org.bouncycastle.asn1.x9.X9IntegerConverter Java Examples

/**
 * * Copyright 2011 Google Inc. * Copyright 2014 Andreas Schildbach * Copyright 2014-2016 the
 * libsecp256k1 contributors * * Licensed under the Apache License, Version 2.0 (the "License");
 * * you may not use this file except in compliance with the License. * You may obtain a copy of
 * the License at * *    http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by
 * applicable law or agreed to in writing, software * distributed under the License is
 * distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. * See the License for the specific language governing permissions and *
 * limitations under the License.
 * <p>
 * The method was modified to match what we need
 * <p>
 * Decompress a compressed public key (x co-ord and low-bit of y-coord).
 */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit, AlgorithmEmployed keyType) {
    ECCurve.Fp curve;

    switch (keyType) {
        case SECP256R1:
            curve = (ECCurve.Fp) ecParamsR1.getCurve();
            break;

        default:
            curve = (ECCurve.Fp) ecParamsK1.getCurve();
            break;
    }

    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(curve));
    compEnc[0] = (byte) (yBit ? COMPRESSED_PUBLIC_KEY_BYTE_INDICATOR_NEGATIVE_Y
            : COMPRESSED_PUBLIC_KEY_BYTE_INDICATOR_POSITIVE_Y);
    return curve.decodePoint(compEnc);
}
 

public static byte[] asn1derToConcatenatedRS(final byte[] derEncodedSignatureValue, int signLength) throws IOException {
    int len = signLength / 2;

    ASN1InputStream asn1InputStream = new ASN1InputStream(derEncodedSignatureValue);
    ASN1Primitive asn1Primitive = asn1InputStream.readObject();
    asn1InputStream.close();

    ASN1Sequence asn1Sequence = (ASN1Sequence.getInstance(asn1Primitive));
    ASN1Integer rASN1 = (ASN1Integer) asn1Sequence.getObjectAt(0);
    ASN1Integer sASN1 = (ASN1Integer) asn1Sequence.getObjectAt(1);
    X9IntegerConverter x9IntegerConverter = new X9IntegerConverter();
    byte[] r = x9IntegerConverter.integerToBytes(rASN1.getValue(), len);
    byte[] s = x9IntegerConverter.integerToBytes(sASN1.getValue(), len);

    byte[] concatenatedSignatureValue = new byte[signLength];
    System.arraycopy(r, 0, concatenatedSignatureValue, 0, len);
    System.arraycopy(s, 0, concatenatedSignatureValue, len, len);

    return concatenatedSignatureValue;
}
 

/** Decompress a compressed public key (x co-ord and low-bit of y-coord). */
private static ECPoint decompressKey(final BigInteger xBN, final boolean yBit) {
  final X9IntegerConverter x9 = new X9IntegerConverter();
  final byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
  compEnc[0] = (byte) (yBit ? 0x03 : 0x02);
  // TODO: Find a better way to handle an invalid point compression here.
  // Currently ECCurve#decodePoint throws an IllegalArgumentException.
  return CURVE.getCurve().decodePoint(compEnc);
}
 

/** Decompress a compressed public key (x co-ord and low-bit of y-coord). */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
    compEnc[0] = (byte)(yBit ? 0x03 : 0x02);
    return CURVE.getCurve().decodePoint(compEnc);
}
 

/** Decompress a compressed public key (x co-ord and low-bit of y-coord). */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
    compEnc[0] = (byte)(yBit ? 0x03 : 0x02);
    return CURVE.getCurve().decodePoint(compEnc);
}
 

/**
 * Decompress a compressed public key (x co-ord and low-bit of y-coord).
 */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
    compEnc[0] = (byte) (yBit ? 0x03 : 0x02);
    return CURVE.getCurve().decodePoint(compEnc);
}
 

/** Decompress a compressed public key (x co-ord and low-bit of y-coord). */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
    compEnc[0] = (byte) (yBit ? 0x03 : 0x02);
    return CURVE.getCurve().decodePoint(compEnc);
}
 

/** Decompress a compressed public key (x co-ord and low-bit of y-coord). */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
    compEnc[0] = (byte) (yBit ? 0x03 : 0x02);
    return CURVE.getCurve().decodePoint(compEnc);
}
 

/**
 * Calculates the sent address of an EthereumTransaction. Note this can be a costly operation to calculate. . This requires that you have Bouncy castle as a dependency in your project
 *
 *
 * @param eTrans transaction
 * @param chainId chain identifier (e.g. 1 main net)
 * @return sent address as byte array
 */
public static byte[] getSendAddress(EthereumTransaction eTrans, int chainId) {
	// init, maybe we move this out to save time
	X9ECParameters params = SECNamedCurves.getByName("secp256k1");
	ECDomainParameters CURVE=new ECDomainParameters(params.getCurve(), params.getG(), params.getN(), params.getH());	 // needed for getSentAddress

 
    byte[] transactionHash;

    if ((eTrans.getSig_v()[0]==chainId*2+EthereumUtil.CHAIN_ID_INC) || (eTrans.getSig_v()[0]==chainId*2+EthereumUtil.CHAIN_ID_INC+1)) {  // transaction hash with dummy signature data
    	 transactionHash = EthereumUtil.getTransactionHashWithDummySignatureEIP155(eTrans);
    } else {  // transaction hash without signature data
	 transactionHash = EthereumUtil.getTransactionHashWithoutSignature(eTrans);
    }
  // signature to address
	BigInteger bR = new BigInteger(1,eTrans.getSig_r());
	BigInteger bS = new BigInteger(1,eTrans.getSig_s());
  // calculate v for signature
	byte v =(byte) (eTrans.getSig_v()[0]);
	if (!((v == EthereumUtil.LOWER_REAL_V) || (v== (LOWER_REAL_V+1)))) {
		byte vReal = EthereumUtil.LOWER_REAL_V;
		if (((int)v%2 == 0)) {
			v = (byte) (vReal+0x01);
		} else {
			v = vReal;
		}
	}


	// the following lines are inspired from ECKey.java of EthereumJ, but adapted to the hadoopcryptoledger context
	if (v < 27 || v > 34) {
		LOG.error("Header out of Range:  "+v);
		throw new RuntimeException("Header out of range "+v);
	}
	if (v>=31) {

		v -=4;
	}
	int receiverId = v - 27;
	BigInteger n = CURVE.getN();
    BigInteger i = BigInteger.valueOf((long) receiverId / 2);
    BigInteger x = bR.add(i.multiply(n));
    ECCurve.Fp curve = (ECCurve.Fp) CURVE.getCurve();
    BigInteger prime = curve.getQ();
    if (x.compareTo(prime) >= 0) {
        return null;
     }
    // decompress Key
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(x, 1 + x9.getByteLength(CURVE.getCurve()));
    boolean yBit=(receiverId & 1) == 1;
    compEnc[0] = (byte)(yBit ? 0x03 : 0x02);
    ECPoint R =  CURVE.getCurve().decodePoint(compEnc);
    if (!R.multiply(n).isInfinity()) {
    		return null;
    }
    BigInteger e = new BigInteger(1,transactionHash);
    BigInteger eInv = BigInteger.ZERO.subtract(e).mod(n);
    BigInteger rInv = bR.modInverse(n);
    BigInteger srInv = rInv.multiply(bS).mod(n);
    BigInteger eInvrInv = rInv.multiply(eInv).mod(n);
    ECPoint.Fp q = (ECPoint.Fp) ECAlgorithms.sumOfTwoMultiplies(CURVE.getG(), eInvrInv, R, srInv);
    byte[] pubKey=q.getEncoded(false);
    // now we need to convert the public key into an ethereum send address which is the last 20 bytes of 32 byte KECCAK-256 Hash of the key.
	Keccak.Digest256 digest256 = new Keccak.Digest256();
	digest256.update(pubKey,1,pubKey.length-1);
	byte[] kcck = digest256.digest();
    return Arrays.copyOfRange(kcck,12,kcck.length);
}
 

/**
 * Decompress a compressed public key (x co-ord and low-bit of y-coord).
 *
 * @param xBN  -
 * @param yBit -
 * @return -
 */
private static ECPoint decompressKey(BigInteger xBN, boolean yBit) {
    X9IntegerConverter x9 = new X9IntegerConverter();
    byte[] compEnc = x9.integerToBytes(xBN, 1 + x9.getByteLength(CURVE.getCurve()));
    compEnc[0] = (byte) (yBit ? 0x03 : 0x02);
    return CURVE.getCurve().decodePoint(compEnc);
}