Update README.md

changes to support single-sign-on (sso)

README.md

@@ -14,15 +14,31 @@ Going forward, we no need to enable sticky session (JSESSIONID) in Load Balancer
    - Apache Tomcat 7
    - Apache Tomcat 8
    - Apache Tomcat 9
+   - Apache Tomcat 10
 
-## Downloads:
-   - [latest version (3.0.3)](https://github.com/ran-jit/tomcat-cluster-redis-session-manager/releases/tag/3.0.3)
+## Downloads: [![Total Downloads](https://img.shields.io/github/downloads/ran-jit/tomcat-cluster-redis-session-manager/total.svg)](https://github.com/ran-jit/tomcat-cluster-redis-session-manager/wiki)
+   - [latest version (4.0)](https://github.com/ran-jit/tomcat-cluster-redis-session-manager/releases/tag/4.0)
    - [older versions](https://github.com/ran-jit/tomcat-cluster-redis-session-manager/wiki)
 
 <p align="center">
-	<a href="https://paypal.me/ranmanic1" target="_blank"><img alt="Donate" height="30%" width="30%" src="https://github.com/ran-jit/tomcat-cluster-redis-session-manager/blob/master/src/main/resources/donate.png"></a>
+  <a href="https://www.buymeacoffee.com/ranmanic" target="_blank"><img src="https://cdn.buymeacoffee.com/buttons/v2/default-red.png" alt="Buy Me A Coffee" style="height: 60px !important;width: 217px !important;" ></a>
 </p>
 
+## Maven configuration
+```
+<repository>
+  <id>repsy</id>
+  <name>tomcat-cluster-redis-session-manager-repo</name>
+  <url>https://repo.repsy.io/mvn/ranmanic/tomcat-session-manager</url>
+</repository>
+
+<dependency>
+  <groupId>tomcat-session-manager</groupId>
+  <artifactId>redis</artifactId>
+  <version>4.0</version>
+</dependency>
+```
+
 #### Pre-requisite:
 1. jedis.jar
 2. commons-pool2.jar
@@ -33,23 +49,33 @@ more details.. https://github.com/ran-jit/tomcat-cluster-redis-session-manager/w
 
 #### Steps to be done,
 1. Copy the downloaded jars to your tomcat/lib directory.
-	- **tomcat/lib/**
+```
+tomcat/lib/
+```
 	
 2. Add tomcat system property "catalina.base".
-	- **catalina.base="TOMCAT_LOCATION"**
-	     * example: env "catalina.base=/opt/tomcat" bash
+```
+catalina.base="TOMCAT_LOCATION"
+example: env "catalina.base=/opt/tomcat" bash
+```
 
 3. Copy the redis-data-cache.properties file to your tomcat/conf directory and update your Redis server details.
-	- **tomcat/conf/redis-data-cache.properties**
+```
+tomcat/conf/redis-data-cache.properties
+```
 
 4. Add the below two lines in your tomcat/conf/context.xml file.
-	- **&#60;Valve className="tomcat.request.session.redis.SessionHandlerValve" &#47;&#62;**
-	- **&#60;Manager className="tomcat.request.session.redis.SessionManager" &#47;&#62;**
+```
+<Valve className="tomcat.request.session.redis.SessionHandlerValve" />
+<Manager className="tomcat.request.session.redis.SessionManager" />
+```
 
 5. Verify the session expiration time in tomcat/conf/web.xml file.
-	- **&#60;session-config&#62;**
-	- 	&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; **&#60;session-timeout&#62;60&#60;&#47;session-timeout&#62;**
-	- **&#60;&#47;session-config&#62;**
+```
+<session-config>
+  <session-timeout>60</session-timeout>
+</session-config>
+```
 
 ### Note:
   - **All your session attribute values must implement java.io.Serializable.**
@@ -67,7 +93,8 @@ more details.. https://github.com/ran-jit/tomcat-cluster-redis-session-manager/w
         <tr><td>redis.sentinel.enabled</td><td>To enable redis sentinel mode<br/>- default: false<br>- supported values: true/false</td></tr>
         <tr><td>redis.sentinel.master</td><td>Redis sentinel master name<br/>- default: mymaster</td></tr>
         <tr><td>lb.sticky-session.enabled</td><td>To enable redis and standard session mode<br><br>If enabled,<ol><li>Must be enabled sticky session in your load balancer configuration. Else this manager may not return the updated session values</li><li>Session values are stored in local jvm and redis</li><li>If redis is down/not responding, requests uses jvm stored session values to process user requests. Redis comes back the values will be synced</li></ol>- default: false</td></tr>
-	<tr><td>session.persistent.policies</td><td>session persistent policies.<br/><br/>- policies - DEFAULT, SAVE_ON_CHANGE, ALWAYS_SAVE_AFTER_REQUEST <br/><ol><li>SAVE_ON_CHANGE: every time session.setAttribute() or session.removeAttribute() is called the session will be saved.</li><li>ALWAYS_SAVE_AFTER_REQUEST: force saving after every request, regardless of whether or not the manager has detected changes to the session.</li></ol>- default: DEFAULT</td></tr>
+	    <tr><td>session.persistent.policies</td><td>session persistent policies.<br/><br/>- policies - DEFAULT, SAVE_ON_CHANGE, ALWAYS_SAVE_AFTER_REQUEST <br/><ol><li>SAVE_ON_CHANGE: every time session.setAttribute() or session.removeAttribute() is called the session will be saved.</li><li>ALWAYS_SAVE_AFTER_REQUEST: force saving after every request, regardless of whether or not the manager has detected changes to the session.</li></ol>- default: DEFAULT</td></tr>
+	    <tr><td>redis.sso.timeout</td><td>single-sign-on session timeout.<br/>- default: 0 ms (-no expiry)</td></tr>
     </table>
 </body>
 </html>

pom.xml

@@ -2,9 +2,9 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 
     <modelVersion>4.0.0</modelVersion>
-    <groupId>tomcat-cluster-redis-session-manager</groupId>
-    <artifactId>tomcat-cluster-redis-session-manager</artifactId>
-    <version>3.0.4</version>
+    <groupId>tomcat-session-manager</groupId>
+    <artifactId>redis</artifactId>
+    <version>4.0</version>
     <packaging>jar</packaging>
 
     <name>tomcat-cluster-redis-session-manager</name>
@@ -32,12 +32,18 @@
         <target-java.version>${source-java.version}</target-java.version>
 
         <!-- For local development properties begins.. -->
-        <!--<tomcat-catalina.version>apache-tomcat-8.5.32</tomcat-catalina.version>-->
-        <!--<tomcat-servlet-api.version>apache-tomcat-8.5.32</tomcat-servlet-api.version>-->
-        <!--<tomcat-api.version>apache-tomcat-8.5.32</tomcat-api.version>-->
+        <tomcat.version>8.5.32</tomcat.version>
         <!-- For local development properties end.. -->
     </properties>
 
+    <distributionManagement>
+        <repository>
+            <id>repsy</id>
+            <name>tomcat-cluster-redis-session-manager-repo</name>
+            <url>https://repo.repsy.io/mvn/ranmanic/tomcat-session-manager</url>
+        </repository>
+    </distributionManagement>
+
     <dependencies>
         <dependency>
             <groupId>redis.clients</groupId>
@@ -56,21 +62,21 @@
         </dependency>
 
         <!-- For local development dependency begins.. -->
-        <!--<dependency>-->
-            <!--<groupId>apache-tomcat</groupId>-->
-            <!--<artifactId>catalina</artifactId>-->
-            <!--<version>${tomcat-catalina.version}</version>-->
-        <!--</dependency>-->
-        <!--<dependency>-->
-            <!--<groupId>apache-tomcat</groupId>-->
-            <!--<artifactId>servlet-api</artifactId>-->
-            <!--<version>${tomcat-servlet-api.version}</version>-->
-        <!--</dependency>-->
-        <!--<dependency>-->
-            <!--<groupId>apache-tomcat</groupId>-->
-            <!--<artifactId>tomcat-api</artifactId>-->
-            <!--<version>${tomcat-api.version}</version>-->
-        <!--</dependency>-->
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-catalina</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-servlet-api</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-api</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
         <!-- For local development dependency end.. -->
     </dependencies>
 

src/main/java/tomcat/request/session/data/cache/DataCache.java

@@ -45,4 +45,12 @@ public interface DataCache {
      * @return - Returns the number of keys that were removed.
      */
     Long delete(String key);
+
+    /**
+     * Check the key exists in data-cache.
+     *
+     * @param key - key with which the specified value is to be associated.
+     * @return - Returns true, if the key exists.
+     */
+    Boolean exists(String key);
 }

src/main/java/tomcat/request/session/data/cache/impl/StandardDataCache.java

@@ -110,6 +110,12 @@ public class StandardDataCache extends RedisCache {
         return (value == null) ? 0L : 1L;
     }
 
+    /** {@inheritDoc} */
+    @Override
+    public Boolean exists(String key) {
+        return this.sessionData.containsKey(key);
+    }
+
     /** Session data. */
     private static class SessionData implements Serializable {
         private byte[] value;

src/main/java/tomcat/request/session/data/cache/impl/redis/RedisCache.java

@@ -24,31 +24,37 @@ public class RedisCache implements DataCache {
     /** {@inheritDoc} */
     @Override
     public byte[] set(String key, byte[] value) {
-        return dataCache.set(key, value);
+        return this.dataCache.set(key, value);
     }
 
     /** {@inheritDoc} */
     @Override
     public Long setnx(String key, byte[] value) {
-        return dataCache.setnx(key, value);
+        return this.dataCache.setnx(key, value);
     }
 
     /** {@inheritDoc} */
     @Override
     public Long expire(String key, int seconds) {
-        return dataCache.expire(key, seconds);
+        return this.dataCache.expire(key, seconds);
     }
 
     /** {@inheritDoc} */
     @Override
     public byte[] get(String key) {
-        return dataCache.get(key);
+        return this.dataCache.get(key);
     }
 
     /** {@inheritDoc} */
     @Override
     public Long delete(String key) {
-        return dataCache.delete(key);
+        return this.dataCache.delete(key);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public Boolean exists(String key) {
+        return this.dataCache.exists(key);
     }
 
     private void initialize(Config config) {

src/main/java/tomcat/request/session/data/cache/impl/redis/RedisClusterManager.java

@@ -115,4 +115,22 @@ class RedisClusterManager extends RedisManager {
         } while (retry && tries <= NUM_RETRIES);
         return retVal;
     }
+
+    /** {@inheritDoc} */
+    @Override
+    public Boolean exists(String key) {
+        int tries = 0;
+        boolean retry = true;
+        Boolean retVal = null;
+        do {
+            tries++;
+            try {
+                retVal = this.cluster.exists(key);
+                retry = false;
+            } catch (JedisRedirectionException | JedisConnectionException ex) {
+                handleException(tries, ex);
+            }
+        } while (retry && tries <= NUM_RETRIES);
+        return retVal;
+    }
 }

src/main/java/tomcat/request/session/data/cache/impl/redis/RedisManager.java

@@ -113,6 +113,24 @@ abstract class RedisManager implements DataCache {
         return retVal;
     }
 
+    /** {@inheritDoc} */
+    @Override
+    public Boolean exists(String key) {
+        int tries = 0;
+        boolean retry = true;
+        Boolean retVal = null;
+        do {
+            tries++;
+            try (Jedis jedis = this.pool.getResource()) {
+                retVal = jedis.exists(key);
+                retry = false;
+            } catch (JedisConnectionException ex) {
+                handleException(tries, ex);
+            }
+        } while (retry && tries <= NUM_RETRIES);
+        return retVal;
+    }
+
     /**
      * To handle jedis exception.
      *

src/main/java/tomcat/request/session/model/Config.java

@@ -11,6 +11,8 @@ import static tomcat.request.session.annotation.Property.PropertyType.INTEGER;
 /** author: Ranjith Manickam @ 5 Feb' 2020 */
 public class Config implements Serializable {
 
+    private static final long serialVersionUID = 3480402257971437776L;
+
     public static final String APPLICATION_PROPERTIES_FILE = "redis-data-cache.properties";
 
     /** Redis config type. */
@@ -77,6 +79,9 @@ public class Config implements Serializable {
     @Property(name = "session.persistent.policies", defaultValue = "DEFAULT")
     private String sessionPersistentPolicies;
 
+    @Property(name = "redis.sso.timeout", type = INTEGER, defaultValue = "0")
+    private Integer redisSSOTimeout;
+
     public Config() {
     }
 
@@ -98,7 +103,8 @@ public class Config implements Serializable {
                   String redisSentinelMaster,
                   Integer redisSessionExpiryJobInterval,
                   Integer redisSessionDataSyncJobInterval,
-                  String sessionPersistentPolicies) {
+                  String sessionPersistentPolicies,
+                  Integer redisSSOTimeout) {
         this.redisHosts = redisHosts;
         this.redisClusterEnabled = redisClusterEnabled;
         this.redisSentinelEnabled = redisSentinelEnabled;
@@ -118,6 +124,7 @@ public class Config implements Serializable {
         this.redisSessionExpiryJobInterval = redisSessionExpiryJobInterval;
         this.redisSessionDataSyncJobInterval = redisSessionDataSyncJobInterval;
         this.sessionPersistentPolicies = sessionPersistentPolicies;
+        this.redisSSOTimeout = redisSSOTimeout;
     }
 
     /** To get 'redis.hosts' value. */
@@ -215,6 +222,11 @@ public class Config implements Serializable {
         return sessionPersistentPolicies;
     }
 
+    /** To get 'redis.sso.timeout' value */
+    public Integer getRedisSSOTimeout() {
+        return redisSSOTimeout;
+    }
+
     /** {@inheritDoc} */
     @Override
     public String toString() {
@@ -238,6 +250,7 @@ public class Config implements Serializable {
                 ", redisSessionExpiryJobInterval=" + redisSessionExpiryJobInterval +
                 ", redisSessionDataSyncJobInterval=" + redisSessionDataSyncJobInterval +
                 ", sessionPersistentPolicies='" + sessionPersistentPolicies + '\'' +
+                ", redisSSOTimeout='" + redisSSOTimeout + '\'' +
                 '}';
     }
 

src/main/java/tomcat/request/session/model/SingleSignOnEntry.java

@@ -0,0 +1,100 @@
+package tomcat.request.session.model;
+
+import org.apache.catalina.Session;
+import org.apache.catalina.authenticator.SingleSignOnListener;
+import org.apache.catalina.authenticator.SingleSignOnSessionKey;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+import java.security.Principal;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/** author: Ranjith Manickam @ 20 Mar' 2020 */
+public class SingleSignOnEntry implements Serializable {
+
+    private static final long serialVersionUID = 4590485271396917062L;
+
+    private String authType;
+    private String password;
+    private Principal principal;
+    private String username;
+    private boolean canReauthenticate = false;
+    private final ConcurrentMap<SingleSignOnSessionKey, SingleSignOnSessionKey> sessionKeys;
+
+    public SingleSignOnEntry() {
+        this.sessionKeys = new ConcurrentHashMap<>();
+    }
+
+    public SingleSignOnEntry(Principal principal, String authType, String username, String password) {
+        this.sessionKeys = new ConcurrentHashMap<>();
+        this.updateCredentials(principal, authType, username, password);
+    }
+
+    public void addSession(String ssoId, Session session) {
+        SingleSignOnSessionKey key = new SingleSignOnSessionKey(session);
+        SingleSignOnSessionKey currentKey = this.sessionKeys.putIfAbsent(key, key);
+        if (currentKey == null) {
+            session.addSessionListener(new SingleSignOnListener(ssoId));
+        }
+    }
+
+    public void removeSession(Session session) {
+        SingleSignOnSessionKey key = new SingleSignOnSessionKey(session);
+        this.sessionKeys.remove(key);
+    }
+
+    public Set<SingleSignOnSessionKey> findSessions() {
+        return this.sessionKeys.keySet();
+    }
+
+    public String getAuthType() {
+        return this.authType;
+    }
+
+    public boolean getCanReauthenticate() {
+        return this.canReauthenticate;
+    }
+
+    public String getPassword() {
+        return this.password;
+    }
+
+    public Principal getPrincipal() {
+        return this.principal;
+    }
+
+    public String getUsername() {
+        return this.username;
+    }
+
+    public synchronized void updateCredentials(Principal principal, String authType, String username, String password) {
+        this.principal = principal;
+        this.authType = authType;
+        this.username = username;
+        this.password = password;
+        this.canReauthenticate = "BASIC".equals(authType) || "FORM".equals(authType);
+    }
+
+    public void writeObjectData(ObjectOutputStream out) throws IOException {
+        try (ObjectOutputStream outputStream = new ObjectOutputStream(out)) {
+            outputStream.writeObject(this);
+            outputStream.flush();
+        }
+    }
+
+    public void readObjectData(ObjectInputStream in) throws IOException, ClassNotFoundException {
+        try (ObjectInputStream inputStream = new ObjectInputStream(in)) {
+            SingleSignOnEntry entry = (SingleSignOnEntry) inputStream.readObject();
+            this.authType = entry.authType;
+            this.password = entry.password;
+            this.principal = entry.principal;
+            this.username = entry.username;
+            this.canReauthenticate = entry.canReauthenticate;
+            this.sessionKeys.putAll(entry.sessionKeys);
+        }
+    }
+}

src/main/java/tomcat/request/session/redis/SessionHandlerValve.java

@@ -31,7 +31,9 @@ public class SessionHandlerValve extends ValveBase {
             LOGGER.error("Error processing request", ex);
             throw new BackendException();
         } finally {
-            this.manager.afterRequest();
+            if (this.manager != null) {
+                this.manager.afterRequest();
+            }
         }
     }
 }

src/main/java/tomcat/request/session/redis/SessionManager.java

@@ -17,6 +17,7 @@ import tomcat.request.session.model.Config;
 import tomcat.request.session.model.Session;
 import tomcat.request.session.model.SessionContext;
 import tomcat.request.session.model.SessionMetadata;
+import tomcat.request.session.model.SingleSignOnEntry;
 import tomcat.request.session.util.ConfigUtil;
 import tomcat.request.session.util.SerializationUtil;
 
@@ -31,10 +32,11 @@ public class SessionManager extends ManagerBase implements Lifecycle {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(SessionManager.class);
 
+    private Integer ssoTimeout;
     private DataCache dataCache;
     private SerializationUtil serializer;
-    private ThreadLocal<SessionContext> sessionContext = new ThreadLocal<>();
-    private Set<SessionPolicy> sessionPolicy = EnumSet.of(SessionPolicy.DEFAULT);
+    private final ThreadLocal<SessionContext> sessionContext = new ThreadLocal<>();
+    private final Set<SessionPolicy> sessionPolicy = EnumSet.of(SessionPolicy.DEFAULT);
 
     public boolean getSaveOnChange() {
         return this.sessionPolicy.contains(SessionPolicy.SAVE_ON_CHANGE);
@@ -209,6 +211,7 @@ public class SessionManager extends ManagerBase implements Lifecycle {
     private void initialize() {
         try {
             Config config = ConfigUtil.getConfig();
+            this.ssoTimeout = config.getRedisSSOTimeout();
             this.dataCache = new DataCacheFactory(config, getSessionTimeout(null)).getDataCache();
             this.serializer = new SerializationUtil();
 
@@ -335,4 +338,47 @@ public class SessionManager extends ManagerBase implements Lifecycle {
             this.sessionPolicy.add(SessionPolicy.fromName(sessionPolicyName));
         }
     }
+
+    /** To set single-sign-on entry to cache. */
+    void setSingleSignOnEntry(String ssoId, SingleSignOnEntry entry) {
+        if (entry == null) {
+            return;
+        }
+        try {
+            byte[] data = this.serializer.serializeSingleSignOnEntry(entry);
+            this.dataCache.set(ssoId, data);
+            if (this.ssoTimeout > 0) {
+                this.dataCache.expire(ssoId, this.ssoTimeout);
+            }
+        } catch (IOException ex) {
+            LOGGER.error("Error occurred while serializing the single-sign-on entry..", ex);
+        }
+    }
+
+    /** To get single-sign-on entry from cache. */
+    SingleSignOnEntry getSingleSignOnEntry(String ssoId) {
+        byte[] data = this.dataCache.get(ssoId);
+        if (data == null) {
+            return null;
+        }
+
+        SingleSignOnEntry entry = new SingleSignOnEntry();
+        try {
+            this.serializer.deserializeSingleSignOnEntry(data, entry);
+        } catch (IOException | ClassNotFoundException ex) {
+            LOGGER.error("Error occurred while de-serializing the single-sign-on entry..", ex);
+            return null;
+        }
+        return entry;
+    }
+
+    /** To check single-sign-on entry exists from cache. */
+    Boolean singleSignOnEntryExists(String ssoId) {
+        return this.dataCache.exists(ssoId);
+    }
+
+    /** To delete single-sign-on entry from cache. */
+    void deleteSingleSignOnEntry(String ssoId) {
+        this.dataCache.delete(ssoId);
+    }
 }

src/main/java/tomcat/request/session/redis/SingleSignOnValve.java

@@ -0,0 +1,263 @@
+package tomcat.request.session.redis;
+
+import org.apache.catalina.Container;
+import org.apache.catalina.Context;
+import org.apache.catalina.Engine;
+import org.apache.catalina.LifecycleException;
+import org.apache.catalina.Manager;
+import org.apache.catalina.Realm;
+import org.apache.catalina.Session;
+import org.apache.catalina.authenticator.Constants;
+import org.apache.catalina.authenticator.SingleSignOn;
+import org.apache.catalina.authenticator.SingleSignOnSessionKey;
+import org.apache.catalina.connector.Request;
+import org.apache.catalina.connector.Response;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import tomcat.request.session.exception.BackendException;
+import tomcat.request.session.model.SingleSignOnEntry;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.Cookie;
+import java.io.IOException;
+import java.security.Principal;
+import java.util.Set;
+
+/** author: Ranjith Manickam @ 20 Mar' 2020 */
+public class SingleSignOnValve extends SingleSignOn {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(SingleSignOnValve.class);
+
+    private Engine engine;
+    private SessionManager manager;
+
+    /** {@inheritDoc} */
+    @Override
+    protected synchronized void startInternal() throws LifecycleException {
+        Container c;
+        for (c = this.getContainer(); c != null && !(c instanceof Engine); c = c.getParent()) {
+        }
+
+        if (c instanceof Engine) {
+            this.engine = (Engine) c;
+        }
+
+        super.startInternal();
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void invoke(Request request, Response response) throws BackendException {
+        try {
+            this.setSessionManager(request.getContext().getManager());
+
+            request.removeNote("org.apache.catalina.request.SSOID");
+            LOGGER.debug("singleSignOn.debug.invoke, requestURI: {}", request.getRequestURI());
+
+            if (request.getUserPrincipal() == null) {
+                LOGGER.debug("singleSignOn.debug.cookieCheck");
+                Cookie cookie = null;
+                Cookie[] cookies = request.getCookies();
+                if (cookies != null) {
+                    for (Cookie value : cookies) {
+                        if (Constants.SINGLE_SIGN_ON_COOKIE.equals(value.getName())) {
+                            cookie = value;
+                            break;
+                        }
+                    }
+                }
+
+                if (cookie == null) {
+                    LOGGER.debug("singleSignOn.debug.cookieNotFound");
+                } else {
+                    LOGGER.debug("singleSignOn.debug.principalCheck, ssoId: {}", cookie.getValue());
+
+                    SingleSignOnEntry entry = this.manager.getSingleSignOnEntry(cookie.getValue());
+                    if (entry == null) {
+                        LOGGER.debug("singleSignOn.debug.principalNotFound, ssoId: {}", cookie.getValue());
+                        cookie.setValue("REMOVE");
+                        cookie.setMaxAge(0);
+                        cookie.setPath("/");
+                        String domain = this.getCookieDomain();
+                        if (domain != null) {
+                            cookie.setDomain(domain);
+                        }
+
+                        cookie.setSecure(request.isSecure());
+                        if (request.getServletContext().getSessionCookieConfig().isHttpOnly() || request.getContext().getUseHttpOnly()) {
+                            cookie.setHttpOnly(true);
+                        }
+                        response.addCookie(cookie);
+                    } else {
+                        LOGGER.debug("singleSignOn.debug.principalFound, principal: {}, authType: {}", (entry.getPrincipal() != null ? entry.getPrincipal().getName() : ""), entry.getAuthType());
+                        request.setNote("org.apache.catalina.request.SSOID", cookie.getValue());
+                        if (!this.getRequireReauthentication()) {
+                            request.setAuthType(entry.getAuthType());
+                            request.setUserPrincipal(entry.getPrincipal());
+                        }
+                    }
+                }
+            } else {
+                LOGGER.debug("singleSignOn.debug.hasPrincipal, principal: {}", request.getUserPrincipal().getName());
+            }
+            this.getNext().invoke(request, response);
+
+        } catch (IOException | ServletException | RuntimeException ex) {
+            LOGGER.error("Error processing request", ex);
+            throw new BackendException();
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void sessionDestroyed(String ssoId, Session session) {
+        if (this.getState().isAvailable()) {
+            if ((session.getMaxInactiveInterval() <= 0 ||
+                    session.getIdleTimeInternal() < (long) (session.getMaxInactiveInterval() * 1000))
+                    && session.getManager().getContext().getState().isAvailable()) {
+
+                LOGGER.debug("singleSignOn.debug.sessionLogout, session: {}", session);
+                this.removeSession(ssoId, session);
+                if (this.manager.singleSignOnEntryExists(ssoId)) {
+                    this.deregister(ssoId);
+                }
+                return;
+            }
+
+            LOGGER.debug("singleSignOn.debug.sessionTimeout, ssoId: {}, session: {}", ssoId, session);
+            this.removeSession(ssoId, session);
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected boolean associate(String ssoId, Session session) {
+        SingleSignOnEntry entry = this.manager.getSingleSignOnEntry(ssoId);
+        if (entry == null) {
+            LOGGER.debug("singleSignOn.debug.associateFail, ssoId: {}, session: {}", ssoId, session);
+            return false;
+        }
+
+        LOGGER.debug("singleSignOn.debug.associate, ssoId: {}, session: {}", ssoId, session);
+        entry.addSession(ssoId, session);
+        this.manager.setSingleSignOnEntry(ssoId, entry);
+        return true;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected void deregister(String ssoId) {
+        SingleSignOnEntry entry = this.manager.getSingleSignOnEntry(ssoId);
+        this.manager.deleteSingleSignOnEntry(ssoId);
+        if (entry == null) {
+            LOGGER.debug("singleSignOn.debug.deregisterFail, ssoId: {}", ssoId);
+            return;
+        }
+
+        Set<SingleSignOnSessionKey> ssoKeys = entry.findSessions();
+        if (ssoKeys.isEmpty()) {
+            LOGGER.debug("singleSignOn.debug.deregisterNone, ssoId: {}", ssoId);
+        }
+
+        for (SingleSignOnSessionKey ssoKey : ssoKeys) {
+            this.expire(ssoKey);
+            LOGGER.debug("singleSignOn.debug.deregister, ssoKey: {}, ssoId: {}", ssoKey, ssoId);
+        }
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected boolean reauthenticate(String ssoId, Realm realm, Request request) {
+        if (ssoId == null || realm == null) {
+            return false;
+        }
+
+        boolean reAuthenticated = false;
+        SingleSignOnEntry entry = this.manager.getSingleSignOnEntry(ssoId);
+        if (entry != null && entry.getCanReauthenticate()) {
+            String username = entry.getUsername();
+            if (username != null) {
+                Principal reAuthPrincipal = realm.authenticate(username, entry.getPassword());
+                if (reAuthPrincipal != null) {
+                    reAuthenticated = true;
+                    request.setAuthType(entry.getAuthType());
+                    request.setUserPrincipal(reAuthPrincipal);
+                }
+            }
+        }
+        return reAuthenticated;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected void register(String ssoId, Principal principal, String authType, String username, String password) {
+        LOGGER.debug("singleSignOn.debug.register, ssoId: {}, principal: {}, authType: {}", ssoId, (principal != null ? principal.getName() : ""), authType);
+        SingleSignOnEntry entry = new SingleSignOnEntry(principal, authType, username, password);
+        this.manager.setSingleSignOnEntry(ssoId, entry);
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected boolean update(String ssoId, Principal principal, String authType, String username, String password) {
+        SingleSignOnEntry entry = this.manager.getSingleSignOnEntry(ssoId);
+        if (entry == null || !entry.getCanReauthenticate()) {
+            return false;
+        }
+
+        LOGGER.debug("singleSignOn.debug.update, ssoId: {}, authType: {}", ssoId, authType);
+        entry.updateCredentials(principal, authType, username, password);
+        this.manager.setSingleSignOnEntry(ssoId, entry);
+        return true;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    protected void removeSession(String ssoId, Session session) {
+        LOGGER.debug("singleSignOn.debug.removeSession, ssoId: {}, session: {}", ssoId, session);
+        SingleSignOnEntry entry = this.manager.getSingleSignOnEntry(ssoId);
+        if (entry != null) {
+            entry.removeSession(session);
+            if (entry.findSessions().size() == 0) {
+                this.deregister(ssoId);
+            }
+        }
+    }
+
+    /** To set session manager. */
+    void setSessionManager(Manager manager) {
+        if (manager != null) {
+            this.manager = (SessionManager) manager;
+        }
+    }
+
+    /** To expire session. */
+    private void expire(SingleSignOnSessionKey key) {
+        if (this.engine == null) {
+            LOGGER.warn("singleSignOn.sessionExpire.engineNull, key: {}", key);
+        } else {
+            Container host = this.engine.findChild(key.getHostName());
+            if (host == null) {
+                LOGGER.warn("singleSignOn.sessionExpire.hostNotFound, key: {}", key);
+            } else {
+                Context context = (Context) host.findChild(key.getContextName());
+                if (context == null) {
+                    LOGGER.warn("singleSignOn.sessionExpire.contextNotFound, key: {}", key);
+                } else {
+                    Session session;
+                    try {
+                        session = this.manager.findSession(key.getSessionId());
+                    } catch (IOException ex) {
+                        LOGGER.warn("singleSignOn.sessionExpire.managerError, key: {}, exception: {}", key, ex);
+                        return;
+                    }
+
+                    if (session == null) {
+                        LOGGER.warn("singleSignOn.sessionExpire.sessionNotFound, key: {}", key);
+                    } else {
+                        session.expire();
+                    }
+                }
+            }
+        }
+    }
+}

src/main/java/tomcat/request/session/util/SerializationUtil.java

@@ -3,6 +3,7 @@ package tomcat.request.session.util;
 import org.apache.catalina.util.CustomObjectInputStream;
 import tomcat.request.session.model.Session;
 import tomcat.request.session.model.SessionMetadata;
+import tomcat.request.session.model.SingleSignOnEntry;
 
 import java.io.BufferedInputStream;
 import java.io.BufferedOutputStream;
@@ -76,4 +77,25 @@ public class SerializationUtil {
             session.readObjectData(ois);
         }
     }
+
+    /** To serialize single-sign-on entry. */
+    public byte[] serializeSingleSignOnEntry(SingleSignOnEntry entry) throws IOException {
+        byte[] serialized;
+        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(bos))) {
+            entry.writeObjectData(oos);
+            oos.flush();
+            serialized = bos.toByteArray();
+        }
+        return serialized;
+    }
+
+    /** To de-serialize single-sign-on entry. */
+    public void deserializeSingleSignOnEntry(byte[] data, SingleSignOnEntry entry)
+            throws IOException, ClassNotFoundException {
+        try (BufferedInputStream bis = new BufferedInputStream(new ByteArrayInputStream(data));
+             ObjectInputStream ois = new CustomObjectInputStream(bis, this.loader)) {
+            entry.readObjectData(ois);
+        }
+    }
 }

src/main/resources/download_summary.html

@@ -0,0 +1,33 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
+    </head>
+    <body>
+        <div id="download_summary"></div>
+        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
+        <script>
+            $( document ).ready(function() {
+                $.ajax({ 
+                    type: "GET",
+                    dataType: "jsonp",
+                    url: "https://api.github.com/repos/ran-jit/tomcat-cluster-redis-session-manager/releases",
+                    success: function(data){
+                        let content = "<table border='1px' style='width: 80%;margin-left: 10%;margin-right: 10%;line-height: 1.5;'><tr><th style='width: 30%;'>tag</th><th>asset name & download count</th></tr>";
+                        for(let i=0; i< data.data.length; i++) {
+                            const tag = data.data[i];
+                            for(var j=0; j< tag.assets.length; j++) {
+                                const asset = tag.assets[j];
+
+                                content = content + "<tr><td style='width: 10%;'>"+ tag.tag_name + "</td>";    
+                                content = content + "<td>" + asset.name + "<div style='text-align:right;'>" + asset.download_count + "</div></td></tr>";
+                            }
+                        }
+                        content = content + "</table>";
+                        document.getElementById("download_summary").innerHTML=content;
+                    }
+                });
+            });
+        </script>
+    </body>
+</html>

src/main/resources/redis-data-cache.properties

@@ -33,4 +33,7 @@ lb.sticky-session.enabled=false
 # policies - DEFAULT, SAVE_ON_CHANGE, ALWAYS_SAVE_AFTER_REQUEST
 #   1. SAVE_ON_CHANGE: every time session.setAttribute() or session.removeAttribute() is called the session will be saved.
 #   2. ALWAYS_SAVE_AFTER_REQUEST: force saving after every request, regardless of whether or not the manager has detected changes to the session.
-session.persistent.policies=DEFAULT
+session.persistent.policies=DEFAULT
+
+#- single-sign-on session timeout. (default value: 0 ms (-no expiry))
+redis.sso.timeout=0