create or replace function authenticate_aduser(
	p_username		in		varchar2,
	p_password		in		varchar2)
return boolean 
is
	l_user			varchar2(256);
	l_ldap_server	varchar2(256)	:= '<ldap_server_hostname>';
	l_domain		varchar2(256)	:= '<domain name>';
	l_ldap_port		number			:= 389;
	l_retval		pls_integer;
	l_session		dbms_ldap.session;
	l_cnt			number;
begin
	l_user			:= p_username||'@'||l_domain;
	l_session		:= dbms_ldap.init( l_ldap_server, l_ldap_port ); -- start session
	l_retval		:= dbms_ldap.simple_bind_s( l_session, l_user, p_password ); -- auth as user
	l_retval		:= dbms_ldap.unbind_s( l_session ); -- unbind
	return true;
exception when others then
	l_retval := dbms_ldap.unbind_s( l_session );
	return false;
end;
/