internal static void Subtract(System.Security.Cryptography.BigInt a, System.Security.Cryptography.BigInt b, ref System.Security.Cryptography.BigInt c)
{
byte num = 0;
int num2 = 0;
if (a < b)
{
Subtract(b, a, ref c);
Negate(ref c);
}
else
{
int index = 0;
int size = a.Size;
int num5 = 0;
for (index = 0; index < size; index++)
{
num2 = (a.GetDigit(index) - b.GetDigit(index)) - num;
num = 0;
if (num2 < 0)
{
num2 += 0x100;
num = 1;
}
c.SetDigit(index, (byte)(num2 & 0xff), ref num5);
}
c.Size = num5;
}
}
private static void Multiply(System.Security.Cryptography.BigInt a, int b, ref System.Security.Cryptography.BigInt c)
{
if (b == 0)
{
c.Clear();
}
else
{
int num = 0;
int num2 = 0;
int size = a.Size;
int num4 = 0;
for (int i = 0; i < size; i++)
{
num2 = (b * a.GetDigit(i)) + num;
num = num2 / 0x100;
c.SetDigit(i, (byte)(num2 % 0x100), ref num4);
}
if (num != 0)
{
byte[] bytes = BitConverter.GetBytes(num);
for (int j = 0; j < bytes.Length; j++)
{
c.SetDigit(size + j, bytes[j], ref num4);
}
}
c.Size = num4;
}
}
internal static void Divide(System.Security.Cryptography.BigInt numerator, System.Security.Cryptography.BigInt denominator, ref System.Security.Cryptography.BigInt quotient, ref System.Security.Cryptography.BigInt remainder)
{
if (numerator < denominator)
{
quotient.Clear();
remainder.CopyFrom(numerator);
}
else if (numerator == denominator)
{
quotient.Clear();
quotient.SetDigit(0, 1);
remainder.Clear();
}
else
{
System.Security.Cryptography.BigInt a = new System.Security.Cryptography.BigInt();
a.CopyFrom(numerator);
System.Security.Cryptography.BigInt num2 = new System.Security.Cryptography.BigInt();
num2.CopyFrom(denominator);
uint num3 = 0;
while (num2.Size < a.Size)
{
num2.Multiply(0x100);
num3++;
}
if (num2 > a)
{
num2.Divide(0x100);
num3--;
}
int num4 = 0;
int digit = 0;
int b = 0;
System.Security.Cryptography.BigInt c = new System.Security.Cryptography.BigInt();
quotient.Clear();
for (int i = 0; i <= num3; i++)
{
num4 = (a.Size == num2.Size) ? a.GetDigit(a.Size - 1) : ((0x100 * a.GetDigit(a.Size - 1)) + a.GetDigit(a.Size - 2));
digit = num2.GetDigit(num2.Size - 1);
b = num4 / digit;
if (b >= 0x100)
{
b = 0xff;
}
Multiply(num2, b, ref c);
while (c > a)
{
b--;
Multiply(num2, b, ref c);
}
quotient.Multiply(0x100);
Add(quotient, (byte)b, ref quotient);
Subtract(a, c, ref a);
num2.Divide(0x100);
}
remainder.CopyFrom(a);
}
}
internal void FromDecimal(string decNum)
{
System.Security.Cryptography.BigInt a = new System.Security.Cryptography.BigInt();
System.Security.Cryptography.BigInt c = new System.Security.Cryptography.BigInt();
int length = decNum.Length;
for (int i = 0; i < length; i++)
{
if ((decNum[i] <= '9') && (decNum[i] >= '0'))
{
Multiply(a, 10, ref c);
Add(c, (byte)(decNum[i] - '0'), ref a);
}
}
this.CopyFrom(a);
}
internal static void Negate(ref System.Security.Cryptography.BigInt a)
{
int size = 0;
for (int i = 0; i < 0x80; i++)
{
a.SetDigit(i, (byte)(~a.GetDigit(i) & 0xff), ref size);
}
for (int j = 0; j < 0x80; j++)
{
a.SetDigit(j, (byte)(a.GetDigit(j) + 1), ref size);
if ((a.GetDigit(j) & 0xff) != 0)
{
break;
}
a.SetDigit(j, (byte)(a.GetDigit(j) & 0xff), ref size);
}
a.Size = size;
}
internal static void Add(System.Security.Cryptography.BigInt a, byte b, ref System.Security.Cryptography.BigInt c)
{
byte digit = b;
int num2 = 0;
int size = a.Size;
int num4 = 0;
for (int i = 0; i < size; i++)
{
num2 = a.GetDigit(i) + digit;
c.SetDigit(i, (byte)(num2 & 0xff), ref num4);
digit = (byte)((num2 >> 8) & 0xff);
}
if (digit != 0)
{
c.SetDigit(a.Size, digit, ref num4);
}
c.Size = num4;
}
internal string ToDecimal()
{
if (this.IsZero())
{
return("0");
}
System.Security.Cryptography.BigInt denominator = new System.Security.Cryptography.BigInt(10);
System.Security.Cryptography.BigInt numerator = new System.Security.Cryptography.BigInt();
System.Security.Cryptography.BigInt quotient = new System.Security.Cryptography.BigInt();
System.Security.Cryptography.BigInt remainder = new System.Security.Cryptography.BigInt();
numerator.CopyFrom(this);
char[] array = new char[(int)Math.Ceiling((double)((this.m_size * 2) * 1.21))];
int length = 0;
do
{
Divide(numerator, denominator, ref quotient, ref remainder);
array[length++] = decValues[remainder.IsZero() ? 0 : remainder.m_elements[0]];
numerator.CopyFrom(quotient);
}while (!quotient.IsZero());
Array.Reverse(array, 0, length);
return(new string(array, 0, length));
}
internal void CopyFrom(System.Security.Cryptography.BigInt a)
{
Array.Copy(a.m_elements, this.m_elements, 0x80);
this.m_size = a.m_size;
}
