HashProviderCng.cs

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using System;
using Microsoft.Win32.SafeHandles;
 
namespace Internal.Cryptography;
 
internal sealed class HashProviderCng : Internal.Cryptography.HashProvider
{
    private readonly Microsoft.Win32.SafeHandles.SafeBCryptAlgorithmHandle _hAlgorithm;
 
    private Microsoft.Win32.SafeHandles.SafeBCryptHashHandle _hHash;
 
    private byte[] _key;
 
    private readonly bool _reusable;
 
    private readonly int _hashSize;
 
    private bool _running;
 
    public sealed override int HashSizeInBytes => _hashSize;
 
    public HashProviderCng(string hashAlgId, byte[] key)
        : this(hashAlgId, key, key != null)
    {
    }
    public HashProviderCng(string hashAlgId, byte[] key) {…}
 
    internal HashProviderCng(string hashAlgId, ReadOnlySpan<byte> key, bool isHmac)
    {
        global::Interop.BCrypt.BCryptOpenAlgorithmProviderFlags bCryptOpenAlgorithmProviderFlags = global::Interop.BCrypt.BCryptOpenAlgorithmProviderFlags.None;
        if (isHmac)
        {
            _key = key.ToArray();
            bCryptOpenAlgorithmProviderFlags |= global::Interop.BCrypt.BCryptOpenAlgorithmProviderFlags.BCRYPT_ALG_HANDLE_HMAC_FLAG;
        }
        _hAlgorithm = global::Interop.BCrypt.BCryptAlgorithmCache.GetCachedBCryptAlgorithmHandle(hashAlgId, bCryptOpenAlgorithmProviderFlags, out _hashSize);
        Microsoft.Win32.SafeHandles.SafeBCryptHashHandle phHash;
        global::Interop.BCrypt.NTSTATUS nTSTATUS = global::Interop.BCrypt.BCryptCreateHash(_hAlgorithm, out phHash, IntPtr.Zero, 0, key, (!(key == null)) ? key.Length : 0, global::Interop.BCrypt.BCryptCreateHashFlags.BCRYPT_HASH_REUSABLE_FLAG);
        switch (nTSTATUS)
        {
        case global::Interop.BCrypt.NTSTATUS.STATUS_INVALID_PARAMETER:
            phHash.Dispose();
            Reset();
            break;
        default:
            phHash.Dispose();
            throw global::Interop.BCrypt.CreateCryptographicException(nTSTATUS);
        case global::Interop.BCrypt.NTSTATUS.STATUS_SUCCESS:
            _hHash = phHash;
            _reusable = true;
            break;
        }
    }
    internal HashProviderCng(string hashAlgId, ReadOnlySpan<byte> key, bool isHmac) {…}
 
    public sealed override void AppendHashData(ReadOnlySpan<byte> source)
    {
        global::Interop.BCrypt.NTSTATUS nTSTATUS = global::Interop.BCrypt.BCryptHashData(_hHash, source, source.Length, 0);
        if (nTSTATUS != 0)
        {
            throw global::Interop.BCrypt.CreateCryptographicException(nTSTATUS);
        }
        _running = true;
    }
    public sealed override void AppendHashData(ReadOnlySpan<byte> source) {…}
 
    public override int FinalizeHashAndReset(Span<byte> destination)
    {
        global::Interop.BCrypt.NTSTATUS nTSTATUS = global::Interop.BCrypt.BCryptFinishHash(_hHash, destination, _hashSize, 0);
        if (nTSTATUS != 0)
        {
            throw global::Interop.BCrypt.CreateCryptographicException(nTSTATUS);
        }
        _running = false;
        Reset();
        return _hashSize;
    }
    public override int FinalizeHashAndReset(Span<byte> destination) {…}
 
    public sealed override void Dispose(bool disposing)
    {
        if (disposing)
        {
            DestroyHash();
            if (_key != null)
            {
                byte[] key = _key;
                _key = null;
                Array.Clear(key);
            }
        }
    }
    public sealed override void Dispose(bool disposing) {…}
 
    public override void Reset()
    {
        if (!_reusable || _running)
        {
            DestroyHash();
            Microsoft.Win32.SafeHandles.SafeBCryptHashHandle phHash;
            global::Interop.BCrypt.NTSTATUS nTSTATUS = global::Interop.BCrypt.BCryptCreateHash(_hAlgorithm, out phHash, IntPtr.Zero, 0, _key, (_key != null) ? _key.Length : 0, global::Interop.BCrypt.BCryptCreateHashFlags.None);
            if (nTSTATUS != 0)
            {
                throw global::Interop.BCrypt.CreateCryptographicException(nTSTATUS);
            }
            _hHash = phHash;
        }
    }
    public override void Reset() {…}
 
    private void DestroyHash()
    {
        Microsoft.Win32.SafeHandles.SafeBCryptHashHandle hHash = _hHash;
        _hHash = null;
        hHash?.Dispose();
    }
    private void DestroyHash() {…}
}