private byte[] Process(BitBlock[] subKeys, byte[] next8ByteBlock)
{
BitBlock next64BitBlock = new BitBlock(next8ByteBlock);
BitBlock initialPermutation_Output = InitialPermutation(next64BitBlock);
BitBlock leftSide = initialPermutation_Output.LeftSide();
BitBlock rightSide = initialPermutation_Output.RightSide();
// 16 Rounds of Encryption/Decryption
for (int i = 0; i <= 15; i++)
{
BitBlock F_Output = F(rightSide, subKeys[i]);
BitBlock tempRightSide = leftSide ^ F_Output;
leftSide = rightSide;
rightSide = tempRightSide;
}
BitBlock finalPermutation_Output = FinalPermutation(rightSide + leftSide);
byte[] byteArray = BitBlock.ConvertToByteArray(finalPermutation_Output);
return(byteArray);
}
private BigInteger GenerateRandomPrime(int desiredSize)
{
// Create empty blocks for our prime
BitBlock potentialPrime_asBitBlock = new BitBlock(desiredSize);
BigInteger potentialPrime;
do
{
// Convert potential prime to byte array
byte[] potentialPrime_asByteArray = BitBlock.ConvertToByteArray(potentialPrime_asBitBlock);
// Fill potential prime with random bits
cryptoServiceProvider.GetBytes(potentialPrime_asByteArray);
// Convert potential prime to Big Integers
potentialPrime = new BigInteger(potentialPrime_asByteArray);
// If we created negative potential prime, change to positive
if (potentialPrime.Sign == -1)
{
potentialPrime *= -1;
}
} while (!isPrime(potentialPrime, securityToken));
return(potentialPrime);
}
private BigInteger GenerateP(int desiredSize)
{
// Create 2 empty blocks for p and q
BitBlock p_asBitBlock = new BitBlock(desiredSize);
BigInteger p = 0;
bool isPPrime = false;
do
{
// Convert p to byte array
byte[] p_asByteArray = BitBlock.ConvertToByteArray(p_asBitBlock);
// Fill p with random bits
cryptoServiceProvider.GetBytes(p_asByteArray);
// Convert p to Big Integer
p = new BigInteger(p_asByteArray);
// If we created negative p/q, change to positive
if (p.Sign == -1)
{
p *= -1;
}
// Primality Test
switch (this.primalityTestToUse)
{
case PrimalityTest.Fermat:
isPPrime = Helpers.FermatPrimalityTest(p, this.securityToken);
break;
case PrimalityTest.RabinMiller:
isPPrime = Helpers.MillerRabinPrimalityTest(p, this.securityToken);
break;
}
} while (!isPPrime);
return(p);
}