plugins/git4idea/rt/src/org/jetbrains/git4idea/http/GitAskPassApp.java

/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * 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.jetbrains.git4idea.http;

import com.intellij.openapi.util.Pair;
import com.intellij.openapi.util.text.StringUtilRt;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.git4idea.GitExternalApp;

/**
 * <p>This is a program that would be called by Git when an HTTP connection is needed, that requires authorization,
 *    and if {@code GIT_ASKPASS} variable is set to the script that invokes this program.</p>
 * <p>The program is called separately for each authorization aspect.
 *    I. e. if no username is specified, then it is started and queried for the username, and then started once again for the password.</p>
 * <p>Since Git 1.7.9 the query format is the following:
 *    <ul>
 *      <li><code>Username for 'https://bitbucket.org':</code></li>
 *      <li><code>Password for 'https://bitbucket.org':</code></li>
 *      <li><code>Password for 'https://username@bitbucket.org':</code></li>
 *    </ul>
 * </p>
 * <p>Before Git 1.7.9 the query didn't contain the URL:
 *   <ul>
 *     <li><code>Username: </code></li>
 *     <li><code>Password: </code></li>
 *   </ul>
 * </p>
 * <p>Git expects the reply from the program's standard output.</p>
 *
 * @author Kirill Likhodedov
 */
public class GitAskPassApp implements GitExternalApp {

  // STDOUT is used to provide credentials to Git process; STDERR is used to print error message to the main IDEA command line.
  @SuppressWarnings("UseOfSystemOutOrSystemErr")
  public static void main(String[] args) {
    try {
      if (args.length < 1) {
        throw new IllegalArgumentException("No arguments specified!");
      }

      Pair<Boolean, String> arguments = parseArguments(args[0]);
      boolean usernameNeeded = arguments.getFirst();
      String url = arguments.getSecond();

      int handler = Integer.parseInt(getNotNull(GitAskPassXmlRpcHandler.GIT_ASK_PASS_HANDLER_ENV));
      int xmlRpcPort = Integer.parseInt(getNotNull(GitAskPassXmlRpcHandler.GIT_ASK_PASS_PORT_ENV));
      GitAskPassXmlRpcClient xmlRpcClient = new GitAskPassXmlRpcClient(xmlRpcPort);

      if (usernameNeeded) {
        String username = xmlRpcClient.askUsername(handler, url);
        System.out.println(username);
      }
      else {
        String pass = xmlRpcClient.askPassword(handler, url);
        System.out.println(pass);
      }
    }
    catch (Throwable t) {
      System.err.println(t.getMessage());
      t.printStackTrace(System.err);
    }
  }

  @NotNull
  private static String getNotNull(@NotNull String env) {
    String handlerValue = System.getenv(env);
    if (handlerValue == null) {
      throw new IllegalStateException(env + " environment variable is not defined!");
    }
    return handlerValue;
  }

  @NotNull
  private static Pair<Boolean, String> parseArguments(@NotNull String arg) {
    boolean username = StringUtilRt.startsWithIgnoreCase(arg, "username");
    String url;
    String[] split = arg.split(" ");
    if (split.length > 2) {
      url = parseUrl(split[2]);
    }
    else {
      url = ""; // XML RPC doesn't like nulls
    }
    return Pair.create(username, url);
  }

  private static String parseUrl(@NotNull String urlArg) {
    // un-quote and remove the trailing colon
    String url = urlArg;
    if (url.startsWith("'")) {
      url = url.substring(1);
    }
    if (url.endsWith(":")) {
      url = url.substring(0, url.length() - 1);
    }
    if (url.endsWith("'")) {
      url = url.substring(0, url.length() - 1);
    }
    return url;
  }

}