Java tutorial
/* * Copyright 2015 floragunn UG (haftungsbeschrnkt) * * 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 com.floragunn.searchguard.tools; import java.io.Console; import java.util.Arrays; import java.util.Objects; import java.util.Scanner; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.CommandLineParser; import org.apache.commons.cli.DefaultParser; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.Option; import org.apache.commons.cli.Options; import com.floragunn.searchguard.crypto.BCrypt; public class Hasher { public static void main(final String[] args) { final Options options = new Options(); final HelpFormatter formatter = new HelpFormatter(); options.addOption( Option.builder("p").argName("password").hasArg().desc("Cleartext password to hash").build()); options.addOption(Option.builder("env").argName("name environment variable").hasArg() .desc("name environment variable to read password from").build()); final CommandLineParser parser = new DefaultParser(); try { final CommandLine line = parser.parse(options, args); if (line.hasOption("p")) { System.out.println(hash(line.getOptionValue("p").getBytes("UTF-8"))); } else if (line.hasOption("env")) { final String pwd = System.getenv(line.getOptionValue("env")); if (pwd == null || pwd.isEmpty()) { throw new Exception("No environment variable '" + line.getOptionValue("env") + "' set"); } System.out.println(hash(pwd.getBytes("UTF-8"))); } else { final Console console = System.console(); if (console == null) { throw new Exception("Cannot allocate a console"); } final char[] passwd = console.readPassword("[%s]", "Password:"); System.out.println(hash(new String(passwd).getBytes("UTF-8"))); } } catch (final Exception exp) { System.err.println("Parsing failed. Reason: " + exp.getMessage()); formatter.printHelp("hasher.sh", options, true); System.exit(-1); } } public static String hash(final byte[] clearTextPassword) { return BCrypt.hashpw(Objects.requireNonNull(clearTextPassword), BCrypt.gensalt(12)); } }