opendaylight/netconf/netconf-ssh/src/main/java/org/opendaylight/controller/netconf/ssh/authentication/PEMGenerator.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.netconf.ssh.authentication;
  10
  11 import java.security.NoSuchAlgorithmException;
  12 import org.apache.commons.io.FileUtils;
  13 import org.bouncycastle.openssl.PEMWriter;
  14 import org.slf4j.Logger;
  15 import org.slf4j.LoggerFactory;
  16
  17 import java.io.File;
  18 import java.io.IOException;
  19 import java.io.StringWriter;
  20 import java.security.Key;
  21 import java.security.KeyPair;
  22 import java.security.KeyPairGenerator;
  23 import java.security.SecureRandom;
  24
  25 public class PEMGenerator {
  26     private static final Logger logger = LoggerFactory.getLogger(PEMGenerator.class);
  27     private static final int KEY_SIZE = 4096;
  28
  29     public static String generateTo(File privateFile) throws IOException, NoSuchAlgorithmException {
  30         KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
  31         SecureRandom sr = new SecureRandom();
  32         keyGen.initialize(KEY_SIZE, sr);
  33         KeyPair keypair = keyGen.generateKeyPair();
  34         logger.info("Generating private key to {}", privateFile.getAbsolutePath());
  35         String privatePEM = toString(keypair.getPrivate());
  36         FileUtils.write(privateFile, privatePEM);
  37         return privatePEM;
  38     }
  39
  40     private static String toString(Key key) throws IOException {
  41         try (StringWriter writer = new StringWriter()) {
  42             try (PEMWriter pemWriter = new PEMWriter(writer)) {
  43                 pemWriter.writeObject(key);
  44             }
  45             return writer.toString();
  46         }
  47     }
  48 }