Handle raw deflate response from some servers

Author: scott-xu

src/Renci.SshNet/Compression/Zlib.cs

@@ -1,6 +1,10 @@
 #if NET6_0_OR_GREATER
+using System.Diagnostics;
+using System;
 using System.IO;
 using System.IO.Compression;
+using System.Threading.Tasks;
+using System.Threading;
 
 namespace Renci.SshNet.Compression
 {
@@ -28,20 +32,24 @@ public override string Name
         protected override byte[] CompressCore(byte[] data, int offset, int length)
         {
             using var outputStream = new MemoryStream();
-            using var zlibStream = new ZLibStream(outputStream, CompressionMode.Compress);
+            using var stream = new ZLibStream(outputStream, CompressionMode.Compress);
 
-            zlibStream.Write(data, offset, length);
+            stream.Write(data, offset, length);
 
             return outputStream.ToArray();
         }
 
         protected override byte[] DecompressCore(byte[] data, int offset, int length)
         {
             using var inputStream = new MemoryStream(data, offset, length);
-            using var zlibStream = new ZLibStream(inputStream, CompressionMode.Decompress);
+
+            // Handle raw deflate response from some servers
+            using Stream stream = (data[offset] & 0xF) == 8 ?
+                new ZLibStream(inputStream, CompressionMode.Decompress) :
+                new DeflateStream(inputStream, CompressionMode.Decompress);
 
             using var outputStream = new MemoryStream();
-            zlibStream.CopyTo(outputStream);
+            stream.CopyTo(outputStream);
 
             return outputStream.ToArray();
         }