[SPARK-19520][STREAMING] Do not encrypt data written to the WAL.

Spark's I/O encryption uses an ephemeral key for each driver instance.
So driver B cannot decrypt data written by driver A since it doesn't
have the correct key.

The write ahead log is used for recovery, thus needs to be readable by
a different driver. So it cannot be encrypted by Spark's I/O encryption
code.

The BlockManager APIs used by the WAL code to write the data automatically
encrypt data, so changes are needed so that callers can to opt out of
encryption.

Aside from that, the "putBytes" API in the BlockManager does not do
encryption, so a separate situation arised where the WAL would write
unencrypted data to the BM and, when those blocks were read, decryption
would fail. So the WAL code needs to ask the BM to encrypt that data
when encryption is enabled; this code is not optimal since it results
in a (temporary) second copy of the data block in memory, but should be
OK for now until a more performant solution is added. The non-encryption
case should not be affected.

Tested with new unit tests, and by running streaming apps that do
recovery using the WAL data with I/O encryption turned on.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #16862 from vanzin/SPARK-19520.

8 files changed, 120 insertions, 30 deletions

diff --git a/core/src/main/scala/org/apache/spark/SecurityManager.scala b/core/src/main/scala/org/apache/spark/SecurityManager.scala
index cde768281f..2480e56b72 100644
--- a/core/src/main/scala/org/apache/spark/SecurityManager.scala
+++ b/core/src/main/scala/org/apache/spark/SecurityManager.scala
@@ -184,7 +184,7 @@ import org.apache.spark.util.Utils
 
 private[spark] class SecurityManager(
     sparkConf: SparkConf,
-    ioEncryptionKey: Option[Array[Byte]] = None)
+    val ioEncryptionKey: Option[Array[Byte]] = None)
   extends Logging with SecretKeyHolder {
 
   import SecurityManager._
diff --git a/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala b/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala
index 748f0a30ad..96b288b9cf 100644
--- a/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala
+++ b/core/src/main/scala/org/apache/spark/serializer/SerializerManager.scala
@@ -171,20 +171,26 @@ private[spark] class SerializerManager(
   }
 
   /** Serializes into a chunked byte buffer. */
-  def dataSerialize[T: ClassTag](blockId: BlockId, values: Iterator[T]): ChunkedByteBuffer = {
-    dataSerializeWithExplicitClassTag(blockId, values, implicitly[ClassTag[T]])
+  def dataSerialize[T: ClassTag](
+      blockId: BlockId,
+      values: Iterator[T],
+      allowEncryption: Boolean = true): ChunkedByteBuffer = {
+    dataSerializeWithExplicitClassTag(blockId, values, implicitly[ClassTag[T]],
+      allowEncryption = allowEncryption)
   }
 
   /** Serializes into a chunked byte buffer. */
   def dataSerializeWithExplicitClassTag(
       blockId: BlockId,
       values: Iterator[_],
-      classTag: ClassTag[_]): ChunkedByteBuffer = {
+      classTag: ClassTag[_],
+      allowEncryption: Boolean = true): ChunkedByteBuffer = {
     val bbos = new ChunkedByteBufferOutputStream(1024 * 1024 * 4, ByteBuffer.allocate)
     val byteStream = new BufferedOutputStream(bbos)
     val autoPick = !blockId.isInstanceOf[StreamBlockId]
     val ser = getSerializer(classTag, autoPick).newInstance()
-    ser.serializeStream(wrapStream(blockId, byteStream)).writeAll(values).close()
+    val encrypted = if (allowEncryption) wrapForEncryption(byteStream) else byteStream
+    ser.serializeStream(wrapForCompression(blockId, encrypted)).writeAll(values).close()
     bbos.toChunkedByteBuffer
   }
 
@@ -194,13 +200,15 @@ private[spark] class SerializerManager(
    */
   def dataDeserializeStream[T](
       blockId: BlockId,
-      inputStream: InputStream)
+      inputStream: InputStream,
+      maybeEncrypted: Boolean = true)
       (classTag: ClassTag[T]): Iterator[T] = {
     val stream = new BufferedInputStream(inputStream)
     val autoPick = !blockId.isInstanceOf[StreamBlockId]
+    val decrypted = if (maybeEncrypted) wrapForEncryption(inputStream) else inputStream
     getSerializer(classTag, autoPick)
       .newInstance()
-      .deserializeStream(wrapStream(blockId, stream))
+      .deserializeStream(wrapForCompression(blockId, decrypted))
       .asIterator.asInstanceOf[Iterator[T]]
   }
 }
diff --git a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
index c40186756f..6946a98cdd 100644
--- a/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
+++ b/core/src/main/scala/org/apache/spark/storage/BlockManager.scala
@@ -28,6 +28,8 @@ import scala.reflect.ClassTag
 import scala.util.Random
 import scala.util.control.NonFatal
 
+import com.google.common.io.ByteStreams
+
 import org.apache.spark._
 import org.apache.spark.executor.{DataReadMethod, ShuffleWriteMetrics}
 import org.apache.spark.internal.Logging
@@ -38,6 +40,7 @@ import org.apache.spark.network.netty.SparkTransportConf
 import org.apache.spark.network.shuffle.ExternalShuffleClient
 import org.apache.spark.network.shuffle.protocol.ExecutorShuffleInfo
 import org.apache.spark.rpc.RpcEnv
+import org.apache.spark.security.CryptoStreamUtils
 import org.apache.spark.serializer.{SerializerInstance, SerializerManager}
 import org.apache.spark.shuffle.ShuffleManager
 import org.apache.spark.storage.memory._
@@ -752,15 +755,43 @@ private[spark] class BlockManager(
   /**
    * Put a new block of serialized bytes to the block manager.
    *
+   * @param encrypt If true, asks the block manager to encrypt the data block before storing,
+   *                when I/O encryption is enabled. This is required for blocks that have been
+   *                read from unencrypted sources, since all the BlockManager read APIs
+   *                automatically do decryption.
    * @return true if the block was stored or false if an error occurred.
    */
   def putBytes[T: ClassTag](
       blockId: BlockId,
       bytes: ChunkedByteBuffer,
       level: StorageLevel,
-      tellMaster: Boolean = true): Boolean = {
+      tellMaster: Boolean = true,
+      encrypt: Boolean = false): Boolean = {
     require(bytes != null, "Bytes is null")
-    doPutBytes(blockId, bytes, level, implicitly[ClassTag[T]], tellMaster)
+
+    val bytesToStore =
+      if (encrypt && securityManager.ioEncryptionKey.isDefined) {
+        try {
+          val data = bytes.toByteBuffer
+          val in = new ByteBufferInputStream(data, true)
+          val byteBufOut = new ByteBufferOutputStream(data.remaining())
+          val out = CryptoStreamUtils.createCryptoOutputStream(byteBufOut, conf,
+            securityManager.ioEncryptionKey.get)
+          try {
+            ByteStreams.copy(in, out)
+          } finally {
+            in.close()
+            out.close()
+          }
+          new ChunkedByteBuffer(byteBufOut.toByteBuffer)
+        } finally {
+          bytes.dispose()
+        }
+      } else {
+        bytes
+      }
+
+    doPutBytes(blockId, bytesToStore, level, implicitly[ClassTag[T]], tellMaster)
   }
 
   /**
diff --git a/docs/streaming-programming-guide.md b/docs/streaming-programming-guide.md
index 38b4f78177..a878971608 100644
--- a/docs/streaming-programming-guide.md
+++ b/docs/streaming-programming-guide.md
@@ -2017,6 +2017,9 @@ To run a Spark Streaming applications, you need to have the following.
   `spark.streaming.driver.writeAheadLog.closeFileAfterWrite` and
   `spark.streaming.receiver.writeAheadLog.closeFileAfterWrite`. See
   [Spark Streaming Configuration](configuration.html#spark-streaming) for more details.
+  Note that Spark will not encrypt data written to the write ahead log when I/O encryption is
+  enabled. If encryption of the write ahead log data is desired, it should be stored in a file
+  system that supports encryption natively.
 
 - *Setting the max receiving rate* - If the cluster resources is not large enough for the streaming
   application to process data as fast as it is being received, the receivers can be rate limited
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDD.scala b/streaming/src/main/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDD.scala
index 0b2ec29813..d0864fd367 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDD.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDD.scala
@@ -27,7 +27,7 @@ import org.apache.spark._
 import org.apache.spark.rdd.BlockRDD
 import org.apache.spark.storage.{BlockId, StorageLevel}
 import org.apache.spark.streaming.util._
-import org.apache.spark.util.SerializableConfiguration
+import org.apache.spark.util._
 import org.apache.spark.util.io.ChunkedByteBuffer
 
 /**
@@ -158,13 +158,16 @@ class WriteAheadLogBackedBlockRDD[T: ClassTag](
       logInfo(s"Read partition data of $this from write ahead log, record handle " +
         partition.walRecordHandle)
       if (storeInBlockManager) {
-        blockManager.putBytes(blockId, new ChunkedByteBuffer(dataRead.duplicate()), storageLevel)
+        blockManager.putBytes(blockId, new ChunkedByteBuffer(dataRead.duplicate()), storageLevel,
+          encrypt = true)
         logDebug(s"Stored partition data of $this into block manager with level $storageLevel")
         dataRead.rewind()
       }
       serializerManager
         .dataDeserializeStream(
-          blockId, new ChunkedByteBuffer(dataRead).toInputStream())(elementClassTag)
+          blockId,
+          new ChunkedByteBuffer(dataRead).toInputStream(),
+          maybeEncrypted = false)(elementClassTag)
         .asInstanceOf[Iterator[T]]
     }
 
diff --git a/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceivedBlockHandler.scala b/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceivedBlockHandler.scala
index 80c07958b4..2b488038f0 100644
--- a/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceivedBlockHandler.scala
+++ b/streaming/src/main/scala/org/apache/spark/streaming/receiver/ReceivedBlockHandler.scala
@@ -87,7 +87,8 @@ private[streaming] class BlockManagerBasedBlockHandler(
         putResult
       case ByteBufferBlock(byteBuffer) =>
         blockManager.putBytes(
-          blockId, new ChunkedByteBuffer(byteBuffer.duplicate()), storageLevel, tellMaster = true)
+          blockId, new ChunkedByteBuffer(byteBuffer.duplicate()), storageLevel, tellMaster = true,
+          encrypt = true)
       case o =>
         throw new SparkException(
           s"Could not store $blockId to block manager, unexpected block type ${o.getClass.getName}")
@@ -175,10 +176,11 @@ private[streaming] class WriteAheadLogBasedBlockHandler(
     val serializedBlock = block match {
       case ArrayBufferBlock(arrayBuffer) =>
         numRecords = Some(arrayBuffer.size.toLong)
-        serializerManager.dataSerialize(blockId, arrayBuffer.iterator)
+        serializerManager.dataSerialize(blockId, arrayBuffer.iterator, allowEncryption = false)
       case IteratorBlock(iterator) =>
         val countIterator = new CountingIterator(iterator)
-        val serializedBlock = serializerManager.dataSerialize(blockId, countIterator)
+        val serializedBlock = serializerManager.dataSerialize(blockId, countIterator,
+          allowEncryption = false)
         numRecords = countIterator.count
         serializedBlock
       case ByteBufferBlock(byteBuffer) =>
@@ -193,7 +195,8 @@ private[streaming] class WriteAheadLogBasedBlockHandler(
         blockId,
         serializedBlock,
         effectiveStorageLevel,
-        tellMaster = true)
+        tellMaster = true,
+        encrypt = true)
       if (!putSucceeded) {
         throw new SparkException(
           s"Could not store $blockId to block manager with storage level $storageLevel")
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/ReceivedBlockHandlerSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/ReceivedBlockHandlerSuite.scala
index f224193600..c2b0389b8c 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/ReceivedBlockHandlerSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/ReceivedBlockHandlerSuite.scala
@@ -32,10 +32,12 @@ import org.scalatest.concurrent.Eventually._
 import org.apache.spark._
 import org.apache.spark.broadcast.BroadcastManager
 import org.apache.spark.internal.Logging
+import org.apache.spark.internal.config._
 import org.apache.spark.memory.StaticMemoryManager
 import org.apache.spark.network.netty.NettyBlockTransferService
 import org.apache.spark.rpc.RpcEnv
 import org.apache.spark.scheduler.LiveListenerBus
+import org.apache.spark.security.CryptoStreamUtils
 import org.apache.spark.serializer.{KryoSerializer, SerializerManager}
 import org.apache.spark.shuffle.sort.SortShuffleManager
 import org.apache.spark.storage._
@@ -44,7 +46,7 @@ import org.apache.spark.streaming.util._
 import org.apache.spark.util.{ManualClock, Utils}
 import org.apache.spark.util.io.ChunkedByteBuffer
 
-class ReceivedBlockHandlerSuite
+abstract class BaseReceivedBlockHandlerSuite(enableEncryption: Boolean)
   extends SparkFunSuite
   with BeforeAndAfter
   with Matchers
@@ -57,14 +59,22 @@ class ReceivedBlockHandlerSuite
   val conf = new SparkConf()
     .set("spark.streaming.receiver.writeAheadLog.rollingIntervalSecs", "1")
     .set("spark.app.id", "streaming-test")
+    .set(IO_ENCRYPTION_ENABLED, enableEncryption)
+  val encryptionKey =
+    if (enableEncryption) {
+      Some(CryptoStreamUtils.createKey(conf))
+    } else {
+      None
+    }
+
   val hadoopConf = new Configuration()
   val streamId = 1
-  val securityMgr = new SecurityManager(conf)
+  val securityMgr = new SecurityManager(conf, encryptionKey)
   val broadcastManager = new BroadcastManager(true, conf, securityMgr)
   val mapOutputTracker = new MapOutputTrackerMaster(conf, broadcastManager, true)
   val shuffleManager = new SortShuffleManager(conf)
   val serializer = new KryoSerializer(conf)
-  var serializerManager = new SerializerManager(serializer, conf)
+  var serializerManager = new SerializerManager(serializer, conf, encryptionKey)
   val manualClock = new ManualClock
   val blockManagerSize = 10000000
   val blockManagerBuffer = new ArrayBuffer[BlockManager]()
@@ -164,7 +174,9 @@ class ReceivedBlockHandlerSuite
           val bytes = reader.read(fileSegment)
           reader.close()
           serializerManager.dataDeserializeStream(
-            generateBlockId(), new ChunkedByteBuffer(bytes).toInputStream())(ClassTag.Any).toList
+            generateBlockId(),
+            new ChunkedByteBuffer(bytes).toInputStream(),
+            maybeEncrypted = false)(ClassTag.Any).toList
         }
         loggedData shouldEqual data
       }
@@ -208,6 +220,8 @@ class ReceivedBlockHandlerSuite
     sparkConf.set("spark.storage.unrollMemoryThreshold", "512")
     // spark.storage.unrollFraction set to 0.4 for BlockManager
     sparkConf.set("spark.storage.unrollFraction", "0.4")
+
+    sparkConf.set(IO_ENCRYPTION_ENABLED, enableEncryption)
     // Block Manager with 12000 * 0.4 = 4800 bytes of free space for unroll
     blockManager = createBlockManager(12000, sparkConf)
 
@@ -343,7 +357,7 @@ class ReceivedBlockHandlerSuite
     }
 
     def dataToByteBuffer(b: Seq[String]) =
-      serializerManager.dataSerialize(generateBlockId, b.iterator)
+      serializerManager.dataSerialize(generateBlockId, b.iterator, allowEncryption = false)
 
     val blocks = data.grouped(10).toSeq
 
@@ -418,3 +432,6 @@ class ReceivedBlockHandlerSuite
   private def generateBlockId(): StreamBlockId = StreamBlockId(streamId, scala.util.Random.nextLong)
 }
 
+class ReceivedBlockHandlerSuite extends BaseReceivedBlockHandlerSuite(false)
+
+class ReceivedBlockHandlerWithEncryptionSuite extends BaseReceivedBlockHandlerSuite(true)
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDDSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDDSuite.scala
index c5e695a33a..2ac0dc9691 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDDSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/rdd/WriteAheadLogBackedBlockRDDSuite.scala
@@ -24,6 +24,7 @@ import org.apache.hadoop.conf.Configuration
 import org.scalatest.{BeforeAndAfterAll, BeforeAndAfterEach}
 
 import org.apache.spark.{SparkConf, SparkContext, SparkException, SparkFunSuite}
+import org.apache.spark.internal.config._
 import org.apache.spark.serializer.SerializerManager
 import org.apache.spark.storage.{BlockId, BlockManager, StorageLevel, StreamBlockId}
 import org.apache.spark.streaming.util.{FileBasedWriteAheadLogSegment, FileBasedWriteAheadLogWriter}
@@ -45,6 +46,7 @@ class WriteAheadLogBackedBlockRDDSuite
 
   override def beforeEach(): Unit = {
     super.beforeEach()
+    initSparkContext()
     dir = Utils.createTempDir()
   }
 
@@ -56,22 +58,33 @@ class WriteAheadLogBackedBlockRDDSuite
     }
   }
 
-  override def beforeAll(): Unit = {
-    super.beforeAll()
-    sparkContext = new SparkContext(conf)
-    blockManager = sparkContext.env.blockManager
-    serializerManager = sparkContext.env.serializerManager
+  override def afterAll(): Unit = {
+    try {
+      stopSparkContext()
+    } finally {
+      super.afterAll()
+    }
   }
 
-  override def afterAll(): Unit = {
+  private def initSparkContext(_conf: Option[SparkConf] = None): Unit = {
+    if (sparkContext == null) {
+      sparkContext = new SparkContext(_conf.getOrElse(conf))
+      blockManager = sparkContext.env.blockManager
+      serializerManager = sparkContext.env.serializerManager
+    }
+  }
+
+  private def stopSparkContext(): Unit = {
     // Copied from LocalSparkContext, simpler than to introduced test dependencies to core tests.
     try {
-      sparkContext.stop()
+      if (sparkContext != null) {
+        sparkContext.stop()
+      }
       System.clearProperty("spark.driver.port")
       blockManager = null
       serializerManager = null
     } finally {
-      super.afterAll()
+      sparkContext = null
     }
   }
 
@@ -106,6 +119,17 @@ class WriteAheadLogBackedBlockRDDSuite
       numPartitions = 5, numPartitionsInBM = 0, numPartitionsInWAL = 5, testStoreInBM = true)
   }
 
+  test("read data in block manager and WAL with encryption on") {
+    stopSparkContext()
+    try {
+      val testConf = conf.clone().set(IO_ENCRYPTION_ENABLED, true)
+      initSparkContext(Some(testConf))
+      testRDD(numPartitions = 5, numPartitionsInBM = 3, numPartitionsInWAL = 2)
+    } finally {
+      stopSparkContext()
+    }
+  }
+
   /**
    * Test the WriteAheadLogBackedRDD, by writing some partitions of the data to block manager
    * and the rest to a write ahead log, and then reading it all back using the RDD.
@@ -226,7 +250,8 @@ class WriteAheadLogBackedBlockRDDSuite
     require(blockData.size === blockIds.size)
     val writer = new FileBasedWriteAheadLogWriter(new File(dir, "logFile").toString, hadoopConf)
     val segments = blockData.zip(blockIds).map { case (data, id) =>
-      writer.write(serializerManager.dataSerialize(id, data.iterator).toByteBuffer)
+      writer.write(serializerManager.dataSerialize(id, data.iterator, allowEncryption = false)
+        .toByteBuffer)
     }
     writer.close()
     segments