Learning Directory

1
Learning Directory

• 2000/09/16
• ??? ???????
• ??? (godslord_at_initech.com)

2
Goal

• Directory? ??? ?????? ??? ??
• LDAP?? ?? ??? ? ? ?? ??? ???

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What is Directory?

• Directory
• Noun. ?? ???
• X.500 X.400? ???? ?? ???? ??? distributed DB
• Directory? ??? entry?? ??? ??
• Object Oriented ???? ? ??? ??? ? ?? ?? ??? ??

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At the Beginning

• Requirement of X.400
• Naming persons email address
• Search, Add, Remove, Modify email address
• organizing hierarchically because its more
  intuitive
• Thats exactly same as Phone Book!! ?

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Directory? ??? ??

• DIT
• Entry
• Attribute
• Schema
• DN RDN

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DIT

• DIT Directory Information Tree
• ??? ??? ?? Entry ?? Object?? ???
• ??? n-ary tree??, DIT??? ??? ???? ?? tree ?????
  ??? ??? ???

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Entry

• Entry DIT? ???? ??. Object? ???? ??
• Entry? ?? ?? ??(Attribute)? ????, ? ???? ??? ??
  Entry? ????

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Attribute

• Attribute Entry? ??? ???? ??
• Attribute? Attribute? ??? ???? type? ? ?? ????
  value?? ????.
• Entry? objectclass?? attribute? ??? ??? ??

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Schema

• Schema a syntax of DIT
• Schema? DIT?? ??? objectclass? ???, attribute?
  ??? ?? ?? ??, ??? ?? ??? ?? ?? ???? ?? ???? ???.
• Schema checking Syntax checking

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Sample Schema

• Attribute Definition
• ( 2.5.18.3 NAME 'creatorsName' EQUALITY
  distinguishedNameMatch
• SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
• SINGLE-VALUE NO-USER-MODIFICATION USAGE
  directoryOperation )

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Sample Schema

• Object Class
• objectclass person
• requires
• objectClass,
• sn,
• cn
• allows
• description,
• seeAlso,
• telephoneNumber,
• userPassword

12
??? ????
So am I
? ????
?? ????
Me too
????
?? ????
13
??? ???
? Rocky
? Smith
? Martin
? Robert
? Eric
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DN RDN

• DN distinguished name
• RDN relative distinguished name
• DN? DIT ??? ???? ? Entity? ???? ??.
• RDN? sibiling ???? ???? ? Entity? ???? ??

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DN RDN (continued)

• Entry? ??? Entry? ??? ?? ?? attribute? ?? ? ? ??.
• RDN? ???? sibiling entry ???? ? entry? ??? ?? ???
  attributevalue? ???? ??? ? ??.
• DN? DIT? Root Entry? ?? ?? Entry? ???? ?? ?? ??
  Entry?? RDN? ????(not ??)

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Sample DIT
CN???,OU???, OU????, O???????, L?????,CKR
Entry
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Directory? ??

• ?? ??? ????
• Replication
• Referral
• Scalable
• High performance
• Logical DataBase
• Connectivity with CORBA and JAVA

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Object Oriented

• DIT? ???? Entry? Object
• ObjectClass Entry? ???
• Structural Class
• Entry? ?? ??? ??
• Auxiliary Class like interface in JAVA
• Entry? ???? ??? ??

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Object Oriented Example

• Initech is organization(company), but now it does
  CA service. How can we make entry of Initech in
  DIT?

Objectclass organization
Objectclass Certification Authority
Organization Certification Authority


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X.500 DAP and LDAP

• X.500 DAP
• DAP Directory Access Protocol
• Too heavy to use(full ASN.1 BER encoding, etc)
• LDAP
• Light-weight Directory Access Protocol
• Protocol carried directly over TCP or other
  transport
• Use direct string encoding rather than BER
  encoding as many as possible
• LDAP is subset of DAP

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Compare DAP LDAP

• DN encoding
• SEQUENCE
• SET
• SEQUENCE
• OBJECT IDENTIFIER ( 2.5.4.6 )
• PRINTABLE STRING KR
• SEQUENCE
• OBJECT IDENTIFIER ( 2.5.4.10 )
• PRINTABLE STRING Initech, Inc
• When DER encoded, its 34 byte. And complex
  encoding process.
• OInitech, Inc,CKR
• Its 21 byte. And simple encoding process.

22
Directory ???? ???

• Many Directory enabled applications
• Internet Explorer, Netscape Communicator, Eudora,
  etc
• Sendmail/named/ support LDAP as backend
  DataBase
• Various language support LDAP(ex.
  PHP/MFC/JAVA/Perl/)
• Backend Repository of Intranet or Internet Service

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Directory? ??? ? ??!

• ??? Netscape Navigator or IE
• LDAP URL Search filter
• Ldap//ldap.host.nameport/ousearch,obase?return
  attributelist?searchmethod?searchfilter
• Searchmethod one,base,sub
• Searchfilter prefix expression
• Operators ,,!,gt,lt,,,

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?? ??

• Ldap//venus.initech.com/oinitech,ckr??sub?((ma
  ilinitech)(cn??))
• Ldap//venus.initech.com/oinitech,ckr??one?((cn
  ?)(cn?))
• Ldap//venus.initech.com/oupeople,oinitech,ckr?
  ?sub?((cn?)(!(mailinitech)))

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References

• RFC-2251 LDAP v3? ??? RFC ???
• http//www.openldap.org
• http//www.opendirectory.com
• http//developer.netscape.com
• IETF LDAP working group