org.apache.whirr.util.KeyPair.java Source code

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Here is the source code for org.apache.whirr.util.KeyPair.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.whirr.util;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.OutputStream;
import java.security.GeneralSecurityException;
import java.security.PublicKey;
import java.security.interfaces.RSAPublicKey;
import java.util.Map;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.io.IOUtils;
import org.apache.commons.ssl.PKCS8Key;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.ImmutableMap;
import com.google.common.io.Files;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;

/**
 * A convenience class for generating an RSA key pair.
 */
public class KeyPair {

    private static final Logger LOG = LoggerFactory.getLogger(KeyPair.class);

    public static Map<String, String> generate() throws JSchException {
        return generate(null);
    }

    /**
     * return a "public" -> rsa public key, "private" -> its corresponding
     *   private key
     */
    public static Map<String, String> generate(String passPhrase) throws JSchException {
        com.jcraft.jsch.KeyPair pair = com.jcraft.jsch.KeyPair.genKeyPair(new JSch(), com.jcraft.jsch.KeyPair.RSA);
        if (passPhrase != null) {
            pair.setPassphrase(passPhrase);
        }

        ByteArrayOutputStream publicKeyOut = new ByteArrayOutputStream();
        ByteArrayOutputStream privateKeyOut = new ByteArrayOutputStream();

        pair.writePublicKey(publicKeyOut, "whirr");
        pair.writePrivateKey(privateKeyOut);

        String publicKey = new String(publicKeyOut.toByteArray());
        String privateKey = new String(privateKeyOut.toByteArray());

        return ImmutableMap.<String, String>of("public", publicKey, "private", privateKey);
    }

    public static Map<String, File> generateTemporaryFiles() throws JSchException, IOException {
        return generateTemporaryFiles(null);
    }

    public static Map<String, File> generateTemporaryFiles(String passPhrase) throws JSchException, IOException {
        Map<String, String> keys = KeyPair.generate(passPhrase);

        File privateKeyFile = File.createTempFile("private", "key");
        privateKeyFile.deleteOnExit();
        Files.write(keys.get("private").getBytes(), privateKeyFile);
        setPermissionsTo600(privateKeyFile);

        File publicKeyFile = new File(privateKeyFile.getAbsolutePath() + ".pub");
        publicKeyFile.deleteOnExit();
        Files.write(keys.get("public").getBytes(), publicKeyFile);
        setPermissionsTo600(publicKeyFile);

        return ImmutableMap.<String, File>of("public", publicKeyFile, "private", privateKeyFile);
    }

    /**
     * Set file permissions to 600 (unix)
     */
    public static void setPermissionsTo600(File f) {
        f.setReadable(false, false);
        f.setReadable(true, true);

        f.setWritable(false, false);
        f.setWritable(true, true);

        f.setExecutable(false);
    }

    public static boolean sameKeyPair(File privateKeyFile, File publicKeyFile) throws IOException {
        try {
            PKCS8Key decodedKey = new PKCS8Key(new FileInputStream(privateKeyFile), null);
            PublicKey publicKey = decodedKey.getPublicKey();

            byte[] actual = encodePublicKey((RSAPublicKey) publicKey);
            byte[] expected = IOUtils.toByteArray(new FileReader(publicKeyFile));

            for (int i = 0; i < actual.length; i += 1) {
                if (actual[i] != expected[i]) {
                    return false;
                }
            }
            return true;
        } catch (GeneralSecurityException e) {
            LOG.error("Key pair validation failed", e);
            return false;
        }
    }

    private static byte[] encodePublicKey(RSAPublicKey key) throws IOException {
        ByteArrayOutputStream keyBlob = new ByteArrayOutputStream();
        write("ssh-rsa".getBytes(), keyBlob);
        write(key.getPublicExponent().toByteArray(), keyBlob);
        write(key.getModulus().toByteArray(), keyBlob);

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        out.write("ssh-rsa ".getBytes());
        out.write(Base64.encodeBase64(keyBlob.toByteArray()));

        return out.toByteArray();
    }

    private static void write(byte[] str, OutputStream os) throws IOException {
        for (int shift = 24; shift >= 0; shift -= 8)
            os.write((str.length >>> shift) & 0xFF);
        os.write(str);
    }

}