bool RSA::isPrime(const ZZ& prime, long t)
{
if (prime <= 1)
return false;
// First, just try out the division by the first 2000 primes
// Source: http://www.shoup.net/ntl/doc/tour-ex1.html
PrimeSeq primeSequence;
long tempPrime;
tempPrime = primeSequence.next();
while(tempPrime && tempPrime < 2000)
{
if((prime % tempPrime) == 0)
return prime == tempPrime;
tempPrime = primeSequence.next();
}
// Not it's time for real prime testing
ZZ x;
long i;
for(i = 0; i < t; i++)
{
x = bigRandom(this->numberOfBits / 4); // random number between 0 and n-1
if (MRTest(prime, x))
return false;
}
return true;
}
int32_t millerRabin(uint8_t* n){
//Most memory requirement part. mem=8*NUMLEN
#if RSADEBUG==1
USART0_SendStr("Start MR test:\n");
#endif
if(n[0]&1==0)
return 0;
uint32_t t=0;
int32_t i=0,k;
uint8_t temp;
uint8_t s[NUMLEN];
uint8_t a[NUMLEN];
int32_t next=0;
bigCopy(s,n);
s[0]^=1;//s=s-1
while(!s[i]){
++i;
t+=8;
}
temp=s[i];
while((temp&1)==0){
++t;
temp>>=1;
}
bigRShift(s,t);
k=0;
while(k<MILLER_RABIN_K){
#if RSADEBUG==1
USART0_SendByte('.');
#endif
n[0]|=1;
bigRandom(a,n);
bigExp(a,s,n);//a=a**s mod n
n[0]^=1;
if(!(bigIsOne(a)||bigEqual(a,n))){
next=0;
for(i=0;(i<t-1)&&!next;++i){
n[0]|=1;
bigMul(a,a,n);
if(bigIsOne(a)){
#if RSADEBUG==1
USART0_SendByte(' ');
#endif
return 0;
}
n[0]^=1;
if(bigEqual(a,n))
next=1;
}
if(!next){
#if RSADEBUG==1
USART0_SendByte(' ');
#endif
return 0;
}
}
k+=2;
}
#if RSADEBUG==1
USART0_SendStr("\n");
#endif
n[0]|=1;
return 1;
}