V1.1.1 Only one session is allowed. New session will override the old.

conf/log4j2.xml

@@ -26,10 +26,10 @@
 	</Appenders>
 	<Loggers>
 		<Logger name="not_found" level="info" additivity="false">
-			<AppenderRef ref="LogToNotFound" />
+			<AppenderRef ref="LogToConsole" />
 		</Logger>
 		<Root level="info">
-			<AppenderRef ref="LogToFile" />
+			<AppenderRef ref="LogToConsole" />
 		</Root>
 	</Loggers>
 </Configuration>

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.example.sshd</groupId>
 	<artifactId>echo-sshd-server</artifactId>
-	<version>1.1.0</version>
+	<version>1.1.1</version>
 	<name>ECHO SSH SERVER</name>
 	<description>Learning Apache Mina SSHD library</description>
 	<parent>

src/main/java/com/example/sshd/config/AppConfig.java

@@ -0,0 +1,21 @@
+package com.example.sshd.config;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.sshd.common.Session;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Scope;
+
+@Configuration
+public class AppConfig {
+
+	@Bean
+	@Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)
+	public Map<String, Session> remoteSessionMapping() {
+		return Collections.synchronizedMap(new HashMap<>());
+	}
+}

src/main/java/com/example/sshd/config/SshConfig.java

@@ -4,9 +4,9 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
 import java.util.Properties;
 
-import org.apache.commons.lang3.StringUtils;
 import org.apache.sshd.SshServer;
 import org.apache.sshd.server.PasswordAuthenticator;
 import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider;
@@ -21,6 +21,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Scope;
 
+import com.example.sshd.core.EchoSessionListener;
 import com.example.sshd.core.EchoShellFactory;
 import com.example.sshd.core.OnetimeCommand;
 
@@ -35,8 +36,8 @@ public class SshConfig {
 	@Value("${ssh-server.private-key.location}")
 	private String pkLocation;
 
-	@Value("${ssh-server.root.username:root}")
-	private String rootUsername;
+	@Value("${ssh-server.login.usernames:root}")
+	private String[] usernames;
 
 	@Value("${ssh-server.hash-replies.location}")
 	private String hashReplies;
@@ -57,12 +58,14 @@ public class SshConfig {
 			@Override
 			public boolean authenticate(final String username, final String password, final ServerSession session) {
 				logger.info("Login Attempt: username = {}, password = {}", username, password);
-				return StringUtils.equals(username, rootUsername);
+				return Arrays.asList(usernames).contains(username);
 			}
 		});
 		sshd.setShellFactory(applicationContext.getBean(EchoShellFactory.class));
 		sshd.setCommandFactory(command -> applicationContext.getBean(OnetimeCommand.class, command));
+		
 		sshd.start();
+		sshd.getSessionFactory().addListener(applicationContext.getBean(EchoSessionListener.class));
 		return sshd;
 	}
 

src/main/java/com/example/sshd/core/EchoSessionListener.java

@@ -0,0 +1,46 @@
+package com.example.sshd.core;
+
+import java.net.InetSocketAddress;
+import java.util.Map;
+
+import org.apache.sshd.common.Session;
+import org.apache.sshd.common.SessionListener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+public class EchoSessionListener implements SessionListener {
+
+	private static final Logger logger = LoggerFactory.getLogger(EchoSessionListener.class);
+
+	@Autowired
+	Map<String, Session> remoteSessionMapping;
+
+	@Override
+	public void sessionCreated(Session session) {
+		logger.info("sessionCreated: {}", session);
+		if (session.getIoSession().getRemoteAddress() instanceof InetSocketAddress) {
+			InetSocketAddress remoteAddress = (InetSocketAddress) session.getIoSession().getRemoteAddress();
+			String remoteIpAddress = remoteAddress.getAddress().getHostAddress();
+			if (remoteSessionMapping.containsKey(remoteIpAddress)) {
+				logger.info("kill old session: {} -> {}", remoteIpAddress, remoteSessionMapping.get(remoteIpAddress));
+				remoteSessionMapping.get(remoteIpAddress).close(false);
+			}
+			logger.info("new session: {} -> {}", remoteIpAddress, session);
+			remoteSessionMapping.put(remoteIpAddress, session);
+		}
+	}
+
+	@Override
+	public void sessionEvent(Session session, Event event) {
+		logger.info("sessionEvent: {}, event: {}", session, event);
+	}
+
+	@Override
+	public void sessionClosed(Session session) {
+		logger.info("sessionCreated: {}", session);
+	}
+
+}