LDAP search filter expressions

The rules for rule-based user groups are based on the LDAP search filter syntax.

For information about the LDAP search filter syntax, see RFC2254 - The String Representation of LDAP Search Filters in the related links section.

We can use this subset of the LDAP search filter syntax:

• The AND operator represented by an ampersand (&).

• The OR operator represented by a vertical slash (|).

• The NOT operator represented by an exclamation mark (!).

• Equality comparison represented by an equal sign (=) for name and value expressions.

• Wildcards represented by an asterisk (*) at the beginning or end of values in name and value expressions.

Attributes must not start with one of the operator symbols AND, OR, or NOT (&, |, or !), and they must not contain a comparison equal sign (=), or parentheses.

For example:

(uid=testuser)

Matches to all users that have exactly the value testuser for the attribute uid.

(uid=test*)

Matches to all users that have values for the attribute uis that start with test.

(!(uid=test*))

Matches to all users that have values for the attribute uidthat do not start with test.

(&(department=1234)(city=Paris))

Matches to all users that have exactly the value 1234 for the attribute department and exactly the value Paris for the attribute city .

(|(department=1234)(department=56*))

Matches to all users that have exactly the value 1234 or a value that starts with 56 for the attribute department.

(&(department=12*)(!(department=123*)))

Matches to all users that have a value starting with 12, but not starting with 123 for the attribute department.

Syntax validation

When we define or modify a rule base user group, the rule-based user groups adapter validates the syntax for the LDAP search filter expression.

For example:

Invalid rule specified:

If you provide a rulthat is not valid, rule-based user groups return the appropriate error message. However, it does not check whether the attribute names that we use exist in the user configuration. We can verify the configuration using the code that calls the search filter.

Invalid attribute specified:

If an invalid attribute name is contained in a rule, the group membership determination for rule-based user groups does not work and logs an error. Existing rules might break if the attribute configuration in the system changes, for example, when an attribute is removed or renamed.

Parent: Rule-based user groups
Related:

RFC2254 - The String Representation of LDAP Search Filters - http://www.faqs.org/rfcs/rfc2254.html