Designing Access Control - Red Hat DIRECTORY SERVER 8.1 - DEPLOYMENT Deployment Manual

The lockout policy works in conjunction with the password policy to provide further security. The
account lockout feature protects against crackers who try to break into the directory by repeatedly
trying to guess a user's password. A specific user can be locked out of the directory after a given
number of failed attempts to bind.
8.6.4. Designing a Password Policy in a Replicated Environment
Password and account lockout policies are enforced in a replicated environment as follows:
• Password policies are enforced on the data master.
• Account lockout is enforced on all servers in the replication setup.
The password policy information in the directory, such as password age, the account lockout counter,
and the expiration warning counter, are all replicated. The configuration information, however, is
stored locally and is not replicated. This information includes the password syntax and the history of
password modifications.
When configuring a password policy in a replicated environment, consider the following points:
• All replicas issue warnings of an impending password expiration. This information is kept locally
on each server, so if a user binds to several replicas in turn, the user receives the same warning
several times. In addition, if the user changes the password, it may take time for this information to
filter through to the replicas. If a user changes a password and then immediately rebinds, the bind
may fail until the replica registers the changes.
• The same bind behavior should occur on all servers, including suppliers and replicas. Always create
the same password policy configuration information on each server.
• Account lockout counters may not work as expected in a multi-master environment.

8.7. Designing Access Control

After deciding on the authentication schemes to use to establish the identity of directory clients, decide
how to use those schemes to protect the information contained in the directory. Access control can
specify that certain clients have access to particular information, while other clients do not.
Access control is defined using one or more access control lists (ACLs). The directory's ACLs consist
of a series of one or more access control information (ACI) statements that either allow or deny
permissions (such as read, write, search, and compare) to specified entries and their attributes.
Using the ACL, permissions can be set at any level of the directory tree:
• The entire directory.
• A particular subtree of the directory.
• Specific entries in the directory.
• A specific set of entry attributes.
• Any entry that matches a given LDAP search filter.
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