gerrit-gpg/src/main/java/com/google/gerrit/gpg/SignedPushPreReceiveHook.java

// Copyright (C) 2015 The Android Open Source Project
//
// 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.google.gerrit.gpg;

import com.google.gerrit.server.config.AllUsersName;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.inject.Inject;
import com.google.inject.Singleton;

import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.transport.PreReceiveHook;
import org.eclipse.jgit.transport.PushCertificate;
import org.eclipse.jgit.transport.ReceiveCommand;
import org.eclipse.jgit.transport.ReceivePack;

import java.io.IOException;
import java.util.Collection;

/**
 * Pre-receive hook to check signed pushes.
 * <p>
 * If configured, prior to processing any push using
 * {@link com.google.gerrit.server.git.ReceiveCommits}, requires that any push
 * certificate present must be valid.
 */
@Singleton
public class SignedPushPreReceiveHook implements PreReceiveHook {
  private final GitRepositoryManager repoManager;
  private final AllUsersName allUsers;
  private final PublicKeyChecker keyChecker;

  @Inject
  public SignedPushPreReceiveHook(
      GitRepositoryManager repoManager,
      AllUsersName allUsers,
      PublicKeyChecker keyChecker) {
    this.repoManager = repoManager;
    this.allUsers = allUsers;
    this.keyChecker = keyChecker;
  }

  @Override
  public void onPreReceive(ReceivePack rp,
      Collection<ReceiveCommand> commands) {
    PushCertificate cert = rp.getPushCertificate();
    if (cert == null) {
      return;
    }
    PushCertificateChecker checker = new PushCertificateChecker(keyChecker) {
      @Override
      protected Repository getRepository() throws IOException {
        return repoManager.openRepository(allUsers);
      }

      @Override
      protected boolean shouldClose(Repository repo) {
        return true;
      }
    };
    CheckResult result = checker.check(cert);
    if (!result.isOk()) {
      for (String problem : result.getProblems()) {
        rp.sendMessage(problem);
      }
      reject(commands, "invalid push cert");
    }
  }

  private static void reject(Collection<ReceiveCommand> commands,
      String reason) {
    for (ReceiveCommand cmd : commands) {
      if (cmd.getResult() == ReceiveCommand.Result.NOT_ATTEMPTED) {
        cmd.setResult(ReceiveCommand.Result.REJECTED_OTHER_REASON, reason);
      }
    }
  }
}