Directory Services 7.4.3

Glossary

Abandon operation

LDAP operation to stop processing of a request in progress, after which the server drops the connection without a reply to the client application.

Access control

Control to grant or to deny access to a resource.

Access control instruction (ACI)

Instruction added as a directory entry attribute for fine-grained control over what a given user or group member is authorized to do in terms of LDAP operations and access to user data.

ACIs are implemented independently from privileges, which apply to administrative operations.

Related: Privilege

Access control list (ACL)

An access control list connects a user or group of users to one or more security entitlements. For example, users in group sales are granted the entitlement read-only to some financial data.

Access log

Server log tracing the operations the server processes including timestamps, connection information, and information about the operation itself.

Account lockout

The act of making an account temporarily or permanently inactive after successive authentication failures.

Active user

A user that has the ability to authenticate and use the services, having valid credentials.

Add operation

LDAP operation to add a new entry or entries to the directory.

Anonymous

A user that does not need to authenticate, and is unknown to the system.

Anonymous bind

A bind operation using simple authentication with an empty DN and an empty password, allowing anonymous access such as reading public information.

Approximate index

Index is used to match values that "sound like" those provided in the filter.

Attribute

Properties of a directory entry, stored as one or more key-value pairs. Typical examples include the common name (cn) to store the user’s full name and variations of the name, user ID (uid) to store a unique identifier for the entry, and mail to store email addresses.

Attribute value assertion (AVA)

An attribute description and a matching rule assertion value for the attribute.

DS software uses AVAs in RDNs, and to determine whether an entry matches an assertion. For example, a search filter specifying the AVA uid=bjensen asserts that matching entries have a uid attribute value equal to bjensen.

Audit log

Type of access log that dumps changes in LDIF.

Authentication

The process of verifying who is requesting access to a resource; the act of confirming the identity of a principal.

Authorization

The process of determining whether access should be granted to an individual based on information about that individual; the act of determining whether to grant or to deny a principal access to a resource.

Backend

Repository that stores directory data. Different implementations with different capabilities exist.

Binary copy

Backup files from one replica are restored on another replica.

Bind operation

LDAP authentication operation to determine the client’s identity in LDAP terms, the identity which is later used by the server to authorize (or not) access to directory data that the client wants to lookup or change.

Branch

The distinguished name (DN) of a non-leaf entry in the Directory Information Tree (DIT), and that entry and all its subordinates taken together.

Some administrative operations allow you to include or exclude branches by specifying the DN of the branch.

Related: Suffix

Collective attribute

A standard mechanism for defining attributes that appear on all the entries in a particular subtree.

Compare operation

LDAP operation to compare a specified attribute value with the value stored on an entry in the directory.

Control

Information added to an LDAP message to further specify how an LDAP operation should be processed. DS supports many LDAP controls.

Change sequence number (CSN)

An opaque string uniquely identifying a single change to directory data. A CSN indicates exactly when a change occurred on which replica. An example CSN is 010f016df804edca0000008fevaluation-only.

DS replication uses CSNs to replay replicated operations consistently on all replicas. DS replicas record CSNs in historical data values for ds-sync-state and ds-sync-hist attributes.

When troubleshooting replication data consistency, it can be useful to interpret CSNs. Contact support for help.

Database cache

Memory space set aside to hold database content.

Delete operation

LDAP operation to remove an existing entry or entries from the directory.

Directory

A directory is a network service which lists participants in the network such as users, computers, printers, and groups. The directory provides a convenient, centralized, and robust mechanism for publishing and consuming information about network participants.

Directory hierarchy

A directory can be organized into a hierarchy in order to make it easier to browse or manage. Directory hierarchies normally represent something in the physical world, such as organizational hierarchies or physical locations.

For example, the top level of a directory may represent a company, the next level down divisions, the next level down departments, and down the hierarchy. Alternately, the top level may represent the world, the next level down countries, next states or provinces, and next cities.

Directory Information Tree (DIT)

A set of directory entries organized hierarchically in a tree structure, where the vertices are the entries, and the arcs between vertices define relationships between entries.

Directory object

A directory object is an item in a directory. Example objects include users, user groups, computers, and more. Objects may be organized into a hierarchy and contain identifying attributes.

Related: Entry

Directory proxy server

Server that forwards LDAP requests to remote directory servers. A standalone directory proxy server does not store user data.

Directory server

Server application for centralizing information about network participants. A highly available directory service consists of multiple directory servers configured to replicate directory data.

Related: Replication

Directory Services Markup Language (DSML)

Standard language to access directory services using XML. DMSL v1 defined an XML mapping of LDAP objects, while DSMLv2 maps the LDAP Protocol and data model to XML.

Directory superuser

Directory account with privileges to do full administration of the DS server, including bypassing access control evaluation, changing access controls, and changing administrative privileges.

Related: Superuser

Distinguished name (DN)

Fully qualified name for a directory entry, such as uid=bjensen,ou=People,dc=example,dc=com, built by concatenating the entry RDN (uid=bjensen) with the DN of the parent entry (ou=People,dc=example,dc=com).

Domain

A replication domain consists of several directory servers sharing the same synchronized set of data.

The base DN of a replication domain specifies the base DN of the replicated data.

DSML gateway

Standalone web application that translates DSML requests from client applications to LDAP requests to a directory service, and LDAP responses from a directory service to DSML responses to client applications.

Dynamic group

Group that specifies members using LDAP URLs.

Entry

An entry is an object in the directory, defined by one of more object classes, and their related attributes.

Entry cache

Memory space set aside to hold frequently accessed, large entries, such as static groups.

Equality index

Index used to match values that correspond exactly (though generally without case sensitivity) to the value provided in the search filter.

Errors log

Server log tracing server events, error conditions, and warnings, categorized and identified by severity.

Etime

Elapsed time within the server to process a request, starting from the moment the decoded operation is available to be processed by a worker thread.

Export

Save directory data in an LDIF file.

Extended operation

Additional LDAP operation not included in the original standards. DS servers support several standard LDAP extended operations.

Extensible match index

Index for a matching rule other than approximate, equality, ordering, presence, substring or VLV, such as an index for generalized time.

External user

An individual that accesses company resources or services but is not working for the company. Typically, a customer or partner.

Filter

An LDAP search filter is an expression that the server uses to find entries that match a search request, such as (mail=*@example.com) to match all entries having an email address in the example.com domain.

Group

Entry identifying a set of members whose entries are also in the directory.

Generation ID

The initial state identifier for a replicated directory server base DN. It is a hash of the first 1000 entries of the base DN, computed when creating the backend, importing data from LDIF, or initializing replication.

Replication can only proceed between base DNs that have the same generation ID.

HDAP

Short for HTTP Directory Access Protocol.

HDAP is not a standard. HDAP is the name of the feature providing REST APIs and HTTP access to directory data. HDAP translates HTTP requests to LDAP requests and LDAP responses to HTTP responses.

HDAP gateway

Standalone HDAP web application.

Idle time limit

Defines how long DS allows idle connections to remain open.

Import

Read in and index directory data from an LDIF file.

Inactive user

An entry in the directory that once represented a user but which is now no longer able to be authenticated.

Index

Directory server backend feature to allow quick lookup of entries based on their attribute values.

Index entry limit

When the number of entries that an index key points to exceeds the index entry limit, DS stops maintaining the list of entries for that index key.

Internal user

An individual who works within the company either as an employee or as a contractor.

LDAP Data Interchange Format (LDIF)

Standard, portable, text-based representation of directory content.

Refer to RFC 2849.

LDAP URL

LDAP Uniform Resource Locator, such as ldaps://ds.example.com:636/dc=example,dc=com??sub?(uid=bjensen).

Refer to RFC 2255.

LDAPS

LDAP over SSL.

Lightweight Directory Access Protocol (LDAP)

A simple and standardized network protocol used by applications to connect to a directory, search for objects and add, edit or remove objects.

Refer to RFC 4510.

Matching rule

Defines rules for performing matching operations against assertion values. Matching rules are frequently associated with an attribute syntax, and are used to compare values according to that syntax.

For example, the distinguishedNameEqualityMatch matching rule can be used to determine whether two DNs are equal and can ignore unnecessary spaces around commas and equal signs, differences in capitalization in attribute names, and other discrepancies.

Modify DN operation

LDAP modification operation to request that the server change the distinguished name of an entry.

Modify operation

LDAP modification operation to request that the server change one or more attributes of an entry.

Naming context

Base DN under which client applications can look for user data.

Object class

Identifies entries that share certain characteristics. Most commonly, an entry’s object classes define the attributes that must and may be present on the entry.

Object classes are stored on entries as values of the objectClass attribute. Object classes are defined in the directory schema, and can be abstract (defining characteristics for other object classes to inherit), structural (defining the basic structure of an entry, one structural inheritance per entry), or auxiliary (for decorating entries already having a structural object class with other required and optional attributes).

Object identifier (OID)

String that uniquely identifies an object, such as 0.9.2342.19200300.100.1.1 for the user ID attribute or 1.3.6.1.4.1.1466.115.121.1.15 for DirectoryString syntax.

Operational attribute

An attribute that has a special (operational) meaning for the server, such as pwdPolicySubentry or modifyTimestamp.

Ordering index

Index used to match values for a filter that specifies a range.

Password policy

A set of rules regarding what sequence of characters constitutes an acceptable password. Acceptable passwords are generally those that would be too difficult for another user, or an automated program to guess and thereby defeat the password mechanism.

Password policies may require a minimum length, a mixture of different types of characters (lowercase, uppercase, digits, punctuation marks, and other characters), avoiding dictionary words or passwords based on the user’s name, and other attributes.

Password policies may also require that users not reuse old passwords and that users change their passwords regularly.

Password reset

Password change performed by a user other than the user who owns the entry.

Password storage scheme

Mechanism for encoding user passwords stored on directory entries. DS implements a number of password storage schemes.

Password validator

Mechanism for determining whether a proposed password is acceptable for use. DS implements a number of password validators.

Plugin

Java library with accompanying configuration that implements a feature through processing that is not essential to the core operation of DS servers.

As the name indicates, plugins can be plugged in to an installed server for immediate configuration and use without recompiling the server.

DS servers invoke plugins at specific points in the lifecycle of a client request. The DS configuration framework lets directory administrators manage plugins with the same tools used to manage the server.

Presence index

Index used to match the fact that an attribute is present on the entry, regardless of the value.

Principal

Entity that can be authenticated, such as a user, a device, or an application.

Privilege

Server configuration settings controlling access to administrative operations such as exporting and importing data, restarting the server, performing password reset, and changing the server configuration.

Privileges are implemented independently from access control instructions (ACI), which apply to LDAP operations and user data.

Referential integrity

Ensuring that group membership remains consistent following changes to member entries.

Referint log

Server log tracing referential integrity events, with entries similar to the errors log.

Referral

Reference to another directory location, which can be another directory server running elsewhere or another container on the same server, where the current operation can be processed.

Relative distinguished name (RDN)

Initial portion of a DN that distinguishes the entry from all other entries at the same level, such as uid=bjensen in uid=bjensen,ou=People,dc=example,dc=com.

Replica

Directory server this is configured to use replication.

Replication

Data synchronization that ensures all directory servers participating eventually share a consistent set of directory data.

Replication server

Server dedicated to transmitting replication messages. A standalone replication server does not store user data.

Root DSE

The directory entry with distinguished name "" (empty string), where DSE is an acronym for DSA-Specific Entry. DSA is an acronym for Directory Server Agent, a single directory server.

The root DSE serves to expose information over LDAP about what the directory server supports in terms of LDAP controls, auth password schemes, SASL mechanisms, LDAP protocol versions, naming contexts, features, LDAP extended operations, and other information.

Schema

LDAP schema defines the object classes, attributes types, attribute value syntaxes, matching rules and other constrains on entries held by the directory server.

Search filter

Refer to: Filter

Search operation

LDAP lookup operation where a client requests that the server return entries based on an LDAP filter, and a base DN under which to search.

Simple authentication

Bind operation performed with a user’s entry DN and user’s password.

Use simple authentication only if the network connection is secure.

Size limit

Sets the maximum number of entries returned for a search.

Static group

Group that enumerates member entries.

Subentry

An entry, such as a password policy entry, that resides with the user data but holds operational data, and is not visible in search results unless explicitly requested.

Substring index

Index used to match values specified with wildcards in the filter.

Suffix

The distinguished name (DN) of a root entry in the Directory Information Tree (DIT), and that entry and all its subordinates taken together as a single object of administrative tasks such as export, import, indexing, and replication.

Superuser

User with privileges to perform unconstrained administrative actions on DS server. This account is analogous to the Linux root and Windows Administrator accounts.

The conventional default superuser DN is uid=admin. You can create additional superuser accounts, each with different administrative privileges.

Superuser privileges include the following:

  • bypass-acl: The holder is not subject to access control.

  • privilege-change: The holder can edit administrative privileges.

  • proxied-auth: The holder can make requests on behalf of another user, including directory superusers.

Task

Mechanism to provide remote access to server administrative functions.

DS software supports tasks to back up and restore backends, to import and export LDIF files, and to stop and restart the server.

Time limit

Defines the maximum processing time DS devotes to a search operation.

Unbind operation

LDAP operation to release resources at the end of a session.

Unindexed search

Search operation for which no matching index is available.

If no indexes are applicable, then the directory server potentially has to go through all entries to look for candidate matches. For this reason, the unindexed-search privilege, which allows users to request searches for which no applicable index exists, is reserved for the directory manager by default.

User

An entry that represents an individual that can be authenticated through credentials contained or referenced by its attributes. A user may represent an internal user or an external user, and may be an active user or an inactive user.

User attribute

An attribute for storing user data on a directory entry such as mail or givenname.

Virtual attribute

An attribute with dynamically generated values that appear in entries but are not persistently stored in the backend.

Virtual directory

An application that exposes a consolidated view of multiple physical directories over an LDAP interface. Consumers of the directory information connect to the virtual directory’s LDAP service.

Behind the scenes, requests for information and updates to the directory are sent to one or more physical directories where the actual information resides. Virtual directories enable organizations to create a consolidated view of information that for legal or technical reasons cannot be consolidated into a single physical copy.

Virtual list view (VLV) index

Browsing index designed to help the directory server respond to client applications that need, for example, to browse through a long list of results a page at a time in a GUI.

Virtual static group

DS group that lets applications get dynamic groups represented as static groups.

X.500

A family of standardized protocols for accessing, browsing and maintaining a directory. X.500 is functionally similar to LDAP, but is generally considered to be more complex, and has consequently not been widely adopted.