src.org.tukaani.xz.index.IndexHash Maven / Gradle / Ivy
/*
* IndexHash
*
* Author: Lasse Collin
*
* This file has been put into the public domain.
* You can do whatever you want with this file.
*/
package org.tukaani.xz.index;
import java.io.InputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.zip.CheckedInputStream;
import org.tukaani.xz.common.DecoderUtil;
import org.tukaani.xz.XZIOException;
import org.tukaani.xz.CorruptedInputException;
public class IndexHash extends IndexBase {
private org.tukaani.xz.check.Check hash;
public IndexHash() {
super(new CorruptedInputException());
try {
hash = new org.tukaani.xz.check.SHA256();
} catch (java.security.NoSuchAlgorithmException e) {
hash = new org.tukaani.xz.check.CRC32();
}
}
public void add(long unpaddedSize, long uncompressedSize)
throws XZIOException {
super.add(unpaddedSize, uncompressedSize);
ByteBuffer buf = ByteBuffer.allocate(2 * 8);
buf.putLong(unpaddedSize);
buf.putLong(uncompressedSize);
hash.update(buf.array());
}
public void validate(InputStream in) throws IOException {
// Index Indicator (0x00) has already been read by BlockInputStream
// so add 0x00 to the CRC32 here.
java.util.zip.CRC32 crc32 = new java.util.zip.CRC32();
crc32.update('\0');
CheckedInputStream inChecked = new CheckedInputStream(in, crc32);
// Get and validate the Number of Records field.
long storedRecordCount = DecoderUtil.decodeVLI(inChecked);
if (storedRecordCount != recordCount)
throw new CorruptedInputException("XZ Index is corrupt");
// Decode and hash the Index field and compare it to
// the hash value calculated from the decoded Blocks.
IndexHash stored = new IndexHash();
for (long i = 0; i < recordCount; ++i) {
long unpaddedSize = DecoderUtil.decodeVLI(inChecked);
long uncompressedSize = DecoderUtil.decodeVLI(inChecked);
try {
stored.add(unpaddedSize, uncompressedSize);
} catch (XZIOException e) {
throw new CorruptedInputException("XZ Index is corrupt");
}
if (stored.blocksSum > blocksSum
|| stored.uncompressedSum > uncompressedSum
|| stored.indexListSize > indexListSize)
throw new CorruptedInputException("XZ Index is corrupt");
}
if (stored.blocksSum != blocksSum
|| stored.uncompressedSum != uncompressedSum
|| stored.indexListSize != indexListSize
|| !Arrays.equals(stored.hash.finish(), hash.finish()))
throw new CorruptedInputException("XZ Index is corrupt");
// Index Padding
DataInputStream inData = new DataInputStream(inChecked);
for (int i = getIndexPaddingSize(); i > 0; --i)
if (inData.readUnsignedByte() != 0x00)
throw new CorruptedInputException("XZ Index is corrupt");
// CRC32
long value = crc32.getValue();
for (int i = 0; i < 4; ++i)
if (((value >>> (i * 8)) & 0xFF) != inData.readUnsignedByte())
throw new CorruptedInputException("XZ Index is corrupt");
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy