java.security.spec.EllipticCurve Java Exaples

Source File: ECOperations.java From dragonwell8_jdk with GNU General Public License v2.0

7 votes

public static Optional<ECOperations> forParameters(ECParameterSpec params) {

        EllipticCurve curve = params.getCurve();
        if (!(curve.getField() instanceof ECFieldFp)) {
            return Optional.empty();
        }
        ECFieldFp primeField = (ECFieldFp) curve.getField();

        BigInteger three = BigInteger.valueOf(3);
        if (!primeField.getP().subtract(curve.getA()).equals(three)) {
            return Optional.empty();
        }
        IntegerFieldModuloP field = fields.get(primeField.getP());
        if (field == null) {
            return Optional.empty();
        }

        IntegerFieldModuloP orderField = orderFields.get(params.getOrder());
        if (orderField == null) {
            return Optional.empty();
        }

        ImmutableIntegerModuloP b = field.getElement(curve.getB());
        ECOperations ecOps = new ECOperations(b, orderField);
        return Optional.of(ecOps);
    }

Source File: JCEECPrivateKey.java From ripple-lib-java with ISC License

6 votes

public JCEECPrivateKey(
    String              algorithm,
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec     spec)
{
    this.algorithm = algorithm;
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }
}

Source File: ECOperations.java From TencentKona-8 with GNU General Public License v2.0

6 votes

public static Optional<ECOperations> forParameters(ECParameterSpec params) {

        EllipticCurve curve = params.getCurve();
        if (!(curve.getField() instanceof ECFieldFp)) {
            return Optional.empty();
        }
        ECFieldFp primeField = (ECFieldFp) curve.getField();

        BigInteger three = BigInteger.valueOf(3);
        if (!primeField.getP().subtract(curve.getA()).equals(three)) {
            return Optional.empty();
        }
        IntegerFieldModuloP field = fields.get(primeField.getP());
        if (field == null) {
            return Optional.empty();
        }

        IntegerFieldModuloP orderField = orderFields.get(params.getOrder());
        if (orderField == null) {
            return Optional.empty();
        }

        ImmutableIntegerModuloP b = field.getElement(curve.getB());
        ECOperations ecOps = new ECOperations(b, orderField);
        return Optional.of(ecOps);
    }

Source File: DOMKeyValue.java From openjdk-jdk8u with GNU General Public License v2.0

6 votes

private static ECPoint decodePoint(byte[] data, EllipticCurve curve)
        throws IOException {
    if ((data.length == 0) || (data[0] != 4)) {
        throw new IOException("Only uncompressed point format " +
                              "supported");
    }
    // Per ANSI X9.62, an encoded point is a 1 byte type followed by
    // ceiling(log base 2 field-size / 8) bytes of x and the same of y.
    int n = (data.length - 1) / 2;
    if (n != ((curve.getField().getFieldSize() + 7) >> 3)) {
        throw new IOException("Point does not match field size");
    }

    byte[] xb = Arrays.copyOfRange(data, 1, 1 + n);
    byte[] yb = Arrays.copyOfRange(data, n + 1, n + 1 + n);

    return new ECPoint(new BigInteger(1, xb), new BigInteger(1, yb));
}

Source File: BCECPrivateKey.java From RipplePower with Apache License 2.0

6 votes

public BCECPrivateKey(
    String algorithm,
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec spec,
    ProviderConfiguration configuration)
{
    this.algorithm = algorithm;
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }

    this.configuration = configuration;
}

Source File: BCDSTU4145PrivateKey.java From ripple-lib-java with ISC License

6 votes

public BCDSTU4145PrivateKey(
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec spec)
{
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }
}

Source File: ECOperations.java From openjdk-jdk8u with GNU General Public License v2.0

6 votes

public static Optional<ECOperations> forParameters(ECParameterSpec params) {

        EllipticCurve curve = params.getCurve();
        if (!(curve.getField() instanceof ECFieldFp)) {
            return Optional.empty();
        }
        ECFieldFp primeField = (ECFieldFp) curve.getField();

        BigInteger three = BigInteger.valueOf(3);
        if (!primeField.getP().subtract(curve.getA()).equals(three)) {
            return Optional.empty();
        }
        IntegerFieldModuloP field = fields.get(primeField.getP());
        if (field == null) {
            return Optional.empty();
        }

        IntegerFieldModuloP orderField = orderFields.get(params.getOrder());
        if (orderField == null) {
            return Optional.empty();
        }

        ImmutableIntegerModuloP b = field.getElement(curve.getB());
        ECOperations ecOps = new ECOperations(b, orderField);
        return Optional.of(ecOps);
    }

Source File: TPMAuthenticator.java From webauthn4j with Apache License 2.0

6 votes

private TPMTPublic createTPMTPublic(PublicKey credentialPublicKey) {
    TPMIAlgPublic type = null;
    TPMIAlgHash nameAlg = TPMIAlgHash.TPM_ALG_SHA256;
    TPMAObject objectAttributes = new TPMAObject(394354);
    byte[] authPolicy = Base64UrlUtil.decode("nf_L82w4OuaZ-5ho3G3LidcVOIS-KAOSLBJBWL-tIq4");
    TPMUPublicId unique = null;
    TPMUPublicParms parameters = null;
    if (credentialPublicKey instanceof ECPublicKey) {
        ECPublicKey ecPublicKey = (ECPublicKey) credentialPublicKey;
        EllipticCurve curve = ecPublicKey.getParams().getCurve();
        parameters = new TPMSECCParms(
                new byte[2],
                new byte[2],
                TPMEccCurve.create(curve),
                new byte[2]
        );
        type = TPMIAlgPublic.TPM_ALG_ECDSA;
        ECPoint ecPoint = ecPublicKey.getW();
        byte[] x = ecPoint.getAffineX().toByteArray();
        byte[] y = ecPoint.getAffineY().toByteArray();
        unique = new ECCUnique(x, y);
    }
    return new TPMTPublic(type, nameAlg, objectAttributes, authPolicy, parameters, unique);
}

Source File: EC5Util.java From ripple-lib-java with ISC License

6 votes

public static ECCurve convertCurve(
    EllipticCurve ec)
{
    ECField field = ec.getField();
    BigInteger a = ec.getA();
    BigInteger b = ec.getB();

    if (field instanceof ECFieldFp)
    {
        ECCurve.Fp curve = new ECCurve.Fp(((ECFieldFp)field).getP(), a, b);

        if (customCurves.containsKey(curve))
        {
            return (ECCurve)customCurves.get(curve);
        }

        return curve;
    }
    else
    {
        ECFieldF2m fieldF2m = (ECFieldF2m)field;
        int m = fieldF2m.getM();
        int ks[] = ECUtil.convertMidTerms(fieldF2m.getMidTermsOfReductionPolynomial());
        return new ECCurve.F2m(m, ks[0], ks[1], ks[2], a, b); 
    }
}

Source File: BCECPrivateKey.java From ripple-lib-java with ISC License

6 votes

public BCECPrivateKey(
    String algorithm,
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec spec,
    ProviderConfiguration configuration)
{
    this.algorithm = algorithm;
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }

    this.configuration = configuration;
}

Source File: Util.java From julongchain with Apache License 2.0

6 votes

public static ECParameterSpec getECParameterSpec() {
    BigInteger n = new BigInteger(
            "FFFFFFFE" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "7203DF6B" + "21C6052B" + "53BBF409" + "39D54123", 16);
    BigInteger p = new BigInteger(
            "FFFFFFFE" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "00000000" + "FFFFFFFF" + "FFFFFFFF", 16);
    BigInteger a = new BigInteger(
            "FFFFFFFE" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "FFFFFFFF" + "00000000" + "FFFFFFFF" + "FFFFFFFC", 16);
    BigInteger b = new BigInteger(
            "28E9FA9E" + "9D9F5E34" + "4D5A9E4B" + "CF6509A7" + "F39789F5" + "15AB8F92" + "DDBCBD41" + "4D940E93", 16);
    BigInteger gx = new BigInteger(
            "32C4AE2C" + "1F198119" + "5F990446" + "6A39C994" + "8FE30BBF" + "F2660BE1" + "715A4589" + "334C74C7", 16);
    BigInteger gy = new BigInteger(
            "BC3736A2" + "F4F6779C" + "59BDCEE3" + "6B692153" + "D0A9877C" + "C62A4740" + "02DF32E5" + "2139F0A0", 16);

    EllipticCurve ellipticCurve = new EllipticCurve(new ECFieldFp(p), a, b);
    return new ECParameterSpec(ellipticCurve, new ECPoint(gx, gy), n, 1);
}

Source File: BCECGOST3410PublicKey.java From ripple-lib-java with ISC License

6 votes

public BCECGOST3410PublicKey(
    org.ripple.bouncycastle.jce.spec.ECPublicKeySpec spec)
{
    this.q = spec.getQ();

    if (spec.getParams() != null) // can be null if implictlyCa
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        if (q.getCurve() == null)
        {
            org.ripple.bouncycastle.jce.spec.ECParameterSpec s = BouncyCastleProvider.CONFIGURATION.getEcImplicitlyCa();

            q = s.getCurve().createPoint(q.getAffineXCoord().toBigInteger(), q.getAffineYCoord().toBigInteger());
        }
        this.ecSpec = null;
    }
}

Source File: BCECGOST3410PrivateKey.java From ripple-lib-java with ISC License

6 votes

public BCECGOST3410PrivateKey(
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec spec)
{
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }
}

Source File: JCEECPrivateKey.java From RipplePower with Apache License 2.0

6 votes

public JCEECPrivateKey(
    String              algorithm,
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec     spec)
{
    this.algorithm = algorithm;
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }
}

Source File: DOMKeyValue.java From openjdk-jdk9 with GNU General Public License v2.0

6 votes

private static ECPoint decodePoint(byte[] data, EllipticCurve curve)
        throws IOException {
    if ((data.length == 0) || (data[0] != 4)) {
        throw new IOException("Only uncompressed point format " +
                              "supported");
    }
    // Per ANSI X9.62, an encoded point is a 1 byte type followed by
    // ceiling(log base 2 field-size / 8) bytes of x and the same of y.
    int n = (data.length - 1) / 2;
    if (n != ((curve.getField().getFieldSize() + 7) >> 3)) {
        throw new IOException("Point does not match field size");
    }

    byte[] xb = Arrays.copyOfRange(data, 1, 1 + n);
    byte[] yb = Arrays.copyOfRange(data, n + 1, n + 1 + n);

    return new ECPoint(new BigInteger(1, xb), new BigInteger(1, yb));
}

Source File: JCEECPublicKey.java From RipplePower with Apache License 2.0

6 votes

public JCEECPublicKey(
    String              algorithm,
    org.ripple.bouncycastle.jce.spec.ECPublicKeySpec     spec)
{
    this.algorithm = algorithm;
    this.q = spec.getQ();

    if (spec.getParams() != null) // can be null if implictlyCa
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        if (q.getCurve() == null)
        {
            org.ripple.bouncycastle.jce.spec.ECParameterSpec s = BouncyCastleProvider.CONFIGURATION.getEcImplicitlyCa();

            q = s.getCurve().createPoint(q.getAffineXCoord().toBigInteger(), q.getAffineYCoord().toBigInteger(), false);
        }               
        this.ecSpec = null;
    }
}

Source File: BCECGOST3410PublicKey.java From RipplePower with Apache License 2.0

6 votes

public BCECGOST3410PublicKey(
    String algorithm,
    ECPublicKeyParameters params,
    ECParameterSpec spec)
{
    ECDomainParameters dp = params.getParameters();

    this.algorithm = algorithm;
    this.q = params.getQ();

    if (spec == null)
    {
        EllipticCurve ellipticCurve = EC5Util.convertCurve(dp.getCurve(), dp.getSeed());

        this.ecSpec = createSpec(ellipticCurve, dp);
    }
    else
    {
        this.ecSpec = spec;
    }
}

Source File: BCECGOST3410PrivateKey.java From RipplePower with Apache License 2.0

6 votes

public BCECGOST3410PrivateKey(
    org.ripple.bouncycastle.jce.spec.ECPrivateKeySpec spec)
{
    this.d = spec.getD();

    if (spec.getParams() != null) // can be null if implicitlyCA
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve;

        ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        this.ecSpec = null;
    }
}

Source File: EcdhTest.java From wycheproof with Apache License 2.0

6 votes

/**
 * Returns this key as ECPublicKeySpec or null if the key cannot be represented as
 * ECPublicKeySpec. The later happens for example if the order of cofactor are not positive.
 */
public ECPublicKeySpec getSpec() {
  try {
    ECFieldFp fp = new ECFieldFp(p);
    EllipticCurve curve = new EllipticCurve(fp, a, b);
    ECPoint g = new ECPoint(gx, gy);
    // ECParameterSpec requires that the cofactor h is specified.
    if (h == null) {
      return null;
    }
    ECParameterSpec params = new ECParameterSpec(curve, g, n, h);
    ECPoint pubPoint = new ECPoint(pubx, puby);
    ECPublicKeySpec pub = new ECPublicKeySpec(pubPoint, params);
    return pub;
  } catch (Exception ex) {
    System.out.println(comment + " throws " + ex.toString());
    return null;
  }
}

Source File: EcUtil.java From wycheproof with Apache License 2.0

6 votes

public static ECParameterSpec getNistCurveSpec(
    String decimalP, String decimalN, String hexB, String hexGX, String hexGY) {
  final BigInteger p = new BigInteger(decimalP);
  final BigInteger n = new BigInteger(decimalN);
  final BigInteger three = new BigInteger("3");
  final BigInteger a = p.subtract(three);
  final BigInteger b = new BigInteger(hexB, 16);
  final BigInteger gx = new BigInteger(hexGX, 16);
  final BigInteger gy = new BigInteger(hexGY, 16);
  final int h = 1;
  ECFieldFp fp = new ECFieldFp(p);
  java.security.spec.EllipticCurve curveSpec = new java.security.spec.EllipticCurve(fp, a, b);
  ECPoint g = new ECPoint(gx, gy);
  ECParameterSpec ecSpec = new ECParameterSpec(curveSpec, g, n, h);
  return ecSpec;
}

Source File: EcUtil.java From wycheproof with Apache License 2.0

6 votes

public static ECParameterSpec getBrainpoolP224r1Params() {
  // name = "brainpoolP224r1",
  // oid = '2b2403030208010105',
  // ref = "RFC 5639",
  BigInteger p = new BigInteger("D7C134AA264366862A18302575D1D787B09F075797DA89F57EC8C0FF", 16);
  BigInteger a = new BigInteger("68A5E62CA9CE6C1C299803A6C1530B514E182AD8B0042A59CAD29F43", 16);
  BigInteger b = new BigInteger("2580F63CCFE44138870713B1A92369E33E2135D266DBB372386C400B", 16);
  BigInteger x = new BigInteger("0D9029AD2C7E5CF4340823B2A87DC68C9E4CE3174C1E6EFDEE12C07D", 16);
  BigInteger y = new BigInteger("58AA56F772C0726F24C6B89E4ECDAC24354B9E99CAA3F6D3761402CD", 16);
  BigInteger n = new BigInteger("D7C134AA264366862A18302575D0FB98D116BC4B6DDEBCA3A5A7939F", 16);
  final int h = 1;
  ECFieldFp fp = new ECFieldFp(p);
  EllipticCurve curve = new EllipticCurve(fp, a, b);
  ECPoint g = new ECPoint(x, y);
  return new ECParameterSpec(curve, g, n, h);
}

Source File: EcUtil.java From wycheproof with Apache License 2.0

6 votes

public static ECParameterSpec getBrainpoolP256r1Params() {
  BigInteger p =
      new BigInteger("A9FB57DBA1EEA9BC3E660A909D838D726E3BF623D52620282013481D1F6E5377", 16);
  BigInteger a =
      new BigInteger("7D5A0975FC2C3057EEF67530417AFFE7FB8055C126DC5C6CE94A4B44F330B5D9", 16);
  BigInteger b =
      new BigInteger("26DC5C6CE94A4B44F330B5D9BBD77CBF958416295CF7E1CE6BCCDC18FF8C07B6", 16);
  BigInteger x =
      new BigInteger("8BD2AEB9CB7E57CB2C4B482FFC81B7AFB9DE27E1E3BD23C23A4453BD9ACE3262", 16);
  BigInteger y =
      new BigInteger("547EF835C3DAC4FD97F8461A14611DC9C27745132DED8E545C1D54C72F046997", 16);
  BigInteger n =
      new BigInteger("A9FB57DBA1EEA9BC3E660A909D838D718C397AA3B561A6F7901E0E82974856A7", 16);
  final int h = 1;
  ECFieldFp fp = new ECFieldFp(p);
  EllipticCurve curve = new EllipticCurve(fp, a, b);
  ECPoint g = new ECPoint(x, y);
  return new ECParameterSpec(curve, g, n, h);
}

Source File: BCECPublicKey.java From RipplePower with Apache License 2.0

6 votes

public BCECPublicKey(
    String algorithm,
    ECPublicKeyParameters params,
    ECParameterSpec spec,
    ProviderConfiguration configuration)
{
    ECDomainParameters      dp = params.getParameters();

    this.algorithm = algorithm;
    this.q = params.getQ();

    if (spec == null)
    {
        EllipticCurve ellipticCurve = EC5Util.convertCurve(dp.getCurve(), dp.getSeed());

        this.ecSpec = createSpec(ellipticCurve, dp);
    }
    else
    {
        this.ecSpec = spec;
    }

    this.configuration = configuration;
}

Source File: EcUtil.java From wycheproof with Apache License 2.0

6 votes

/**
 * Checks that a point is on a given elliptic curve. This method implements the partial public key
 * validation routine from Section 5.6.2.6 of NIST SP 800-56A
 * http://csrc.nist.gov/publications/nistpubs/800-56A/SP800-56A_Revision1_Mar08-2007.pdf A partial
 * public key validation is sufficient for curves with cofactor 1. See Section B.3 of
 * http://www.nsa.gov/ia/_files/SuiteB_Implementer_G-113808.pdf The point validations above are
 * taken from recommendations for ECDH, because parameter checks in ECDH are much more important
 * than for the case of ECDSA. Performing this test for ECDSA keys is mainly a sanity check.
 *
 * @param point the point that needs verification
 * @param ec the elliptic curve. This must be a curve over a prime order field.
 * @throws GeneralSecurityException if the field is binary or if the point is not on the curve.
 */
public static void checkPointOnCurve(ECPoint point, EllipticCurve ec)
    throws GeneralSecurityException {
  BigInteger p = getModulus(ec);
  BigInteger x = point.getAffineX();
  BigInteger y = point.getAffineY();
  if (x == null || y == null) {
    throw new GeneralSecurityException("point is at infinity");
  }
  // Check 0 <= x < p and 0 <= y < p.
  if (x.signum() == -1 || x.compareTo(p) != -1) {
    throw new GeneralSecurityException("x is out of range");
  }
  if (y.signum() == -1 || y.compareTo(p) != -1) {
    throw new GeneralSecurityException("y is out of range");
  }
  // Check y^2 == x^3 + a x + b (mod p)
  BigInteger lhs = y.multiply(y).mod(p);
  BigInteger rhs = x.multiply(x).add(ec.getA()).multiply(x).add(ec.getB()).mod(p);
  if (!lhs.equals(rhs)) {
    throw new GeneralSecurityException("Point is not on curve");
  }
}

Source File: EcUtil.java From wycheproof with Apache License 2.0

6 votes

/**
 * Decompress a point
 *
 * @param x The x-coordinate of the point
 * @param bit0 true if the least significant bit of y is set.
 * @param ecParams contains the curve of the point. This must be over a prime order field.
 */
public static ECPoint getPoint(BigInteger x, boolean bit0, ECParameterSpec ecParams)
    throws GeneralSecurityException {
  EllipticCurve ec = ecParams.getCurve();
  ECField field = ec.getField();
  if (!(field instanceof ECFieldFp)) {
    throw new GeneralSecurityException("Only curves over prime order fields are supported");
  }
  BigInteger p = ((java.security.spec.ECFieldFp) field).getP();
  if (x.compareTo(BigInteger.ZERO) == -1 || x.compareTo(p) != -1) {
    throw new GeneralSecurityException("x is out of range");
  }
  // Compute rhs == x^3 + a x + b (mod p)
  BigInteger rhs = x.multiply(x).add(ec.getA()).multiply(x).add(ec.getB()).mod(p);
  BigInteger y = modSqrt(rhs, p);
  if (bit0 != y.testBit(0)) {
    y = p.subtract(y).mod(p);
  }
  return new ECPoint(x, y);
}

Source File: DOMKeyValue.java From jdk8u_jdk with GNU General Public License v2.0

6 votes

private static ECPoint decodePoint(byte[] data, EllipticCurve curve)
        throws IOException {
    if ((data.length == 0) || (data[0] != 4)) {
        throw new IOException("Only uncompressed point format " +
                              "supported");
    }
    // Per ANSI X9.62, an encoded point is a 1 byte type followed by
    // ceiling(log base 2 field-size / 8) bytes of x and the same of y.
    int n = (data.length - 1) / 2;
    if (n != ((curve.getField().getFieldSize() + 7) >> 3)) {
        throw new IOException("Point does not match field size");
    }

    byte[] xb = Arrays.copyOfRange(data, 1, 1 + n);
    byte[] yb = Arrays.copyOfRange(data, n + 1, n + 1 + n);

    return new ECPoint(new BigInteger(1, xb), new BigInteger(1, yb));
}

Source File: ECOperations.java From jdk8u_jdk with GNU General Public License v2.0

6 votes

public static Optional<ECOperations> forParameters(ECParameterSpec params) {

        EllipticCurve curve = params.getCurve();
        if (!(curve.getField() instanceof ECFieldFp)) {
            return Optional.empty();
        }
        ECFieldFp primeField = (ECFieldFp) curve.getField();

        BigInteger three = BigInteger.valueOf(3);
        if (!primeField.getP().subtract(curve.getA()).equals(three)) {
            return Optional.empty();
        }
        IntegerFieldModuloP field = fields.get(primeField.getP());
        if (field == null) {
            return Optional.empty();
        }

        IntegerFieldModuloP orderField = orderFields.get(params.getOrder());
        if (orderField == null) {
            return Optional.empty();
        }

        ImmutableIntegerModuloP b = field.getElement(curve.getB());
        ECOperations ecOps = new ECOperations(b, orderField);
        return Optional.of(ecOps);
    }

Source File: BCDSTU4145PublicKey.java From ripple-lib-java with ISC License

6 votes

public BCDSTU4145PublicKey(
    org.ripple.bouncycastle.jce.spec.ECPublicKeySpec spec)
{
    this.q = spec.getQ();

    if (spec.getParams() != null) // can be null if implictlyCa
    {
        ECCurve curve = spec.getParams().getCurve();
        EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, spec.getParams().getSeed());

        this.ecSpec = EC5Util.convertSpec(ellipticCurve, spec.getParams());
    }
    else
    {
        if (q.getCurve() == null)
        {
            org.ripple.bouncycastle.jce.spec.ECParameterSpec s = BouncyCastleProvider.CONFIGURATION.getEcImplicitlyCa();

            q = s.getCurve().createPoint(q.getAffineXCoord().toBigInteger(), q.getAffineYCoord().toBigInteger());
        }
        this.ecSpec = null;
    }
}

Source File: ECPointUtil.java From ripple-lib-java with ISC License

5 votes

/**
 * Decode a point on this curve which has been encoded using point
 * compression (X9.62 s 4.2.1 and 4.2.2) or regular encoding.
 * 
 * @param curve
 *            The elliptic curve.
 * @param encoded
 *            The encoded point.
 * @return the decoded point.
 */
public static ECPoint decodePoint(
   EllipticCurve curve, 
   byte[] encoded)
{
    ECCurve c = null;
    
    if (curve.getField() instanceof ECFieldFp)
    {
        c = new ECCurve.Fp(
                ((ECFieldFp)curve.getField()).getP(), curve.getA(), curve.getB());
    }
    else
    {
        int k[] = ((ECFieldF2m)curve.getField()).getMidTermsOfReductionPolynomial();
        
        if (k.length == 3)
        {
            c = new ECCurve.F2m(
                    ((ECFieldF2m)curve.getField()).getM(), k[2], k[1], k[0], curve.getA(), curve.getB());
        }
        else
        {
            c = new ECCurve.F2m(
                    ((ECFieldF2m)curve.getField()).getM(), k[0], curve.getA(), curve.getB());
        }
    }
    
    org.ripple.bouncycastle.math.ec.ECPoint p = c.decodePoint(encoded);

    return new ECPoint(p.getAffineXCoord().toBigInteger(), p.getAffineYCoord().toBigInteger());
}

Source File: BCECGOST3410PrivateKey.java From ripple-lib-java with ISC License

5 votes

public BCECGOST3410PrivateKey(
    String algorithm,
    ECPrivateKeyParameters params,
    BCECGOST3410PublicKey pubKey,
    ECParameterSpec spec)
{
    ECDomainParameters dp = params.getParameters();

    this.algorithm = algorithm;
    this.d = params.getD();

    if (spec == null)
    {
        EllipticCurve ellipticCurve = EC5Util.convertCurve(dp.getCurve(), dp.getSeed());

        this.ecSpec = new ECParameterSpec(
            ellipticCurve,
            new ECPoint(
                dp.getG().getAffineXCoord().toBigInteger(),
                dp.getG().getAffineYCoord().toBigInteger()),
            dp.getN(),
            dp.getH().intValue());
    }
    else
    {
        this.ecSpec = spec;
    }

    this.gostParams = pubKey.getGostParams();

    publicKey = getPublicKeyDetails(pubKey);
}

java.security.spec.EllipticCurve Java Examples