(Java) Fortuna PRNG Generate Random Encoded

Demonstrates how to generate random bytes using the Fortuna PRNG. The random bytes are returned in an encoded string (using an encoding such as hex, base64, base58, etc.)

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux Java Libs for Android

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // All Chilkat classes can be unlocked at once at the beginning of a program
    // by calling UnlockBundle.  It requires a Bundle unlock code.
    CkGlobal chilkatGlob = new CkGlobal();
    boolean success = chilkatGlob.UnlockBundle("Anything for 30-day trial.");
    if (success != true) {
        System.out.println(chilkatGlob.lastErrorText());
        return;
        }

    CkPrng fortuna = new CkPrng();

    // Before beginning to generate random data, 
    // the PRNG (Pseudo Random Number Generator) should
    // be seeded with real random data (also known as "entropy").

    // Note: Accumulating real random data can be difficult
    // and time-consuming to collect.  It is for this reason
    // that pseudorandom data (i.e. a PRNG) is used.  The pseudorandom data generator
    // is seeded with entropy.  In addition, new entropy can (and should)
    // be periodically added as more pseudorandom data is generated.

    // Get 32 bytes of system entropy.  On Linux/Unix systems, this reads
    // from /dev/random.  On MS Windows systems, it uses the Crypto API's 
    // CryptGenRandom function.
    String strEntropy = fortuna.getEntropy(32,"hex");
    if (fortuna.get_LastMethodSuccess() != true) {
        System.out.println(fortuna.lastErrorText());
        return;
        }

    // Seed the PRNG with this entropy:
    success = fortuna.AddEntropy(strEntropy,"hex");
    if (success != true) {
        System.out.println(fortuna.lastErrorText());
        return;
        }

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

    System.out.println("hex random bytes: " + strRandHex);
    System.out.println("base64 random bytes: " + strRandBase64);
    System.out.println("base58 random bytes: " + strRandBase58);
  }
}