V1.0.2 Look up a command reply in a properties file

conf/replies.properties

@@ -0,0 +1,7 @@
+hello=hello
+5BAABD7C4581F90088133C0E945302C2=\t0\t0\t0 -
+uname=Linux
+9DD46246144D353C914D7572AEDF8EA6=Linux mail.vidconnect.cyou 4.15.0-70-generic #79-Ubuntu SMP Tue Nov 12 10:36:10 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux
+whoami=appadmin
+4DE8A3B5E72E54D9D2A70BD43CB5EA9E=Model:\t\t0
+99EFF9F4022855955653078ECB2B4CE4=1.9G

conf/springboot.yml

@@ -2,3 +2,5 @@ ssh-server:
   port: 1022
   private-key:
     location: "conf/private.key"
+  automatic-replies:
+    location: "conf/replies.properties"

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.example.sshd</groupId>
 	<artifactId>echo-sshd-server</artifactId>
-	<version>1.0.1</version>
+	<version>1.0.2</version>
 	<name>ECHO SSH SERVER</name>
 	<description>Learning Apache Mina SSHD library</description>
 	<parent>
@@ -33,6 +33,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-log4j2</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>commons-codec</groupId>
+			<artifactId>commons-codec</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.apache.mina</groupId>
 			<artifactId>mina-core</artifactId>

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

@@ -0,0 +1,110 @@
+package com.example.sshd.config;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Properties;
+
+import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.sshd.server.Command;
+import org.apache.sshd.server.Environment;
+import org.apache.sshd.server.ExitCallback;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.context.annotation.Scope;
+import org.springframework.stereotype.Component;
+
+@Component
+@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
+public class OnetimeCommand implements Command {
+
+	private static final Logger logger = LoggerFactory.getLogger(OnetimeCommand.class);
+
+	@Autowired
+	Properties repliesProperties;
+
+	private InputStream in;
+	private OutputStream out;
+	private OutputStream err;
+	private ExitCallback callback;
+	private Environment environment;
+	private String command;
+
+	public OnetimeCommand(String cmd) {
+		command = cmd;
+	}
+
+	public InputStream getIn() {
+		return in;
+	}
+
+	public OutputStream getOut() {
+		return out;
+	}
+
+	public OutputStream getErr() {
+		return err;
+	}
+
+	public Environment getEnvironment() {
+		return environment;
+	}
+
+	@Override
+	public void setInputStream(InputStream in) {
+		this.in = in;
+	}
+
+	@Override
+	public void setOutputStream(OutputStream out) {
+		this.out = out;
+	}
+
+	@Override
+	public void setErrorStream(OutputStream err) {
+		this.err = err;
+	}
+
+	@Override
+	public void setExitCallback(ExitCallback callback) {
+		this.callback = callback;
+	}
+
+	@Override
+	public void start(Environment env) throws IOException {
+		environment = env;
+		String cmdHash = DigestUtils.md5Hex(command).toUpperCase();
+		logger.info("command = {}, cmdHash = {}", command, cmdHash);
+
+		if (StringUtils.equals(command, "exit")) {
+			logger.info("Exiting command detected: {}", command);
+			out.write(("\r\nExiting...\r\n").getBytes());
+		} else if (repliesProperties.containsKey(command)) {
+			logger.info("Known command detected: {}", command);
+			String reply = repliesProperties.getProperty(command).replace("\\r", "\r").replace("\\n", "\n")
+					.replace("\\t", "\t");
+			out.write(("\r\n" + reply + "\r\n").getBytes());
+		} else if (repliesProperties.containsKey(cmdHash)) {
+			logger.info("Known command-hash detected: {}", cmdHash);
+			String reply = repliesProperties.getProperty(cmdHash).replace("\\r", "\r").replace("\\n", "\n")
+					.replace("\\t", "\t");
+			out.write(("\r\n" + reply + "\r\n").getBytes());
+		} else {
+			logger.info("Command not found: {}", command);
+			out.write(("\r\nCommand '" + command + "' not found. Try 'exit'.\r\n").getBytes());
+		}
+		out.flush();
+		callback.onExit(0);
+	}
+
+	@Override
+	public void destroy() {
+	}
+
+	public ExitCallback getCallback() {
+		return callback;
+	}
+}

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

@@ -1,8 +1,10 @@
 package com.example.sshd.config;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.security.NoSuchAlgorithmException;
+import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
 import org.apache.sshd.SshServer;
@@ -11,9 +13,13 @@ import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider;
 import org.apache.sshd.server.session.ServerSession;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Scope;
 
 @Configuration
 public class SshConfig {
@@ -29,6 +35,12 @@ public class SshConfig {
 	@Value("${ssh-server.root.username:root}")
 	private String rootUsername;
 
+	@Value("${ssh-server.automatic-replies.location}")
+	private String repliesProperties;
+
+	@Autowired
+	ApplicationContext applicationContext;
+
 	@Bean
 	public SshServer sshd() throws IOException, NoSuchAlgorithmException {
 		SshServer sshd = SshServer.setUpDefaultServer();
@@ -43,7 +55,18 @@ public class SshConfig {
 			}
 		});
 		sshd.setShellFactory(new EchoShellFactory());
+		sshd.setCommandFactory(command -> applicationContext.getBean(OnetimeCommand.class, command));
 		sshd.start();
 		return sshd;
 	}
+
+	@Bean
+	@Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)
+	public Properties repliesProperties() throws IOException {
+		Properties prop = new Properties();
+		File configFile = new File(repliesProperties);
+		FileInputStream stream = new FileInputStream(configFile);
+		prop.load(stream);
+		return prop;
+	}
 }