private static BigInteger[] LucasSequenceHelper(BigInteger P, BigInteger Q, BigInteger k, BigInteger n, BigInteger constant, int s)
{
BigInteger[] result = new BigInteger[3];
if ((k._data[0] & 0x00000001) == 0)
throw (new ArgumentException("Argument k must be odd."));
int numbits = k.BitCount();
uint mask = (uint)0x1 << ((numbits & 0x1F) - 1);
BigInteger v = 2 % n, Q_k = 1 % n,
v1 = P % n, u1 = Q_k;
bool flag = true;
for (int i = k.DataLength - 1; i >= 0; i--)
{
while (mask != 0)
{
if (i == 0 && mask == 0x00000001)
break;
if ((k._data[i] & mask) != 0)
{
u1 = (u1 * v1) % n;
v = ((v * v1) - (P * Q_k)) % n;
v1 = n.BarrettReduction(v1 * v1, n, constant);
v1 = (v1 - ((Q_k * Q) << 1)) % n;
if (flag)
flag = false;
else
Q_k = n.BarrettReduction(Q_k * Q_k, n, constant);
Q_k = (Q_k * Q) % n;
}
else
{
u1 = ((u1 * v) - Q_k) % n;
v1 = ((v * v1) - (P * Q_k)) % n;
v = n.BarrettReduction(v * v, n, constant);
v = (v - (Q_k << 1)) % n;
if (flag)
{
Q_k = Q % n;
flag = false;
}
else
Q_k = n.BarrettReduction(Q_k * Q_k, n, constant);
}
mask >>= 1;
}
mask = 0x80000000;
}
u1 = ((u1 * v) - Q_k) % n;
v = ((v * v1) - (P * Q_k)) % n;
if (flag)
flag = false;
else
Q_k = n.BarrettReduction(Q_k * Q_k, n, constant);
Q_k = (Q_k * Q) % n;
for (int i = 0; i < s; i++)
{
u1 = (u1 * v) % n;
v = ((v * v) - (Q_k << 1)) % n;
if (flag)
{
Q_k = Q % n;
flag = false;
}
else
Q_k = n.BarrettReduction(Q_k * Q_k, n, constant);
}
result[0] = u1;
result[1] = v;
result[2] = Q_k;
return result;
}
/// <summary>
/// Modulo Exponentiation.
/// </summary>
/// <param name="exponent"></param>
/// <param name="modulus"></param>
/// <returns></returns>
public BigInteger ModPow(BigInteger exponent, BigInteger modulus)
{
if ((exponent._data[MAX_LENGTH - 1] & 0x80000000) != 0)
throw (new ArithmeticException("Positive exponents only."));
BigInteger resultNum = 1;
BigInteger tempNum;
bool thisNegative = false;
if ((_data[MAX_LENGTH - 1] & 0x80000000) != 0)
{
tempNum = -this % modulus;
thisNegative = true;
}
else
tempNum = this % modulus;
if ((modulus._data[MAX_LENGTH - 1] & 0x80000000) != 0)
modulus = -modulus;
BigInteger constant = new BigInteger();
int i = modulus.DataLength << 1;
constant._data[i] = 0x00000001;
constant.DataLength = i + 1;
constant = constant / modulus;
int totalBits = exponent.BitCount();
int count = 0;
for (int pos = 0; pos < exponent.DataLength; pos++)
{
uint mask = 0x01;
for (int index = 0; index < 32; index++)
{
if ((exponent._data[pos] & mask) != 0)
resultNum = BarrettReduction(resultNum * tempNum, modulus, constant);
mask <<= 1;
tempNum = BarrettReduction(tempNum * tempNum, modulus, constant);
if (tempNum.DataLength == 1 && tempNum._data[0] == 1)
{
if (thisNegative && (exponent._data[0] & 0x1) != 0)
return -resultNum;
return resultNum;
}
count++;
if (count == totalBits)
break;
}
}
if (thisNegative && (exponent._data[0] & 0x1) != 0) //odd exp
return -resultNum;
return resultNum;
}
public RsaKey(BigInteger e, BigInteger n, BigInteger d, BigInteger p,
BigInteger q, BigInteger dmp1, BigInteger dmq1, BigInteger iqmp)
{
E = e;
N = n;
D = d;
P = p;
Q = q;
Dmp1 = dmp1;
Dmq1 = dmq1;
Iqmp = iqmp;
CanEncrypt = (e != null && n != null);
CanDecrypt = (CanEncrypt && d != null);
BlockSize = (N.BitCount() + 7) / 8;
}