diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/CryptoStreamsTestBase.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/CryptoStreamsTestBase.java
index f5a8ad49ec5..f5acc73b147 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/CryptoStreamsTestBase.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/CryptoStreamsTestBase.java
@@ -28,6 +28,7 @@ import java.util.Random;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.ByteBufferReadable;
+import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.HasEnhancedByteBufferAccess;
 import org.apache.hadoop.fs.PositionedReadable;
 import org.apache.hadoop.fs.ReadOption;
@@ -146,6 +147,25 @@ public abstract class CryptoStreamsTestBase {
     in.close();
   }
   
+  /** Test crypto writing with different buffer size. */
+  @Test(timeout = 120000)
+  public void testWrite() throws Exception {
+    // Default buffer size
+    writeCheck(defaultBufferSize);
+
+    // Small buffer size
+    writeCheck(smallBufferSize);
+  }
+
+  private void writeCheck(int bufferSize) throws Exception {
+    OutputStream out = getOutputStream(bufferSize);
+    writeData(out);
+
+    if (out instanceof FSDataOutputStream) {
+      Assert.assertEquals(((FSDataOutputStream) out).getPos(), getDataLen());
+    }
+  }
+
   /** Test crypto with different IV. */
   @Test(timeout=120000)
   public void testCryptoIV() throws Exception {
diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES-fs-encryption.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES-fs-encryption.txt
index 0b7986a470b..f40841715e5 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES-fs-encryption.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES-fs-encryption.txt
@@ -44,6 +44,8 @@ fs-encryption (Unreleased)
 
     HDFS-6619. Clean up encryption-related tests. (wang)
 
+    HDFS-6405. Test Crypto streams in HDFS. (yliu via wang)
+
   OPTIMIZATIONS
 
   BUG FIXES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/crypto/TestHdfsCryptoStreams.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/crypto/TestHdfsCryptoStreams.java
new file mode 100644
index 00000000000..35c13e65b51
--- /dev/null
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/crypto/TestHdfsCryptoStreams.java
@@ -0,0 +1,91 @@
+/**
+ * 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.hadoop.hdfs.crypto;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.crypto.CryptoCodec;
+import org.apache.hadoop.crypto.CryptoStreamsTestBase;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.crypto.CryptoFSDataInputStream;
+import org.apache.hadoop.fs.crypto.CryptoFSDataOutputStream;
+import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+
+public class TestHdfsCryptoStreams extends CryptoStreamsTestBase {
+  private static MiniDFSCluster dfsCluster;
+  private static FileSystem fs;
+  private static int pathCount = 0;
+  private static Path path;
+  private static Path file;
+
+  @BeforeClass
+  public static void init() throws Exception {
+    Configuration conf = new HdfsConfiguration();
+    dfsCluster = new MiniDFSCluster.Builder(conf).build();
+    dfsCluster.waitClusterUp();
+    fs = dfsCluster.getFileSystem();
+    codec = CryptoCodec.getInstance(conf);
+  }
+
+  @AfterClass
+  public static void shutdown() throws Exception {
+    if (dfsCluster != null) {
+      dfsCluster.shutdown();
+    }
+  }
+
+  @Before
+  @Override
+  public void setUp() throws IOException {
+    ++pathCount;
+    path = new Path("/p" + pathCount);
+    file = new Path(path, "file");
+    FileSystem.mkdirs(fs, path, FsPermission.createImmutable((short) 0700));
+
+    super.setUp();
+  }
+
+  @After
+  public void cleanUp() throws IOException {
+    fs.delete(path, true);
+  }
+
+  @Override
+  protected OutputStream getOutputStream(int bufferSize, byte[] key, byte[] iv)
+      throws IOException {
+    return new CryptoFSDataOutputStream(fs.create(file), codec, bufferSize,
+        key, iv);
+  }
+
+  @Override
+  protected InputStream getInputStream(int bufferSize, byte[] key, byte[] iv)
+      throws IOException {
+    return new CryptoFSDataInputStream(fs.open(file), codec, bufferSize, key,
+        iv);
+  }
+}