2023-03-14 13:16:08 +01:00

334 lines
13 KiB
Java

/*
This class is copied from "apksigner" and I couldn't find the
original repo/author to credit here.
*/
package com.reandroid.archive;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.Enumeration;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipOutputStream;
public class ZipAlign {
private static final int ZIP_ENTRY_HEADER_LEN = 30;
private static final int ZIP_ENTRY_VERSION = 20;
private static final int ZIP_ENTRY_USES_DATA_DESCR = 0x0008;
private static final int ZIP_ENTRY_DATA_DESCRIPTOR_LEN = 16;
private static final int ALIGNMENT_4 = 4;
private static final int ALIGNMENT_PAGE = 4096;
private static class XEntry {
public final ZipEntry entry;
public final long headerOffset;
public final int flags;
public final int padding;
public XEntry(ZipEntry entry, long headerOffset, int flags, int padding) {
this.entry = entry;
this.headerOffset = headerOffset;
this.flags = flags;
this.padding = padding;
}
}
private static class FilterOutputStreamEx extends FilterOutputStream {
private long totalWritten = 0;
public FilterOutputStreamEx(OutputStream out) {
super(out);
}
@Override
public void write(byte[] b) throws IOException {
out.write(b);
totalWritten += b.length;
}
@Override
public void write(byte[] b, int off, int len) throws IOException {
out.write(b, off, len);
totalWritten += len;
}
@Override
public void write(int b) throws IOException {
out.write(b);
totalWritten += 1;
}
@Override
public void close() throws IOException {
super.close();
}
public void writeInt(long v) throws IOException {
write((int) (v & 0xff));
write((int) ((v >>> 8) & 0xff));
write((int) ((v >>> 16) & 0xff));
write((int) ((v >>> 24) & 0xff));
}
public void writeShort(int v) throws IOException {
write((v) & 0xff);
write((v >>> 8) & 0xff);
}
}
private File mInputFile;
private int mAlignment;
private File mOutputFile;
private ZipFile mZipFile;
private RandomAccessFile mRafInput;
private FilterOutputStreamEx mOutputStream;
private final List<XEntry> mXEntries = new ArrayList<>();
private long mInputFileOffset = 0;
private int mTotalPadding = 0;
public void zipAlign(File input, File output) throws IOException {
zipAlign(input, output, ALIGNMENT_4);
}
public void zipAlign(File input, File output, int alignment) throws IOException {
mInputFile = input;
mAlignment = alignment;
mOutputFile = output;
openFiles();
copyAllEntries();
buildCentralDirectory();
closeFiles();
}
private void openFiles() throws IOException {
mZipFile = new ZipFile(mInputFile);
mRafInput = new RandomAccessFile(mInputFile, "r");
mOutputStream = new FilterOutputStreamEx(new BufferedOutputStream(new FileOutputStream(mOutputFile), 32 * 1024));
}
private void copyAllEntries() throws IOException {
final int entryCount = mZipFile.size();
if (entryCount == 0) {
return;
}
final Enumeration<?> entries = mZipFile.entries();
while (entries.hasMoreElements()) {
final ZipEntry entry = (ZipEntry) entries.nextElement();
final String name = entry.getName();
int flags = entry.getMethod() == ZipEntry.STORED ? 0 : 1 << 3;
flags |= 1 << 11;
final long outputEntryHeaderOffset = mOutputStream.totalWritten;
final int inputEntryHeaderSize = ZIP_ENTRY_HEADER_LEN + (entry.getExtra() != null ? entry.getExtra().length : 0)
+ name.getBytes(StandardCharsets.UTF_8).length;
final long inputEntryDataOffset = mInputFileOffset + inputEntryHeaderSize;
final int padding;
if (entry.getMethod() != ZipEntry.STORED) {
padding = 0;
} else {
int alignment = mAlignment;
if (name.startsWith("lib/") && name.endsWith(".so")) {
alignment = ALIGNMENT_PAGE;
}
long newOffset = inputEntryDataOffset + mTotalPadding;
padding = (int) ((alignment - (newOffset % alignment)) % alignment);
mTotalPadding += padding;
}
final XEntry xentry = new XEntry(entry, outputEntryHeaderOffset, flags, padding);
mXEntries.add(xentry);
byte[] extra = entry.getExtra();
if (extra == null) {
extra = new byte[padding];
} else {
byte[] newExtra = new byte[extra.length + padding];
System.arraycopy(extra, 0, newExtra, 0, extra.length);
Arrays.fill(newExtra, extra.length, newExtra.length, (byte) 0);
extra = newExtra;
}
entry.setExtra(extra);
mOutputStream.writeInt(ZipOutputStream.LOCSIG);
mOutputStream.writeShort(ZIP_ENTRY_VERSION);
mOutputStream.writeShort(flags);
mOutputStream.writeShort(entry.getMethod());
int modDate;
int time;
GregorianCalendar cal = new GregorianCalendar();
cal.setTime(new Date(entry.getTime()));
int year = cal.get(Calendar.YEAR);
if (year < 1980) {
modDate = 0x21;
time = 0;
} else {
modDate = cal.get(Calendar.DATE);
modDate = (cal.get(Calendar.MONTH) + 1 << 5) | modDate;
modDate = ((cal.get(Calendar.YEAR) - 1980) << 9) | modDate;
time = cal.get(Calendar.SECOND) >> 1;
time = (cal.get(Calendar.MINUTE) << 5) | time;
time = (cal.get(Calendar.HOUR_OF_DAY) << 11) | time;
}
mOutputStream.writeShort(time);
mOutputStream.writeShort(modDate);
mOutputStream.writeInt(entry.getCrc());
mOutputStream.writeInt(entry.getCompressedSize());
mOutputStream.writeInt(entry.getSize());
mOutputStream.writeShort(entry.getName().getBytes(StandardCharsets.UTF_8).length);
mOutputStream.writeShort(entry.getExtra().length);
mOutputStream.write(entry.getName().getBytes(StandardCharsets.UTF_8));
mOutputStream.write(entry.getExtra(), 0, entry.getExtra().length);
mInputFileOffset += inputEntryHeaderSize;
final long sizeToCopy;
if ((flags & ZIP_ENTRY_USES_DATA_DESCR) != 0) {
sizeToCopy = (entry.isDirectory() ? 0 : entry.getCompressedSize()) + ZIP_ENTRY_DATA_DESCRIPTOR_LEN;
} else {
sizeToCopy = entry.isDirectory() ? 0 : entry.getCompressedSize();
}
if (sizeToCopy > 0) {
mRafInput.seek(mInputFileOffset);
long totalSizeCopied = 0;
final byte[] buf = new byte[32 * 1024];
while (totalSizeCopied < sizeToCopy) {
int read = mRafInput.read(buf, 0, (int) Math.min(32 * 1024, sizeToCopy - totalSizeCopied));
if (read <= 0) {
break;
}
mOutputStream.write(buf, 0, read);
totalSizeCopied += read;
}
}
mInputFileOffset += sizeToCopy;
}
}
private void buildCentralDirectory() throws IOException {
final long centralDirOffset = mOutputStream.totalWritten;
final int entryCount = mXEntries.size();
for (int i = 0; i < entryCount; i++) {
XEntry xentry = mXEntries.get(i);
final ZipEntry entry = xentry.entry;
int modDate;
int time;
GregorianCalendar cal = new GregorianCalendar();
cal.setTime(new Date(entry.getTime()));
int year = cal.get(Calendar.YEAR);
if (year < 1980) {
modDate = 0x21;
time = 0;
} else {
modDate = cal.get(Calendar.DATE);
modDate = (cal.get(Calendar.MONTH) + 1 << 5) | modDate;
modDate = ((cal.get(Calendar.YEAR) - 1980) << 9) | modDate;
time = cal.get(Calendar.SECOND) >> 1;
time = (cal.get(Calendar.MINUTE) << 5) | time;
time = (cal.get(Calendar.HOUR_OF_DAY) << 11) | time;
}
mOutputStream.writeInt(ZipFile.CENSIG); // CEN header signature
mOutputStream.writeShort(ZIP_ENTRY_VERSION); // version made by
mOutputStream.writeShort(ZIP_ENTRY_VERSION); // version needed to extract
mOutputStream.writeShort(xentry.flags); // general purpose bit flag
mOutputStream.writeShort(entry.getMethod()); // compression method
mOutputStream.writeShort(time);
mOutputStream.writeShort(modDate);
mOutputStream.writeInt(entry.getCrc()); // crc-32
mOutputStream.writeInt(entry.getCompressedSize()); // compressed size
mOutputStream.writeInt(entry.getSize()); // uncompressed size
final byte[] nameBytes = entry.getName().getBytes(StandardCharsets.UTF_8);
mOutputStream.writeShort(nameBytes.length);
mOutputStream.writeShort(entry.getExtra() != null ? entry.getExtra().length - xentry.padding : 0);
final byte[] commentBytes;
if (entry.getComment() != null) {
commentBytes = entry.getComment().getBytes(StandardCharsets.UTF_8);
mOutputStream.writeShort(Math.min(commentBytes.length, 0xffff));
} else {
commentBytes = null;
mOutputStream.writeShort(0);
}
mOutputStream.writeShort(0); // starting disk number
mOutputStream.writeShort(0); // internal file attributes (unused)
mOutputStream.writeInt(0); // external file attributes (unused)
mOutputStream.writeInt(xentry.headerOffset); // relative offset of local header
mOutputStream.write(nameBytes);
if (entry.getExtra() != null) {
mOutputStream.write(entry.getExtra(), 0, entry.getExtra().length - xentry.padding);
}
if (commentBytes != null) {
mOutputStream.write(commentBytes, 0, Math.min(commentBytes.length, 0xffff));
}
}
final long centralDirSize = mOutputStream.totalWritten - centralDirOffset;
mOutputStream.writeInt(ZipFile.ENDSIG); // END record signature
mOutputStream.writeShort(0); // number of this disk
mOutputStream.writeShort(0); // central directory start disk
mOutputStream.writeShort(entryCount); // number of directory entries on disk
mOutputStream.writeShort(entryCount); // total number of directory entries
mOutputStream.writeInt(centralDirSize); // length of central directory
mOutputStream.writeInt(centralDirOffset); // offset of central directory
mOutputStream.writeShort(0);
mOutputStream.flush();
}
private void closeFiles() throws IOException {
try {
mZipFile.close();
} finally {
try {
mRafInput.close();
} finally {
mOutputStream.close();
}
}
}
public static void align4(File inFile) throws IOException{
align(inFile, ALIGNMENT_4);
}
public static void align4(File inFile, File outFile) throws IOException{
align(inFile, outFile, ALIGNMENT_4);
}
public static void align(File inFile, int alignment) throws IOException{
File tmp=toTmpFile(inFile);
tmp.delete();
align(inFile, tmp, alignment);
inFile.delete();
tmp.renameTo(inFile);
}
public static void align(File inFile, File outFile, int alignment) throws IOException{
ZipAlign zipAlign=new ZipAlign();
File dir=outFile.getParentFile();
if(dir!=null && !dir.exists()){
dir.mkdirs();
}
zipAlign.zipAlign(inFile, outFile, alignment);
}
private static File toTmpFile(File file){
String name=file.getName()+".align.tmp";
File dir=file.getParentFile();
if(dir==null){
return new File(name);
}
return new File(dir, name);
}
}