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Versions: 00                                                            
Network Working Group                                        Tim Howes
INTERNET-DRAFT                                  University of Michigan
                                                           Steve Kille
                                                      ISODE Consortium
                                                         Wengyik Yeong
                                     Performance Systems International
                                                         Colin Robbins
                                                            NeXor Ltd.
                                                             Mark Wahl
                                                      ISODE Consortium


        The String Representation of Standard Attribute Syntaxes
               <draft-ietf-asid-ldapv2-attributes-00.txt>


1.  Status of this Memo

This draft document will be submitted to the RFC Editor 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 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 learn the current status of any Internet-Draft, please check the
``1id-abstracts.txt'' listing contained in the Internet- Drafts Shadow
Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe),
ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim).

2.  Abstract

The Lightweight Directory Access Protocol (LDAP) [9] requires that the
contents of AttributeValue fields in protocol elements be octet strings.
This document defines the requirements that must be satisfied by encod-
ing rules used to render X.500 Directory attribute syntaxes into a form
suitable for use in the LDAP, then goes on to define the encoding rules
for the standard set of attribute syntaxes defined in [1,2] and [3].






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3.  Attribute Syntax Encoding Requirements.

This section defines general requirements for lightweight directory pro-
tocol attribute syntax encodings. All documents defining attribute syn-
tax 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.  Table of LDAP Attributes

This section lists all Attribute Type names defined for this version of
LDAP.  Servers may support additional names and attributes not listed
here by bilateral agreement.

4.1.  Standard User Attributes

The attributes listed in this section are those defined in X.520(1988),
likely to be present in user entries.

    Attribute Type Name             OID             Syntax
    ====================            =============== ================
    objectClass                     2.5.4.0         OID
    aliasedObjectName               2.5.4.1         DN
    knowledgeInformation            2.5.4.2         caseIgnoreString
    cn                              2.5.4.3         caseIgnoreString
    sn                              2.5.4.4         caseIgnoreString
    serialNumber                    2.5.4.5         PrintableString
    c                               2.5.4.6         CountryString
    l                               2.5.4.7         caseIgnoreString
    st                              2.5.4.8         caseIgnoreString
    street                          2.5.4.9         caseIgnoreString
    o                               2.5.4.10        caseIgnoreString
    ou                              2.5.4.11        caseIgnoreString
    title                           2.5.4.12        caseIgnoreString
    description                     2.5.4.13        caseIgnoreString
    searchGuide                     2.5.4.14        Guide
    businessCategory                2.5.4.15        caseIgnoreString
    postalAddress                   2.5.4.16        PostalAddress
    postalCode                      2.5.4.17        caseIgnoreString
    postOfficeBox                   2.5.4.18        caseIgnoreString
    physicalDeliveryOfficeName      2.5.4.19        caseIgnoreString
    telephoneNumber                 2.5.4.20        TelephoneNumber



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    telexNumber                     2.5.4.21        TelexNumber
    teletexTerminalIdentifier       2.5.4.22        TeletexTerminalIdentifier
    facsimileTelephoneNumber        2.5.4.23        FacsimileTelephoneNumber
    x121Address                     2.5.4.24        NumericString
    internationaliSDNNumber         2.5.4.25        NumericString
    registeredAddress               2.5.4.26        PostalAddress
    destinationIndicator            2.5.4.27        PrintableString
    preferredDeliveryMethod         2.5.4.28        DeliveryMethod
    presentationAddress             2.5.4.29        PresentationAddress
    supportedApplicationContext     2.5.4.30        OID
    member                          2.5.4.31        DN
    owner                           2.5.4.32        DN
    roleOccupant                    2.5.4.33        DN
    seeAlso                         2.5.4.34        DN
    userPassword                    2.5.4.35        Password
    userCertificate                 2.5.4.36        Certificate
    cACertificate                   2.5.4.37        Certificate
    authorityRevocationList         2.5.4.38        CertificateList
    certificateRevocationList       2.5.4.39        CertificateList
    crossCertificatePair            2.5.4.40        CertificatePair


4.2.  Pilot User Attributes

These attributes are defined in RFC 1274.

    Attribute Type Name     OID                             Syntax
    ====================    =============================== ================
    uid                     0.9.2342.19200300.100.1.1       CaseIgnoreString
    textEncodedORaddress    0.9.2342.19200300.100.1.2       CaseIgnoreString
    mail                    0.9.2342.19200300.100.1.3       CaseIgnoreIA5String
    info                    0.9.2342.19200300.100.1.4       CaseIgnoreString
    drink                   0.9.2342.19200300.100.1.5       CaseIgnoreString
    roomNumber              0.9.2342.19200300.100.1.6       CaseIgnoreString
    photo                   0.9.2342.19200300.100.1.7       Fax
    userClass               0.9.2342.19200300.100.1.8       CaseIgnoreString
    host                    0.9.2342.19200300.100.1.9       CaseIgnoreString
    manager                 0.9.2342.19200300.100.1.10      DN
    documentIdentifier      0.9.2342.19200300.100.1.11      CaseIgnoreString
    documentTitle           0.9.2342.19200300.100.1.12      CaseIgnoreString
    documentVersion         0.9.2342.19200300.100.1.13      CaseIgnoreString
    documentAuthor          0.9.2342.19200300.100.1.14      DN
    documentLocation        0.9.2342.19200300.100.1.15      CaseIgnoreString
    homePhone               0.9.2342.19200300.100.1.20      TelephoneNumber
    secretary               0.9.2342.19200300.100.1.21      DN
    otherMailbox            0.9.2342.19200300.100.1.22      OtherMailbox
    lastModifiedTime        0.9.2342.19200300.100.1.23      UTCTime
    lastModifiedBy          0.9.2342.19200300.100.1.24      DN



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    dc                      0.9.2342.19200300.100.1.25      CaseIgnoreIA5String
    dNSRecord               0.9.2342.19200300.100.1.26      IA5String
    mXRecord                0.9.2342.19200300.100.1.28      IA5String
    nSRecord                0.9.2342.19200300.100.1.29      IA5String
    sOARecord               0.9.2342.19200300.100.1.30      IA5String
    cNAMERecord             0.9.2342.19200300.100.1.31      IA5String
    associatedDomain        0.9.2342.19200300.100.1.37      CaseIgnoreIA5String
    associatedName          0.9.2342.19200300.100.1.38      DN
    homePostalAddress       0.9.2342.19200300.100.1.39      PostalAddress
    personalTitle           0.9.2342.19200300.100.1.40      CaseIgnoreString
    mobile                  0.9.2342.19200300.100.1.41      TelephoneNumber
    pager                   0.9.2342.19200300.100.1.42      TelephoneNumber
    co                      0.9.2342.19200300.100.1.43      CaseIgnoreString
    organizationalStatus    0.9.2342.19200300.100.1.45      CaseIgnoreString
    janetMailbox            0.9.2342.19200300.100.1.46      CaseIgnoreIA5String
    mailPreferenceOption    0.9.2342.19200300.100.1.47      MailPreference
    buildingName            0.9.2342.19200300.100.1.48      CaseIgnoreString
    personalSignature       0.9.2342.19200300.100.1.53      Fax
    dITRedirect             0.9.2342.19200300.100.1.54      DN
    audio                   0.9.2342.19200300.100.1.55      Audio
    documentPublisher       0.9.2342.19200300.100.1.56      CaseIgnoreString
    jpegPhoto               0.9.2342.19200300.100.1.60      JPEG

5.  Standard Attribute Syntax Encodings

For the purposes of defining the encoding rules for the standard attri-
bute 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>



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     <numericstring> ::= <d> | <d> <numericstring>

     <keystring> ::= <a> | <a> <anhstring>

     <anhstring> ::= <k> | <k> <anhstring>

     <printablestring> ::= <p> | <p> <printablestring>

     <space> ::= ' ' | ' ' <space>


5.1.  Undefined

This syntax is to be used for any values whose syntax is not defined by
another section of this document.  Values of type Undefined are encoded
as if they were values of type Octet String, with the string value being
the BER-encoded version of the value.

5.2.  Case Ignore String

A string of type caseIgnoreStringSyntax is encoded as the string value
itself.

5.3.  Case Exact String

The encoding of a string of type caseExactStringSyntax is the string
value itself.

5.4.  Printable String

The encoding of a string of type printableStringSyntax is the string
value itself.

5.5.  Numeric String

The encoding of a string of type numericStringSyntax is the string value
itself.

5.6.  Octet String

The encoding of a string of type octetStringSyntax is the string value
itself.

5.7.  Case Ignore IA5 String

The encoding of a string of type caseIgnoreIA5String is the string value
itself.




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5.8.  IA5 String

The encoding of a string of type iA5StringSyntax is the string value
itself.

5.9.  T61 String

The encoding of a string of type t61StringSyntax is the string value
itself.

5.10.  Case Ignore List

Values of type caseIgnoreListSyntax are encoded according to the follow-
ing BNF:

     <caseignorelist> ::= <caseignorestring> |
                          <caseignorestring> '$' <caseignorelist>

     <caseignorestring> ::= a string encoded according to the rules for Case
                             Ignore String as above.


5.11.  Case Exact List

Values of type caseExactListSyntax are encoded according to the follow-
ing BNF:

     <caseexactlist> ::= <caseexactstring> |
                          <caseexactstring> '$' <caseexactlist>

     <caseexactstring> ::= a string encoded according to the rules for Case
                           Exact String as above.


5.12.  Distinguished Name

Values of type distinguishedNameSyntax are encoded to have the represen-
tation defined in [5].

5.13.  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.




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5.14.  Integer

Values of type integerSyntax are encoded as the decimal representation
of their values, with each decimal digit represented by the its charac-
ter equivalent. So the digit 1 is represented by the character '1', the
digit 2 is represented by the character '2' and so on.

5.15.  Object Identifier

Values of type objectIdentifierSyntax are encoded according to the fol-
lowing 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 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'' is preferable to ``ds.4.10'', which is in turn
preferable to the string ``2.5.4.10''.

5.16.  Telephone Number

Values of type telephoneNumberSyntax are encoded as if they were Print-
able String types.

5.17.  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



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portion of the TELEX number being encoded, <country> is the TELEX
country code, and <answerback> is the answerback code of a TELEX terminal.

5.18.  Teletex Terminal Identifier

Values of type teletexTerminalIdentifier are encoded according to the
following BNF:

     <teletex-id> ::= <printablestring>  0*('$' <ttx-parm>)

     <ttx-param> ::= <ttx-key> ':' <ttx-value>

     <ttx-key> ::= 'graphic' | 'control' | 'misc' | 'page' | 'private'

     <ttx-value> ::= <octetstring>

In the above, the first <printablestring> is the encoding of the first
portion of the teletex terminal identifier to be encoded, and the subse-
quent 0 or more <printablestrings> are subsequent portions of the
teletex terminal identifier.

5.19.  Facsimile Telephone Number

Values of type FacsimileTelephoneNumber are encoded according to the
following BNF:

     <fax-number> ::= <printablestring> [ '$' <faxparameters> ]

     <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.

5.20.  Presentation Address

Values of type PresentationAddress are encoded to have the representa-
tion described in [6].

5.21.  UTC Time

Values of type uTCTimeSyntax are encoded as if they were Printable
Strings with the strings containing a UTCTime value.






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5.22.  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"


5.23.  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.

5.24.  User Password

Values of type userPasswordSyntax are encoded as if they were of type
octetStringSyntax.

5.25.  User Certificate

Values of type userCertificate are encoded according to the following
BNF:

     <certificate> ::= <version> '#' <serial> '#' <signature-algorithm-id>
                     '#' <issuer> '#' <validity> '#' <subject>
                     '#' <public-key-info> '#' <encrypted-sign-value>

     <version> ::= <integervalue>

     <serial> ::= <integervalue>

     <signature-algorithm-id> ::= <algorithm-id>




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     <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-sign-value>

     <encrypted-sign-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>

Note that this certificate format is appropriate for reading, but cannot
be guaranteed to be verifiable. This is because the string DN format
used to encode the issuer and subject portions of the certificate does
not produce a completely reversible encoding (i.e., one cannot always
produce the original DER-encoded certificate from its string representa-
tion). By bilateral agreement, sites are free to exchange native DER-
encoded certificates that can be verified, but via an attribute type
name other than "userCertificate" or "caCertificate".

5.26.  CA Certificate

Values of type cACertificate are encoded as if the values were of type
userCertificate.

5.27.  Authority Revocation List

Values of type authorityRevocationList are encoded according to the fol-
lowing BNF:

     <certificate-list> ::= <signature-algorithm-id> '#' <issuer> '#' <utc-time>
                             [ '#' <revoked-certificates> ]
                             '#' <signature-algorithm-id>
                             '#' <encrypted-sign-value>

     <revoked-certificates> ::= 1*( '#' <revoked-certificate> )



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                             <signature-algorithm-id> '#' <encrypted-sign-value>

     <revoked-certificate> ::= <signature-algorithm-id> '#' <issuer> '#'
                             <serial> '#' <utc-time>

The syntactic components <signature-algorithm-id>, <issuer>,
<encrypted-sign-value>, <utc-time>, <subject> and <serial> have the same
definitions as in the BNF for the userCertificate attribute syntax.

Note that as with the "User Certificate" syntax above, values encoded in
this syntax are not guaranteed to be verifiable.  Also, servers which
implement or gateway to Directory systems supporting the 1993 or later
editions of the X.500 specifications may not be able to generate or
parse LDAP authority or certificate revocation lists, as the format
described in this section (based on the 1988 edition of X.509) is not
compatible with the syntax of X.509(1993).

5.28.  Certificate Revocation List

Values of type certificateRevocationList are encoded as if the values
were of type authorityRevocationList.

5.29.  Cross Certificate Pair

Values of type crossCertificatePair are encoded according to the follow-
ing BNF:

     <certificate-pair> ::= <forward> '#' <reverse>
                             | <forward>
                             | <reverse>

     <forward> ::= 'forward:' <certificate>

     <reverse> ::= 'reverse:' <certificate>

The syntactic component <certificate> has the same definition as in the
BNF for the userCertificate attribute syntax.

Note that as with the "User Certificate" syntax above, values encoded in
this syntax are not guaranteed to be verifiable.  Also, servers which
implement or gateway to Directory systems supporting the 1993 or later
editions of the X.500 specifications may not be able to generate or
parse LDAP authority or certificate revocation lists, as the format
described in this section (based on the 1988 edition of X.509) is not
compatible with the syntax of X.509(1993).






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5.30.  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'


5.31.  Other Mailbox

Values of the type otherMailboxSyntax are encoded according to the fol-
lowing BNF:

     <otherMailbox> ::= <mailbox-type> '$' <mailbox>

     <mailbox-type> ::= an encoded Printable String

     <mailbox> ::= an encoded IA5 String

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>.

5.32.  Mail Preference

Values of type mailPreferenceOption are encoded according to the follow-
ing BNF:

     <mail-preference> ::= "NO-LISTS" | "ANY-LIST" | "PROFESSIONAL-LISTS"


5.33.  MHS OR Address

Values of type MHS OR Address are encoded as strings, according to the
format defined in [10].

5.34.  Distribution List Submit Permission

Values of type DLSubmitPermission are encoded as strings, according to
the following BNF:

     <dlsubmit-perm> ::= <dlgroup_label> ':' <dlgroup-value>
                             | <dl-label> ':' <dl-value>

     <dlgroup-label> ::= 'group_member'



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     <dlgroup-value> ::= <name>

     <name> ::= an encoded Distinguished Name

     <dl-label> ::= 'individual' | 'dl_member' | 'pattern'

     <dl-value> ::= <orname>

     <orname> ::= <address> '#' <dn>
            |  <address>

     <address> ::= <add-label> ':' <oraddress>

     <dn> ::= <dn-label> ':' <name>

     <add-label> = 'X400'

     <dn-label> = 'X500'

where <oraddress> is as defined in RFC 1327.

5.35.  Photo

Values of type Photo are encoded as if they were octet strings contain-
ing JPEG images in the JPEG File Interchange Format (JFIF), as described
in [8].

5.36.  Fax

Values of type Fax are encoded as if they were octet strings containing
Group 3 Fax images as defined in [7].

6.  Security Considerations

Security considerations are not discussed in this document.

7.  Acknowledgements

Many of the attribute syntax encodings defined in this 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.

8.  Bibliography

[1]  The Directory: Selected Attribute Syntaxes.  CCITT, Recommendation
     X.520




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[2]  Information Processing Systems -- Open Systems Interconnection --
     The Directory: Selected Attribute Syntaxes

[3]  The COSINE and Internet X.500 Schema.  Paul Barker, Steve Kille;
     Request for Comment (RFC) 1274

[4]  The ISO Development Environment: User's Manual -- Volume 5: QUIPU.
     Colin Robbins, Stephen E. Kille

[5]  A String Representation of Distinguished Names.  Steve Kille, RFC
     1779

[6]  A String Representation for Presentation Addresses.  Steve Kille;
     Request for Comment (RFC) 1278

[7]  Terminal Equipment and Protocols for Telematic Services - Standard-
     ization of Group 3 facsimile apparatus for document transmission.
     CCITT, Recommendation T.4

[8]  JPEG File Interchange Format (Version 1.02).  Eric Hamilton, C-Cube
     Microsystems, Milpitas, CA, September 1, 1992

[9]  Lightweight Directory Access Protocol.  Wengyik Yeong, Tim Howes,
     Steve Kille, Request for Comment (RFC) XXXX

[10] Mapping between X.400 and RFC-822 Message Bodies.  H. Alvestrand,
     S.  Kille, R. Miles, M. Rose, S. Thompson, Request for Comment
     (RFC) 1495

9.  Author's Addresses

   Tim Howes
   University of Michigan
   ITD Research Systems
   535 W William St.
   Ann Arbor, MI 48103-4943
   USA
   +1 313 747-4454
   tim@umich.edu

   Steve Kille
   ISODE Consortium
   The Dome, The Square
   Richmond
   TW9 1DT
   UK
   +44-181-332-9091
   S.Kille@isode.com



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   Wengyik Yeong
   PSI Inc.
   510 Huntmar Park Drive
   Herndon, VA 22070
   USA
   +1 703-450-8001
   yeongw@psilink.com

   Colin Robbins
   NeXor Ltd
   University Park
   Nottingham
   NG7 2RD
   UK

   Mark Wahl
   ISODE Consortium Inc.
   3925 West Braker Lane, Suite 333
   Austin, TX 78759
   USA
   +1 512-305-0280
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Expires 11/11/96                                               [Page 15]