/*
* Copyright 2016, Google Inc.
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*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jf.dexlib2.util;
import com.google.common.io.ByteStreams;
import org.jf.dexlib2.dexbacked.DexBackedDexFile.NotADexFile;
import org.jf.dexlib2.dexbacked.DexBackedOdexFile.NotAnOdexFile;
import org.jf.dexlib2.dexbacked.raw.HeaderItem;
import org.jf.dexlib2.dexbacked.raw.OdexHeaderItem;
import javax.annotation.Nonnull;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
public class DexUtil {
/**
* Reads in the dex header from the given input stream and verifies that it is valid and a supported version
*
* The inputStream must support mark(), and will be reset to initial position upon exiting the method
*
* @param inputStream An input stream that is positioned at a dex header
* @throws NotADexFile If the file is not a dex file
* @throws InvalidFile If the header appears to be a dex file, but is not valid for some reason
* @throws UnsupportedFile If the dex header is valid, but uses unsupported functionality
*/
public static void verifyDexHeader(@Nonnull InputStream inputStream) throws IOException {
if (!inputStream.markSupported()) {
throw new IllegalArgumentException("InputStream must support mark");
}
inputStream.mark(44);
byte[] partialHeader = new byte[44];
try {
ByteStreams.readFully(inputStream, partialHeader);
} catch (EOFException ex) {
throw new NotADexFile("File is too short");
} finally {
inputStream.reset();
}
verifyDexHeader(partialHeader, 0);
}
/**
* Verifies that the dex header is valid and a supported version
*
* @param buf A byte array containing at least the first 44 bytes of a dex file
* @param offset The offset within the array to the dex header
* @throws NotADexFile If the file is not a dex file
* @throws InvalidFile If the header appears to be a dex file, but is not valid for some reason
* @throws UnsupportedFile If the dex header is valid, but uses unsupported functionality
*/
public static void verifyDexHeader(@Nonnull byte[] buf, int offset) {
int dexVersion = HeaderItem.getVersion(buf, offset);
if (dexVersion == -1) {
StringBuilder sb = new StringBuilder("Not a valid dex magic value:");
for (int i=0; i<8; i++) {
sb.append(String.format(" %02x", buf[i]));
}
throw new NotADexFile(sb.toString());
}
if (!HeaderItem.isSupportedDexVersion(dexVersion)) {
throw new UnsupportedFile(String.format("Dex version %03d is not supported", dexVersion));
}
int endian = HeaderItem.getEndian(buf, offset);
if (endian == HeaderItem.BIG_ENDIAN_TAG) {
throw new UnsupportedFile("Big endian dex files are not supported");
}
if (endian != HeaderItem.LITTLE_ENDIAN_TAG) {
throw new InvalidFile(String.format("Invalid endian tag: 0x%x", endian));
}
}
/**
* Reads in the odex header from the given input stream and verifies that it is valid and a supported version
*
* The inputStream must support mark(), and will be reset to initial position upon exiting the method
*
* @param inputStream An input stream that is positioned at an odex header
* @throws NotAnOdexFile If the file is not an odex file
* @throws UnsupportedFile If the odex header is valid, but is an unsupported version
*/
public static void verifyOdexHeader(@Nonnull InputStream inputStream) throws IOException {
if (!inputStream.markSupported()) {
throw new IllegalArgumentException("InputStream must support mark");
}
inputStream.mark(8);
byte[] partialHeader = new byte[8];
try {
ByteStreams.readFully(inputStream, partialHeader);
} catch (EOFException ex) {
throw new NotAnOdexFile("File is too short");
} finally {
inputStream.reset();
}
verifyOdexHeader(partialHeader, 0);
}
/**
* Verifies that the odex header is valid and a supported version
*
* @param buf A byte array containing at least the first 8 bytes of an odex file
* @param offset The offset within the array to the odex header
* @throws NotAnOdexFile If the file is not an odex file
* @throws UnsupportedFile If the odex header is valid, but uses unsupported functionality
*/
public static void verifyOdexHeader(@Nonnull byte[] buf, int offset) {
int odexVersion = OdexHeaderItem.getVersion(buf, offset);
if (odexVersion == -1) {
StringBuilder sb = new StringBuilder("Not a valid odex magic value:");
for (int i=0; i<8; i++) {
sb.append(String.format(" %02x", buf[i]));
}
throw new NotAnOdexFile(sb.toString());
}
if (!OdexHeaderItem.isSupportedOdexVersion(odexVersion)) {
throw new UnsupportedFile(String.format("Odex version %03d is not supported", odexVersion));
}
}
public static class InvalidFile extends RuntimeException {
public InvalidFile() {
}
public InvalidFile(String message) {
super(message);
}
public InvalidFile(String message, Throwable cause) {
super(message, cause);
}
public InvalidFile(Throwable cause) {
super(cause);
}
}
public static class UnsupportedFile extends RuntimeException {
public UnsupportedFile() {
}
public UnsupportedFile(String message) {
super(message);
}
public UnsupportedFile(String message, Throwable cause) {
super(message, cause);
}
public UnsupportedFile(Throwable cause) {
super(cause);
}
}
}