/// <summary>
/// Finalizes SHA-512 hashing
/// </summary>
/// <param name="output">Output buffer</param>
public void Finalize(ArraySegment <byte> output)
{
Preconditions.NotNull(output.Array, nameof(output));
if (output.Count != 64)
{
throw new ArgumentException("Output should be 64 in length");
}
Update(_padding, 0, _padding.Length);
Array16 <ulong> block;
ByteIntegerConverter.Array16LoadBigEndian64(out block, _buffer, 0);
CryptoBytes.InternalWipe(_buffer, 0, _buffer.Length);
int bytesInBuffer = (int)_totalBytes & (BlockSize - 1);
if (bytesInBuffer > BlockSize - 16)
{
Sha512Internal.Core(out _state, ref _state, ref block);
block = default(Array16 <ulong>);
}
block.x15 = (_totalBytes - 1) * 8;
Sha512Internal.Core(out _state, ref _state, ref block);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 0, _state.x0);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 8, _state.x1);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 16, _state.x2);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 24, _state.x3);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 32, _state.x4);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 40, _state.x5);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 48, _state.x6);
ByteIntegerConverter.StoreBigEndian64(output.Array, output.Offset + 56, _state.x7);
_state = default(Array8 <ulong>);
}
/// <summary>
/// Updates internal state with data from the provided array.
/// </summary>
/// <param name="data">Array of bytes</param>
/// <param name="index">Offset of byte sequence</param>
/// <param name="length">Sequence length</param>
public void Update(byte[] data, int index, int length)
{
Array16 <ulong> block;
int bytesInBuffer = (int)_totalBytes & (BlockSize - 1);
_totalBytes += (uint)length;
if (_totalBytes >= ulong.MaxValue / 8)
{
throw new InvalidOperationException("Too much data");
}
// Fill existing buffer
if (bytesInBuffer != 0)
{
var toCopy = Math.Min(BlockSize - bytesInBuffer, length);
Buffer.BlockCopy(data, index, _buffer, bytesInBuffer, toCopy);
index += toCopy;
length -= toCopy;
bytesInBuffer += toCopy;
if (bytesInBuffer == BlockSize)
{
ByteIntegerConverter.Array16LoadBigEndian64(out block, _buffer, 0);
Sha512Internal.Core(out _state, ref _state, ref block);
CryptoBytes.InternalWipe(_buffer, 0, _buffer.Length);
bytesInBuffer = 0;
}
}
// Hash complete blocks without copying
while (length >= BlockSize)
{
ByteIntegerConverter.Array16LoadBigEndian64(out block, data, index);
Sha512Internal.Core(out _state, ref _state, ref block);
index += BlockSize;
length -= BlockSize;
}
// Copy remainder into buffer
if (length > 0)
{
Buffer.BlockCopy(data, index, _buffer, bytesInBuffer, length);
}
}