/// <summary>
/// Перегрузка оператора инкримента
/// </summary>
public static BigInt32 operator ++(BigInt32 bi1)
{
BigInt32 result = new BigInt32(bi1);
long val, carry = 1;
int index = 0;
while (carry != 0 && index < maxLength)
{
val = (long)(result.data[index]);
val++;
result.data[index] = (uint)(val & 0xFFFFFFFF);
carry = val >> 32;
index++;
}
if (index > result.dataLength)
{
result.dataLength = index;
}
else
{
while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
{
result.dataLength--;
}
}
return(result);
}
/// <summary>
/// Выполняет модульное деление числа, возведенного в степень exp.
/// </summary>
/// <param name="exp">экспонента</param>
/// <param name="n">модуль</param>
/// <returns></returns>
public BigInt32 modPow(BigInt32 exp, BigInt32 n)
{
BigInt32 resultRemainder = 1; // конечный остаток
BigInt32 tempRemainder = this % n; // временный остаток
BigInt32 constant = new BigInt32(); //константа "мю" для алгоритма баррета
int i = n.dataLength << 1;
constant.data[i] = 0x00000001;
constant.dataLength = i + 1;
constant = constant / n;
for (int pos = 0; pos < exp.dataLength; pos++)
{
uint mask = 0x00000001;
for (int index = 0; index < 32; index++)
{
if ((exp.data[pos] & mask) != 0)
{
resultRemainder = AlgorithmOfBarrettReduction(resultRemainder * tempRemainder, n, constant);
}
mask <<= 1;
tempRemainder = AlgorithmOfBarrettReduction(tempRemainder * tempRemainder, n, constant);
}
}
return(resultRemainder);
}
/// <summary>
/// Перегрузка оператора декримента
/// </summary>
public static BigInt32 operator --(BigInt32 bi1)
{
BigInt32 result = new BigInt32(bi1);
long val;
bool carryIn = true;
int index = 0;
while (carryIn && index < maxLength)
{
val = (long)(result.data[index]);
val--;
result.data[index] = (uint)(val & 0xFFFFFFFF);
if (val >= 0)
{
carryIn = false;
}
index++;
}
if (index > result.dataLength)
{
result.dataLength = index;
}
while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
{
result.dataLength--;
}
return(result);
}
/// <summary>
/// Перегрузка оператора сдвига вправо >>
/// </summary>
/// <param name="bi1"></param>
/// <param name="shiftVal"></param>
public static BigInt32 operator >>(BigInt32 bi1, int shiftVal)
{
BigInt32 result = new BigInt32(bi1);
result.dataLength = shiftRight(result.data, shiftVal);
if ((bi1.data[maxLength - 1] & 0x90000000) != 0) // если отрицательное
{
for (int i = maxLength - 1; i >= result.dataLength; i--)
{
result.data[i] = 0xFFFFFFFF;
}
uint mask = 0x90000000;
for (int i = 0; i < 32; i++)
{
if ((result.data[result.dataLength - 1] & mask) != 0)
{
break;
}
result.data[result.dataLength - 1] |= mask;
mask >>= 1;
}
result.dataLength = maxLength;
}
return(result);
}
/// <summary>
/// Вырабатывает ЭЦП сообщения-Text
/// </summary>
/// <param name="Text">Сообщение</param>
/// <returns>Подпись</returns>
public static BigInt32 CreateSignature(byte[] Text, BigInt32 d, BigInt32 n)
{
byte[] hash = MD5hash(Text);
BigInt32 BI_Text = new BigInt32(hash);
return(BI_Text.modPow(d, n));
}
/// <summary>
/// Создание ЭЦП файла
/// </summary>
/// <param name="filename">Имя файла, который мы хотим подписать</param>
static void CreateFilesOfSign(string filename)
{
Encoding enc = Encoding.Default;
byte[] test_byte = File.ReadAllBytes(filename); // байтовое представление исходного файла
FileStream Stream = new FileStream("SecretKey.txt", FileMode.Open, FileAccess.Read);
StreamReader Reader = new StreamReader(Stream);
string D = Reader.ReadLine();
string N = Reader.ReadLine();
Reader.Close();
Stream.Close();
BigInt32 d = new BigInt32(D);
BigInt32 n = new BigInt32(N);
BigInt32 Sign = RSA.CreateSignature(test_byte, d, n); // ЭЦП файла
string FileNameIsSignature = "Sign_" + filename;
Stream = new FileStream(FileNameIsSignature, FileMode.Create, FileAccess.Write);
StreamWriter Writer = new StreamWriter(Stream);
Writer.WriteLine(Sign);
Writer.WriteLine(filename);
Writer.Close();
Stream.Close();
Stream = new FileStream(FileNameIsSignature, FileMode.Append, FileAccess.Write);
BinaryWriter WriterByte = new BinaryWriter(Stream);
WriterByte.Write(test_byte);
WriterByte.Close();
Console.WriteLine("Cоздан файл: {0}", FileNameIsSignature);
}
/// <summary>
/// Расширенный алгоритм Евклида (для нахождения обратного элемента по некоторому модулю)
/// </summary>
private static void Evklid(BigInt32 a, BigInt32 b, ref BigInt32 x, ref BigInt32 y, ref BigInt32 d)
{
BigInt32 q = new BigInt32();
BigInt32 r = new BigInt32();
BigInt32 x1 = new BigInt32();
BigInt32 x2 = new BigInt32();
BigInt32 y1 = new BigInt32();
BigInt32 y2 = new BigInt32();
BigInt32 one = new BigInt32(1);
BigInt32 O = new BigInt32(0);
if (b == O)
{
d = a; x = new BigInt32(1); y = new BigInt32(0);
return;
}
x2 = new BigInt32(1); x1 = new BigInt32(0); y2 = new BigInt32(0); y1 = new BigInt32(1);
while (b > O)
{
q = a / b; r = a % b;
x = x2 - (q * x1); if (q == O || y1 == O)
{
y = y2;
}
else
{
y = y2 - (q * y1);
}
a = b; b = r;
x2 = (x1); x1 = (x); y2 = (y1); y1 = (y);
}
d = (a); x = (x2); y = (y2);
}
/// <summary>
/// Перегрузка оператора сложения
/// </summary>
public static BigInt32 operator +(BigInt32 bi1, BigInt32 bi2)
{
BigInt32 result = new BigInt32();
result.dataLength = (bi1.dataLength > bi2.dataLength) ? bi1.dataLength : bi2.dataLength; //найдет наибольшее
long carry = 0; //перенос
for (int i = 0; i < result.dataLength; i++)
{
long sum = (long)bi1.data[i] + (long)bi2.data[i] + carry;
carry = sum >> 32;
result.data[i] = (uint)(sum & 0xFFFFFFFF);
}
if (carry != 0 && result.dataLength < maxLength)
{
result.data[result.dataLength] = (uint)(carry);
result.dataLength++;
}
while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
{
result.dataLength--;
}
return(result);
}
/// <summary>
/// Перегрузка оператора сдвига влево <<
/// </summary>
/// <param name="bi1"> Папаметр значения </param>
/// <param name="shiftVal"> Величина сдвига</param>
public static BigInt32 operator <<(BigInt32 bi1, int shiftVal)
{
BigInt32 result = new BigInt32(bi1);
result.dataLength = shiftLeft(result.data, shiftVal);
return(result);
}
/// <summary>
/// Возвращает минимальный BigInt32
/// </summary>
public BigInt32 min(BigInt32 bi)
{
if (this < bi)
{
return(new BigInt32(this));
}
else
{
return(new BigInt32(bi));
}
}
/// <summary>
/// Возвращает максимальный BigInt32
/// </summary>
public BigInt32 max(BigInt32 bi)
{
if (this > bi)
{
return(new BigInt32(this));
}
else
{
return(new BigInt32(bi));
}
}
/// <summary>
/// Конструктор копирования
/// </summary>
public BigInt32(BigInt32 bi)
{
data = new uint[maxLength];
dataLength = bi.dataLength;
for (int i = 0; i < dataLength; i++)
{
data[i] = bi.data[i];
}
}
/// <summary>
/// Проверка цифровой подписи файла на подлинность
/// </summary>
/// <param name="filename"> Имя подписанного файла</param>
static void VerificationSignature(string filename)
{
FileStream Stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
StreamReader Reader = new StreamReader(Stream);
string Sign = Reader.ReadLine(); //подпись
string Test_file = Reader.ReadLine(); //имя проверяемого файла
Reader.Close();
Stream.Close();
Stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
BinaryReader ReaderBinary = new BinaryReader(Stream);
FileInfo f = new FileInfo(filename);
int fil = (int)f.Length - (Sign.Length + Test_file.Length);
byte[] s1 = ReaderBinary.ReadBytes(Sign.Length + 2); //
byte[] s2 = ReaderBinary.ReadBytes(Test_file.Length + 2); //
byte[] test_byte = ReaderBinary.ReadBytes(fil); // байтовое представление проверяемых данные
Stream = new FileStream("OpenKey.txt", FileMode.Open, FileAccess.Read);
Reader = new StreamReader(Stream);
string E = Reader.ReadLine();
string N = Reader.ReadLine();
Reader.Close();
Stream.Close();
Encoding enc = Encoding.Default;
BigInt32 Signature = new BigInt32(Sign); //подпись
BigInt32 e = new BigInt32(E); //открытый ключ
BigInt32 n = new BigInt32(N); //модуль
bool finish = false;
finish = RSA.VerifySignature(test_byte, Signature, e, n); // проверка ЭЦП
if (finish)
{
Console.WriteLine("Подпись верна.");
string str_new = "New_" + Test_file;
Stream = new FileStream(str_new, FileMode.Create, FileAccess.Write);
BinaryWriter Writer = new BinaryWriter(Stream);
Writer.Write(test_byte);
Writer.Close();
Stream.Close();
Console.WriteLine("Создан файл: {0}", str_new);
}
else
{
Console.WriteLine("Подпись не верна");
}
}
/// <summary>
/// Проверка цифровой подписи Signature текста Text
/// </summary>
/// <param name="Text">Текст</param>
/// <param name="Signature">Подпись</param>
/// <param name="e">Открытый ключ</param>
/// <param name="n">Модуль</param>
/// <returns>true если подпись верна, false в обратном случае</returns>
public static bool VerifySignature(byte[] Text, BigInt32 Signature, BigInt32 e, BigInt32 n)
{
BigInt32 R = new BigInt32(MD5hash(Text));
//Console.WriteLine(R);
BigInt32 S = new BigInt32(Signature.modPow(e, n));
//Console.WriteLine(S);
if (R == S)
{
return(true);
}
return(false);
}
/// <summary>
/// Алгоритм Евклида
/// </summary>
/// <returns> НОД </returns>
public BigInt32 gcd(BigInt32 bi)
{
BigInt32 x = this;
BigInt32 y = bi;
BigInt32 g = x;
while (x.dataLength > 1 || (x.dataLength == 1 && x.data[0] != 0))
{
g = x;
x = y % x;
y = g;
}
return(g);
}
//***************************************************************************************
//***************************************************************************************
/// <summary>
/// Генерирует положительный BigInt32. С большой вероятностью простое.+
/// </summary>
public static BigInt32 GetPseudoPrime(int bits, int confidence, Random rand)
{
BigInt32 result = new BigInt32();
bool done = false;
while (!done)
{
result.GetRandomBits(bits, rand);
result.data[0] = 0x01; // делает сгенерированное число нечетным
done = result.RabinMillerTest(confidence); //проверяем на простоту
}
return(result);
}
/// <summary>
/// Статический НОД чисел а и в
/// </summary>
public static BigInt32 NOD(BigInt32 a, BigInt32 b)
{
while (a != 0 && b != 0)
{
if (a >= b)
{
a = a % b;
}
else
{
b = b % a;
}
}
return(a + b);
}
/// <summary>
/// Определяет считаются ли равными объекты класса BigInt32
/// </summary>
public override bool Equals(object o)
{
BigInt32 bi = (BigInt32)o;
if (this.dataLength != bi.dataLength)
{
return(false);
}
for (int i = 0; i < this.dataLength; i++)
{
if (this.data[i] != bi.data[i])
{
return(false);
}
}
return(true);
}
/// <summary>
/// Возвращает строку из BigInt32
/// </summary>
public override string ToString()
{
string result = "";
BigInt32 a = this;
BigInt32 quotient = new BigInt32();
BigInt32 remainder = new BigInt32();
while (a.dataLength > 1 || (a.dataLength == 1 && a.data[0] != 0))
{
AlgorithmOfDivideSingleByte(a, 10, quotient, remainder);
result = remainder.data[0] + result;
a = quotient;
}
return(result);
}
/// <summary>
/// Перегрузка оператора вычитания
/// </summary>
public static BigInt32 operator -(BigInt32 bi1, BigInt32 bi2)
{
BigInt32 result = new BigInt32();
result.dataLength = (bi1.dataLength > bi2.dataLength) ? bi1.dataLength : bi2.dataLength; // ищет наибольший
long carryIn = 0;
for (int i = 0; i < result.dataLength; i++)
{
long diff;
diff = (long)bi1.data[i] - (long)bi2.data[i] - carryIn;
result.data[i] = (uint)(diff & 0xFFFFFFFF);
if (diff < 0)
{
carryIn = 1;
}
else
{
carryIn = 0;
}
}
// взять обратный
if (carryIn != 0)
{
for (int i = result.dataLength; i < maxLength; i++)
{
result.data[i] = 0xFFFFFFFF;
}
result.dataLength = maxLength;
}
while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
{
result.dataLength--;
}
return(result);
}
/// <summary>
/// Представляет длинное число из строки
/// </summary>
/// <param name="value">Исходная строка</param>
/// <param name="radix">Основание</param>
public BigInt32(string value)
{
BigInt32 multiplier = new BigInt32(1);
BigInt32 result = new BigInt32();
for (int i = value.Length - 1; i >= 0; i--)
{
int posVal = value[i];
if (posVal >= '0' && posVal <= '9')
{
posVal -= '0';
}
else
{
posVal = 9999999;
}
if (value[0] == '-')
{
posVal = -posVal;
}
result = result + (multiplier * posVal);
if ((i - 1) >= 0)
{
multiplier = multiplier * 10;
}
}
data = new uint[maxLength];
for (int i = 0; i < result.dataLength; i++)
{
data[i] = result.data[i];
}
dataLength = result.dataLength;
}
/// <summary>
/// Ищет обратный элемент к e по модулю n
/// </summary>
public static BigInt32 Inverse(BigInt32 е, BigInt32 n)
{
BigInt32 O = new BigInt32(0);
BigInt32 ONE = new BigInt32(1);
BigInt32 d = new BigInt32(0);
BigInt32 x = new BigInt32(0);
BigInt32 y = new BigInt32(0);
Evklid(е, n, ref x, ref y, ref d);
if (d == ONE)
{
if (x < O)
{
return(x + n);
}
else
{
return(x);
}
}
return(O);
}
/// <summary>
/// Перегрузка оператора присваивания остатка
/// </summary>
public static BigInt32 operator %(BigInt32 bi1, BigInt32 bi2)
{
BigInt32 quotient = new BigInt32();
BigInt32 remainder = new BigInt32(bi1);
if (bi1 < bi2)
{
return(remainder);
}
else
{
if (bi2.dataLength == 1)
{
AlgorithmOfDivideSingleByte(bi1, bi2, quotient, remainder);
}
else
{
AlgorithmOfDivideMultiByte(bi1, bi2, quotient, remainder);
}
return(remainder);
}
}
/// <summary>
/// Перегрузка оператора деления
/// </summary>
public static BigInt32 operator /(BigInt32 bi1, BigInt32 bi2)
{
BigInt32 quotient = new BigInt32(); //частное
BigInt32 remainder = new BigInt32(); //остаток
if (bi1 < bi2)
{
return(quotient); //0
}
else
{
if (bi2.dataLength == 1)
{
AlgorithmOfDivideSingleByte(bi1, bi2, quotient, remainder);
}
else
{
AlgorithmOfDivideMultiByte(bi1, bi2, quotient, remainder);
}
return(quotient);
}
}
/// <summary>
/// Конструктор. Генерирует и проверяет ключи.
/// </summary>
public RSA()
{
Random uy = new Random();
const int KeyOFLenght = 128; // Длина p и q
BigInt32 p = BigInt32.GetPseudoPrime(KeyOFLenght, 10, uy);
BigInt32 q = BigInt32.GetPseudoPrime(KeyOFLenght - 1, 10, uy);
//Console.WriteLine("q = {0}, p = {1}", q, p);
n = p * q;
//Console.WriteLine("n= {0}", n);
p--;
q--;
BigInt32 w = p * q; // функция Эйлера
e = new BigInt32(); // открытый ключ
do
{
e.GetRandomBits(KeyOFLenght * 2, uy);
}while (BigInt32.NOD(e, w) != 1 && (e > n));
d = BigInt32.Inverse(e, w); // d - закрытый ключ (обратный к е по модулю w)
} // d - существует <=> НОД(e,w) = 1
/// <summary>
/// Перегрузка оператора отрицания
/// </summary>
public static BigInt32 operator -(BigInt32 bi1)
{
if (bi1.dataLength == 1 && bi1.data[0] == 0)
{
return(new BigInt32(1));
}
BigInt32 result = new BigInt32(bi1);
for (int i = 0; i < maxLength; i++)
{
result.data[i] = (uint)(~(bi1.data[i]));
}
long val, carry = 1;
int index = 0;
while (carry != 0 && index < maxLength)
{
val = (long)(result.data[index]);
val++;
result.data[index] = (uint)(val & 0xFFFFFFFF);
carry = val >> 32;
index++;
}
result.dataLength = maxLength;
while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
{
result.dataLength--;
}
return(result);
}
/// <summary>
/// Создает файлы "OpenKey.txt" с открытым ключом и "Secret.txt" c закрытым
/// </summary>
static void CreateFilesOfKeys()
{
RSA rsa = new RSA();
BigInt32 E = new BigInt32(rsa.e);
BigInt32 D = new BigInt32(rsa.d);
BigInt32 N = new BigInt32(rsa.n);
FileStream Stream = new FileStream("OpenKey.txt", FileMode.Create, FileAccess.Write);
StreamWriter Writer = new StreamWriter(Stream);
Writer.WriteLine(E);
Writer.WriteLine(N);
Writer.Close();
Stream.Close();
Stream = new FileStream("SecretKey.txt", FileMode.Create, FileAccess.Write);
Writer = new StreamWriter(Stream);
Writer.WriteLine(D);
Writer.WriteLine(N);
Writer.Close();
Stream.Close();
Console.WriteLine("Файлы созданы.");
}
/// <summary>
/// Алгоритм деления числа BigInt32 на однозначное число
/// </summary>
private static void AlgorithmOfDivideSingleByte(BigInt32 bi1, BigInt32 bi2, BigInt32 Quotient, BigInt32 Remainder)
{
uint[] result = new uint[maxLength];
int resultPos = 0;
// Копируем ....
for (int i = 0; i < maxLength; i++)
{
Remainder.data[i] = bi1.data[i];
}
Remainder.dataLength = bi1.dataLength;
while (Remainder.dataLength > 1 && Remainder.data[Remainder.dataLength - 1] == 0)
{
Remainder.dataLength--;
}
ulong divisor = (ulong)bi2.data[0];
int pos = Remainder.dataLength - 1;
ulong dividend = (ulong)Remainder.data[pos];
if (dividend >= divisor)
{
ulong quotient = dividend / divisor;
result[resultPos++] = (uint)quotient;
Remainder.data[pos] = (uint)(dividend % divisor);
}
pos--;
while (pos >= 0)
{
dividend = ((ulong)Remainder.data[pos + 1] << 32) + (ulong)Remainder.data[pos];
ulong quotient = dividend / divisor;
result[resultPos++] = (uint)quotient;
Remainder.data[pos + 1] = 0;
Remainder.data[pos--] = (uint)(dividend % divisor);
}
Quotient.dataLength = resultPos;
int j = 0;
for (int i = Quotient.dataLength - 1; i >= 0; i--, j++)
{
Quotient.data[j] = result[i];
}
for (; j < maxLength; j++)
{
Quotient.data[j] = 0;
}
while (Quotient.dataLength > 1 && Quotient.data[Quotient.dataLength - 1] == 0)
{
Quotient.dataLength--;
}
if (Quotient.dataLength == 0)
{
Quotient.dataLength = 1;
}
while (Remainder.dataLength > 1 && Remainder.data[Remainder.dataLength - 1] == 0)
{
Remainder.dataLength--;
}
}
/// <summary>
/// Алгоритм деления двух больших чисел.
/// Делитель содержит больше 1 цифры
/// </summary>
/// <param name="bi1">Делимое</param>
/// <param name="bi2">Делитель</param>
/// <param name="Quotient">Частное</param>
/// <param name="Remainder">Остаток</param>
private static void AlgorithmOfDivideMultiByte(BigInt32 bi1, BigInt32 bi2, BigInt32 Quotient, BigInt32 Remainder)
{
uint[] result = new uint[maxLength];
int remainderLen = bi1.dataLength + 1;
uint[] remainder = new uint[remainderLen];
uint mask = 0x90000000; //битовая маска
uint val = bi2.data[bi2.dataLength - 1];
int shift = 0, resultPos = 0;
while (mask != 0 && (val & mask) == 0)
{
shift++; mask >>= 1;
}
for (int i = 0; i < bi1.dataLength; i++)
{
remainder[i] = bi1.data[i];
}
shiftLeft(remainder, shift);
bi2 = bi2 << shift;
int j = remainderLen - bi2.dataLength;
int pos = remainderLen - 1;
ulong firstDivisorByte = bi2.data[bi2.dataLength - 1];
ulong secondDivisorByte = bi2.data[bi2.dataLength - 2];
int divisorLen = bi2.dataLength + 1;
uint[] dividendPart = new uint[divisorLen];
while (j > 0)
{
ulong dividend = ((ulong)remainder[pos] << 32) + (ulong)remainder[pos - 1];
ulong q_hat = dividend / firstDivisorByte;
ulong r_hat = dividend % firstDivisorByte;
bool done = false;
while (!done)
{
done = true;
if (q_hat == 0x100000000 ||
(q_hat * secondDivisorByte) > ((r_hat << 32) + remainder[pos - 2]))
{
q_hat--;
r_hat += firstDivisorByte;
if (r_hat < 0x100000000)
{
done = false;
}
}
}
for (int h = 0; h < divisorLen; h++)
{
dividendPart[h] = remainder[pos - h];
}
BigInt32 kk = new BigInt32(dividendPart);
BigInt32 ss = bi2 * (long)q_hat;
while (ss > kk)
{
q_hat--;
ss -= bi2;
}
BigInt32 yy = kk - ss;
for (int h = 0; h < divisorLen; h++)
{
remainder[pos - h] = yy.data[bi2.dataLength - h];
}
result[resultPos++] = (uint)q_hat;
pos--;
j--;
}
Quotient.dataLength = resultPos;
int y = 0;
for (int x = Quotient.dataLength - 1; x >= 0; x--, y++)
{
Quotient.data[y] = result[x];
}
for (; y < maxLength; y++)
{
Quotient.data[y] = 0;
}
while (Quotient.dataLength > 1 && Quotient.data[Quotient.dataLength - 1] == 0)
{
Quotient.dataLength--;
}
if (Quotient.dataLength == 0)
{
Quotient.dataLength = 1;
}
Remainder.dataLength = shiftRight(remainder, shift);
for (y = 0; y < Remainder.dataLength; y++)
{
Remainder.data[y] = remainder[y];
}
for (; y < maxLength; y++)
{
Remainder.data[y] = 0;
}
}
/// <summary>
/// Перегрузка оператора умножения
/// </summary>
public static BigInt32 operator *(BigInt32 bi1, BigInt32 bi2)
{
int lastPos = maxLength - 1;
bool bi1Neg = false, bi2Neg = false;
// берем bi1 и bi2 по модулю
if ((bi1.data[lastPos] & 0x90000000) != 0) // bi1 отрицательный
{
bi1Neg = true; bi1 = -bi1;
}
if ((bi2.data[lastPos] & 0x90000000) != 0) // bi2 отрицательный
{
bi2Neg = true; bi2 = -bi2;
}
BigInt32 result = new BigInt32();
// Умножение абсолютных велечин
for (int i = 0; i < bi1.dataLength; i++)
{
if (bi1.data[i] == 0)
{
continue;
}
ulong mcarry = 0;
for (int j = 0, k = i; j < bi2.dataLength; j++, k++)
{
// k = i + j
ulong val = ((ulong)bi1.data[i] * (ulong)bi2.data[j]) +
(ulong)result.data[k] + mcarry;
result.data[k] = (uint)(val & 0xFFFFFFFF);
mcarry = (val >> 32);
}
if (mcarry != 0)
{
result.data[i + bi2.dataLength] = (uint)mcarry;
}
}
result.dataLength = bi1.dataLength + bi2.dataLength;
if (result.dataLength > maxLength)
{
result.dataLength = maxLength;
}
while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
{
result.dataLength--;
}
// проверка переполнения
if ((result.data[lastPos] & 0x90000000) != 0)
{
if (bi1Neg != bi2Neg && result.data[lastPos] == 0x90000000) // bi1 и bi2 разного знака
{
//обрабатывать особый случай, когда умножение производит
// максимальное отрицательное число в 2сс
if (result.dataLength == 1)
{
return(result);
}
else
{
bool isMaxNeg = true;
for (int i = 0; i < result.dataLength - 1 && isMaxNeg; i++)
{
if (result.data[i] != 0)
{
isMaxNeg = false;
}
}
if (isMaxNeg)
{
return(result);
}
}
}
}
// Если знаки разные
if (bi1Neg != bi2Neg)
{
return(-result);
}
return(result);
}
