SSH server and client operations both within a single script using apache sshd. / published by https://github.com/dacr/code-examples-manager #a267b427-a378-445c-b91e-e26ddf889c72/684e62dd8e8f114f54831893fb38ce20169c9bac

ssh-client-server-sync.sc

// summary : SSH server and client operations both within a single script using apache sshd.
// keywords : scala, ssh, client, server, apache-sshd, mina, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : a267b427-a378-445c-b91e-e26ddf889c72
// created-on : 2018-07-02T19:35:49Z
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala "3.4.2"
//> using dep "org.apache.sshd:sshd-core:2.8.0"
//> using dep "org.apache.sshd:sshd-sftp:2.8.0"
//> using dep "org.apache.sshd:sshd-scp:2.8.0"
//> using dep "org.slf4j:slf4j-simple:1.7.32"
// ---------------------

import java.util.concurrent.TimeUnit
import org.apache.sshd.client.SshClient
import org.apache.sshd.common.channel.Channel
import org.apache.sshd.server.SshServer
import org.apache.sshd.server.auth.password.PasswordAuthenticator
import org.apache.sshd.server.keyprovider.SimpleGeneratorHostKeyProvider
import org.apache.sshd.server.session.ServerSession
import java.io.OutputStreamWriter

import org.apache.sshd.client.channel.{ClientChannel, ClientChannelEvent}
import java.io.ByteArrayInputStream
import java.io.ByteArrayOutputStream

import org.apache.sshd.server.shell.ProcessShellFactory


// Everything in a object as soon as we have to deal with futures, promises, asynchronous operations
// 
object Main {
  val sshHost = "localhost"
  val sshPort = 2222
  val testUsername = "test"
  val testPassword = "test"

  def go:Unit = {
    println("Starting operations")

    val sshd = SshServer.setUpDefaultServer
    sshd.setHost(sshHost)
    sshd.setPort(sshPort)
    // first command is the "unparsed one"
    sshd.setShellFactory(new ProcessShellFactory("/bin/cat", "/bin/cat")) // TODO Take care not always installed at this place
    sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider())
    sshd.setPasswordAuthenticator(new PasswordAuthenticator {
      override def authenticate(username: String, password: String, serverSession: ServerSession): Boolean = {
        username==testUsername && password == testPassword
      }
    })
    sshd.start()

    val ssh = SshClient.setUpDefaultClient()
    ssh.start()
    val session = ssh.connect(testUsername, sshHost, sshPort).verify(5, TimeUnit.SECONDS).getSession
    session.addPasswordIdentity(testPassword)
    session.auth.verify(5, TimeUnit.SECONDS)
    val channel:ClientChannel = session.createChannel(Channel.CHANNEL_SHELL)


    val baos = new ByteArrayOutputStream
    val w = new OutputStreamWriter(baos)
    w.write("Hello world")
    //w.flush()
    w.close()

    channel.setIn(new ByteArrayInputStream(baos.toByteArray))
    val out: ByteArrayOutputStream = new ByteArrayOutputStream
    val err: ByteArrayOutputStream = new ByteArrayOutputStream
    channel.setOut(out)
    channel.setErr(err)
    channel.open
    channel.waitFor(java.util.Arrays.asList(ClientChannelEvent.CLOSED), 0)
    
    val result: String = out.toString.trim

    println(s"-->'$result'") // should print 'id' if the current os has an available "/bin/cat" command
    assert(result == "Hello world")
    
    sshd.stop()
  }
}

Main.go