System.Security.SecureString.Alloc C# (CSharp) Method

		private void Alloc (int length, bool realloc) 
		{
			if ((length < 0) || (length > MaxSize))
				throw new ArgumentOutOfRangeException ("length", "< 0 || > 65536");

			// (size / blocksize) + 1 * blocksize
			// where size = length * 2 (unicode) and blocksize == 16 (ProtectedMemory)
			// length * 2 (unicode) / 16 (blocksize)
			int size = (length >> 3) + (((length & 0x7) == 0) ? 0 : 1) << 4;

			// is re-allocation necessary ? (i.e. grow or shrink 
			// but do not re-allocate the same amount of memory)
			if (realloc && (data != null) && (size == data.Length))
				return;

			if (realloc) {
				// copy, then clear
				byte[] newdata = new byte[size];
				Array.Copy (data, 0, newdata, 0, Math.Min (data.Length, newdata.Length));
				Array.Clear (data, 0, data.Length);
				data = newdata;
			} else {
				data = new byte[size];
			}
		}