Skip to content

Commit

Permalink
fix: replace patched zip early in input files (#2302)
Browse files Browse the repository at this point in the history
  • Loading branch information
@skylot
skylot committed Oct 12, 2024
1 parent c5263f9 commit b872ffd
Show file tree
Hide file tree
Showing 3 changed files with 207 additions and 176 deletions.
5 changes: 4 additions & 1 deletion jadx-core/src/main/java/jadx/api/JadxDecompiler.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@
import jadx.core.utils.Utils;
import jadx.core.utils.exceptions.JadxRuntimeException;
import jadx.core.utils.files.FileUtils;
import jadx.core.utils.files.ZipPatch;
import jadx.core.utils.tasks.TaskExecutor;
import jadx.core.xmlgen.ResourcesSaver;

Expand Down Expand Up @@ -141,7 +142,9 @@ public void reloadPasses() {

private void loadInputFiles() {
loadedInputs.clear();
List<Path> inputPaths = Utils.collectionMap(args.getInputFiles(), File::toPath);
List<File> inputs = ZipPatch.patchZipFiles(args.getInputFiles());
args.setInputFiles(inputs);
List<Path> inputPaths = Utils.collectionMap(inputs, File::toPath);
List<Path> inputFiles = FileUtils.expandDirs(inputPaths);
long start = System.currentTimeMillis();
for (PluginContext plugin : pluginManager.getResolvedPluginContexts()) {
Expand Down
179 changes: 4 additions & 175 deletions jadx-core/src/main/java/jadx/core/utils/files/ZipFile.java
View file
Original file line number Diff line number Diff line change
@@ -1,17 +1,13 @@
package jadx.core.utils.files;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.lang.reflect.UndeclaredThrowableException;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
* Deprecated zip file wrapper
*/
public class ZipFile extends java.util.zip.ZipFile {

public ZipFile(File file) throws IOException {
Expand All @@ -31,173 +27,6 @@ public ZipFile(String name) throws IOException {
}

public ZipFile(File file, int mode, Charset charset) throws IOException {
super(patchZipFile(file), mode, charset);
}

private static File patchZipFile(File file) throws IOException {
if (!file.getPath().toLowerCase().endsWith(".apk")) {
return file;
}

var cDirEntriesToFix = new ArrayList<Long>();
var localHeaders = new ArrayList<Long>();
List<Long> localHeaderToFix;

try (var raFile = new RandomAccessFile(file, "r")) {
var endOfCDirOffset = findEndOfCentralDir(raFile);

raFile.seek(endOfCDirOffset + 0x10);
var cDirOffset = Integer.toUnsignedLong(Integer.reverseBytes(raFile.readInt()));
raFile.seek(endOfCDirOffset + 0x0a);
var cDirNumEntries = Short.toUnsignedLong(Short.reverseBytes(raFile.readShort()));

for (long i = 0, off = cDirOffset; i < cDirNumEntries; i++) {
var info = readHeader(raFile, off);

if (!info.validCompression()) {
cDirEntriesToFix.add(off);
}

raFile.seek(off + 0x2a);
localHeaders.add(Integer.toUnsignedLong(Integer.reverseBytes(raFile.readInt())));

off += info.dataOffset;
}

localHeaderToFix = localHeaders
.stream()
.filter(off -> !readHeaderVexxed(raFile, off).validCompression())
.collect(Collectors.toList());

if (cDirEntriesToFix.isEmpty() && localHeaderToFix.isEmpty()) {
return file;
}
}

var newFile = copyFile(file);

try (var newRaFile = new RandomAccessFile(newFile, "rwd")) {

for (var off : cDirEntriesToFix) {
var info = readHeader(newRaFile, off);

newRaFile.seek(off + 0x0a);
newRaFile.writeShort(0);

newRaFile.seek(off + 0x14);
newRaFile.writeInt(Integer.reverseBytes((int) info.uncompressedSize));

}

for (var off : localHeaderToFix) {
var info = readHeader(newRaFile, off);

newRaFile.seek(off + 0x08);
newRaFile.writeShort(0);

newRaFile.seek(off + 0x12);
newRaFile.writeInt(Integer.reverseBytes((int) info.uncompressedSize));

newRaFile.seek(off + 0x1c);
newRaFile.writeShort(0);

moveBlockBack(newRaFile, off + info.dataOffset, info.uncompressedSize, info.extraLen);
}
}

return newFile;
}

private static void moveBlockBack(RandomAccessFile file, long offset, long size, long delta) throws IOException {
var buffer = new byte[1024 * 1024];

while (size > 0) {
var len = (int) Math.min(buffer.length, size);

file.seek(offset);
file.read(buffer, 0, len);
file.seek(offset - delta);
file.write(buffer, 0, len);

size -= len;
offset += len;
}
}

private static File copyFile(File file) throws IOException {
var newFile = FileUtils.createTempFile(file.getName()).toFile();
try (var in = new FileInputStream(file)) {
try (var out = new FileOutputStream(newFile)) {
in.transferTo(out);
}
}
return newFile;
}

private static long findEndOfCentralDir(RandomAccessFile file) throws IOException {
var offset = file.length() - 0x15L + 1;

do {
if (offset <= 0) {
throw new IllegalArgumentException("File is not a valid ZIP: End of central directory record not found");
}
file.seek(--offset);
} while (Integer.reverseBytes(file.readInt()) != 0x06054b50);

return offset;
}

private static class HeaderInfo {
short compression;
long uncompressedSize;
long dataOffset;
long extraLen;

boolean validCompression() {
return compression == 0x0 || compression == 0x8;
}
}

private static HeaderInfo readHeaderVexxed(RandomAccessFile file, long offset) {
try {
return readHeader(file, offset);
} catch (IOException e) {
throw new UndeclaredThrowableException(e);
}
}

private static HeaderInfo readHeader(RandomAccessFile file, long offset) throws IOException {
var info = new HeaderInfo();

file.seek(offset);
var signature = Integer.reverseBytes(file.readInt());

if (signature != 0x02014b50 && signature != 0x04034b50) {
throw new IllegalArgumentException(
String.format("Invalid ZIP header signature %x at offset %x",
signature, offset));
}

var isCentralHeader = signature == 0x02014b50;
var delta = isCentralHeader ? 0 : -2;

file.seek(offset + 0x0a + delta);
info.compression = Short.reverseBytes(file.readShort());

file.seek(offset + 0x18 + delta);
info.uncompressedSize = Integer.toUnsignedLong(Integer.reverseBytes(file.readInt()));

file.seek(offset + 0x1c + delta);
var nameLen = Short.toUnsignedLong(Short.reverseBytes(file.readShort()));
info.extraLen = Short.toUnsignedLong(Short.reverseBytes(file.readShort()));
var commentLen = 0L;

if (isCentralHeader) {
commentLen = Short.toUnsignedLong(Short.reverseBytes(file.readShort()));
}

info.dataOffset = (isCentralHeader ? 0x2e : 0x1e) + nameLen + info.extraLen + commentLen;

return info;
super(file, mode, charset);
}
}
Loading

0 comments on commit b872ffd

Please sign in to comment.