International Telecommunication Union News from the wonderful world

International Telecommunication Union News from the wonderful world of directories Erik Andersen Denmark Page ITU-T Study Group 17, Moscow, 30 March – 8 April 2005

Agenda ITU-T The position of X. 500/LDAP X. 500 enhancements a) b) c) d) Concept of Friends Attributes Paging on the DSP Maximum alignment with LDAP Enhancements to Public-key and Attribute certificates Enhancements to E. 115 a) Functional enhancements b) XML access dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 2

The X. 500/LDAP Directory ITU-T An LDAP or X. 500 directory is a general purpose directory Gives a set of specifications for: how objects are represented by entries in a directory how objects represented in a directory are named how information about objects is created, organised, interrogated, updated and deleted A directory can be distributed allowing: the establishment of a global Directory information to be maintained by the owner of information a separation between public and private domains possibility for replication of information dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 3

Relationship between X. 500 and LDAP (Lightweight Directory Access Protocol) ITU-T X. 500 LDAP originally developed for X. 500 access Later developed own server specifications Uses the X. 500 model Identical in many ways, except for syntax X. 500: Full use of ASN. 1 LDAP: (ABNF) Simple ASN. 1 and Augmented Backus-Naur Form Most X. 500 implementations support LDAP widely implemented and used dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 4

Editions of X. 500 Directory Specifications ITU-T Developed by ISO/IEC and ITU-T (former CCITT) as: ISO/IEC 9594 multi-part International Standard ITU-T X. 500 Series of Recommendations Four editions so far: Edition 2: ISO/IEC 9594: 1995 | ITU-T X. 500 (1993) Edition 1: ISO/IEC 9594: 1990 | CCITT X. 500 (1988) Edition 3: ISO/IEC 9594: 1998 | ITU-T X. 500 (1997) Edition 4: ISO/IEC 9594: 2001 | ITU-T X. 500 (2001) dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 6

X. 500 5 th edition enhancements ITU-T Expected publication: During 2005 Concept of Friends Attributes Paging on the DSP Maximum alignment with LDAP Enhancements to Public-key and Attribute certificates dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 7

Friend attributes ITU-T Attribute subtyping – same syntax: name common. Name surname locality. Name given. Name Friend attributes – possibly different syntaxes: comm. Address dates telephone. Number url (E. 164 syntax) (RFC 1738 syntax) ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 email (RFC 822 syntax) 8

Paged results on the DSP ITU-T DSP paged result Bound-DSA paged result User DUA DAP DSP DSP Bound DSA DSP DSA dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 DSA DSP DSA 9

Relationship between X. 500 and LDAP (Lightweight Directory Access Protocol) ITU-T X. 500 dates LDAP ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 10

Relationship between X. 500 and LDAP with maximum alignment ITU-T X. 500 dates LDAP ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 11

Maximum X. 500 alignment with LDAP ITU-T NOTE – One way alignment o Alignment of concepts – add LDAP concepts to make LDAP concepts a subset of X. 500 concepts. o Simplify specifications – removal of dependency of lower layer documentation o Alignment of operations (replace value) o Multiple namespaces (Directory Information Trees) o Directory consisting of LDAP and X. 500 server mix o ISO 10646 (UTF-8) matching o Component matching dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 12

A distributed directory ITU-T LDAP server DUA DSA User DAP LDAP DSA DSP LDAP User client LDAP dates DSA DSP A directory DSA ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 DUA 13

Matching problem ITU-T Filter key. Usage = digital. Signature And policy. Indentifier = { a b d } Directory entry Attribute dates Certificate 1 Certificate 2 key. Usage = digital. Signature key. Usage = data. Encipherment certificate. Policies = { … policy. Identifier = { a. b. c}} certificate. Policies = { … policy. Identifier = { a. b. d}} ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 14

Component matching rule ITU-T Component. Match against component n Evaluate to TRUE if match Attribute value Component m Component n Component o dates Can be combined by AND, OR and NOT operations in any combination and nesting level onto a particular attribute value of a particular attribute type Evaluates to TRUE if just one attribute value of the attribute type evaluates to TRUE ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 15

Directory. String ITU-T Directory. String { INTEGER : max. Size } : : = CHOICE { dates teletex. String Teletex. String (SIZE (1. . max. Size)), printable. String Printable. String (SIZE (1. . max. Size)), bmp. String BMPString (SIZE (1. . max. Size)), universal. String Universal. String (SIZE (1. . max. Size)), u. TF 8 String UTF 8 String (SIZE (1. . max. Size)) } ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 16

ISO/IEC 10646 The base character set standard ITU-T dates ISO/IEC 10646 - Universal Multiple-Octet Coded Character Set (UCS) Every character is coded in 4 octets Allows encoding of all characters used by written languages all over the world The practical realisation is specified in the Unicode standard (produced by a consortium) Supports multiple encoding formats: UTF-8 - octet oriented BMP (UCS-2) - half word oriented UTF-16 - half word oriented UCS-4 (UTF-32) - word oriented ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 17

UCS Transformation Format 8 (UTF-8) ITU-T Defined in Annex D of ISO/IEC 10646 -1 : 2003, Universal Multiple-Octet Coded Character Set (UCS) Required by (almost) all Internet specifications dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 19

Format of octets in a UTF-8 sequence ITU-T dates Octet usage Format (binary) No. of free bits Max UCS-4 value 1 st of 1 0 xxxxxxx 7 00 00 00 7 F 1 st of 2 110 xxxxx 5 00 00 07 FF 1 st of 3 1110 xxxx 4 00 00 FF FF 1 st of 4 11110 xxx 3 00 1 F FF FF 1 st of 5 111110 xx 2 03 FF FF FF 1 st of 6 1111110 x 1 7 F FF FF FF Continuation 2 nd. . 6 th 10 xxxxxx 6 ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 20

First problem ITU-T We need to compare names and values Some characters may be represented in several ways It is not possible to do a simple bitwise comparison to check if two names or values are equal! dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 22

Second problem ITU-T Comparison is most often done disregarding case differences All upper case letters have to be converted to lower case letters before comparison dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 23

String preparation ITU-T Text string 1 Text string 2 Transcoding Transcoded string 1 Transcoded string 2 Mapping Mapped string 1 Mapped string 2 Normalised string 1 Normalised string 2 Octet wise comparison dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 24

X. 509 enhancements ITU-T Notice of future revocation Notice of revoked group of entries Expired certificates on CRLs Advanced certificate matching rule XML encoded privilege information Clarifications Misc. enhancements to PMI Etc. dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 25

EIDQ Association ITU-T dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 26

Members (30 as at 17 Feb 2004) Source: David Stafford, General Secretary EIDQ Association 27

E. 115 - Computerized directory assistance ITU-T User International server Operator E. 115 protocol Local server dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 28

ITU-T Rec. E. 115 (2005) Computerized Directory Assistance ITU-T dates OSI stack removed Home grown TCP/IP support integrated in text Specifies two versions of the protocol Version 1: • The 1995 edition + all agreed extensions • All keywords specified in Annex • Complete rewrite and restructuring of 1995 edition • Added clarifications • ASN. 1 BER encoding • Support mandatory Version 2: • Keywords replaced by new fields – keyword concept no longer used • Several new enhancements • ASN. 1 BER and XML (or ASN. 1 XER) encoding • Future extensions using ITU-T procedure ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 29

Version 2 design criteria ITU-T o Keep backward compatibility • Unchanged fields use same tag • Tags reserved for obsolete fields • Common text for unchanged fields o Keep ASN. 1 and XML Schema Definitions (XSD) aligned • ASN. 1 XER encoding will produce same encoding as the XSD • ASN. 1 EXTENDED-XER encoding instruction used dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 30

Example of ASN. 1 specification ITU-T dates Inquiry. Part 1 : : = [ TAG: APPLICATION 0 ] IMPLICIT SET { message. Indicators [ATTRIBUTE] [TAG: 0] IMPLICIT E 115 String (SIZE(4)), international. Indicator [ATTRIBUTE] [TAG: 1] IMPLICIT E 115 Numeric. String (SIZE(8)), originating. Terminal. Code [ATTRIBUTE] [TAG: 2] IMPLICIT E 115 String (SIZE(8)), date. And. Time [ATTRIBUTE] [TAG: 3] IMPLICIT E 115 Numeric. String (SIZE(12))OPTIONAL, message. Number [ATTRIBUTE] [TAG: 4] IMPLICIT E 115 String (SIZE(4)) OPTIONAL } ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 31

Proximity search ITU-T dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 32

ITU-T END dates ITU-T Study Group 17, Moscow, 30 March – 8 April 2005 33