HADOOP-11040. Return value of read(ByteBuffer buf) in CryptoInputStream is incorrect in some cases. (Yi Liu via wang)

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -732,6 +732,9 @@ Release 2.6.0 - UNRELEASED
     HDFS-7075. hadoop-fuse-dfs fails because it cannot find
     JavaKeyStoreProvider$Factory (cmccabe)
 
+    HADOOP-11040. Return value of read(ByteBuffer buf) in CryptoInputStream is
+    incorrect in some cases. (Yi Liu via wang)
+
     BREAKDOWN OF HDFS-6134 AND HADOOP-10150 SUBTASKS AND RELATED JIRAS
   
       HADOOP-10734. Implement high-performance secure random number sources.

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/crypto/CryptoInputStream.java

@@ -471,7 +471,16 @@ public class CryptoInputStream extends FilterInputStream implements
         streamOffset += n; // Read n bytes
         decrypt(buf, n, pos);
       }
-      return n;
+      
+      if (n >= 0) {
+        return unread + n;
+      } else {
+        if (unread == 0) {
+          return -1;
+        } else {
+          return unread;
+        }
+      }
     }
 
     throw new UnsupportedOperationException("ByteBuffer read unsupported " +

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/crypto/CryptoStreamsTestBase.java

@@ -469,6 +469,7 @@ public abstract class CryptoStreamsTestBase {
       int bufPos) throws Exception {
     buf.position(bufPos);
     int n = ((ByteBufferReadable) in).read(buf);
+    Assert.assertEquals(bufPos + n, buf.position());
     byte[] readData = new byte[n];
     buf.rewind();
     buf.position(bufPos);
@@ -568,6 +569,7 @@ public abstract class CryptoStreamsTestBase {
     // Read forward len1
     ByteBuffer buf = ByteBuffer.allocate(len1);
     int nRead = ((ByteBufferReadable) in).read(buf);
+    Assert.assertEquals(nRead, buf.position());
     readData = new byte[nRead];
     buf.rewind();
     buf.get(readData);
@@ -575,9 +577,10 @@ public abstract class CryptoStreamsTestBase {
     System.arraycopy(data, (int)pos, expectedData, 0, nRead);
     Assert.assertArrayEquals(readData, expectedData);
     
-    // Pos should be len1 + 2 * len2 + nRead
+    long lastPos = pos;
+    // Pos should be lastPos + nRead
     pos = ((Seekable) in).getPos();
-    Assert.assertEquals(len1 + 2 * len2 + nRead, pos);
+    Assert.assertEquals(lastPos + nRead, pos);
     
     // Pos: 1/3 dataLen
     positionedReadCheck(in , dataLen / 3);
@@ -589,13 +592,15 @@ public abstract class CryptoStreamsTestBase {
     System.arraycopy(data, (int)pos, expectedData, 0, len1);
     Assert.assertArrayEquals(readData, expectedData);
     
-    // Pos should be 2 * len1 + 2 * len2 + nRead
+    lastPos = pos;
+    // Pos should be lastPos + len1
     pos = ((Seekable) in).getPos();
-    Assert.assertEquals(2 * len1 + 2 * len2 + nRead, pos);
+    Assert.assertEquals(lastPos + len1, pos);
     
     // Read forward len1
     buf = ByteBuffer.allocate(len1);
     nRead = ((ByteBufferReadable) in).read(buf);
+    Assert.assertEquals(nRead, buf.position());
     readData = new byte[nRead];
     buf.rewind();
     buf.get(readData);
@@ -603,6 +608,11 @@ public abstract class CryptoStreamsTestBase {
     System.arraycopy(data, (int)pos, expectedData, 0, nRead);
     Assert.assertArrayEquals(readData, expectedData);
     
+    lastPos = pos;
+    // Pos should be lastPos + nRead
+    pos = ((Seekable) in).getPos();
+    Assert.assertEquals(lastPos + nRead, pos);
+    
     // ByteBuffer read after EOF
     ((Seekable) in).seek(dataLen);
     buf.clear();