private static string HashValue(ReadOnlySpan <char> value, uint length, Span <byte> bufferSpan)
{
using var hashAlgorithm = SHA256.Create();
Encoding.ASCII.GetBytes(value, bufferSpan);
// Hashed output maxes out at 32 bytes @ 256bit/8 so we're safe to use stackalloc
Span <byte> hash = stackalloc byte[32];
hashAlgorithm.TryComputeHash(bufferSpan, hash, out int _);
// Length maxes out at 64 since we throw if options is greater
return(HexEncoder.Encode(hash.Slice(0, (int)(length / 2))));
}
/// <inheritdoc/>
public string Create(string value, uint length)
{
int len = (int)length;
int byteCount = Encoding.ASCII.GetByteCount(value);
using (var hashAlgorithm = SHA256.Create())
using (IManagedByteBuffer buffer = this.memoryAllocator.AllocateManagedByteBuffer(byteCount))
{
Encoding.ASCII.GetBytes(value, 0, byteCount, buffer.Array, 0);
byte[] hash = hashAlgorithm.ComputeHash(buffer.Array, 0, byteCount);
return($"{HexEncoder.Encode(new Span<byte>(hash).Slice(0, len / 2))}");
}
}