Java ECAlgorithms.isFpCurve方法代码示例

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
public static byte[] serializeECPoint(short[] ecPointFormats, ECPoint point) throws IOException
{
    ECCurve curve = point.getCurve();

    /*
     * RFC 4492 5.7. ...an elliptic curve point in uncompressed or compressed format. Here, the
     * format MUST conform to what the server has requested through a Supported Point Formats
     * Extension if this extension was used, and MUST be uncompressed if this extension was not
     * used.
     */
    boolean compressed = false;
    if (ECAlgorithms.isFpCurve(curve))
    {
        compressed = isCompressionPreferred(ecPointFormats, ECPointFormat.ansiX962_compressed_prime);
    }
    else if (ECAlgorithms.isF2mCurve(curve))
    {
        compressed = isCompressionPreferred(ecPointFormats, ECPointFormat.ansiX962_compressed_char2);
    }
    return point.getEncoded(compressed);
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
public static void discoverEndomorphisms(X9ECParameters x9)
{
    if (x9 == null)
    {
        throw new NullPointerException("x9");
    }

    ECCurve c = x9.getCurve();
    if (ECAlgorithms.isFpCurve(c))
    {
        BigInteger characteristic = c.getField().getCharacteristic();

        if (c.getA().isZero() && characteristic.mod(ECConstants.THREE).equals(ECConstants.ONE))
        {
            System.out.println("Curve has a 'GLV Type B' endomorphism with these parameters:");
            printGLVTypeBParameters(x9);
        }
    }
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
private static void discoverEndomorphism(String curveName)
{
    X9ECParameters x9 = ECNamedCurveTable.getByName(curveName);
    if (x9 == null)
    {
        System.err.println("Unknown curve: " + curveName);
        return;
    }

    ECCurve c = x9.getCurve();
    if (ECAlgorithms.isFpCurve(c))
    {
        BigInteger characteristic = c.getField().getCharacteristic();

        if (c.getA().isZero() && characteristic.mod(ECConstants.THREE).equals(ECConstants.ONE))
        {
            System.out.println("Curve '" + curveName + "' has a 'GLV Type B' endomorphism with these parameters: ");
            printGLVTypeBParameters(x9);
        }
    }
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
private void setFieldIdentifier()
{
    if (ECAlgorithms.isFpCurve(curve))
    {
        fieldIdentifier = prime_field;
    }
    else if (ECAlgorithms.isF2mCurve(curve))
    {
        fieldIdentifier = characteristic_two_field;
    }
    else
    {
        throw new IllegalArgumentException("This type of ECCurve is not implemented");
    }
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
public X9ECParameters(
    ECCurve     curve,
    X9ECPoint   g,
    BigInteger  n,
    BigInteger  h,
    byte[]      seed)
{
    this.curve = curve;
    this.g = g;
    this.n = n;
    this.h = h;
    this.seed = seed;

    if (ECAlgorithms.isFpCurve(curve))
    {
        this.fieldID = new X9FieldID(curve.getField().getCharacteristic());
    }
    else if (ECAlgorithms.isF2mCurve(curve))
    {
        PolynomialExtensionField field = (PolynomialExtensionField)curve.getField();
        int[] exponents = field.getMinimalPolynomial().getExponentsPresent();
        if (exponents.length == 3)
        {
            this.fieldID = new X9FieldID(exponents[2], exponents[1]);
        }
        else if (exponents.length == 5)
        {
            this.fieldID = new X9FieldID(exponents[4], exponents[1], exponents[2], exponents[3]);
        }
        else
        {
            throw new IllegalArgumentException("Only trinomial and pentomial curves are supported");
        }
    }
    else
    {
        throw new IllegalArgumentException("'curve' is of an unsupported type");
    }
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
public X9ECParameters(
    ECCurve     curve,
    ECPoint     g,
    BigInteger  n,
    BigInteger  h,
    byte[]      seed)
{
    this.curve = curve;
    this.g = g.normalize();
    this.n = n;
    this.h = h;
    this.seed = seed;

    if (ECAlgorithms.isFpCurve(curve))
    {
        this.fieldID = new X9FieldID(curve.getField().getCharacteristic());
    }
    else if (ECAlgorithms.isF2mCurve(curve))
    {
        PolynomialExtensionField field = (PolynomialExtensionField)curve.getField();
        int[] exponents = field.getMinimalPolynomial().getExponentsPresent();
        if (exponents.length == 3)
        {
            this.fieldID = new X9FieldID(exponents[2], exponents[1]);
        }
        else if (exponents.length == 5)
        {
            this.fieldID = new X9FieldID(exponents[4], exponents[1], exponents[2], exponents[3]);
        }
        else
        {
            throw new IllegalArgumentException("Only trinomial and pentomial curves are supported");
        }
    }
    else
    {
        throw new IllegalArgumentException("'curve' is of an unsupported type");
    }
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
public static ECPoint deserializeECPoint(short[] ecPointFormats, ECCurve curve, byte[] encoding) throws IOException
{
    if (encoding == null || encoding.length < 1)
    {
        throw new TlsFatalAlert(AlertDescription.illegal_parameter);
    }

    short actualFormat;
    switch (encoding[0])
    {
    case 0x02: // compressed
    case 0x03: // compressed
    {
        if (ECAlgorithms.isF2mCurve(curve))
        {
            actualFormat = ECPointFormat.ansiX962_compressed_char2;
        }
        else if (ECAlgorithms.isFpCurve(curve))
        {
            actualFormat = ECPointFormat.ansiX962_compressed_prime;
        }
        else
        {
            throw new TlsFatalAlert(AlertDescription.illegal_parameter);
        }
        break;
    }
    case 0x04: // uncompressed
    {
        actualFormat = ECPointFormat.uncompressed;
        break;
    }
    case 0x00: // infinity
    case 0x06: // hybrid
    case 0x07: // hybrid
    default:
        throw new TlsFatalAlert(AlertDescription.illegal_parameter);
    }

    if (actualFormat != ECPointFormat.uncompressed
        && (ecPointFormats == null || !Arrays.contains(ecPointFormats, actualFormat)))
    {
        throw new TlsFatalAlert(AlertDescription.illegal_parameter);
    }

    return curve.decodePoint(encoding);
}
 

import org.bouncycastle.math.ec.ECAlgorithms; //导入方法依赖的package包/类
public static void writeExplicitECParameters(short[] ecPointFormats, ECDomainParameters ecParameters,
    OutputStream output) throws IOException
{
    ECCurve curve = ecParameters.getCurve();

    if (ECAlgorithms.isFpCurve(curve))
    {
        TlsUtils.writeUint8(ECCurveType.explicit_prime, output);

        writeECParameter(curve.getField().getCharacteristic(), output);
    }
    else if (ECAlgorithms.isF2mCurve(curve))
    {
        PolynomialExtensionField field = (PolynomialExtensionField)curve.getField();
        int[] exponents = field.getMinimalPolynomial().getExponentsPresent();

        TlsUtils.writeUint8(ECCurveType.explicit_char2, output);

        int m = exponents[exponents.length - 1];
        TlsUtils.checkUint16(m);
        TlsUtils.writeUint16(m, output);

        if (exponents.length == 3)
        {
            TlsUtils.writeUint8(ECBasisType.ec_basis_trinomial, output);
            writeECExponent(exponents[1], output);
        }
        else if (exponents.length == 5)
        {
            TlsUtils.writeUint8(ECBasisType.ec_basis_pentanomial, output);
            writeECExponent(exponents[1], output);
            writeECExponent(exponents[2], output);
            writeECExponent(exponents[3], output);
        }
        else
        {
            throw new IllegalArgumentException("Only trinomial and pentomial curves are supported");
        }
    }
    else
    {
        throw new IllegalArgumentException("'ecParameters' not a known curve type");
    }

    writeECFieldElement(curve.getA(), output);
    writeECFieldElement(curve.getB(), output);
    TlsUtils.writeOpaque8(serializeECPoint(ecPointFormats, ecParameters.getG()), output);
    writeECParameter(ecParameters.getN(), output);
    writeECParameter(ecParameters.getH(), output);
}