/// <summary>
/// Test a local header against that provided from the central directory
/// </summary>
/// <param name="entry">
/// The entry to test against
/// </param>
/// <param name="tests">The type of <see cref="HeaderTest">tests</see> to carry out.</param>
/// <returns>The offset of the entries data in the file</returns>
long TestLocalHeader(ZipEntry entry, HeaderTest tests)
{
lock(baseStream_)
{
bool testHeader = (tests & HeaderTest.Header) != 0;
bool testData = (tests & HeaderTest.Extract) != 0;
baseStream_.Seek(offsetOfFirstEntry + entry.Offset, SeekOrigin.Begin);
if ((int)ReadLEUint() != ZipConstants.LocalHeaderSignature) {
}
short extractVersion = ( short )ReadLEUshort();
short localFlags = ( short )ReadLEUshort();
short compressionMethod = ( short )ReadLEUshort();
short fileTime = ( short )ReadLEUshort();
short fileDate = ( short )ReadLEUshort();
uint crcValue = ReadLEUint();
long compressedSize = ReadLEUint();
long size = ReadLEUint();
int storedNameLength = ReadLEUshort();
int extraDataLength = ReadLEUshort();
byte[] nameData = new byte[storedNameLength];
StreamUtils.ReadFully(baseStream_, nameData);
byte[] extraData = new byte[extraDataLength];
StreamUtils.ReadFully(baseStream_, extraData);
ZipExtraData localExtraData = new ZipExtraData(extraData);
// Extra data / zip64 checks
if (localExtraData.Find(1))
{
// 2010-03-04 Forum 10512: removed checks for version >= ZipConstants.VersionZip64
// and size or compressedSize = MaxValue, due to rogue creators.
size = localExtraData.ReadLong();
compressedSize = localExtraData.ReadLong();
if ((localFlags & (int)GeneralBitFlags.Descriptor) != 0)
{
// These may be valid if patched later
if ( (size != -1) && (size != entry.Size)) {
}
if ((compressedSize != -1) && (compressedSize != entry.CompressedSize)) {
}
}
}
else
{
// No zip64 extra data but entry requires it.
if ((extractVersion >= ZipConstants.VersionZip64) &&
(((uint)size == uint.MaxValue) || ((uint)compressedSize == uint.MaxValue)))
{
}
}
if ( testData ) {
if ( entry.IsFile ) {
if ( !entry.IsCompressionMethodSupported() ) {
}
if ( (extractVersion > ZipConstants.VersionMadeBy)
|| ((extractVersion > 20) && (extractVersion < ZipConstants.VersionZip64)) ) {
}
if ( (localFlags & ( int )(GeneralBitFlags.Patched | GeneralBitFlags.StrongEncryption | GeneralBitFlags.EnhancedCompress | GeneralBitFlags.HeaderMasked)) != 0 ) {
}
}
}
if (testHeader)
{
// Name data has already been read convert it and compare.
string localName = ZipConstants.ConvertToStringExt(localFlags, nameData);
// Directories have zero actual size but can have compressed size
if (entry.IsDirectory)
{
// There may be other cases where the compressed size can be greater than this?
// If so until details are known we will be strict.
if (entry.IsCrypted)
{
}
else if (compressedSize > 2)
{
}
}
}
// Tests that apply to both data and header.
// Size can be verified only if it is known in the local header.
// it will always be known in the central header.
int extraLength = storedNameLength + extraDataLength;
return offsetOfFirstEntry + entry.Offset + ZipConstants.LocalHeaderBaseSize + extraLength;
}
}
/// <summary>
/// Process extra data fields updating the entry based on the contents.
/// </summary>
/// <param name="localHeader">True if the extra data fields should be handled
/// for a local header, rather than for a central header.
/// </param>
internal void ProcessExtraData(bool localHeader)
{
ZipExtraData extraData = new ZipExtraData(this.extra);
if ( extraData.Find(0x0001) ) {
// Version required to extract is ignored here as some archivers dont set it correctly
// in theory it should be version 45 or higher
// The recorded size will change but remember that this is zip64.
forceZip64_ = true;
if ( localHeader || (size == uint.MaxValue) ) {
size = (ulong)extraData.ReadLong();
}
if ( localHeader || (compressedSize == uint.MaxValue) ) {
compressedSize = (ulong)extraData.ReadLong();
}
if ( !localHeader && (offset == uint.MaxValue) ) {
offset = extraData.ReadLong();
}
// Disk number on which file starts is ignored
}
if ( extraData.Find(10) ) {
// No room for any tags.
extraData.ReadInt(); // Reserved
while ( extraData.UnreadCount >= 4 ) {
int ntfsTag = extraData.ReadShort();
int ntfsLength = extraData.ReadShort();
if ( ntfsTag == 1 ) {
if ( ntfsLength >= 24 ) {
long lastModification = extraData.ReadLong();
long lastAccess = extraData.ReadLong();
long createTime = extraData.ReadLong();
DateTime = System.DateTime.FromFileTime(lastModification);
}
break;
}
else {
// An unknown NTFS tag so simply skip it.
extraData.Skip(ntfsLength);
}
}
}
else if ( extraData.Find(0x5455) ) {
int length = extraData.ValueLength;
int flags = extraData.ReadByte();
// Can include other times but these are ignored. Length of data should
// actually be 1 + 4 * no of bits in flags.
if ( ((flags & 1) != 0) && (length >= 5) ) {
int iTime = extraData.ReadInt();
DateTime = (new System.DateTime ( 1970, 1, 1, 0, 0, 0 ).ToUniversalTime() +
new TimeSpan ( 0, 0, 0, iTime, 0 )).ToLocalTime();
}
}
if (method == CompressionMethod.WinZipAES) {
ProcessAESExtraData(extraData);
}
}
