How to use RabinMillerTest() in CryptoPP? - c++

Question

Can anyone share an example of RabinMillerTest() that works? My googlefu is sadly lacking.
Here is my test code:
#include "integer.h"
#include "nbtheory.h"
#include "cryptlib.h"
#include "osrng.h"
#include <iostream>
int main(int argc,char *argv[])
{
CryptoPP::RandomNumberGenerator rng;
CryptoPP::Integer a("123456789");
CryptoPP::Integer b;
std::cout << a << std::endl;
std::cout << "is prime: " << IsPrime(a) << std::endl;
b=a+CryptoPP::Integer::Two();
std::cout << b << std::endl;
std::cout << "is prime: " << IsPrime(b) << std::endl;
int r=RabinMillerTest(rng,&b,2);
std::cout << "RabinMiller: " << r <<std::endl;
}
Here is the build command:
g++ bignum.cpp -I. -fpermissive libcryptopp.a
The only example I could find is here:
http://www.cryptopp.com/wiki/Diffie-Hellman
My code crashes every time I run it, and one crash was so bad I had to cold boot to recover. If I remove the call to RabinMillerTest() then it runs fine. I suspect a problem with C++ syntax is the culprit, but I just don't see it. Since I can't use it properly, I am currently stripping the guts of the RabinMillerTest() function to use separately.

Answer 1

You're using the wrong signature for MillerRabinTest. Here's what it is (from nbtheory.h):
CRYPTOPP_DLL bool CRYPTOPP_API RabinMillerTest(RandomNumberGenerator &rng,
const Integer &w, unsigned int rounds);
Instead of:
int r=RabinMillerTest(rng,&b,2);
Try:
bool b=RabinMillerTest(rng, b, 2);
There's also a discussion of Miller-Rabin round counts on the Cryptography Stack Exchange at Trial divisions before Miller-Rabin checks?. It was written with OpenSSL and Crypto++ in mind.

Answer 2

This was the answer edited into the question. Adding as a separate answer block. Credit goes to user3920315.
UPDATE: I got it to work. Here is the working code:
#include "integer.h"
#include "nbtheory.h"
#include "cryptlib.h"
#include "osrng.h"
#include <iostream>
int main(int argc,char *argv[])
{
//CryptoPP::RandomNumberGenerator rng;
CryptoPP::NonblockingRng rng;
CryptoPP::Integer a("123456789");
CryptoPP::Integer b;
std::cout << a << std::endl;
std::cout << "is prime: " << IsPrime(a) << std::endl;
b=a+CryptoPP::Integer::Two();
std::cout << b << std::endl;
std::cout << "is prime: " << IsPrime(b) << std::endl;
bool r=RabinMillerTest(rng,b,2);
std::cout << "RabinMiller: " << r <<std::endl;
}
I changed the call to RabinMillerTest() but the resulting executable would still crash.
When I changed the random number generator to a class that inherits from RandomNumberGenerator, then it works.