more reverts

# Conflicts:
#	src/SharpCompress/Writers/Zip/ZipWriter.cs

.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "csharpier": {
-      "version": "0.25.0",
+      "version": "0.27.3",
       "commands": [
         "dotnet-csharpier"
       ]

.github/workflows/dotnetcore.yml

@@ -15,18 +15,11 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-    - uses: actions/setup-dotnet@v3
+    - uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: 7.0.x
-    - name: NuGet Caching
-      uses: actions/cache@v3
-      with:
-        path: ~/.nuget/packages
-        key: ${{ runner.os }}-nuget-${{ hashFiles('packages.lock.json', '*/packages.lock.json') }}
-        restore-keys: |
-            ${{ runner.os }}-nuget-
+        dotnet-version: 8.0.x
     - run: dotnet run --project build/build.csproj
-    - uses: actions/upload-artifact@v3
+    - uses: actions/upload-artifact@v4
       with:
         name: ${{ matrix.os }}-sharpcompress.nupkg
         path: artifacts/*

README.md

@@ -36,7 +36,7 @@ I'm always looking for help or ideas. Please submit code or email with ideas. Un
 
 ## TODOs (always lots)
 
-* RAR 5 decryption support
+* RAR 5 decryption crc check support
 * 7Zip writing
 * Zip64 (Need writing and extend Reading)
 * Multi-volume Zip support.

build/Program.cs

@@ -61,7 +61,7 @@ Target(
 Target(
     Test,
     DependsOn(Build),
-    ForEach("net7.0", "net462"),
+    ForEach("net8.0", "net462"),
     framework =>
     {
         IEnumerable<string> GetFiles(string d)

global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "7.0.101",
+    "version": "8.0.100",
     "rollForward": "latestFeature"
   }
 }

src/SharpCompress/Algorithms/Adler32.cs

@@ -62,7 +62,7 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
         public static int ReduceSum(Vector256<int> accumulator)
         {
             // Add upper lane to lower lane.
-            Vector128<int> vsum = Sse2.Add(accumulator.GetLower(), accumulator.GetUpper());
+            var vsum = Sse2.Add(accumulator.GetLower(), accumulator.GetUpper());
 
             // Add odd to even.
             vsum = Sse2.Add(vsum, Sse2.Shuffle(vsum, 0b_11_11_01_01));
@@ -81,7 +81,7 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int EvenReduceSum(Vector256<int> accumulator)
         {
-            Vector128<int> vsum = Sse2.Add(accumulator.GetLower(), accumulator.GetUpper()); // add upper lane to lower lane
+            var vsum = Sse2.Add(accumulator.GetLower(), accumulator.GetUpper()); // add upper lane to lower lane
             vsum = Sse2.Add(vsum, Sse2.Shuffle(vsum, 0b_11_10_11_10)); // add high to low
 
             // Vector128<int>.ToScalar() isn't optimized pre-net5.0 https://github.com/dotnet/runtime/pull/37882
@@ -189,29 +189,29 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
     [MethodImpl(InliningOptions.HotPath | InliningOptions.ShortMethod)]
     private static unsafe uint CalculateSse(uint adler, ReadOnlySpan<byte> buffer)
     {
-        uint s1 = adler & 0xFFFF;
-        uint s2 = (adler >> 16) & 0xFFFF;
+        var s1 = adler & 0xFFFF;
+        var s2 = (adler >> 16) & 0xFFFF;
 
         // Process the data in blocks.
-        uint length = (uint)buffer.Length;
-        uint blocks = length / BlockSize;
+        var length = (uint)buffer.Length;
+        var blocks = length / BlockSize;
         length -= blocks * BlockSize;
 
         fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
         {
             fixed (byte* tapPtr = &MemoryMarshal.GetReference(Tap1Tap2))
             {
-                byte* localBufferPtr = bufferPtr;
+                var localBufferPtr = bufferPtr;
 
                 // _mm_setr_epi8 on x86
-                Vector128<sbyte> tap1 = Sse2.LoadVector128((sbyte*)tapPtr);
-                Vector128<sbyte> tap2 = Sse2.LoadVector128((sbyte*)(tapPtr + 0x10));
-                Vector128<byte> zero = Vector128<byte>.Zero;
+                var tap1 = Sse2.LoadVector128((sbyte*)tapPtr);
+                var tap2 = Sse2.LoadVector128((sbyte*)(tapPtr + 0x10));
+                var zero = Vector128<byte>.Zero;
                 var ones = Vector128.Create((short)1);
 
                 while (blocks > 0)
                 {
-                    uint n = NMAX / BlockSize; /* The NMAX constraint. */
+                    var n = NMAX / BlockSize; /* The NMAX constraint. */
                     if (n > blocks)
                     {
                         n = blocks;
@@ -221,15 +221,15 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
 
                     // Process n blocks of data. At most NMAX data bytes can be
                     // processed before s2 must be reduced modulo BASE.
-                    Vector128<uint> v_ps = Vector128.CreateScalar(s1 * n);
-                    Vector128<uint> v_s2 = Vector128.CreateScalar(s2);
-                    Vector128<uint> v_s1 = Vector128<uint>.Zero;
+                    var v_ps = Vector128.CreateScalar(s1 * n);
+                    var v_s2 = Vector128.CreateScalar(s2);
+                    var v_s1 = Vector128<uint>.Zero;
 
                     do
                     {
                         // Load 32 input bytes.
-                        Vector128<byte> bytes1 = Sse3.LoadDquVector128(localBufferPtr);
-                        Vector128<byte> bytes2 = Sse3.LoadDquVector128(localBufferPtr + 0x10);
+                        var bytes1 = Sse3.LoadDquVector128(localBufferPtr);
+                        var bytes2 = Sse3.LoadDquVector128(localBufferPtr + 0x10);
 
                         // Add previous block byte sum to v_ps.
                         v_ps = Sse2.Add(v_ps, v_s1);
@@ -237,11 +237,11 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
                         // Horizontally add the bytes for s1, multiply-adds the
                         // bytes by [ 32, 31, 30, ... ] for s2.
                         v_s1 = Sse2.Add(v_s1, Sse2.SumAbsoluteDifferences(bytes1, zero).AsUInt32());
-                        Vector128<short> mad1 = Ssse3.MultiplyAddAdjacent(bytes1, tap1);
+                        var mad1 = Ssse3.MultiplyAddAdjacent(bytes1, tap1);
                         v_s2 = Sse2.Add(v_s2, Sse2.MultiplyAddAdjacent(mad1, ones).AsUInt32());
 
                         v_s1 = Sse2.Add(v_s1, Sse2.SumAbsoluteDifferences(bytes2, zero).AsUInt32());
-                        Vector128<short> mad2 = Ssse3.MultiplyAddAdjacent(bytes2, tap2);
+                        var mad2 = Ssse3.MultiplyAddAdjacent(bytes2, tap2);
                         v_s2 = Sse2.Add(v_s2, Sse2.MultiplyAddAdjacent(mad2, ones).AsUInt32());
 
                         localBufferPtr += BlockSize;
@@ -281,15 +281,15 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
     [MethodImpl(InliningOptions.HotPath | InliningOptions.ShortMethod)]
     public static unsafe uint CalculateAvx2(uint adler, ReadOnlySpan<byte> buffer)
     {
-        uint s1 = adler & 0xFFFF;
-        uint s2 = (adler >> 16) & 0xFFFF;
-        uint length = (uint)buffer.Length;
+        var s1 = adler & 0xFFFF;
+        var s2 = (adler >> 16) & 0xFFFF;
+        var length = (uint)buffer.Length;
 
         fixed (byte* bufferPtr = &MemoryMarshal.GetReference(buffer))
         {
-            byte* localBufferPtr = bufferPtr;
+            var localBufferPtr = bufferPtr;
 
-            Vector256<byte> zero = Vector256<byte>.Zero;
+            var zero = Vector256<byte>.Zero;
             var dot3v = Vector256.Create((short)1);
             var dot2v = Vector256.Create(
                 32,
@@ -333,29 +333,29 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
 
             while (length >= 32)
             {
-                int k = length < NMAX ? (int)length : (int)NMAX;
+                var k = length < NMAX ? (int)length : (int)NMAX;
                 k -= k % 32;
                 length -= (uint)k;
 
-                Vector256<uint> vs10 = vs1;
-                Vector256<uint> vs3 = Vector256<uint>.Zero;
+                var vs10 = vs1;
+                var vs3 = Vector256<uint>.Zero;
 
                 while (k >= 32)
                 {
                     // Load 32 input bytes.
-                    Vector256<byte> block = Avx.LoadVector256(localBufferPtr);
+                    var block = Avx.LoadVector256(localBufferPtr);
 
                     // Sum of abs diff, resulting in 2 x int32's
-                    Vector256<ushort> vs1sad = Avx2.SumAbsoluteDifferences(block, zero);
+                    var vs1sad = Avx2.SumAbsoluteDifferences(block, zero);
 
                     vs1 = Avx2.Add(vs1, vs1sad.AsUInt32());
                     vs3 = Avx2.Add(vs3, vs10);
 
                     // sum 32 uint8s to 16 shorts.
-                    Vector256<short> vshortsum2 = Avx2.MultiplyAddAdjacent(block, dot2v);
+                    var vshortsum2 = Avx2.MultiplyAddAdjacent(block, dot2v);
 
                     // sum 16 shorts to 8 uint32s.
-                    Vector256<int> vsum2 = Avx2.MultiplyAddAdjacent(vshortsum2, dot3v);
+                    var vsum2 = Avx2.MultiplyAddAdjacent(vshortsum2, dot3v);
 
                     vs2 = Avx2.Add(vsum2.AsUInt32(), vs2);
                     vs10 = vs1;
@@ -434,14 +434,14 @@ internal static class Adler32 // From https://github.com/SixLabors/ImageSharp/bl
     [MethodImpl(InliningOptions.HotPath | InliningOptions.ShortMethod)]
     private static unsafe uint CalculateScalar(uint adler, ReadOnlySpan<byte> buffer)
     {
-        uint s1 = adler & 0xFFFF;
-        uint s2 = (adler >> 16) & 0xFFFF;
+        var s1 = adler & 0xFFFF;
+        var s2 = (adler >> 16) & 0xFFFF;
         uint k;
 
         fixed (byte* bufferPtr = buffer)
         {
             var localBufferPtr = bufferPtr;
-            uint length = (uint)buffer.Length;
+            var length = (uint)buffer.Length;
 
             while (length > 0)
             {

src/SharpCompress/Archives/AbstractWritableArchive.cs

@@ -31,10 +31,10 @@ public abstract class AbstractWritableArchive<TEntry, TVolume>
         }
     }
 
-    private readonly List<TEntry> newEntries = new List<TEntry>();
-    private readonly List<TEntry> removedEntries = new List<TEntry>();
+    private readonly List<TEntry> newEntries = new();
+    private readonly List<TEntry> removedEntries = new();
 
-    private readonly List<TEntry> modifiedEntries = new List<TEntry>();
+    private readonly List<TEntry> modifiedEntries = new();
     private bool hasModifications;
     private bool pauseRebuilding;
 

src/SharpCompress/Archives/ArchiveFactory.cs

@@ -25,8 +25,8 @@ public static class ArchiveFactory
 
     public static IWritableArchive Create(ArchiveType type)
     {
-        var factory = Factory.Factories
-            .OfType<IWriteableArchiveFactory>()
+        var factory = Factory
+            .Factories.OfType<IWriteableArchiveFactory>()
             .FirstOrDefault(item => item.KnownArchiveType == type);
 
         if (factory != null)

src/SharpCompress/Archives/ArchiveVolumeFactory.cs

@@ -11,7 +11,7 @@ internal abstract class ArchiveVolumeFactory
         FileInfo? item = null;
 
         //split 001, 002 ...
-        Match m = Regex.Match(part1.Name, @"^(.*\.)([0-9]+)$", RegexOptions.IgnoreCase);
+        var m = Regex.Match(part1.Name, @"^(.*\.)([0-9]+)$", RegexOptions.IgnoreCase);
         if (m.Success)
             item = new FileInfo(
                 Path.Combine(

src/SharpCompress/Archives/GZip/GZipArchive.cs

@@ -94,7 +94,7 @@ public class GZipArchive : AbstractWritableArchive<GZipArchiveEntry, GZipVolume>
         );
     }
 
-    public static GZipArchive Create() => new GZipArchive();
+    public static GZipArchive Create() => new();
 
     /// <summary>
     /// Constructor with a SourceStream able to handle FileInfo and Streams.

src/SharpCompress/Archives/Rar/RarArchive.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -14,9 +15,8 @@ namespace SharpCompress.Archives.Rar;
 public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
 {
     internal Lazy<IRarUnpack> UnpackV2017 { get; } =
-        new Lazy<IRarUnpack>(() => new Compressors.Rar.UnpackV2017.Unpack());
-    internal Lazy<IRarUnpack> UnpackV1 { get; } =
-        new Lazy<IRarUnpack>(() => new Compressors.Rar.UnpackV1.Unpack());
+        new(() => new Compressors.Rar.UnpackV2017.Unpack());
+    internal Lazy<IRarUnpack> UnpackV1 { get; } = new(() => new Compressors.Rar.UnpackV1.Unpack());
 
     /// <summary>
     /// Constructor with a SourceStream able to handle FileInfo and Streams.
@@ -40,9 +40,11 @@ public class RarArchive : AbstractArchive<RarArchiveEntry, RarVolume>
             streams[1].Position = 0;
             SrcStream.Position = 0;
 
-            return srcStream.Streams.Select(
-                a => new StreamRarArchiveVolume(a, ReaderOptions, idx++)
-            );
+            return srcStream.Streams.Select(a => new StreamRarArchiveVolume(
+                a,
+                ReaderOptions,
+                idx++
+            ));
         }
         else //split mode or single file
         {

src/SharpCompress/Archives/Rar/RarArchiveEntry.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -40,7 +41,10 @@ public class RarArchiveEntry : RarEntry, IArchiveEntry
         get
         {
             CheckIncomplete();
-            return parts.Select(fp => fp.FileHeader).Single(fh => !fh.IsSplitAfter).FileCrc;
+            return BitConverter.ToUInt32(
+                parts.Select(fp => fp.FileHeader).Single(fh => !fh.IsSplitAfter).FileCrc,
+                0
+            );
         }
     }
 

src/SharpCompress/Archives/Rar/RarArchiveVolumeFactory.cs

@@ -11,7 +11,7 @@ internal static class RarArchiveVolumeFactory
         FileInfo? item = null;
 
         //new style rar - ..part1 | /part01 | part001 ....
-        Match m = Regex.Match(part1.Name, @"^(.*\.part)([0-9]+)(\.rar)$", RegexOptions.IgnoreCase);
+        var m = Regex.Match(part1.Name, @"^(.*\.part)([0-9]+)(\.rar)$", RegexOptions.IgnoreCase);
         if (m.Success)
             item = new FileInfo(
                 Path.Combine(

src/SharpCompress/Archives/Rar/SeekableFilePart.cs

@@ -25,10 +25,19 @@ internal class SeekableFilePart : RarFilePart
     internal override Stream GetCompressedStream()
     {
         stream.Position = FileHeader.DataStartPosition;
+
         if (FileHeader.R4Salt != null)
         {
-            return new RarCryptoWrapper(stream, password!, FileHeader.R4Salt);
+            var cryptKey = new CryptKey3(password!);
+            return new RarCryptoWrapper(stream, FileHeader.R4Salt, cryptKey);
         }
+
+        if (FileHeader.Rar5CryptoInfo != null)
+        {
+            var cryptKey = new CryptKey5(password!, FileHeader.Rar5CryptoInfo);
+            return new RarCryptoWrapper(stream, FileHeader.Rar5CryptoInfo.Salt, cryptKey);
+        }
+
         return stream;
     }
 

src/SharpCompress/Archives/Tar/TarArchive.cs

@@ -195,7 +195,7 @@ public class TarArchive : AbstractWritableArchive<TarArchiveEntry, TarVolume>
         }
     }
 
-    public static TarArchive Create() => new TarArchive();
+    public static TarArchive Create() => new();
 
     protected override TarArchiveEntry CreateEntryInternal(
         string filePath,

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -294,7 +294,7 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         bool closeStream
     ) => new ZipWritableArchiveEntry(this, source, filePath, size, modified, closeStream);
 
-    public static ZipArchive Create() => new ZipArchive();
+    public static ZipArchive Create() => new();
 
     protected override IReader CreateReaderForSolidExtraction()
     {

src/SharpCompress/Archives/Zip/ZipArchiveVolumeFactory.cs

@@ -12,7 +12,7 @@ internal static class ZipArchiveVolumeFactory
 
         //load files with zip/zipx first. Swapped to end once loaded in ZipArchive
         //new style .zip, z01.. | .zipx, zx01 - if the numbers go beyond 99 then they use 100 ...1000 etc
-        Match m = Regex.Match(part1.Name, @"^(.*\.)(zipx?|zx?[0-9]+)$", RegexOptions.IgnoreCase);
+        var m = Regex.Match(part1.Name, @"^(.*\.)(zipx?|zx?[0-9]+)$", RegexOptions.IgnoreCase);
         if (m.Success)
             item = new FileInfo(
                 Path.Combine(

src/SharpCompress/BufferPool.cs

@@ -0,0 +1,33 @@
+using System.Buffers;
+
+namespace SharpCompress;
+
+internal static class BufferPool
+{
+    /// <summary>
+    ///     gets a buffer from the pool
+    /// </summary>
+    /// <param name="bufferSize">size of the buffer</param>
+    /// <returns>the buffer</returns>
+    public static byte[] Rent(int bufferSize)
+    {
+#if NETCOREAPP || NETSTANDARD2_1_OR_GREATER
+        return ArrayPool<byte>.Shared.Rent(bufferSize);
+#else
+        return new byte[bufferSize];
+#endif
+    }
+
+    /// <summary>
+    ///     returns a buffer to the pool
+    /// </summary>
+    /// <param name="buffer">the buffer to return</param>
+    public static void Return(byte[] buffer)
+    {
+#if NETCOREAPP || NETSTANDARD2_1_OR_GREATER
+        ArrayPool<byte>.Shared.Return(buffer);
+#else
+        // no-op
+#endif
+    }
+}

src/SharpCompress/Common/CompressionType.cs

@@ -14,5 +14,7 @@ public enum CompressionType
     LZip,
     Xz,
     Unknown,
-    Deflate64
+    Deflate64,
+    Shrink,
+    Lzw
 }

src/SharpCompress/Common/ExtractionMethods.cs

@@ -16,7 +16,7 @@ internal static class ExtractionMethods
     )
     {
         string destinationFileName;
-        string fullDestinationDirectoryPath = Path.GetFullPath(destinationDirectory);
+        var fullDestinationDirectoryPath = Path.GetFullPath(destinationDirectory);
 
         //check for trailing slash.
         if (
@@ -36,11 +36,11 @@ internal static class ExtractionMethods
 
         options ??= new ExtractionOptions() { Overwrite = true };
 
-        string file = Path.GetFileName(entry.Key);
+        var file = Path.GetFileName(entry.Key);
         if (options.ExtractFullPath)
         {
-            string folder = Path.GetDirectoryName(entry.Key)!;
-            string destdir = Path.GetFullPath(Path.Combine(fullDestinationDirectoryPath, folder));
+            var folder = Path.GetDirectoryName(entry.Key)!;
+            var destdir = Path.GetFullPath(Path.Combine(fullDestinationDirectoryPath, folder));
 
             if (!Directory.Exists(destdir))
             {
@@ -102,7 +102,7 @@ internal static class ExtractionMethods
         }
         else
         {
-            FileMode fm = FileMode.Create;
+            var fm = FileMode.Create;
             options ??= new ExtractionOptions() { Overwrite = true };
 
             if (!options.Overwrite)

src/SharpCompress/Common/OptionsBase.cs

@@ -7,5 +7,5 @@ public class OptionsBase
     /// </summary>
     public bool LeaveStreamOpen { get; set; } = true;
 
-    public ArchiveEncoding ArchiveEncoding { get; set; } = new ArchiveEncoding();
+    public ArchiveEncoding ArchiveEncoding { get; set; } = new();
 }

src/SharpCompress/Common/PasswordProtectedException.cs

@@ -1,12 +0,0 @@
-using System;
-
-namespace SharpCompress.Common;
-
-public class PasswordProtectedException : ExtractionException
-{
-    public PasswordProtectedException(string message)
-        : base(message) { }
-
-    public PasswordProtectedException(string message, Exception inner)
-        : base(message, inner) { }
-}

src/SharpCompress/Common/Rar/CryptKey3.cs

@@ -0,0 +1,84 @@
+#nullable disable
+
+using System.Security.Cryptography;
+using System.Text;
+using SharpCompress.Common.Rar.Headers;
+
+namespace SharpCompress.Common.Rar;
+
+internal class CryptKey3 : ICryptKey
+{
+    const int AES_128 = 128;
+
+    private string _password;
+
+    public CryptKey3(string password) => _password = password ?? "";
+
+    public ICryptoTransform Transformer(byte[] salt)
+    {
+        var aesIV = new byte[EncryptionConstV5.SIZE_INITV];
+
+        var rawLength = 2 * _password.Length;
+        var rawPassword = new byte[rawLength + EncryptionConstV5.SIZE_SALT30];
+        var passwordBytes = Encoding.UTF8.GetBytes(_password);
+        for (var i = 0; i < _password.Length; i++)
+        {
+            rawPassword[i * 2] = passwordBytes[i];
+            rawPassword[(i * 2) + 1] = 0;
+        }
+
+        for (var i = 0; i < salt.Length; i++)
+        {
+            rawPassword[i + rawLength] = salt[i];
+        }
+
+        var msgDigest = SHA1.Create();
+        const int noOfRounds = (1 << 18);
+        const int iblock = 3;
+
+        byte[] digest;
+        var data = new byte[(rawPassword.Length + iblock) * noOfRounds];
+
+        //TODO slow code below, find ways to optimize
+        for (var i = 0; i < noOfRounds; i++)
+        {
+            rawPassword.CopyTo(data, i * (rawPassword.Length + iblock));
+
+            data[(i * (rawPassword.Length + iblock)) + rawPassword.Length + 0] = (byte)i;
+            data[(i * (rawPassword.Length + iblock)) + rawPassword.Length + 1] = (byte)(i >> 8);
+            data[(i * (rawPassword.Length + iblock)) + rawPassword.Length + 2] = (byte)(i >> 16);
+
+            if (i % (noOfRounds / EncryptionConstV5.SIZE_INITV) == 0)
+            {
+                digest = msgDigest.ComputeHash(data, 0, (i + 1) * (rawPassword.Length + iblock));
+                aesIV[i / (noOfRounds / EncryptionConstV5.SIZE_INITV)] = digest[19];
+            }
+        }
+        digest = msgDigest.ComputeHash(data);
+        //slow code ends
+
+        var aesKey = new byte[EncryptionConstV5.SIZE_INITV];
+        for (var i = 0; i < 4; i++)
+        {
+            for (var j = 0; j < 4; j++)
+            {
+                aesKey[(i * 4) + j] = (byte)(
+                    (
+                        ((digest[i * 4] * 0x1000000) & 0xff000000)
+                        | (uint)((digest[(i * 4) + 1] * 0x10000) & 0xff0000)
+                        | (uint)((digest[(i * 4) + 2] * 0x100) & 0xff00)
+                        | (uint)(digest[(i * 4) + 3] & 0xff)
+                    ) >> (j * 8)
+                );
+            }
+        }
+
+        var aes = Aes.Create();
+        aes.KeySize = AES_128;
+        aes.Mode = CipherMode.CBC;
+        aes.Padding = PaddingMode.None;
+        aes.Key = aesKey;
+        aes.IV = aesIV;
+        return aes.CreateDecryptor();
+    }
+}

src/SharpCompress/Common/Rar/CryptKey5.cs

@@ -0,0 +1,95 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using SharpCompress.Common.Rar.Headers;
+
+namespace SharpCompress.Common.Rar;
+
+internal class CryptKey5 : ICryptKey
+{
+    const int AES_256 = 256;
+    const int DERIVED_KEY_LENGTH = 0x10;
+    const int SHA256_DIGEST_SIZE = 32;
+
+    private string _password;
+    private Rar5CryptoInfo _cryptoInfo;
+    private byte[] _pswCheck = { };
+    private byte[] _hashKey = { };
+
+    public CryptKey5(string password, Rar5CryptoInfo rar5CryptoInfo)
+    {
+        _password = password ?? "";
+        _cryptoInfo = rar5CryptoInfo;
+    }
+
+    public byte[] PswCheck => _pswCheck;
+
+    public byte[] HashKey => _hashKey;
+
+    private static List<byte[]> GenerateRarPBKDF2Key(
+        string password,
+        byte[] salt,
+        int iterations,
+        int keyLength
+    )
+    {
+        using var hmac = new HMACSHA256(Encoding.UTF8.GetBytes(password));
+        var block = hmac.ComputeHash(salt);
+        var finalHash = (byte[])block.Clone();
+
+        var loop = new int[] { iterations, 17, 17 };
+        var res = new List<byte[]> { };
+
+        for (var x = 0; x < 3; x++)
+        {
+            for (var i = 1; i < loop[x]; i++)
+            {
+                block = hmac.ComputeHash(block);
+                for (var j = 0; j < finalHash.Length; j++)
+                {
+                    finalHash[j] ^= block[j];
+                }
+            }
+
+            res.Add((byte[])finalHash.Clone());
+        }
+
+        return res;
+    }
+
+    public ICryptoTransform Transformer(byte[] salt)
+    {
+        var iterations = (1 << _cryptoInfo.LG2Count); // Adjust the number of iterations as needed
+
+        var salt_rar5 = salt.Concat(new byte[] { 0, 0, 0, 1 });
+        var derivedKey = GenerateRarPBKDF2Key(
+            _password,
+            salt_rar5.ToArray(),
+            iterations,
+            DERIVED_KEY_LENGTH
+        );
+
+        _hashKey = derivedKey[1];
+
+        _pswCheck = new byte[EncryptionConstV5.SIZE_PSWCHECK];
+
+        for (var i = 0; i < SHA256_DIGEST_SIZE; i++)
+        {
+            _pswCheck[i % EncryptionConstV5.SIZE_PSWCHECK] ^= derivedKey[2][i];
+        }
+
+        if (_cryptoInfo.UsePswCheck && !_cryptoInfo.PswCheck.SequenceEqual(_pswCheck))
+        {
+            throw new CryptographicException("The password did not match.");
+        }
+
+        var aes = Aes.Create();
+        aes.KeySize = AES_256;
+        aes.Mode = CipherMode.CBC;
+        aes.Padding = PaddingMode.None;
+        aes.Key = derivedKey[0];
+        aes.IV = _cryptoInfo.InitV;
+        return aes.CreateDecryptor();
+    }
+}

src/SharpCompress/Common/Rar/Headers/ArchiveCryptHeader.cs

@@ -1,50 +1,19 @@
 #nullable disable
 
+using System;
+using System.Security.Cryptography;
+using SharpCompress.Common.Rar.Headers;
 using SharpCompress.IO;
 
 namespace SharpCompress.Common.Rar.Headers;
 
 internal class ArchiveCryptHeader : RarHeader
 {
-    private const int CRYPT_VERSION = 0; // Supported encryption version.
-    private const int SIZE_SALT50 = 16;
-    private const int SIZE_PSWCHECK = 8;
-    private const int SIZE_PSWCHECK_CSUM = 4;
-    private const int CRYPT5_KDF_LG2_COUNT_MAX = 24; // LOG2 of maximum accepted iteration count.
-
-    private bool _usePswCheck;
-    private uint _lg2Count; // Log2 of PBKDF2 repetition count.
-    private byte[] _salt;
-    private byte[] _pswCheck;
-    private byte[] _pswCheckCsm;
-
     public ArchiveCryptHeader(RarHeader header, RarCrcBinaryReader reader)
         : base(header, reader, HeaderType.Crypt) { }
 
-    protected override void ReadFinish(MarkingBinaryReader reader)
-    {
-        var cryptVersion = reader.ReadRarVIntUInt32();
-        if (cryptVersion > CRYPT_VERSION)
-        {
-            //error?
-            return;
-        }
-        var encryptionFlags = reader.ReadRarVIntUInt32();
-        _usePswCheck = FlagUtility.HasFlag(encryptionFlags, EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK);
-        _lg2Count = reader.ReadRarVIntByte(1);
+    public Rar5CryptoInfo CryptInfo = new();
 
-        //UsePswCheck = HasHeaderFlag(EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK);
-        if (_lg2Count > CRYPT5_KDF_LG2_COUNT_MAX)
-        {
-            //error?
-            return;
-        }
-
-        _salt = reader.ReadBytes(SIZE_SALT50);
-        if (_usePswCheck)
-        {
-            _pswCheck = reader.ReadBytes(SIZE_PSWCHECK);
-            _pswCheckCsm = reader.ReadBytes(SIZE_PSWCHECK_CSUM);
-        }
-    }
+    protected override void ReadFinish(MarkingBinaryReader reader) =>
+        CryptInfo = new Rar5CryptoInfo(reader, false);
 }

src/SharpCompress/Common/Rar/Headers/FileHeader.cs

@@ -1,5 +1,11 @@
 #nullable disable
 
+using System;
+using System.IO;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using SharpCompress.IO;
 #if !Rar2017_64bit
 using size_t = System.UInt32;
 #else
@@ -8,16 +14,11 @@ using nuint = System.UInt64;
 using size_t = System.UInt64;
 #endif
 
-using SharpCompress.IO;
-using System;
-using System.IO;
-using System.Text;
-
 namespace SharpCompress.Common.Rar.Headers;
 
 internal class FileHeader : RarHeader
 {
-    private uint _fileCrc;
+    private byte[] _hash;
 
     public FileHeader(RarHeader header, RarCrcBinaryReader reader, HeaderType headerType)
         : base(header, reader, headerType) { }
@@ -52,7 +53,7 @@ internal class FileHeader : RarHeader
 
         if (HasFlag(FileFlagsV5.HAS_CRC32))
         {
-            FileCrc = reader.ReadUInt32();
+            FileCrc = reader.ReadBytes(4);
         }
 
         var compressionInfo = reader.ReadRarVIntUInt16();
@@ -104,7 +105,13 @@ internal class FileHeader : RarHeader
             throw new InvalidFormatException("rar5 header size / extra size inconsistency");
         }
 
-        isEncryptedRar5 = false;
+        const ushort FHEXTRA_CRYPT = 0x01;
+        const ushort FHEXTRA_HASH = 0x02;
+        const ushort FHEXTRA_HTIME = 0x03;
+        // const ushort FHEXTRA_VERSION = 0x04;
+        const ushort FHEXTRA_REDIR = 0x05;
+        // const ushort FHEXTRA_UOWNER = 0x06;
+        // const ushort FHEXTRA_SUBDATA = 0x07;
 
         while (RemainingHeaderBytes(reader) > 0)
         {
@@ -113,22 +120,32 @@ internal class FileHeader : RarHeader
             var type = reader.ReadRarVIntUInt16();
             switch (type)
             {
-                //TODO
-                case 1: // file encryption
+                case FHEXTRA_CRYPT: // file encryption
 
                     {
-                        isEncryptedRar5 = true;
+                        Rar5CryptoInfo = new Rar5CryptoInfo(reader, true);
 
-                        //var version = reader.ReadRarVIntByte();
-                        //if (version != 0) throw new InvalidFormatException("unknown encryption algorithm " + version);
+                        if (Rar5CryptoInfo.PswCheck.All(singleByte => singleByte == 0))
+                        {
+                            Rar5CryptoInfo = null;
+                        }
                     }
                     break;
-                //                    case 2: // file hash
-                //                        {
-                //
-                //                        }
-                //                        break;
-                case 3: // file time
+                case FHEXTRA_HASH:
+
+                    {
+                        const uint FHEXTRA_HASH_BLAKE2 = 0x0;
+                        //                        const uint HASH_BLAKE2 = 0x03;
+                        const int BLAKE2_DIGEST_SIZE = 0x20;
+                        if ((uint)reader.ReadRarVInt() == FHEXTRA_HASH_BLAKE2)
+                        {
+                            //                            var hash = HASH_BLAKE2;
+                            _hash = reader.ReadBytes(BLAKE2_DIGEST_SIZE);
+                        }
+                        // enum HASH_TYPE {HASH_NONE,HASH_RAR14,HASH_CRC32,HASH_BLAKE2};
+                    }
+                    break;
+                case FHEXTRA_HTIME: // file time
 
                     {
                         var flags = reader.ReadRarVIntUInt16();
@@ -148,22 +165,28 @@ internal class FileHeader : RarHeader
                     }
                     break;
                 //TODO
-                //                    case 4: // file version
+                //                    case FHEXTRA_VERSION: // file version
                 //                        {
                 //
                 //                        }
                 //                        break;
-                //                    case 5: // file system redirection
+                case FHEXTRA_REDIR: // file system redirection
+
+                    {
+                        RedirType = reader.ReadRarVIntByte();
+                        RedirFlags = reader.ReadRarVIntByte();
+                        var nn = reader.ReadRarVIntUInt16();
+                        var bb = reader.ReadBytes(nn);
+                        RedirTargetName = ConvertPathV5(Encoding.UTF8.GetString(bb, 0, bb.Length));
+                    }
+                    break;
+                //TODO
+                //                    case FHEXTRA_UOWNER: // unix owner
                 //                        {
                 //
                 //                        }
                 //                        break;
-                //                    case 6: // unix owner
-                //                        {
-                //
-                //                        }
-                //                        break;
-                //                    case 7: // service data
+                //                    case FHEXTRA_SUBDATA: // service data
                 //                        {
                 //
                 //                        }
@@ -171,6 +194,7 @@ internal class FileHeader : RarHeader
 
                 default:
                     // skip unknown record types to allow new record types to be added in the future
+                    //Console.WriteLine($"unhandled rar header field type {type}");
                     break;
             }
             // drain any trailing bytes of extra record
@@ -222,7 +246,7 @@ internal class FileHeader : RarHeader
 
         HostOs = reader.ReadByte();
 
-        FileCrc = reader.ReadUInt32();
+        FileCrc = reader.ReadBytes(4);
 
         FileLastModifiedTime = Utility.DosDateToDateTime(reader.ReadUInt32());
 
@@ -255,7 +279,6 @@ internal class FileHeader : RarHeader
 
         var fileNameBytes = reader.ReadBytes(nameSize);
 
-        const int saltSize = 8;
         const int newLhdSize = 32;
 
         switch (HeaderCode)
@@ -293,7 +316,7 @@ internal class FileHeader : RarHeader
                     var datasize = HeaderSize - newLhdSize - nameSize;
                     if (HasFlag(FileFlagsV4.SALT))
                     {
-                        datasize -= saltSize;
+                        datasize -= EncryptionConstV5.SIZE_SALT30;
                     }
                     if (datasize > 0)
                     {
@@ -314,7 +337,7 @@ internal class FileHeader : RarHeader
 
         if (HasFlag(FileFlagsV4.SALT))
         {
-            R4Salt = reader.ReadBytes(saltSize);
+            R4Salt = reader.ReadBytes(EncryptionConstV5.SIZE_SALT30);
         }
         if (HasFlag(FileFlagsV4.EXT_TIME))
         {
@@ -395,18 +418,10 @@ internal class FileHeader : RarHeader
 
     private bool HasFlag(ushort flag) => (Flags & flag) == flag;
 
-    internal uint FileCrc
+    internal byte[] FileCrc
     {
-        get
-        {
-            if (IsRar5 && !HasFlag(FileFlagsV5.HAS_CRC32))
-            {
-                //!!! rar5:
-                throw new InvalidOperationException("TODO rar5");
-            }
-            return _fileCrc;
-        }
-        private set => _fileCrc = value;
+        get => _hash;
+        private set => _hash = value;
     }
 
     // 0 - storing
@@ -428,11 +443,17 @@ internal class FileHeader : RarHeader
 
     public bool IsSolid { get; private set; }
 
+    public byte RedirType { get; private set; }
+    public bool IsRedir => RedirType != 0;
+    public byte RedirFlags { get; private set; }
+    public bool IsRedirDirectory => (RedirFlags & RedirFlagV5.DIRECTORY) != 0;
+    public string RedirTargetName { get; private set; }
+
     // unused for UnpackV1 implementation (limitation)
     internal size_t WindowSize { get; private set; }
 
     internal byte[] R4Salt { get; private set; }
-
+    internal Rar5CryptoInfo Rar5CryptoInfo { get; private set; }
     private byte HostOs { get; set; }
     internal uint FileAttributes { get; private set; }
     internal long CompressedSize { get; private set; }
@@ -450,8 +471,7 @@ internal class FileHeader : RarHeader
 
     public bool IsDirectory => HasFlag(IsRar5 ? FileFlagsV5.DIRECTORY : FileFlagsV4.DIRECTORY);
 
-    private bool isEncryptedRar5 = false;
-    public bool IsEncrypted => IsRar5 ? isEncryptedRar5 : HasFlag(FileFlagsV4.PASSWORD);
+    public bool IsEncrypted => IsRar5 ? Rar5CryptoInfo != null : HasFlag(FileFlagsV4.PASSWORD);
 
     internal DateTime? FileLastModifiedTime { get; private set; }
 

src/SharpCompress/Common/Rar/Headers/Flags.cs

@@ -50,6 +50,17 @@ internal static class EncryptionFlagsV5
     public const uint FHEXTRA_CRYPT_HASHMAC = 0x02;
 }
 
+internal static class EncryptionConstV5
+{
+    public const int VERSION = 0;
+    public const uint CRYPT5_KDF_LG2_COUNT_MAX = 0x24;
+    public const int SIZE_SALT30 = 0x08;
+    public const int SIZE_SALT50 = 0x10;
+    public const int SIZE_INITV = 0x10;
+    public const int SIZE_PSWCHECK = 0x08;
+    public const int SIZE_PSWCHECK_CSUM = 0x04;
+}
+
 internal static class HeaderFlagsV5
 {
     public const ushort HAS_EXTRA = 0x0001;
@@ -146,3 +157,17 @@ internal static class EndArchiveFlagsV5
 {
     public const ushort HAS_NEXT_VOLUME = 0x0001;
 }
+
+internal static class RedirTypeV5
+{
+    public const byte UNIX_SYMLINK = 0x0001;
+    public const byte WIN_SYMLINK = 0x0002;
+    public const byte WIN_JUNCTION = 0x0003;
+    public const byte HARD_LINK = 0x0004;
+    public const byte FILE_COPY = 0x0005;
+}
+
+internal static class RedirFlagV5
+{
+    public const byte DIRECTORY = 0x0001;
+}

src/SharpCompress/Common/Rar/Headers/RarHeader.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using SharpCompress.IO;
 

src/SharpCompress/Common/Rar/Headers/RarHeaderFactory.cs

@@ -1,5 +1,7 @@
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
+using SharpCompress.Common.Rar;
 using SharpCompress.IO;
 using SharpCompress.Readers;
 
@@ -9,6 +11,8 @@ public class RarHeaderFactory
 {
     private bool _isRar5;
 
+    private Rar5CryptoInfo? _cryptInfo;
+
     public RarHeaderFactory(StreamingMode mode, ReaderOptions options)
     {
         StreamingMode = mode;
@@ -53,7 +57,19 @@ public class RarHeaderFactory
                     "Encrypted Rar archive has no password specified."
                 );
             }
-            reader = new RarCryptoBinaryReader(stream, Options.Password);
+
+            if (_isRar5 && _cryptInfo != null)
+            {
+                _cryptInfo.ReadInitV(new MarkingBinaryReader(stream));
+                var _headerKey = new CryptKey5(Options.Password!, _cryptInfo);
+
+                reader = new RarCryptoBinaryReader(stream, _headerKey, _cryptInfo.Salt);
+            }
+            else
+            {
+                var key = new CryptKey3(Options.Password);
+                reader = new RarCryptoBinaryReader(stream, key);
+            }
         }
 
         var header = RarHeader.TryReadBase(reader, _isRar5, Options.ArchiveEncoding);
@@ -105,7 +121,14 @@ public class RarHeaderFactory
             case HeaderCodeV.RAR5_SERVICE_HEADER:
             {
                 var fh = new FileHeader(header, reader, HeaderType.Service);
-                SkipData(fh, reader);
+                if (fh.FileName == "CMT")
+                {
+                    fh.PackedStream = new ReadOnlySubStream(reader.BaseStream, fh.CompressedSize);
+                }
+                else
+                {
+                    SkipData(fh, reader);
+                }
                 return fh;
             }
 
@@ -133,7 +156,7 @@ public class RarHeaderFactory
 
                         {
                             var ms = new ReadOnlySubStream(reader.BaseStream, fh.CompressedSize);
-                            if (fh.R4Salt is null)
+                            if (fh.R4Salt is null && fh.Rar5CryptoInfo is null)
                             {
                                 fh.PackedStream = ms;
                             }
@@ -141,8 +164,10 @@ public class RarHeaderFactory
                             {
                                 fh.PackedStream = new RarCryptoWrapper(
                                     ms,
-                                    Options.Password!,
-                                    fh.R4Salt
+                                    fh.R4Salt is null ? fh.Rar5CryptoInfo.Salt : fh.R4Salt,
+                                    fh.R4Salt is null
+                                        ? new CryptKey5(Options.Password!, fh.Rar5CryptoInfo)
+                                        : new CryptKey3(Options.Password!)
                                 );
                             }
                         }
@@ -161,9 +186,11 @@ public class RarHeaderFactory
             }
             case HeaderCodeV.RAR5_ARCHIVE_ENCRYPTION_HEADER:
             {
-                var ch = new ArchiveCryptHeader(header, reader);
+                var cryptoHeader = new ArchiveCryptHeader(header, reader);
                 IsEncrypted = true;
-                return ch;
+                _cryptInfo = cryptoHeader.CryptInfo;
+
+                return cryptoHeader;
             }
             default:
             {

src/SharpCompress/Common/Rar/ICryptKey.cs

@@ -0,0 +1,8 @@
+using System.Security.Cryptography;
+
+namespace SharpCompress.Common.Rar;
+
+internal interface ICryptKey
+{
+    ICryptoTransform Transformer(byte[] salt);
+}

src/SharpCompress/Common/Rar/Rar5CryptoInfo.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Security.Cryptography;
+using SharpCompress.Common.Rar.Headers;
+using SharpCompress.IO;
+
+namespace SharpCompress.Common.Rar;
+
+internal class Rar5CryptoInfo
+{
+    public Rar5CryptoInfo() { }
+
+    public Rar5CryptoInfo(MarkingBinaryReader reader, bool readInitV)
+    {
+        var cryptVersion = reader.ReadRarVIntUInt32();
+        if (cryptVersion > EncryptionConstV5.VERSION)
+        {
+            throw new CryptographicException($"Unsupported crypto version of {cryptVersion}");
+        }
+        var encryptionFlags = reader.ReadRarVIntUInt32();
+        UsePswCheck = FlagUtility.HasFlag(encryptionFlags, EncryptionFlagsV5.CHFL_CRYPT_PSWCHECK);
+        LG2Count = reader.ReadRarVIntByte(1);
+
+        if (LG2Count > EncryptionConstV5.CRYPT5_KDF_LG2_COUNT_MAX)
+        {
+            throw new CryptographicException($"Unsupported LG2 count of {LG2Count}.");
+        }
+
+        Salt = reader.ReadBytes(EncryptionConstV5.SIZE_SALT50);
+
+        if (readInitV) // File header needs to read IV here
+        {
+            ReadInitV(reader);
+        }
+
+        if (UsePswCheck)
+        {
+            PswCheck = reader.ReadBytes(EncryptionConstV5.SIZE_PSWCHECK);
+            var _pswCheckCsm = reader.ReadBytes(EncryptionConstV5.SIZE_PSWCHECK_CSUM);
+
+            var sha = SHA256.Create();
+            UsePswCheck = sha.ComputeHash(PswCheck).AsSpan().StartsWith(_pswCheckCsm.AsSpan());
+        }
+    }
+
+    public void ReadInitV(MarkingBinaryReader reader) =>
+        InitV = reader.ReadBytes(EncryptionConstV5.SIZE_INITV);
+
+    public bool UsePswCheck = false;
+
+    public int LG2Count = 0;
+
+    public byte[] InitV = { };
+
+    public byte[] Salt = { };
+
+    public byte[] PswCheck = { };
+}

src/SharpCompress/Common/Rar/RarCryptoBinaryReader.cs

@@ -1,29 +1,29 @@
-using System.Collections.Generic;
+#nullable disable
+
+using System.Collections.Generic;
 using System.IO;
+using SharpCompress.Common.Rar.Headers;
+using SharpCompress.Crypto;
 
 namespace SharpCompress.Common.Rar;
 
 internal sealed class RarCryptoBinaryReader : RarCrcBinaryReader
 {
-    private RarRijndael _rijndael;
-    private byte[] _salt;
-    private readonly string _password;
-    private readonly Queue<byte> _data = new Queue<byte>();
+    private BlockTransformer _rijndael;
+    private readonly Queue<byte> _data = new();
     private long _readCount;
 
-    public RarCryptoBinaryReader(Stream stream, string password)
+    public RarCryptoBinaryReader(Stream stream, ICryptKey cryptKey)
         : base(stream)
     {
-        _password = password;
-
-        // coderb: not sure why this was being done at this logical point
-        //SkipQueue();
-        var salt = ReadBytes(8);
-
-        _salt = salt;
-        _rijndael = RarRijndael.InitializeFrom(_password, salt);
+        var salt = base.ReadBytes(EncryptionConstV5.SIZE_SALT30);
+        _readCount += EncryptionConstV5.SIZE_SALT30;
+        _rijndael = new BlockTransformer(cryptKey.Transformer(salt));
     }
 
+    public RarCryptoBinaryReader(Stream stream, ICryptKey cryptKey, byte[] salt)
+        : base(stream) => _rijndael = new BlockTransformer(cryptKey.Transformer(salt));
+
     // track read count ourselves rather than using the underlying stream since we buffer
     public override long CurrentReadByteCount
     {
@@ -36,29 +36,9 @@ internal sealed class RarCryptoBinaryReader : RarCrcBinaryReader
 
     public override void Mark() => _readCount = 0;
 
-    private bool UseEncryption => _salt != null;
+    public override byte ReadByte() => ReadAndDecryptBytes(1)[0];
 
-    public override byte ReadByte()
-    {
-        if (UseEncryption)
-        {
-            return ReadAndDecryptBytes(1)[0];
-        }
-
-        _readCount++;
-        return base.ReadByte();
-    }
-
-    public override byte[] ReadBytes(int count)
-    {
-        if (UseEncryption)
-        {
-            return ReadAndDecryptBytes(count);
-        }
-
-        _readCount += count;
-        return base.ReadBytes(count);
-    }
+    public override byte[] ReadBytes(int count) => ReadAndDecryptBytes(count);
 
     private byte[] ReadAndDecryptBytes(int count)
     {

src/SharpCompress/Common/Rar/RarCryptoWrapper.cs

@@ -1,37 +1,30 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using SharpCompress.Crypto;
 
 namespace SharpCompress.Common.Rar;
 
 internal sealed class RarCryptoWrapper : Stream
 {
     private readonly Stream _actualStream;
-    private readonly byte[] _salt;
-    private RarRijndael _rijndael;
-    private readonly Queue<byte> _data = new Queue<byte>();
+    private BlockTransformer _rijndael;
+    private readonly Queue<byte> _data = new();
 
-    public RarCryptoWrapper(Stream actualStream, string password, byte[] salt)
+    public RarCryptoWrapper(Stream actualStream, byte[] salt, ICryptKey key)
     {
         _actualStream = actualStream;
-        _salt = salt;
-        _rijndael = RarRijndael.InitializeFrom(password ?? "", salt);
+        _rijndael = new BlockTransformer(key.Transformer(salt));
     }
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
 
     public override void SetLength(long value) => throw new NotSupportedException();
 
-    public override int Read(byte[] buffer, int offset, int count)
-    {
-        if (_salt is null)
-        {
-            return _actualStream.Read(buffer, offset, count);
-        }
-        return ReadAndDecrypt(buffer, offset, count);
-    }
+    public override int Read(byte[] buffer, int offset, int count) =>
+        ReadAndDecrypt(buffer, offset, count);
 
     public int ReadAndDecrypt(byte[] buffer, int offset, int count)
     {
@@ -41,7 +34,7 @@ internal sealed class RarCryptoWrapper : Stream
         if (sizeToRead > 0)
         {
             var alignedSize = sizeToRead + ((~sizeToRead + 1) & 0xf);
-            Span<byte> cipherText = stackalloc byte[RarRijndael.CRYPTO_BLOCK_SIZE];
+            Span<byte> cipherText = stackalloc byte[16];
             for (var i = 0; i < alignedSize / 16; i++)
             {
                 //long ax = System.currentTimeMillis();

src/SharpCompress/Common/Rar/RarEntry.cs

@@ -20,7 +20,7 @@ public abstract class RarEntry : Entry
     /// <summary>
     /// The File's 32 bit CRC Hash
     /// </summary>
-    public override long Crc => FileHeader.FileCrc;
+    public override long Crc => BitConverter.ToUInt32(FileHeader.FileCrc, 0);
 
     /// <summary>
     /// The path of the file internal to the Rar Archive.
@@ -55,12 +55,21 @@ public abstract class RarEntry : Entry
     public override bool IsEncrypted => FileHeader.IsEncrypted;
 
     /// <summary>
-    /// Entry is password protected and encrypted and cannot be extracted.
+    /// Entry Windows file attributes
+    /// </summary>
+    public override int? Attrib => (int)FileHeader.FileAttributes;
+
+    /// <summary>
+    /// Entry is a directory
     /// </summary>
     public override bool IsDirectory => FileHeader.IsDirectory;
 
     public override bool IsSplitAfter => FileHeader.IsSplitAfter;
 
+    public bool IsRedir => FileHeader.IsRedir;
+
+    public string RedirTargetName => FileHeader.RedirTargetName;
+
     public override string ToString() =>
         string.Format(
             "Entry Path: {0} Compressed Size: {1} Uncompressed Size: {2} CRC: {3}",

src/SharpCompress/Common/Rar/RarRijndael.cs

@@ -1,114 +0,0 @@
-#nullable disable
-
-using System;
-using System.Security.Cryptography;
-using System.Text;
-using SharpCompress.Crypto;
-
-namespace SharpCompress.Common.Rar;
-
-internal class RarRijndael : IDisposable
-{
-    internal const int CRYPTO_BLOCK_SIZE = 16;
-
-    private readonly string _password;
-    private readonly byte[] _salt;
-    private byte[] _aesInitializationVector;
-    private RijndaelEngine _rijndael;
-
-    private RarRijndael(string password, byte[] salt)
-    {
-        _password = password;
-        _salt = salt;
-    }
-
-    private void Initialize()
-    {
-        _rijndael = new RijndaelEngine();
-        _aesInitializationVector = new byte[CRYPTO_BLOCK_SIZE];
-        var rawLength = 2 * _password.Length;
-        var rawPassword = new byte[rawLength + 8];
-        var passwordBytes = Encoding.UTF8.GetBytes(_password);
-        for (var i = 0; i < _password.Length; i++)
-        {
-            rawPassword[i * 2] = passwordBytes[i];
-            rawPassword[(i * 2) + 1] = 0;
-        }
-        for (var i = 0; i < _salt.Length; i++)
-        {
-            rawPassword[i + rawLength] = _salt[i];
-        }
-
-        const int noOfRounds = (1 << 18);
-        const int iblock = 3;
-        byte[] digest;
-        var data = new byte[(rawPassword.Length + iblock) * noOfRounds];
-
-        //TODO slow code below, find ways to optimize
-        for (var i = 0; i < noOfRounds; i++)
-        {
-            rawPassword.CopyTo(data, i * (rawPassword.Length + iblock));
-
-            data[(i * (rawPassword.Length + iblock)) + rawPassword.Length + 0] = (byte)i;
-            data[(i * (rawPassword.Length + iblock)) + rawPassword.Length + 1] = (byte)(i >> 8);
-            data[(i * (rawPassword.Length + iblock)) + rawPassword.Length + 2] = (byte)(
-                i >> CRYPTO_BLOCK_SIZE
-            );
-
-            if (i % (noOfRounds / CRYPTO_BLOCK_SIZE) == 0)
-            {
-                digest = SHA1.Create()
-                    .ComputeHash(data, 0, (i + 1) * (rawPassword.Length + iblock));
-                _aesInitializationVector[i / (noOfRounds / CRYPTO_BLOCK_SIZE)] = digest[19];
-            }
-        }
-        digest = SHA1.Create().ComputeHash(data);
-        //slow code ends
-
-        var aesKey = new byte[CRYPTO_BLOCK_SIZE];
-        for (var i = 0; i < 4; i++)
-        {
-            for (var j = 0; j < 4; j++)
-            {
-                aesKey[(i * 4) + j] = (byte)(
-                    (
-                        ((digest[i * 4] * 0x1000000) & 0xff000000)
-                        | (uint)((digest[(i * 4) + 1] * 0x10000) & 0xff0000)
-                        | (uint)((digest[(i * 4) + 2] * 0x100) & 0xff00)
-                        | (uint)(digest[(i * 4) + 3] & 0xff)
-                    ) >> (j * 8)
-                );
-            }
-        }
-
-        _rijndael.Init(false, new KeyParameter(aesKey));
-    }
-
-    public static RarRijndael InitializeFrom(string password, byte[] salt)
-    {
-        var rijndael = new RarRijndael(password, salt);
-        rijndael.Initialize();
-        return rijndael;
-    }
-
-    public byte[] ProcessBlock(ReadOnlySpan<byte> cipherText)
-    {
-        Span<byte> plainText = stackalloc byte[CRYPTO_BLOCK_SIZE]; // 16 bytes
-        var decryptedBytes = new byte[CRYPTO_BLOCK_SIZE];
-        _rijndael.ProcessBlock(cipherText, plainText);
-
-        for (var j = 0; j < CRYPTO_BLOCK_SIZE; j++)
-        {
-            decryptedBytes[j] = (byte)(plainText[j] ^ _aesInitializationVector[j % 16]); //32:114, 33:101
-        }
-
-        for (var j = 0; j < _aesInitializationVector.Length; j++)
-        {
-            _aesInitializationVector[j] = cipherText[j];
-        }
-
-        return decryptedBytes;
-    }
-
-    public void Dispose() { }
-}

src/SharpCompress/Common/Rar/RarVolume.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text;
 using SharpCompress.Common.Rar.Headers;
 using SharpCompress.IO;
 using SharpCompress.Readers;
@@ -70,11 +71,7 @@ public abstract class RarVolume : Volume
                             var part = CreateFilePart(lastMarkHeader!, fh);
                             var buffer = new byte[fh.CompressedSize];
                             part.GetCompressedStream().Read(buffer, 0, buffer.Length);
-                            Comment = System.Text.Encoding.UTF8.GetString(
-                                buffer,
-                                0,
-                                buffer.Length - 1
-                            );
+                            Comment = Encoding.UTF8.GetString(buffer, 0, buffer.Length - 1);
                         }
                     }
                     break;

src/SharpCompress/Common/ReaderCancelledException.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace SharpCompress.Common;
+
+public class ReaderCancelledException : Exception
+{
+    public ReaderCancelledException(string message)
+        : base(message) { }
+
+    public ReaderCancelledException(string message, Exception inner)
+        : base(message, inner) { }
+}

src/SharpCompress/Common/SevenZip/ArchiveDatabase.cs

@@ -15,15 +15,15 @@ internal class ArchiveDatabase
     internal long _startPositionAfterHeader;
     internal long _dataStartPosition;
 
-    internal List<long> _packSizes = new List<long>();
-    internal List<uint?> _packCrCs = new List<uint?>();
-    internal List<CFolder> _folders = new List<CFolder>();
+    internal List<long> _packSizes = new();
+    internal List<uint?> _packCrCs = new();
+    internal List<CFolder> _folders = new();
     internal List<int> _numUnpackStreamsVector;
-    internal List<CFileItem> _files = new List<CFileItem>();
+    internal List<CFileItem> _files = new();
 
-    internal List<long> _packStreamStartPositions = new List<long>();
-    internal List<int> _folderStartFileIndex = new List<int>();
-    internal List<int> _fileIndexToFolderIndexMap = new List<int>();
+    internal List<long> _packStreamStartPositions = new();
+    internal List<int> _folderStartFileIndex = new();
+    internal List<int> _fileIndexToFolderIndexMap = new();
 
     internal IPasswordProvider PasswordProvider { get; }
 

src/SharpCompress/Common/SevenZip/ArchiveReader.cs

@@ -14,13 +14,13 @@ namespace SharpCompress.Common.SevenZip;
 internal class ArchiveReader
 {
     internal Stream _stream;
-    internal Stack<DataReader> _readerStack = new Stack<DataReader>();
+    internal Stack<DataReader> _readerStack = new();
     internal DataReader _currentReader;
     internal long _streamOrigin;
     internal long _streamEnding;
     internal byte[] _header;
 
-    private readonly Dictionary<int, Stream> _cachedStreams = new Dictionary<int, Stream>();
+    private readonly Dictionary<int, Stream> _cachedStreams = new();
 
     internal void AddByteStream(byte[] buffer, int offset, int length)
     {
@@ -1359,7 +1359,7 @@ internal class ArchiveReader
     {
         internal int _fileIndex;
         internal int _folderIndex;
-        internal List<bool> _extractStatuses = new List<bool>();
+        internal List<bool> _extractStatuses = new();
 
         internal CExtractFolderInfo(int fileIndex, int folderIndex)
         {
@@ -1393,7 +1393,7 @@ internal class ArchiveReader
 
         public override bool CanWrite => false;
 
-        public override void Flush() => throw new NotSupportedException();
+        public override void Flush() { }
 
         public override long Length => throw new NotSupportedException();
 

src/SharpCompress/Common/SevenZip/CFolder.cs

@@ -6,11 +6,11 @@ namespace SharpCompress.Common.SevenZip;
 
 internal class CFolder
 {
-    internal List<CCoderInfo> _coders = new List<CCoderInfo>();
-    internal List<CBindPair> _bindPairs = new List<CBindPair>();
-    internal List<int> _packStreams = new List<int>();
+    internal List<CCoderInfo> _coders = new();
+    internal List<CBindPair> _bindPairs = new();
+    internal List<int> _packStreams = new();
     internal int _firstPackStreamId;
-    internal List<long> _unpackSizes = new List<long>();
+    internal List<long> _unpackSizes = new();
     internal uint? _unpackCrc;
 
     internal bool UnpackCrcDefined => _unpackCrc != null;

src/SharpCompress/Common/SevenZip/CMethodId.cs

@@ -7,10 +7,10 @@ internal readonly struct CMethodId
     public const ulong K_LZMA2_ID = 0x21;
     public const ulong K_AES_ID = 0x06F10701;
 
-    public static readonly CMethodId K_COPY = new CMethodId(K_COPY_ID);
-    public static readonly CMethodId K_LZMA = new CMethodId(K_LZMA_ID);
-    public static readonly CMethodId K_LZMA2 = new CMethodId(K_LZMA2_ID);
-    public static readonly CMethodId K_AES = new CMethodId(K_AES_ID);
+    public static readonly CMethodId K_COPY = new(K_COPY_ID);
+    public static readonly CMethodId K_LZMA = new(K_LZMA_ID);
+    public static readonly CMethodId K_LZMA2 = new(K_LZMA2_ID);
+    public static readonly CMethodId K_AES = new(K_AES_ID);
 
     public readonly ulong _id;
 

src/SharpCompress/Common/SevenZip/SevenZipFilePart.cs

@@ -75,6 +75,9 @@ internal class SevenZipFilePart : FilePart
 
     internal CompressionType GetCompression()
     {
+        if (Header.IsDir)
+            return CompressionType.None;
+
         var coder = Folder!._coders.First();
         switch (coder._methodId._id)
         {
@@ -97,5 +100,7 @@ internal class SevenZipFilePart : FilePart
     }
 
     internal bool IsEncrypted =>
-        Folder!._coders.FindIndex(c => c._methodId._id == CMethodId.K_AES_ID) != -1;
+        Header.IsDir
+            ? false
+            : Folder!._coders.FindIndex(c => c._methodId._id == CMethodId.K_AES_ID) != -1;
 }

src/SharpCompress/Common/Tar/Headers/TarHeader.cs

@@ -1,4 +1,4 @@
-#nullable disable
+#nullable disable
 
 using System;
 using System.Buffers.Binary;
@@ -9,7 +9,7 @@ namespace SharpCompress.Common.Tar.Headers;
 
 internal sealed class TarHeader
 {
-    internal static readonly DateTime EPOCH = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+    internal static readonly DateTime EPOCH = new(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
     public TarHeader(ArchiveEncoding archiveEncoding) => ArchiveEncoding = archiveEncoding;
 
@@ -132,8 +132,8 @@ internal sealed class TarHeader
             Mode |= 0b1_000_000_000;
         }
 
-        UserId = ReadAsciiInt64Base8(buffer, 108, 7);
-        GroupId = ReadAsciiInt64Base8(buffer, 116, 7);
+        UserId = ReadAsciiInt64Base8oldGnu(buffer, 108, 7);
+        GroupId = ReadAsciiInt64Base8oldGnu(buffer, 116, 7);
         var unixTimeStamp = ReadAsciiInt64Base8(buffer, 136, 11);
         LastModifiedTime = EPOCH.AddSeconds(unixTimeStamp).ToLocalTime();
 
@@ -249,6 +249,24 @@ internal sealed class TarHeader
         return Convert.ToInt64(s, 8);
     }
 
+    private static long ReadAsciiInt64Base8oldGnu(byte[] buffer, int offset, int count)
+    {
+        if (buffer[offset] == 0x80 && buffer[offset + 1] == 0x00)
+        {
+            return buffer[offset + 4] << 24
+                | buffer[offset + 5] << 16
+                | buffer[offset + 6] << 8
+                | buffer[offset + 7];
+        }
+        var s = Encoding.UTF8.GetString(buffer, offset, count).TrimNulls();
+
+        if (string.IsNullOrEmpty(s))
+        {
+            return 0;
+        }
+        return Convert.ToInt64(s, 8);
+    }
+
     private static long ReadAsciiInt64(byte[] buffer, int offset, int count)
     {
         var s = Encoding.UTF8.GetString(buffer, offset, count).TrimNulls();

src/SharpCompress/Common/Tar/TarReadOnlySubStream.cs

@@ -1,6 +1,6 @@
-using SharpCompress.IO;
 using System;
 using System.IO;
+using SharpCompress.IO;
 
 namespace SharpCompress.Common.Tar;
 
@@ -47,7 +47,7 @@ internal class TarReadOnlySubStream : NonDisposingStream
 
     public override bool CanWrite => false;
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override long Length => throw new NotSupportedException();
 
@@ -63,7 +63,7 @@ internal class TarReadOnlySubStream : NonDisposingStream
         {
             count = (int)BytesLeftToRead;
         }
-        int read = Stream.Read(buffer, offset, count);
+        var read = Stream.Read(buffer, offset, count);
         if (read > 0)
         {
             BytesLeftToRead -= read;
@@ -78,7 +78,7 @@ internal class TarReadOnlySubStream : NonDisposingStream
         {
             return -1;
         }
-        int value = Stream.ReadByte();
+        var value = Stream.ReadByte();
         if (value != -1)
         {
             --BytesLeftToRead;

src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs

@@ -14,8 +14,8 @@ internal class DirectoryEntryHeader : ZipFileEntry
         VersionNeededToExtract = reader.ReadUInt16();
         Flags = (HeaderFlags)reader.ReadUInt16();
         CompressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
-        LastModifiedTime = reader.ReadUInt16();
-        LastModifiedDate = reader.ReadUInt16();
+        OriginalLastModifiedTime = LastModifiedTime = reader.ReadUInt16();
+        OriginalLastModifiedDate = LastModifiedDate = reader.ReadUInt16();
         Crc = reader.ReadUInt32();
         CompressedSize = reader.ReadUInt32();
         UncompressedSize = reader.ReadUInt32();
@@ -52,8 +52,8 @@ internal class DirectoryEntryHeader : ZipFileEntry
 
         LoadExtra(extra);
 
-        var unicodePathExtra = Extra.FirstOrDefault(
-            u => u.Type == ExtraDataType.UnicodePathExtraField
+        var unicodePathExtra = Extra.FirstOrDefault(u =>
+            u.Type == ExtraDataType.UnicodePathExtraField
         );
         if (unicodePathExtra != null && ArchiveEncoding.Forced == null)
         {
@@ -85,6 +85,36 @@ internal class DirectoryEntryHeader : ZipFileEntry
                 RelativeOffsetOfEntryHeader = zip64ExtraData.RelativeOffsetOfEntryHeader;
             }
         }
+
+        var unixTimeExtra = Extra.FirstOrDefault(u => u.Type == ExtraDataType.UnixTimeExtraField);
+
+        if (unixTimeExtra is not null)
+        {
+            // Tuple order is last modified time, last access time, and creation time.
+            var unixTimeTuple = ((UnixTimeExtraField)unixTimeExtra).UnicodeTimes;
+
+            if (unixTimeTuple.Item1.HasValue)
+            {
+                var dosTime = Utility.DateTimeToDosTime(unixTimeTuple.Item1.Value);
+
+                LastModifiedDate = (ushort)(dosTime >> 16);
+                LastModifiedTime = (ushort)(dosTime & 0x0FFFF);
+            }
+            else if (unixTimeTuple.Item2.HasValue)
+            {
+                var dosTime = Utility.DateTimeToDosTime(unixTimeTuple.Item2.Value);
+
+                LastModifiedDate = (ushort)(dosTime >> 16);
+                LastModifiedTime = (ushort)(dosTime & 0x0FFFF);
+            }
+            else if (unixTimeTuple.Item3.HasValue)
+            {
+                var dosTime = Utility.DateTimeToDosTime(unixTimeTuple.Item3.Value);
+
+                LastModifiedDate = (ushort)(dosTime >> 16);
+                LastModifiedTime = (ushort)(dosTime & 0x0FFFF);
+            }
+        }
     }
 
     internal ushort Version { get; private set; }

src/SharpCompress/Common/Zip/Headers/LocalEntryHeader.cs

@@ -13,8 +13,8 @@ internal class LocalEntryHeader : ZipFileEntry
         Version = reader.ReadUInt16();
         Flags = (HeaderFlags)reader.ReadUInt16();
         CompressionMethod = (ZipCompressionMethod)reader.ReadUInt16();
-        LastModifiedTime = reader.ReadUInt16();
-        LastModifiedDate = reader.ReadUInt16();
+        OriginalLastModifiedTime = LastModifiedTime = reader.ReadUInt16();
+        OriginalLastModifiedDate = LastModifiedDate = reader.ReadUInt16();
         Crc = reader.ReadUInt32();
         CompressedSize = reader.ReadUInt32();
         UncompressedSize = reader.ReadUInt32();
@@ -42,8 +42,8 @@ internal class LocalEntryHeader : ZipFileEntry
 
         LoadExtra(extra);
 
-        var unicodePathExtra = Extra.FirstOrDefault(
-            u => u.Type == ExtraDataType.UnicodePathExtraField
+        var unicodePathExtra = Extra.FirstOrDefault(u =>
+            u.Type == ExtraDataType.UnicodePathExtraField
         );
         if (unicodePathExtra != null && ArchiveEncoding.Forced == null)
         {
@@ -64,6 +64,36 @@ internal class LocalEntryHeader : ZipFileEntry
                 UncompressedSize = zip64ExtraData.UncompressedSize;
             }
         }
+
+        var unixTimeExtra = Extra.FirstOrDefault(u => u.Type == ExtraDataType.UnixTimeExtraField);
+
+        if (unixTimeExtra is not null)
+        {
+            // Tuple order is last modified time, last access time, and creation time.
+            var unixTimeTuple = ((UnixTimeExtraField)unixTimeExtra).UnicodeTimes;
+
+            if (unixTimeTuple.Item1.HasValue)
+            {
+                var dosTime = Utility.DateTimeToDosTime(unixTimeTuple.Item1.Value);
+
+                LastModifiedDate = (ushort)(dosTime >> 16);
+                LastModifiedTime = (ushort)(dosTime & 0x0FFFF);
+            }
+            else if (unixTimeTuple.Item2.HasValue)
+            {
+                var dosTime = Utility.DateTimeToDosTime(unixTimeTuple.Item2.Value);
+
+                LastModifiedDate = (ushort)(dosTime >> 16);
+                LastModifiedTime = (ushort)(dosTime & 0x0FFFF);
+            }
+            else if (unixTimeTuple.Item3.HasValue)
+            {
+                var dosTime = Utility.DateTimeToDosTime(unixTimeTuple.Item3.Value);
+
+                LastModifiedDate = (ushort)(dosTime >> 16);
+                LastModifiedTime = (ushort)(dosTime & 0x0FFFF);
+            }
+        }
     }
 
     internal ushort Version { get; private set; }

src/SharpCompress/Common/Zip/Headers/LocalEntryHeaderExtraFactory.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Buffers.Binary;
 using System.Text;
 
@@ -13,7 +13,8 @@ internal enum ExtraDataType : ushort
     // Third Party Mappings
     // -Info-ZIP Unicode Path Extra Field
     UnicodePathExtraField = 0x7075,
-    Zip64ExtendedInformationExtraField = 0x0001
+    Zip64ExtendedInformationExtraField = 0x0001,
+    UnixTimeExtraField = 0x5455
 }
 
 internal class ExtraData
@@ -145,6 +146,84 @@ internal sealed class Zip64ExtendedInformationExtraField : ExtraData
     public uint VolumeNumber { get; private set; }
 }
 
+internal sealed class UnixTimeExtraField : ExtraData
+{
+    public UnixTimeExtraField(ExtraDataType type, ushort length, byte[] dataBytes)
+        : base(type, length, dataBytes) { }
+
+    /// <summary>
+    /// The unix modified time, last access time, and creation time, if set.
+    /// </summary>
+    /// <remarks>Must return Tuple explicitly due to net462 support.</remarks>
+    internal Tuple<DateTime?, DateTime?, DateTime?> UnicodeTimes
+    {
+        get
+        {
+            // There has to be at least 5 byte for there to be a timestamp.
+            // 1 byte for flags and 4 bytes for a timestamp.
+            if (DataBytes is null || DataBytes.Length < 5)
+            {
+                return Tuple.Create<DateTime?, DateTime?, DateTime?>(null, null, null);
+            }
+
+            var flags = DataBytes[0];
+            var isModifiedTimeSpecified = (flags & 0x01) == 1;
+            var isLastAccessTimeSpecified = (flags & 0x02) == 1;
+            var isCreationTimeSpecified = (flags & 0x04) == 1;
+            var currentIndex = 1;
+            DateTime? modifiedTime = null;
+            DateTime? lastAccessTime = null;
+            DateTime? creationTime = null;
+
+            if (isModifiedTimeSpecified)
+            {
+                var modifiedEpochTime = BinaryPrimitives.ReadInt32LittleEndian(
+                    DataBytes.AsSpan(currentIndex, 4)
+                );
+
+                currentIndex += 4;
+                modifiedTime = DateTimeOffset.FromUnixTimeSeconds(modifiedEpochTime).UtcDateTime;
+            }
+
+            if (isLastAccessTimeSpecified)
+            {
+                if (currentIndex + 4 > DataBytes.Length)
+                {
+                    throw new ArchiveException("Invalid UnicodeExtraTime field");
+                }
+
+                var lastAccessEpochTime = BinaryPrimitives.ReadInt32LittleEndian(
+                    DataBytes.AsSpan(currentIndex, 4)
+                );
+
+                currentIndex += 4;
+                lastAccessTime = DateTimeOffset
+                    .FromUnixTimeSeconds(lastAccessEpochTime)
+                    .UtcDateTime;
+            }
+
+            if (isCreationTimeSpecified)
+            {
+                if (currentIndex + 4 > DataBytes.Length)
+                {
+                    throw new ArchiveException("Invalid UnicodeExtraTime field");
+                }
+
+                var creationTimeEpochTime = BinaryPrimitives.ReadInt32LittleEndian(
+                    DataBytes.AsSpan(currentIndex, 4)
+                );
+
+                currentIndex += 4;
+                creationTime = DateTimeOffset
+                    .FromUnixTimeSeconds(creationTimeEpochTime)
+                    .UtcDateTime;
+            }
+
+            return Tuple.Create(modifiedTime, lastAccessTime, creationTime);
+        }
+    }
+}
+
 internal static class LocalEntryHeaderExtraFactory
 {
     internal static ExtraData Create(ExtraDataType type, ushort length, byte[] extraData) =>
@@ -154,6 +233,7 @@ internal static class LocalEntryHeaderExtraFactory
                 => new ExtraUnicodePathExtraField(type, length, extraData),
             ExtraDataType.Zip64ExtendedInformationExtraField
                 => new Zip64ExtendedInformationExtraField(type, length, extraData),
+            ExtraDataType.UnixTimeExtraField => new UnixTimeExtraField(type, length, extraData),
             _ => new ExtraData(type, length, extraData)
         };
 }

src/SharpCompress/Common/Zip/Headers/ZipFileEntry.cs

@@ -67,8 +67,26 @@ internal abstract class ZipFileEntry : ZipHeader
 
     internal WinzipAesEncryptionData WinzipAesEncryptionData { get; set; }
 
+    /// <summary>
+    /// The last modified date as read from the Local or Central Directory header.
+    /// </summary>
+    internal ushort OriginalLastModifiedDate { get; set; }
+
+    /// <summary>
+    /// The last modified date from the UnixTimeExtraField, if present, or the
+    /// Local or Cental Directory header, if not.
+    /// </summary>
     internal ushort LastModifiedDate { get; set; }
 
+    /// <summary>
+    /// The last modified time as read from the Local or Central Directory header.
+    /// </summary>
+    internal ushort OriginalLastModifiedTime { get; set; }
+
+    /// <summary>
+    /// The last modified time from the UnixTimeExtraField, if present, or the
+    /// Local or Cental Directory header, if not.
+    /// </summary>
     internal ushort LastModifiedTime { get; set; }
 
     internal uint Crc { get; set; }

src/SharpCompress/Common/Zip/PkwareTraditionalCryptoStream.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 
 namespace SharpCompress.Common.Zip;
@@ -87,10 +87,7 @@ internal class PkwareTraditionalCryptoStream : Stream
         _stream.Write(encrypted, 0, encrypted.Length);
     }
 
-    public override void Flush()
-    {
-        //throw new NotSupportedException();
-    }
+    public override void Flush() { }
 
     public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
 

src/SharpCompress/Common/Zip/PkwareTraditionalEncryptionData.cs

@@ -6,7 +6,7 @@ namespace SharpCompress.Common.Zip;
 
 internal class PkwareTraditionalEncryptionData
 {
-    private static readonly CRC32 CRC32 = new CRC32();
+    private static readonly CRC32 CRC32 = new();
     private readonly uint[] _keys = { 0x12345678, 0x23456789, 0x34567890 };
     private readonly ArchiveEncoding _archiveEncoding;
 
@@ -39,7 +39,7 @@ internal class PkwareTraditionalEncryptionData
             {
                 throw new CryptographicException("The password did not match.");
             }
-            if (plainTextHeader[11] != (byte)((header.LastModifiedTime >> 8) & 0xff))
+            if (plainTextHeader[11] != (byte)((header.OriginalLastModifiedTime >> 8) & 0xff))
             {
                 throw new CryptographicException("The password did not match.");
             }

src/SharpCompress/Common/Zip/StreamingZipHeaderFactory.cs

@@ -15,10 +15,7 @@ internal class StreamingZipHeaderFactory : ZipHeaderFactory
         ArchiveEncoding archiveEncoding,
         IEnumerable<ZipEntry>? entries
     )
-        : base(StreamingMode.Streaming, password, archiveEncoding)
-    {
-        _entries = entries;
-    }
+        : base(StreamingMode.Streaming, password, archiveEncoding) => _entries = entries;
 
     internal IEnumerable<ZipHeader> ReadStreamHeader(Stream stream)
     {
@@ -97,13 +94,12 @@ internal class StreamingZipHeaderFactory : ZipHeaderFactory
             if (header.ZipHeaderType == ZipHeaderType.LocalEntry)
             {
                 var local_header = ((LocalEntryHeader)header);
-                var dir_header = _entries?.FirstOrDefault(
-                    entry =>
-                        entry.Key == local_header.Name
-                        && local_header.CompressedSize == 0
-                        && local_header.UncompressedSize == 0
-                        && local_header.Crc == 0
-                        && local_header.IsDirectory == false
+                var dir_header = _entries?.FirstOrDefault(entry =>
+                    entry.Key == local_header.Name
+                    && local_header.CompressedSize == 0
+                    && local_header.UncompressedSize == 0
+                    && local_header.Crc == 0
+                    && local_header.IsDirectory == false
                 );
 
                 if (dir_header != null)

src/SharpCompress/Common/Zip/WinzipAesCryptoStream.cs

@@ -73,7 +73,7 @@ internal class WinzipAesCryptoStream : Stream
         }
     }
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override int Read(byte[] buffer, int offset, int count)
     {

src/SharpCompress/Common/Zip/WinzipAesEncryptionData.cs

@@ -48,15 +48,15 @@ internal class WinzipAesEncryptionData
 
     private void Initialize()
     {
-#if NET7_0
+#if NETFRAMEWORK || NETSTANDARD2_0
+        var rfc2898 = new Rfc2898DeriveBytes(_password, _salt, RFC2898_ITERATIONS);
+#else
         var rfc2898 = new Rfc2898DeriveBytes(
             _password,
             _salt,
             RFC2898_ITERATIONS,
             HashAlgorithmName.SHA1
         );
-#else
-        var rfc2898 = new Rfc2898DeriveBytes(_password, _salt, RFC2898_ITERATIONS);
 #endif
 
         KeyBytes = rfc2898.GetBytes(KeySizeInBytes); // 16 or 24 or 32 ???

src/SharpCompress/Common/Zip/ZipCompressionMethod.cs

@@ -3,6 +3,7 @@ namespace SharpCompress.Common.Zip;
 internal enum ZipCompressionMethod
 {
     None = 0,
+    Shrink = 1,
     Deflate = 8,
     Deflate64 = 9,
     BZip2 = 12,

src/SharpCompress/Common/Zip/ZipEntry.cs

@@ -22,43 +22,18 @@ public class ZipEntry : Entry
         }
     }
 
-    public override CompressionType CompressionType
-    {
-        get
+    public override CompressionType CompressionType =>
+        _filePart.Header.CompressionMethod switch
         {
-            switch (_filePart.Header.CompressionMethod)
-            {
-                case ZipCompressionMethod.BZip2:
-                {
-                    return CompressionType.BZip2;
-                }
-                case ZipCompressionMethod.Deflate:
-                {
-                    return CompressionType.Deflate;
-                }
-                case ZipCompressionMethod.Deflate64:
-                {
-                    return CompressionType.Deflate64;
-                }
-                case ZipCompressionMethod.LZMA:
-                {
-                    return CompressionType.LZMA;
-                }
-                case ZipCompressionMethod.PPMd:
-                {
-                    return CompressionType.PPMd;
-                }
-                case ZipCompressionMethod.None:
-                {
-                    return CompressionType.None;
-                }
-                default:
-                {
-                    return CompressionType.Unknown;
-                }
-            }
-        }
-    }
+            ZipCompressionMethod.BZip2 => CompressionType.BZip2,
+            ZipCompressionMethod.Deflate => CompressionType.Deflate,
+            ZipCompressionMethod.Deflate64 => CompressionType.Deflate64,
+            ZipCompressionMethod.LZMA => CompressionType.LZMA,
+            ZipCompressionMethod.PPMd => CompressionType.PPMd,
+            ZipCompressionMethod.None => CompressionType.None,
+            ZipCompressionMethod.Shrink => CompressionType.Shrink,
+            _ => CompressionType.Unknown
+        };
 
     public override long Crc => _filePart.Header.Crc;
 

src/SharpCompress/Common/Zip/ZipFilePart.cs

@@ -9,6 +9,7 @@ using SharpCompress.Compressors.Deflate;
 using SharpCompress.Compressors.Deflate64;
 using SharpCompress.Compressors.LZMA;
 using SharpCompress.Compressors.PPMd;
+using SharpCompress.Compressors.Shrink;
 using SharpCompress.Compressors.Xz;
 using SharpCompress.IO;
 using ZstdSharp;
@@ -79,6 +80,15 @@ internal abstract class ZipFilePart : FilePart
 
                 return new DataDescriptorStream(stream);
             }
+            case ZipCompressionMethod.Shrink:
+            {
+                return new ShrinkStream(
+                    stream,
+                    CompressionMode.Decompress,
+                    Header.CompressedSize,
+                    Header.UncompressedSize
+                );
+            }
             case ZipCompressionMethod.Deflate:
             {
                 return new DeflateStream(stream, CompressionMode.Decompress);
@@ -192,6 +202,7 @@ internal abstract class ZipFilePart : FilePart
             switch (Header.CompressionMethod)
             {
                 case ZipCompressionMethod.None:
+                case ZipCompressionMethod.Shrink:
                 case ZipCompressionMethod.Deflate:
                 case ZipCompressionMethod.Deflate64:
                 case ZipCompressionMethod.BZip2:

src/SharpCompress/Common/Zip/ZipHeaderFactory.cs

@@ -142,8 +142,8 @@ internal class ZipHeaderFactory
 
             if (entryHeader.CompressionMethod == ZipCompressionMethod.WinzipAes)
             {
-                var data = entryHeader.Extra.SingleOrDefault(
-                    x => x.Type == ExtraDataType.WinZipAes
+                var data = entryHeader.Extra.SingleOrDefault(x =>
+                    x.Type == ExtraDataType.WinZipAes
                 );
                 if (data != null)
                 {

src/SharpCompress/Compressors/BZip2/CBZip2InputStream.cs

@@ -87,7 +87,7 @@ internal class CBZip2InputStream : Stream
 
     private int bsBuff;
     private int bsLive;
-    private readonly CRC mCrc = new CRC();
+    private readonly CRC mCrc = new();
 
     private readonly bool[] inUse = new bool[256];
     private int nInUse;

src/SharpCompress/Compressors/BZip2/CBZip2OutputStream.cs

@@ -284,7 +284,7 @@ internal sealed class CBZip2OutputStream : Stream
     private int bytesOut;
     private int bsBuff;
     private int bsLive;
-    private readonly CRC mCrc = new CRC();
+    private readonly CRC mCrc = new();
 
     private readonly bool[] inUse = new bool[256];
     private int nInUse;

src/SharpCompress/Compressors/Deflate/DeflateManager.cs

@@ -69,7 +69,6 @@
 // -----------------------------------------------------------------------
 
 using System;
-
 using SharpCompress.Algorithms;
 
 namespace SharpCompress.Compressors.Deflate;
@@ -343,9 +342,9 @@ internal sealed partial class DeflateManager
     private readonly short[] dyn_dtree; // distance tree
     private readonly short[] bl_tree; // Huffman tree for bit lengths
 
-    private readonly Tree treeLiterals = new Tree(); // desc for literal tree
-    private readonly Tree treeDistances = new Tree(); // desc for distance tree
-    private readonly Tree treeBitLengths = new Tree(); // desc for bit length tree
+    private readonly Tree treeLiterals = new(); // desc for literal tree
+    private readonly Tree treeDistances = new(); // desc for distance tree
+    private readonly Tree treeBitLengths = new(); // desc for bit length tree
 
     // number of codes at each bit length for an optimal tree
     private readonly short[] bl_count = new short[InternalConstants.MAX_BITS + 1];
@@ -1788,21 +1787,14 @@ internal sealed partial class DeflateManager
         return status == BUSY_STATE ? ZlibConstants.Z_DATA_ERROR : ZlibConstants.Z_OK;
     }
 
-    private void SetDeflater()
-    {
-        switch (config.Flavor)
+    private void SetDeflater() =>
+        DeflateFunction = config.Flavor switch
         {
-            case DeflateFlavor.Store:
-                DeflateFunction = DeflateNone;
-                break;
-            case DeflateFlavor.Fast:
-                DeflateFunction = DeflateFast;
-                break;
-            case DeflateFlavor.Slow:
-                DeflateFunction = DeflateSlow;
-                break;
-        }
-    }
+            DeflateFlavor.Store => DeflateNone,
+            DeflateFlavor.Fast => DeflateFast,
+            DeflateFlavor.Slow => DeflateSlow,
+            _ => DeflateFunction
+        };
 
     internal int SetParams(CompressionLevel level, CompressionStrategy strategy)
     {
@@ -1959,7 +1951,9 @@ internal sealed partial class DeflateManager
             // returning Z_STREAM_END instead of Z_BUFF_ERROR.
         }
         else if (
-            _codec.AvailableBytesIn == 0 && (int)flush <= old_flush && flush != FlushType.Finish
+            _codec.AvailableBytesIn == 0
+            && (int)flush <= old_flush
+            && flush != FlushType.Finish
         )
         {
             // workitem 8557

src/SharpCompress/Compressors/Deflate/DeflateStream.cs

@@ -366,9 +366,5 @@ public class DeflateStream : Stream
     #endregion
 
     public MemoryStream InputBuffer =>
-        new MemoryStream(
-            _baseStream._z.InputBuffer,
-            _baseStream._z.NextIn,
-            _baseStream._z.AvailableBytesIn
-        );
+        new(_baseStream._z.InputBuffer, _baseStream._z.NextIn, _baseStream._z.AvailableBytesIn);
 }

src/SharpCompress/Compressors/Deflate/GZipStream.cs

@@ -35,15 +35,7 @@ namespace SharpCompress.Compressors.Deflate;
 
 public class GZipStream : Stream
 {
-    internal static readonly DateTime UNIX_EPOCH = new DateTime(
-        1970,
-        1,
-        1,
-        0,
-        0,
-        0,
-        DateTimeKind.Utc
-    );
+    internal static readonly DateTime UNIX_EPOCH = new(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
     private string? _comment;
     private string? _fileName;

src/SharpCompress/Compressors/Deflate/Inflate.cs

@@ -64,7 +64,6 @@
 // -----------------------------------------------------------------------
 
 using System;
-
 using SharpCompress.Algorithms;
 
 namespace SharpCompress.Compressors.Deflate;
@@ -106,11 +105,11 @@ internal sealed class InflateBlocks
     internal int[] blens; // bit lengths of codes
     internal uint check; // check on output
     internal object checkfn; // check function
-    internal InflateCodes codes = new InflateCodes(); // if CODES, current state
+    internal InflateCodes codes = new(); // if CODES, current state
     internal int end; // one byte after sliding window
     internal int[] hufts; // single malloc for tree space
     internal int index; // index into blens (or border)
-    internal InfTree inftree = new InfTree();
+    internal InfTree inftree = new();
     internal int last; // true if this block is the last block
     internal int left; // if STORED, bytes left to copy
     private InflateBlockMode mode; // current inflate_block mode

src/SharpCompress/Compressors/Deflate/ZlibBaseStream.cs

@@ -30,8 +30,8 @@ using System;
 using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.IO;
-using SharpCompress.Common.Tar.Headers;
 using System.Text;
+using SharpCompress.Common.Tar.Headers;
 
 namespace SharpCompress.Compressors.Deflate;
 
@@ -102,7 +102,7 @@ internal class ZlibBaseStream : Stream
         {
             if (_z is null)
             {
-                bool wantRfc1950Header = (_flavor == ZlibStreamFlavor.ZLIB);
+                var wantRfc1950Header = (_flavor == ZlibStreamFlavor.ZLIB);
                 _z = new ZlibCodec();
                 if (_compressionMode == CompressionMode.Decompress)
                 {
@@ -147,13 +147,13 @@ internal class ZlibBaseStream : Stream
         z.InputBuffer = buffer;
         _z.NextIn = offset;
         _z.AvailableBytesIn = count;
-        bool done = false;
+        var done = false;
         do
         {
             _z.OutputBuffer = workingBuffer;
             _z.NextOut = 0;
             _z.AvailableBytesOut = _workingBuffer.Length;
-            int rc = (_wantCompress) ? _z.Deflate(_flushMode) : _z.Inflate(_flushMode);
+            var rc = (_wantCompress) ? _z.Deflate(_flushMode) : _z.Inflate(_flushMode);
             if (rc != ZlibConstants.Z_OK && rc != ZlibConstants.Z_STREAM_END)
             {
                 throw new ZlibException((_wantCompress ? "de" : "in") + "flating: " + _z.Message);
@@ -181,18 +181,18 @@ internal class ZlibBaseStream : Stream
 
         if (_streamMode == StreamMode.Writer)
         {
-            bool done = false;
+            var done = false;
             do
             {
                 _z.OutputBuffer = workingBuffer;
                 _z.NextOut = 0;
                 _z.AvailableBytesOut = _workingBuffer.Length;
-                int rc =
+                var rc =
                     (_wantCompress) ? _z.Deflate(FlushType.Finish) : _z.Inflate(FlushType.Finish);
 
                 if (rc != ZlibConstants.Z_STREAM_END && rc != ZlibConstants.Z_OK)
                 {
-                    string verb = (_wantCompress ? "de" : "in") + "flating";
+                    var verb = (_wantCompress ? "de" : "in") + "flating";
                     if (_z.Message is null)
                     {
                         throw new ZlibException(String.Format("{0}: (rc = {1})", verb, rc));
@@ -225,7 +225,7 @@ internal class ZlibBaseStream : Stream
                     Span<byte> intBuf = stackalloc byte[4];
                     BinaryPrimitives.WriteInt32LittleEndian(intBuf, crc.Crc32Result);
                     _stream.Write(intBuf);
-                    int c2 = (int)(crc.TotalBytesRead & 0x00000000FFFFFFFF);
+                    var c2 = (int)(crc.TotalBytesRead & 0x00000000FFFFFFFF);
                     BinaryPrimitives.WriteInt32LittleEndian(intBuf, c2);
                     _stream.Write(intBuf);
                 }
@@ -256,8 +256,8 @@ internal class ZlibBaseStream : Stream
                     {
                         // Make sure we have read to the end of the stream
                         _z.InputBuffer.AsSpan(_z.NextIn, _z.AvailableBytesIn).CopyTo(trailer);
-                        int bytesNeeded = 8 - _z.AvailableBytesIn;
-                        int bytesRead = _stream.Read(
+                        var bytesNeeded = 8 - _z.AvailableBytesIn;
+                        var bytesRead = _stream.Read(
                             trailer.Slice(_z.AvailableBytesIn, bytesNeeded)
                         );
                         if (bytesNeeded != bytesRead)
@@ -275,10 +275,10 @@ internal class ZlibBaseStream : Stream
                         _z.InputBuffer.AsSpan(_z.NextIn, trailer.Length).CopyTo(trailer);
                     }
 
-                    Int32 crc32_expected = BinaryPrimitives.ReadInt32LittleEndian(trailer);
-                    Int32 crc32_actual = crc.Crc32Result;
-                    Int32 isize_expected = BinaryPrimitives.ReadInt32LittleEndian(trailer.Slice(4));
-                    Int32 isize_actual = (Int32)(_z.TotalBytesOut & 0x00000000FFFFFFFF);
+                    var crc32_expected = BinaryPrimitives.ReadInt32LittleEndian(trailer);
+                    var crc32_actual = crc.Crc32Result;
+                    var isize_expected = BinaryPrimitives.ReadInt32LittleEndian(trailer.Slice(4));
+                    var isize_actual = (Int32)(_z.TotalBytesOut & 0x00000000FFFFFFFF);
 
                     if (crc32_actual != crc32_expected)
                     {
@@ -380,11 +380,11 @@ internal class ZlibBaseStream : Stream
     private string ReadZeroTerminatedString()
     {
         var list = new List<byte>();
-        bool done = false;
+        var done = false;
         do
         {
             // workitem 7740
-            int n = _stream.Read(_buf1, 0, 1);
+            var n = _stream.Read(_buf1, 0, 1);
             if (n != 1)
             {
                 throw new ZlibException("Unexpected EOF reading GZIP header.");
@@ -398,17 +398,17 @@ internal class ZlibBaseStream : Stream
                 list.Add(_buf1[0]);
             }
         } while (!done);
-        byte[] buffer = list.ToArray();
+        var buffer = list.ToArray();
         return _encoding.GetString(buffer, 0, buffer.Length);
     }
 
     private int _ReadAndValidateGzipHeader()
     {
-        int totalBytesRead = 0;
+        var totalBytesRead = 0;
 
         // read the header on the first read
         Span<byte> header = stackalloc byte[10];
-        int n = _stream.Read(header);
+        var n = _stream.Read(header);
 
         // workitem 8501: handle edge case (decompress empty stream)
         if (n == 0)
@@ -426,7 +426,7 @@ internal class ZlibBaseStream : Stream
             throw new ZlibException("Bad GZIP header.");
         }
 
-        int timet = BinaryPrimitives.ReadInt32LittleEndian(header.Slice(4));
+        var timet = BinaryPrimitives.ReadInt32LittleEndian(header.Slice(4));
         _GzipMtime = TarHeader.EPOCH.AddSeconds(timet);
         totalBytesRead += n;
         if ((header[3] & 0x04) == 0x04)
@@ -435,8 +435,8 @@ internal class ZlibBaseStream : Stream
             n = _stream.Read(header.Slice(0, 2)); // 2-byte length field
             totalBytesRead += n;
 
-            short extraLength = (short)(header[0] + header[1] * 256);
-            byte[] extra = new byte[extraLength];
+            var extraLength = (short)(header[0] + header[1] * 256);
+            var extra = new byte[extraLength];
             n = _stream.Read(extra, 0, extra.Length);
             if (n != extraLength)
             {
@@ -498,7 +498,7 @@ internal class ZlibBaseStream : Stream
             throw new ZlibException("Cannot Read after Writing.");
         }
 
-        int rc = 0;
+        var rc = 0;
 
         // set up the output of the deflate/inflate codec:
         _z.OutputBuffer = buffer;

src/SharpCompress/Compressors/Deflate64/Deflate64Stream.cs

@@ -4,11 +4,11 @@
 
 #nullable disable
 
-using SharpCompress.Common.Zip;
 using System;
 using System.Diagnostics;
 using System.IO;
 using System.Runtime.CompilerServices;
+using SharpCompress.Common.Zip;
 
 namespace SharpCompress.Compressors.Deflate64;
 
@@ -118,8 +118,8 @@ public sealed class Deflate64Stream : Stream
         EnsureNotDisposed();
 
         int bytesRead;
-        int currentOffset = offset;
-        int remainingCount = count;
+        var currentOffset = offset;
+        var remainingCount = count;
 
         while (true)
         {
@@ -142,7 +142,7 @@ public sealed class Deflate64Stream : Stream
                 break;
             }
 
-            int bytes = _stream.Read(_buffer, 0, _buffer.Length);
+            var bytes = _stream.Read(_buffer, 0, _buffer.Length);
             if (bytes <= 0)
             {
                 break;

src/SharpCompress/Compressors/Deflate64/DeflateInput.cs

@@ -22,7 +22,7 @@ internal sealed class DeflateInput
         Debug.Assert(StartIndex + Count <= Buffer.Length, "Input buffer is in invalid state!");
     }
 
-    internal InputState DumpState() => new InputState(Count, StartIndex);
+    internal InputState DumpState() => new(Count, StartIndex);
 
     internal void RestoreState(InputState state)
     {

src/SharpCompress/Compressors/Deflate64/HuffmanTree.cs

@@ -42,11 +42,9 @@ internal sealed class HuffmanTree
     private readonly int _tableMask;
 
     // huffman tree for static block
-    public static HuffmanTree StaticLiteralLengthTree { get; } =
-        new HuffmanTree(GetStaticLiteralTreeLength());
+    public static HuffmanTree StaticLiteralLengthTree { get; } = new(GetStaticLiteralTreeLength());
 
-    public static HuffmanTree StaticDistanceTree { get; } =
-        new HuffmanTree(GetStaticDistanceTreeLength());
+    public static HuffmanTree StaticDistanceTree { get; } = new(GetStaticDistanceTreeLength());
 
     public HuffmanTree(byte[] codeLengths)
     {

src/SharpCompress/Compressors/Deflate64/InflaterManaged.cs

@@ -243,8 +243,8 @@ internal sealed class InflaterManaged
 
     private void Reset() =>
         _state = //_hasFormatReader ?
-        //InflaterState.ReadingHeader :   // start by reading Header info
-        InflaterState.ReadingBFinal; // start by reading BFinal bit
+            //InflaterState.ReadingHeader :   // start by reading Header info
+            InflaterState.ReadingBFinal; // start by reading BFinal bit
 
     public void SetInput(byte[] inputBytes, int offset, int length) =>
         _input.SetInput(inputBytes, offset, length); // append the bytes

src/SharpCompress/Compressors/Filters/BCJ2Filter.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 
 namespace SharpCompress.Compressors.Filters;
@@ -79,7 +79,7 @@ internal class BCJ2Filter : Stream
 
     public override bool CanWrite => false;
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override long Length => _baseStream.Length + _data1.Length + _data2.Length;
 

src/SharpCompress/Compressors/Filters/BCJFilterARM.cs

@@ -18,7 +18,7 @@ internal class BCJFilterARM : Filter
         {
             if ((buffer[i + 3] & 0xFF) == 0xEB)
             {
-                int src =
+                var src =
                     ((buffer[i + 2] & 0xFF) << 16)
                     | ((buffer[i + 1] & 0xFF) << 8)
                     | (buffer[i] & 0xFF);

src/SharpCompress/Compressors/Filters/BCJFilterARMT.cs

@@ -18,7 +18,7 @@ internal class BCJFilterARMT : Filter
         {
             if ((buffer[i + 1] & 0xF8) == 0xF0 && (buffer[i + 3] & 0xF8) == 0xF8)
             {
-                int src =
+                var src =
                     ((buffer[i + 1] & 0x07) << 19)
                     | ((buffer[i] & 0xFF) << 11)
                     | ((buffer[i + 3] & 0x07) << 8)

src/SharpCompress/Compressors/Filters/BCJFilterIA64.cs

@@ -52,29 +52,29 @@ internal class BCJFilterIA64 : Filter
 
         for (i = offset; i <= end; i += 16)
         {
-            int instrTemplate = buffer[i] & 0x1F;
-            int mask = BRANCH_TABLE[instrTemplate];
+            var instrTemplate = buffer[i] & 0x1F;
+            var mask = BRANCH_TABLE[instrTemplate];
 
             for (int slot = 0, bitPos = 5; slot < 3; ++slot, bitPos += 41)
             {
                 if (((mask >>> slot) & 1) == 0)
                     continue;
 
-                int bytePos = bitPos >>> 3;
-                int bitRes = bitPos & 7;
+                var bytePos = bitPos >>> 3;
+                var bitRes = bitPos & 7;
 
                 long instr = 0;
-                for (int j = 0; j < 6; ++j)
+                for (var j = 0; j < 6; ++j)
                 {
                     instr |= (buffer[i + bytePos + j] & 0xFFL) << (8 * j);
                 }
 
-                long instrNorm = instr >>> bitRes;
+                var instrNorm = instr >>> bitRes;
 
                 if (((instrNorm >>> 37) & 0x0F) != 0x05 || ((instrNorm >>> 9) & 0x07) != 0x00)
                     continue;
 
-                int src = (int)((instrNorm >>> 13) & 0x0FFFFF);
+                var src = (int)((instrNorm >>> 13) & 0x0FFFFF);
                 src |= ((int)(instrNorm >>> 36) & 1) << 20;
                 src <<= 4;
 
@@ -93,7 +93,7 @@ internal class BCJFilterIA64 : Filter
                 instr &= (1 << bitRes) - 1;
                 instr |= instrNorm << bitRes;
 
-                for (int j = 0; j < 6; ++j)
+                for (var j = 0; j < 6; ++j)
                 {
                     buffer[i + bytePos + j] = (byte)(instr >>> (8 * j));
                 }

src/SharpCompress/Compressors/Filters/BCJFilterPPC.cs

@@ -18,7 +18,7 @@ internal class BCJFilterPPC : Filter
         {
             if ((buffer[i] & 0xFC) == 0x48 && (buffer[i + 3] & 0x03) == 0x01)
             {
-                int src =
+                var src =
                     ((buffer[i] & 0x03) << 24)
                     | ((buffer[i + 1] & 0xFF) << 16)
                     | ((buffer[i + 2] & 0xFF) << 8)

src/SharpCompress/Compressors/Filters/BCJFilterSPARC.cs

@@ -21,7 +21,7 @@ internal class BCJFilterSPARC : Filter
                 || (buffer[i] == 0x7F && (buffer[i + 1] & 0xC0) == 0xC0)
             )
             {
-                int src =
+                var src =
                     ((buffer[i] & 0xFF) << 24)
                     | ((buffer[i + 1] & 0xFF) << 16)
                     | ((buffer[i + 2] & 0xFF) << 8)

src/SharpCompress/Compressors/Filters/BranchExecFilter.cs

@@ -24,40 +24,27 @@ public sealed class BranchExecFilter
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static bool X86TestByte(byte b)
-    {
-        return b == 0x00 || b == 0xFF;
-    }
+    private static bool X86TestByte(byte b) => b == 0x00 || b == 0xFF;
 
     //Replaced X86Converter with bcj_x86() - https://github.com/torvalds/linux/blob/master/lib/xz/xz_dec_bcj.c
     //This was to fix an issue decoding a Test zip made with WinZip (that 7zip was also able to read).
     //The previous version of the code would corrupt 2 bytes in the Test.exe at 0x6CF9 (3D6D - should be 4000) - Test zip: WinZip27.Xz.zipx
     public static void X86Converter(byte[] buf, uint ip, ref uint state)
     {
-        bool[] mask_to_allowed_status = new[]
-        {
-            true,
-            true,
-            true,
-            false,
-            true,
-            false,
-            false,
-            false
-        };
+        var mask_to_allowed_status = new[] { true, true, true, false, true, false, false, false };
 
-        byte[] mask_to_bit_num = new byte[] { 0, 1, 2, 2, 3, 3, 3, 3 };
+        var mask_to_bit_num = new byte[] { 0, 1, 2, 2, 3, 3, 3, 3 };
 
         int i;
-        int prev_pos = -1;
-        uint prev_mask = state & 7;
+        var prev_pos = -1;
+        var prev_mask = state & 7;
         uint src;
         uint dest;
         uint j;
         byte b;
-        uint pos = ip;
+        var pos = ip;
 
-        uint size = (uint)buf.Length;
+        var size = (uint)buf.Length;
 
         if (size <= 4)
             return;

src/SharpCompress/Compressors/Filters/DeltaFilter.cs

@@ -23,9 +23,9 @@ namespace SharpCompress.Compressors.Filters
 
         protected override int Transform(byte[] buffer, int offset, int count)
         {
-            int end = offset + count;
+            var end = offset + count;
 
-            for (int i = offset; i < end; i++)
+            for (var i = offset; i < end; i++)
             {
                 buffer[i] += _history[(_distance + _position--) & DISTANCE_MASK];
                 _history[_position & DISTANCE_MASK] = buffer[i];

src/SharpCompress/Compressors/Filters/Filter.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 
 namespace SharpCompress.Compressors.Filters;
@@ -40,7 +40,7 @@ internal abstract class Filter : Stream
 
     public override bool CanWrite => _isEncoder;
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override long Length => _baseStream.Length;
 

src/SharpCompress/Compressors/LZMA/AesDecoderStream.cs

@@ -35,10 +35,10 @@ internal sealed class AesDecoderStream : DecoderStream2
             throw new NotSupportedException("AES decoder does not support padding.");
         }
 
-        Init(info, out int numCyclesPower, out byte[] salt, out byte[] seed);
+        Init(info, out var numCyclesPower, out var salt, out var seed);
 
-        byte[] password = Encoding.Unicode.GetBytes(pass.CryptoGetTextPassword());
-        byte[]? key = InitKey(numCyclesPower, salt, password);
+        var password = Encoding.Unicode.GetBytes(pass.CryptoGetTextPassword());
+        var key = InitKey(numCyclesPower, salt, password);
         if (key == null)
         {
             throw new InvalidOperationException("Initialized with null key");
@@ -100,7 +100,7 @@ internal sealed class AesDecoderStream : DecoderStream2
 
             do
             {
-                int read = mStream.Read(mBuffer, mEnding, mBuffer.Length - mEnding);
+                var read = mStream.Read(mBuffer, mEnding, mBuffer.Length - mEnding);
                 if (read == 0)
                 {
                     // We are not done decoding and have less than 16 bytes.
@@ -133,7 +133,7 @@ internal sealed class AesDecoderStream : DecoderStream2
         }
 
         // Otherwise we transform directly into the target buffer.
-        int processed = mDecoder.TransformBlock(mBuffer, mOffset, count & ~15, buffer, offset);
+        var processed = mDecoder.TransformBlock(mBuffer, mOffset, count & ~15, buffer, offset);
         mOffset += processed;
         mWritten += processed;
         return processed;
@@ -143,7 +143,7 @@ internal sealed class AesDecoderStream : DecoderStream2
 
     private void Init(byte[] info, out int numCyclesPower, out byte[] salt, out byte[] iv)
     {
-        byte bt = info[0];
+        var bt = info[0];
         numCyclesPower = bt & 0x3F;
 
         if ((bt & 0xC0) == 0)
@@ -153,14 +153,14 @@ internal sealed class AesDecoderStream : DecoderStream2
             return;
         }
 
-        int saltSize = (bt >> 7) & 1;
-        int ivSize = (bt >> 6) & 1;
+        var saltSize = (bt >> 7) & 1;
+        var ivSize = (bt >> 6) & 1;
         if (info.Length == 1)
         {
             throw new InvalidOperationException();
         }
 
-        byte bt2 = info[1];
+        var bt2 = info[1];
         saltSize += (bt2 >> 4);
         ivSize += (bt2 & 15);
         if (info.Length < 2 + saltSize + ivSize)
@@ -169,13 +169,13 @@ internal sealed class AesDecoderStream : DecoderStream2
         }
 
         salt = new byte[saltSize];
-        for (int i = 0; i < saltSize; i++)
+        for (var i = 0; i < saltSize; i++)
         {
             salt[i] = info[i + 2];
         }
 
         iv = new byte[16];
-        for (int i = 0; i < ivSize; i++)
+        for (var i = 0; i < ivSize; i++)
         {
             iv[i] = info[i + saltSize + 2];
         }
@@ -198,7 +198,7 @@ internal sealed class AesDecoderStream : DecoderStream2
                 key[pos] = salt[pos];
             }
 
-            for (int i = 0; i < pass.Length && pos < 32; i++)
+            for (var i = 0; i < pass.Length && pos < 32; i++)
             {
                 key[pos++] = pass[i];
             }
@@ -208,9 +208,9 @@ internal sealed class AesDecoderStream : DecoderStream2
         else
         {
 #if NETSTANDARD2_0
-            using IncrementalHash sha = IncrementalHash.CreateHash(HashAlgorithmName.SHA256);
-            byte[] counter = new byte[8];
-            long numRounds = 1L << mNumCyclesPower;
+            using var sha = IncrementalHash.CreateHash(HashAlgorithmName.SHA256);
+            var counter = new byte[8];
+            var numRounds = 1L << mNumCyclesPower;
             for (long round = 0; round < numRounds; round++)
             {
                 sha.AppendData(salt, 0, salt.Length);
@@ -219,7 +219,7 @@ internal sealed class AesDecoderStream : DecoderStream2
 
                 // This mirrors the counter so we don't have to convert long to byte[] each round.
                 // (It also ensures the counter is little endian, which BitConverter does not.)
-                for (int i = 0; i < 8; i++)
+                for (var i = 0; i < 8; i++)
                 {
                     if (++counter[i] != 0)
                     {
@@ -230,8 +230,8 @@ internal sealed class AesDecoderStream : DecoderStream2
             return sha.GetHashAndReset();
 #else
             using var sha = SHA256.Create();
-            byte[] counter = new byte[8];
-            long numRounds = 1L << mNumCyclesPower;
+            var counter = new byte[8];
+            var numRounds = 1L << mNumCyclesPower;
             for (long round = 0; round < numRounds; round++)
             {
                 sha.TransformBlock(salt, 0, salt.Length, null, 0);
@@ -240,7 +240,7 @@ internal sealed class AesDecoderStream : DecoderStream2
 
                 // This mirrors the counter so we don't have to convert long to byte[] each round.
                 // (It also ensures the counter is little endian, which BitConverter does not.)
-                for (int i = 0; i < 8; i++)
+                for (var i = 0; i < 8; i++)
                 {
                     if (++counter[i] != 0)
                     {
@@ -261,7 +261,7 @@ internal sealed class AesDecoderStream : DecoderStream2
         // Just transform as much as possible so we can feed from it as long as possible.
         if (mUnderflow == 0)
         {
-            int blockSize = (mEnding - mOffset) & ~15;
+            var blockSize = (mEnding - mOffset) & ~15;
             mUnderflow = mDecoder.TransformBlock(mBuffer, mOffset, blockSize, mBuffer, mOffset);
         }
 

src/SharpCompress/Compressors/LZMA/DecoderStream.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.IO;
 using SharpCompress.Common.SevenZip;
 using SharpCompress.Compressors.LZMA.Utilites;
@@ -14,7 +14,7 @@ internal abstract class DecoderStream2 : Stream
 
     public override bool CanWrite => false;
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override long Length => throw new NotSupportedException();
 

src/SharpCompress/Compressors/LZMA/Log.cs

@@ -6,7 +6,7 @@ namespace SharpCompress.Compressors.LZMA;
 
 internal static class Log
 {
-    private static readonly Stack<string> INDENT = new Stack<string>();
+    private static readonly Stack<string> INDENT = new();
     private static bool NEEDS_INDENT = true;
 
     static Log() => INDENT.Push("");

src/SharpCompress/Compressors/LZMA/LzmaDecoder.cs

@@ -11,11 +11,11 @@ public class Decoder : ICoder, ISetDecoderProperties // ,System.IO.Stream
 {
     private class LenDecoder
     {
-        private BitDecoder _choice = new BitDecoder();
-        private BitDecoder _choice2 = new BitDecoder();
+        private BitDecoder _choice = new();
+        private BitDecoder _choice2 = new();
         private readonly BitTreeDecoder[] _lowCoder = new BitTreeDecoder[Base.K_NUM_POS_STATES_MAX];
         private readonly BitTreeDecoder[] _midCoder = new BitTreeDecoder[Base.K_NUM_POS_STATES_MAX];
-        private BitTreeDecoder _highCoder = new BitTreeDecoder(Base.K_NUM_HIGH_LEN_BITS);
+        private BitTreeDecoder _highCoder = new(Base.K_NUM_HIGH_LEN_BITS);
         private uint _numPosStates;
 
         public void Create(uint numPosStates)
@@ -173,18 +173,18 @@ public class Decoder : ICoder, ISetDecoderProperties // ,System.IO.Stream
         Base.K_NUM_FULL_DISTANCES - Base.K_END_POS_MODEL_INDEX
     ];
 
-    private BitTreeDecoder _posAlignDecoder = new BitTreeDecoder(Base.K_NUM_ALIGN_BITS);
+    private BitTreeDecoder _posAlignDecoder = new(Base.K_NUM_ALIGN_BITS);
 
-    private readonly LenDecoder _lenDecoder = new LenDecoder();
-    private readonly LenDecoder _repLenDecoder = new LenDecoder();
+    private readonly LenDecoder _lenDecoder = new();
+    private readonly LenDecoder _repLenDecoder = new();
 
-    private readonly LiteralDecoder _literalDecoder = new LiteralDecoder();
+    private readonly LiteralDecoder _literalDecoder = new();
 
     private int _dictionarySize;
 
     private uint _posStateMask;
 
-    private Base.State _state = new Base.State();
+    private Base.State _state = new();
     private uint _rep0,
         _rep1,
         _rep2,
@@ -318,9 +318,8 @@ public class Decoder : ICoder, ISetDecoderProperties // ,System.IO.Stream
         {
             var posState = (uint)outWindow._total & _posStateMask;
             if (
-                _isMatchDecoders[
-                    (_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState
-                ].Decode(rangeDecoder) == 0
+                _isMatchDecoders[(_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState]
+                    .Decode(rangeDecoder) == 0
             )
             {
                 byte b;
@@ -355,7 +354,8 @@ public class Decoder : ICoder, ISetDecoderProperties // ,System.IO.Stream
                         if (
                             _isRep0LongDecoders[
                                 (_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState
-                            ].Decode(rangeDecoder) == 0
+                            ]
+                                .Decode(rangeDecoder) == 0
                         )
                         {
                             _state.UpdateShortRep();

src/SharpCompress/Compressors/LZMA/LzmaEncoder.cs

@@ -61,7 +61,7 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
         return (uint)(G_FAST_POS[pos >> 26] + 52);
     }
 
-    private Base.State _state = new Base.State();
+    private Base.State _state = new();
     private byte _previousByte;
     private readonly uint[] _repDistances = new uint[Base.K_NUM_REP_DISTANCES];
 
@@ -191,15 +191,15 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
 
     private class LenEncoder
     {
-        private BitEncoder _choice = new BitEncoder();
-        private BitEncoder _choice2 = new BitEncoder();
+        private BitEncoder _choice = new();
+        private BitEncoder _choice2 = new();
         private readonly BitTreeEncoder[] _lowCoder = new BitTreeEncoder[
             Base.K_NUM_POS_STATES_ENCODING_MAX
         ];
         private readonly BitTreeEncoder[] _midCoder = new BitTreeEncoder[
             Base.K_NUM_POS_STATES_ENCODING_MAX
         ];
-        private BitTreeEncoder _highCoder = new BitTreeEncoder(Base.K_NUM_HIGH_LEN_BITS);
+        private BitTreeEncoder _highCoder = new(Base.K_NUM_HIGH_LEN_BITS);
 
         public LenEncoder()
         {
@@ -359,7 +359,7 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
 
     private readonly Optimal[] _optimum = new Optimal[K_NUM_OPTS];
     private BinTree _matchFinder;
-    private readonly RangeCoder.Encoder _rangeEncoder = new RangeCoder.Encoder();
+    private readonly RangeCoder.Encoder _rangeEncoder = new();
 
     private readonly BitEncoder[] _isMatch = new BitEncoder[
         Base.K_NUM_STATES << Base.K_NUM_POS_STATES_BITS_MAX
@@ -382,12 +382,12 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
         Base.K_NUM_FULL_DISTANCES - Base.K_END_POS_MODEL_INDEX
     ];
 
-    private BitTreeEncoder _posAlignEncoder = new BitTreeEncoder(Base.K_NUM_ALIGN_BITS);
+    private BitTreeEncoder _posAlignEncoder = new(Base.K_NUM_ALIGN_BITS);
 
-    private readonly LenPriceTableEncoder _lenEncoder = new LenPriceTableEncoder();
-    private readonly LenPriceTableEncoder _repMatchLenEncoder = new LenPriceTableEncoder();
+    private readonly LenPriceTableEncoder _lenEncoder = new();
+    private readonly LenPriceTableEncoder _repMatchLenEncoder = new();
 
-    private readonly LiteralEncoder _literalEncoder = new LiteralEncoder();
+    private readonly LiteralEncoder _literalEncoder = new();
 
     private readonly uint[] _matchDistances = new uint[(Base.K_MATCH_MAX_LEN * 2) + 2];
 
@@ -553,9 +553,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
         if (repIndex == 0)
         {
             price = _isRepG0[state._index].GetPrice0();
-            price += _isRep0Long[
-                (state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState
-            ].GetPrice1();
+            price += _isRep0Long[(state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState]
+                .GetPrice1();
         }
         else
         {
@@ -713,9 +712,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
                 .GetPrice(!_state.IsCharState(), matchByte, currentByte);
         _optimum[1].MakeAsChar();
 
-        var matchPrice = _isMatch[
-            (_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState
-        ].GetPrice1();
+        var matchPrice = _isMatch[(_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState]
+            .GetPrice1();
         var repMatchPrice = matchPrice + _isRep[_state._index].GetPrice1();
 
         if (matchByte == currentByte)
@@ -995,9 +993,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
                     var posStateNext = (position + 1) & _posStateMask;
                     var nextRepMatchPrice =
                         curAnd1Price
-                        + _isMatch[
-                            (state2._index << Base.K_NUM_POS_STATES_BITS_MAX) + posStateNext
-                        ].GetPrice1()
+                        + _isMatch[(state2._index << Base.K_NUM_POS_STATES_BITS_MAX) + posStateNext]
+                            .GetPrice1()
                         + _isRep[state2._index].GetPrice1();
                     {
                         var offset = cur + 1 + lenTest2;
@@ -1069,7 +1066,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
                             + GetRepPrice(repIndex, lenTest, state, posState)
                             + _isMatch[
                                 (state2._index << Base.K_NUM_POS_STATES_BITS_MAX) + posStateNext
-                            ].GetPrice0()
+                            ]
+                                .GetPrice0()
                             + _literalEncoder
                                 .GetSubCoder(
                                     position + lenTest,
@@ -1088,7 +1086,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
                             curAndLenCharPrice
                             + _isMatch[
                                 (state2._index << Base.K_NUM_POS_STATES_BITS_MAX) + posStateNext
-                            ].GetPrice1();
+                            ]
+                                .GetPrice1();
                         var nextRepMatchPrice = nextMatchPrice + _isRep[state2._index].GetPrice1();
 
                         // for(; lenTest2 >= 2; lenTest2--)
@@ -1174,7 +1173,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
                                     + _isMatch[
                                         (state2._index << Base.K_NUM_POS_STATES_BITS_MAX)
                                             + posStateNext
-                                    ].GetPrice0()
+                                    ]
+                                        .GetPrice0()
                                     + _literalEncoder
                                         .GetSubCoder(
                                             position + lenTest,
@@ -1194,7 +1194,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
                                     + _isMatch[
                                         (state2._index << Base.K_NUM_POS_STATES_BITS_MAX)
                                             + posStateNext
-                                    ].GetPrice1();
+                                    ]
+                                        .GetPrice1();
                                 var nextRepMatchPrice =
                                     nextMatchPrice + _isRep[state2._index].GetPrice1();
 
@@ -1243,10 +1244,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
             return;
         }
 
-        _isMatch[(_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState].Encode(
-            _rangeEncoder,
-            1
-        );
+        _isMatch[(_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState]
+            .Encode(_rangeEncoder, 1);
         _isRep[_state._index].Encode(_rangeEncoder, 0);
         _state.UpdateMatch();
         var len = Base.K_MATCH_MIN_LEN;
@@ -1321,10 +1320,8 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
             // it's not used
             ReadMatchDistances(out var len, out var numDistancePairs);
             var posState = (uint)(_nowPos64) & _posStateMask;
-            _isMatch[(_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState].Encode(
-                _rangeEncoder,
-                0
-            );
+            _isMatch[(_state._index << Base.K_NUM_POS_STATES_BITS_MAX) + posState]
+                .Encode(_rangeEncoder, 0);
             _state.UpdateChar();
             var curByte = _matchFinder.GetIndexByte((int)(0 - _additionalOffset));
             _literalEncoder
@@ -1730,7 +1727,7 @@ internal class Encoder : ICoder, ISetCoderProperties, IWriteCoderProperties
         ReadOnlySpan<object> properties
     )
     {
-        for (int i = 0; i < properties.Length; i++)
+        for (var i = 0; i < properties.Length; i++)
         {
             var prop = properties[i];
             switch (propIDs[i])

src/SharpCompress/Compressors/LZMA/LzmaStream.cs

@@ -14,8 +14,8 @@ public class LzmaStream : Stream
     private readonly long _outputSize;
 
     private readonly int _dictionarySize;
-    private readonly OutWindow _outWindow = new OutWindow();
-    private readonly RangeCoder.Decoder _rangeDecoder = new RangeCoder.Decoder();
+    private readonly OutWindow _outWindow = new();
+    private readonly RangeCoder.Decoder _rangeDecoder = new();
     private Decoder _decoder;
 
     private long _position;
@@ -207,14 +207,23 @@ public class LzmaStream : Stream
 
             if (_availableBytes == 0 && !_uncompressedChunk)
             {
-                _rangeDecoder.ReleaseStream();
+                // Check range corruption scenario
                 if (
                     !_rangeDecoder.IsFinished
                     || (_rangeDecoderLimit >= 0 && _rangeDecoder._total != _rangeDecoderLimit)
                 )
                 {
-                    throw new DataErrorException();
+                    // Stream might have End Of Stream marker
+                    _outWindow.SetLimit(toProcess + 1);
+                    if (!_decoder.Code(_dictionarySize, _outWindow, _rangeDecoder))
+                    {
+                        _rangeDecoder.ReleaseStream();
+                        throw new DataErrorException();
+                    }
                 }
+
+                _rangeDecoder.ReleaseStream();
+
                 _inputPosition += _rangeDecoder._total;
                 if (_outWindow.HasPending)
                 {

src/SharpCompress/Compressors/Lzw/LzwConstants.cs

@@ -0,0 +1,65 @@
+namespace SharpCompress.Compressors.Lzw
+{
+    /// <summary>
+    /// This class contains constants used for LZW
+    /// </summary>
+    [System.Diagnostics.CodeAnalysis.SuppressMessage(
+        "Naming",
+        "CA1707:Identifiers should not contain underscores",
+        Justification = "kept for backwards compatibility"
+    )]
+    public sealed class LzwConstants
+    {
+        /// <summary>
+        /// Magic number found at start of LZW header: 0x1f 0x9d
+        /// </summary>
+        public const int MAGIC = 0x1f9d;
+
+        /// <summary>
+        /// Maximum number of bits per code
+        /// </summary>
+        public const int MAX_BITS = 16;
+
+        /* 3rd header byte:
+         * bit 0..4 Number of compression bits
+         * bit 5    Extended header
+         * bit 6    Free
+         * bit 7    Block mode
+         */
+
+        /// <summary>
+        /// Mask for 'number of compression bits'
+        /// </summary>
+        public const int BIT_MASK = 0x1f;
+
+        /// <summary>
+        /// Indicates the presence of a fourth header byte
+        /// </summary>
+        public const int EXTENDED_MASK = 0x20;
+
+        //public const int FREE_MASK      = 0x40;
+
+        /// <summary>
+        /// Reserved bits
+        /// </summary>
+        public const int RESERVED_MASK = 0x60;
+
+        /// <summary>
+        /// Block compression: if table is full and compression rate is dropping,
+        /// clear the dictionary.
+        /// </summary>
+        public const int BLOCK_MODE_MASK = 0x80;
+
+        /// <summary>
+        /// LZW file header size (in bytes)
+        /// </summary>
+        public const int HDR_SIZE = 3;
+
+        /// <summary>
+        /// Initial number of bits per code
+        /// </summary>
+        public const int INIT_BITS = 9;
+
+        private LzwConstants() { }
+    }
+}

src/SharpCompress/Compressors/Lzw/LzwStream.cs

@@ -0,0 +1,597 @@
+using System;
+using System.IO;
+using SharpCompress.Common;
+
+namespace SharpCompress.Compressors.Lzw
+{
+    /// <summary>
+    /// This filter stream is used to decompress a LZW format stream.
+    /// Specifically, a stream that uses the LZC compression method.
+    /// This file format is usually associated with the .Z file extension.
+    ///
+    /// See http://en.wikipedia.org/wiki/Compress
+    /// See http://wiki.wxwidgets.org/Development:_Z_File_Format
+    ///
+    /// The file header consists of 3 (or optionally 4) bytes. The first two bytes
+    /// contain the magic marker "0x1f 0x9d", followed by a byte of flags.
+    ///
+    /// Based on Java code by Ronald Tschalar, which in turn was based on the unlzw.c
+    /// code in the gzip package.
+    /// </summary>
+    /// <example> This sample shows how to unzip a compressed file
+    /// <code>
+    /// using System;
+    /// using System.IO;
+    ///
+    /// using ICSharpCode.SharpZipLib.Core;
+    /// using ICSharpCode.SharpZipLib.LZW;
+    ///
+    /// class MainClass
+    /// {
+    /// 	public static void Main(string[] args)
+    /// 	{
+    ///			using (Stream inStream = new LzwInputStream(File.OpenRead(args[0])))
+    ///			using (FileStream outStream = File.Create(Path.GetFileNameWithoutExtension(args[0]))) {
+    ///				byte[] buffer = new byte[4096];
+    ///				StreamUtils.Copy(inStream, outStream, buffer);
+    ///                         // OR
+    ///                         inStream.Read(buffer, 0, buffer.Length);
+    ///                         // now do something with the buffer
+    /// 		}
+    /// 	}
+    /// }
+    /// </code>
+    /// </example>
+    public class LzwStream : Stream
+    {
+        public static bool IsLzwStream(Stream stream)
+        {
+            try
+            {
+                byte[] hdr = new byte[LzwConstants.HDR_SIZE];
+
+                int result = stream.Read(hdr, 0, hdr.Length);
+
+                // Check the magic marker
+                if (result < 0)
+                    throw new IncompleteArchiveException("Failed to read LZW header");
+
+                if (hdr[0] != (LzwConstants.MAGIC >> 8) || hdr[1] != (LzwConstants.MAGIC & 0xff))
+                {
+                    throw new IncompleteArchiveException(
+                        String.Format(
+                            "Wrong LZW header. Magic bytes don't match. 0x{0:x2} 0x{1:x2}",
+                            hdr[0],
+                            hdr[1]
+                        )
+                    );
+                }
+            }
+            catch (Exception)
+            {
+                return false;
+            }
+            return true;
+        }
+
+        /// <summary>
+        /// Gets or sets a flag indicating ownership of underlying stream.
+        /// When the flag is true <see cref="Stream.Dispose()" /> will close the underlying stream also.
+        /// </summary>
+        /// <remarks>The default value is true.</remarks>
+        public bool IsStreamOwner { get; set; } = false;
+
+        /// <summary>
+        /// Creates a LzwInputStream
+        /// </summary>
+        /// <param name="baseInputStream">
+        /// The stream to read compressed data from (baseInputStream LZW format)
+        /// </param>
+        public LzwStream(Stream baseInputStream)
+        {
+            this.baseInputStream = baseInputStream;
+        }
+
+        /// <summary>
+        /// See <see cref="System.IO.Stream.ReadByte"/>
+        /// </summary>
+        /// <returns></returns>
+        public override int ReadByte()
+        {
+            int b = Read(one, 0, 1);
+            if (b == 1)
+                return (one[0] & 0xff);
+            return -1;
+        }
+
+        /// <summary>
+        /// Reads decompressed data into the provided buffer byte array
+        /// </summary>
+        /// <param name ="buffer">
+        /// The array to read and decompress data into
+        /// </param>
+        /// <param name ="offset">
+        /// The offset indicating where the data should be placed
+        /// </param>
+        /// <param name ="count">
+        /// The number of bytes to decompress
+        /// </param>
+        /// <returns>The number of bytes read. Zero signals the end of stream</returns>
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            if (!headerParsed)
+                ParseHeader();
+
+            if (eof)
+                return 0;
+
+            int start = offset;
+
+            /* Using local copies of various variables speeds things up by as
+             * much as 30% in Java! Performance not tested in C#.
+             */
+            int[] lTabPrefix = tabPrefix;
+            byte[] lTabSuffix = tabSuffix;
+            byte[] lStack = stack;
+            int lNBits = nBits;
+            int lMaxCode = maxCode;
+            int lMaxMaxCode = maxMaxCode;
+            int lBitMask = bitMask;
+            int lOldCode = oldCode;
+            byte lFinChar = finChar;
+            int lStackP = stackP;
+            int lFreeEnt = freeEnt;
+            byte[] lData = data;
+            int lBitPos = bitPos;
+
+            // empty stack if stuff still left
+            int sSize = lStack.Length - lStackP;
+            if (sSize > 0)
+            {
+                int num = (sSize >= count) ? count : sSize;
+                Array.Copy(lStack, lStackP, buffer, offset, num);
+                offset += num;
+                count -= num;
+                lStackP += num;
+            }
+
+            if (count == 0)
+            {
+                stackP = lStackP;
+                return offset - start;
+            }
+
+            // loop, filling local buffer until enough data has been decompressed
+            MainLoop:
+            do
+            {
+                if (end < EXTRA)
+                {
+                    Fill();
+                }
+
+                int bitIn = (got > 0) ? (end - end % lNBits) << 3 : (end << 3) - (lNBits - 1);
+
+                while (lBitPos < bitIn)
+                {
+                    #region A
+
+                    // handle 1-byte reads correctly
+                    if (count == 0)
+                    {
+                        nBits = lNBits;
+                        maxCode = lMaxCode;
+                        maxMaxCode = lMaxMaxCode;
+                        bitMask = lBitMask;
+                        oldCode = lOldCode;
+                        finChar = lFinChar;
+                        stackP = lStackP;
+                        freeEnt = lFreeEnt;
+                        bitPos = lBitPos;
+
+                        return offset - start;
+                    }
+
+                    // check for code-width expansion
+                    if (lFreeEnt > lMaxCode)
+                    {
+                        int nBytes = lNBits << 3;
+                        lBitPos = (lBitPos - 1) + nBytes - (lBitPos - 1 + nBytes) % nBytes;
+
+                        lNBits++;
+                        lMaxCode = (lNBits == maxBits) ? lMaxMaxCode : (1 << lNBits) - 1;
+
+                        lBitMask = (1 << lNBits) - 1;
+                        lBitPos = ResetBuf(lBitPos);
+                        goto MainLoop;
+                    }
+
+                    #endregion A
+
+                    #region B
+
+                    // read next code
+                    int pos = lBitPos >> 3;
+                    int code =
+                        (
+                            (
+                                (lData[pos] & 0xFF)
+                                | ((lData[pos + 1] & 0xFF) << 8)
+                                | ((lData[pos + 2] & 0xFF) << 16)
+                            ) >> (lBitPos & 0x7)
+                        ) & lBitMask;
+
+                    lBitPos += lNBits;
+
+                    // handle first iteration
+                    if (lOldCode == -1)
+                    {
+                        if (code >= 256)
+                            throw new IncompleteArchiveException(
+                                "corrupt input: " + code + " > 255"
+                            );
+
+                        lFinChar = (byte)(lOldCode = code);
+                        buffer[offset++] = lFinChar;
+                        count--;
+                        continue;
+                    }
+
+                    // handle CLEAR code
+                    if (code == TBL_CLEAR && blockMode)
+                    {
+                        Array.Copy(zeros, 0, lTabPrefix, 0, zeros.Length);
+                        lFreeEnt = TBL_FIRST - 1;
+
+                        int nBytes = lNBits << 3;
+                        lBitPos = (lBitPos - 1) + nBytes - (lBitPos - 1 + nBytes) % nBytes;
+                        lNBits = LzwConstants.INIT_BITS;
+                        lMaxCode = (1 << lNBits) - 1;
+                        lBitMask = lMaxCode;
+
+                        // Code tables reset
+
+                        lBitPos = ResetBuf(lBitPos);
+                        goto MainLoop;
+                    }
+
+                    #endregion B
+
+                    #region C
+
+                    // setup
+                    int inCode = code;
+                    lStackP = lStack.Length;
+
+                    // Handle KwK case
+                    if (code >= lFreeEnt)
+                    {
+                        if (code > lFreeEnt)
+                        {
+                            throw new IncompleteArchiveException(
+                                "corrupt input: code=" + code + ", freeEnt=" + lFreeEnt
+                            );
+                        }
+
+                        lStack[--lStackP] = lFinChar;
+                        code = lOldCode;
+                    }
+
+                    // Generate output characters in reverse order
+                    while (code >= 256)
+                    {
+                        lStack[--lStackP] = lTabSuffix[code];
+                        code = lTabPrefix[code];
+                    }
+
+                    lFinChar = lTabSuffix[code];
+                    buffer[offset++] = lFinChar;
+                    count--;
+
+                    // And put them out in forward order
+                    sSize = lStack.Length - lStackP;
+                    int num = (sSize >= count) ? count : sSize;
+                    Array.Copy(lStack, lStackP, buffer, offset, num);
+                    offset += num;
+                    count -= num;
+                    lStackP += num;
+
+                    #endregion C
+
+                    #region D
+
+                    // generate new entry in table
+                    if (lFreeEnt < lMaxMaxCode)
+                    {
+                        lTabPrefix[lFreeEnt] = lOldCode;
+                        lTabSuffix[lFreeEnt] = lFinChar;
+                        lFreeEnt++;
+                    }
+
+                    // Remember previous code
+                    lOldCode = inCode;
+
+                    // if output buffer full, then return
+                    if (count == 0)
+                    {
+                        nBits = lNBits;
+                        maxCode = lMaxCode;
+                        bitMask = lBitMask;
+                        oldCode = lOldCode;
+                        finChar = lFinChar;
+                        stackP = lStackP;
+                        freeEnt = lFreeEnt;
+                        bitPos = lBitPos;
+
+                        return offset - start;
+                    }
+
+                    #endregion D
+                } // while
+
+                lBitPos = ResetBuf(lBitPos);
+            } while (got > 0); // do..while
+
+            nBits = lNBits;
+            maxCode = lMaxCode;
+            bitMask = lBitMask;
+            oldCode = lOldCode;
+            finChar = lFinChar;
+            stackP = lStackP;
+            freeEnt = lFreeEnt;
+            bitPos = lBitPos;
+
+            eof = true;
+            return offset - start;
+        }
+
+        /// <summary>
+        /// Moves the unread data in the buffer to the beginning and resets
+        /// the pointers.
+        /// </summary>
+        /// <param name="bitPosition"></param>
+        /// <returns></returns>
+        private int ResetBuf(int bitPosition)
+        {
+            int pos = bitPosition >> 3;
+            Array.Copy(data, pos, data, 0, end - pos);
+            end -= pos;
+            return 0;
+        }
+
+        private void Fill()
+        {
+            got = baseInputStream.Read(data, end, data.Length - 1 - end);
+            if (got > 0)
+            {
+                end += got;
+            }
+        }
+
+        private void ParseHeader()
+        {
+            headerParsed = true;
+
+            byte[] hdr = new byte[LzwConstants.HDR_SIZE];
+
+            int result = baseInputStream.Read(hdr, 0, hdr.Length);
+
+            // Check the magic marker
+            if (result < 0)
+                throw new IncompleteArchiveException("Failed to read LZW header");
+
+            if (hdr[0] != (LzwConstants.MAGIC >> 8) || hdr[1] != (LzwConstants.MAGIC & 0xff))
+            {
+                throw new IncompleteArchiveException(
+                    String.Format(
+                        "Wrong LZW header. Magic bytes don't match. 0x{0:x2} 0x{1:x2}",
+                        hdr[0],
+                        hdr[1]
+                    )
+                );
+            }
+
+            // Check the 3rd header byte
+            blockMode = (hdr[2] & LzwConstants.BLOCK_MODE_MASK) > 0;
+            maxBits = hdr[2] & LzwConstants.BIT_MASK;
+
+            if (maxBits > LzwConstants.MAX_BITS)
+            {
+                throw new ArchiveException(
+                    "Stream compressed with "
+                        + maxBits
+                        + " bits, but decompression can only handle "
+                        + LzwConstants.MAX_BITS
+                        + " bits."
+                );
+            }
+
+            if ((hdr[2] & LzwConstants.RESERVED_MASK) > 0)
+            {
+                throw new ArchiveException("Unsupported bits set in the header.");
+            }
+
+            // Initialize variables
+            maxMaxCode = 1 << maxBits;
+            nBits = LzwConstants.INIT_BITS;
+            maxCode = (1 << nBits) - 1;
+            bitMask = maxCode;
+            oldCode = -1;
+            finChar = 0;
+            freeEnt = blockMode ? TBL_FIRST : 256;
+
+            tabPrefix = new int[1 << maxBits];
+            tabSuffix = new byte[1 << maxBits];
+            stack = new byte[1 << maxBits];
+            stackP = stack.Length;
+
+            for (int idx = 255; idx >= 0; idx--)
+                tabSuffix[idx] = (byte)idx;
+        }
+
+        #region Stream Overrides
+
+        /// <summary>
+        /// Gets a value indicating whether the current stream supports reading
+        /// </summary>
+        public override bool CanRead
+        {
+            get { return baseInputStream.CanRead; }
+        }
+
+        /// <summary>
+        /// Gets a value of false indicating seeking is not supported for this stream.
+        /// </summary>
+        public override bool CanSeek
+        {
+            get { return false; }
+        }
+
+        /// <summary>
+        /// Gets a value of false indicating that this stream is not writeable.
+        /// </summary>
+        public override bool CanWrite
+        {
+            get { return false; }
+        }
+
+        /// <summary>
+        /// A value representing the length of the stream in bytes.
+        /// </summary>
+        public override long Length
+        {
+            get { return got; }
+        }
+
+        /// <summary>
+        /// The current position within the stream.
+        /// Throws a NotSupportedException when attempting to set the position
+        /// </summary>
+        /// <exception cref="NotSupportedException">Attempting to set the position</exception>
+        public override long Position
+        {
+            get { return baseInputStream.Position; }
+            set { throw new NotSupportedException("InflaterInputStream Position not supported"); }
+        }
+
+        /// <summary>
+        /// Flushes the baseInputStream
+        /// </summary>
+        public override void Flush()
+        {
+            baseInputStream.Flush();
+        }
+
+        /// <summary>
+        /// Sets the position within the current stream
+        /// Always throws a NotSupportedException
+        /// </summary>
+        /// <param name="offset">The relative offset to seek to.</param>
+        /// <param name="origin">The <see cref="SeekOrigin"/> defining where to seek from.</param>
+        /// <returns>The new position in the stream.</returns>
+        /// <exception cref="NotSupportedException">Any access</exception>
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new NotSupportedException("Seek not supported");
+        }
+
+        /// <summary>
+        /// Set the length of the current stream
+        /// Always throws a NotSupportedException
+        /// </summary>
+        /// <param name="value">The new length value for the stream.</param>
+        /// <exception cref="NotSupportedException">Any access</exception>
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException("InflaterInputStream SetLength not supported");
+        }
+
+        /// <summary>
+        /// Writes a sequence of bytes to stream and advances the current position
+        /// This method always throws a NotSupportedException
+        /// </summary>
+        /// <param name="buffer">The buffer containing data to write.</param>
+        /// <param name="offset">The offset of the first byte to write.</param>
+        /// <param name="count">The number of bytes to write.</param>
+        /// <exception cref="NotSupportedException">Any access</exception>
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            throw new NotSupportedException("InflaterInputStream Write not supported");
+        }
+
+        /// <summary>
+        /// Writes one byte to the current stream and advances the current position
+        /// Always throws a NotSupportedException
+        /// </summary>
+        /// <param name="value">The byte to write.</param>
+        /// <exception cref="NotSupportedException">Any access</exception>
+        public override void WriteByte(byte value)
+        {
+            throw new NotSupportedException("InflaterInputStream WriteByte not supported");
+        }
+
+        /// <summary>
+        /// Closes the input stream.  When <see cref="IsStreamOwner"></see>
+        /// is true the underlying stream is also closed.
+        /// </summary>
+        protected override void Dispose(bool disposing)
+        {
+            if (!isClosed)
+            {
+                isClosed = true;
+                if (IsStreamOwner)
+                {
+                    baseInputStream.Dispose();
+                }
+            }
+        }
+
+        #endregion Stream Overrides
+
+        #region Instance Fields
+
+        private Stream baseInputStream;
+
+        /// <summary>
+        /// Flag indicating wether this instance has been closed or not.
+        /// </summary>
+        private bool isClosed;
+
+        private readonly byte[] one = new byte[1];
+        private bool headerParsed;
+
+        // string table stuff
+        private const int TBL_CLEAR = 0x100;
+
+        private const int TBL_FIRST = TBL_CLEAR + 1;
+
+        private int[] tabPrefix = new int[0]; //
+        private byte[] tabSuffix = new byte[0]; //
+        private readonly int[] zeros = new int[256];
+        private byte[] stack = new byte[0]; //
+
+        // various state
+        private bool blockMode;
+
+        private int nBits;
+        private int maxBits;
+        private int maxMaxCode;
+        private int maxCode;
+        private int bitMask;
+        private int oldCode;
+        private byte finChar;
+        private int stackP;
+        private int freeEnt;
+
+        // input buffer
+        private readonly byte[] data = new byte[1024 * 8];
+
+        private int bitPos;
+        private int end;
+        private int got;
+        private bool eof;
+        private const int EXTRA = 64;
+
+        #endregion Instance Fields
+    }
+}

src/SharpCompress/Compressors/PPMd/H/ModelPPM.cs

@@ -22,7 +22,7 @@ internal class ModelPpm
         }
     }
 
-    public SubAllocator SubAlloc { get; } = new SubAllocator();
+    public SubAllocator SubAlloc { get; } = new();
 
     public virtual See2Context DummySee2Cont => _dummySee2Cont;
 
@@ -137,34 +137,34 @@ internal class ModelPpm
 
     // Temp fields
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState1 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState1 = new State(null);
+    private readonly State _tempState1 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState2 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState2 = new State(null);
+    private readonly State _tempState2 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState3 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState3 = new State(null);
+    private readonly State _tempState3 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState4 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState4 = new State(null);
+    private readonly State _tempState4 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempStateRef1 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly StateRef _tempStateRef1 = new StateRef();
+    private readonly StateRef _tempStateRef1 = new();
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempStateRef2 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly StateRef _tempStateRef2 = new StateRef();
+    private readonly StateRef _tempStateRef2 = new();
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempPPMContext1 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly PpmContext _tempPpmContext1 = new PpmContext(null);
+    private readonly PpmContext _tempPpmContext1 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempPPMContext2 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly PpmContext _tempPpmContext2 = new PpmContext(null);
+    private readonly PpmContext _tempPpmContext2 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempPPMContext3 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly PpmContext _tempPpmContext3 = new PpmContext(null);
+    private readonly PpmContext _tempPpmContext3 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempPPMContext4 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly PpmContext _tempPpmContext4 = new PpmContext(null);
+    private readonly PpmContext _tempPpmContext4 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'ps '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
     private readonly int[] _ps = new int[MAX_O];

src/SharpCompress/Compressors/PPMd/H/PPMContext.cs

@@ -64,19 +64,19 @@ internal class PpmContext : Pointer
 
     // Temp fields
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState1 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState1 = new State(null);
+    private readonly State _tempState1 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState2 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState2 = new State(null);
+    private readonly State _tempState2 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState3 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState3 = new State(null);
+    private readonly State _tempState3 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState4 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState4 = new State(null);
+    private readonly State _tempState4 = new(null);
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'tempState5 '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
-    private readonly State _tempState5 = new State(null);
+    private readonly State _tempState5 = new(null);
     private PpmContext _tempPpmContext;
 
     //UPGRADE_NOTE: Final was removed from the declaration of 'ps '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"

src/SharpCompress/Compressors/PPMd/I1/Allocator.cs

@@ -395,10 +395,8 @@ internal class Allocator
             unitCountDifference -= unitCount;
         }
 
-        _memoryNodes[UNITS_TO_INDEX[unitCountDifference - 1]].Insert(
-            newPointer,
-            unitCountDifference
-        );
+        _memoryNodes[UNITS_TO_INDEX[unitCountDifference - 1]]
+            .Insert(newPointer, unitCountDifference);
     }
 
     private void GlueFreeBlocks()
@@ -457,10 +455,11 @@ internal class Allocator
                 if (INDEX_TO_UNITS[index] != unitCount)
                 {
                     var unitCountDifference = unitCount - INDEX_TO_UNITS[--index];
-                    _memoryNodes[unitCountDifference - 1].Insert(
-                        memoryNode0 + (unitCount - unitCountDifference),
-                        unitCountDifference
-                    );
+                    _memoryNodes[unitCountDifference - 1]
+                        .Insert(
+                            memoryNode0 + (unitCount - unitCountDifference),
+                            unitCountDifference
+                        );
                 }
 
                 _memoryNodes[index].Insert(memoryNode0, INDEX_TO_UNITS[index]);

src/SharpCompress/Compressors/PPMd/I1/MemoryNode.cs

@@ -27,7 +27,7 @@ internal struct MemoryNode
 {
     public uint _address;
     public byte[] _memory;
-    public static readonly MemoryNode ZERO = new MemoryNode(0, null);
+    public static readonly MemoryNode ZERO = new(0, null);
     public const int SIZE = 12;
 
     /// <summary>
@@ -64,7 +64,7 @@ internal struct MemoryNode
     public MemoryNode Next
     {
         get =>
-            new MemoryNode(
+            new(
                 _memory[_address + 4]
                     | (((uint)_memory[_address + 5]) << 8)
                     | (((uint)_memory[_address + 6]) << 16)
@@ -150,7 +150,7 @@ internal struct MemoryNode
     /// <param name="pointer"></param>
     /// <returns></returns>
     public static implicit operator MemoryNode(Pointer pointer) =>
-        new MemoryNode(pointer._address, pointer._memory);
+        new(pointer._address, pointer._memory);
 
     /// <summary>
     /// Allow pointer-like addition on a memory node.

src/SharpCompress/Compressors/PPMd/I1/Model.cs

@@ -866,7 +866,8 @@ internal partial class Model
                 );
             }
             else if (
-                (currentContext.SummaryFrequency += 4) > 128 + (4 * currentContext.NumberStatistics)
+                (currentContext.SummaryFrequency += 4)
+                > 128 + (4 * currentContext.NumberStatistics)
             )
             {
                 Refresh((uint)((currentContext.NumberStatistics + 2) >> 1), true, currentContext);

src/SharpCompress/Compressors/PPMd/I1/Pointer.cs

@@ -22,7 +22,7 @@ internal struct Pointer
 {
     public uint _address;
     public byte[] _memory;
-    public static readonly Pointer ZERO = new Pointer(0, null);
+    public static readonly Pointer ZERO = new(0, null);
     public const int SIZE = 1;
 
     /// <summary>
@@ -69,7 +69,7 @@ internal struct Pointer
     /// <param name="memoryNode"></param>
     /// <returns></returns>
     public static implicit operator Pointer(MemoryNode memoryNode) =>
-        new Pointer(memoryNode._address, memoryNode._memory);
+        new(memoryNode._address, memoryNode._memory);
 
     /// <summary>
     /// Allow a <see cref="Model.PpmContext"/> to be implicitly converted to a <see cref="Pointer"/>.
@@ -77,15 +77,14 @@ internal struct Pointer
     /// <param name="context"></param>
     /// <returns></returns>
     public static implicit operator Pointer(Model.PpmContext context) =>
-        new Pointer(context._address, context._memory);
+        new(context._address, context._memory);
 
     /// <summary>
     /// Allow a <see cref="PpmState"/> to be implicitly converted to a <see cref="Pointer"/>.
     /// </summary>
     /// <param name="state"></param>
     /// <returns></returns>
-    public static implicit operator Pointer(PpmState state) =>
-        new Pointer(state._address, state._memory);
+    public static implicit operator Pointer(PpmState state) => new(state._address, state._memory);
 
     /// <summary>
     /// Increase the address of a pointer by the given number of bytes.

src/SharpCompress/Compressors/PPMd/I1/PpmContext.cs

@@ -21,7 +21,7 @@ internal partial class Model
     {
         public uint _address;
         public byte[] _memory;
-        public static readonly PpmContext ZERO = new PpmContext(0, null);
+        public static readonly PpmContext ZERO = new(0, null);
         public const int SIZE = 12;
 
         /// <summary>
@@ -70,7 +70,7 @@ internal partial class Model
         public PpmState Statistics
         {
             get =>
-                new PpmState(
+                new(
                     _memory[_address + 4]
                         | (((uint)_memory[_address + 5]) << 8)
                         | (((uint)_memory[_address + 6]) << 16)
@@ -92,7 +92,7 @@ internal partial class Model
         public PpmContext Suffix
         {
             get =>
-                new PpmContext(
+                new(
                     _memory[_address + 8]
                         | (((uint)_memory[_address + 9]) << 8)
                         | (((uint)_memory[_address + 10]) << 16)
@@ -133,7 +133,7 @@ internal partial class Model
         /// </para>
         /// </remarks>
         /// <returns></returns>
-        public PpmState FirstState => new PpmState(_address + 2, _memory);
+        public PpmState FirstState => new(_address + 2, _memory);
 
         /// <summary>
         /// Gets or sets the symbol of the first PPM state.  This is provided for convenience.  The same
@@ -164,7 +164,7 @@ internal partial class Model
         public PpmContext FirstStateSuccessor
         {
             get =>
-                new PpmContext(
+                new(
                     _memory[_address + 4]
                         | (((uint)_memory[_address + 5]) << 8)
                         | (((uint)_memory[_address + 6]) << 16)
@@ -186,7 +186,7 @@ internal partial class Model
         /// <param name="pointer"></param>
         /// <returns></returns>
         public static implicit operator PpmContext(Pointer pointer) =>
-            new PpmContext(pointer._address, pointer._memory);
+            new(pointer._address, pointer._memory);
 
         /// <summary>
         /// Allow pointer-like addition on a PPM context.

src/SharpCompress/Compressors/PPMd/I1/PpmState.cs

@@ -19,7 +19,7 @@ internal struct PpmState
 {
     public uint _address;
     public byte[] _memory;
-    public static readonly PpmState ZERO = new PpmState(0, null);
+    public static readonly PpmState ZERO = new(0, null);
     public const int SIZE = 6;
 
     /// <summary>
@@ -55,7 +55,7 @@ internal struct PpmState
     public Model.PpmContext Successor
     {
         get =>
-            new Model.PpmContext(
+            new(
                 _memory[_address + 2]
                     | (((uint)_memory[_address + 3]) << 8)
                     | (((uint)_memory[_address + 4]) << 16)
@@ -77,7 +77,7 @@ internal struct PpmState
     /// </summary>
     /// <param name="offset"></param>
     /// <returns></returns>
-    public PpmState this[int offset] => new PpmState((uint)(_address + (offset * SIZE)), _memory);
+    public PpmState this[int offset] => new((uint)(_address + (offset * SIZE)), _memory);
 
     /// <summary>
     /// Allow a pointer to be implicitly converted to a PPM state.
@@ -85,7 +85,7 @@ internal struct PpmState
     /// <param name="pointer"></param>
     /// <returns></returns>
     public static implicit operator PpmState(Pointer pointer) =>
-        new PpmState(pointer._address, pointer._memory);
+        new(pointer._address, pointer._memory);
 
     /// <summary>
     /// Allow pointer-like addition on a PPM state.

src/SharpCompress/Compressors/Rar/MultiVolumeReadOnlyStream.cs

@@ -128,9 +128,9 @@ internal sealed class MultiVolumeReadOnlyStream : Stream
 
     public override bool CanWrite => false;
 
-    public uint CurrentCrc { get; private set; }
+    public byte[] CurrentCrc { get; private set; }
 
-    public override void Flush() => throw new NotSupportedException();
+    public override void Flush() { }
 
     public override long Length => throw new NotSupportedException();
 

src/SharpCompress/Compressors/Rar/RarBLAKE2spStream.cs

@@ -0,0 +1,305 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using SharpCompress.Common;
+using SharpCompress.Common.Rar.Headers;
+
+namespace SharpCompress.Compressors.Rar;
+
+internal class RarBLAKE2spStream : RarStream
+{
+    private readonly MultiVolumeReadOnlyStream readStream;
+    private readonly bool disableCRCCheck;
+
+    const uint BLAKE2S_NUM_ROUNDS = 10;
+    const uint BLAKE2S_FINAL_FLAG = (~(uint)0);
+    const int BLAKE2S_BLOCK_SIZE = 64;
+    const int BLAKE2S_DIGEST_SIZE = 32;
+    const int BLAKE2SP_PARALLEL_DEGREE = 8;
+    const uint BLAKE2S_INIT_IV_SIZE = 8;
+
+    static readonly UInt32[] k_BLAKE2S_IV =
+    {
+        0x6A09E667U,
+        0xBB67AE85U,
+        0x3C6EF372U,
+        0xA54FF53AU,
+        0x510E527FU,
+        0x9B05688CU,
+        0x1F83D9ABU,
+        0x5BE0CD19U
+    };
+
+    static readonly byte[][] k_BLAKE2S_Sigma =
+    {
+        new byte[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
+        new byte[] { 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 },
+        new byte[] { 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
+        new byte[] { 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
+        new byte[] { 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
+        new byte[] { 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
+        new byte[] { 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
+        new byte[] { 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
+        new byte[] { 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
+        new byte[] { 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
+    };
+
+    internal class BLAKE2S
+    {
+        internal UInt32[] h;
+        internal UInt32[] t;
+        internal UInt32[] f;
+        internal byte[] b;
+        internal int bufferPosition;
+        internal UInt32 lastNodeFlag;
+        UInt32[] dummy;
+
+        public BLAKE2S()
+        {
+            h = new uint[BLAKE2S_INIT_IV_SIZE];
+            t = new uint[2];
+            f = new uint[2];
+            b = new byte[BLAKE2S_BLOCK_SIZE];
+            dummy = new uint[2];
+        }
+    };
+
+    internal class BLAKE2SP
+    {
+        internal BLAKE2S[] S;
+        internal int bufferPosition;
+
+        public BLAKE2SP()
+        {
+            S = new BLAKE2S[BLAKE2SP_PARALLEL_DEGREE];
+            for (var i = 0; i < S.Length; i++)
+            {
+                S[i] = new BLAKE2S();
+            }
+        }
+    };
+
+    BLAKE2SP _blake2sp;
+
+    byte[] _hash = { };
+
+    public RarBLAKE2spStream(
+        IRarUnpack unpack,
+        FileHeader fileHeader,
+        MultiVolumeReadOnlyStream readStream
+    )
+        : base(unpack, fileHeader, readStream)
+    {
+        this.readStream = readStream;
+        disableCRCCheck = fileHeader.IsEncrypted;
+        _hash = fileHeader.FileCrc;
+        _blake2sp = new BLAKE2SP();
+        ResetCrc();
+    }
+
+    public byte[] GetCrc() => _hash;
+
+    internal void ResetCrc(BLAKE2S hash)
+    {
+        for (UInt32 j = 0; j < BLAKE2S_INIT_IV_SIZE; j++)
+        {
+            hash.h[j] = k_BLAKE2S_IV[j];
+        }
+        hash.t[0] = 0;
+        hash.t[1] = 0;
+        hash.f[0] = 0;
+        hash.f[1] = 0;
+        hash.bufferPosition = 0;
+        hash.lastNodeFlag = 0;
+    }
+
+    internal void G(
+        ref UInt32[] m,
+        ref byte[] sigma,
+        int i,
+        ref UInt32 a,
+        ref UInt32 b,
+        ref UInt32 c,
+        ref UInt32 d
+    )
+    {
+        a += b + m[sigma[2 * i]];
+        d ^= a;
+        d = (d >> 16) | (d << 16);
+        c += d;
+        b ^= c;
+        b = (b >> 12) | (b << 20);
+
+        a += b + m[sigma[2 * i + 1]];
+        d ^= a;
+        d = (d >> 8) | (d << 24);
+        c += d;
+        b ^= c;
+        b = (b >> 7) | (b << 25);
+    }
+
+    internal void Compress(BLAKE2S hash)
+    {
+        var m = new UInt32[16];
+        var v = new UInt32[16];
+
+        for (var i = 0; i < 16; i++)
+        {
+            m[i] = BitConverter.ToUInt32(hash.b, i * 4);
+        }
+
+        for (var i = 0; i < 8; i++)
+        {
+            v[i] = hash.h[i];
+        }
+
+        v[8] = k_BLAKE2S_IV[0];
+        v[9] = k_BLAKE2S_IV[1];
+        v[10] = k_BLAKE2S_IV[2];
+        v[11] = k_BLAKE2S_IV[3];
+
+        v[12] = hash.t[0] ^ k_BLAKE2S_IV[4];
+        v[13] = hash.t[1] ^ k_BLAKE2S_IV[5];
+        v[14] = hash.f[0] ^ k_BLAKE2S_IV[6];
+        v[15] = hash.f[1] ^ k_BLAKE2S_IV[7];
+
+        for (var r = 0; r < BLAKE2S_NUM_ROUNDS; r++)
+        {
+            ref byte[] sigma = ref k_BLAKE2S_Sigma[r];
+
+            G(ref m, ref sigma, 0, ref v[0], ref v[4], ref v[8], ref v[12]);
+            G(ref m, ref sigma, 1, ref v[1], ref v[5], ref v[9], ref v[13]);
+            G(ref m, ref sigma, 2, ref v[2], ref v[6], ref v[10], ref v[14]);
+            G(ref m, ref sigma, 3, ref v[3], ref v[7], ref v[11], ref v[15]);
+            G(ref m, ref sigma, 4, ref v[0], ref v[5], ref v[10], ref v[15]);
+            G(ref m, ref sigma, 5, ref v[1], ref v[6], ref v[11], ref v[12]);
+            G(ref m, ref sigma, 6, ref v[2], ref v[7], ref v[8], ref v[13]);
+            G(ref m, ref sigma, 7, ref v[3], ref v[4], ref v[9], ref v[14]);
+        }
+
+        for (var i = 0; i < 8; i++)
+        {
+            hash.h[i] ^= v[i] ^ v[i + 8];
+        }
+    }
+
+    internal void Update(BLAKE2S hash, ReadOnlySpan<byte> data, int size)
+    {
+        var i = 0;
+        while (size != 0)
+        {
+            var pos = hash.bufferPosition;
+            var reminder = BLAKE2S_BLOCK_SIZE - pos;
+
+            if (size <= reminder)
+            {
+                data.Slice(i, size).CopyTo(new Span<byte>(hash.b, pos, size));
+                hash.bufferPosition += size;
+                return;
+            }
+            data.Slice(i, reminder).CopyTo(new Span<byte>(hash.b, pos, reminder));
+            hash.t[0] += BLAKE2S_BLOCK_SIZE;
+            hash.t[1] += hash.t[0] < BLAKE2S_BLOCK_SIZE ? 1U : 0U;
+            Compress(hash);
+            hash.bufferPosition = 0;
+            i += reminder;
+            size -= reminder;
+        }
+    }
+
+    internal byte[] Final(BLAKE2S hash)
+    {
+        hash.t[0] += (uint)hash.bufferPosition;
+        hash.t[1] += hash.t[0] < hash.bufferPosition ? 1U : 0U;
+        hash.f[0] = BLAKE2S_FINAL_FLAG;
+        hash.f[1] = hash.lastNodeFlag;
+        Array.Clear(hash.b, hash.bufferPosition, BLAKE2S_BLOCK_SIZE - hash.bufferPosition);
+        Compress(hash);
+
+        var mem = new MemoryStream();
+
+        for (var i = 0; i < 8; i++)
+        {
+            mem.Write(BitConverter.GetBytes(hash.h[i]), 0, 4);
+        }
+
+        return mem.ToArray();
+    }
+
+    public void ResetCrc()
+    {
+        _blake2sp.bufferPosition = 0;
+
+        for (UInt32 i = 0; i < BLAKE2SP_PARALLEL_DEGREE; i++)
+        {
+            _blake2sp.S[i].bufferPosition = 0;
+            ResetCrc(_blake2sp.S[i]);
+            _blake2sp.S[i].h[0] ^= (BLAKE2S_DIGEST_SIZE | BLAKE2SP_PARALLEL_DEGREE << 16 | 2 << 24);
+            _blake2sp.S[i].h[2] ^= i;
+            _blake2sp.S[i].h[3] ^= (BLAKE2S_DIGEST_SIZE << 24);
+        }
+
+        _blake2sp.S[BLAKE2SP_PARALLEL_DEGREE - 1].lastNodeFlag = BLAKE2S_FINAL_FLAG;
+    }
+
+    internal void Update(BLAKE2SP hash, ReadOnlySpan<byte> data, int size)
+    {
+        var i = 0;
+        var pos = hash.bufferPosition;
+        while (size != 0)
+        {
+            var index = pos / BLAKE2S_BLOCK_SIZE;
+            var reminder = BLAKE2S_BLOCK_SIZE - (pos & (BLAKE2S_BLOCK_SIZE - 1));
+            if (reminder > size)
+            {
+                reminder = size;
+            }
+            //            Update(hash.S[index], data, size);
+            Update(hash.S[index], data.Slice(i, reminder), reminder);
+            size -= reminder;
+            i += reminder;
+            pos += reminder;
+            pos &= (BLAKE2S_BLOCK_SIZE * (BLAKE2SP_PARALLEL_DEGREE - 1));
+        }
+        hash.bufferPosition = pos;
+    }
+
+    internal byte[] Final(BLAKE2SP hash)
+    {
+        var h = new BLAKE2S();
+
+        ResetCrc(h);
+        h.h[0] ^= (BLAKE2S_DIGEST_SIZE | BLAKE2SP_PARALLEL_DEGREE << 16 | 2 << 24);
+        h.h[3] ^= (1 << 16 | BLAKE2S_DIGEST_SIZE << 24);
+        h.lastNodeFlag = BLAKE2S_FINAL_FLAG;
+
+        for (var i = 0; i < BLAKE2SP_PARALLEL_DEGREE; i++)
+        {
+            var digest = Final(_blake2sp.S[i]);
+            Update(h, digest, BLAKE2S_DIGEST_SIZE);
+        }
+
+        return Final(h);
+    }
+
+    public override int Read(byte[] buffer, int offset, int count)
+    {
+        var result = base.Read(buffer, offset, count);
+        if (result != 0)
+        {
+            Update(_blake2sp, new ReadOnlySpan<byte>(buffer, offset, result), result);
+        }
+        else
+        {
+            _hash = Final(_blake2sp);
+            if (!disableCRCCheck && !(GetCrc().SequenceEqual(readStream.CurrentCrc)) && count != 0)
+            {
+                // NOTE: we use the last FileHeader in a multipart volume to check CRC
+                throw new InvalidFormatException("file crc mismatch");
+            }
+        }
+
+        return result;
+    }
+}

src/SharpCompress/Compressors/Rar/RarCrcStream.cs

@@ -1,3 +1,4 @@
+using System;
 using SharpCompress.Common;
 using SharpCompress.Common.Rar.Headers;
 
@@ -7,6 +8,7 @@ internal class RarCrcStream : RarStream
 {
     private readonly MultiVolumeReadOnlyStream readStream;
     private uint currentCrc;
+    private readonly bool disableCRC;
 
     public RarCrcStream(
         IRarUnpack unpack,
@@ -16,6 +18,7 @@ internal class RarCrcStream : RarStream
         : base(unpack, fileHeader, readStream)
     {
         this.readStream = readStream;
+        disableCRC = fileHeader.IsEncrypted;
         ResetCrc();
     }
 
@@ -30,7 +33,11 @@ internal class RarCrcStream : RarStream
         {
             currentCrc = RarCRC.CheckCrc(currentCrc, buffer, offset, result);
         }
-        else if (GetCrc() != readStream.CurrentCrc && count != 0)
+        else if (
+            !disableCRC
+            && GetCrc() != BitConverter.ToUInt32(readStream.CurrentCrc, 0)
+            && count != 0
+        )
         {
             // NOTE: we use the last FileHeader in a multipart volume to check CRC
             throw new InvalidFormatException("file crc mismatch");

src/SharpCompress/Compressors/Rar/RarStream.cs

@@ -14,7 +14,7 @@ internal class RarStream : Stream
 
     private bool fetch;
 
-    private byte[] tmpBuffer = new byte[65536];
+    private byte[] tmpBuffer = BufferPool.Rent(65536);
     private int tmpOffset;
     private int tmpCount;
 
@@ -40,6 +40,11 @@ internal class RarStream : Stream
     {
         if (!isDisposed)
         {
+            if (disposing)
+            {
+                BufferPool.Return(this.tmpBuffer);
+                this.tmpBuffer = null;
+            }
             isDisposed = true;
             base.Dispose(disposing);
             readStream.Dispose();
@@ -86,6 +91,13 @@ internal class RarStream : Stream
             fetch = false;
         }
         _position += outTotal;
+        if (count > 0 && outTotal == 0 && _position != Length)
+        {
+            // sanity check, eg if we try to decompress a redir entry
+            throw new InvalidOperationException(
+                $"unpacked file size does not match header: expected {Length} found {_position}"
+            );
+        }
         return outTotal;
     }
 
@@ -111,16 +123,7 @@ internal class RarStream : Stream
         }
         if (count > 0)
         {
-            if (tmpBuffer.Length < tmpCount + count)
-            {
-                var newBuffer = new byte[
-                    tmpBuffer.Length * 2 > tmpCount + count
-                        ? tmpBuffer.Length * 2
-                        : tmpCount + count
-                ];
-                Buffer.BlockCopy(tmpBuffer, 0, newBuffer, 0, tmpCount);
-                tmpBuffer = newBuffer;
-            }
+            EnsureBufferCapacity(count);
             Buffer.BlockCopy(buffer, offset, tmpBuffer, tmpCount, count);
             tmpCount += count;
             tmpOffset = 0;
@@ -131,4 +134,20 @@ internal class RarStream : Stream
             unpack.Suspended = false;
         }
     }
+
+    private void EnsureBufferCapacity(int count)
+    {
+        if (this.tmpBuffer.Length < this.tmpCount + count)
+        {
+            var newLength =
+                this.tmpBuffer.Length * 2 > this.tmpCount + count
+                    ? this.tmpBuffer.Length * 2
+                    : this.tmpCount + count;
+            var newBuffer = BufferPool.Rent(newLength);
+            Buffer.BlockCopy(this.tmpBuffer, 0, newBuffer, 0, this.tmpCount);
+            var oldBuffer = this.tmpBuffer;
+            this.tmpBuffer = newBuffer;
+            BufferPool.Return(oldBuffer);
+        }
+    }
 }

src/SharpCompress/Compressors/Rar/UnpackV1/Unpack.cs

@@ -52,19 +52,19 @@ internal sealed partial class Unpack : BitInput, IRarUnpack
 
     public int PpmEscChar { get; set; }
 
-    private readonly ModelPpm ppm = new ModelPpm();
+    private readonly ModelPpm ppm = new();
 
-    private readonly RarVM rarVM = new RarVM();
+    private readonly RarVM rarVM = new();
 
     // Filters code, one entry per filter
-    private readonly List<UnpackFilter> filters = new List<UnpackFilter>();
+    private readonly List<UnpackFilter> filters = new();
 
     // Filters stack, several entrances of same filter are possible
-    private readonly List<UnpackFilter> prgStack = new List<UnpackFilter>();
+    private readonly List<UnpackFilter> prgStack = new();
 
     // lengths of preceding blocks, one length per filter. Used to reduce size
     // required to write block length if lengths are repeating
-    private readonly List<int> oldFilterLengths = new List<int>();
+    private readonly List<int> oldFilterLengths = new();
 
     private int lastFilter;
 

src/SharpCompress/Compressors/Rar/UnpackV1/Unpack20.cs

@@ -25,15 +25,15 @@ internal partial class Unpack
 
     private readonly AudioVariables[] AudV = new AudioVariables[4];
 
-    private readonly LitDecode LD = new LitDecode();
+    private readonly LitDecode LD = new();
 
-    private readonly DistDecode DD = new DistDecode();
+    private readonly DistDecode DD = new();
 
-    private readonly LowDistDecode LDD = new LowDistDecode();
+    private readonly LowDistDecode LDD = new();
 
-    private readonly RepDecode RD = new RepDecode();
+    private readonly RepDecode RD = new();
 
-    private readonly BitDecode BD = new BitDecode();
+    private readonly BitDecode BD = new();
 
     private static readonly int[] LDecode =
     {

src/SharpCompress/Compressors/Rar/UnpackV1/UnpackUtility.cs

@@ -1,5 +1,4 @@
 using System;
-
 using SharpCompress.Compressors.Rar.VM;
 
 namespace SharpCompress.Compressors.Rar.UnpackV1;