/// <summary>
/// Gets/Sets the byte at index specified.
/// Index 0 is the most significant byte.
/// </summary>
/// <param name="index">The index to get/set (index 0 is most significant byte)</param>
/// <returns></returns>
public byte this[int index]
{
get
{
// Get bits for index (bits are in LSb, whereas bytes as MSB).
// So byte index 0, is the last 8 bits of the BitArray
BitString bits = this.Substring(BitLength - ((index + 1) * 8), 8);
return(bits.ToBytes().FirstOrDefault());
}
set
{
// Put the single byte in a byte array
byte[] byteArray = new byte[1] {
value
};
// convert that byte array to a bit array
BitArray bits = new BitArray(byteArray);
// For each bit, set that bit in this,
// noting that bits and bytes are in opposite endianness.
for (int i = 0; i < bits.Length; i++)
{
var bitToSet = BitLength - ((index + 1) * 8) + i;
this.Set(bitToSet, bits[i]);
}
}
}
/// <summary>
/// Only for use in SHA3
/// </summary>
/// <returns>Normal hex, but the last byte is truncated to match little endian format</returns>
public string ToLittleEndianHex()
{
if (BitLength == 0)
{
return("00");
}
var bytes = new byte[] { };
// Make a padded BitString if the length isn't % 8
if (BitLength % BITSINBYTE != 0)
{
var padding = BITSINBYTE - BitLength % BITSINBYTE;
var extraBits = BitLength % BITSINBYTE;
var lastBits = this.Substring(0, extraBits);
var paddedBS = new BitString(0);
if (BitLength < BITSINBYTE)
{
paddedBS = BitString.Zeroes(padding);
paddedBS = BitString.ConcatenateBits(paddedBS, lastBits);
}
else
{
var firstBits = this.Substring(extraBits, BitLength - extraBits);
paddedBS = BitString.ConcatenateBits(paddedBS, firstBits);
paddedBS = BitString.ConcatenateBits(paddedBS, BitString.Zeroes(padding));
paddedBS = BitString.ConcatenateBits(paddedBS, lastBits);
}
bytes = paddedBS.ToBytes();
}
else
{
bytes = ToBytes();
}
StringBuilder hex = new StringBuilder(bytes.Length * 2);
for (int index = 0; index < bytes.Length; index++)
{
hex.AppendFormat("{0:x2}", bytes[index]);
}
return(hex.ToString().ToUpper());
}
/// <summary>
/// Shifts bits in the LSB direction. Shift adds 0s to the end.
/// </summary>
/// <remarks>Keeps output length same as input.</remarks>
/// <param name="bStr">THe bitstring to shift</param>
/// <returns></returns>
public static BitString LSBShift(BitString bStr)
{
var block = bStr.ToBytes();
var output = new byte[block.Length];
int i = block.Length;
uint bit = 0;
while (--i >= 0)
{
uint b = block[i];
output[i] = (byte)((b << 1) | bit);
bit = (b >> 7) & 1;
}
return(new BitString(output).GetLeastSignificantBits(bStr.BitLength));
}
public string ToHex()
{
if (BitLength == 0)
{
return("");
}
var bytes = new byte[] { };
// Make a padded BitString if the length isn't % 8
if (BitLength % 8 != 0)
{
var padding = BITSINBYTE - BitLength % BITSINBYTE;
var paddedBS = new BitString(BitLength + padding);
for (var i = 0; i < BitLength; i++)
{
paddedBS.Set(i + padding, Bits[i]);
}
bytes = paddedBS.ToBytes();
}
else
{
bytes = ToBytes();
}
StringBuilder hex = new StringBuilder(bytes.Length * 2);
for (int index = 0; index < bytes.Length; index++)
{
hex.AppendFormat("{0:x2}", bytes[index]);
}
return(hex.ToString().ToUpper());
}
public static BitString ReverseByteOrder(BitString input)
{
return(new BitString(MsbLsbConversionHelpers.ReverseByteOrder(input.ToBytes())));
}
