private static byte[] ConvertFromKey(string key, byte base2)
{
if (Base32Decoder.IsEmpty(key))
{
return((byte[])null);
}
uint num1 = (uint)Math.Floor((double)base2 / 8.0 * (double)key.Length);
byte[] numArray = new byte[(int)num1];
if (Base32Decoder.IsEmpty((Array)numArray))
{
return((byte[])null);
}
for (int index = 0; index < numArray.Length; ++index)
{
numArray[index] = (byte)0;
}
int num2 = 0;
int num3 = key.Length - 1;
byte num4 = 0;
while (num3 >= 0 && (long)num2 < (long)(num1 * 8U))
{
byte val = Base32Decoder.CharToVal(key[num3--]);
int num5 = (int)numArray[num2 / 8] + ((int)val << num2 % 8) + (int)num4;
num4 = (byte)(num5 / 256);
numArray[num2 / 8] = (byte)(num5 % 256);
num2 += (int)base2;
}
return(numArray);
}
private static byte CharToVal(char c)
{
c = char.ToLower(c);
if (48 > (int)c || (int)c > 57)
{
return((byte)Base32Decoder.TrimNegative((int)(byte)((int)c - 97 + 10)));
}
return((byte)Base32Decoder.TrimNegative((int)(byte)((uint)c - 48U)));
}
public static byte[] Decode(string str)
{
return(Base32Decoder.ConvertFromKey(str, (byte)5));
}