Java Code Examples for java.security.interfaces.ECPrivateKey#getS()

/**
 * Tests key generation for given parameters. The test can be skipped if the curve is not a
 * standard curve.
 */
void testKeyGeneration(ECParameterSpec ecParams, boolean isStandard) throws Exception {
  KeyPairGenerator keyGen = KeyPairGenerator.getInstance("EC");
  KeyPair keyPair;
  try {
    keyGen.initialize(ecParams);
    keyPair = keyGen.generateKeyPair();
  } catch (InvalidAlgorithmParameterException ex) {
    if (!isStandard) {
      return;
    }
    throw ex;
  }
  ECPublicKey pub = (ECPublicKey) keyPair.getPublic();
  ECPrivateKey priv = (ECPrivateKey) keyPair.getPrivate();
  EcUtil.checkPublicKey(pub);
  BigInteger s = priv.getS();
  // Check the length of s. Could fail with probability 2^{-32}.
  assertTrue(s.bitLength() >= EcUtil.fieldSizeInBits(ecParams.getCurve()) - 32);
  // TODO(bleichen): correct curve?
  // TODO(bleichen): use RandomUtil
}
 

/** Extract the k that was used to sign the signature. */
BigInteger extractK(byte[] signature, BigInteger h, ECPrivateKey priv) throws Exception {
  BigInteger x = priv.getS();
  BigInteger n = priv.getParams().getOrder();
  BigInteger r = extractR(signature);
  BigInteger s = extractS(signature);
  BigInteger k = x.multiply(r).add(h).multiply(s.modInverse(n)).mod(n);
  return k;
}
 

protected static byte[] decrypt(final byte[] ciphertext, final PrivateKey privateKey)
		throws BadPaddingException, IllegalBlockSizeException {
	if (privateKey instanceof ECPrivateKey) {
		final ECPrivateKey ecPrivateKey = (ECPrivateKey) privateKey;
		final BigInteger privateKeyInt = ecPrivateKey.getS();
		return decrypt(ciphertext, privateKeyInt);
	} else {
		throw new IllegalArgumentException("Key type must be ECPublicKey!");
	}
}
 

public JCEECPrivateKey(
    ECPrivateKey    key)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
}
 

public BCDSTU4145PrivateKey(
    ECPrivateKey key)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
}
 

public BCECPrivateKey(
    ECPrivateKey key,
    ProviderConfiguration configuration)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
    this.configuration = configuration;
}
 

public BCECGOST3410PrivateKey(
    ECPrivateKey key)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
}
 

public JCEECPrivateKey(
    ECPrivateKey    key)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
}
 

public BCDSTU4145PrivateKey(
    ECPrivateKey key)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
}
 

public BCECPrivateKey(
    ECPrivateKey key,
    ProviderConfiguration configuration)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
    this.configuration = configuration;
}
 

public BCECGOST3410PrivateKey(
    ECPrivateKey key)
{
    this.d = key.getS();
    this.algorithm = key.getAlgorithm();
    this.ecSpec = key.getParams();
}
 

public static EcPrivateKeyDef from(ECPrivateKey key) {
  return new EcPrivateKeyDef(EcDomainDef.from(key.getParams()), key.getS(), key);
}
 

static byte[] generateECBlob(Key k) {

        int keyBitLength = KeyUtil.getKeySize(k);
        int keyLen = (keyBitLength + 7) / 8;
        boolean isPrivate = k instanceof ECPrivateKey;

        byte[] keyBlob = new byte[8 + keyLen * (isPrivate ? 3 : 2)];
        keyBlob[0] = 'E';
        keyBlob[1] = 'C';
        keyBlob[2] = 'S';
        if (isPrivate) {
            keyBlob[3] = (byte) (keyBitLength == 256 ? '2'
                    : (keyBitLength == 384 ? '4' : '6'));
        } else {
            keyBlob[3] = (byte) (keyBitLength == 256 ? '1'
                    : (keyBitLength == 384 ? '3' : '5'));
        }
        BigInteger x;
        BigInteger y;
        // Fill the array in reverse order (s -> y -> x -> len) in case
        // one BigInteger encoding has an extra 0 at the beginning
        if (isPrivate) {
            // We can keep X and Y zero and it still works
            ECPrivateKey prk = (ECPrivateKey)k;
            BigInteger s = prk.getS();
            byte[] bs = s.toByteArray();
            System.arraycopy(
                    bs, 0,
                    keyBlob, 8 + keyLen + keyLen + keyLen - bs.length,
                    bs.length);
        } else {
            ECPublicKey puk = (ECPublicKey)k;
            x = puk.getW().getAffineX();
            y = puk.getW().getAffineY();
            byte[] by = y.toByteArray();
            System.arraycopy(by, 0, keyBlob, 8 + keyLen + keyLen - by.length,
                    by.length);
            byte[] bx = x.toByteArray();
            System.arraycopy(bx, 0, keyBlob, 8 + keyLen - bx.length, bx.length);
        }
        keyBlob[4] = (byte) keyLen;
        keyBlob[5] = keyBlob[6] = keyBlob[7] = 0;
        return keyBlob;
    }
 

/**
 * Checks if the private key is a valid key (according to requirement [V2G2-823]) for the received contract 
 * certificate before saving it to the keystore.
 * @param privateKey The private key corresponding to the contract certificate
 * @param contractCertChain The received contract certificate chain 
 * @return True, if the private key is a valid key, false otherwise.
 */
private static boolean isPrivateKeyValid(ECPrivateKey privateKey, CertificateChainType contractCertChain) {
	AlgorithmParameters parameters;
	
	try {
		parameters = AlgorithmParameters.getInstance("EC");
		parameters.init(new ECGenParameterSpec("secp256r1"));
		
		ECParameterSpec ecParameterSpec = parameters.getParameterSpec(ECParameterSpec.class);
		
		// Now we need to check if the private key is correct (see requirement [V2G2-823]) 
		BigInteger order = ecParameterSpec.getOrder();
		ECPoint basePoint = ecParameterSpec.getGenerator();
		BigInteger privateKeyValue = privateKey.getS();
		X509Certificate contractCert = getCertificate(contractCertChain.getCertificate());
		ECPublicKey publicKey = (ECPublicKey) contractCert.getPublicKey();
		
		// 1. check
		if (privateKeyValue.compareTo(order) != -1) {
			getLogger().error("Validation of private key failed: its value is not strictly smaller than the "
							+ "order of the base point");
			return false;
		}
		
		// 2. check
		/*
		 * TODO: 
		 * No idea how to check for 
		 * "multiplication of the base point with this value must generate a key matching the public key of 
		 * the contract certificate"
		 * "this value" = value of private key
		 * -> some more expert knowledge on the arithmetic of elliptic curves is needed to tackle this!
		 */
		
	} catch (NoSuchAlgorithmException | InvalidParameterSpecException e) {
		getLogger().error(e.getClass().getSimpleName() + " occurred when trying to get private key from raw bytes", e);
		return false;
	}
	
	return true;
}
 

static byte[] generateECBlob(Key k) {

        int keyBitLength = KeyUtil.getKeySize(k);
        int keyLen = (keyBitLength + 7) / 8;
        boolean isPrivate = k instanceof ECPrivateKey;

        byte[] keyBlob = new byte[8 + keyLen * (isPrivate ? 3 : 2)];
        keyBlob[0] = 'E';
        keyBlob[1] = 'C';
        keyBlob[2] = 'S';
        if (isPrivate) {
            keyBlob[3] = (byte) (keyBitLength == 256 ? '2'
                    : (keyBitLength == 384 ? '4' : '6'));
        } else {
            keyBlob[3] = (byte) (keyBitLength == 256 ? '1'
                    : (keyBitLength == 384 ? '3' : '5'));
        }
        BigInteger x;
        BigInteger y;
        // Fill the array in reverse order (s -> y -> x -> len) in case
        // one BigInteger encoding has an extra 0 at the beginning
        if (isPrivate) {
            // We can keep X and Y zero and it still works
            ECPrivateKey prk = (ECPrivateKey)k;
            BigInteger s = prk.getS();
            byte[] bs = s.toByteArray();
            System.arraycopy(
                    bs, 0,
                    keyBlob, 8 + keyLen + keyLen + keyLen - bs.length,
                    bs.length);
        } else {
            ECPublicKey puk = (ECPublicKey)k;
            x = puk.getW().getAffineX();
            y = puk.getW().getAffineY();
            byte[] by = y.toByteArray();
            System.arraycopy(by, 0, keyBlob, 8 + keyLen + keyLen - by.length,
                    by.length);
            byte[] bx = x.toByteArray();
            System.arraycopy(bx, 0, keyBlob, 8 + keyLen - bx.length, bx.length);
        }
        keyBlob[4] = (byte) keyLen;
        keyBlob[5] = keyBlob[6] = keyBlob[7] = 0;
        return keyBlob;
    }