System.arraycopy(k, k.length-bytes.length, bytes, 0, bytes.length);
System.arraycopy(vals, vals.length-bytes.length, bytes, 0, bytes.length);
    private void testECDSA239bitPrime()    {        BigInteger r = new BigInteger("308636143175167811492622547300668018854959378758531778147462058306432176");        BigInteger s = new BigInteger("323813553209797357708078776831250505931891051755007842781978505179448783");        SecureRandom    k = new SecureRandom()        {            public void nextBytes(byte[] bytes)            {                byte[] k = new BigInteger("700000017569056646655505781757157107570501575775705779575555657156756655").toByteArray();                System.arraycopy(k, k.length-bytes.length, bytes, 0, bytes.length);            }        };        ECCurve.Fp curve = new ECCurve.Fp(            new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q            new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a            new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b        ECDomainParameters params = new ECDomainParameters(            curve,            curve.decodePoint(Hex.decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G            new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307")); // n        ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(            new BigInteger("876300101507107567501066130761671078357010671067781776716671676178726717"), // d            params);        ECDSASigner ecdsa = new ECDSASigner();        ParametersWithRandom param = new ParametersWithRandom(priKey, k);        ecdsa.init(true, param);        byte[] message = new BigInteger("968236873715988614170569073515315707566766479517").toByteArray();        BigInteger[] sig = ecdsa.generateSignature(message);        if (!r.equals(sig[0]))        {            fail("r component wrong." + System.getProperty("line.separator")                + " expecting: " + r + System.getProperty("line.separator")                + " got      : " + sig[0]);        }        if (!s.equals(sig[1]))        {            fail("s component wrong." + System.getProperty("line.separator")                + " expecting: " + s + System.getProperty("line.separator")                + " got      : " + sig[1]);        }        // Verify the signature        ECPublicKeyParameters pubKey = new ECPublicKeyParameters(            curve.decodePoint(Hex.decode("025b6dc53bc61a2548ffb0f671472de6c9521a9d2d2534e65abfcbd5fe0c70")), // Q            params);        ecdsa.init(false, pubKey);        if (!ecdsa.verifySignature(message, sig[0], sig[1]))        {            fail("signature fails");        }    }