From cd3cbd2b3272f002693aad84a79da145604e9618 Mon Sep 17 00:00:00 2001
From: Kenneth Skovhede <kenneth@hexad.dk>
Date: Thu, 9 Mar 2017 23:18:57 +0100
Subject: [PATCH] Support for writing zip64 headers in the unused code

---
 .../Zip/Headers/DirectoryEntryHeader.cs       | 32 +++++++++++++----
 .../Common/Zip/Headers/LocalEntryHeader.cs    | 35 ++++++++++++++++---
 2 files changed, 57 insertions(+), 10 deletions(-)

diff --git a/src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs b/src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs
index 3b50d118..b7d3d5c7 100644
--- a/src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs
+++ b/src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs
@@ -63,6 +63,10 @@ namespace SharpCompress.Common.Zip.Headers
 
         internal override void Write(BinaryWriter writer)
         {
+			var zip64 = CompressedSize >= uint.MaxValue || UncompressedSize >= uint.MaxValue || RelativeOffsetOfEntryHeader >= uint.MaxValue;
+			if (zip64)
+				Version = (ushort)(Version > 45 ? Version : 45);
+
             writer.Write(Version);
             writer.Write(VersionNeededToExtract);
             writer.Write((ushort)Flags);
@@ -70,24 +74,40 @@ namespace SharpCompress.Common.Zip.Headers
             writer.Write(LastModifiedTime);
             writer.Write(LastModifiedDate);
             writer.Write(Crc);
-            writer.Write((uint)CompressedSize);
-            writer.Write((uint)UncompressedSize);
+			writer.Write(zip64 ? uint.MaxValue : CompressedSize);
+            writer.Write(zip64 ? uint.MaxValue : UncompressedSize);
 
             byte[] nameBytes = EncodeString(Name);
             writer.Write((ushort)nameBytes.Length);
 
-            //writer.Write((ushort)Extra.Length);
-            writer.Write((ushort)0);
+			if (zip64)
+			{
+				writer.Write((ushort)(2 + 2 + 8 + 8 + 8 + 4));
+			}
+			else
+			{
+				//writer.Write((ushort)Extra.Length);
+				writer.Write((ushort)0);
+			}
             writer.Write((ushort)Comment.Length);
 
             writer.Write(DiskNumberStart);
             writer.Write(InternalFileAttributes);
             writer.Write(ExternalFileAttributes);
-            writer.Write(RelativeOffsetOfEntryHeader);
+            writer.Write(zip64 ? uint.MaxValue : RelativeOffsetOfEntryHeader);
 
             writer.Write(nameBytes);
 
-            // writer.Write(Extra);
+			if (zip64)
+			{
+				writer.Write((ushort)0x0001);
+				writer.Write((ushort)((8 + 8 + 8 + 4)));
+
+				writer.Write((ulong)UncompressedSize);
+				writer.Write((ulong)CompressedSize);
+				writer.Write((ulong)RelativeOffsetOfEntryHeader);
+				writer.Write((uint)0); // VolumeNumber = 0
+			}
             writer.Write(Comment);
         }
 
diff --git a/src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs b/src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs
index 2e311cc8..fe539406 100644
--- a/src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs
+++ b/src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs
@@ -49,25 +49,52 @@ namespace SharpCompress.Common.Zip.Headers
 
         internal override void Write(BinaryWriter writer)
         {
-            writer.Write(Version);
+			if (IsZip64)
+				Version = (ushort)(Version > 45 ? Version : 45);
+
+			writer.Write(Version);
+			
             writer.Write((ushort)Flags);
             writer.Write((ushort)CompressionMethod);
             writer.Write(LastModifiedTime);
             writer.Write(LastModifiedDate);
             writer.Write(Crc);
-            writer.Write((uint)CompressedSize);
-            writer.Write((uint)UncompressedSize);
+
+			if (IsZip64)
+			{
+				writer.Write(uint.MaxValue);
+				writer.Write(uint.MaxValue);
+			}
+			else
+			{
+				writer.Write(CompressedSize);
+				writer.Write(UncompressedSize);
+			}
 
             byte[] nameBytes = EncodeString(Name);
 
             writer.Write((ushort)nameBytes.Length);
-            writer.Write((ushort)0);
+			if (IsZip64)
+			{
+				writer.Write((ushort)(2 + 2 + (2 * 8)));
+			}
+			else
+			{
+				writer.Write((ushort)0);
+			}
 
             //if (Extra != null)
             //{
             //    writer.Write(Extra);
             //}
             writer.Write(nameBytes);
+			if (IsZip64)
+			{
+				writer.Write((ushort)0x0001);
+				writer.Write((ushort)(2 * 8));
+				writer.Write((ulong)CompressedSize);
+				writer.Write((ulong)UncompressedSize);
+			}
         }
 
         internal ushort Version { get; private set; }