Java tutorial
/******************************************************************************* * Copyright (c) 2013 Lectorius, Inc. * Authors: * Vijay Pandurangan (vijayp@mitro.co) * Evan Jones (ej@mitro.co) * Adam Hilss (ahilss@mitro.co) * * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * * You can contact the authors at inbound@mitro.co. *******************************************************************************/ package co.mitro.keyczar; import java.lang.reflect.Type; import org.keyczar.GenericKeyczar; import org.keyczar.KeyVersion; import org.keyczar.KeyczarFileReader; import org.keyczar.exceptions.KeyczarException; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonSerializationContext; import com.google.gson.JsonSerializer; public class JsonWriter { public static final class KeyczarSerializer implements JsonSerializer<GenericKeyczar> { // Everything must be final so this is thread-safe private final String password; public KeyczarSerializer(String password) { this.password = password; } @Override public JsonElement serialize(GenericKeyczar keyczar, Type typeOfKey, JsonSerializationContext context) { // key.toString() returns the serialized metadata // this is a bit gross: JSON embedded in JSON, but it makes it // easier to integrate JsonObject obj = new JsonObject(); // hack to set encrypted = true if needed String metadataString = keyczar.toString(); if (password != null && !keyczar.getMetadata().isEncrypted()) { String out = metadataString.replaceFirst("\"encrypted\":false", "\"encrypted\":true"); assert !out.equals(metadataString); metadataString = out; } obj.addProperty("meta", metadataString); for (KeyVersion version : keyczar.getVersions()) { String keyData = keyczar.getKey(version).toString(); if (password != null) { try { keyData = KeyczarPBEReader.encryptKey(keyData, password); } catch (KeyczarException e) { throw new RuntimeException(e); } } obj.addProperty(Integer.toString(version.getVersionNumber()), keyData); } return obj; } } private static final Gson gson; static { // gson itself is thread-safe. Our KeyczarSerializer must be as well. KeyczarSerializer serializer = new KeyczarSerializer(null); gson = new GsonBuilder().registerTypeAdapter(GenericKeyczar.class, serializer).create(); } /** Writes input Keyczar key as a JSON string to output. */ public static void write(GenericKeyczar input, Appendable output) { gson.toJson(input, output); } /** Returns input Keyczar key as a JSON string. */ public static String toString(GenericKeyczar input) { return gson.toJson(input); } public static void writeEncrypted(GenericKeyczar input, String password, Appendable output) { KeyczarSerializer serializer = new KeyczarSerializer(password); Gson gson = new GsonBuilder().registerTypeAdapter(GenericKeyczar.class, serializer).create(); gson.toJson(input, output); } public static void main(String[] arguments) throws KeyczarException { if (arguments.length != 1) { System.err.println("JsonWriter (input key path)"); System.err.println(" Reads a key and writes to stdout as JSON"); System.exit(1); } GenericKeyczar keyczar = new GenericKeyczar(new KeyczarFileReader(arguments[0])); write(keyczar, System.out); } }