private static byte[] DecodeDataCore(string encoded)
{
var result = new byte[0];
if (encoded.Length == 0)
{
return(result);
}
BigInteger bn58 = 58;
BigInteger bn = 0;
BigInteger bnChar;
int i = 0;
while (DataEncoder.IsSpace(encoded[i]))
{
i++;
if (i >= encoded.Length)
{
return(result);
}
}
for (int y = i; y < encoded.Length; y++)
{
var p1 = pszBase58.IndexOf(encoded[y]);
if (p1 == -1)
{
while (DataEncoder.IsSpace(encoded[y]))
{
y++;
if (y >= encoded.Length)
{
break;
}
}
if (y != encoded.Length)
{
throw new FormatException("Invalid base 58 string");
}
break;
}
bnChar = new BigInteger(p1);
bn = BigInteger.Multiply(bn, bn58);
bn += bnChar;
}
// Get bignum as little endian data
var vchTmp = bn.ToByteArray();
if (vchTmp.All(b => b == 0))
{
vchTmp = new byte[0];
}
// Trim off sign byte if present
if (vchTmp.Length >= 2 && vchTmp[vchTmp.Length - 1] == 0 && vchTmp[vchTmp.Length - 2] >= 0x80)
{
vchTmp = vchTmp.Take(vchTmp.Length - 1).ToArray();
}
// Restore leading zeros
int nLeadingZeros = 0;
for (int y = i; y < encoded.Length && encoded[y] == pszBase58[0]; y++)
{
nLeadingZeros++;
}
result = new byte[nLeadingZeros + vchTmp.Length];
Array.Copy(vchTmp.Reverse().ToArray(), 0, result, nLeadingZeros, vchTmp.Length);
return(result);
}
