Examples with EllipticCurve java.security.spec.EllipticCurve used on opensource projects

Example 16 with EllipticCurve

use of java.security.spec.EllipticCurve in project protools by SeanDragon.

the class ToolECDSA method initKey.

/**
 * 初始化密钥
 *
 * @return Map 密钥Map
 *
 * @throws Exception
 */
public static Map<String, Object> initKey() throws NoSuchAlgorithmException, InvalidAlgorithmParameterException {
    // 加入BouncyCastleProvider支持
    Security.addProvider(new BouncyCastleProvider());
    BigInteger p = new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839");
    ECFieldFp ecFieldFp = new ECFieldFp(p);
    BigInteger a = new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16);
    BigInteger b = new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16);
    EllipticCurve ellipticCurve = new EllipticCurve(ecFieldFp, a, b);
    BigInteger x = new BigInteger("110282003749548856476348533541186204577905061504881242240149511594420911");
    BigInteger y = new BigInteger("869078407435509378747351873793058868500210384946040694651368759217025454");
    ECPoint g = new ECPoint(x, y);
    BigInteger n = new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307");
    ECParameterSpec ecParameterSpec = new ECParameterSpec(ellipticCurve, g, n, 1);
    // 实例化密钥对儿生成器
    KeyPairGenerator kpg = KeyPairGenerator.getInstance(KEY_ALGORITHM);
    // 初始化密钥对儿生成器
    kpg.initialize(ecParameterSpec, new SecureRandom());
    // 生成密钥对儿
    KeyPair keypair = kpg.generateKeyPair();
    ECPublicKey publicKey = (ECPublicKey) keypair.getPublic();
    ECPrivateKey privateKey = (ECPrivateKey) keypair.getPrivate();
    // 封装密钥
    Map<String, Object> map = Maps.newHashMapWithExpectedSize(2);
    map.put(PUBLIC_KEY, publicKey);
    map.put(PRIVATE_KEY, privateKey);
    return map;
}

Example 17 with EllipticCurve

use of java.security.spec.EllipticCurve in project tink by google.

the class EllipticCurves method validateSharedSecret.

/**
 * Checks that the shared secret is on the curve of the private key, to prevent arithmetic errors
 * or fault attacks.
 */
private static void validateSharedSecret(byte[] secret, ECPrivateKey privateKey) throws GeneralSecurityException {
    EllipticCurve privateKeyCurve = privateKey.getParams().getCurve();
    BigInteger x = new BigInteger(1, secret);
    if (x.signum() == -1 || x.compareTo(getModulus(privateKeyCurve)) != -1) {
        throw new GeneralSecurityException("shared secret is out of range");
    }
    // This will throw if x is not a valid coordinate.
    getY(x, true, /* lsb, doesn't matter here */
    privateKeyCurve);
}

Example 18 with EllipticCurve

use of java.security.spec.EllipticCurve in project tink by google.

the class EllipticCurvesTest method testPointEncode.

@Test
public void testPointEncode() throws Exception {
    for (TestVector2 test : testVectors2) {
        EllipticCurve curve = EllipticCurves.getCurveSpec(test.curve).getCurve();
        ECPoint p = new ECPoint(test.x, test.y);
        byte[] encoded = EllipticCurves.pointEncode(curve, test.format, p);
        assertEquals(TestUtil.hexEncode(encoded), TestUtil.hexEncode(test.encoded));
    }
}

Example 19 with EllipticCurve

use of java.security.spec.EllipticCurve in project jmulticard by ctt-gob-es.

the class JseCryptoHelper method getPrime.

private static BigInteger getPrime(final ECParameterSpec params) {
    if (params == null) {
        throw new IllegalArgumentException(// $NON-NLS-1$
        "Los parametros no pueden ser nulos");
    }
    final EllipticCurve curve = params.getCurve();
    final ECField field = curve.getField();
    if (!(field instanceof ECFieldFp)) {
        throw new IllegalStateException(// $NON-NLS-1$
        "Solo se soporta 'ECFieldFp' y se proporciono  " + field.getClass().getCanonicalName());
    }
    return ((ECFieldFp) field).getP();
}

Example 20 with EllipticCurve

use of java.security.spec.EllipticCurve in project wycheproof by google.

the class EcdhTest method testDistinctCurves.

@SuppressWarnings("InsecureCryptoUsage")
public void testDistinctCurves(String algorithm, ECPrivateKey priv, ECPublicKey pub) throws Exception {
    KeyAgreement kaA;
    try {
        kaA = KeyAgreement.getInstance(algorithm);
    } catch (NoSuchAlgorithmException ex) {
        System.out.println("Algorithm not supported: " + algorithm);
        return;
    }
    byte[] shared;
    try {
        kaA.init(priv);
        kaA.doPhase(pub, true);
        shared = kaA.generateSecret();
    } catch (InvalidKeyException ex) {
        // This is expected.
        return;
    }
    // Printing some information to determine what might have gone wrong:
    // E.g., if the generated secret is the same as the x-coordinate of the public key
    // then it is likely that the ECDH computation was using a fake group with small order.
    // Such a situation is probably exploitable.
    // This probably is exploitable. If the curve of the private key was used for the ECDH
    // then the generated secret and the x-coordinate of the public key are likely
    // distinct.
    EllipticCurve pubCurve = pub.getParams().getCurve();
    EllipticCurve privCurve = priv.getParams().getCurve();
    ECPoint pubW = pub.getW();
    System.out.println("testDistinctCurves: algorithm=" + algorithm);
    System.out.println("Private key: a=" + privCurve.getA() + " b=" + privCurve.getB() + " p" + EcUtil.getModulus(privCurve));
    System.out.println("        s =" + priv.getS());
    System.out.println("Public key: a=" + pubCurve.getA() + " b=" + pubCurve.getB() + " p" + EcUtil.getModulus(pubCurve));
    System.out.println("        w = (" + pubW.getAffineX() + ", " + pubW.getAffineY() + ")");
    System.out.println("          = (" + pubW.getAffineX().toString(16) + ", " + pubW.getAffineY().toString(16) + ")");
    System.out.println("generated shared secret:" + TestUtil.bytesToHex(shared));
    fail("Generated secret with distinct Curves using " + algorithm);
}