# SSLHelper.java

    /*
    ** Module   : SSLHelper.java
    ** Abstract : SSL processing convenience methods
    **
    ** Copyright (c) 2016-2017, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- -------------------------------Description-----------------------------------
    ** 001 GES 20160113 First version.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */

    package com.goldencode.p2j.security;

    import java.io.*;
    import java.util.*;
    import java.security.*;
    import java.security.cert.*;
    import javax.net.ssl.*;

    /**
     * Provides static SSL processing convenience methods.
     */
    public class SSLHelper
    {
       /** Detailed return codes. */
       public static enum ErrorCode
       {
          NO_ERROR,
          NULL_KEYSTORE,
          NULL_FILENAME,
          FILE_DOESNT_EXIST,
          LOAD_IO_FAILURE,
          LOAD_ALGORITHM_FAILURE,
          LOAD_CERT_FAILURE,
          INVALID_RESULT_ARRAY,
          KEYMANAGER_INIT_FAILURE,
          KEYMANAGER_ALGORITHM_FAILURE,
          KEY_READ_FAILURE,
          UNEXPECTED_FAILURE
       };

       /**
        * Private constructor to disallow instantiation.
        */
       private SSLHelper()
       {
       }

       /**
        * Given a valid key store instance and a filename to an existing file that
        * is a valid keystore, the contents will be loaded from the file system.
        *
        * @param    ks
        *           The in-memory key store into which to load.
        * @param    fname
        *           The filename of the file system resource that contains the key
        *           store from which to load.
        * @param    pw
        *           A valid password needed to decrypt the contents during load or
        *           <code>null</code> if no password is needed.
        *
        * @return   <code>ErrorCode.NO_ERROR</code> on success, otherwise a descriptive
        *           return code to explain the failure.
        */
       public static ErrorCode loadKeyStoreFromFile(KeyStore ks, String fname, String pw)
       {
          if (ks == null)
          {
             return ErrorCode.NULL_KEYSTORE;
          }

          if (fname == null)
          {
             return ErrorCode.NULL_FILENAME;
          }

          InputStream kis = null;

          try
          {
             File file = new File(fname);

             if (file.exists())
             {
                kis = new FileInputStream(fname);
             }
             else
             {
                return ErrorCode.FILE_DOESNT_EXIST;
             }

             ks.load(kis, (pw == null) ? null : pw.toCharArray());
          }

          catch (NullPointerException npe)
          {
             // should not occur
             return ErrorCode.UNEXPECTED_FAILURE;
          }

          catch (FileNotFoundException fnf)
          {
             // should not occur
             return ErrorCode.FILE_DOESNT_EXIST;
          }

          catch (IOException ioe)
          {
             return ErrorCode.LOAD_IO_FAILURE;
          }

          catch (NoSuchAlgorithmException nsa)
          {
             return ErrorCode.LOAD_ALGORITHM_FAILURE;
          }

          catch (CertificateException ce)
          {
             return ErrorCode.LOAD_CERT_FAILURE;
          }

          finally
          {
             if (kis != null)
             {
                try
                {
                   kis.close();
                }

                catch (IOException ioe)
                {
                   // nothing to do, ignore this
                }
             }
          }

          return ErrorCode.NO_ERROR;
       }

       /**
        * Initialize the key manager array using the given key store.
        *
        * @param    ks
        *           Key store from which to initialize the key managers.
        * @param    pw
        *           Key entry password or <code>null</code> if not needed.
        * @param    result
        *           An array into which the key manager array reference can be returned. The
        *           array size must be at least 1 element and the 0 index element will be
        *           replaced with a <code>KeyManager[]</code> reference on success.
        *
        * @return   <code>ErrorCode.NO_ERROR</code> on success, otherwise a descriptive
        *           return code to explain the failure.
        */
       public static ErrorCode initKeyManagers(KeyStore ks, String pw, Object[] result)
       {
          if (ks == null)
          {
             return ErrorCode.NULL_KEYSTORE;
          }

          if (result == null || result.length < 1)
          {
             return ErrorCode.INVALID_RESULT_ARRAY;
          }

          try
          {

             KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");

             kmf.init(ks, (pw == null) ? null : pw.toCharArray());

             result[0] = kmf.getKeyManagers();
          }

          catch (NoSuchAlgorithmException nsa)
          {
             return ErrorCode.KEYMANAGER_ALGORITHM_FAILURE;
          }

          catch (KeyStoreException kse)
          {
             return ErrorCode.KEYMANAGER_INIT_FAILURE;
          }

          catch (UnrecoverableKeyException uke)
          {
             return ErrorCode.KEY_READ_FAILURE;
          }

          return ErrorCode.NO_ERROR;
       }
    }