Initial commit

.gitignore

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+/target/
+/.classpath
+/.project
+/.settings

conf/.gitignore

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+/private.key

conf/log4j2.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<Configuration status="DEBUG">
+	<Appenders>
+		<Console name="LogToConsole" target="SYSTEM_OUT">
+			<PatternLayout
+				pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} %p [%t] %c : %m%n" />
+		</Console>
+		<RollingFile name="LogToFile"
+			filePattern="logs/server.%d{yyyy-MM-dd}.log"
+			immediateFlush="true">
+			<PatternLayout
+				pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} %p [%t] %c : %m%n" />
+			<Policies>
+				<TimeBasedTriggeringPolicy interval="1" modulate="true" />
+			</Policies>
+		</RollingFile>
+	</Appenders>
+	<Loggers>
+		<Root level="info">
+			<AppenderRef ref="LogToConsole" />
+		</Root>
+	</Loggers>
+</Configuration>

conf/springboot.yml

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+ssh-server:
+  port: 1022
+  private-key:
+    location: "conf/private.key"

pom.xml

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+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>com.example.sshd</groupId>
+	<artifactId>echo-sshd-server</artifactId>
+	<version>1.0.0</version>
+	<name>ECHO SSH SERVER</name>
+	<description>Learning Apache Mina SSHD library</description>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>3.3.2</version>
+	</parent>
+	<properties>
+		<mina.version>2.0.25</mina.version>
+		<sshd.version>0.14.0</sshd.version>
+		<bouncycastle.version>1.78.1</bouncycastle.version>
+		<commons-io.version>2.13.0</commons-io.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter</artifactId>
+			<exclusions>
+				<exclusion>
+					<groupId>org.springframework.boot</groupId>
+					<artifactId>spring-boot-starter-logging</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-log4j2</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.mina</groupId>
+			<artifactId>mina-core</artifactId>
+			<version>${mina.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.sshd</groupId>
+			<artifactId>sshd-core</artifactId>
+			<version>${sshd.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.bouncycastle</groupId>
+			<artifactId>bcprov-jdk18on</artifactId>
+			<version>${bouncycastle.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.bouncycastle</groupId>
+			<artifactId>bcpkix-jdk18on</artifactId>
+			<version>${bouncycastle.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>commons-io</groupId>
+			<artifactId>commons-io</artifactId>
+			<version>${commons-io.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.commons</groupId>
+			<artifactId>commons-lang3</artifactId>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-compiler-plugin</artifactId>
+				<configuration>
+					<source>17</source>
+					<target>17</target>
+				</configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<configuration>
+					<mainClass>com.example.sshd.Boot</mainClass>
+				</configuration>
+				<executions>
+					<execution>
+						<id>build-info</id>
+						<goals>
+							<goal>build-info</goal>
+						</goals>
+					</execution>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

src/main/java/com/example/sshd/Boot.java

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+package com.example.sshd;
+
+import org.apache.sshd.SshServer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Boot {
+
+	private static final Logger logger = LoggerFactory.getLogger(Boot.class);
+
+	@Autowired
+	protected SshServer sshd;
+
+	public static void main(String[] args) throws Exception {
+		String configDirectory = "conf";
+		if (args.length > 0) {
+			configDirectory = args[0];
+		}
+		logger.info("config directory: {}", configDirectory);
+
+		if (new java.io.File(configDirectory).exists() && new java.io.File(configDirectory).isDirectory()) {
+			System.setProperty("spring.config.location", configDirectory + "/springboot.yml");
+			System.setProperty("logging.config", configDirectory + "/log4j2.xml");
+		}
+		SpringApplication.run(Boot.class, args);
+	} 
+}

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

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+package com.example.sshd.config;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.util.UUID;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.sshd.common.Factory;
+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;
+
+public class EchoShellFactory implements Factory<Command> {
+
+	private static final Logger logger = LoggerFactory.getLogger(EchoShellFactory.class);
+
+	@Override
+	public Command create() {
+		return new EchoShell();
+	}
+
+	public static class EchoShell implements Command, Runnable {
+
+		private InputStream in;
+		private OutputStream out;
+		private OutputStream err;
+		private ExitCallback callback;
+		private Environment environment;
+		private Thread thread;
+
+		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;
+			thread = new Thread(this, UUID.randomUUID().toString());
+			thread.start();
+		}
+
+		@Override
+		public void destroy() {
+			thread.interrupt();
+		}
+
+		@Override
+		public void run() {
+			try {
+				out.write("$ ".getBytes());
+				out.flush();
+
+				BufferedReader r = new BufferedReader(new InputStreamReader(in));
+				String command = "";
+
+				while (!Thread.currentThread().isInterrupted()) {
+					int s = r.read();
+					if (s == 13 || s == 10) {
+
+						if (StringUtils.isBlank(command)) {
+							logger.info("Blank command detected: {}", command);
+							out.write(("\r\n$ ").getBytes());
+						} else if (StringUtils.equals(command, "exit")) {
+							logger.info("Exiting command detected: {}", command);
+							return;
+						} else {
+							logger.info("Command not found: {}", command);
+							out.write(("\r\nCommand '" + command + "' not found. Try 'exit'.\r\n$ ").getBytes());
+						}
+						command = "";
+					} else {
+						out.write(s);
+						command += (char) s;
+					}
+					out.flush();
+				}
+			} catch (Exception e) {
+				logger.error("run error!", e);
+			} finally {
+				callback.onExit(0);
+			}
+		}
+	}
+}

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

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+package com.example.sshd.config;
+
+import java.io.File;
+import java.io.IOException;
+import java.security.NoSuchAlgorithmException;
+
+import org.apache.commons.lang3.StringUtils;
+import org.apache.sshd.SshServer;
+import org.apache.sshd.server.PasswordAuthenticator;
+import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider;
+import org.apache.sshd.server.session.ServerSession;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class SshConfig {
+
+	@Value("${ssh-server.port}")
+	private int port;
+
+	@Value("${ssh-server.private-key.location}")
+	private String pkLocation;
+
+	@Value("${ssh-server.root.username:root}")
+	private String rootUsername;
+
+	@Bean
+	public SshServer sshd() throws IOException, NoSuchAlgorithmException {
+		SshServer sshd = SshServer.setUpDefaultServer();
+		sshd.setPort(port);
+		sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider(new File(pkLocation).getPath(), "RSA", 2048));
+
+		sshd.setPasswordAuthenticator(new PasswordAuthenticator() {
+			@Override
+			public boolean authenticate(final String username, final String password, final ServerSession session) {
+				return StringUtils.equals(username, rootUsername);
+			}
+		});
+		sshd.setShellFactory(new EchoShellFactory());
+		sshd.start();
+		return sshd;
+	}
+}