This parameter can be used with UseSSL or
UseTLS parameters to control how LDAP server's
certificate is verified. The options are:
noneNo server certificate is required, and if
the server supplies a certificate it is not checked.
optionalVerify if the server offers a
certificate.
requireThe server must provide a certificate,
and it must be valid.
The default value is require. Format
specifiers, such as %{GlobalVar:name}, are evaluated
when the configuration is loaded.
Tip
require is the most secure
option.