/*
 * Copyright (C) 2016-2021 Lightbend Inc. <https://www.lightbend.com>
 */

package akka.remote.artery
package tcp

import java.security.NoSuchAlgorithmException

import akka.actor.{ ActorIdentity, ActorPath, ActorRef, Identify, RootActorPath }
import akka.actor.setup.ActorSystemSetup
import akka.remote.artery.tcp.ssl.CipherSuiteSupportCheck
import akka.testkit.EventFilter
import akka.testkit.ImplicitSender
import akka.testkit.TestActors
import akka.testkit.TestProbe
import com.typesafe.config.Config
import com.typesafe.config.ConfigFactory
import javax.net.ssl.SSLEngine
import javax.net.ssl.SSLSession
import org.scalatest.matchers.should.Matchers

import scala.concurrent.duration._
import scala.util.{ Failure, Success }

class TlsTcpWithDefaultConfigSpec extends TlsTcpSpec(ConfigFactory.empty())

class TlsTcpWithSHA1PRNGSpec
    extends TlsTcpSpec(ConfigFactory.parseString("""
    akka.remote.artery.ssl.config-ssl-engine {
      random-number-generator = "SHA1PRNG"
      enabled-algorithms = ["TLS_DHE_RSA_WITH_AES_256_GCM_SHA384"]
    }
    """))

class TlsTcpWithDefaultRNGSecureSpec
    extends TlsTcpSpec(ConfigFactory.parseString("""
    akka.remote.artery.ssl.config-ssl-engine {
      random-number-generator = ""
      enabled-algorithms = ["TLS_DHE_RSA_WITH_AES_256_GCM_SHA384"]
    }
    """))

class TlsTcpWithCrappyRSAWithMD5OnlyHereToMakeSureThingsWorkSpec
    extends TlsTcpSpec(ConfigFactory.parseString("""
    akka.remote.artery.ssl.config-ssl-engine {
      random-number-generator = ""
      enabled-algorithms = [""SSL_RSA_WITH_NULL_MD5""]
    }
    """))

class TlsTcpWithRotatingKeysSSLEngineSpec extends TlsTcpSpec(ConfigFactory.parseString(s"""
    akka.remote.artery.ssl {
       ssl-engine-provider = akka.remote.artery.tcp.ssl.RotatingKeysSSLEngineProvider
       rotating-keys-engine {
         key-file = ${TlsTcpSpec.resourcePath("ssl/node.example.com.pem")}
         cert-file = ${TlsTcpSpec.resourcePath("ssl/node.example.com.crt")}
         ca-cert-file = ${TlsTcpSpec.resourcePath("ssl/exampleca.crt")}
       }
    }
    """))

object TlsTcpSpec {
  def resourcePath(name: String): String = getClass.getClassLoader.getResource(name).getPath

  lazy val config: Config = {
    ConfigFactory.parseString(s"""
      akka.remote.artery {
        transport = tls-tcp
        large-message-destinations = [ "/user/large" ]
      }
    """)
  }

}

abstract class TlsTcpSpec(config: Config)
    extends ArteryMultiNodeSpec(config.withFallback(TlsTcpSpec.config))
    with ImplicitSender
    with Matchers {

  val systemB = newRemoteSystem(name = Some("systemB"))
  val addressB = address(systemB)
  val rootB = RootActorPath(addressB)

  def isSupported: Boolean = {
    val checked = system.settings.config.getString("akka.remote.artery.ssl.ssl-engine-provider") match {
      case "akka.remote.artery.tcp.ConfigSSLEngineProvider" =>
        CipherSuiteSupportCheck.isSupported(system, "akka.remote.artery.ssl.config-ssl-engine")
      case "akka.remote.artery.tcp.ssl.RotatingKeysSSLEngineProvider" =>
        CipherSuiteSupportCheck.isSupported(system, "akka.remote.artery.ssl.rotating-keys-engine")
      case other =>
        fail(
          s"Don't know how to determine whether the crypto building blocks in [$other] are available on this platform")
    }
    checked match {
      case Success(()) =>
        true
      case Failure(e @ (_: IllegalArgumentException | _: NoSuchAlgorithmException)) =>
        info(e.toString)
        false
      case Failure(other) =>
        fail("Unexpected failure checking whether the crypto building blocks are available on this platform.", other)
    }
  }

  def identify(path: ActorPath): ActorRef = {
    system.actorSelection(path) ! Identify(path.name)
    expectMsgType[ActorIdentity].ref.get
  }

  def testDelivery(echoRef: ActorRef): Unit = {
    echoRef ! "ping-1"
    expectMsg("ping-1")

    // and some more
    (2 to 10).foreach { n =>
      echoRef ! s"ping-$n"
    }
    receiveN(9) should equal((2 to 10).map(n => s"ping-$n"))
  }

  "Artery with TLS/TCP" must {

    if (isSupported) {

      "deliver messages" in {
        systemB.actorOf(TestActors.echoActorProps, "echo")
        val echoRef = identify(rootB / "user" / "echo")
        testDelivery(echoRef)
      }

      "deliver messages over large messages stream" in {
        systemB.actorOf(TestActors.echoActorProps, "large")
        val echoRef = identify(rootB / "user" / "large")
        testDelivery(echoRef)
      }

    } else {
      "not be run when the cipher is not supported by the platform this test is currently being executed on" in {
        pending
      }
    }
  }

}

class TlsTcpWithHostnameVerificationSpec
    extends ArteryMultiNodeSpec(ConfigFactory.parseString("""
    akka.remote.artery.ssl.config-ssl-engine {
      hostname-verification = on
    }
    akka.remote.use-unsafe-remote-features-outside-cluster = on

    akka.loggers = ["akka.testkit.TestEventListener"]
    """).withFallback(TlsTcpSpec.config))
    with ImplicitSender {

  "Artery with TLS/TCP and hostname-verification=on" must {
    "fail when the name in the server certificate does not match" in {
      // this test only makes sense with tls-tcp transport
      if (!arteryTcpTlsEnabled())
        pending

      val systemB = newRemoteSystem(
        // The subjectAltName is 'localhost', so connecting to '127.0.0.1' should not
        // work when using hostname verification:
        extraConfig = Some("""akka.remote.artery.canonical.hostname = "127.0.0.1""""),
        name = Some("systemB"))

      val addressB = address(systemB)
      val rootB = RootActorPath(addressB)

      systemB.actorOf(TestActors.echoActorProps, "echo")
      // The detailed warning message is either 'General SSLEngine problem'
      // or 'No subject alternative names matching IP address 127.0.0.1 found'
      // depending on JRE version.
      EventFilter
        .warning(
          pattern =
            "outbound connection to \\[akka://systemB@127.0.0.1:.*" +
            "Upstream failed, cause: SSLHandshakeException: .*",
          occurrences = 3)
        .intercept {
          system.actorSelection(rootB / "user" / "echo") ! Identify("echo")
        }
      expectNoMessage(2.seconds)
      systemB.terminate()
    }
    "succeed when the name in the server certificate matches" in {
      if (!arteryTcpTlsEnabled())
        pending

      val systemB = newRemoteSystem(
        extraConfig = Some("""
          // The subjectAltName is 'localhost', so this is how we want to be known:
          akka.remote.artery.canonical.hostname = "localhost"

          // Though we will still bind to 127.0.0.1 (make sure it's not ipv6)
          akka.remote.artery.bind.hostname = "127.0.0.1"
        """),
        name = Some("systemB"))

      val addressB = address(systemB)
      val rootB = RootActorPath(addressB)

      systemB.actorOf(TestActors.echoActorProps, "echo")
      system.actorSelection(rootB / "user" / "echo") ! Identify("echo")
      val id = expectMsgType[ActorIdentity]

      id.ref.get ! "42"
      expectMsg("42")

      systemB.terminate()
    }
  }
}

class TlsTcpWithActorSystemSetupSpec extends ArteryMultiNodeSpec(TlsTcpSpec.config) with ImplicitSender {

  val sslProviderServerProbe = TestProbe()
  val sslProviderClientProbe = TestProbe()

  val sslProviderSetup = SSLEngineProviderSetup(sys =>
    new SSLEngineProvider {
      val delegate = new ConfigSSLEngineProvider(sys)
      override def createServerSSLEngine(hostname: String, port: Int): SSLEngine = {
        sslProviderServerProbe.ref ! "createServerSSLEngine"
        delegate.createServerSSLEngine(hostname, port)
      }

      override def createClientSSLEngine(hostname: String, port: Int): SSLEngine = {
        sslProviderClientProbe.ref ! "createClientSSLEngine"
        delegate.createClientSSLEngine(hostname, port)
      }
      override def verifyClientSession(hostname: String, session: SSLSession): Option[Throwable] =
        delegate.verifyClientSession(hostname, session)
      override def verifyServerSession(hostname: String, session: SSLSession): Option[Throwable] =
        delegate.verifyServerSession(hostname, session)
    })

  val systemB = newRemoteSystem(name = Some("systemB"), setup = Some(ActorSystemSetup(sslProviderSetup)))
  val addressB = address(systemB)
  val rootB = RootActorPath(addressB)

  "Artery with TLS/TCP with SSLEngineProvider defined via Setup" must {
    "use the right SSLEngineProvider" in {
      if (!arteryTcpTlsEnabled())
        pending

      systemB.actorOf(TestActors.echoActorProps, "echo")
      val path = rootB / "user" / "echo"
      system.actorSelection(path) ! Identify(path.name)
      val echoRef = expectMsgType[ActorIdentity].ref.get
      echoRef ! "ping-1"
      expectMsg("ping-1")

      sslProviderServerProbe.expectMsg("createServerSSLEngine")
      sslProviderClientProbe.expectMsg("createClientSSLEngine")
    }
  }
}
