/**
* Appends a zip64 extended info record to the extras contained in {@code ze}. If {@code ze}
* contains no extras, a new extras array is created.
*/
public static void insertZip64ExtendedInfoToExtras(ZipEntry ze) throws ZipException {
final byte[] output;
// We always write the size, uncompressed size and local rel header offset in all our
// Zip64 extended info headers (in both the local file header as well as the central
// directory). We always omit the disk number because we don't support spanned
// archives anyway.
//
// 2 bytes : Zip64 Extended Info Header ID
// 2 bytes : Zip64 Extended Info Field Size.
// 8 bytes : Uncompressed size
// 8 bytes : Compressed size
// 8 bytes : Local header rel offset.
// ----------
// 28 bytes : total
final int extendedInfoSize = 28;
if (ze.extra == null) {
output = new byte[extendedInfoSize];
} else {
// If the existing extras are already too big, we have no choice but to throw
// an error.
if (ze.extra.length + extendedInfoSize > 65535) {
throw new ZipException("No space in extras for zip64 extended entry info");
}
// We copy existing extras over and put the zip64 extended info at the beginning. This
// is to avoid breakages in the presence of "old style" extras which don't contain
// headers and lengths. The spec is again silent about these inconsistencies.
//
// This means that people that for ZipOutputStream users, the value ZipEntry.getExtra
// after an entry is written will be different from before. This shouldn't be an issue
// in practice.
output = new byte[ze.extra.length + extendedInfoSize];
System.arraycopy(ze.extra, 0, output, extendedInfoSize, ze.extra.length);
}
ByteBuffer bb = ByteBuffer.wrap(output).order(ByteOrder.LITTLE_ENDIAN);
bb.putShort(ZIP64_EXTENDED_INFO_HEADER_ID);
// We subtract four because extendedInfoSize includes the ID and field
// size itself.
bb.putShort((short) (extendedInfoSize - 4));
if (ze.getMethod() == ZipEntry.STORED) {
bb.putLong(ze.size);
bb.putLong(ze.compressedSize);
} else {
// Store these fields in the data descriptor instead.
bb.putLong(0); // size.
bb.putLong(0); // compressed size.
}
// The offset is only relevant in the central directory entry, but we write it out here
// anyway, since we know what it is.
bb.putLong(ze.localHeaderRelOffset);
ze.extra = output;
}
/** Returns a deep copy of this zip entry. */
@Override
public Object clone() {
try {
ZipEntry result = (ZipEntry) super.clone();
result.extra = extra != null ? extra.clone() : null;
return result;
} catch (CloneNotSupportedException e) {
throw new AssertionError(e);
}
}
/** Returns a copy of this entry. */
public Object clone() {
try {
ZipEntry e = (ZipEntry) super.clone();
e.extra = (extra == null) ? null : extra.clone();
return e;
} catch (CloneNotSupportedException e) {
// This should never happen, since we are Cloneable
throw new InternalError();
}
}
/**
* Parse the zip64 extended info record from the extras present in {@code ze}.
*
* <p>If {@code fromCentralDirectory} is true, we assume we're parsing a central directory record.
* We assume a local file header otherwise. The difference between the two is that a central
* directory entry is required to be complete, whereas a local file header isn't. This is due to
* the presence of an optional data descriptor after the file content.
*
* @return {@code} true iff. a zip64 extended info record was found.
*/
public static boolean parseZip64ExtendedInfo(ZipEntry ze, boolean fromCentralDirectory)
throws ZipException {
int extendedInfoSize = -1;
int extendedInfoStart = -1;
// If this file contains a zip64 central directory locator, entries might
// optionally contain a zip64 extended information extra entry.
if (ze.extra != null && ze.extra.length > 0) {
// Extensible data fields are of the form header1+data1 + header2+data2 and so
// on, where each header consists of a 2 byte header ID followed by a 2 byte size.
// We need to iterate through the entire list of headers to find the header ID
// for the zip64 extended information extra field (0x0001).
final ByteBuffer buf = ByteBuffer.wrap(ze.extra).order(ByteOrder.LITTLE_ENDIAN);
extendedInfoSize = getZip64ExtendedInfoSize(buf);
if (extendedInfoSize != -1) {
extendedInfoStart = buf.position();
try {
// The size & compressed size only make sense in the central directory *or* if
// we know them beforehand. If we don't know them beforehand, they're stored in
// the data descriptor and should be read from there.
//
// Note that the spec says that the local file header "MUST" contain the
// original and compressed size fields. We don't care too much about that.
// The spec claims that the order of fields is fixed anyway.
if (fromCentralDirectory || (ze.getMethod() == ZipEntry.STORED)) {
if (ze.size == MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE) {
ze.size = buf.getLong();
}
if (ze.compressedSize == MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE) {
ze.compressedSize = buf.getLong();
}
}
// The local header offset is significant only in the central directory. It makes no
// sense within the local header itself.
if (fromCentralDirectory) {
if (ze.localHeaderRelOffset == MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE) {
ze.localHeaderRelOffset = buf.getLong();
}
}
} catch (BufferUnderflowException bue) {
ZipException zipException = new ZipException("Error parsing extended info");
zipException.initCause(bue);
throw zipException;
}
}
}
// This entry doesn't contain a zip64 extended information data entry header.
// We have to check that the compressedSize / size / localHeaderRelOffset values
// are valid and don't require the presence of the extended header.
if (extendedInfoSize == -1) {
if (ze.compressedSize == MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE
|| ze.size == MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE
|| ze.localHeaderRelOffset == MAX_ZIP_ENTRY_AND_ARCHIVE_SIZE) {
throw new ZipException(
"File contains no zip64 extended information: "
+ "name="
+ ze.name
+ "compressedSize="
+ ze.compressedSize
+ ", size="
+ ze.size
+ ", localHeader="
+ ze.localHeaderRelOffset);
}
return false;
} else {
// If we're parsed the zip64 extended info header, we remove it from the extras
// so that applications that set their own extras will see the data they set.
// This is an unfortunate workaround needed due to a gap in the spec. The spec demands
// that extras are present in the "extensible" format, which means that each extra field
// must be prefixed with a header ID and a length. However, earlier versions of the spec
// made no mention of this, nor did any existing API enforce it. This means users could
// set "free form" extras without caring very much whether the implementation wanted to
// extend or add to them.
// The start of the extended info header.
final int extendedInfoHeaderStart = extendedInfoStart - 4;
// The total size of the extended info, including the header.
final int extendedInfoTotalSize = extendedInfoSize + 4;
final int extrasLen = ze.extra.length - extendedInfoTotalSize;
byte[] extrasWithoutZip64 = new byte[extrasLen];
System.arraycopy(ze.extra, 0, extrasWithoutZip64, 0, extendedInfoHeaderStart);
System.arraycopy(
ze.extra,
extendedInfoHeaderStart + extendedInfoTotalSize,
extrasWithoutZip64,
extendedInfoHeaderStart,
(extrasLen - extendedInfoHeaderStart));
ze.extra = extrasWithoutZip64;
return true;
}
}