All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.google.gerrit.sshd.SuExec Maven / Gradle / Ivy

There is a newer version: 3.10.1
Show newest version
// Copyright (C) 2010 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.sshd;

import static java.nio.charset.StandardCharsets.UTF_8;

import com.google.common.base.Throwables;
import com.google.common.util.concurrent.Atomics;
import com.google.gerrit.entities.Account;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.DynamicOptions;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.PeerDaemonUser;
import com.google.gerrit.server.config.AuthConfig;
import com.google.gerrit.server.permissions.GlobalPermission;
import com.google.gerrit.server.permissions.PermissionBackend;
import com.google.gerrit.server.permissions.PermissionBackendException;
import com.google.gerrit.sshd.SshScope.Context;
import com.google.inject.Inject;
import java.io.IOException;
import java.net.SocketAddress;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.sshd.server.Environment;
import org.apache.sshd.server.channel.ChannelSession;
import org.apache.sshd.server.command.Command;
import org.kohsuke.args4j.Argument;
import org.kohsuke.args4j.Option;

/**
 * Executes any other command as a different user identity.
 *
 * 

The calling user must be authenticated as a {@link PeerDaemonUser}, which usually requires * public key authentication using this daemon's private host key, or a key on this daemon's peer * host key ring. */ public final class SuExec extends BaseCommand { private final SshScope sshScope; private final DispatchCommandProvider dispatcher; private final PermissionBackend permissionBackend; private boolean enableRunAs; private CurrentUser caller; private SshSession session; private IdentifiedUser.GenericFactory userFactory; private SshScope.Context callingContext; @Option(name = "--as", required = true) private Account.Id accountId; @Option(name = "--from") private SocketAddress peerAddress; @Argument(index = 0, multiValued = true, metaVar = "COMMAND") private List args = new ArrayList<>(); private final AtomicReference atomicCmd; @Inject SuExec( final SshScope sshScope, @CommandName(Commands.ROOT) final DispatchCommandProvider dispatcher, PermissionBackend permissionBackend, final CurrentUser caller, final SshSession session, final IdentifiedUser.GenericFactory userFactory, final SshScope.Context callingContext, AuthConfig config) { this.sshScope = sshScope; this.dispatcher = dispatcher; this.permissionBackend = permissionBackend; this.caller = caller; this.session = session; this.userFactory = userFactory; this.callingContext = callingContext; this.enableRunAs = config.isRunAsEnabled(); atomicCmd = Atomics.newReference(); } @Override public void start(ChannelSession channel, Environment env) throws IOException { try (DynamicOptions pluginOptions = new DynamicOptions(injector, dynamicBeans)) { checkCanRunAs(); parseCommandLine(pluginOptions); final Context ctx = callingContext.subContext(newSession(), join(args)); final Context old = sshScope.set(ctx); try { final BaseCommand cmd = dispatcher.get(); cmd.setArguments(args.toArray(new String[args.size()])); provideStateTo(cmd); atomicCmd.set(cmd); cmd.start(channel, env); } finally { sshScope.set(old); } } catch (UnloggedFailure e) { String msg = e.getMessage(); if (!msg.endsWith("\n")) { msg += "\n"; } err.write(msg.getBytes(UTF_8)); err.flush(); onExit(1); } } private void checkCanRunAs() throws UnloggedFailure { if (caller instanceof PeerDaemonUser) { // OK. } else if (!enableRunAs) { throw die("suexec disabled by auth.enableRunAs = false"); } else { try { permissionBackend.user(caller).check(GlobalPermission.RUN_AS); } catch (AuthException e) { throw die("suexec not permitted", e); } catch (PermissionBackendException e) { throw die("suexec not available", e); } } } private SshSession newSession() { final SocketAddress peer; if (peerAddress == null) { peer = session.getRemoteAddress(); } else { peer = peerAddress; } if (caller instanceof PeerDaemonUser) { caller = null; } return new SshSession(session, peer, userFactory.runAs(peer, accountId, caller)); } private static String join(List args) { StringBuilder r = new StringBuilder(); for (String a : args) { if (r.length() > 0) { r.append(" "); } r.append(a); } return r.toString(); } @Override public void destroy(ChannelSession channel) { Command cmd = atomicCmd.getAndSet(null); if (cmd != null) { try { cmd.destroy(channel); } catch (Exception e) { Throwables.throwIfUnchecked(e); throw new RuntimeException(e); } } } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy