// For AES the method in the entry is 99, and the real compression method is in the extradata // private void ProcessAESExtraData(ZipExtraData extraData) { #if !NET_1_1 && !NETCF_2_0 if (extraData.Find(0x9901)) { // Set version and flag for Zipfile.CreateAndInitDecryptionStream versionToExtract = ZipConstants.VERSION_AES; // Ver 5.1 = AES see "Version" getter // Set StrongEncryption flag for ZipFile.CreateAndInitDecryptionStream Flags = Flags | (int)GeneralBitFlags.StrongEncryption; // // Unpack AES extra data field see http://www.winzip.com/aes_info.htm int length = extraData.ValueLength; // Data size currently 7 if (length < 7) { throw new ZipException("AES Extra Data Length " + length + " invalid."); } int ver = extraData.ReadShort(); // Version number (1=AE-1 2=AE-2) int vendorId = extraData.ReadShort(); // 2-character vendor ID 0x4541 = "AE" int encrStrength = extraData.ReadByte(); // encryption strength 1 = 128 2 = 192 3 = 256 int actualCompress = extraData.ReadShort(); // The actual compression method used to compress the file _aesVer = ver; _aesEncryptionStrength = encrStrength; method = (CompressionMethod)actualCompress; } else { throw new ZipException("AES Extra Data missing"); } #else throw new ZipException("AES unsupported"); #endif }
void WriteLocalEntryHeader(ZipUpdate update) { ZipEntry entry = update.OutEntry; // TODO: Local offset will require adjusting for multi-disk zip files. entry.Offset = baseStream_.Position; // TODO: Need to clear any entry flags that dont make sense or throw an exception here. if (update.Command != UpdateCommand.Copy) { if (entry.CompressionMethod == CompressionMethod.Deflated) { if (entry.Size == 0) { // No need to compress - no data. entry.CompressedSize = entry.Size; entry.Crc = 0; entry.CompressionMethod = CompressionMethod.Stored; } } else if (entry.CompressionMethod == CompressionMethod.Stored) { entry.Flags &= ~(int)GeneralBitFlags.Descriptor; } if (HaveKeys) { entry.IsCrypted = true; if (entry.Crc < 0) { entry.Flags |= (int)GeneralBitFlags.Descriptor; } } else { entry.IsCrypted = false; } switch (useZip64_) { case UseZip64.Dynamic: if (entry.Size < 0) { entry.ForceZip64(); } break; case UseZip64.On: entry.ForceZip64(); break; case UseZip64.Off: // Do nothing. The entry itself may be using Zip64 independantly. break; } } // Write the local file header WriteLEInt(ZipConstants.LocalHeaderSignature); WriteLEShort(entry.Version); WriteLEShort(entry.Flags); WriteLEShort((byte)entry.CompressionMethod); WriteLEInt(( int )entry.DosTime); if ( !entry.HasCrc ) { // Note patch address for updating CRC later. update.CrcPatchOffset = baseStream_.Position; WriteLEInt(( int )0); } else { WriteLEInt(unchecked(( int )entry.Crc)); } if (entry.LocalHeaderRequiresZip64) { WriteLEInt(-1); WriteLEInt(-1); } else { if ( (entry.CompressedSize < 0) || (entry.Size < 0) ) { update.SizePatchOffset = baseStream_.Position; } WriteLEInt(( int )entry.CompressedSize); WriteLEInt(( int )entry.Size); } byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name); if ( name.Length > 0xFFFF ) { throw new ZipException("Entry name too long."); } ZipExtraData ed = new ZipExtraData(entry.ExtraData); if ( entry.LocalHeaderRequiresZip64 ) { ed.StartNewEntry(); // Local entry header always includes size and compressed size. // NOTE the order of these fields is reversed when compared to the normal headers! ed.AddLeLong(entry.Size); ed.AddLeLong(entry.CompressedSize); ed.AddNewEntry(1); } else { ed.Delete(1); } entry.ExtraData = ed.GetEntryData(); WriteLEShort(name.Length); WriteLEShort(entry.ExtraData.Length); if ( name.Length > 0 ) { baseStream_.Write(name, 0, name.Length); } if ( entry.LocalHeaderRequiresZip64 ) { if ( !ed.Find(1) ) { throw new ZipException("Internal error cannot find extra data"); } update.SizePatchOffset = baseStream_.Position + ed.CurrentReadIndex; } if ( entry.ExtraData.Length > 0 ) { baseStream_.Write(entry.ExtraData, 0, entry.ExtraData.Length); } }
/// <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) { throw new ZipException(string.Format("Wrong local header signature @{0:X}", offsetOfFirstEntry + entry.Offset)); } 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)) { throw new ZipException("Size invalid for descriptor"); } if ((compressedSize != -1) && (compressedSize != entry.CompressedSize)) { throw new ZipException("Compressed size invalid for descriptor"); } } } else { // No zip64 extra data but entry requires it. if ((extractVersion >= ZipConstants.VersionZip64) && (((uint)size == uint.MaxValue) || ((uint)compressedSize == uint.MaxValue))) { throw new ZipException("Required Zip64 extended information missing"); } } if ( testData ) { if ( entry.IsFile ) { if ( !entry.IsCompressionMethodSupported() ) { throw new ZipException("Compression method not supported"); } if ( (extractVersion > ZipConstants.VersionMadeBy) || ((extractVersion > 20) && (extractVersion < ZipConstants.VersionZip64)) ) { throw new ZipException(string.Format("Version required to extract this entry not supported ({0})", extractVersion)); } if ( (localFlags & ( int )(GeneralBitFlags.Patched | GeneralBitFlags.StrongEncryption | GeneralBitFlags.EnhancedCompress | GeneralBitFlags.HeaderMasked)) != 0 ) { throw new ZipException("The library does not support the zip version required to extract this entry"); } } } if (testHeader) { if ((extractVersion <= 63) && // Ignore later versions as we dont know about them.. (extractVersion != 10) && (extractVersion != 11) && (extractVersion != 20) && (extractVersion != 21) && (extractVersion != 25) && (extractVersion != 27) && (extractVersion != 45) && (extractVersion != 46) && (extractVersion != 50) && (extractVersion != 51) && (extractVersion != 52) && (extractVersion != 61) && (extractVersion != 62) && (extractVersion != 63) ) { throw new ZipException(string.Format("Version required to extract this entry is invalid ({0})", extractVersion)); } // Local entry flags dont have reserved bit set on. if ((localFlags & (int)(GeneralBitFlags.ReservedPKware4 | GeneralBitFlags.ReservedPkware14 | GeneralBitFlags.ReservedPkware15)) != 0) { throw new ZipException("Reserved bit flags cannot be set."); } // Encryption requires extract version >= 20 if (((localFlags & (int)GeneralBitFlags.Encrypted) != 0) && (extractVersion < 20)) { throw new ZipException(string.Format("Version required to extract this entry is too low for encryption ({0})", extractVersion)); } // Strong encryption requires encryption flag to be set and extract version >= 50. if ((localFlags & (int)GeneralBitFlags.StrongEncryption) != 0) { if ((localFlags & (int)GeneralBitFlags.Encrypted) == 0) { throw new ZipException("Strong encryption flag set but encryption flag is not set"); } if (extractVersion < 50) { throw new ZipException(string.Format("Version required to extract this entry is too low for encryption ({0})", extractVersion)); } } // Patched entries require extract version >= 27 if (((localFlags & (int)GeneralBitFlags.Patched) != 0) && (extractVersion < 27)) { throw new ZipException(string.Format("Patched data requires higher version than ({0})", extractVersion)); } // Central header flags match local entry flags. if (localFlags != entry.Flags) { throw new ZipException("Central header/local header flags mismatch"); } // Central header compression method matches local entry if (entry.CompressionMethod != (CompressionMethod)compressionMethod) { throw new ZipException("Central header/local header compression method mismatch"); } if (entry.Version != extractVersion) { throw new ZipException("Extract version mismatch"); } // Strong encryption and extract version match if ((localFlags & (int)GeneralBitFlags.StrongEncryption) != 0) { if (extractVersion < 62) { throw new ZipException("Strong encryption flag set but version not high enough"); } } if ((localFlags & (int)GeneralBitFlags.HeaderMasked) != 0) { if ((fileTime != 0) || (fileDate != 0)) { throw new ZipException("Header masked set but date/time values non-zero"); } } if ((localFlags & (int)GeneralBitFlags.Descriptor) == 0) { if (crcValue != (uint)entry.Crc) { throw new ZipException("Central header/local header crc mismatch"); } } // Crc valid for empty entry. // This will also apply to streamed entries where size isnt known and the header cant be patched if ((size == 0) && (compressedSize == 0)) { if (crcValue != 0) { throw new ZipException("Invalid CRC for empty entry"); } } // TODO: make test more correct... can't compare lengths as was done originally as this can fail for MBCS strings // Assuming a code page at this point is not valid? Best is to store the name length in the ZipEntry probably if (entry.Name.Length > storedNameLength) { throw new ZipException("File name length mismatch"); } // Name data has already been read convert it and compare. string localName = ZipConstants.ConvertToStringExt(localFlags, nameData); // Central directory and local entry name match if (localName != entry.Name) { throw new ZipException("Central header and local header file name mismatch"); } // Directories have zero actual size but can have compressed size if (entry.IsDirectory) { if (size > 0) { throw new ZipException("Directory cannot have size"); } // 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) { if (compressedSize > ZipConstants.CryptoHeaderSize + 2) { throw new ZipException("Directory compressed size invalid"); } } else if (compressedSize > 2) { // When not compressed the directory size can validly be 2 bytes // if the true size wasnt known when data was originally being written. // NOTE: Versions of the library 0.85.4 and earlier always added 2 bytes throw new ZipException("Directory compressed size invalid"); } } if (!ZipNameTransform.IsValidName(localName, true)) { throw new ZipException("Name is invalid"); } } // 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. if (((localFlags & (int)GeneralBitFlags.Descriptor) == 0) || ((size > 0) || (compressedSize > 0))) { if (size != entry.Size) { throw new ZipException( string.Format("Size mismatch between central header({0}) and local header({1})", entry.Size, size)); } if (compressedSize != entry.CompressedSize && compressedSize != 0xFFFFFFFF && compressedSize != -1) { throw new ZipException( string.Format("Compressed size mismatch between central header({0}) and local header({1})", entry.CompressedSize, compressedSize)); } } 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 (extraData.ValueLength < 4) { throw new ZipException("Extra data extended Zip64 information length is invalid"); } 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 } else { if ( ((versionToExtract & 0xff) >= ZipConstants.VersionZip64) && ((size == uint.MaxValue) || (compressedSize == uint.MaxValue)) ) { throw new ZipException("Zip64 Extended information required but is missing."); } } if (extraData.Find(10)) { // No room for any tags. if (extraData.ValueLength < 4) { throw new ZipException("NTFS Extra data invalid"); } 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); } }
// Write the local file header // TODO: ZipHelperStream.WriteLocalHeader is not yet used and needs checking for ZipFile and ZipOuptutStream usage void WriteLocalHeader(ZipEntry entry, EntryPatchData patchData) { CompressionMethod method = entry.CompressionMethod; bool headerInfoAvailable = true; // How to get this? bool patchEntryHeader = false; WriteLEInt(ZipConstants.LocalHeaderSignature); WriteLEShort(entry.Version); WriteLEShort(entry.Flags); WriteLEShort((byte)method); WriteLEInt((int)entry.DosTime); if (headerInfoAvailable == true) { WriteLEInt((int)entry.Crc); if (entry.LocalHeaderRequiresZip64) { WriteLEInt(-1); WriteLEInt(-1); } else { WriteLEInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize); WriteLEInt((int)entry.Size); } } else { if (patchData != null) { patchData.CrcPatchOffset = stream_.Position; } WriteLEInt(0); // Crc if (patchData != null) { patchData.SizePatchOffset = stream_.Position; } // For local header both sizes appear in Zip64 Extended Information if (entry.LocalHeaderRequiresZip64 && patchEntryHeader) { WriteLEInt(-1); WriteLEInt(-1); } else { WriteLEInt(0); // Compressed size WriteLEInt(0); // Uncompressed size } } byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name); if (name.Length > 0xFFFF) { throw new ZipException("Entry name too long."); } ZipExtraData ed = new ZipExtraData(entry.ExtraData); if (entry.LocalHeaderRequiresZip64 && (headerInfoAvailable || patchEntryHeader)) { ed.StartNewEntry(); if (headerInfoAvailable) { ed.AddLeLong(entry.Size); ed.AddLeLong(entry.CompressedSize); } else { ed.AddLeLong(-1); ed.AddLeLong(-1); } ed.AddNewEntry(1); if (!ed.Find(1)) { throw new ZipException("Internal error cant find extra data"); } if (patchData != null) { patchData.SizePatchOffset = ed.CurrentReadIndex; } } else { ed.Delete(1); } byte[] extra = ed.GetEntryData(); WriteLEShort(name.Length); WriteLEShort(extra.Length); if (name.Length > 0) { stream_.Write(name, 0, name.Length); } if (entry.LocalHeaderRequiresZip64 && patchEntryHeader) { patchData.SizePatchOffset += stream_.Position; } if (extra.Length > 0) { stream_.Write(extra, 0, extra.Length); } }
/// <summary> /// Starts a new Zip entry. It automatically closes the previous /// entry if present. /// All entry elements bar name are optional, but must be correct if present. /// If the compression method is stored and the output is not patchable /// the compression for that entry is automatically changed to deflate level 0 /// </summary> /// <param name="entry"> /// the entry. /// </param> /// <exception cref="System.ArgumentNullException"> /// if entry passed is null. /// </exception> /// <exception cref="System.IO.IOException"> /// if an I/O error occured. /// </exception> /// <exception cref="System.InvalidOperationException"> /// if stream was finished /// </exception> /// <exception cref="ZipException"> /// Too many entries in the Zip file<br/> /// Entry name is too long<br/> /// Finish has already been called<br/> /// </exception> public void PutNextEntry(ZipEntry entry) { if ( entry == null ) { throw new ArgumentNullException("entry"); } if (entries == null) { throw new InvalidOperationException("ZipOutputStream was finished"); } if (curEntry != null) { CloseEntry(); } if (entries.Count == int.MaxValue) { throw new ZipException("Too many entries for Zip file"); } CompressionMethod method = entry.CompressionMethod; int compressionLevel = defaultCompressionLevel; // Clear flags that the library manages internally entry.Flags &= (int)GeneralBitFlags.UnicodeText; patchEntryHeader = false; bool headerInfoAvailable; // No need to compress - definitely no data. if (entry.Size == 0) { entry.CompressedSize = entry.Size; entry.Crc = 0; method = CompressionMethod.Stored; headerInfoAvailable = true; } else { headerInfoAvailable = (entry.Size >= 0) && entry.HasCrc; // Switch to deflation if storing isnt possible. if (method == CompressionMethod.Stored) { if (!headerInfoAvailable) { if (!CanPatchEntries) { // Can't patch entries so storing is not possible. method = CompressionMethod.Deflated; compressionLevel = 0; } } else // entry.size must be > 0 { entry.CompressedSize = entry.Size; headerInfoAvailable = entry.HasCrc; } } } if (headerInfoAvailable == false) { if (CanPatchEntries == false) { // Only way to record size and compressed size is to append a data descriptor // after compressed data. // Stored entries of this form have already been converted to deflating. entry.Flags |= 8; } else { patchEntryHeader = true; } } if (Password != null) { entry.IsCrypted = true; if (entry.Crc < 0) { // Need to append a data descriptor as the crc isnt available for use // with encryption, the date is used instead. Setting the flag // indicates this to the decompressor. entry.Flags |= 8; } } entry.Offset = offset; entry.CompressionMethod = (CompressionMethod)method; curMethod = method; sizePatchPos = -1; if ( (useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic)) ) { entry.ForceZip64(); } // Write the local file header WriteLeInt(ZipConstants.LocalHeaderSignature); WriteLeShort(entry.Version); WriteLeShort(entry.Flags); WriteLeShort((byte)entry.CompressionMethodForHeader); WriteLeInt((int)entry.DosTime); // TODO: Refactor header writing. Its done in several places. if (headerInfoAvailable == true) { WriteLeInt((int)entry.Crc); if ( entry.LocalHeaderRequiresZip64 ) { WriteLeInt(-1); WriteLeInt(-1); } else { WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize); WriteLeInt((int)entry.Size); } } else { if (patchEntryHeader) { crcPatchPos = baseOutputStream_.Position; } WriteLeInt(0); // Crc if ( patchEntryHeader ) { sizePatchPos = baseOutputStream_.Position; } // For local header both sizes appear in Zip64 Extended Information if ( entry.LocalHeaderRequiresZip64 || patchEntryHeader ) { WriteLeInt(-1); WriteLeInt(-1); } else { WriteLeInt(0); // Compressed size WriteLeInt(0); // Uncompressed size } } byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name); if (name.Length > 0xFFFF) { throw new ZipException("Entry name too long."); } ZipExtraData ed = new ZipExtraData(entry.ExtraData); if (entry.LocalHeaderRequiresZip64) { ed.StartNewEntry(); if (headerInfoAvailable) { ed.AddLeLong(entry.Size); ed.AddLeLong(entry.CompressedSize); } else { ed.AddLeLong(-1); ed.AddLeLong(-1); } ed.AddNewEntry(1); if ( !ed.Find(1) ) { throw new ZipException("Internal error cant find extra data"); } if ( patchEntryHeader ) { sizePatchPos = ed.CurrentReadIndex; } } else { ed.Delete(1); } #if !NET_1_1 && !NETCF_2_0 if (entry.AESKeySize > 0) { AddExtraDataAES(entry, ed); } #endif byte[] extra = ed.GetEntryData(); WriteLeShort(name.Length); WriteLeShort(extra.Length); if ( name.Length > 0 ) { baseOutputStream_.Write(name, 0, name.Length); } if ( entry.LocalHeaderRequiresZip64 && patchEntryHeader ) { sizePatchPos += baseOutputStream_.Position; } if ( extra.Length > 0 ) { baseOutputStream_.Write(extra, 0, extra.Length); } offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length; // Fix offsetOfCentraldir for AES if (entry.AESKeySize > 0) offset += entry.AESOverheadSize; // Activate the entry. curEntry = entry; crc.Reset(); if (method == CompressionMethod.Deflated) { deflater_.Reset(); deflater_.SetLevel(compressionLevel); } size = 0; if (entry.IsCrypted) { #if !NET_1_1 && !NETCF_2_0 if (entry.AESKeySize > 0) { WriteAESHeader(entry); } else #endif { if (entry.Crc < 0) { // so testing Zip will says its ok WriteEncryptionHeader(entry.DosTime << 16); } else { WriteEncryptionHeader(entry.Crc); } } } }
/// <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 ( extraData.ValueLength < 4 ) { throw new ZipException("Extra data extended Zip64 information length is invalid"); } 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 } else { if ( ((versionToExtract & 0xff) >= ZipConstants.VersionZip64) && ((size == uint.MaxValue) || (compressedSize == uint.MaxValue)) ) { throw new ZipException("Zip64 Extended information required but is missing."); } } if ( extraData.Find(10) ) { // No room for any tags. if ( extraData.ValueLength < 4 ) { throw new ZipException("NTFS Extra data invalid"); } 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); } }
// For AES the method in the entry is 99, and the real compression method is in the extradata // private void ProcessAESExtraData(ZipExtraData extraData) { #if !NET_1_1 && !NETCF_2_0 if (extraData.Find(0x9901)) { // Set version and flag for Zipfile.CreateAndInitDecryptionStream versionToExtract = ZipConstants.VERSION_AES; // Ver 5.1 = AES see "Version" getter // Set StrongEncryption flag for ZipFile.CreateAndInitDecryptionStream Flags = Flags | (int)GeneralBitFlags.StrongEncryption; // // Unpack AES extra data field see http://www.winzip.com/aes_info.htm int length = extraData.ValueLength; // Data size currently 7 if (length < 7) throw new ZipException("AES Extra Data Length " + length + " invalid."); int ver = extraData.ReadShort(); // Version number (1=AE-1 2=AE-2) int vendorId = extraData.ReadShort(); // 2-character vendor ID 0x4541 = "AE" int encrStrength = extraData.ReadByte(); // encryption strength 1 = 128 2 = 192 3 = 256 int actualCompress = extraData.ReadShort(); // The actual compression method used to compress the file _aesVer = ver; _aesEncryptionStrength = encrStrength; method = (CompressionMethod)actualCompress; } else throw new ZipException("AES Extra Data missing"); #else throw new ZipException("AES unsupported"); #endif }
/// <summary> /// Starts a new Zip entry. It automatically closes the previous /// entry if present. /// All entry elements bar name are optional, but must be correct if present. /// If the compression method is stored and the output is not patchable /// the compression for that entry is automatically changed to deflate level 0 /// </summary> /// <param name="entry"> /// the entry. /// </param> /// <exception cref="System.ArgumentNullException"> /// if entry passed is null. /// </exception> /// <exception cref="System.IO.IOException"> /// if an I/O error occured. /// </exception> /// <exception cref="System.InvalidOperationException"> /// if stream was finished /// </exception> /// <exception cref="ZipException"> /// Too many entries in the Zip file<br/> /// Entry name is too long<br/> /// Finish has already been called<br/> /// </exception> public void PutNextEntry(ZipEntry entry) { if (entry == null) { throw new ArgumentNullException("entry"); } if (entries == null) { throw new InvalidOperationException("ZipOutputStream was finished"); } if (curEntry != null) { CloseEntry(); } if (entries.Count == int.MaxValue) { throw new ZipException("Too many entries for Zip file"); } CompressionMethod method = entry.CompressionMethod; int compressionLevel = defaultCompressionLevel; // Clear flags that the library manages internally entry.Flags &= (int)GeneralBitFlags.UnicodeText; patchEntryHeader = false; bool headerInfoAvailable; // No need to compress - definitely no data. if (entry.Size == 0) { entry.CompressedSize = entry.Size; entry.Crc = 0; method = CompressionMethod.Stored; headerInfoAvailable = true; } else { headerInfoAvailable = (entry.Size >= 0) && entry.HasCrc; // Switch to deflation if storing isnt possible. if (method == CompressionMethod.Stored) { if (!headerInfoAvailable) { if (!CanPatchEntries) { // Can't patch entries so storing is not possible. method = CompressionMethod.Deflated; compressionLevel = 0; } } else // entry.size must be > 0 { entry.CompressedSize = entry.Size; headerInfoAvailable = entry.HasCrc; } } } if (headerInfoAvailable == false) { if (CanPatchEntries == false) { // Only way to record size and compressed size is to append a data descriptor // after compressed data. // Stored entries of this form have already been converted to deflating. entry.Flags |= 8; } else { patchEntryHeader = true; } } if (Password != null) { entry.IsCrypted = true; if (entry.Crc < 0) { // Need to append a data descriptor as the crc isnt available for use // with encryption, the date is used instead. Setting the flag // indicates this to the decompressor. entry.Flags |= 8; } } entry.Offset = offset; entry.CompressionMethod = (CompressionMethod)method; curMethod = method; sizePatchPos = -1; if ((useZip64_ == UseZip64.On) || ((entry.Size < 0) && (useZip64_ == UseZip64.Dynamic))) { entry.ForceZip64(); } // Write the local file header WriteLeInt(ZipConstants.LocalHeaderSignature); WriteLeShort(entry.Version); WriteLeShort(entry.Flags); WriteLeShort((byte)entry.CompressionMethodForHeader); WriteLeInt((int)entry.DosTime); // TODO: Refactor header writing. Its done in several places. if (headerInfoAvailable == true) { WriteLeInt((int)entry.Crc); if (entry.LocalHeaderRequiresZip64) { WriteLeInt(-1); WriteLeInt(-1); } else { WriteLeInt(entry.IsCrypted ? (int)entry.CompressedSize + ZipConstants.CryptoHeaderSize : (int)entry.CompressedSize); WriteLeInt((int)entry.Size); } } else { if (patchEntryHeader) { crcPatchPos = baseOutputStream_.Position; } WriteLeInt(0); // Crc if (patchEntryHeader) { sizePatchPos = baseOutputStream_.Position; } // For local header both sizes appear in Zip64 Extended Information if (entry.LocalHeaderRequiresZip64 || patchEntryHeader) { WriteLeInt(-1); WriteLeInt(-1); } else { WriteLeInt(0); // Compressed size WriteLeInt(0); // Uncompressed size } } byte[] name = ZipConstants.ConvertToArray(entry.Flags, entry.Name); if (name.Length > 0xFFFF) { throw new ZipException("Entry name too long."); } ZipExtraData ed = new ZipExtraData(entry.ExtraData); if (entry.LocalHeaderRequiresZip64) { ed.StartNewEntry(); if (headerInfoAvailable) { ed.AddLeLong(entry.Size); ed.AddLeLong(entry.CompressedSize); } else { ed.AddLeLong(-1); ed.AddLeLong(-1); } ed.AddNewEntry(1); if (!ed.Find(1)) { throw new ZipException("Internal error cant find extra data"); } if (patchEntryHeader) { sizePatchPos = ed.CurrentReadIndex; } } else { ed.Delete(1); } #if !NET_1_1 && !NETCF_2_0 if (entry.AESKeySize > 0) { AddExtraDataAES(entry, ed); } #endif byte[] extra = ed.GetEntryData(); WriteLeShort(name.Length); WriteLeShort(extra.Length); if (name.Length > 0) { baseOutputStream_.Write(name, 0, name.Length); } if (entry.LocalHeaderRequiresZip64 && patchEntryHeader) { sizePatchPos += baseOutputStream_.Position; } if (extra.Length > 0) { baseOutputStream_.Write(extra, 0, extra.Length); } offset += ZipConstants.LocalHeaderBaseSize + name.Length + extra.Length; // Fix offsetOfCentraldir for AES if (entry.AESKeySize > 0) { offset += entry.AESOverheadSize; } // Activate the entry. curEntry = entry; crc.Reset(); if (method == CompressionMethod.Deflated) { deflater_.Reset(); deflater_.SetLevel(compressionLevel); } size = 0; if (entry.IsCrypted) { #if !NET_1_1 && !NETCF_2_0 if (entry.AESKeySize > 0) { WriteAESHeader(entry); } else #endif { if (entry.Crc < 0) // so testing Zip will says its ok { WriteEncryptionHeader(entry.DosTime << 16); } else { WriteEncryptionHeader(entry.Crc); } } } }