public boolean addUser(String username, String password) {
if (m_users.containsKey(username)) return false;
try {
String passwordHash = DigestUtil.digestString((password), "SHA");
User user;
if (m_forceUseJamesUser) {
user = new DefaultJamesUser(username, passwordHash, "SHA");
} else {
user = new DefaultUser(username, passwordHash, "SHA");