Examples with ECPoint org.bouncycastle.math.ec.ECPoint used on opensource projects

Example 1 with ECPoint

use of org.bouncycastle.math.ec.ECPoint in project robovm by robovm.

the class ECDHBasicAgreement method calculateAgreement.

public BigInteger calculateAgreement(CipherParameters pubKey) {
    ECPublicKeyParameters pub = (ECPublicKeyParameters) pubKey;
    ECPoint P = pub.getQ().multiply(key.getD());
    return P.getX().toBigInteger();
}

Example 2 with ECPoint

use of org.bouncycastle.math.ec.ECPoint in project robovm by robovm.

the class ECKeyPairGenerator method generateKeyPair.

/**
     * Given the domain parameters this routine generates an EC key
     * pair in accordance with X9.62 section 5.2.1 pages 26, 27.
     */
public AsymmetricCipherKeyPair generateKeyPair() {
    BigInteger n = params.getN();
    int nBitLength = n.bitLength();
    BigInteger d;
    do {
        d = new BigInteger(nBitLength, random);
    } while (d.equals(ZERO) || (d.compareTo(n) >= 0));
    ECPoint Q = params.getG().multiply(d);
    return new AsymmetricCipherKeyPair(new ECPublicKeyParameters(Q, params), new ECPrivateKeyParameters(d, params));
}

Example 3 with ECPoint

use of org.bouncycastle.math.ec.ECPoint in project robovm by robovm.

the class ECDSASigner method generateSignature.

// 5.3 pg 28
/**
     * generate a signature for the given message using the key we were
     * initialised with. For conventional DSA the message should be a SHA-1
     * hash of the message of interest.
     *
     * @param message the message that will be verified later.
     */
public BigInteger[] generateSignature(byte[] message) {
    BigInteger n = key.getParameters().getN();
    BigInteger e = calculateE(n, message);
    BigInteger r = null;
    BigInteger s = null;
    // 5.3.2
    do // generate s
    {
        BigInteger k = null;
        int nBitLength = n.bitLength();
        do // generate r
        {
            do {
                k = new BigInteger(nBitLength, random);
            } while (k.equals(ZERO) || k.compareTo(n) >= 0);
            ECPoint p = key.getParameters().getG().multiply(k);
            // 5.3.3
            BigInteger x = p.getX().toBigInteger();
            r = x.mod(n);
        } while (r.equals(ZERO));
        BigInteger d = ((ECPrivateKeyParameters) key).getD();
        s = k.modInverse(n).multiply(e.add(d.multiply(r))).mod(n);
    } while (s.equals(ZERO));
    BigInteger[] res = new BigInteger[2];
    res[0] = r;
    res[1] = s;
    return res;
}

Example 4 with ECPoint

use of org.bouncycastle.math.ec.ECPoint in project robovm by robovm.

the class ECDSASigner method verifySignature.

// 5.4 pg 29
/**
     * return true if the value r and s represent a DSA signature for
     * the passed in message (for standard DSA the message should be
     * a SHA-1 hash of the real message to be verified).
     */
public boolean verifySignature(byte[] message, BigInteger r, BigInteger s) {
    BigInteger n = key.getParameters().getN();
    BigInteger e = calculateE(n, message);
    // r in the range [1,n-1]
    if (r.compareTo(ONE) < 0 || r.compareTo(n) >= 0) {
        return false;
    }
    // s in the range [1,n-1]
    if (s.compareTo(ONE) < 0 || s.compareTo(n) >= 0) {
        return false;
    }
    BigInteger c = s.modInverse(n);
    BigInteger u1 = e.multiply(c).mod(n);
    BigInteger u2 = r.multiply(c).mod(n);
    ECPoint G = key.getParameters().getG();
    ECPoint Q = ((ECPublicKeyParameters) key).getQ();
    ECPoint point = ECAlgorithms.sumOfTwoMultiplies(G, u1, Q, u2);
    // components must be bogus.
    if (point.isInfinity()) {
        return false;
    }
    BigInteger v = point.getX().toBigInteger().mod(n);
    return v.equals(r);
}

Example 5 with ECPoint

use of org.bouncycastle.math.ec.ECPoint in project XobotOS by xamarin.

the class ECDSASigner method generateSignature.

// 5.3 pg 28
/**
     * generate a signature for the given message using the key we were
     * initialised with. For conventional DSA the message should be a SHA-1
     * hash of the message of interest.
     *
     * @param message the message that will be verified later.
     */
public BigInteger[] generateSignature(byte[] message) {
    BigInteger n = key.getParameters().getN();
    BigInteger e = calculateE(n, message);
    BigInteger r = null;
    BigInteger s = null;
    // 5.3.2
    do // generate s
    {
        BigInteger k = null;
        int nBitLength = n.bitLength();
        do // generate r
        {
            do {
                k = new BigInteger(nBitLength, random);
            } while (k.equals(ZERO) || k.compareTo(n) >= 0);
            ECPoint p = key.getParameters().getG().multiply(k);
            // 5.3.3
            BigInteger x = p.getX().toBigInteger();
            r = x.mod(n);
        } while (r.equals(ZERO));
        BigInteger d = ((ECPrivateKeyParameters) key).getD();
        s = k.modInverse(n).multiply(e.add(d.multiply(r))).mod(n);
    } while (s.equals(ZERO));
    BigInteger[] res = new BigInteger[2];
    res[0] = r;
    res[1] = s;
    return res;
}