org.spongycastle.asn1.ASN1Integer Java Examples

public static boolean verify(byte[] publicKey, byte[] signature, byte[] msg) {
    X9ECParameters params = SECNamedCurves.getByName("secp256k1");
    ECDomainParameters EC_PARAMS = new ECDomainParameters(params.getCurve(), params.getG(), params.getN(), params.getH());
    synchronized (EC_PARAMS) {
        boolean valid;
        ECDSASigner signerVer = new ECDSASigner(new HMacDSAKCalculator(new SHA256Digest()));
        try {
            ECPublicKeyParameters pubKey = new ECPublicKeyParameters(EC_PARAMS.getCurve().decodePoint(publicKey), EC_PARAMS);
            signerVer.init(false, pubKey);
            ASN1InputStream derSigStream = new ASN1InputStream(signature);
            DLSequence seq = (DLSequence) derSigStream.readObject();
            BigInteger r = ((ASN1Integer) seq.getObjectAt(0)).getPositiveValue();
            BigInteger s = ((ASN1Integer) seq.getObjectAt(1)).getPositiveValue();
            derSigStream.close();
            valid = signerVer.verifySignature(msg, r, s);
        } catch (IOException e) {
            throw new RuntimeException();
        }
        return valid;
    }
}
 

static PublicKey buildPublicKey(byte[] rawBytes) throws CryptoException {
    try {
        ASN1InputStream bIn = new ASN1InputStream(new ByteArrayInputStream(rawBytes));
        SubjectPublicKeyInfo info = SubjectPublicKeyInfo
                .getInstance(new ASN1InputStream(bIn.readObject().getEncoded()).readObject());
        DLSequence dlSequence = (DLSequence) ASN1Primitive.fromByteArray(info.getPublicKeyData().getBytes());
        BigInteger modulus = ((ASN1Integer) dlSequence.getObjectAt(0)).getPositiveValue();
        BigInteger exponent = ((ASN1Integer) dlSequence.getObjectAt(1)).getPositiveValue();

        RSAPublicKeySpec spec = new RSAPublicKeySpec(modulus, exponent);
        KeyFactory kf = getRSAKeyFactory();
        return kf.generatePublic(spec);
    } catch (InvalidKeySpecException | IOException e) {
        throw new CryptoException(e);
    }
}
 

static PublicKey buildPublicKey(byte[] rawBytes) throws CryptoException {
    try {
        //FIXME replacing X509EncodedKeySpec because of problem with 8.1
        //Since 8.1 Bouncycastle cryptography was replaced with implementation from Conscrypt
        //https://developer.android.com/about/versions/oreo/android-8.1.html
        //either it's a bug in Conscrypt, our public key DER structure or use of X509EncodedKeySpec changed
        //alternative needed as this adds expensive Spongycastle dependence
        ASN1InputStream bIn = new ASN1InputStream(new ByteArrayInputStream(rawBytes));
        SubjectPublicKeyInfo info = SubjectPublicKeyInfo
                .getInstance(new ASN1InputStream(bIn.readObject().getEncoded()).readObject());
        DLSequence dlSequence = (DLSequence) ASN1Primitive.fromByteArray(info.getPublicKeyData().getBytes());
        BigInteger modulus = ((ASN1Integer) dlSequence.getObjectAt(0)).getPositiveValue();
        BigInteger exponent = ((ASN1Integer) dlSequence.getObjectAt(1)).getPositiveValue();

        RSAPublicKeySpec spec = new RSAPublicKeySpec(modulus, exponent);
        KeyFactory kf = getRSAKeyFactory();
        return kf.generatePublic(spec);
    } catch (InvalidKeySpecException | IOException e) {
        throw new CryptoException(e);
    }
}
 

/**
 * Output this ECKey as an ASN.1 encoded private key, as understood by OpenSSL or used by the BitCoin reference
 * implementation in its wallet storage format.
 */
public byte[] toASN1() {
    try {
        ByteArrayOutputStream baos = new ByteArrayOutputStream(400);

        // ASN1_SEQUENCE(EC_PRIVATEKEY) = {
        //   ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
        //   ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
        //   ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
        //   ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
        // } ASN1_SEQUENCE_END(EC_PRIVATEKEY)
        DERSequenceGenerator seq = new DERSequenceGenerator(baos);
        seq.addObject(new ASN1Integer(1)); // version
        seq.addObject(new DEROctetString(priv.toByteArray()));
        seq.addObject(new DERTaggedObject(0, SECNamedCurves.getByName("secp256k1").toASN1Primitive()));
        seq.addObject(new DERTaggedObject(1, new DERBitString(getPubKey())));
        seq.close();
        return baos.toByteArray();
    } catch (IOException e) {
        throw new RuntimeException(e);  // Cannot happen, writing to memory stream.
    }
}
 

private static BigInteger extractPrivateKeyFromASN1(byte[] asn1privkey) {
    // To understand this code, see the definition of the ASN.1 format for EC private keys in the OpenSSL source
    // code in ec_asn1.c:
    //
    // ASN1_SEQUENCE(EC_PRIVATEKEY) = {
    //   ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
    //   ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
    //   ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
    //   ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
    // } ASN1_SEQUENCE_END(EC_PRIVATEKEY)
    //
    try {
        ASN1InputStream decoder = new ASN1InputStream(asn1privkey);
        DLSequence seq = (DLSequence) decoder.readObject();
        checkArgument(seq.size() == 4, "Input does not appear to be an ASN.1 OpenSSL EC private key");
        checkArgument(((ASN1Integer) seq.getObjectAt(0)).getValue().equals(BigInteger.ONE),
                "Input is of wrong version");
        Object obj = seq.getObjectAt(1);
        byte[] bits = ((ASN1OctetString) obj).getOctets();
        decoder.close();
        return new BigInteger(1, bits);
    } catch (IOException e) {
        throw new RuntimeException(e);  // Cannot happen, reading from memory stream.
    }
}
 

private static ByteArrayOutputStream derByteStream(BigInteger r,BigInteger s) throws IOException {
    // Usually 70-72 bytes.
    ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
    DERSequenceGenerator seq = new DERSequenceGenerator(bos);
    seq.addObject(new ASN1Integer(r));
    seq.addObject(new ASN1Integer(s));
    seq.close();
    return bos;
}
 

private byte[] getInputSignature(Tx_in input) throws ZCashException {
  byte[] personalization = Bytes.concat(ZCASH_SIGNATURE_HASH_PERSONALIZATION, Utils.int32BytesLE(consensusBranchId));
  Blake2bDigest tx_digest = new Blake2bDigest(null, 32, null, personalization);
  byte[] preimage = Bytes.concat(
    tx_sig_bytes,
    input.txid,
    Utils.int32BytesLE(input.index),
    Utils.compactSizeIntLE(input.script.length),
    input.script,
    Utils.int64BytesLE(input.value),
    Utils.int32BytesLE(input.sequence)
  );

  byte[] hash = new byte[32];
  tx_digest.update(preimage, 0, preimage.length);
  tx_digest.doFinal(hash, 0);
  Sha256Hash sha256Hash = new Sha256Hash(hash);
  ECKey.ECDSASignature sig = privKey.sign(sha256Hash);
  sig = sig.toCanonicalised();
  ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
  try {
    DERSequenceGenerator seq = new DERSequenceGenerator(bos);
    seq.addObject(new ASN1Integer(sig.r));
    seq.addObject(new ASN1Integer(sig.s));
    seq.close();
  } catch (IOException e) {
    throw new ZCashException("Cannot encode signature into transaction in ZCashTransaction_taddr.getInputSignature", e);
  }

  return bos.toByteArray();
}
 

private byte[] getInputSignature(Tx_in input) throws ZCashException {
  byte[] personalization = Bytes.concat(ZCASH_SIGNATURE_HASH_PERSONALIZATION, Utils.int32BytesLE(consensusBranchId));
  Blake2bDigest tx_digest = new Blake2bDigest(null, 32, null, personalization);
  byte[] preimage = Bytes.concat(
    tx_sig_bytes,
    input.txid,
    Utils.int32BytesLE(input.index),
    Utils.compactSizeIntLE(input.script.length),
    input.script,
    Utils.int64BytesLE(input.value),
    Utils.int32BytesLE(input.sequence)
  );

  byte[] hash = new byte[32];
  tx_digest.update(preimage, 0, preimage.length);
  tx_digest.doFinal(hash, 0);
  Sha256Hash sha256Hash = new Sha256Hash(hash);
  ECKey.ECDSASignature sig = privKey.sign(sha256Hash);
  sig = sig.toCanonicalised();
  ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
  try {
    DERSequenceGenerator seq = new DERSequenceGenerator(bos);
    seq.addObject(new ASN1Integer(sig.r));
    seq.addObject(new ASN1Integer(sig.s));
    seq.close();
  } catch (IOException e) {
    throw new ZCashException("Cannot encode signature into transaction in ZCashTransaction_taddr.getInputSignature", e);
  }

  return bos.toByteArray();
}
 

protected ByteArrayOutputStream derByteStream() throws IOException {
    // Usually 70-72 bytes.
    ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
    DERSequenceGenerator seq = new DERSequenceGenerator(bos);
    seq.addObject(new ASN1Integer(r));
    seq.addObject(new ASN1Integer(s));
    seq.close();
    return bos;
}
 

protected ByteArrayOutputStream derByteStream() throws IOException {
    // Usually 70-72 bytes.
    ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
    DERSequenceGenerator seq = new DERSequenceGenerator(bos);
    seq.addObject(new ASN1Integer(r));
    seq.addObject(new ASN1Integer(s));
    seq.close();
    return bos;
}
 

/**
 	 * DER - From Big Integer rs to byte[]
 	 * UAF_ALG_SIGN_SECP256K1_ECDSA_SHA256_DER 0x06
 	 * DER [ITU-X690-2008] encoded ECDSA signature [RFC5480] on the secp256k1 curve.
 	 * I.e. a DER encoded SEQUENCE { r INTEGER, s INTEGER }
 	 * @param signature
 	 * @return
 	 * @throws IOException
 	 */
 	public static byte[] getEncoded(BigInteger[] sigs)
		throws IOException {
	ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
	DERSequenceGenerator seq = new DERSequenceGenerator(bos);
	seq.addObject(new ASN1Integer(sigs[0]));
	seq.addObject(new ASN1Integer(sigs[1]));
	seq.close();
	return bos.toByteArray();
}
 

/**
 	 * DER - From byte[] to Big Integer rs
 	 * UAF_ALG_SIGN_SECP256K1_ECDSA_SHA256_DER 0x06
 	 * DER [ITU-X690-2008] encoded ECDSA signature [RFC5480] on the secp256k1 curve.
 	 * I.e. a DER encoded SEQUENCE { r INTEGER, s INTEGER }
 	 * @param signature
 	 * @return
 	 * @throws IOException
 	 */
public static BigInteger[] decodeToBigIntegerArray(byte[] signature) throws IOException {
	ASN1InputStream decoder = new ASN1InputStream(signature);
	DLSequence seq = (DLSequence) decoder.readObject();
	ASN1Integer r = (ASN1Integer) seq.getObjectAt(0);
	ASN1Integer s = (ASN1Integer) seq.getObjectAt(1);
	decoder.close();
	BigInteger[] ret = new BigInteger[2];
	ret[0] = r.getPositiveValue();
	ret[1] = s.getPositiveValue();
	return ret;
}
 

protected ByteArrayOutputStream derByteStream() throws IOException {
    // Usually 70-72 bytes.
    ByteArrayOutputStream bos = new ByteArrayOutputStream(72);
    DERSequenceGenerator seq = new DERSequenceGenerator(bos);
    seq.addObject(new ASN1Integer(r));
    seq.addObject(new ASN1Integer(s));
    seq.close();
    return bos;
}