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From bode...@apache.org
Subject [1/2] commons-compress git commit: COMPRESS-271 verify block checksums
Date Thu, 09 Feb 2017 16:37:34 GMT
Repository: commons-compress
Updated Branches:
  refs/heads/master 72fec65e1 -> e79465bbe


COMPRESS-271 verify block checksums


Project: http://git-wip-us.apache.org/repos/asf/commons-compress/repo
Commit: http://git-wip-us.apache.org/repos/asf/commons-compress/commit/982ce0ec
Tree: http://git-wip-us.apache.org/repos/asf/commons-compress/tree/982ce0ec
Diff: http://git-wip-us.apache.org/repos/asf/commons-compress/diff/982ce0ec

Branch: refs/heads/master
Commit: 982ce0eca9935e65915278ae07febd3a1d52273d
Parents: 72fec65
Author: Stefan Bodewig <bodewig@apache.org>
Authored: Thu Feb 9 17:37:01 2017 +0100
Committer: Stefan Bodewig <bodewig@apache.org>
Committed: Thu Feb 9 17:37:01 2017 +0100

----------------------------------------------------------------------
 .../lz4/FramedLZ4CompressorInputStream.java     | 38 +++++---
 .../utils/ChecksumCalculatingInputStream.java   | 97 ++++++++++++++++++++
 2 files changed, 120 insertions(+), 15 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/commons-compress/blob/982ce0ec/src/main/java/org/apache/commons/compress/compressors/lz4/FramedLZ4CompressorInputStream.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/commons/compress/compressors/lz4/FramedLZ4CompressorInputStream.java
b/src/main/java/org/apache/commons/compress/compressors/lz4/FramedLZ4CompressorInputStream.java
index 9b47d7b..8bf49ac 100644
--- a/src/main/java/org/apache/commons/compress/compressors/lz4/FramedLZ4CompressorInputStream.java
+++ b/src/main/java/org/apache/commons/compress/compressors/lz4/FramedLZ4CompressorInputStream.java
@@ -25,6 +25,7 @@ import java.util.Arrays;
 import org.apache.commons.compress.compressors.CompressorInputStream;
 import org.apache.commons.compress.utils.BoundedInputStream;
 import org.apache.commons.compress.utils.ByteUtils;
+import org.apache.commons.compress.utils.ChecksumCalculatingInputStream;
 import org.apache.commons.compress.utils.IOUtils;
 
 /**
@@ -80,6 +81,9 @@ public class FramedLZ4CompressorInputStream extends CompressorInputStream
{
     // used for frame header checksum and content checksum, if present
     private final XXHash32 contentHash = new XXHash32();
 
+    // used for block checksum, if present
+    private final XXHash32 blockHash = new XXHash32();
+
     // only created if the frame doesn't set the block independence flag
     private byte[] blockDependencyBuffer;
 
@@ -239,6 +243,9 @@ public class FramedLZ4CompressorInputStream extends CompressorInputStream
{
             return;
         }
         InputStream capped = new BoundedInputStream(in, realLen);
+        if (expectBlockChecksum) {
+            capped = new ChecksumCalculatingInputStream(blockHash, capped);
+        }
         if (uncompressed) {
             inUncompressed = true;
             currentBlock = capped;
@@ -257,31 +264,32 @@ public class FramedLZ4CompressorInputStream extends CompressorInputStream
{
             currentBlock.close();
             currentBlock = null;
             if (expectBlockChecksum) {
-                int skipped = (int) IOUtils.skip(in, 4);
-                count(skipped);
-                if (4 != skipped) {
-                    throw new IOException("Premature end of stream while reading block checksum");
-                }
+                verifyChecksum(blockHash, "block");
+                blockHash.reset();
             }
         }
     }
 
     private void verifyContentChecksum() throws IOException {
         if (expectContentChecksum) {
-            byte[] checksum = new byte[4];
-            int read = IOUtils.readFully(in, checksum);
-            count(read);
-            if (4 != read) {
-                throw new IOException("Premature end of stream while reading content checksum");
-            }
-            long expectedHash = contentHash.getValue();
-            if (expectedHash != ByteUtils.fromLittleEndian(checksum)) {
-                throw new IOException("content checksum mismatch.");
-            }
+            verifyChecksum(contentHash, "content");
         }
         contentHash.reset();
     }
 
+    private void verifyChecksum(XXHash32 hash, String kind) throws IOException {
+        byte[] checksum = new byte[4];
+        int read = IOUtils.readFully(in, checksum);
+        count(read);
+        if (4 != read) {
+            throw new IOException("Premature end of stream while reading " + kind + " checksum");
+        }
+        long expectedHash = hash.getValue();
+        if (expectedHash != ByteUtils.fromLittleEndian(checksum)) {
+            throw new IOException(kind + " checksum mismatch.");
+        }
+    }
+
     private int readOneByte() throws IOException {
         final int b = in.read();
         if (b != -1) {

http://git-wip-us.apache.org/repos/asf/commons-compress/blob/982ce0ec/src/main/java/org/apache/commons/compress/utils/ChecksumCalculatingInputStream.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/commons/compress/utils/ChecksumCalculatingInputStream.java
b/src/main/java/org/apache/commons/compress/utils/ChecksumCalculatingInputStream.java
new file mode 100644
index 0000000..a698196
--- /dev/null
+++ b/src/main/java/org/apache/commons/compress/utils/ChecksumCalculatingInputStream.java
@@ -0,0 +1,97 @@
+/*
+ *  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.commons.compress.utils;
+
+import java.io.FilterInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.zip.Checksum;
+
+/**
+ * A stream that calculates the checksum of the data read.
+ * @NotThreadSafe
+ * @since 1.14
+ */
+public class ChecksumCalculatingInputStream extends InputStream {
+    private final InputStream in;
+    private final Checksum checksum;
+
+    public ChecksumCalculatingInputStream(final Checksum checksum, final InputStream in)
{
+        this.checksum = checksum;
+        this.in = in;
+    }
+
+    /**
+     * Reads a single byte from the stream
+     * @throws IOException if the underlying stream throws or the
+     * stream is exhausted and the Checksum doesn't match the expected
+     * value
+     */
+    @Override
+    public int read() throws IOException {
+        final int ret = in.read();
+        if (ret >= 0) {
+            checksum.update(ret);
+        }
+        return ret;
+    }
+
+    /**
+     * Reads a byte array from the stream
+     * @throws IOException if the underlying stream throws or the
+     * stream is exhausted and the Checksum doesn't match the expected
+     * value
+     */
+    @Override
+    public int read(final byte[] b) throws IOException {
+        return read(b, 0, b.length);
+    }
+
+    /**
+     * Reads from the stream into a byte array.
+     * @throws IOException if the underlying stream throws or the
+     * stream is exhausted and the Checksum doesn't match the expected
+     * value
+     */
+    @Override
+    public int read(final byte[] b, final int off, final int len) throws IOException {
+        final int ret = in.read(b, off, len);
+        if (ret >= 0) {
+            checksum.update(b, off, ret);
+        }
+        return ret;
+    }
+
+    @Override
+    public long skip(final long n) throws IOException {
+        // Can't really skip, we have to hash everything to verify the checksum
+        if (read() >= 0) {
+            return 1;
+        }
+        return 0;
+    }
+
+    /**
+     * Returns the calculated checksum.
+     * @return the calculated checksum.
+     */
+    public long getValue() {
+        return checksum.getValue();
+    }
+
+}


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