NCode.CryptoMemory

Provides the ability to manage the lifetime of memory by pinning buffers to prevent duplicate copies in ram and securely zeroing sensitive data when no longer needed.

API

CryptoPool

namespace NCode.CryptoMemory;

/// <summary>
/// Provides a resource pool that enables reusing instances of byte arrays that are
/// pinned during their lifetime and securely zeroed when returned.
/// </summary>
public static class CryptoPool
{
    /// <summary>
    /// Retrieves a buffer that is at least the requested length.
    /// </summary>
    /// <param name="minBufferSize">The minimum length of the buffer needed.</param>
    /// <returns>
    /// An <see cref="IMemoryOwner{T}"/> that manages the lifetime of the lease.
    /// </returns>
    public static IMemoryOwner<byte> Rent(
        int minBufferSize);

    /// <summary>
    /// Retrieves a buffer that is at least the requested length.
    /// </summary>
    /// <param name="minBufferSize">The minimum length of the buffer needed.</param>
    /// <param name="isSensitive">Indicates whether the buffer should be pinned during it's lifetime
    /// and securely zeroed when returned. When <c>false></c>, this implementation delegates to
    /// <c>MemoryPool&lt;byte&gt;.Shared.Rent</c>.</param>
    /// <returns>
    /// An <see cref="IMemoryOwner{T}"/> that manages the lifetime of the lease.
    /// </returns>
    public static IMemoryOwner<byte> Rent(
        int minBufferSize,
        bool isSensitive);

    /// <summary>
    /// Retrieves a buffer that is at least the requested length.
    /// </summary>
    /// <param name="minBufferSize">The minimum length of the buffer needed.</param>
    /// <param name="buffer">When this method returns, contains the buffer with the exact
    /// requested size.</param>
    /// <returns>
    /// An <see cref="IMemoryOwner{T}"/> that manages the lifetime of the lease.
    /// </returns>
    public static IMemoryOwner<byte> Rent(
        int minBufferSize,
        out Span<byte> buffer);

    /// <summary>
    /// Retrieves a buffer that is at least the requested length.
    /// </summary>
    /// <param name="minBufferSize">The minimum length of the buffer needed.</param>
    /// <param name="isSensitive">Indicates whether the buffer should be pinned during it's lifetime
    /// and securely zeroed when returned. When <c>false></c>, this implementation delegates to
    /// <c>MemoryPool&lt;byte&gt;.Shared.Rent</c>.</param>
    /// <param name="buffer">When this method returns, contains the buffer with the exact
    /// requested size.</param>
    /// <returns>
    /// An <see cref="IMemoryOwner{T}"/> that manages the lifetime of the lease.
    /// </returns>
    public static IMemoryOwner<byte> Rent(
        int minBufferSize,
        bool isSensitive,
        out Span<byte> buffer);

    /// <summary>
    /// Retrieves a buffer that is at least the requested length.
    /// </summary>
    /// <param name="minBufferSize">The minimum length of the buffer needed.</param>
    /// <param name="buffer">When this method returns, contains the buffer with the exact
    /// requested size.</param>
    /// <returns>
    /// An <see cref="IMemoryOwner{T}"/> that manages the lifetime of the lease.
    /// </returns>
    public static IMemoryOwner<byte> Rent(
        int minBufferSize,
        out Memory<byte> buffer);

    /// <summary>
    /// Retrieves a buffer that is at least the requested length.
    /// </summary>
    /// <param name="minBufferSize">The minimum length of the buffer needed.</param>
    /// <param name="isSensitive">Indicates whether the buffer should be pinned during it's lifetime
    /// and securely zeroed when returned. When <c>false></c>, this implementation delegates to
    /// <c>MemoryPool&lt;byte&gt;.Shared.Rent</c>.</param>
    /// <param name="buffer">When this method returns, contains the buffer with the exact
    /// requested size.</param>
    /// <returns>
    /// An <see cref="IMemoryOwner{T}"/> that manages the lifetime of the lease.
    /// </returns>
    public static IMemoryOwner<byte> Rent(
        int minBufferSize,
        bool isSensitive,
        out Memory<byte> buffer);
}

HeapMemoryManager

namespace NCode.CryptoMemory;

/// <summary>
/// Provides an implementation of <see cref="MemoryManager{T}"/> that allocates a byte buffer from
/// the heap and securely zeroes the allocated memory when the managed is disposed.
/// </summary>
public class HeapMemoryManager : MemoryManager<byte>
{
    /// <summary>
    /// Initializes a new instance of the <see cref="HeapMemoryManager"/> class.
    /// </summary>
    /// <param name="length">The length in bytes of the allocated memory.</param>
    /// <param name="zeroOnDispose">Specifies whether the allocated memory should be zeroed when
    /// the manager is disposed.</param>
    public HeapMemoryManager(int length, bool zeroOnDispose = true);

    /// <summary>
    /// Gets the memory block handled by this <see cref="MemoryManager{T}"/>.
    /// </summary>
    public Memory<byte> Memory { get; }

    /// <summary>
    /// Returns a memory span that wraps the underlying memory buffer.
    /// </summary>
    public Span<byte> GetSpan();

    /// <summary>
    /// Returns a handle to the memory that has been pinned and whose address can be taken.
    /// </summary>
    /// <param name="elementIndex">The offset to the element in the memory buffer at which the
    /// returned <see cref="MemoryHandle"/> points.</param>
    public MemoryHandle Pin(int elementIndex = 0);

    /// <summary>
    /// Unpins pinned memory so that the garbage collector is free to move it.
    /// </summary>
    /// <remarks>
    /// Since this <see cref="MemoryManager{T}"/> uses memory from the heap which is already
    /// pinned, this implemtation does nothing.
    /// </remarks>
    public void Unpin();
}

Release Notes

• v1.0.0 - Initial release
• v1.0.1 - Updating readme