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 org.apache.commons.io.FileUtils;
  12 import org.bouncycastle.openssl.PEMWriter;
  13 import org.slf4j.Logger;
  14 import org.slf4j.LoggerFactory;
  15
  16 import java.io.File;
  17 import java.io.IOException;
  18 import java.io.StringWriter;
  19 import java.security.Key;
  20 import java.security.KeyPair;
  21 import java.security.KeyPairGenerator;
  22 import java.security.SecureRandom;
  23
  24 public class PEMGenerator {
  25     private static final Logger logger = LoggerFactory.getLogger(PEMGenerator.class);
  26     private static final int KEY_SIZE = 4096;
  27
  28     public static String generateTo(File privateFile) throws Exception {
  29         KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA");
  30         SecureRandom sr = new SecureRandom();
  31         keyGen.initialize(KEY_SIZE, sr);
  32         KeyPair keypair = keyGen.generateKeyPair();
  33         logger.info("Generating private key to {}", privateFile.getAbsolutePath());
  34         String privatePEM = toString(keypair.getPrivate());
  35         FileUtils.write(privateFile, privatePEM);
  36         return privatePEM;
  37     }
  38
  39     private static String toString(Key key) throws IOException {
  40         try (StringWriter writer = new StringWriter()) {
  41             try (PEMWriter pemWriter = new PEMWriter(writer)) {
  42                 pemWriter.writeObject(key);
  43             }
  44             return writer.toString();
  45         }
  46     }
  47 }