64bit datadescriptors

src/SharpCompress/Common/Zip/StreamingZipFilePart.cs

@@ -47,6 +47,9 @@ internal BinaryReader FixStreamedFileLocation(ref RewindableStream rewindableStr
                 {
                     _decompressionStream.Skip();
 
+                    // If we had TotalIn / TotalOut we could have used them
+                    Header.CompressedSize = _decompressionStream.Position;
+
                     if (_decompressionStream is DeflateStream deflateStream)
                     {
                         rewindableStream.Rewind(deflateStream.InputBuffer);
@@ -66,12 +69,26 @@ internal BinaryReader FixStreamedFileLocation(ref RewindableStream rewindableStr
                         br.ReadUInt32(); // CRC32
                         var compressed_size = br.ReadUInt32();
                         var uncompressed_size = br.ReadUInt32();
+                        var uncompressed_64bit = br.ReadInt64();
+
+                        long test_64bit = (long)uncompressed_size << 32 | (long)compressed_size;
+
+                        if( test_64bit == size && test_64bit == uncompressed_64bit )
+                        {
+                            Header.CompressedSize = test_64bit;
+                            Header.UncompressedSize = uncompressed_64bit;
+                            rewindableStream.Position -= 24;
+                            break;
+                        }
+
                         if (compressed_size == size && compressed_size == uncompressed_size )
                         {
-                            rewindableStream.Position -= 16;
+                            Header.CompressedSize = compressed_size;
+                            Header.UncompressedSize = uncompressed_size;
+                            rewindableStream.Position -= 24;
                             break;
                         }
-                        rewindableStream.Position -= 12;
+                        rewindableStream.Position -= 20;
                     }
                 }
 

src/SharpCompress/Common/Zip/StreamingZipHeaderFactory.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.IO;
 using SharpCompress.Common.Zip.Headers;
 using SharpCompress.IO;
@@ -28,6 +28,7 @@ internal IEnumerable<ZipHeader> ReadStreamHeader(Stream stream)
             {
                 ZipHeader? header;
                 BinaryReader reader = new BinaryReader(rewindableStream);
+                uint headerBytes = 0;
                 if (_lastEntryHeader != null &&
                     (FlagUtility.HasFlag(_lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor) || _lastEntryHeader.IsZip64))
                 {
@@ -39,15 +40,37 @@ internal IEnumerable<ZipHeader> ReadStreamHeader(Stream stream)
                         crc = reader.ReadUInt32();
                     }
                     _lastEntryHeader.Crc = crc;
-                    _lastEntryHeader.CompressedSize = reader.ReadUInt32();
-                    _lastEntryHeader.UncompressedSize = reader.ReadUInt32();
+
+                    // The DataDescriptor can be either 64bit or 32bit
+                    var compressed_size = reader.ReadUInt32();
+                    var uncompressed_size = reader.ReadUInt32();
+
+                    // Check if we have header or 64bit DataDescriptor
+                    headerBytes = reader.ReadUInt32();
+                    bool test_header = !(headerBytes == 0x04034b50 || headerBytes == 0x02014b50);
+
+                    long test_64bit = (long)uncompressed_size << 32 | (long)compressed_size;
+                    if ( test_64bit == _lastEntryHeader.CompressedSize && test_header )
+                    {
+                        _lastEntryHeader.UncompressedSize = (long)reader.ReadUInt32() << 32 | (long)headerBytes;
+                        headerBytes = reader.ReadUInt32();
+                    }
+                    else
+                    {
+                        _lastEntryHeader.UncompressedSize = uncompressed_size;
+                    }
+
                     if (pos.HasValue)
                     {
                         _lastEntryHeader.DataStartPosition = pos - _lastEntryHeader.CompressedSize;
                     }
                 }
+                else
+                {
+                    headerBytes = reader.ReadUInt32();
+                }
+
                 _lastEntryHeader = null;
-                uint headerBytes = reader.ReadUInt32();
                 header = ReadHeader(headerBytes, reader);
                 if (header is null)
                 {
@@ -86,4 +109,4 @@ internal IEnumerable<ZipHeader> ReadStreamHeader(Stream stream)
             }
         }
     }
-}
+}

tests/SharpCompress.Test/Zip/ZipReaderTests.cs

@@ -401,8 +401,6 @@ public void Issue_685()
             }
         }
 
-
-
         [Fact]
         public void Zip_Uncompressed_Skip_All()
         {
@@ -415,5 +413,26 @@ public void Zip_Uncompressed_Skip_All()
                 }
             }
         }
+
+        [Fact]
+        public void Zip_Uncompressed_64bit()
+        {
+            var zipPath = Path.Combine(TEST_ARCHIVES_PATH, "64bitstream.zip.7z");
+            using (var stream = File.Open(zipPath, FileMode.Open, FileAccess.Read))
+            {
+                var archive = Archives.ArchiveFactory.Open(stream);
+                var reader = archive.ExtractAllEntries();
+                reader.MoveToNextEntry();
+                var zipReader = ZipReader.Open(reader.OpenEntryStream());
+                var x = 0;
+                while (zipReader.MoveToNextEntry())
+                {
+                    x++;
+                }
+
+                Assert.Equal(4, x);
+            }
+        }
+
     }
 }