On most websites, when the user is about to provide the username and password to log into the system, there's a checkbox like "Stay logged in". If you check the box, it will keep you logged in across all sessions from the same web browser. How can I implement the same in Java EE?
I'm using FORM based container managed authentication with a JSF login page.
<security-constraint>
<display-name>Student</display-name>
<web-resource-collection>
<web-resource-name>CentralFeed</web-resource-name>
<description/>
<url-pattern>/CentralFeed.jsf</url-pattern>
</web-resource-collection>
<auth-constraint>
<description/>
<role-name>STUDENT</role-name>
<role-name>ADMINISTRATOR</role-name>
</auth-constraint>
</security-constraint>
<login-config>
<auth-method>FORM</auth-method>
<realm-name>jdbc-realm-scholar</realm-name>
<form-login-config>
<form-login-page>/index.jsf</form-login-page>
<form-error-page>/LoginError.jsf</form-error-page>
</form-login-config>
</login-config>
<security-role>
<description>Admin who has ultimate power over everything</description>
<role-name>ADMINISTRATOR</role-name>
</security-role>
<security-role>
<description>Participants of the social networking Bridgeye.com</description>
<role-name>STUDENT</role-name>
</security-role>
If you're on Java EE 8 or newer, put @RememberMe on a custom HttpAuthenticationMechanism along with a RememberMeIdentityStore.
@ApplicationScoped
@AutoApplySession
@RememberMe
public class CustomAuthenticationMechanism implements HttpAuthenticationMechanism {
@Inject
private IdentityStore identityStore;
@Override
public AuthenticationStatus validateRequest(HttpServletRequest request, HttpServletResponse response, HttpMessageContext context) {
Credential credential = context.getAuthParameters().getCredential();
if (credential != null) {
return context.notifyContainerAboutLogin(identityStore.validate(credential));
}
else {
return context.doNothing();
}
}
}
public class CustomIdentityStore implements RememberMeIdentityStore {
@Inject
private UserService userService; // This is your own EJB.
@Inject
private LoginTokenService loginTokenService; // This is your own EJB.
@Override
public CredentialValidationResult validate(RememberMeCredential credential) {
Optional<User> user = userService.findByLoginToken(credential.getToken());
if (user.isPresent()) {
return new CredentialValidationResult(new CallerPrincipal(user.getEmail()));
}
else {
return CredentialValidationResult.INVALID_RESULT;
}
}
@Override
public String generateLoginToken(CallerPrincipal callerPrincipal, Set<String> groups) {
return loginTokenService.generateLoginToken(callerPrincipal.getName());
}
@Override
public void removeLoginToken(String token) {
loginTokenService.removeLoginToken(token);
}
}
You can find a real world example in the Java EE Kickoff Application.
If you're on Java EE 6 or 7, homegrow a long-living cookie to track the unique client and use the Servlet 3.0 API provided programmatic login HttpServletRequest#login() when the user is not logged-in but the cookie is present.
This is the easiest to achieve if you create another DB table with a java.util.UUID value as PK and the ID of the user in question as FK.
Assume the following login form:
<form action="login" method="post">
<input type="text" name="username" />
<input type="password" name="password" />
<input type="checkbox" name="remember" value="true" />
<input type="submit" />
</form>
And the following in doPost() method of a Servlet which is mapped on /login:
String username = request.getParameter("username");
String password = hash(request.getParameter("password"));
boolean remember = "true".equals(request.getParameter("remember"));
User user = userService.find(username, password);
if (user != null) {
request.login(user.getUsername(), user.getPassword()); // Password should already be the hashed variant.
request.getSession().setAttribute("user", user);
if (remember) {
String uuid = UUID.randomUUID().toString();
rememberMeService.save(uuid, user);
addCookie(response, COOKIE_NAME, uuid, COOKIE_AGE);
} else {
rememberMeService.delete(user);
removeCookie(response, COOKIE_NAME);
}
}
(the COOKIE_NAME should be the unique cookie name, e.g. "remember" and the COOKIE_AGE should be the age in seconds, e.g. 2592000 for 30 days)
Here's how the doFilter() method of a Filter which is mapped on restricted pages could look like:
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) res;
User user = request.getSession().getAttribute("user");
if (user == null) {
String uuid = getCookieValue(request, COOKIE_NAME);
if (uuid != null) {
user = rememberMeService.find(uuid);
if (user != null) {
request.login(user.getUsername(), user.getPassword());
request.getSession().setAttribute("user", user); // Login.
addCookie(response, COOKIE_NAME, uuid, COOKIE_AGE); // Extends age.
} else {
removeCookie(response, COOKIE_NAME);
}
}
}
if (user == null) {
response.sendRedirect("login");
} else {
chain.doFilter(req, res);
}
In combination with those cookie helper methods (too bad they are missing in Servlet API):
public static String getCookieValue(HttpServletRequest request, String name) {
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (name.equals(cookie.getName())) {
return cookie.getValue();
}
}
}
return null;
}
public static void addCookie(HttpServletResponse response, String name, String value, int maxAge) {
Cookie cookie = new Cookie(name, value);
cookie.setPath("/");
cookie.setMaxAge(maxAge);
response.addCookie(cookie);
}
public static void removeCookie(HttpServletResponse response, String name) {
addCookie(response, name, null, 0);
}
Although the UUID is extremely hard to brute-force, you could provide the user an option to lock the "remember" option to user's IP address (request.getRemoteAddr()) and store/compare it in the database as well. This makes it a tad more robust. Also, having an "expiration date" stored in the database would be useful.
It's also a good practice to replace the UUID value whenever the user has changed its password.
Please, upgrade.