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Network Working Group                                        B. JenningsRequest for Comments: 1943                    Sandia National LaboratoryCategory: Informational                                         May 1996Building an X.500 Directory Service in the USStatus of this Memo   This memo provides information for the Internet community.  This memo   does not specify an Internet standard of any kind.  Distribution of   this memo is unlimited.Abstract   This document provides definition and recommends considerations that   must be undertaken to operate a X.500 Directory Service in the United   States.  This project is the work performed for the Integrated   Directory Services Working Group within the Internet Engineering Task   Force, for establishing an electronic White Pages Directory Service   within an organization in the US and for connecting it to a wide-area   Directory infrastructure.   Establishing a successful White Pages Directory Service within an   organization requires a collaborative effort between the technical,   legal and data management components of an organization. It also   helps if there is a strong commitment from the higher management to   participate in a wide-area Directory Service.   The recommendations presented in the document are the result of   experience from participating in the Internet White Pages project.Table of Contents   1.0     Introduction                                            2   1.1     Purpose of this Document                                2   1.2     Introduction to Directory Services                      2   2.0     The X.500 Protocol                                      4   2.1     Introduction                                            4   2.2     Directory Model                                         4   2.3     Information Model                                       5   2.4     Benefits and Uses for X.500 Directory Service           6   2.5     Other Applications of X.500                             7   3.0     Legal Issues                                            8   3.1     Introduction                                            8   3.2     Purpose of the Directory                                8   3.3     User Rights                                             9   3.4     Data Integrity                                          9Jennings                     Informational                      [Page 1]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   3.5     Protection of the Data                                 10   3.6     Conclusions                                            10   4.0     Infrastructure                                         11   4.1     Introduction                                           11   4.2     A Well Maintained Infrastructure                       11   4.3     DUA Interfaces for End Users                           12   5.0     Datamanagement & Pilot Projects                        13   5.1     Simple Internet White Pages Service                    13   5.2     InterNIC                                               13   5.3     ESnet                                                  14   6.0     Recommendations                                        14   6.1     General                                                14   6.2     Getting Started                                        14   6.3     Who are the Customers                                  14   6.4     What are the Contents of the Directory                 15   6.5     What are the Rights of the Individuals                 15   6.6     Data Integrity                                         16   6.7     Data Security                                          16   6.8     Data Administration                                    17   6.9     Conclusion                                             17   7.0     References                                             18   8.0     Glossary                                               19   9.0     Security Considerations                                22   10.0    Author's Address                                       221.0     Introduction1.1     Purpose of this Document   This document provides an introduction for individuals planning to   build a directory service for an organization in the US. It presents   an introduction to the technical, legal, and organizational aspects   of a directory service. It describes various options to organizations   who want to operate an X.500 Directory service and illustrates these   with examples of current X.500 service providers.1.2     Introduction to Directory Services   An electronic directory server is an electronic process that provides   a list of information provided via electronic access. This   information is variable in content, however it should be explicitly   defined by the directory purpose. Information about people,   organizations, services, network hardware are just a few examples of   data content that a directory service can provide. The aim of an   X.500 Directory service is to make using the directory intuitive and   as easy to use as calling for directory assistance. The X.500   Directory service is an international standard ratified by the   International organization for Standardization (IS) and the ITU-TJennings                     Informational                      [Page 2]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   International Telecommunication Union formerly (CCITT) in 1988 [1].   The Directory is intended to be global service comprised of   independently operated and distributed Directory Service Agents   (DSAs), that provide information in the form of a White Pages Phone   Directory.   Electronic mail communication benefits from the existence of a global   electronic White Pages to allow network users to retrieve addressing   information in an intuitive fashion. Manual searching for names and   addresses, specifically electronic addresses, can take a great deal   of time. A White Pages directory service can enable network users to   retrieve the addresses of communication partners in a user friendly   way, using known variables such as common name, surname, and   organization to facilitate various levels of searches.   In order to make global communication over computer networks work   efficiently, a global electronic White Pages service is   indispensable. Such a directory service could also contain telephone   and fax numbers, postal addresses as well as platform type to   facilitate in translation of documents between users on different   systems. An electronic White Pages may prove to be useful for   specific local purposes; replacing paper directories or improving   quality of personnel administration for example. An electronic   directory is much easier to produce and more timely than paper   directories which are often out of date as soon as they are printed.   The Internet White Pages Project provides many companies in the US   with an opportunity to pilot X.500 in their organizations.   Operating as a globally distributed directory service, this project   allows organizations in a wide variety of industry type to make   themselves known on the Internet and to provide access to their staff   as desired.   Some organizations, such as ESnet agreed to manage directory   information for other organizations. ESnet maintains data at their   site for all the national laboratories. They provide assistance to   organizations in defining their directory information tree (DIT)   structure. They also provide free access to the X.500 Directory via   Gopher, WWW, DUAs, whois and finger protocols.   The InterNIC is another directory services provider on the Internet.   To date [June 1995] they hold X.500 directory data for 52   organizations and provide free access to this data via various   protocols: X.500 DUA, E-Mail, whois, Gopher and WWW.   To find the most current listing of X.500 providers seeRFC 1632 -   Catalog of Available X.500 Implementations [2].Jennings                     Informational                      [Page 3]

RFC 1943     Building an X.500 Directory Service in the US      May 19962.0     The X.500 Protocol2.1     Introduction   This chapter provides the basic technical information necessary for   an organization to begin deploying an X.500 Directory Service. It   provides a brief introduction to the X.500 protocol and the   possibilities that X.500 offers.2.2     The Directory Model   X.500 Directory Model is a distributed collection of independent   systems which cooperate to provide a logical data base of information   to provide a global Directory Service. Directory information about a   particular organization is maintained locally in a Directory System   Agent (DSA). This information is structured within specified   standards. Adherence to these standards makes the distributed model   possible. It is possible for one organization to keep information   about other organizations, and it is possible for an organization to   operate independently from the global model as a stand alone system.   DSAs that operate within the global model have the ability to   exchange information with other DSAs by means of the X.500 protocol.   DSAs that are interconnected form the Directory Information Tree   (DIT). The DIT is a virtual hierarchical data structure. An X.500   pilot using QUIPU software introduced the concept of a "root" DSA   which represents the world; below which "countries" are defined.   Defined under the countries are "organizations". The organizations   further define "organizational units" and/ or "people". This DIT   identifies the DIT for the White Pages X.500 services.   Each DSA provides information for the global directory. Directories   are able to locate in the hierarchical structure discussed above,   which DSA holds a certain portion of the directory. Each directory   manages information through a defined set of attributes and in a   structure defined as the Directory Information Base (DIB).   A DSA is accessed by means of a Directory User Agent (DUA). A DUA   interacts with the Directory by communicating with one or more DSAs   as necessary to respond to a specific query. DUAs can be an IP   protocol such as whois or finger, or a more sophisticated application   which may provide Graphical User Interface (GUI) access to the DSA.   Access to a DSA can be accomplished by an individual or automated by   computer application.Jennings                     Informational                      [Page 4]

RFC 1943     Building an X.500 Directory Service in the US      May 19962.3     The Information Model   In addition to the Directory Model, the X.500 standard defines the   information model used in the Directory Service. All information in   the Directory is stored in "entries", each of which belong to at   least one "object class". In the White Pages application of X.500   object classes are defined as country, organization, organizational   unit and person.   The object classes to which an entry belongs defines the attributes   associated with a particular entry. Some attributes are mandatory   others are optional. System administrators may define their own   attributes and register these with regulating authorities, which will   in turn make these attributes available on a large scale.   Every entry has a Relative Distinguished Name (RDN), which uniquely   identifies the entry. A RDN is made up of the DIT information and the   actual entry.   The Directory operates under a set of rules know as the Directory   schema.  This defines correct utilization of attributes, and ensures   an element of sameness throughout the global Directory Service.   Under the White Pages object class "Person" there are three mandatory   attributes:        objectClass     commonName      surName   These attributes along with the DIT structure above, define the RDN.   An example of an entry under Sandia National Laboratory is shown   here: @c=US@o=Sandia National Laboratory@ou=Employees@cn=Barbara   Jennings                                   root                                   /  \                                  /    \                                c=US    c=CA                                /  \                               /    \                  o=Sandia National   o=ESnet                    Laboratory                   /   \                  /     \            ou=Employees  ou=Guests              /                \             /                  \     cn=Barbara Jennings        cn=Paul BrooksJennings                     Informational                      [Page 5]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   Organizations may define the best structure suited for their DIT.   Typically an organizations DIT will look very much like the   organizations structure itself. A DIT structure is determined by   naming rules and as such, becomes the elements unique Relative   Distinguished Name (RDN). The DIT structure may also be dependent on   whether the DSA information is administered by a flat file or a   database. Extra consideration to designing of the DIT structure   should be taken when using flat files versus a database, as it takes   longer to search through a flat file if the tree structure becomes   too complex or intricate. To obtain information on recommended schema   for DIT structuring seeRFC1274 [3].2.4     Benefits and Uses for X.500 Directory Service   The nature of the X.500 Directory makes it suitable for independently   operated segments that can be expanded to global distribution. The   benefits for local directory use are:   - with the distributed nature of the service, an organization may   separate the responsibility for management of many DSAs and still   retain the overall structure;   - the robustness of this service allows it to provide information to a   wide range of applications. Whereas globally integrated projects must   conform to a specific DIT, independent X.500 operations may define   unique DITs, object classes and attributes as per their specific   needs;   - X.500 is a good alternative for paper directories, offering the   ability to update and modify in an interactive mode. This allows a   company to provide the most current information with less cost and   effort;   - because of the electronic base of X.500, other electronic   applications may interact with the application without human   intervention.   The benefits for global directory use are:   - the distributed nature of X.500 is well suited for large global   applications such as the White Pages Directory. Maintenance can be   performed in a distributed manner;   - X.500 offers good searching capabilities from any level in the DIT.   Also with "User Friendly Naming" in place, searches are very   intuitive;Jennings                     Informational                      [Page 6]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   - there are DUA interfaces for the White Pages service available for   all types of workstations. For an overview of X.500 software referenceRFC1632.   - X.500 is an international standard. Using such a standard ensures   interoperability within the worldwide base.2.5     Other Applications of X.500   In addition to the White Pages, X.500 can be used as a source for any   type of information that needs a distributed storage base.   The University of Michigan is using X.500 for electronic mail   routing. Any mail coming to the university domain, umich.edu; gets   expanded out to a local address that is stored in the rfc822Mailbox   attribute. The University also operates a standard X.500 name server   which provides name lookup service of over 200,000 names. They use   the Lightweight Directory Access Protocol (LDAP) [11].   An implementation of the X.500 Standard directory service has been   incorporated into the Open Software Foundation (OSF) Distributed   Computing Environment (DCE). This component, known as the Global   Directory Service (GDS), provides an area where distributed   application clients can find their application servers. The GDS, in   response to requests made by other clients, provides the unique   network address for a particular DCE resource.  Because it is based   on a international standard, GDS can offer access to resources among   users and organizations worldwide. This scalable service can be   performed in DCE environments that range in size from the very small   to the very large.   Lookup services can be implemented into a variety of applications.   Cambridge University in Great Britain implemented the X.500 directory   service into an employee locator application. Based on badge sensors   at strategic locations, this application can determine the   whereabouts of an employee on the campus. As the individual moves   about, the sensors register their location in an X.500 Directory.   Digital Signature Service (DSS) and Privacy Enhanced Mail (PEM) work   on the principal of a directory key server which generates and   provide users with "public" codes that match previously registered   "private" codes. Only the recipient can decipher messages sent in   this fashion. The X.509 [4] standard for key certificates easily fits   within the structure of the X.500 Directory Service.Jennings                     Informational                      [Page 7]

RFC 1943     Building an X.500 Directory Service in the US      May 19963.0     Legal Issues3.1     Introduction   Currently in the United States, there are no specific legal rules for   the information that is provided via an electronic directory service.   Various organizations and groups associated with usage of the   Internet, noting a need to address privacy and data integrity issues,   have prepared directives to address this issue. Two such areas   addressed are those of the rights of registrants included in the   directory and the responsibility of administrators to guarantee the   integrity of such data.   Registries containing information that is related to an individual is   freely transferred and unregulated in the US, unless the provider of   the data is an agency or an holder of sensitive information as   defined by federal legislation and further may differ for each state.   An agency is defined as: any executive department, military   department, Government corporation, Government controlled   corporation, or other establishment in the executive branch of the   Government (including the Executive Office of the President), or any   independent regulatory agency. Sensitive data can be financial   records, medical records, and certain legal documents. As previously   noted, each state has their own legislation on sensitive or private   data.The registered persons have little recourse to control list   information short of filing a lawsuit against the information   provider.   For individuals who transfer data across country boundaries, it is   important to understand that other countries may have legislation to   regulate data. Prior to requesting list information from these   countries, an administrator should review applicable legislation and   have some mechanism in place to ensure how data will be handled once   it is crosses the border. Policy Statements for some countries have   been prepared and are provided for via Code of Conduct papers.3.2     Purpose of the Directory   The operational intent including presentation data and list   registrants and access rights must be clearly defined and stated.   Initially this provides the skeleton of the DIT. Eventually a   statement such as this may provide a basis legally justifying the   directory.   All data presented must be defined in the purpose. If for example, a   directory is for the sole purpose of providing professional   addressing information - an entry would include name, postal address,   office telephone, facsimile number, electronic mail address andJennings                     Informational                      [Page 8]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   company name.  Private address information listing the home address   or phone would be prohibited as would any other information not   directly related to addressing.3.3     User Rights   The North American Directory Forum (NADF) has published a document   that defines the User Bill of Rights [5]. This document defines an   individuals rights regarding the public release of personal or   private information.  Among other issues stated, the user has the   right to be notified regarding the inclusion of their information in   a data registry as well as the right to examine and have incorrect   information changed.   This paper is specifically written for the North American Directory   Forum and recommends compliance with US or Canadian laws regulating   privacy and access information.   Although current US legislation does not include all the suggestions   in this document, it is the responsibility of the controller of the   data to respect the rights of the individuals. These recommended   rules can be seen as respect for the individual and the considerate   controller will follow these guidelines within any boundaries that   they may be mandated by.3.4     Data Integrity   An information provider has the responsibility to guarantee the data   that they make available to users. The integrity of a data source is   heavily weighted by the accuracy and timeliness of the contents.   Interoperable data sources must have concurrence of these factors as   well. The degree to which an information provider can guarantee the   validity of the data that they present, reflects on the validity of   the provider in general.RFC 1355 [6], suggests that a data source   enable accuracy statements describing the process that the individual   NIC will use to maintain accuracy in the database.   In the European community, it is a legal requirement that the   information provider guarantee accurate data.   The controller of the information needs to be certain of the primary   source of data. When possible, the controller should develop routines   of random checks to validate the registry data for correctness.Jennings                     Informational                      [Page 9]

RFC 1943     Building an X.500 Directory Service in the US      May 19963.5     Data Security   A Directory Service with non-authenticated access from the Internet   is difficult to protect from unauthorized use. Unauthorized use being   defined by each organization within the directory purpose statement.   Typical misuse being by individuals who attempt to duplicate the   directory for unauthorized purposes. Other security measures include:   Access Control Lists (ACLs), limitations on number of entries   returned to a query, and time to search flags. The result of such   controls will affect the legitimate user as well as the user they are   intended to block.   An alternative that may provide protection from misuse is to create   and display an attribute with each entry stating non-approved usage.   This feature will also provide evidence of restricted use in the   event that a legal case is necessary to stop unauthorized access.   The responsibility again falls on the data provider/implementor of   the directory service. Astute programmers will create or make use of   existing tools to protect against data destruction, falsification,   and misuse.3.6     Conclusions   User Rights, Data Integrity and Protection of data should not be   considered merely in an effort to abide by legal rulings; they should   be the intention of a good data source. A successful Directory   Service must be aware of the requirements of those individuals   inclusive in the list as well as those of the directory users.   In general, at the minimum the following conditions should be   observed:        1. Define the purpose of the Directory.        2. Initially inform all registrants of their inclusion in           a Directory.        3. Prevent the use of data beyond the stated purpose.        4. Limit the attributes associated to an entry within           boundaries of the purpose.        5. Work towards a suitable level of security.        6. Develop a mechanism to correct/remove faulty data           or information that should not be in the Directory.Jennings                     Informational                     [Page 10]

RFC 1943     Building an X.500 Directory Service in the US      May 19964.0     Infrastructure4.1     Introduction   The White Pages Project, currently operated by Performance Systems   International (PSI) provides a reliable QUIPU infrastructure for   sites wishing to provide their own X.500 directory. Started in 1989   as the NYSERNet White Pages Pilot Project it was the first   production-quality field test of the Open Systems Interconnection   (OSI) technology running on top of TCP/IP suite of protocols [7].   This pilot X.500 Directory, provided a real-time testbed for a   variety of administrative and usage issues that arise. Today, more   than 30 countries participate in the globally distributed project   with over 1 million entries. The White Pages pilot is one of 37 other   pilots cooperating to provide information in the Nameflow-PARADISE   directory; an European project.   Initially the software was public domain, QUIPU X.500 [8]. This   "shareware" application in conjunction with administrative services   provided free of charge by PSI, allowed for a truly distributed X.500   Directory Service to operate.   In keeping with the Internet rules of operation, the lack of the US   regulations, the suggestions of North American Directory Forum and   the Internet Engineering Task Force (IETF), the complications that   arise from multi-distributed data as a service can be overwhelming.   PSI took on the challenge to provide such a service, and continues to   ensure operations today.4.2     A Well Maintained Infrastructure   This distributed information service involves the cohesive effort of   all of the participating organizations. The ISO Development   Environment (ISODE) implementation of the OSI Directory, provided the   attributes and uniformity to facilitate this effort.   The primary DSA for the PSI Project is named Alpaca. Operating on a   Sun Sparc 10 with 120 megabytes of memory, this host serves as the   Master for the DSAs of 117 organizations under c=US. Redundancy for   Alpaca is provided by two sources, Fruit Bat operated by PSI and Pied   Tamarin operated by the InterNIC. Slave updates to this host are   provided on a nightly basis from the individual DSAs.   The data presentation is hierarchical in nature and emulates the   common white pages telephone book. The information provided contains   at minimum: a common name, voice phone listing, and electronic mail   addressing. Each entry has a uniqueness associates with it; the   relative distinguished name which is comprised of the entireJennings                     Informational                     [Page 11]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   directory information tree. The DITs may vary slightly, but each must   contain an organization, and a person. The nature of the directory   and the structure of the actual organization for whom the directory   is being provided contribute to the overall DIT structure. The   following is a list of commonly used attributes:commonName      physicalDeliveryOfficeName      stateOrProvinceNamedescription     photo                           streetAddressuserid          postOfficeBox                   surnamefavouriteDrink  postalAddress                   telephoneNumbertitle           rfc822Mailbox                   facsimileTelephoneNumber4.3     DUA Interfaces for End Users   There are a variety of user interfaces on the market today that will   provide Directory User Agent access to the X.500 Directory. Standard   protocols such as fred, whois, whois++, finger, are used widely.   Interfaces are also available via World-wide Web browsers and   electronic mail.   Vendors providing DUAs include ISODE Consortium, NeXor, and Control   Data Corporation. These applications operate in conjunction with the   vendor provided DSAs.   Historically DUA interfaces were difficult to implement and required   the entire OSI stack. Implementing such a product on a PC or Apple   platform required skillful programming. The executable for these   platforms were usually very large. The IETF has since defined and   standardized the Lightweight Directory Access Protocol (LDAP) [11]; a   protocol for accessing on-line Directory services which offers   comparable functionality to the Directory Access Protocol (DAP). It   runs directly over TCP and is used by nearly all X.500 clients. LDAP   does not have the overhead of the various OSI layers and runs on top   of TCP/IP.   The functionality varies by specific DUA. Each offers access to the   X.500 Directory. Most offer the ability to make modifications to   entries. There are a few that offer Kerberos authentication.   Further information on LDAP clients for specific platforms can be   found on the University of Michigan WWW server:http://www.umich.edu/~rsug/ldap.   Another interface that has been tested and recommended for users by   our Dutch (Surfnet) colleagues is Directory Enquiry (DE). Originally   developed by University College London for the Paradise project in   Europe, the engineers at Surfnet have selected DE as the best   interface for "dumb" terminals. They have also translated theJennings                     Informational                     [Page 12]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   interface into Dutch for their local users [12].   Ideally, users should be able to access X.500 directly from their   electronic mail applications. Vendors (other than the ones mentioned   above) have been slow to incorporate the X.500 Standards into their   electronic mail applications.5.0     Datamanagement & Pilot Projects5.1     Simple Internet White Pages Service   A wide variety of directory services retrieval protocols has emerged   in the time since the original Internet White Pages was begun in   1989. To ensure that decentralized implementations will have   interoperability with other providers, the IETF Integrated Directory   Services Working Group, is working to create a draft focusing on the   common information and operational modeling issues to which all   Internet White Pages Services (IWPS) must conform to.   Utilizing current information servers, the conceptual model described   includes issues regarding naming, schema, query and response issues   for a narrowly defined subset of directory services. The goal of this   paper is to establish a simple set of information objects, coupled   with a basic set of process requirements that will form a basis which   can lead to ubiquitous IWPS. With this goal in mind, it will be   easier to proved a consistent User view of the various directory   services.5.2     InterNIC   The InterNIC [9] is a collaborative project of two organizations   working together to offer the Internet community a full scope of   network information services. Established in January 1993 by the   National Science Foundation, the InterNIC provides registration   services and directory and database services to the Internet.   (Internet a global network of more than 13,000 computers networks,   connecting over 1.7 million computers and used by an estimated 13   million people.) In keeping up with the exponential growth of the   Internet, the InterNIC provides a guide to navigate the maze of   available resources.   InterNIC provides two types of services; InterNIC directory and   database services and registration services. AT&T provides the   directory and database services, acting as the pointer to numerous   resources on the network offering X.500 to help users easily locate   other users and organizations on the Internet.Jennings                     Informational                     [Page 13]

RFC 1943     Building an X.500 Directory Service in the US      May 19965.3     ESnet   The Energy Sciences Network [10], is a nationwide computer data   communications network whose primary purpose is support multiple   program, open scientific research. As part of this support, ESnet   offers networking services including information access and   retrieval, directory services, group communications series, remote   file access services and infrastructure services. As a early member   of the White-Pages Pilot Project, ESnet continues to be a part of the   worldwide distributed directory service based on the ISO/OSI X.500   standard. There are over nineteen ESnet organization represented in   the directory, comprising over 120,000 entries. ESnet provides access   to seven other sites via the X.500 DSAs.6.0     Recommendations6.1     General   The X.500 Directory technology is available through several options.   Vendors can provide consultation for schema design as well as supply,   install, and support the software to perform the operations required.   For smaller organizations or companies who do not want to administer   their own DSA, there are providers available who will maintain the   DSAs remotely and provide this service to the Internet. Those with   network and management expertise, can either operate independently or   join one of several white pages directory projects. Careful   consideration must be given to the initial investment required and   the required maintenance process.6.2     Getting Started   Successful initialization of a directory service requires a   systematic approach. The complexity of offering this type of service   becomes more apparent as implementation progresses. Several aspects   must be considered as this service becomes a cooperative effort among   the technical, administrative, organizational, and legal disciplines.   Procedures must be defined and agreed to at the initial phase of   implementing an X.500 Directory service [13].  The following are   issues that should be addressed in these procedures.6.3     Who are the Customers?   Defining the customer and the customer requirements will determine   the scope of service to offer. What is the primary purpose for the   directory service? A company may find it desirable to do away with a   paper directory while simultaneously providing the current directory   information. The directory may be for internal use only or expanded   to any users with Internet access. Will the customer use theJennings                     Informational                     [Page 14]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   directory for e-mail address only or is other locational information   such as postal address and telephone number a requirement?   The directory may provide information to electronic customers such as   distributed computing applications as well. In this case, the data   must be provided in machine readable format.   Will the customers extend across country boundaries? Information may   be considered private by one country and not by another. It is   necessary to be aware of the legalities and restrictions for the   locality using the data.  Some counties have published a Code of   Conduct with the IETF, explicitly stating the legal restrictions on   directory and list data. Check the archives to determine if the   country with whom information will be shared has presented such   information.6.4     What are the contents of the Directory?   The information presented in the directory is tightly coupled with   the purpose. If the purpose is to provide addressing information for   individuals, then customary information would include: Name, address,   phone, e-mail address, facsimile number, pager, etc. If the use of   the directory is to facilitate electronic mail routing then the   destination mail address needs to be included for each user. No other   information should be presented in the directory if it is not   directly related to the purpose.   If the directory is internal only, it may be desirable to include the   registrants title as well. Remember that information available on the   Internet is generally open to anyone who wants to access it.   Individuals wishing to target a specific market may access   directories to create customer mailing lists.   The structure or schema of the X.500 Directory must be an initial   consideration. Will the hierarchy follow the company structure or is   a different approach more practical? How many entries will there be   in the directory five or 50,000? A complex hierarchyfor thousands of   users may affect the efficiency of queries.6.5     What are the rights of the individuals?   The subjects included in the directory shall have well defined   rights.  These may be mandated by company policy, legal restrictions,   and the ultimate use of the directory. For a basic Internet White   Pages Service these rights may include:Jennings                     Informational                     [Page 15]

RFC 1943     Building an X.500 Directory Service in the US      May 1996        1. the option of inclusion in the directory        2. the right of access to the information        3. the right to have inaccurate entries corrected   The terms and conditions for employees of an organization may affect   these rights. On becoming an employee of any organization, an   individual inevitably agrees to forego certain personal privacies and   to accept restrictions.   Every organization should develop and publish the "rights" that can   be expected by the list registrants.6.6     Data Integrity   Information that needs to be included in the directory may come from   various sources. Demographic information may originate from the human   resources department. Electronic mail addresses may be provided by   the computer network department. To guarantee data integrity, it is   advised that the data be identified and maintained as corporate   information.   The required timeliness of the data is unique for each DSA. Updates   to the data may be a frequent as once a day or once a month. Updates   to the data must be provided on a regular basis. In cases where data   is time sensitive, an attribute should be included to display the   most recent maintenance date.   A regular check for data accuracy should be included in the directory   administration. Faulty information may put an organization in breach   of any data protection laws and possibly render the company as   unreliable.6.7     Data Security   Securing networked information resources is inherently complex.   Attempts must be made to preserve the security of the data. These may   include access control lists (ACLs), limiting the number or responses   allowed to queries, or internal/external access to the directory.   The 1993 recommendations have added a complex access control model   that is designed to tightly restrict the access that users may have   to the information in the Directory. Local protection is configured   by the implementor. A secure X.500 Directory should provide tools to   protect against destruction, falsification, and loss of data.   There is not a tool yet that will protect against the misuse of data.   There are flags and limits that can be set from within the   application that will serve somewhat as a barrier to such unwantedJennings                     Informational                     [Page 16]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   use. Any restrictions however, also will affect the legitimate users.   One suggestion is to post a notice of illegitimate use within each   entry. This of course will only serve as a deterrent and as an asset   should legal action be required.   Again, caution must be taken when transferring data between country   and state borders. In the US data regulations differ from state to   state.6.8     Data Administration   The decentralized nature of the X.500 Directory service means that   each organization has complete control over the data. As part of a   global service however, it is important that the operation of the DSA   be monitored and maintained in a consistent manner. Authorization   must be given to the local manager of the information and in some   cases, the subjects included in the directory may also have   modification privileges.   Once the service is running, the importance of guaranteed operation   can not be overstated. Maintenance of the local Directory will be an   integral part of normal administrative procedures within the   organization and must be defined and agreed upon in the initial   stages of development.6.9     Conclusion   Establishing a Directory service within an organization will involve   a great deal of cooperative effort. It is essential to get commitment   from the integral parties of an organization at the onset.  This   includes the technical, legal, and data managements components of the   organization.  Executive level commitment will make it much easier to   get the cooperation necessary.   Operational procedures must be clearly defined, as the inclusion in a   globally distributed service has wide visibility. Adherence to these   procedures must be maintained to the highest degree possible as   misinformation may result in unintentional legal violations and   unreliable access or data can adversely affect on a companys   reputation.   An X.500 Directory can be extremely useful for an organization if it   operates as designed. It may serve as the "hub" of the information   routing and the basis for several everyday activities. A successful   service will be one of the most important tools for communication in   the computer network environment. For people to make use of the   service, they must be able to rely on consistent and accurate   information.Jennings                     Informational                     [Page 17]

RFC 1943     Building an X.500 Directory Service in the US      May 1996References   1.      CCITT Blue Book, Volume VIII - Fascicle VIII.8, November 1988.   2.RFC 1632; A Revised Catalog of Available X.500           Implementations. A. Getchell; ESnet, S.           Sataluri; AT&T.   3.RFC 1274; The COSINE and Internet X.500 Schema. P. Barker &           S. Kille.   4.      CCITT Blue Book, Volume VIII - Fascicle VIII - Rec. X.509,           November 1988.   5.RFC 1295; User Bill of Rights for entries and listing in the           Public Directory. Networking Working Group; IETF, January           1992.   6.      STD 35,RFC 1355; Privacy and Accuracy Issues in Network           Information Center Databases. Curran, Marine, August 1992.   7.RFC 1006, ISO Transport Class 2 Non-use of Explicit Flow           Control over TCPRFC 1006 extension. Y. Pouffary, June 1995.   8.      Colin Robbins, NEXOR Ltd., Nottingham, London.           c.robbins@nexor.co.uk   9.      InterNIC; Collaborative effort of AT&T and           Network Solutions; info@internic.net   10.     ESnet; Managed and funded by the US Department of Energys           Energy Research Office in Scientific Computing (DOE/ER/OSC).   11.RFC 1777; Lightweight Directory Access Protocol, W. Yeong,           T. Howes, S. Kille, March 1995.   12.     Building a Directory Service, Final Report test phase SURFnet           X.500 pilot project, June 1995.   13.     The X.500 Directory Services: a discussion of the concerns           raised by the existence of a global Directory, Julia M. Hill,           Vol.2/No.1 Electronic Networking, Spring 1992.   14.     Directory Services and Privacy Issues, E. Jeunik and E.           Huizer.Jennings                     Informational                     [Page 18]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   15.     The Little Black Book; Mail Bonding with OSI Directory           Services, Marshall T. Rose, Simon & Schuster Company,           1992.   16.     NYSERNet White Pages Pilot Project: Status Report; NYSERNet           Technical Report #89-12-31-1, Marshall T. Rose, December 1989.   17.RFC 1798, Connection-less Lightweight Directory Access           Protocol, A. Young, June 1995.   18.RFC 1781; Using the OSI Directory to Achieve User Friendly           Naming, S. Kille, March 1995.   19.draft-ietf-pds-iwps-design-spec-01.txt, Tony Genovese;           Microsoft, Work in Progress, July 1995.   20.draft-ietf-ids-privacy-00.txt, B. Jennings; Sandia National           Laboratories, S. Sataluri; AT&T, Work in Progress, November           1994.Glossary   ACL     Access Control List; a mechanism to restrict access to data           stored in an X.500 Directory Service   Attribute       A collection of attributes belong to an entry in the                   Directory Service, and contain information belonging                   to that entry.   c=      countryName; Object class definition, specifies a country.           When used as part of the directory name, it identifies the           country in which the named object is physically located.   cn=     commonName; Attribute defining common name for individuals           included in a directory. In 1988 standards can be up to 64           characters.   CCITT   The International Telegraph and Telephone Consultative           Committee.   DAP     Directory Access Protocol; the protocol between a DUA and a           DSA.   DIB     Directory Information Base; a collection of information           objects in the Directory.   DIT     Directory Information Tree; the hierarchy of the distributed           database that makes up an X.500 service.Jennings                     Informational                     [Page 19]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   DSA     Directory System Agent; an application that offers the           Directory service, this is the database for the Directory.   DUA     Directory User Agent; an application that facilitates User           access to a DSA.   E-Mail  Electronic Mail.  Entry A Directory Service contains entries           on people, organizations, countries, etc. Entries belong to a           certain class, and information on entries is stored in           attributes.   ESnet   Energy Sciences Network; nationwide computer data           communications network.   GUI     Graphical User Interface.   IETF    Internet Engineering Task Force; an internationally           represented task force charged with solving the short-term           needs of the Internet   Internet        A collection of connected networks, international,                   running the Internet suite of protocols.   InterNIC        Directory of Directories, a collaborative project                   between AT&T, and Network Solutions, Inc.   IP      Internet Protocol; the network protocol offering a           conectionless-mode network service in the Internet suite of           protocols.   ISODE   ISO Development Environment, a research tool developed to           study the upper-layers of OSI and deploy network applications           according to the ISO OSI standards and ITU X series of           recommendations.   ITU     International Telecommunication Union; formerly the CCITT.   LDAP    Lightweight Directory Access Protocol, an Internet Standard           for a lightweight version of DAP running over TCP/IP.   Object  Entries in a Directory Service belong to an Object Class to           Class indicate the type and characteristic; e.g. Object Class           "person".   OSI     Open Standards Interconnection, An international           standardization program, facilitated by ISO and ITU to develop           standards for data networking.Jennings                     Informational                     [Page 20]

RFC 1943     Building an X.500 Directory Service in the US      May 1996   o=      organization; An attribute defining the company or           organization that the person works for.   ou=     organizational unit; An attribute found under organization.           Denotes the department, division, or other such sub-unit of           the organization that the person works in.   PEM     Privacy Enhanced Mail; and Internet Standard for sending           secure Electronic mail.   PSI     Performance Systems International, Inc.; operator of the           Internet White Pages Project   QUIPU   X.500 Directory implementation developed by Colin Robbins           while at the University College of London.   RDN     Relative Distinguished Name; a unique identifier for each list           subject, defined by the hierarchy of the DSA.   RFC     Request For Comments; Internet series publications   sn=     surname; Attribute defining the surname of the person in the           directory.   TCP/IP  Transmission Control Protocol and Internet Protocol; two           internet protocols.   White-Pages     Electronic directory, accessible via Internet suite of                   protocols.   Whois   An Internet standard protocol.   Whois++ An Internet Directory Services protocol; a possible           alternative for X.500 WPS   White Pages Service a Directory Service that contains information on                       people and organizations.   X.500   A series of recommendations as defined by the ITU, that           specify a Directory Services protocol.Jennings                     Informational                     [Page 21]

RFC 1943     Building an X.500 Directory Service in the US      May 19969.0 Security Considerations   Security issues are not discussed in this memo.Author's Address   Barbara Jennings   Sandia National Laboratories   Scientific Computing Systems   P.O. Box 5800   M/S 0807   Albuquerque, NM  87106   USA   Phone:  505-845-8554   Fax:    505-844-2067   EMail:  jennings@sandia.govJennings                     Informational                     [Page 22]