Use platform compression where available

- Move Bzip2 code into Utilities

14 files changed, 203 insertions, 81 deletions

diff --git a/crypto/src/cms/CMSCompressedData.cs b/crypto/src/cms/CMSCompressedData.cs
index 21651f041..5f8165005 100644
--- a/crypto/src/cms/CMSCompressedData.cs
+++ b/crypto/src/cms/CMSCompressedData.cs
@@ -1,10 +1,9 @@
-using System;
 using System.IO;
 
 using Org.BouncyCastle.Asn1;
 using Org.BouncyCastle.Asn1.Cms;
 using Org.BouncyCastle.Utilities;
-using Org.BouncyCastle.Utilities.Zlib;
+using Org.BouncyCastle.Utilities.IO.Compression;
 
 namespace Org.BouncyCastle.Cms
 {
@@ -45,7 +44,7 @@ namespace Org.BouncyCastle.Cms
             ContentInfo content = comData.EncapContentInfo;
 
 			Asn1OctetString bytes = (Asn1OctetString) content.Content;
-			ZInputStream zIn = new ZInputStream(bytes.GetOctetStream());
+			Stream zIn = ZLib.DecompressInput(bytes.GetOctetStream());
 
 			try
 			{
@@ -76,8 +75,7 @@ namespace Org.BouncyCastle.Cms
 			ContentInfo     content = comData.EncapContentInfo;
 
 			Asn1OctetString bytes = (Asn1OctetString)content.Content;
-
-			ZInputStream zIn = new ZInputStream(new MemoryStream(bytes.GetOctets(), false));
+            Stream zIn = ZLib.DecompressInput(bytes.GetOctetStream());
 
 			try
 			{
diff --git a/crypto/src/cms/CMSCompressedDataGenerator.cs b/crypto/src/cms/CMSCompressedDataGenerator.cs
index bea04752a..872c4a144 100644
--- a/crypto/src/cms/CMSCompressedDataGenerator.cs
+++ b/crypto/src/cms/CMSCompressedDataGenerator.cs
@@ -5,7 +5,6 @@ using Org.BouncyCastle.Asn1;
 using Org.BouncyCastle.Asn1.Cms;
 using Org.BouncyCastle.Asn1.X509;
 using Org.BouncyCastle.Utilities;
-using Org.BouncyCastle.Utilities.Zlib;
 
 namespace Org.BouncyCastle.Cms
 {
@@ -22,9 +21,12 @@ namespace Org.BouncyCastle.Cms
     */
     public class CmsCompressedDataGenerator
     {
-        public const string ZLib = "1.2.840.113549.1.9.16.3.8";
+        public const string ZLibOid = "1.2.840.113549.1.9.16.3.8";
 
-		public CmsCompressedDataGenerator()
+        [Obsolete("Use 'ZLibOid' instead")]
+        public const string ZLib = ZLibOid;
+
+        public CmsCompressedDataGenerator()
         {
         }
 
@@ -41,7 +43,7 @@ namespace Org.BouncyCastle.Cms
             try
             {
                 MemoryStream bOut = new MemoryStream();
-                ZOutputStream zOut = new ZOutputStream(bOut, JZlib.Z_DEFAULT_COMPRESSION);
+                Stream zOut = Utilities.IO.Compression.ZLib.CompressOutput(bOut, -1);
 
 				content.Write(zOut);
 
diff --git a/crypto/src/cms/CMSCompressedDataParser.cs b/crypto/src/cms/CMSCompressedDataParser.cs
index b107ff608..38ff88968 100644
--- a/crypto/src/cms/CMSCompressedDataParser.cs
+++ b/crypto/src/cms/CMSCompressedDataParser.cs
@@ -3,7 +3,7 @@ using System.IO;
 
 using Org.BouncyCastle.Asn1;
 using Org.BouncyCastle.Asn1.Cms;
-using Org.BouncyCastle.Utilities.Zlib;
+using Org.BouncyCastle.Utilities.IO.Compression;
 
 namespace Org.BouncyCastle.Cms
 {
@@ -44,8 +44,9 @@ namespace Org.BouncyCastle.Cms
                 ContentInfoParser content = comData.GetEncapContentInfo();
 
                 Asn1OctetStringParser bytes = (Asn1OctetStringParser)content.GetContent(Asn1Tags.OctetString);
+                Stream zIn = ZLib.DecompressInput(bytes.GetOctetStream());
 
-                return new CmsTypedStream(content.ContentType.ToString(), new ZInputStream(bytes.GetOctetStream()));
+                return new CmsTypedStream(content.ContentType.ToString(), zIn);
             }
             catch (IOException e)
             {
diff --git a/crypto/src/cms/CMSCompressedDataStreamGenerator.cs b/crypto/src/cms/CMSCompressedDataStreamGenerator.cs
index 9a9c29b01..855367320 100644
--- a/crypto/src/cms/CMSCompressedDataStreamGenerator.cs
+++ b/crypto/src/cms/CMSCompressedDataStreamGenerator.cs
@@ -6,7 +6,6 @@ using Org.BouncyCastle.Asn1.Cms;
 using Org.BouncyCastle.Asn1.X509;
 using Org.BouncyCastle.Utilities;
 using Org.BouncyCastle.Utilities.IO;
-using Org.BouncyCastle.Utilities.Zlib;
 
 namespace Org.BouncyCastle.Cms
 {
@@ -27,7 +26,10 @@ namespace Org.BouncyCastle.Cms
 	*/
 	public class CmsCompressedDataStreamGenerator
 	{
-		public const string ZLib = "1.2.840.113549.1.9.16.3.8";
+        public const string ZLibOid = "1.2.840.113549.1.9.16.3.8";
+
+        [Obsolete("Use 'ZLibOid' instead")]
+        public const string ZLib = ZLibOid;
 
 		private int _bufferSize;
 		
@@ -88,19 +90,19 @@ namespace Org.BouncyCastle.Cms
 				eiGen.GetRawOutputStream(), 0, true, _bufferSize);
 
 			return new CmsCompressedOutputStream(
-				new ZOutputStream(octetStream, JZlib.Z_DEFAULT_COMPRESSION), sGen, cGen, eiGen);
+				Utilities.IO.Compression.ZLib.CompressOutput(octetStream, -1), sGen, cGen, eiGen);
 		}
 
 		private class CmsCompressedOutputStream
 			: BaseOutputStream
 		{
-			private ZOutputStream _out;
+			private Stream _out;
 			private BerSequenceGenerator _sGen;
 			private BerSequenceGenerator _cGen;
 			private BerSequenceGenerator _eiGen;
 
 			internal CmsCompressedOutputStream(
-				ZOutputStream			outStream,
+				Stream					outStream,
 				BerSequenceGenerator	sGen,
 				BerSequenceGenerator	cGen,
 				BerSequenceGenerator	eiGen)
diff --git a/crypto/src/openpgp/PgpCompressedData.cs b/crypto/src/openpgp/PgpCompressedData.cs
index fc7d200d0..346b0b1a1 100644
--- a/crypto/src/openpgp/PgpCompressedData.cs
+++ b/crypto/src/openpgp/PgpCompressedData.cs
@@ -1,7 +1,6 @@
 using System.IO;
 
-using Org.BouncyCastle.Bzip2;
-using Org.BouncyCastle.Utilities.Zlib;
+using Org.BouncyCastle.Utilities.IO.Compression;
 
 namespace Org.BouncyCastle.Bcpg.OpenPgp
 {
@@ -38,16 +37,16 @@ namespace Org.BouncyCastle.Bcpg.OpenPgp
         {
             switch (Algorithm)
             {
-				case CompressionAlgorithmTag.Uncompressed:
-					return GetInputStream();
-				case CompressionAlgorithmTag.Zip:
-					return new ZInputStream(GetInputStream(), true);
-                case CompressionAlgorithmTag.ZLib:
-					return new ZInputStream(GetInputStream());
-				case CompressionAlgorithmTag.BZip2:
-					return new CBZip2InputStream(GetInputStream());
-                default:
-                    throw new PgpException("can't recognise compression algorithm: " + Algorithm);
+			case CompressionAlgorithmTag.Uncompressed:
+				return GetInputStream();
+			case CompressionAlgorithmTag.Zip:
+                return Zip.DecompressInput(GetInputStream());
+            case CompressionAlgorithmTag.ZLib:
+				return ZLib.DecompressInput(GetInputStream());
+			case CompressionAlgorithmTag.BZip2:
+                return Bzip2.DecompressInput(GetInputStream());
+            default:
+                throw new PgpException("can't recognise compression algorithm: " + Algorithm);
             }
         }
     }
diff --git a/crypto/src/openpgp/PgpCompressedDataGenerator.cs b/crypto/src/openpgp/PgpCompressedDataGenerator.cs
index 791aac0bf..d13d7402b 100644
--- a/crypto/src/openpgp/PgpCompressedDataGenerator.cs
+++ b/crypto/src/openpgp/PgpCompressedDataGenerator.cs
@@ -1,8 +1,8 @@
 using System;
 using System.IO;
 
-using Org.BouncyCastle.Bzip2;
 using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.IO.Compression;
 using Org.BouncyCastle.Utilities.Zlib;
 
 namespace Org.BouncyCastle.Bcpg.OpenPgp
@@ -131,21 +131,21 @@ namespace Org.BouncyCastle.Bcpg.OpenPgp
 
 			switch (algorithm)
 			{
-				case CompressionAlgorithmTag.Uncompressed:
-					dOut = pkOut;
-					break;
-				case CompressionAlgorithmTag.Zip:
-					dOut = new SafeZOutputStream(pkOut, compression, true);
-					break;
-				case CompressionAlgorithmTag.ZLib:
-					dOut = new SafeZOutputStream(pkOut, compression, false);
-					break;
-				case CompressionAlgorithmTag.BZip2:
-					dOut = new SafeCBZip2OutputStream(pkOut);
-					break;
-				default:
-					// Constructor should guard against this possibility
-					throw new InvalidOperationException();
+			case CompressionAlgorithmTag.Uncompressed:
+				dOut = pkOut;
+				break;
+			case CompressionAlgorithmTag.Zip:
+                dOut = Zip.CompressOutput(pkOut, compression, true);
+                break;
+			case CompressionAlgorithmTag.ZLib:
+				dOut = ZLib.CompressOutput(pkOut, compression, true);
+				break;
+			case CompressionAlgorithmTag.BZip2:
+				dOut = Bzip2.CompressOutput(pkOut, true);
+				break;
+			default:
+				// Constructor should guard against this possibility
+				throw new InvalidOperationException();
 			}
 		}
 
@@ -165,31 +165,5 @@ namespace Org.BouncyCastle.Bcpg.OpenPgp
 				pkOut = null;
 			}
 		}
-
-		private class SafeCBZip2OutputStream : CBZip2OutputStream
-		{
-			public SafeCBZip2OutputStream(Stream output)
-				: base(output)
-			{
-			}
-
-            protected override void Dispose(bool disposing)
-            {
-                Detach(disposing);
-            }
-		}
-
-		private class SafeZOutputStream : ZOutputStream
-		{
-			public SafeZOutputStream(Stream output, int level, bool nowrap)
-				: base(output, level, nowrap)
-			{
-			}
-
-            protected override void Dispose(bool disposing)
-            {
-				Detach(disposing);
-            }
-		}
 	}
 }
diff --git a/crypto/src/bzip2/BZip2Constants.cs b/crypto/src/util/bzip2/BZip2Constants.cs
index 81db7fa57..6fc15e55f 100644
--- a/crypto/src/bzip2/BZip2Constants.cs
+++ b/crypto/src/util/bzip2/BZip2Constants.cs
@@ -22,9 +22,7 @@
  * great code.
  */
 
-using System;
-
-namespace Org.BouncyCastle.Bzip2
+namespace Org.BouncyCastle.Utilities.Bzip2
 {
     /**
     * Base class for both the compress and decompress classes.
diff --git a/crypto/src/bzip2/CBZip2InputStream.cs b/crypto/src/util/bzip2/CBZip2InputStream.cs
index b73e52a01..7879f28af 100644
--- a/crypto/src/bzip2/CBZip2InputStream.cs
+++ b/crypto/src/util/bzip2/CBZip2InputStream.cs
@@ -26,10 +26,9 @@ using System;
 using System.Diagnostics;
 using System.IO;
 
-using Org.BouncyCastle.Utilities;
 using Org.BouncyCastle.Utilities.IO;
 
-namespace Org.BouncyCastle.Bzip2
+namespace Org.BouncyCastle.Utilities.Bzip2
 {
 	/**
     * An input stream that decompresses from the BZip2 format (with the file
diff --git a/crypto/src/bzip2/CBZip2OutputStream.cs b/crypto/src/util/bzip2/CBZip2OutputStream.cs
index 5521dce56..b896f36c6 100644
--- a/crypto/src/bzip2/CBZip2OutputStream.cs
+++ b/crypto/src/util/bzip2/CBZip2OutputStream.cs
@@ -27,10 +27,9 @@ using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
 
-using Org.BouncyCastle.Utilities;
 using Org.BouncyCastle.Utilities.IO;
 
-namespace Org.BouncyCastle.Bzip2
+namespace Org.BouncyCastle.Utilities.Bzip2
 {
 	/**
     * An output stream that compresses into the BZip2 format (with the file
@@ -1598,4 +1597,23 @@ namespace Org.BouncyCastle.Bzip2
             return a;
         }
     }
+
+    public class CBZip2OutputStreamLeaveOpen
+        : CBZip2OutputStream
+    {
+        public CBZip2OutputStreamLeaveOpen(Stream outStream)
+            : base(outStream)
+        {
+        }
+
+        public CBZip2OutputStreamLeaveOpen(Stream outStream, int blockSize)
+            : base(outStream, blockSize)
+        {
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            Detach(disposing);
+        }
+    }
 }
diff --git a/crypto/src/bzip2/CRC.cs b/crypto/src/util/bzip2/CRC.cs
index 70d05e084..30c7e9c7d 100644
--- a/crypto/src/bzip2/CRC.cs
+++ b/crypto/src/util/bzip2/CRC.cs
@@ -22,12 +22,9 @@
  * great code.
  */
 
-using System;
 using System.Diagnostics;
 
-using Org.BouncyCastle.Utilities;
-
-namespace Org.BouncyCastle.Bzip2
+namespace Org.BouncyCastle.Utilities.Bzip2
 {
     /**
     * A simple class the hold and calculate the CRC for sanity checking
diff --git a/crypto/src/util/io/compression/Bzip2.cs b/crypto/src/util/io/compression/Bzip2.cs
new file mode 100644
index 000000000..72b006dc9
--- /dev/null
+++ b/crypto/src/util/io/compression/Bzip2.cs
@@ -0,0 +1,21 @@
+using System.IO;
+
+namespace Org.BouncyCastle.Utilities.IO.Compression
+{
+    using Impl = Utilities.Bzip2;
+
+    internal static class Bzip2
+    {
+        internal static Stream CompressOutput(Stream stream, bool leaveOpen = false)
+        {
+            return leaveOpen
+                ?   new Impl.CBZip2OutputStreamLeaveOpen(stream)
+                :   new Impl.CBZip2OutputStream(stream);
+        }
+
+        internal static Stream DecompressInput(Stream stream)
+        {
+            return new Impl.CBZip2InputStream(stream);
+        }
+    }
+}
diff --git a/crypto/src/util/io/compression/ZLib.cs b/crypto/src/util/io/compression/ZLib.cs
new file mode 100644
index 000000000..1254da012
--- /dev/null
+++ b/crypto/src/util/io/compression/ZLib.cs
@@ -0,0 +1,46 @@
+using System.IO;
+
+#if NET6_0_OR_GREATER
+using System.IO.Compression;
+#else
+using Org.BouncyCastle.Utilities.Zlib;
+#endif
+
+namespace Org.BouncyCastle.Utilities.IO.Compression
+{
+    internal static class ZLib
+    {
+        internal static Stream CompressOutput(Stream stream, int zlibCompressionLevel, bool leaveOpen = false)
+        {
+#if NET6_0_OR_GREATER
+            return new ZLibStream(stream, GetCompressionLevel(zlibCompressionLevel), leaveOpen);
+#else
+            return leaveOpen
+                ?   new ZOutputStreamLeaveOpen(stream, zlibCompressionLevel, false)
+                :   new ZOutputStream(stream, zlibCompressionLevel, false);
+#endif
+        }
+
+        internal static Stream DecompressInput(Stream stream)
+        {
+#if NET6_0_OR_GREATER
+            return new ZLibStream(stream, CompressionMode.Decompress, leaveOpen: false);
+#else
+            return new ZInputStream(stream);
+#endif
+        }
+
+#if NET6_0_OR_GREATER
+        internal static CompressionLevel GetCompressionLevel(int zlibCompressionLevel)
+        {
+            return zlibCompressionLevel switch
+            {
+                0           => CompressionLevel.NoCompression,
+                1 or 2 or 3 => CompressionLevel.Fastest,
+                7 or 8 or 9 => CompressionLevel.SmallestSize,
+                _           => CompressionLevel.Optimal,
+            };
+        }
+#endif
+    }
+}
diff --git a/crypto/src/util/io/compression/Zip.cs b/crypto/src/util/io/compression/Zip.cs
new file mode 100644
index 000000000..f2773d63b
--- /dev/null
+++ b/crypto/src/util/io/compression/Zip.cs
@@ -0,0 +1,33 @@
+using System.IO;
+
+#if NET6_0_OR_GREATER
+using System.IO.Compression;
+#else
+using Org.BouncyCastle.Utilities.Zlib;
+#endif
+
+namespace Org.BouncyCastle.Utilities.IO.Compression
+{
+    internal static class Zip
+    {
+        internal static Stream CompressOutput(Stream stream, int zlibCompressionLevel, bool leaveOpen = false)
+        {
+#if NET6_0_OR_GREATER
+            return new DeflateStream(stream, ZLib.GetCompressionLevel(zlibCompressionLevel), leaveOpen);
+#else
+            return leaveOpen
+                ?   new ZOutputStreamLeaveOpen(stream, zlibCompressionLevel, true)
+                :   new ZOutputStream(stream, zlibCompressionLevel, true);
+#endif
+        }
+
+        internal static Stream DecompressInput(Stream stream)
+        {
+#if NET6_0_OR_GREATER
+            return new DeflateStream(stream, CompressionMode.Decompress, leaveOpen: false);
+#else
+            return new ZInputStream(stream, true);
+#endif
+        }
+    }
+}
diff --git a/crypto/src/util/zlib/ZOutputStream.cs b/crypto/src/util/zlib/ZOutputStream.cs
index 301516e57..51a5050dd 100644
--- a/crypto/src/util/zlib/ZOutputStream.cs
+++ b/crypto/src/util/zlib/ZOutputStream.cs
@@ -264,4 +264,38 @@ namespace Org.BouncyCastle.Utilities.Zlib
             Write(buf1, 0, 1);
         }
     }
+
+    public class ZOutputStreamLeaveOpen
+        : ZOutputStream
+    {
+        public ZOutputStreamLeaveOpen(Stream output)
+            : base(output)
+        {
+        }
+
+        public ZOutputStreamLeaveOpen(Stream output, bool nowrap)
+            : base(output, nowrap)
+        {
+        }
+
+        public ZOutputStreamLeaveOpen(Stream output, ZStream z)
+            : base(output, z)
+        {
+        }
+
+        public ZOutputStreamLeaveOpen(Stream output, int level)
+            : base(output, level)
+        {
+        }
+
+        public ZOutputStreamLeaveOpen(Stream output, int level, bool nowrap)
+            : base(output, level, nowrap)
+        {
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            Detach(disposing);
+        }
+    }
 }