Spring Security authentication via URL

Question

I have a Spring MVC app that uses Spring Security and form based login for authorization/authentication.

Now I want to add a special URL that includes a token that should be accessible without additional information because the token is unique to a user:

http://myserver.com/special/5f6be0c0-87d7-11e2-9e96-0800200c9a66/text.pdf

How do I need to configure Spring Security to use that token for user authentication?

Answer 1

You can provide a custom PreAuthenticatedProcessingFilter and PreAuthenticatedAuthenticationProvider. See Pre-Authentication Scenarios chapter for details.

Answer 2

You need to define your custom pre auth filter.

In security app context within http tag:

<custom-filter position="PRE_AUTH_FILTER" ref="preAuthTokenFilter" />

Then define your filter bean (and its properties approprietly):

<beans:bean class="com.yourcompany.PreAuthTokenFilter"
      id="preAuthTokenFilter">
    <beans:property name="authenticationDetailsSource" ref="authenticationDetailsSource" />
    <beans:property name="authenticationManager" ref="authenticationManager" />
    <beans:property name="authenticationEntryPoint" ref="authenticationEntryPoint"/>
</beans:bean>

Create your custom filter extended from GenericFilterBean

public class PreAuthTokenFilter extends GenericFilterBean {

private AuthenticationEntryPoint authenticationEntryPoint;
private AuthenticationManager authenticationManager;
private AuthenticationDetailsSource authenticationDetailsSource = new WebAuthenticationDetailsSource();

@Override
public void doFilter(ServletRequest req, ServletResponse resp,
                     FilterChain chain) throws IOException, ServletException {
    HttpServletRequest request = (HttpServletRequest) req;
    HttpServletResponse response = (HttpServletResponse) resp;

    String token = getTokenFromHeader(request);//your method

    if (StringUtils.isNotEmpty(token)) {
        /* get user entity from DB by token, retrieve its username and password*/

        if (isUserTokenValid(/* some args */)) {
            try {
                UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password);
                authRequest.setDetails(this.authenticationDetailsSource.buildDetails(request));
                Authentication authResult = this.authenticationManager.authenticate(authRequest);
                SecurityContextHolder.getContext().setAuthentication(authResult);
            } catch (AuthenticationException e) {
            }
        }
    }

    chain.doFilter(request, response);
}

/*
other methods
*/

If you don't want or cannot retrieve a password, you need to create your own AbstractAuthenticationToken which will receive only username as param (principal) and use it instead of UsernamePasswordAuthenticationToken:

public class PreAuthToken extends AbstractAuthenticationToken {

    private final Object principal;

    public PreAuthToken(Object principal) {
        super(null);
        super.setAuthenticated(true);
        this.principal = principal;
    }

    @Override
    public Object getCredentials() {
        return "";
    }

    @Override
    public Object getPrincipal() {
        return principal;
    }
}

Answer 3

I ran into this problem, and solved it using a custom implementation of the Spring Security RembereMe Service infrastructure. Here is what you need to do.

• Define your own Authentication object

  public class LinkAuthentication extends AbstractAuthenticationToken { @Override public Object getCredentials() { return null; }

  @Override
  public Object getPrincipal()
  {
  
      return the prncipal that that is passed in via the constructor 
  }
  

  }

Define

public class LinkRememberMeService implements RememberMeServices, LogoutHandler
{    
    /**
     * It might appear that once this method is called and returns an authentication object, that authentication should be finished and the
     * request should proceed. However, spring security does not work that way.
     * 
     * Once this method returns a non null authentication object, spring security still wants to run it through its authentication provider
     * which, is totally brain dead on the part of Spring this, is why there is also a
     * LinkAuthenticationProvider
     * 
     */
    @Override
    public Authentication autoLogin(HttpServletRequest request, HttpServletResponse response)
    {
        String accessUrl = ServletUtils.getApplicationUrl(request, "/special/");
        String requestUrl = request.getRequestURL().toString();
        if (requestUrl.startsWith(accessUrl))
        {
            // take appart the url extract the token, find the user details object 
                    // and return it. 
            LinkAuthentication linkAuthentication = new LinkAuthentication(userDetailsInstance);
            return linkAuthentication;
        } else
        {
            return null;
        }
    }

    @Override
    public void loginFail(HttpServletRequest request, HttpServletResponse response)
    {
    }

    @Override
    public void loginSuccess(HttpServletRequest request, HttpServletResponse response, Authentication successfulAuthentication)
    {
    }

    @Override
    public void logout(HttpServletRequest request, HttpServletResponse response, Authentication authentication)
    {
    }
}


public class LinkAuthenticationProvider implements AuthenticationProvider
{

    @Override
    public Authentication authenticate(Authentication authentication) throws AuthenticationException
    {
        // Spring Security is totally brain dead and over engineered
        return authentication;
    }

    @Override
    public boolean supports(Class<?> authentication)
    {
        return LinkAuthentication.class.isAssignableFrom(authentication);
    }

}

Hack up the rest rest of your spring security xml to define a custom authentication provider, and the custom remember me service.

P.S. if you do base64 encoding of the GUID in your URL it will be a few characters shorter. You can use the Apache commons codec base64 binary encoder / decoder to do safer url links.

public static String toBase64Url(UUID uuid)
{
    return Base64.encodeBase64URLSafeString(toBytes(uuid));
}