC2234] Crocker, D., and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997. Specifications: ABNF", RFC 2234, November 1997.
[RFC2247] S. Kille, M. Wahl, A. Grimstad, R. Huber, S. Sataluri, [RFC2279] Yergeau, F., "UTF-8, a transformation format of ISO
"Using Domains in LDAP/X.500 Distinguished Names", RFC 2247, 10646", RFC 2279, January 1998.
January 1998.
[RFC2279] Yergeau, F., "UTF-8, a transformation format of ISO 10646", [RFC2251bis] LDAPbis WG, "Lightweight Directory Access Protocol (v3)",
RFC 2279, January 1998. a work in progress.
[RFC2251] Wahl, M., Howes, T., and S. Kille, "Lightweight Directory [RFC2252bis] LDAPbis WG, "LDAPv3: Attribute Syntax Definitions", a
Access Protocol (v3)", RFC 2251, December 1997. work in progress.
[RFC2252] Wahl, M., Coulbeck, A., Howes, T. and S. Kille, "Lightweight [RFC2256bis] LDAPbis WG, "LDAPv3: User Schema", a work in progress.
Directory Access Protocol (v3): Attribute Syntax
Definitions", RFC 2252, December 1997.
7. Acknowledgment 7. Acknowledgment
This document is an update to RFC 2253, by Mark Wahl, Tim Howes, and This document is an update to RFC 2253, by Mark Wahl, Tim Howes, and
Steve Kille. Design ideas included in this revised specification are Steve Kille. RFC 2253 was a product of the IETF ASID Working Group.
based upon those discussed in LDAP Revision (proposed) Working Group
(LDAPbis) and other IETF Working Groups. The contributions of This document is a product of the IETF LDAPbis Working Group.
individuals in these working groups is gratefully acknowledged.
8. Document Editor's Address 8. Document Editor's Address
Kurt D. Zeilenga Kurt D. Zeilenga
OpenLDAP Foundation OpenLDAP Foundation
<Kurt@OpenLDAP.org> <Kurt@OpenLDAP.org>
Appendix A. Changes made to RFC 2253 Appendix A. Changes made to RFC 2253
[Editor's Note: this non-normative appendix may be removed prior to [Editor's Note: this non-normative appendix may be removed prior to
skipping to change at page 8, line 45 skipping to change at page 9, line 4
8. Document Editor's Address 8. Document Editor's Address
Kurt D. Zeilenga Kurt D. Zeilenga
OpenLDAP Foundation OpenLDAP Foundation
<Kurt@OpenLDAP.org> <Kurt@OpenLDAP.org>
Appendix A. Changes made to RFC 2253 Appendix A. Changes made to RFC 2253
[Editor's Note: this non-normative appendix may be removed prior to [Editor's Note: this non-normative appendix may be removed prior to
publication as an RFC] publication as an RFC]
The following substantive changes were made to RFC 2253: The following substantive changes were made to RFC 2253:
- Removed IESG Note - Removed IESG Note
- Removed specification of additional requirements for LDAPv2 - Removed specification of additional requirements for LDAPv2
implementations which also support LDAPv3 (Section 4). implementations which also support LDAPv3 (Section 4).
- Updated 2.3 to clarify which table is the published table of names - Updated 2.3 to clarify which table is the published table of names
which may be appear in DNs. Remove "as an example" language. which may be appear in DNs. Remove "as an example" language. -
Updated 2.3 to indicate attribute type name strings are not case
sensitive.
- Updated 2.4 to allow hex pair escaping of all characters and - Updated 2.4 to allow hex pair escaping of all characters and
clarified escaping for when multiple octet UTF-8 characters are clarified escaping for when multiple octet UTF-8 characters are
present. present.
- Rewrote Section 3 to use ABNF as defined in RFC 2234. - Rewrote Section 3 to use ABNF as defined in RFC 2234.
- Rewrote Section 3 ABNF to be consistent with 2.4. - Rewrote Section 3 ABNF to be consistent with 2.4.
- Rewrote examples - Rewrote examples
- Added reference to documentations containing LDAP-specific - Added reference to documentations containing LDAP-specific
security considerations security considerations.
In addition, numerous editorial changes were made. In addition, numerous editorial changes were made.
Copyright 2000, The Internet Society. All Rights Reserved. Copyright 2001, The Internet Society. All Rights Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published and or assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind, distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of Internet organizations, except as needed for the purpose of
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/