biginteger.cs

Algorithm Festel. Programs read from file to array byte[]. key block = 64 data block = 128 if use

                count -= shiftAmount;
            }

            while (bufLen > 1 && buffer[bufLen - 1] == 0)
                bufLen--;

            return bufLen;
        }


        //***********************************************************************
        // Overloading of the NOT operator (1's complement)
        //***********************************************************************

        public static BigInteger operator ~(BigInteger bi1)
        {
            BigInteger result = new BigInteger(bi1);

            for (int i = 0; i < maxLength; i++)
                result.data[i] = (uint)(~(bi1.data[i]));

            result.dataLength = maxLength;

            while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
                result.dataLength--;

            return result;
        }


        //***********************************************************************
        // Overloading of the NEGATE operator (2's complement)
        //***********************************************************************

        public static BigInteger operator -(BigInteger bi1)
        {
            // handle neg of zero separately since it'll cause an overflow
            // if we proceed.

            if (bi1.dataLength == 1 && bi1.data[0] == 0)
                return (new BigInteger());

            BigInteger result = new BigInteger(bi1);

            // 1's complement
            for (int i = 0; i < maxLength; i++)
                result.data[i] = (uint)(~(bi1.data[i]));

            // add one to result of 1's complement
            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 ((bi1.data[maxLength - 1] & 0x80000000) == (result.data[maxLength - 1] & 0x80000000))
                throw (new ArithmeticException("Overflow in negation.\n"));

            result.dataLength = maxLength;

            while (result.dataLength > 1 && result.data[result.dataLength - 1] == 0)
                result.dataLength--;
            return result;
        }


        //***********************************************************************
        // Overloading of equality operator
        //***********************************************************************

        public static bool operator ==(BigInteger bi1, BigInteger bi2)
        {
            return bi1.Equals(bi2);
        }


        public static bool operator !=(BigInteger bi1, BigInteger bi2)
        {
            return !(bi1.Equals(bi2));
        }


        public override bool Equals(object o)
        {
            BigInteger bi = (BigInteger)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;
        }


        public override int GetHashCode()
        {
            return this.ToString().GetHashCode();
        }


        //***********************************************************************
        // Overloading of inequality operator
        //***********************************************************************

        public static bool operator >(BigInteger bi1, BigInteger bi2)
        {
            int pos = maxLength - 1;

            // bi1 is negative, bi2 is positive
            if ((bi1.data[pos] & 0x80000000) != 0 && (bi2.data[pos] & 0x80000000) == 0)
                return false;

                // bi1 is positive, bi2 is negative
            else if ((bi1.data[pos] & 0x80000000) == 0 && (bi2.data[pos] & 0x80000000) != 0)
                return true;

            // same sign
            int len = (bi1.dataLength > bi2.dataLength) ? bi1.dataLength : bi2.dataLength;
            for (pos = len - 1; pos >= 0 && bi1.data[pos] == bi2.data[pos]; pos--) ;

            if (pos >= 0)
            {
                if (bi1.data[pos] > bi2.data[pos])
                    return true;
                return false;
            }
            return false;
        }


        public static bool operator <(BigInteger bi1, BigInteger bi2)
        {
            int pos = maxLength - 1;

            // bi1 is negative, bi2 is positive
            if ((bi1.data[pos] & 0x80000000) != 0 && (bi2.data[pos] & 0x80000000) == 0)
                return true;

                // bi1 is positive, bi2 is negative
            else if ((bi1.data[pos] & 0x80000000) == 0 && (bi2.data[pos] & 0x80000000) != 0)
                return false;

            // same sign
            int len = (bi1.dataLength > bi2.dataLength) ? bi1.dataLength : bi2.dataLength;
            for (pos = len - 1; pos >= 0 && bi1.data[pos] == bi2.data[pos]; pos--) ;

            if (pos >= 0)
            {
                if (bi1.data[pos] < bi2.data[pos])
                    return true;
                return false;
            }
            return false;
        }


        public static bool operator >=(BigInteger bi1, BigInteger bi2)
        {
            return (bi1 == bi2 || bi1 > bi2);
        }


        public static bool operator <=(BigInteger bi1, BigInteger bi2)
        {
            return (bi1 == bi2 || bi1 < bi2);
        }


        //***********************************************************************
        // Private function that supports the division of two numbers with
        // a divisor that has more than 1 digit.
        //
        // Algorithm taken from [1]
        //***********************************************************************

        private static void multiByteDivide(BigInteger bi1, BigInteger bi2,
                                            BigInteger outQuotient, BigInteger outRemainder)
        {
            uint[] result = new uint[maxLength];

            int remainderLen = bi1.dataLength + 1;
            uint[] remainder = new uint[remainderLen];

            uint mask = 0x80000000;
            uint val = bi2.data[bi2.dataLength - 1];
            int shift = 0, resultPos = 0;

            while (mask != 0 && (val & mask) == 0)
            {
                shift++; mask >>= 1;
            }

            //Console.WriteLine("shift = {0}", shift);
            //Console.WriteLine("Before bi1 Len = {0}, bi2 Len = {1}", bi1.dataLength, bi2.dataLength);

            for (int i = 0; i < bi1.dataLength; i++)
                remainder[i] = bi1.data[i];
            shiftLeft(remainder, shift);
            bi2 = bi2 << shift;

            /*
            Console.WriteLine("bi1 Len = {0}, bi2 Len = {1}", bi1.dataLength, bi2.dataLength);
            Console.WriteLine("dividend = " + bi1 + "\ndivisor = " + bi2);
            for(int q = remainderLen - 1; q >= 0; q--)
                    Console.Write("{0:x2}", remainder[q]);
            Console.WriteLine();
            */

            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];
                //Console.WriteLine("dividend = {0}", dividend);

                ulong q_hat = dividend / firstDivisorByte;
                ulong r_hat = dividend % firstDivisorByte;

                //Console.WriteLine("q_hat = {0:X}, r_hat = {1:X}", q_hat, r_hat);

                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];

                BigInteger kk = new BigInteger(dividendPart);
                BigInteger ss = bi2 * (long)q_hat;

                //Console.WriteLine("ss before = " + ss);
                while (ss > kk)
                {
                    q_hat--;
                    ss -= bi2;
                    //Console.WriteLine(ss);
                }
                BigInteger yy = kk - ss;

                //Console.WriteLine("ss = " + ss);
                //Console.WriteLine("kk = " + kk);
                //Console.WriteLine("yy = " + yy);

                for (int h = 0; h < divisorLen; h++)
                    remainder[pos - h] = yy.data[bi2.dataLength - h];

                /*
                Console.WriteLine("dividend = ");
                for(int q = remainderLen - 1; q >= 0; q--)
                        Console.Write("{0:x2}", remainder[q]);
                Console.WriteLine("\n************ q_hat = {0:X}\n", q_hat);
                */

                result[resultPos++] = (uint)q_hat;

                pos--;
                j--;
            }

            outQuotient.dataLength = resultPos;
            int y = 0;
            for (int x = outQuotient.dataLength - 1; x >= 0; x--, y++)
                outQuotient.data[y] = result[x];
            for (; y < maxLength; y++)
                outQuotient.data[y] = 0;

            while (outQuotient.dataLength > 1 && outQuotient.data[outQuotient.dataLength - 1] == 0)
                outQuotient.dataLength--;

            if (outQuotient.dataLength == 0)
                outQuotient.dataLength = 1;

            outRemainder.dataLength = shiftRight(remainder, shift);

            for (y = 0; y < outRemainder.dataLength; y++)
                outRemainder.data[y] = remainder[y];
            for (; y < maxLength; y++)
                outRemainder.data[y] = 0;
        }


        //***********************************************************************
        // Private function that supports the division of two numbers with
        // a divisor that has only 1 digit.
        //***********************************************************************

        private static void singleByteDivide(BigInteger bi1, BigInteger bi2,
                                             BigInteger outQuotient, BigInteger outRemainder)
        {
            uint[] result = new uint[maxLength];
            int resultPos = 0;

            // copy dividend to reminder
            for (int i = 0; i < maxLength; i++)
                outRemainder.data[i] = bi1.data[i];
            outRemainder.dataLength = bi1.dataLength;

            while (outRemainder.dataLength > 1 && outRemainder.data[outRemainder.dataLength - 1] == 0)
                outRemainder.dataLength--;

            ulong divisor = (ulong)bi2.data[0];
            int pos = outRemainder.dataLength - 1;
            ulong dividend = (ulong)outRemainder.data[pos];

            //Console.WriteLine("divisor = " + divisor + " dividend = " + dividend);
            //Console.WriteLine("divisor = " + bi2 + "\ndividend = " + bi1);

            if (dividend >= divisor)
            {
                ulong quotient = dividend / divisor;
                result[resultPos++] = (uint)quotient;

                outRemainder.data[pos] = (uint)(dividend % divisor);
            }
            pos--;

            while (pos >= 0)
            {
                //Console.WriteLine(pos);

                dividend = ((ulong)outRemainder.data[pos + 1] << 32) + (ulong)outRemainder.data[pos];
                ulong quotient = dividend / divisor;
                result[resultPos++] = (uint)quotient;

                outRemainder.data[pos + 1] = 0;
                outRemainder.data[pos--] = (uint)(dividend % divisor);
                //Console.WriteLine(">>>> " + bi1);
            }

            outQuotient.dataLength = resultPos;
            int j = 0;
            for (int i = outQuotient.dataLength - 1; i >= 0; i--, j++)
                outQuotient.data[j] = result[i];
            for (; j < maxLength; j++)
                outQuotient.data[j] = 0;

            while (outQuotient.dataLength > 1 && outQuotient.data[outQuotient.dataLength - 1] == 0)
                outQuotient.dataLength--;

            if (outQuotient.dataLength == 0)
                outQuotient.dataLength = 1;

            while (outRemainder.dataLength > 1 && outRemainder.data[outRemainder.dataLength - 1] == 0)
                outRemainder.dataLength--;
        }