Java BigIntegers.fromUnsignedByteArray方法代码示例

import org.bouncycastle.util.BigIntegers; //导入方法依赖的package包/类
@Deprecated
public static ECPoint decodeFPPoint(ECCurve curve, byte[] data) {
    // Patched org.bouncycastle.math.ec.ECCurve#decodePoint code.
    int expectedLength = (curve.getFieldSize() + 7) / 8;
    if (expectedLength != data.length) {
        throw new IllegalArgumentException("incorrect data length for compact encoding");
    }

    BigInteger X = BigIntegers.fromUnsignedByteArray(data, 0, expectedLength);
    ECPoint p = decompressFPPoint(curve, X);

    if (!satisfiesCofactor(curve, p)) {
        throw new IllegalArgumentException("invalid point");
    }

    return p;
}
 

import org.bouncycastle.util.BigIntegers; //导入方法依赖的package包/类
@Override
public Optional<ECPublicKey> importKey(String curveName, byte[] data) {
    int fieldLength = ECAssistant.fieldLength(curveName);
    if (fieldLength(data.length) != fieldLength) {
        logger.warn("-- importKey() - bad data length: {} curve: {} data:0x{}",
                data.length, curveName, Hex.toHexString(data));
    }

    if (!checkType(data[0])) {
        logger.warn("-- importKey() - bad data type: 0x{}", Integer.toHexString(data[0]));
    }

    BigInteger x = BigIntegers.fromUnsignedByteArray(data, 1, fieldLength);
    BigInteger y = BigIntegers.fromUnsignedByteArray(data, 1 + fieldLength, fieldLength);

    return ECKeyFactories.publicKeyFactory()
            .createECPublicKey(x, y, curveName);
}
 

import org.bouncycastle.util.BigIntegers; //导入方法依赖的package包/类
@Override
public Optional<ECPrivateKey> importKey(String curveName, byte[] data) {
    X9ECParameters x9ECParameters = ECAssistant.x9ECParameters(curveName);
    int fieldLength = ECAssistant.fieldLength(x9ECParameters);
    if (fieldLength(data.length) != fieldLength) {
        logger.warn("-- importKey() - bad data length: {} curve: {} data:0x{}",
                data.length, curveName, Hex.toHexString(data));
    }


    BigInteger x = BigIntegers.fromUnsignedByteArray(data, 0, fieldLength);
    BigInteger y = ECPointsCompact.y(x9ECParameters.getCurve(), x);
    BigInteger d = BigIntegers.fromUnsignedByteArray(data, fieldLength, fieldLength);

    return ECKeyFactories.privateKeyFactory()
            .createECPrivateKey(x, y, d, curveName);
}
 

import org.bouncycastle.util.BigIntegers; //导入方法依赖的package包/类
@Override
public Optional<ECPublicKey> importKey(String curveName, byte[] data) {
    X9ECParameters x9ECParameters = ECAssistant.x9ECParameters(curveName);
    int fieldLength = ECAssistant.fieldLength(x9ECParameters);
    if (fieldLength(data.length) != fieldLength) {
        logger.warn("-- importKey() - bad data length: {} curve: {} data:0x{}",
                data.length, curveName, Hex.toHexString(data));
    }

    BigInteger x = BigIntegers.fromUnsignedByteArray(data);
    BigInteger y = ECPointsCompact.y(x9ECParameters.getCurve(), x);

    return ECKeyFactories.publicKeyFactory()
            .createECPublicKey(x, y, curveName);
}
 

import org.bouncycastle.util.BigIntegers; //导入方法依赖的package包/类
@Override
public Optional<ECPrivateKey> importKey(String curveName, byte[] data) {
    int fieldLength = ECAssistant.fieldLength(curveName);
    if (fieldLength(data.length) != fieldLength) {
        logger.warn("-- importKey() - bad data length: {} curve: {} data:0x{}",
                data.length, curveName, Hex.toHexString(data));
    }

    BigInteger d = BigIntegers.fromUnsignedByteArray(data, 0, fieldLength);

    return ECKeyFactories.privateKeyFactory()
            .createECPrivateKey(d, curveName);
}
 

import org.bouncycastle.util.BigIntegers; //导入方法依赖的package包/类
/**
    * We encode the message using a probabilistic algorithm.
    *
    * @param msg The message to be encoded
    * @param rand
    * @return
    * @throws UnsupportedOperationException
    */
@Override
public ECPoint injectiveEncode(byte[] msg, Random rand) throws UnsupportedOperationException {

       final int BLOCK_LEN = getInjectiveEncodeMsgLength();
       ECCurve curve = curveParams.getCurve();
       if (!(curve instanceof ECCurve.AbstractFp)) {
           throw new UnsupportedOperationException("We currently only support prime fields for message encoding");
       }
       ECCurve.AbstractFp curveFp = (ECCurve.AbstractFp) curve;

       if (msg.length != BLOCK_LEN) {
           if (msg.length > BLOCK_LEN)
               logger.warn("Message larger than maximum length ({} bytes, field size is {} bytes), truncating", msg.length,
                       BLOCK_LEN);
           byte[] tmp = new byte[BLOCK_LEN];
           System.arraycopy(msg, 0, tmp, 0, Math.min(tmp.length, msg.length));
           msg = tmp;
       }

	// For now we use a probabilistic method.
       ECFieldElement A = curveFp.getA();
       ECFieldElement B = curveFp.getB();
       BigInteger M = BigIntegers.fromUnsignedByteArray(msg);

       ECFieldElement y = null;
	ECFieldElement x = null;
	byte[] randBytes = new byte[NONCE_LENGTH];
       for (int j = 0; j < (1 << LOG_LOG_ENCODING_ERROR_RATE); ++j) {
		rand.nextBytes(randBytes);
		x = curveFp.fromBigInteger(
				BigIntegers.fromUnsignedByteArray(randBytes)
				.shiftLeft(BLOCK_LEN * 8).or(M));

           ECFieldElement z = x.square().multiplyPlusProduct(x,A,x).add(B);
           y = z.sqrt();
           if (y != null)
               break;
       }
       if (y == null) {
           logger.error("Miracle! Didn't find mapping for msg -- occurs with prob 2^{-{}}", 1<< LOG_LOG_ENCODING_ERROR_RATE);
           return null;
       }
       return curveFp.createPoint(x.toBigInteger(), y.toBigInteger());
}