uk.ac.cam.gpe21.droidssl.mitm.crypto.key.KeyUtils.java Source code

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Here is the source code for uk.ac.cam.gpe21.droidssl.mitm.crypto.key.KeyUtils.java

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/*
 * Copyright 2013-2014 Graham Edgecombe
 *
 * 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 uk.ac.cam.gpe21.droidssl.mitm.crypto.key;

import org.bouncycastle.asn1.pkcs.PrivateKeyInfo;
import org.bouncycastle.asn1.x509.SubjectPublicKeyInfo;
import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
import org.bouncycastle.crypto.util.PrivateKeyFactory;
import org.bouncycastle.crypto.util.PrivateKeyInfoFactory;
import org.bouncycastle.crypto.util.SubjectPublicKeyInfoFactory;
import org.bouncycastle.jcajce.DefaultJcaJceHelper;
import org.bouncycastle.openssl.PEMKeyPair;
import org.bouncycastle.openssl.PEMParser;

import java.io.IOException;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

public final class KeyUtils {
    public static PrivateKey readPrivateKey(Path path) throws IOException {
        try (Reader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
            return readPrivateKey(reader);
        }
    }

    public static PrivateKey readPrivateKey(Reader reader) throws IOException {
        try (PEMParser parser = new PEMParser(reader)) {
            Object object = parser.readObject();
            if (!(object instanceof PEMKeyPair))
                throw new IOException("File does not contain a key");

            PEMKeyPair pair = (PEMKeyPair) object;

            // TODO merge messy conversion logic with that below */
            AsymmetricKeyParameter privateKey = PrivateKeyFactory.createKey(pair.getPrivateKeyInfo());
            PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.createPrivateKeyInfo(privateKey);
            KeyFactory keyFactory = new DefaultJcaJceHelper().createKeyFactory("RSA"); // TODO should we really assume RSA?
            return keyFactory.generatePrivate(new PKCS8EncodedKeySpec(privateKeyInfo.getEncoded()));
        } catch (NoSuchAlgorithmException | InvalidKeySpecException ex) {
            throw new IOException(ex);
        }
    }

    public static KeyPair convertToJca(AsymmetricCipherKeyPair keyPair)
            throws IOException, NoSuchAlgorithmException, InvalidKeySpecException {
        SubjectPublicKeyInfo publicKey = SubjectPublicKeyInfoFactory
                .createSubjectPublicKeyInfo(keyPair.getPublic());
        PrivateKeyInfo privateKey = PrivateKeyInfoFactory.createPrivateKeyInfo(keyPair.getPrivate());

        KeyFactory keyFactory = new DefaultJcaJceHelper().createKeyFactory("RSA"); // TODO should we really assume RSA?
        return new KeyPair(keyFactory.generatePublic(new X509EncodedKeySpec(publicKey.getEncoded())),
                keyFactory.generatePrivate(new PKCS8EncodedKeySpec(privateKey.getEncoded())));
    }

    private KeyUtils() {
        /* to prevent instantiation */
    }
}