C++

Generating Repeatable Random Data for Testing/Debugging

See more PRNG Examples

Demonstrates how to use the Fortuna PRNG to generate random-looking but repeatable non-random data for the purpose of testing and debugging. C++

#include <CkPrng.h>

void ChilkatSample(void)
    {
    bool success = false;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    success = false;

    CkPrng fortuna;

    // Normally an application would seed the PRNG with entropy from
    // some real random source.  However, sometimes we want the same
    // random sequence of bytes for testing and debugging purposes.
    // This a reason why GetEntropy and AddEntropy are two different methods.
    // An application could omit the call to GetEntropy, and instead pass
    // non-random data to AddEntropy. For example:

    // Seed the PRNG with non-entropy, so we get a repeatable sequence.
    // Note: AddEntropy can be called any number of times.
    success = fortuna.AddEntropy("01020304","hex");
    success = fortuna.AddEntropy("hello world","ascii");

    // Generate some random data:
    const char *strRandHex = fortuna.genRandom(16,"hex");
    const char *strRandBase64 = fortuna.genRandom(22,"base64");
    const char *strRandBase58 = fortuna.genRandom(32,"base58");

    std::cout << "hex random bytes: " << strRandHex << "\r\n";
    std::cout << "base64 random bytes: " << strRandBase64 << "\r\n";
    std::cout << "base58 random bytes: " << strRandBase58 << "\r\n";

    // Try it again with a different object to verify that the same results are obtained:
    CkPrng fortuna2;

    success = fortuna2.AddEntropy("01020304","hex");
    success = fortuna2.AddEntropy("hello world","ascii");

    strRandHex = fortuna2.genRandom(16,"hex");
    strRandBase64 = fortuna2.genRandom(22,"base64");
    strRandBase58 = fortuna2.genRandom(32,"base58");

    std::cout << "hex random bytes: " << strRandHex << "\r\n";
    std::cout << "base64 random bytes: " << strRandBase64 << "\r\n";
    std::cout << "base58 random bytes: " << strRandBase58 << "\r\n";
    }