/// <summary>
/// Converts a provided <see cref="NumeralString"/> to a <see cref="BitString"/>.
///
/// Numerals within the <see cref="NumeralString"/> are int (16 bits) and are converted
/// to bits and concatenated onto a <see cref="BitString"/> then returned.
/// </summary>
/// <param name="numeralString">The <see cref="NumeralString"/> to convert.</param>
/// <returns>The <see cref="BitString"/> representation of a <see cref="NumeralString"/>.</returns>
public static BitString ToBitString(NumeralString numeralString)
{
var bs = new BitString(0);
foreach (var number in numeralString.Numbers)
{
bs = bs.ConcatenateBits(BitString.To32BitString(number).GetLeastSignificantBits(16));
}
return(bs);
}
/// <summary>
/// Takes a BitString and adds LSBs (or MSBs when <see cref="padOntoLsb"/> is false) to make the BitString hit (BitString % modulus = 0)
/// </summary>
/// <param name="bs">The BitString to pad</param>
/// <param name="modulus">The modulus to pad the bitstring such that BitString % modulusToHit = 0</param>
/// <param name="padOntoLsb">When true bits are added on the least significant end, the most significant end otherwise.</param>
/// <returns>The padded BitString</returns>
public static BitString PadToModulus(BitString bs, int modulus, bool padOntoLsb = true)
{
if (bs.BitLength % modulus == 0)
{
return(bs);
}
var bitsToAdd = (modulus - bs.BitLength % modulus);
return(padOntoLsb ?
bs.ConcatenateBits(new BitString(bitsToAdd)) :
new BitString(bitsToAdd).ConcatenateBits(bs));
}
/// <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());
}
public BitString ConcatenateBits(BitString bitsToAppend)
{
return(BitString.ConcatenateBits(this, bitsToAppend));
}