Hash a Password with Argon2 (Tuned Options)

Demonstrates Crypt2.Argon2HashPassword with explicit options: the cost parameters, saltLen (how many random salt bytes to generate when no salt is given), and an optional secret (pepper).

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Crypt2;
import com.chilkatsoft.chilkat2.JsonObject;

public class ChilkatExample {

    public static void main(String[] args) {
        Crypt2 crypt = new Crypt2();

        // The password should come from a secure source rather than being hard-coded.
        String password = "correct horse battery staple";

        // The Argon2 options are the same members as Argon2DeriveKey, except the salt is optional for
        // hashing.  When no "salt" is given, a random salt is generated; "saltLen" (default 16, range 8..1024)
        // sets how many random bytes to use.
        JsonObject json = new JsonObject();
        json.updateString("variant", "argon2id");
        json.updateInt("memoryCostKb", 131072);
        json.updateInt("iterations", 4);
        json.updateInt("parallelism", 2);
        json.updateInt("saltLen", 16);

        // A secret (pepper) and/or ad may be used, but neither is stored in the returned PHC string.  The
        // same values must be supplied to Argon2VerifyPassword for the password to verify.
        json.updateString("secret", "application-wide-pepper");
        json.updateString("secretEncoding", "utf-8");

        String phcHash;
        try {
            phcHash = crypt.argon2HashPassword(password, json.emit());
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        System.out.println(phcHash);
    }
}