/*
 * Copyright 1999-2010 University of Chicago
 *
 * 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 org.globus.tools;

import java.security.GeneralSecurityException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import org.globus.gsi.OpenSSLKey;
import org.globus.gsi.CertUtil;
import org.globus.gsi.bc.BouncyCastleOpenSSLKey;
import org.globus.util.Util;
import org.globus.common.CoGProperties;
import org.globus.common.Version;

/** Changes the Passphrase.
 * <pre>
 * Syntax: java ChangePassPhrase [-help] [-version] [-file private_key_file]
  * Changes the passphrase that protects the private key. If the -file
  * argument is not given, the default location of the file containing
  * the private key is assumed:
  *   --  Config.getUserKeyFile()
  * Options
  *   -help, -usage                Display usage
  *   -version                     Display version
  *   -file location               Change passphrase on key stored in the
  *                                file at the non-standard
  *                                location 'location';
 * </pre>
 */
public class ChangePassPhrase {

    private static String message =
	"\n" +
	"Syntax: java ChangePassPhrase [-help] [-version] [-file private_key_file]\n\n" +
	"\tChanges the passphrase that protects the private key. If the\n" +
	"\t-file argument is not given, the default location of the file\n" +
	"\tcontaining the private key is assumed:\n\n" +
	"\t  -- " + CoGProperties.getDefault().getUserKeyFile() + "\n\n" +
	"\tOptions\n" +
	"\t-help | -usage\n" +
	"\t\tDisplay usage.\n" +
	"\t-version\n" +
	"\t\tDisplay version.\n" +
	"\t-file location\n" +
	"\t\tChange passphrase on key stored in the file at\n" +
	"\t\tthe non-standard location 'location'.\n\n";

    public static void main(String args[]) {

	String file         = null;
	boolean error       = false;
	boolean debug       = false;

	for (int i = 0; i < args.length; i++) {
	    if (args[i].equalsIgnoreCase("-file")) {
		file = args[++i];
	    } else if (args[i].equalsIgnoreCase("-version")) {
		System.err.println(Version.getVersion());
		System.exit(1);
	    } else if (args[i].equalsIgnoreCase("-debug")) {
		debug = true;
	    } else if (args[i].equalsIgnoreCase("-help") ||
		       args[i].equalsIgnoreCase("-usage")) {
		System.err.println(message);
		System.exit(1);
	    } else {
		System.err.println("Error: argument not recognized : " + args[i]);
		error = true;
	    }
	}

	if (error) {
	    System.err.println("\nUsage: java ChangePassPhrase [-help] [-version] [-file private_key_file]\n");
	    System.err.println("Use -help to display full usage.");
	    System.exit(1);
	}

	CertUtil.init();

	if (file == null) {
	    file = CoGProperties.getDefault().getUserKeyFile();
	}

	OpenSSLKey key = null;
	String pwd1, pwd2 = null;

	try {
	    key = new BouncyCastleOpenSSLKey(file);

	    if (key.isEncrypted()) {
		pwd1 = Util.getPrivateInput("Enter OLD pass phrase: ");
		if (pwd1 == null || pwd1.length() == 0) return;
		try {
		    key.decrypt(pwd1);
		} catch(Exception e) {
		    System.err.println("Error: Wrong pass phrase or key is invalid.");
		    if (debug) {
			e.printStackTrace();
		    }
		    System.exit(1);
		}
	    }

	    pwd1 = Util.getPrivateInput("Enter NEW pass phrase: ");
	    if (pwd1 == null || pwd1.length() == 0) return;

	    pwd2 = Util.getPrivateInput("Verifying password - Enter NEW pass phrase: ");
	    if (pwd2 == null || pwd2.length() == 0) return;

	    if (!pwd1.equals(pwd2)) {
		System.err.println("Error: Passwords do not match!");
		System.exit(1);
	    }

	    key.encrypt(pwd1);

	    File newFile = Util.createFile(file + ".new");
            Util.setOwnerAccessOnly(newFile.getAbsolutePath());
	    File oldFile = Util.createFile(file + ".old");
            Util.setOwnerAccessOnly(oldFile.getAbsolutePath());
	    File crFile  = Util.createFile(file);
            Util.setOwnerAccessOnly(crFile.getAbsolutePath());

	    copy(crFile, oldFile);

	    key.writeTo(newFile.getAbsolutePath());

	    if (!crFile.delete()) {
		System.err.println("Error: failed to remove " + file + " file.");
		System.exit(1);
	    }

	    if (newFile.renameTo(crFile)) {
		System.out.println("Pass phrase successfully changed.");
	    } else {
		System.err.println("Error: failed to rename the files.");
		System.exit(1);
	    }

	} catch(GeneralSecurityException e) {
	    System.err.println("Error: " + e.getMessage());
	    System.exit(1);
	} catch(Exception e) {
	    System.err.println("Unable to load the private key : " + e.getMessage());
	    System.exit(1);
	}

    }

    private static void copy(File srcFile, File dstFile)
	throws IOException {

	InputStream in   = null;
	OutputStream out = null;
	byte [] buffer   = new byte[1024];
	int bytes        = 0;

	try {
	    in  = new FileInputStream(srcFile);
	    out = new FileOutputStream(dstFile);

	    Util.setOwnerAccessOnly(dstFile.getAbsolutePath());

	    while( (bytes = in.read(buffer)) != -1) {
		out.write(buffer, 0, bytes);
		out.flush();
	    }

	} finally {
	    try {
		if (in != null) in.close();
		if (out != null) out.close();
	    } catch(Exception e) {}
	}
    }

}