SampleOAuthProvider.java

package evanq.game.auth.provider;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Properties;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.codec.digest.DigestUtils;

import net.oauth.OAuthAccessor;
import net.oauth.OAuthConsumer;
import net.oauth.OAuthException;
import net.oauth.OAuthMessage;
import net.oauth.OAuthProblemException;
import net.oauth.OAuthValidator;
import net.oauth.SimpleOAuthValidator;
import net.oauth.server.OAuthServlet;

/**
 * Utility methods for providers that store consumers, tokens and secrets in 
 * local cache (HashSet). Consumer key is used as the name, and its credentials are 
 * stored in HashSet.
 *
 * @author Praveen Alavilli
 */
public class SampleOAuthProvider {

    public static final OAuthValidator VALIDATOR = new SimpleOAuthValidator();

    private static final Map<String, OAuthConsumer> ALL_CONSUMERS 
                    = Collections.synchronizedMap(new HashMap<String,OAuthConsumer>(10));
    
    private static final Collection<OAuthAccessor> ALL_TOKENS = new HashSet<OAuthAccessor>();

    private static Properties consumerProperties = null;

    public static synchronized void loadConsumers(
            ServletConfig config) throws IOException {
        Properties p = consumerProperties;
        if (p == null) {
            p = new Properties();
            String resourceName = "/"
                    + SampleOAuthProvider.class.getPackage().getName().replace(
                    ".", "/") + "/provider.properties";
            URL resource = SampleOAuthProvider.class.getClassLoader()
            .getResource(resourceName);
            if (resource == null) {
                throw new IOException("resource not found: " + resourceName);
            }
            InputStream stream = resource.openStream();
            try {
                p.load(stream);
            } finally {
                stream.close();
            }
        }
        consumerProperties = p;
        
        // for each entry in the properties file create a OAuthConsumer
        for(Map.Entry prop : p.entrySet()) {
            String consumer_key = (String) prop.getKey();
            // make sure it's key not additional properties
            if(!consumer_key.contains(".")){
                String consumer_secret = (String) prop.getValue();
                if(consumer_secret != null){
                    String consumer_description = (String) p.getProperty(consumer_key + ".description");
                    String consumer_callback_url =  (String) p.getProperty(consumer_key + ".callbackURL");
                    // Create OAuthConsumer w/ key and secret
                    OAuthConsumer consumer = new OAuthConsumer(
                            consumer_callback_url, 
                            consumer_key, 
                            consumer_secret, 
                            null);
                    consumer.setProperty("name", consumer_key);
                    consumer.setProperty("description", consumer_description);
                    ALL_CONSUMERS.put(consumer_key, consumer);
                }
            }
        }
        
    }

    public static synchronized OAuthConsumer getConsumer(
            OAuthMessage requestMessage)
            throws IOException, OAuthProblemException {
        
        OAuthConsumer consumer = null;
        // try to load from local cache if not throw exception
        String consumer_key = requestMessage.getConsumerKey();
        
        consumer = SampleOAuthProvider.ALL_CONSUMERS.get(consumer_key);
        
        if(consumer == null) {
            OAuthProblemException problem = new OAuthProblemException("token_rejected");
            throw problem;
        }
        
        return consumer;
    }
    
    /**
     * Get the access token and token secret for the given oauth_token. 
     */
    public static synchronized OAuthAccessor getAccessor(OAuthMessage requestMessage)
            throws IOException, OAuthProblemException {
        
        // try to load from local cache if not throw exception
        String consumer_token = requestMessage.getToken();
        OAuthAccessor accessor = null;
        for (OAuthAccessor a : SampleOAuthProvider.ALL_TOKENS) {
            if(a.requestToken != null) {
                if (a.requestToken.equals(consumer_token)) {
                    accessor = a;
                    break;
                }
            } else if(a.accessToken != null){
                if (a.accessToken.equals(consumer_token)) {
                    accessor = a;
                    break;
                }
            }
        }
        
        if(accessor == null){
            OAuthProblemException problem = new OAuthProblemException("token_expired");
            throw problem;
        }
        
        return accessor;
    }

    /**
     * Set the access token 
     */
    public static synchronized void markAsAuthorized(OAuthAccessor accessor, String userId)
            throws OAuthException {
        
        
        // first remove the accessor from cache
        ALL_TOKENS.remove(accessor);
        
        accessor.setProperty("user", userId);   
        accessor.setProperty("authorized", Boolean.TRUE);
        
        // update token in local cache
        ALL_TOKENS.add(accessor);
    }
    

    /**
     * Generate a fresh request token and secret for a consumer.
     * 
     * @throws OAuthException
     */
    public static synchronized void generateRequestToken(
            OAuthAccessor accessor)
            throws OAuthException {

        // generate oauth_token and oauth_secret
        String consumer_key = (String) accessor.consumer.getProperty("name");
        // generate token and secret based on consumer_key
        
        // for now use md5 of name + current time as token
        String token_data = consumer_key + System.nanoTime();
        String token = DigestUtils.md5Hex(token_data);
        // for now use md5 of name + current time + token as secret
        String secret_data = consumer_key + System.nanoTime() + token;
        String secret = DigestUtils.md5Hex(secret_data);
        
        accessor.requestToken = token;
        accessor.tokenSecret = secret;
        accessor.accessToken = null;
        
        // add to the local cache
        ALL_TOKENS.add(accessor);
        
    }
    
    /**
     * Generate a fresh request token and secret for a consumer.
     * 
     * @throws OAuthException
     */
    public static synchronized void generateAccessToken(OAuthAccessor accessor)
            throws OAuthException {

        // generate oauth_token and oauth_secret
        String consumer_key = (String) accessor.consumer.getProperty("name");
        // generate token and secret based on consumer_key
        
        // for now use md5 of name + current time as token
        String token_data = consumer_key + System.nanoTime();
        String token = DigestUtils.md5Hex(token_data);
        // first remove the accessor from cache
        ALL_TOKENS.remove(accessor);
        
        accessor.requestToken = null;
        accessor.accessToken = token;
        
        // update token in local cache
        ALL_TOKENS.add(accessor);
    }

    public static void handleException(Exception e, HttpServletRequest request,
            HttpServletResponse response, boolean sendBody)
            throws IOException, ServletException {
        String realm = (request.isSecure())?"https://":"http://";
        realm += request.getLocalName();
        OAuthServlet.handleException(response, e, realm, sendBody); 
    }

}