communication/src/main/scala/org/apache/toree/communication/security/SignatureManagerActor.scala

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License
 */

package org.apache.toree.communication.security

import org.apache.pekko.actor.{Props, ActorRef, Actor}
import org.apache.pekko.util.Timeout
import org.apache.toree.communication.utils.OrderedSupport
import org.apache.toree.kernel.protocol.v5.KernelMessage
import org.apache.toree.utils.LogLike

import scala.concurrent.duration._
import org.apache.pekko.pattern.ask
import org.apache.pekko.pattern.pipe

class SignatureManagerActor(
  key: String, scheme: String
) extends Actor with LogLike with OrderedSupport {
  private val hmac = Hmac(key, HmacAlgorithm(scheme))

  def this(key: String) = this(key, HmacAlgorithm.SHA256.toString)

  // NOTE: Required to provide the execution context for futures with akka
  import context._

  // NOTE: Required for ask (?) to function... maybe can define elsewhere?
  implicit val timeout = Timeout(5.seconds)

  //
  // List of child actors that the signature manager contains
  //
  private var signatureChecker: ActorRef = _
  private var signatureProducer: ActorRef = _

  /**
   * Initializes all child actors performing tasks for the interpreter.
   */
  override def preStart() = {
    signatureChecker = context.actorOf(
      Props(classOf[SignatureCheckerActor], hmac),
      name = SignatureManagerChildActorType.SignatureChecker.toString
    )
    signatureProducer = context.actorOf(
      Props(classOf[SignatureProducerActor], hmac),
      name = SignatureManagerChildActorType.SignatureProducer.toString
    )
  }

  override def receive: Receive = {
    // Check blob strings for matching digest
    case (signature: String, blob: Seq[_]) =>
      startProcessing()
      val destActor = sender()
      val sigFuture = signatureChecker ? ((signature, blob))

      sigFuture foreach { case isValid =>
          destActor ! isValid
          finishedProcessing()
      }

    case message: KernelMessage =>
      startProcessing()
      val destActor = sender()

      // TODO: Proper error handling for possible exception from mapTo
      val sigFuture = (signatureProducer ? message).mapTo[String].map(
        result => message.copy(signature = result)
      )

      sigFuture foreach { case kernelMessage =>
        destActor ! kernelMessage
        finishedProcessing()
      }
  }

  /**
   * Defines the types that will be stashed by [[waiting]]
   * while the Actor is in processing state.
   * @return
   */
  override def orderedTypes(): Seq[Class[_]] = Seq(
    classOf[(String, Seq[_])],
    classOf[KernelMessage]
  )
}