MIME Directory Profile for LDAP Schema
draft-ietf-schema-ldap-01

Network Working Group                                            M. Wahl
Request for Comments: DRAFT                 Innosoft International, Inc.
                                                          August 1, 1998

                  MIME Directory Profile for LDAP Schema
                     <draft-ietf-schema-ldap-01.txt>

1. Status of this Memo

   This document is an Internet-Draft.  Internet-Drafts are working docu-
   ments of the Internet Engineering Task 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.''
 
   To view the entire list of current Internet-Drafts, please check
   the "1id-abstracts.txt" listing contained in the Internet-Drafts
   Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net
   (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au
   (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu.

2. Abstract

   This document defines a MIME directory profile [1] for holding an
   LDAP [2] schema.  It is intended for communication with the Internet
   schema listing service.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in 
   this document are to be interpreted as described in RFC 2119 [4].

3. Overview

   This document defines how a MIME type may be used to transfer a 
   single LDAPv3 schema definition.  

   A schema for use with LDAPv3 consists of any number of object class, 
   attribute type, matching rule and syntax definitions.  These concepts
   are defined in the LDAPv3 protocol definition [2].  The schema MAY
   have a numeric OID assigned to it by a schema listing or registration 
   service.

   A schema may import definitions from another schema.  Schema imports
   are not, however, transitive.

   For example, a schema contains a definition for a "modem" object 
   class, which is to be defined as a subclass of the X.521 "device" 
   object class.  In this case, the schema MUST import the definitions 
   of X.521.

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4. The "schema-ldap-0" MIME Directory Profile Registration
   
   This profile is identified by the following registration template 
   information.

   To: ietf-mime-direct@imc.org

   Subject: Registration of text/directory MIME profile "schema-ldap-0"

   Profile name: schema-ldap-0

   Profile purpose: To represent a schema defined for use with 
    LDAPv3 servers.

   Profile types: SOURCE, ldapSchemas, attributeTypes,
    matchingRules, objectClasses, matchingRuleUse, ldapSyntaxes

   Profile special notes:

    The charset parameter MUST be present on the MIME content, and
    the value of this parameter MUST be "utf-8".  This ensures that 
    schema values can be used in LDAPv3 attribute values without a 
    character set translation.

    Neither the "BEGIN" and "END" types nor type grouping are used 
    in contents of this profile.

    All of the types in this profile with the exception of ldapSchemas
    may be multi-valued.  Each value is present on its own contentline. 
    Values may be present in any order, and need not be arranged by type.

    The "SOURCE" type is optional, and if values are present they SHOULD
    be URIs of the "ldap" form.  If the URI is of the "ldap" form, the 
    object indicated by the URI is a subschema entry.  The use of other
    forms are reserved for future applications.

    In this version of the profile, exactly one value of the ldapSchemas
    type MUST be present.  (Later versions of the profile may permit
    multiple ldapSchemas values to be present in a content.)

    Implementors should note that there will likely be values of the 
    profile types in most contents much longer than 76 bytes.  In
    addition, there may be non-ASCII characters and embedded CRLFs
    inside of values, which could require either quoting of the value or
    use of a content transfer encoding.  

    If a contentline in a particular content contains a "context" 
    parameter and the value of that parameter is not "ldap", then that
    contentline SHOULD be ignored.

   Intended usage: COMMON

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5. MIME Directory Type Registrations

   This document defines all the types, with the exception of "SOURCE"
   used in the schema-ldap-0 profile.  The "SOURCE" type is defined in
   [1].  These types are primarily intended for use in the 
   "schema-ldap-0" directory profile, although they may be applicable 
   to other profiles defined in the future.

5.1. ldapSchemas

   To: ietf-mime-direct@imc.org
   Subject: Registration of text/directory MIME type ldapSchemas
   
   Type name: ldapSchemas

   Type purpose: To represent the LDAPv3 attribute "ldapSchemas",
    defined in section A.1.

   Type encoding: 8bit

   Type valuetype: text, encoded according to the BNF of section A.4.

   Type special notes: Each value of this type specifies the contents of
    an LDAP schema definition.  A definition of each object class, 
    attribute, matching rule, matching rule use and syntax referenced in
    a value of ldapSchemas MUST either be defined in one of the schemas 
    referenced in the "IMPORTS" field, or present in the content 
    containing this value. 

   Intended usage: COMMON

5.2. attributeTypes

   To: ietf-mime-direct@imc.org
   Subject: Registration of text/directory MIME type attributeTypes
   
   Type name: attributeTypes

   Type purpose: To represent the LDAPv3 attribute "attributeTypes", 
   defined in section 5.1.6 of [4].

   Type encoding: 8bit

   Type valuetype: text, encoded according to the BNF of
   "AttributeTypeDescription" given in section 4.2 of [4].

   Type special notes: Each value of the type specifies one LDAPv3 
    attribute type definition.  The syntax and matching rules 
    referenced in a value of attributeTypes MUST either be present in 
    this content, or defined in one of the schemas referenced in the 
    "IMPORTS" field of the ldapSchemas line.

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   Intended usage: COMMON

5.3. matchingRules

   To: ietf-mime-direct@imc.org
   Subject: Registration of text/directory MIME type matchingRules
   
   Type name: matchingRules

   Type purpose: To represent the LDAPv3 attribute "matchingRules",
   defined in section 5.1.8 of [4].

   Type encoding: 8bit

   Type valuetype: text, encoded according to the BNF of
   "MatchingRuleDescription" given in section 4.5 of [4].

   Type special notes: Each value of the type specifies one matching rule
    definition.  The syntax reference in a value of matchingRules MUST 
    either be present in this content, or defined in one of the schemas 
    referenced in the "IMPORTS" field of the ldapSchemas line.

   Intended usage: COMMON

5.4. objectClasses

   To: ietf-mime-direct@imc.org
   Subject: Registration of text/directory MIME type objectClasses
   
   Type name: objectClasses

   Type purpose: To represent the LDAPv3 attribute "objectClasses",
   defined in section 5.1.7 of [4].

   Type encoding: 8bit

   Type valuetype: text, encoded according to the BNF of
   "ObjectClassDescription" given in section 4.4 of [4].

   Type special notes: Each value of the type specifies one LDAPv3 
    object class definition.  The attributes and object classes 
    referenced in a value of objectClasses MUST either be present in 
    this content, or defined in one of the schema referenced in the 
    "IMPORTS" field of the ldapSchemas line.

   Intended usage: COMMON

5.5. matchingRuleUse

   To: ietf-mime-direct@imc.org
   Subject: Registration of text/directory MIME type matchingRuleUse
   
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   Type name: matchingRuleUse

   Type purpose: To represent the LDAPv3 attribute "matchingRuleUse",
   defined in section 5.1.9 of [4].

   Type encoding: 8bit

   Type valuetype: text, encoded according to the BNF of
   "MatchingRuleUseDescription" given in section 4.5 of [4].

   Type special notes: Each value of the type specifies a relationship
    between a matching rule and attribute types.  The matching rule and 
    attribute types referenced in a value of matchingRuleUse MUST either
    be present in this content, or defined in one of the schemas
    referenced in the "IMPORTS" statement of the ldapSchemas line.

   Intended usage: COMMON

5.6. ldapSyntaxes

   To: ietf-mime-direct@imc.org
   Subject: Registration of text/directory MIME type ldapSyntaxes
   
   Type name: ldapSyntaxes

   Type purpose: To represent the LDAPv3 attribute "ldapSyntaxes",
   defined in section 5.3.1 of [3].

   Type encoding: 8bit

   Type valuetype: text, encoded according to the BNF of
   "SyntaxDescription" given in section 4.3.3 of [3].

   Type special notes: Each value of this type specifies a single LDAPv3
    attribute value syntax.

   Intended usage: COMMON

6. Example

   From: Whomever@wherever.com
   To: Someone@somewhere.com
   Subject: schema information
   MIME-Version: 1.0
   Message-Id: <ids1@wherever.com>
   Content-Type: text/directory; profile="schema-ldap-0";charset="utf-8"
   Content-Transfer-Encoding: Quoted-Printable
   

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   ldapSchemas: ( 1.2.3.4 NAME 'bogus schema' CLASSES ( top $ thing ) =
   ATTRIBUTES ( objectClass $ name ) SYNTAXES ( =
   1.3.6.1.4.1.1466.115.121.1.38 $ 1.3.6.1.4.1.1466.115.121.1.15 ) )
   attributeTypes: ( 2.5.4.0 NAME 'objectClass' SYNTAX =
   1.3.6.1.4.1.1466.115.121.1.38 )
   objectClasses: ( 2.5.6.0 NAME 'top' ABSTRACT MUST objectClass )
   attributeTypes: ( 2.5.4.41 NAME 'name' SYNTAX =
   1.3.6.1.4.1.1466.115.121.1.15{32768} )
   objectClasses: ( 2.5.6.999 NAME 'thing' MUST name )
   ldapSyntaxes: ( 1.3.6.1.4.1.1466.115.121.1.15 DESC 'String' )
   ldapSyntaxes: ( 1.3.6.1.4.1.1466.115.121.1.38 DESC 'OID' )

7. Security Considerations
 
   A MIME body part containing an text/directory of the schema-ldap-0 
   profile may be incorporated in a digitally signed MIME content, which
   can be used to verify that the body part has not been modified in 
   transit.  When the signer has been certified by a trusted third party
   service, it may also be possible to verify the origin of the content.

8. Bibliography

   [1] "A MIME Content-Type for Directory Information", 07/24/1997, 
       INTERNET DRAFT <draft-ietf-asid-mime-direct-04.txt>.

   [2] "Lightweight Directory Access Protocol (v3)", Dec. 1997,
       RFC 2251.

   [3] "Lightweight Directory Access Protocol (v3):  Attribute Syntax 
       Definitions", Dec. 1997, RFC 2252.

   [4] S. Bradner, "Key words for use in RFCs to Indicate Requirement
       Levels", RFC 2119.

9. Authors Address

       Mark Wahl
       Innosoft International, Inc.
       8911 Capital of Texas Hwy Suite 4140
       Austin, TX 78759
       USA

       EMail:  M.Wahl@innosoft.com

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Appendix A

   This appendix defines two new attributes which could be present in 
   an subschema entry.  These attributes could be added to a future 
   revision of the LDAP attribute definition [3].

A.1. ldapSchemas attribute type definition

     ( 1.3.6.1.4.1.1466.101.120.17 NAME 'ldapSchemas' 
       SYNTAX 1.3.6.1.4.1.1466.115.121.1.56 USAGE directoryOperation )

   Each value of the ldapSchemas attribute defines one schema.  Its
   syntax, given in section A.2, contains the elements needed for an 
   LDAPv3 server to correctly process operations which use the 
   definitions from this syntax.

A.2. LDAP Schema Definition syntax definition

     ( 1.3.6.1.4.1.1466.115.121.1.56 DESC 'LDAP Schema Definition' )

   Values in this syntax are represented according to the following BNF:

     LdapSchema = "(" whsp
       numericoid whsp
       [ "NAME" qdescrs ]
       [ "OBSOLETE" whsp ]
       [ "IMPORTS" oids ]
       [ "CLASSES" oids ]
       [ "ATTRIBUTES" oids ]
       [ "MATCHING-RULES" oids ]
       [ "SYNTAXES" oids ]
       whsp ")"

   The numericoid field uniquely identifies the schema.  A new OID 
   should be assigned if any of the fields of the schema change.  It is 
   not possible to import definitions from a schema until an OID has 
   been assigned to it.

   The "NAME" field contains optional human-readable labels for the 
   schema.

   The "OBSOLETE" field is present if the schema is obsolete.  

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   The "IMPORTS" field lists the OIDs of other schemas which are to be
   incorporated by reference into this schema.  It is an error to have
   an attribute type or object class defined in a schema with the same
   name but a different OID as an attribute type or object class in an
   imported schema.  It is also an error to import from two schema
   definitions in which there are attribute types or object classes
   with the same names but different OIDs.

   The "CLASSES" field lists the OIDs of object classes defined in this 
   schema.  A schema need not contain any object class definitions.  A 
   schema must not contain two object class definitions of the same name
   but with different OIDs.

   The "ATTRIBUTES" field lists the OIDs of attribute types defined in 
   this schema.  A schema need not contain any object class definitions.
   A schema must not contain two attribute type definitions of the same 
   name but with different OIDs.

   The "MATCHING-RULES" field lists the OIDs of matching rules defined 
   in this schema.  A schema need not contain any matching rules.

   The "SYNTAXES" field lists the OIDs of syntaxes defined in this 
   schema. A schema need not contain any syntaxes.

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