Overview#
Attribute Value Assertion (AVA) in LDAP is a combination of an Attribute-Names and an Attribute Value.Attribute Value Assertion contains an Attribute-Name and a matching Rule Assertion Value suitable for that type. RFC 4511
The Assertion Value is used in conjunction with a matchingRule in order to make the match determination:
- If the matching Rule is an equality matching rule, then it will be used to determine whether the attribute contains a given value.
- If it is an ordering matching rule, then the Attribute Value Assertion will be used to determine whether the attribute contains a value that is greater than or equal to, or less than or equal to, the assertion value.
- If it is an approximate matching rule, then the Attribute Value Assertion will be used to determine whether the attribute contains a value that is approximately equal to the assertion value.
- Substring matching is more complex and uses a Substring Assertion rather than a simple Attribute Value Assertion.
Attribute Value Assertion are used in Compare Request, as well as LDAP SearchFilters:
- Equality SearchFilter
- Greater-Or-Equal SearchFilter
- LessThan-Or-Equal SearchFilter
- approximate match