void PrimeSieve::DoSieve()
{
BuildPrimeTable();
const unsigned int maxSieveSize = 32768;
unsigned int sieveSize = STDMIN(Integer(maxSieveSize), (m_last-m_first)/m_step+1).ConvertToLong();
m_sieve.clear();
m_sieve.resize(sieveSize, false);
if (m_delta == 0)
{
for (unsigned int i = 0; i < primeTableSize; ++i)
SieveSingle(m_sieve, primeTable[i], m_first, m_step, m_step.InverseMod(primeTable[i]));
}
else
{
assert(m_step%2==0);
Integer qFirst = (m_first-m_delta) >> 1;
Integer halfStep = m_step >> 1;
for (unsigned int i = 0; i < primeTableSize; ++i)
{
word p = primeTable[i];
word stepInv = m_step.InverseMod(p);
SieveSingle(m_sieve, p, m_first, m_step, stepInv);
word halfStepInv = 2*stepInv < p ? 2*stepInv : 2*stepInv-p;
SieveSingle(m_sieve, p, qFirst, halfStep, halfStepInv);
}
}
}
/*
* function invertRabin : This function invert the Rabin permutation
* param tpPtr : The pointer to the Rabin object
* param element : The element to invert
*/
JNIEXPORT jlong JNICALL Java_edu_biu_scapi_primitives_trapdoorPermutation_cryptopp_CryptoPpRabinPermutation_invertRabin
(JNIEnv *env, jobject, jlong tpPtr, jlong element) {
// Random Number Generator
AutoSeededRandomPool rng;
Utils utils;
//get the Integer value to invert
Integer x = *(Integer*) element;
//invert
((InvertibleRabinFunction *) tpPtr) ->DoQuickSanityCheck();
Integer mod = ((InvertibleRabinFunction *) tpPtr) -> GetModulus();
ModularArithmetic modn(mod);
Integer p = ((InvertibleRabinFunction *) tpPtr)->GetPrime1();
Integer q = ((InvertibleRabinFunction *) tpPtr)->GetPrime2();
Integer cp=x % p;
Integer cq=x % q;
cp = ModularSquareRoot(cp, p);
cq = ModularSquareRoot(cq, q);
Integer v =p.InverseMod(q);
Integer u = ((InvertibleRabinFunction *) tpPtr)->GetMultiplicativeInverseOfPrime2ModPrime1();
Integer onep = modn.Multiply(u,q);
Integer oneq = modn.Multiply(v,p);
Integer outp1 = modn.Multiply(onep,cp);
Integer outp2 = modn.Multiply(onep,p-cp);
Integer outq1 = modn.Multiply(oneq,cq);
Integer outq2 = modn.Multiply(oneq,q-cq);
Integer out = (outp1 + outq1)% mod;
if ((Jacobi(out%p, p) == 1) && (Jacobi(out%q, q) == 1)){
return (jlong) utils.getPointerToInteger(out);
}
out = (outp1 + outq2)%mod;
if ((Jacobi(out%p, p) == 1) && (Jacobi(out%q, q) == 1))
return (jlong) utils.getPointerToInteger(out);
out = (outp2 + outq1)%mod;
if ((Jacobi(out%p, p) == 1) && (Jacobi(out%q, q) == 1))
return (jlong) utils.getPointerToInteger(out);
out = (outp2 + outq2)%mod;
if ((Jacobi(out%p, p) == 1) && (Jacobi(out%q, q) == 1))
return (jlong) utils.getPointerToInteger(out);
//If none of the above cases are true then retun a pointer to the Integer 0.
out = 0;
return (jlong) utils.getPointerToInteger(out);
}
