be.atbash.ee.security.octopus.nimbus.util.KeyUtils Maven / Gradle / Ivy
/*
* Copyright 2017-2022 Rudy De Busscher (https://www.atbash.be)
*
* 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 be.atbash.ee.security.octopus.nimbus.util;
import be.atbash.ee.security.octopus.keys.AtbashKey;
import be.atbash.ee.security.octopus.nimbus.jose.crypto.bc.BouncyCastleProviderSingleton;
import be.atbash.ee.security.octopus.nimbus.jwk.JWKIdentifiers;
import be.atbash.util.exception.AtbashUnexpectedException;
import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPrivateKey;
import org.bouncycastle.jce.ECNamedCurveTable;
import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec;
import org.bouncycastle.jce.spec.ECParameterSpec;
import org.bouncycastle.jce.spec.ECPublicKeySpec;
import org.bouncycastle.math.ec.ECPoint;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.Key;
import java.security.KeyFactory;
import java.security.PublicKey;
import java.security.interfaces.RSAPrivateCrtKey;
import java.security.spec.RSAPublicKeySpec;
/**
* JCA key utilities.
*
* Based on code by Vladimir Dzhuvinov
*/
public final class KeyUtils {
/**
* Returns the specified secret key as a secret key with its algorithm
* set to "AES".
*
* @param secretKey The secret key, {@code null} if not specified.
* @return The AES secret key, {@code null} if not specified.
*/
public static SecretKey toAESKey(SecretKey secretKey) {
if (secretKey == null) {
return null;
}
return new SecretKeySpec(secretKey.getEncoded(), "AES");
}
public static PublicKey getPublicKey(AtbashKey atbashKey) {
Key key = atbashKey.getKey();
if (key instanceof RSAPrivateCrtKey) {
RSAPrivateCrtKey rsaPrivateCrtKey = (RSAPrivateCrtKey) key;
RSAPublicKeySpec publicKeySpec = new RSAPublicKeySpec(rsaPrivateCrtKey.getModulus(), rsaPrivateCrtKey.getPublicExponent());
try {
KeyFactory keyFactory = KeyFactory.getInstance(JWKIdentifiers.RSA_KEY_TYPE, BouncyCastleProviderSingleton.getInstance());
return keyFactory.generatePublic(publicKeySpec);
} catch (Exception e) {
throw new AtbashUnexpectedException(e);
}
}
if (key instanceof BCECPrivateKey) {
BCECPrivateKey bcecPrivateKey = (BCECPrivateKey) key;
ECNamedCurveParameterSpec parameters = (ECNamedCurveParameterSpec) bcecPrivateKey.getParameters();
try {
KeyFactory keyFactory = KeyFactory.getInstance(JWKIdentifiers.ELLIPTIC_CURVE_KEY_TYPE, BouncyCastleProviderSingleton.getInstance());
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec(parameters.getName());
ECPoint Q = ecSpec.getG().multiply(bcecPrivateKey.getD());
ECPublicKeySpec pubSpec = new ECPublicKeySpec(Q, ecSpec);
return keyFactory.generatePublic(pubSpec);
} catch (Exception e) {
throw new AtbashUnexpectedException(e);
}
}
throw new UnsupportedOperationException("TODO");
}
/**
* Prevents public instantiation.
*/
private KeyUtils() {
}
}