/**
* A random number is generated until a probable prime number is found.
*
* @see BigInteger#BigInteger(int,int,Random)
* @see BigInteger#probablePrime(int,Random)
* @see #isProbablePrime(BigInteger, int)
*/
internal static BigInteger consBigInteger(int bitLength, int certainty, java.util.Random rnd)
{
// PRE: bitLength >= 2;
// For small numbers get a random prime from the prime table
if (bitLength <= 10) {
int[] rp = offsetPrimes[bitLength];
return BIprimes[rp[0] + rnd.nextInt(rp[1])];
}
int shiftCount = (-bitLength) & 31;
int last = (bitLength + 31) >> 5;
BigInteger n = new BigInteger(1, last, new int[last]);
last--;
do {// To fill the array with random integers
for (int i = 0; i < n.numberLength; i++) {
n.digits[i] = rnd.nextInt();
}
// To fix to the correct bitLength
n.digits[last] = (int)((long)n.digits[last] | (long)(0x80000000));
n.digits[last] = java.dotnet.lang.Operator.shiftRightUnsignet(n.digits[last], shiftCount);
// To create an odd number
n.digits[0] |= 1;
} while (!isProbablePrime(n, certainty));
return n;
}
