BouncyDSTUKeyPair.java
/*******************************************************************************
* GordianKnot: Security Suite
* Copyright 2012,2025 Tony Washer
*
* 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.
******************************************************************************/
package net.sourceforge.joceanus.gordianknot.impl.bc;
import net.sourceforge.joceanus.gordianknot.api.base.GordianException;
import net.sourceforge.joceanus.gordianknot.api.keypair.GordianKeyPair;
import net.sourceforge.joceanus.gordianknot.api.keypair.GordianKeyPairSpec;
import net.sourceforge.joceanus.gordianknot.api.sign.GordianSignatureSpec;
import net.sourceforge.joceanus.gordianknot.impl.bc.BouncyEllipticKeyPair.BouncyECPrivateKey;
import net.sourceforge.joceanus.gordianknot.impl.bc.BouncyEllipticKeyPair.BouncyECPublicKey;
import net.sourceforge.joceanus.gordianknot.impl.bc.BouncySignature.BouncyDSACoder;
import net.sourceforge.joceanus.gordianknot.impl.bc.BouncySignature.BouncyDigestSignature;
import net.sourceforge.joceanus.gordianknot.impl.core.base.GordianDataConverter;
import net.sourceforge.joceanus.gordianknot.impl.core.exc.GordianCryptoException;
import net.sourceforge.joceanus.gordianknot.impl.core.exc.GordianIOException;
import net.sourceforge.joceanus.gordianknot.impl.core.keypair.GordianKeyPairValidity;
import org.bouncycastle.asn1.ASN1BitString;
import org.bouncycastle.asn1.ASN1Encodable;
import org.bouncycastle.asn1.ASN1Integer;
import org.bouncycastle.asn1.ASN1ObjectIdentifier;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Primitive;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
import org.bouncycastle.asn1.sec.ECPrivateKey;
import org.bouncycastle.asn1.ua.DSTU4145NamedCurves;
import org.bouncycastle.asn1.ua.DSTU4145Params;
import org.bouncycastle.asn1.ua.DSTU4145PointEncoder;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.Digest;
import org.bouncycastle.crypto.digests.GOST3411Digest;
import org.bouncycastle.crypto.generators.DSTU4145KeyPairGenerator;
import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
import org.bouncycastle.crypto.params.ECDomainParameters;
import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
import org.bouncycastle.crypto.params.ECPublicKeyParameters;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.crypto.signers.DSTU4145Signer;
import org.bouncycastle.jcajce.provider.asymmetric.dstu.BCDSTU4145PrivateKey;
import org.bouncycastle.jcajce.provider.asymmetric.dstu.BCDSTU4145PublicKey;
import org.bouncycastle.jcajce.provider.asymmetric.util.EC5Util;
import org.bouncycastle.jce.spec.ECNamedCurveSpec;
import org.bouncycastle.math.ec.ECCurve;
import org.bouncycastle.math.ec.ECPoint;
import java.io.IOException;
import java.math.BigInteger;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
/**
* DSTU KeyPair classes.
*/
public final class BouncyDSTUKeyPair {
/**
* DSTU algorithm.
*/
private static final String ALGO = "DSTU4145";
/**
* Expanded sandBox length.
*/
private static final int EXPANDED_LEN = 128;
/**
* Private constructor.
*/
private BouncyDSTUKeyPair() {
}
/**
* BouncyCastle DSTU KeyPair generator.
*/
public static class BouncyDSTUKeyPairGenerator
extends BouncyKeyPairGenerator {
/**
* Curve.
*/
private final String theCurve;
/**
* Generator.
*/
private final ECKeyPairGenerator theGenerator;
/**
* Domain.
*/
private final ECDomainParameters theDomain;
/**
* Spec.
*/
private final ECNamedCurveSpec theSpec;
/**
* Constructor.
* @param pFactory the Security Factory
* @param pKeySpec the keySpec
* @throws GordianException on error
*/
BouncyDSTUKeyPairGenerator(final BouncyFactory pFactory,
final GordianKeyPairSpec pKeySpec) throws GordianException {
/* Initialise underlying class */
super(pFactory, pKeySpec);
/* Create the generator */
theGenerator = new DSTU4145KeyPairGenerator();
/* Determine domain */
theCurve = pKeySpec.getElliptic().getCurveName();
theDomain = DSTU4145NamedCurves.getByOID(new ASN1ObjectIdentifier(theCurve));
theSpec = new ECNamedCurveSpec(theCurve,
theDomain.getCurve(),
theDomain.getG(),
theDomain.getN(),
theDomain.getH(),
theDomain.getSeed());
/* Perform conversion */
final ECCurve myCurve = EC5Util.convertCurve(theSpec.getCurve());
final ECPoint myG = EC5Util.convertPoint(myCurve, theSpec.getGenerator());
/* Initialise the generator */
final ECKeyGenerationParameters myParams = new ECKeyGenerationParameters(
new ECDomainParameters(myCurve, myG, theSpec.getOrder(), BigInteger.valueOf(theSpec.getCofactor())), getRandom());
theGenerator.init(myParams);
}
@Override
public BouncyKeyPair generateKeyPair() {
/* Generate and return the keyPair */
final AsymmetricCipherKeyPair myPair = theGenerator.generateKeyPair();
final BouncyECPublicKey myPublic = new BouncyECPublicKey(getKeySpec(), (ECPublicKeyParameters) myPair.getPublic());
final BouncyECPrivateKey myPrivate = new BouncyECPrivateKey(getKeySpec(), (ECPrivateKeyParameters) myPair.getPrivate());
return new BouncyKeyPair(myPublic, myPrivate);
}
@Override
public PKCS8EncodedKeySpec getPKCS8Encoding(final GordianKeyPair pKeyPair) throws GordianException {
/* Check the keyPair type and keySpecs */
BouncyKeyPair.checkKeyPair(pKeyPair, getKeySpec());
/* build and return the encoding */
final BouncyECPrivateKey myPrivateKey = (BouncyECPrivateKey) getPrivateKey(pKeyPair);
final ECPrivateKeyParameters myParms = myPrivateKey.getPrivateKey();
final BouncyECPublicKey myPublicKey = (BouncyECPublicKey) getPublicKey(pKeyPair);
final ECPublicKeyParameters myPubParms = myPublicKey.getPublicKey();
final BCDSTU4145PublicKey pubKey = new BCDSTU4145PublicKey(ALGO, myPubParms, theSpec);
final BCDSTU4145PrivateKey privKey = new BCDSTU4145PrivateKey(ALGO, myParms, pubKey, theSpec);
return new PKCS8EncodedKeySpec(privKey.getEncoded());
}
@Override
public BouncyKeyPair deriveKeyPair(final X509EncodedKeySpec pPublicKey,
final PKCS8EncodedKeySpec pPrivateKey) throws GordianException {
/* Check the keySpecs */
checkKeySpec(pPrivateKey);
/* derive keyPair */
final BouncyECPublicKey myPublic = derivePublicKey(pPublicKey);
final PrivateKeyInfo myInfo = PrivateKeyInfo.getInstance(pPrivateKey.getEncoded());
final ECPrivateKeyParameters myParms = deriveFromPrivKeyInfo(myInfo);
final BouncyECPrivateKey myPrivate = new BouncyECPrivateKey(getKeySpec(), myParms);
final BouncyKeyPair myPair = new BouncyKeyPair(myPublic, myPrivate);
/* Check that we have a matching pair */
GordianKeyPairValidity.checkValidity(getFactory(), myPair);
/* Return the keyPair */
return myPair;
}
@Override
public X509EncodedKeySpec getX509Encoding(final GordianKeyPair pKeyPair) throws GordianException {
/* Check the keyPair type and keySpecs */
BouncyKeyPair.checkKeyPair(pKeyPair, getKeySpec());
/* build and return the encoding */
final BouncyECPublicKey myPublicKey = (BouncyECPublicKey) getPublicKey(pKeyPair);
final ECPublicKeyParameters myParms = myPublicKey.getPublicKey();
final BCDSTU4145PublicKey pubKey = new BCDSTU4145PublicKey(ALGO, myParms, theSpec);
return new X509EncodedKeySpec(pubKey.getEncoded());
}
@Override
public BouncyKeyPair derivePublicOnlyKeyPair(final X509EncodedKeySpec pEncodedKey) throws GordianException {
final BouncyECPublicKey myPublic = derivePublicKey(pEncodedKey);
return new BouncyKeyPair(myPublic);
}
/**
* Derive public key from encoded.
* @param pEncodedKey the encoded key
* @return the public key
* @throws GordianException on error
*/
private BouncyECPublicKey derivePublicKey(final X509EncodedKeySpec pEncodedKey) throws GordianException {
/* Check the keySpecs */
checkKeySpec(pEncodedKey);
/* derive publicKey */
final SubjectPublicKeyInfo myInfo = SubjectPublicKeyInfo.getInstance(pEncodedKey.getEncoded());
final ECPublicKeyParameters myParms = deriveFromPubKeyInfo(myInfo);
return new BouncyECPublicKey(getKeySpec(), myParms);
}
/**
* Derive Public Key parameters from SubjectPublicKeyInfo. (extracted from BouncyCastle initialiser)
* @param pKeyInfo the keyInfo
* @return the PrivateKeyParameters
* @throws GordianException on error
*/
private ECPublicKeyParameters deriveFromPubKeyInfo(final SubjectPublicKeyInfo pKeyInfo) throws GordianException {
final ASN1BitString bits = pKeyInfo.getPublicKeyData();
final ASN1OctetString key;
try {
key = (ASN1OctetString) ASN1Primitive.fromByteArray(bits.getBytes());
} catch (IOException ex) {
throw new GordianIOException("error recovering public key", ex);
}
final byte[] keyEnc = key.getOctets();
final ECCurve curve = theDomain.getCurve();
return new ECPublicKeyParameters(DSTU4145PointEncoder.decodePoint(curve, keyEnc), theDomain);
}
/**
* Derive Private Key parameters from PrivateKeyInfo. (extracted from BouncyCastle initialiser)
* @param pKeyInfo the keyInfo
* @return the PrivateKeyParameters
* @throws GordianException on error
*/
private ECPrivateKeyParameters deriveFromPrivKeyInfo(final PrivateKeyInfo pKeyInfo) throws GordianException {
try {
final ASN1Encodable privKey = pKeyInfo.parsePrivateKey();
final BigInteger myD;
if (privKey instanceof ASN1Integer) {
myD = ASN1Integer.getInstance(privKey).getPositiveValue();
} else {
final ECPrivateKey ec = ECPrivateKey.getInstance(privKey);
myD = ec.getKey();
}
return new ECPrivateKeyParameters(myD, theDomain);
} catch (IOException e) {
throw new GordianCryptoException(ERROR_PARSE, e);
}
}
}
/**
* DSTU encoder.
*/
static final class BouncyDSTUCoder implements BouncyDSACoder {
@Override
public byte[] dsaEncode(final BigInteger r,
final BigInteger s) throws GordianException {
/* Protect against exceptions */
try {
/* Access byteArrays */
final byte[] myFirst = s.toByteArray();
final byte[] mySecond = r.toByteArray();
final byte[] myResult = myFirst.length > mySecond.length
? new byte[myFirst.length * 2]
: new byte[mySecond.length * 2];
/* Build array and return */
System.arraycopy(myFirst, 0, myResult, myResult.length / 2 - myFirst.length, myFirst.length);
System.arraycopy(mySecond, 0, myResult, myResult.length - mySecond.length, mySecond.length);
return new DEROctetString(myResult).getEncoded();
} catch (Exception e) {
throw new GordianCryptoException(BouncySignature.ERROR_SIGGEN, e);
}
}
@Override
public BigInteger[] dsaDecode(final byte[] pEncoded) throws GordianException {
/* Protect against exceptions */
try {
/* Access the bytes */
final byte[] bytes = ((ASN1OctetString) ASN1Primitive.fromByteArray(pEncoded)).getOctets();
/* Build the value arrays */
final byte[] myFirst = new byte[bytes.length / 2];
final byte[] mySecond = new byte[bytes.length / 2];
System.arraycopy(bytes, 0, myFirst, 0, myFirst.length);
System.arraycopy(bytes, myFirst.length, mySecond, 0, mySecond.length);
/* Create the signature values and return */
final BigInteger[] sig = new BigInteger[2];
sig[1] = new BigInteger(1, myFirst);
sig[0] = new BigInteger(1, mySecond);
return sig;
} catch (Exception e) {
throw new GordianCryptoException(BouncySignature.ERROR_SIGPARSE, e);
}
}
}
/**
* DSTU signer.
*/
public static class BouncyDSTUSignature
extends BouncyDigestSignature {
/**
* The Signer.
*/
private final DSTU4145Signer theSigner;
/**
* The Coder.
*/
private final BouncyDSTUCoder theCoder;
/**
* Constructor.
* @param pFactory the factory
* @param pSpec the signatureSpec.
* @throws GordianException on error
*/
BouncyDSTUSignature(final BouncyFactory pFactory,
final GordianSignatureSpec pSpec) throws GordianException {
/* Initialise underlying class */
super(pFactory, pSpec, newDigest());
/* Create the signer and Coder */
theSigner = new DSTU4145Signer();
theCoder = new BouncyDSTUCoder();
}
@Override
public void initForSigning(final GordianKeyPair pKeyPair) throws GordianException {
/* Initialise detail */
BouncyKeyPair.checkKeyPair(pKeyPair);
super.initForSigning(pKeyPair);
/* Initialise and set the signer */
final BouncyECPrivateKey myPrivate = (BouncyECPrivateKey) getKeyPair().getPrivateKey();
final ParametersWithRandom myParms = new ParametersWithRandom(myPrivate.getPrivateKey(), getRandom());
theSigner.init(true, myParms);
}
@Override
public void initForVerify(final GordianKeyPair pKeyPair) throws GordianException {
/* Initialise detail */
BouncyKeyPair.checkKeyPair(pKeyPair);
super.initForVerify(pKeyPair);
/* Initialise and set the signer */
final BouncyECPublicKey myPublic = (BouncyECPublicKey) getKeyPair().getPublicKey();
theSigner.init(false, myPublic.getPublicKey());
}
@Override
public byte[] sign() throws GordianException {
/* Check that we are in signing mode */
checkMode(GordianSignatureMode.SIGN);
/* Sign the message */
final BigInteger[] myValues = theSigner.generateSignature(getDigest());
return theCoder.dsaEncode(myValues[0], myValues[1]);
}
@Override
public boolean verify(final byte[] pSignature) throws GordianException {
/* Check that we are in verify mode */
checkMode(GordianSignatureMode.VERIFY);
/* Verify the message */
final BigInteger[] myValues = theCoder.dsaDecode(pSignature);
return theSigner.verifySignature(getDigest(), myValues[0], myValues[1]);
}
/**
* Obtain new digest for DSTU signer.
* @return the new digest
*/
private static Digest newDigest() {
final byte[] myCompressed = DSTU4145Params.getDefaultDKE();
final byte[] myExpanded = new byte[EXPANDED_LEN];
for (int i = 0; i < myCompressed.length; i++) {
myExpanded[i * 2] = (byte) ((myCompressed[i] >> GordianDataConverter.NYBBLE_SHIFT)
& GordianDataConverter.NYBBLE_MASK);
myExpanded[i * 2 + 1] = (byte) (myCompressed[i] & GordianDataConverter.NYBBLE_MASK);
}
return new GOST3411Digest(myExpanded);
}
}
}