Add memory state manager

Examples/ConsoleApp/Program.cs

@@ -26,13 +26,16 @@ static async Task Main()
 #pragma warning restore IL2026 // Members annotated with 'RequiresUnreferencedCodeAttribute' require dynamic access otherwise can break functionality when trimming application code
             Console.WriteLine($"Created by CryptoConfig('XMSS'): {alg is not null}");
         }
+
+        var message = new byte[] { 1, 2, 3 };
+        byte[] signature;
+        string publicKeyPem;
+
         {
             Console.WriteLine("Generating new key...");
 
-            var stateManager = new XmssFileStateManager(@"C:\test");
-            stateManager.DeleteAll();
             using var xmss = new Xmss();
-            xmss.GeneratePrivateKey(stateManager, XmssParameterSet.XMSS_SHA2_10_256, false);
+            xmss.GeneratePrivateKey(new XmssEphemeralStateManager(), XmssParameterSet.XMSS_SHA2_10_256, false);
             {
                 // this is special for XMSS, a long-running (cancelable) process
 
@@ -63,19 +66,13 @@ await xmss.CalculatePublicKeyAsync(progress =>
                 }
             }
             Console.WriteLine();
+
+            publicKeyPem = xmss.ExportSubjectPublicKeyInfoPem();
             Console.WriteLine("Public Key:");
-            Console.WriteLine(xmss.ExportSubjectPublicKeyInfoPem());
-        }
-        var message = new byte[] { 1, 2, 3 };
-        byte[] signature;
-        string publicKeyPem;
-        {
-            Console.WriteLine("Signing a message...");
+            Console.WriteLine(publicKeyPem);
 
-            using var xmss = new Xmss();
-            xmss.ImportPrivateKey(new XmssFileStateManager(@"C:\test"));
+            Console.WriteLine("Signing a message...");
             signature = xmss.Sign(message);
-            publicKeyPem = xmss.ExportSubjectPublicKeyInfoPem();
         }
         {
             using var xmss = new Xmss();

UnitTests/UnitTests/MemoryStateManager.cs

@@ -53,7 +53,7 @@ public void StoreStatefulPart(ReadOnlySpan<byte> expected, ReadOnlySpan<byte> da
 
         if (State[XmssKeyPart.PrivateStateful] is not byte[] oldData)
         {
-            throw new InvalidOperationException("Part does not exists.");
+            throw new InvalidOperationException("Part does not exist.");
         }
         if (!expected.SequenceEqual(oldData))
         {
@@ -68,7 +68,7 @@ public void Load(XmssKeyPart part, Span<byte> destination)
 
         if (State[part] is not byte[] data)
         {
-            throw new ArgumentException("Part does not exist.", nameof(part));
+            throw new InvalidOperationException("Part does not exist.");
         }
         if (data.Length != destination.Length)
         {

UnitTests/UnitTests/XmssMemoryStateManagerTests.cs

@@ -0,0 +1,185 @@
+// SPDX-FileCopyrightText: 2025 Frans van Dorsselaer
+//
+// SPDX-License-Identifier: MIT
+
+using Dorssel.Security.Cryptography;
+
+namespace UnitTests;
+
+[TestClass]
+sealed class XmssMemoryStateManagerTests
+{
+    [TestMethod]
+    public void Constructor()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+    }
+
+    [TestMethod]
+    public void Store()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+
+        stateManager.Store(XmssKeyPart.Public, [1]);
+    }
+
+    [TestMethod]
+    public void Store_Exists()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+
+        stateManager.Store(XmssKeyPart.Public, [1]);
+
+        Assert.ThrowsException<InvalidOperationException>(() =>
+        {
+            stateManager.Store(XmssKeyPart.Public, [2]);
+        });
+    }
+
+    [TestMethod]
+    public void StoreStoreStatefulPart()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.PrivateStateful, [1]);
+
+        stateManager.StoreStatefulPart([1], [2]);
+    }
+
+    [TestMethod]
+    public void StoreStoreStatefulPart_ExpectedAndDataMismatch()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.PrivateStateful, [1]);
+
+        Assert.ThrowsException<ArgumentException>(() =>
+        {
+            stateManager.StoreStatefulPart([1], [2, 3]);
+        });
+    }
+
+    [TestMethod]
+    public void StoreStoreStatefulPart_FileNotExists()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+
+        Assert.ThrowsException<InvalidOperationException>(() =>
+        {
+            stateManager.StoreStatefulPart([1], [2]);
+        });
+    }
+
+    [TestMethod]
+    public void StoreStoreStatefulPart_FileSizeMismatch()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.PrivateStateful, [1]);
+
+        Assert.ThrowsException<ArgumentException>(() =>
+        {
+            stateManager.StoreStatefulPart([1, 2], [3, 4]);
+        });
+    }
+
+    [TestMethod]
+    public void StoreStoreStatefulPart_FileContentMismatch()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.PrivateStateful, [1]);
+
+        Assert.ThrowsException<ArgumentException>(() =>
+        {
+            stateManager.StoreStatefulPart([2], [3]);
+        });
+    }
+
+    [TestMethod]
+    public void Load()
+    {
+        var data = new byte[] { 1, 2, 3 };
+
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.Public, data);
+
+        var read = new byte[data.Length];
+        stateManager.Load(XmssKeyPart.Public, read);
+
+        CollectionAssert.AreEqual(data, read);
+    }
+
+    [TestMethod]
+    public void Load_WrongSize()
+    {
+        var data = new byte[] { 1, 2, 3 };
+
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.Public, data);
+
+        var read = new byte[data.Length - 1];
+        Assert.ThrowsException<ArgumentException>(() =>
+        {
+            stateManager.Load(XmssKeyPart.Public, read);
+        });
+    }
+
+    [TestMethod]
+    public void Load_PartNotExists()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+
+        Assert.ThrowsException<InvalidOperationException>(() =>
+        {
+            stateManager.Load(XmssKeyPart.Public, new byte[1]);
+        });
+    }
+
+    [TestMethod]
+    public void Load_UnknownPart()
+    {
+        var data = new byte[] { 1, 2, 3 };
+
+        using var stateManager = new XmssMemoryStateManager();
+
+        Assert.ThrowsException<ArgumentOutOfRangeException>(() =>
+        {
+            stateManager.Load(Enum.GetValues<XmssKeyPart>().Max() + 1, new byte[1]);
+        });
+    }
+
+    [TestMethod]
+    public void DeletePublicPart()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.Public, [1]);
+
+        stateManager.DeletePublicPart();
+
+
+    }
+
+    [TestMethod]
+    public void DeletePublicPart_PartNotExists()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+
+        stateManager.DeletePublicPart();
+    }
+
+    [TestMethod]
+    public void DeleteAll()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+        stateManager.Store(XmssKeyPart.PrivateStateless, [1]);
+        stateManager.Store(XmssKeyPart.PrivateStateful, [2]);
+        stateManager.Store(XmssKeyPart.Public, [3]);
+
+        stateManager.DeleteAll();
+    }
+
+    [TestMethod]
+    public void DeleteAll_PartsNotExist()
+    {
+        using var stateManager = new XmssMemoryStateManager();
+
+        stateManager.DeleteAll();
+    }
+}

Xmss/XmssMemoryStateManager.cs

@@ -0,0 +1,134 @@
+// SPDX-FileCopyrightText: 2025 Frans van Dorsselaer
+//
+// SPDX-License-Identifier: MIT
+
+using System.Diagnostics;
+using System.Security.Cryptography;
+
+namespace Dorssel.Security.Cryptography;
+
+/// <summary>
+/// TODO
+/// </summary>
+public sealed class XmssMemoryStateManager()
+    : IXmssStateManager, IDisposable
+{
+    readonly Dictionary<XmssKeyPart, byte[]?> State = new()
+    {
+        { XmssKeyPart.PrivateStateless, null },
+        { XmssKeyPart.PrivateStateful, null },
+        { XmssKeyPart.Public, null },
+    };
+
+    [StackTraceHidden]
+    void ThrowIfInvalidPart(XmssKeyPart part)
+    {
+        if (!State.ContainsKey(part))
+        {
+            throw new ArgumentOutOfRangeException(nameof(part));
+        }
+    }
+
+    /// <inheritdoc/>
+    public void Store(XmssKeyPart part, ReadOnlySpan<byte> data)
+    {
+        lock (State)
+        {
+            ThrowIfInvalidPart(part);
+
+            ObjectDisposedException.ThrowIf(IsDisposed, this);
+
+            if (State[part] is not null)
+            {
+                throw new InvalidOperationException("Part already exists.");
+            }
+            State[part] = data.ToArray();
+        }
+    }
+
+    /// <inheritdoc/>
+    public void StoreStatefulPart(ReadOnlySpan<byte> expected, ReadOnlySpan<byte> data)
+    {
+        if (data.Length != expected.Length)
+        {
+            throw new ArgumentException("Expected data and new data must have the same size.");
+        }
+
+        lock (State)
+        {
+            ObjectDisposedException.ThrowIf(IsDisposed, this);
+
+            if (State[XmssKeyPart.PrivateStateful] is not byte[] oldData)
+            {
+                throw new InvalidOperationException("Part does not exist.");
+            }
+            if (!expected.SequenceEqual(oldData))
+            {
+                throw new ArgumentException("Expected content mismatch.", nameof(expected));
+            }
+            State[XmssKeyPart.PrivateStateful] = data.ToArray();
+        }
+    }
+
+    /// <inheritdoc/>
+    public void Load(XmssKeyPart part, Span<byte> destination)
+    {
+        lock (State)
+        {
+            ThrowIfInvalidPart(part);
+
+            ObjectDisposedException.ThrowIf(IsDisposed, this);
+
+            if (State[part] is not byte[] data)
+            {
+                throw new InvalidOperationException("Part does not exist.");
+            }
+            if (data.Length != destination.Length)
+            {
+                throw new ArgumentException("Part size mismatch.", nameof(destination));
+            }
+            data.CopyTo(destination);
+        }
+    }
+
+    /// <inheritdoc/>
+    public void DeletePublicPart()
+    {
+        lock (State)
+        {
+            ObjectDisposedException.ThrowIf(IsDisposed, this);
+
+            State[XmssKeyPart.Public] = null;
+        }
+    }
+
+    /// <inheritdoc/>
+    public void DeleteAll()
+    {
+        lock (State)
+        {
+            ObjectDisposedException.ThrowIf(IsDisposed, this);
+
+            CryptographicOperations.ZeroMemory(State[XmssKeyPart.PrivateStateless]);
+            CryptographicOperations.ZeroMemory(State[XmssKeyPart.PrivateStateful]);
+            State[XmssKeyPart.PrivateStateless] = null;
+            State[XmssKeyPart.PrivateStateful] = null;
+            State[XmssKeyPart.Public] = null;
+        }
+    }
+
+    bool IsDisposed;
+
+    /// <inheritdoc/>
+    public void Dispose()
+    {
+        lock (State)
+        {
+            if (!IsDisposed)
+            {
+                DeleteAll();
+                IsDisposed = true;
+            }
+        }
+    }
+}