Revise SSH public key integration with AuthenticationManager

James Moger

2014-03-14 44e2ee1d05a9d455ae60dd64058b31f006d551b7

 src/main/java/com/gitblit/transport/ssh/SshDaemon.java

@@ -1,331 +1,260 @@
/*

 * Copyright 2014 gitblit.com.

 *

 * 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.gitblit.transport.ssh;



import java.io.File;

import java.io.IOException;

import java.net.InetSocketAddress;

import java.net.SocketAddress;

import java.security.InvalidKeyException;

import java.text.MessageFormat;

import java.util.Arrays;

import java.util.Iterator;

import java.util.LinkedList;

import java.util.List;

import java.util.concurrent.atomic.AtomicBoolean;



import javax.inject.Inject;



import org.apache.mina.core.future.IoFuture;

import org.apache.mina.core.future.IoFutureListener;

import org.apache.mina.core.session.IoSession;

import org.apache.mina.transport.socket.SocketSessionConfig;

import org.apache.sshd.SshServer;

import org.apache.sshd.common.Channel;

import org.apache.sshd.common.Cipher;

import org.apache.sshd.common.Compression;

import org.apache.sshd.common.KeyExchange;

import org.apache.sshd.common.KeyPairProvider;

import org.apache.sshd.common.Mac;

import org.apache.sshd.common.NamedFactory;

import org.apache.sshd.common.Session;

import org.apache.sshd.common.Signature;

import org.apache.sshd.common.cipher.AES128CBC;

import org.apache.sshd.common.cipher.AES192CBC;

import org.apache.sshd.common.cipher.AES256CBC;

import org.apache.sshd.common.cipher.BlowfishCBC;

import org.apache.sshd.common.cipher.TripleDESCBC;

import org.apache.sshd.common.compression.CompressionNone;

import org.apache.sshd.common.mac.HMACMD5;

import org.apache.sshd.common.mac.HMACMD596;

import org.apache.sshd.common.mac.HMACSHA1;

import org.apache.sshd.common.mac.HMACSHA196;

import org.apache.sshd.common.random.BouncyCastleRandom;

import org.apache.sshd.common.random.SingletonRandomFactory;

import org.apache.sshd.common.signature.SignatureDSA;

import org.apache.sshd.common.signature.SignatureRSA;

import org.apache.sshd.common.util.SecurityUtils;

import org.apache.sshd.server.CommandFactory;

import org.apache.sshd.server.FileSystemFactory;

import org.apache.sshd.server.FileSystemView;

import org.apache.sshd.server.ForwardingFilter;

import org.apache.sshd.server.PublickeyAuthenticator;

import org.apache.sshd.server.SshFile;

import org.apache.sshd.server.UserAuth;

import org.apache.sshd.server.auth.UserAuthPublicKey;

import org.apache.sshd.server.channel.ChannelDirectTcpip;

import org.apache.sshd.server.channel.ChannelSession;

import org.apache.sshd.server.kex.DHG1;

import org.apache.sshd.server.kex.DHG14;

import org.apache.sshd.server.keyprovider.PEMGeneratorHostKeyProvider;

import org.apache.sshd.server.session.ServerSession;

import org.apache.sshd.server.session.SessionFactory;

import org.eclipse.jgit.internal.JGitText;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;



import com.gitblit.IStoredSettings;

import com.gitblit.Keys;

import com.gitblit.manager.IGitblit;

import com.gitblit.utils.IdGenerator;

import com.gitblit.utils.StringUtils;



/**

 * Manager for the ssh transport. Roughly analogous to the

 * {@link com.gitblit.git.GitDaemon} class.

 *

 * @author Eric Myhre

 *

 */

public class SshDaemon extends SshServer {



   private final Logger log = LoggerFactory.getLogger(SshDaemon.class);



   /**

    * 22: IANA assigned port number for ssh. Note that this is a distinct concept

    * from gitblit's default conf for ssh port -- this "default" is what the git

    * protocol itself defaults to if it sees and ssh url without a port.

    */

   public static final int DEFAULT_PORT = 22;



   private static final String HOST_KEY_STORE = "sshKeyStore.pem";



   private InetSocketAddress myAddress;



   private AtomicBoolean run;



   @SuppressWarnings("unused")

    private IGitblit gitblit;



   /**

    * Construct the Gitblit SSH daemon.

    *

    * @param gitblit

    */

   @Inject

   SshDaemon(IGitblit gitblit, IdGenerator idGenerator, SshCommandFactory factory) {

       this.gitblit = gitblit;

      IStoredSettings settings = gitblit.getSettings();

      int port = settings.getInteger(Keys.git.sshPort, 0);

      String bindInterface = settings.getString(Keys.git.sshBindInterface, "localhost");



      if (StringUtils.isEmpty(bindInterface)) {

         myAddress = new InetSocketAddress(port);

      } else {

         myAddress = new InetSocketAddress(bindInterface, port);

      }



      setPort(myAddress.getPort());

      setHost(myAddress.getHostName());

      setup();

      setKeyPairProvider(new PEMGeneratorHostKeyProvider(

          new File(gitblit.getBaseFolder(), HOST_KEY_STORE).getPath()));

      setPublickeyAuthenticator(new SshKeyAuthenticator(gitblit));



      run = new AtomicBoolean(false);

      setCommandFactory(factory);

      setSessionFactory(newSessionFactory(idGenerator));

   }



   SessionFactory newSessionFactory(final IdGenerator idGenerator) {

     return new SessionFactory() {

        @Override

        protected ServerSession createSession(final IoSession io) throws Exception {

            log.info("connection accepted on " + io);

            if (io.getConfig() instanceof SocketSessionConfig) {

                final SocketSessionConfig c = (SocketSessionConfig) io.getConfig();

                c.setKeepAlive(true);

            }

            ServerSession s = (ServerSession) super.createSession(io);

            SocketAddress peer = io.getRemoteAddress();

            SshSession session = new SshSession(idGenerator.next(), peer);

            s.setAttribute(SshSession.KEY, session);

            io.getCloseFuture().addListener(new IoFutureListener<IoFuture>() {

                @Override

                public void operationComplete(IoFuture future) {

                    log.info("connection closed on " + io);

                }

            });

            return s;

          }

        };

   }



   public int getPort() {

      return myAddress.getPort();

   }



   public String formatUrl(String gituser, String servername, String repository) {

      if (getPort() == DEFAULT_PORT) {

         // standard port

         return MessageFormat.format("{0}@{1}/{2}", gituser, servername, repository);

      } else {

         // non-standard port

         return MessageFormat.format("ssh://{0}@{1}:{2,number,0}/{3}", gituser, servername, getPort(), repository);

      }

   }



   /**

    * Start this daemon on a background thread.

    *

    * @throws IOException

    *             the server socket could not be opened.

    * @throws IllegalStateException

    *             the daemon is already running.

    */

   public synchronized void start() throws IOException {

      if (run.get()) {

         throw new IllegalStateException(JGitText.get().daemonAlreadyRunning);

      }



      super.start();

      run.set(true);



      log.info(MessageFormat.format("SSH Daemon is listening on {0}:{1,number,0}",

            myAddress.getAddress().getHostAddress(), myAddress.getPort()));

   }



   /** @return true if this daemon is receiving connections. */

   public boolean isRunning() {

      return run.get();

   }



   /** Stop this daemon. */

   public synchronized void stop() {

      if (run.get()) {

         log.info("SSH Daemon stopping...");

         run.set(false);



         try {

            super.stop();

         } catch (InterruptedException e) {

            log.error("SSH Daemon stop interrupted", e);

         }

      }

   }



      /**

     * Performs most of default configuration (setup random sources, setup ciphers,

     * etc; also, support for forwarding and filesystem is explicitly disallowed).

     *

     * {@link #setKeyPairProvider(KeyPairProvider)} and

     * {@link #setPublickeyAuthenticator(PublickeyAuthenticator)} are left for you.

     * And applying {@link #setCommandFactory(CommandFactory)} is probably wise if you

     * want something to actually happen when users do successfully authenticate.

     */

    @SuppressWarnings("unchecked")

    public void setup() {

        if (!SecurityUtils.isBouncyCastleRegistered())

            throw new RuntimeException("BC crypto not available");



        setKeyExchangeFactories(Arrays.<NamedFactory<KeyExchange>>asList(

                new DHG14.Factory(),

                new DHG1.Factory())

        );



        setRandomFactory(new SingletonRandomFactory(new BouncyCastleRandom.Factory()));



        setupCiphers();



        setCompressionFactories(Arrays.<NamedFactory<Compression>>asList(

                new CompressionNone.Factory())

        );



        setMacFactories(Arrays.<NamedFactory<Mac>>asList(

                new HMACMD5.Factory(),

                new HMACSHA1.Factory(),

                new HMACMD596.Factory(),

                new HMACSHA196.Factory())

        );



        setChannelFactories(Arrays.<NamedFactory<Channel>>asList(

                new ChannelSession.Factory(),

                new ChannelDirectTcpip.Factory())

        );



        setSignatureFactories(Arrays.<NamedFactory<Signature>>asList(

                new SignatureDSA.Factory(),

                new SignatureRSA.Factory())

        );



        setFileSystemFactory(new FileSystemFactory() {

            @Override

            public FileSystemView createFileSystemView(Session session) throws IOException {

                return new FileSystemView() {

                    @Override

                    public SshFile getFile(SshFile baseDir, String file) {

                        return null;

                    }



                    @Override

                    public SshFile getFile(String file) {

                        return null;

                    }

                };

            }

        });



        setForwardingFilter(new ForwardingFilter() {

            @Override

            public boolean canForwardAgent(ServerSession session) {

                return false;

            }



            @Override

            public boolean canForwardX11(ServerSession session) {

                return false;

            }



            @Override

            public boolean canConnect(InetSocketAddress address, ServerSession session) {

                return false;

            }



            @Override

            public boolean canListen(InetSocketAddress address, ServerSession session) {

                return false;

            }

        });



        setUserAuthFactories(Arrays.<NamedFactory<UserAuth>>asList(

                new UserAuthPublicKey.Factory())

        );

    }



    protected void setupCiphers() {

        List<NamedFactory<Cipher>> avail = new LinkedList<NamedFactory<Cipher>>();

        avail.add(new AES128CBC.Factory());

        avail.add(new TripleDESCBC.Factory());

        avail.add(new BlowfishCBC.Factory());

        avail.add(new AES192CBC.Factory());

        avail.add(new AES256CBC.Factory());



        for (Iterator<NamedFactory<Cipher>> i = avail.iterator(); i.hasNext();) {

            final NamedFactory<Cipher> f = i.next();

            try {

                final Cipher c = f.create();

                final byte[] key = new byte[c.getBlockSize()];

                final byte[] iv = new byte[c.getIVSize()];

                c.init(Cipher.Mode.Encrypt, key, iv);

            } catch (InvalidKeyException e) {

                i.remove();

            } catch (Exception e) {

                i.remove();

            }

        }

        setCipherFactories(avail);

    }

}

/*
 * Copyright 2014 gitblit.com.
 *
 * 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.gitblit.transport.ssh;

import java.io.File;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.text.MessageFormat;
import java.util.concurrent.atomic.AtomicBoolean;

import javax.inject.Singleton;

import org.apache.sshd.SshServer;
import org.apache.sshd.common.io.IoServiceFactoryFactory;
import org.apache.sshd.common.io.mina.MinaServiceFactoryFactory;
import org.apache.sshd.common.io.nio2.Nio2ServiceFactoryFactory;
import org.apache.sshd.server.keyprovider.PEMGeneratorHostKeyProvider;
import org.eclipse.jgit.internal.JGitText;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.gitblit.IStoredSettings;
import com.gitblit.Keys;
import com.gitblit.git.GitblitReceivePackFactory;
import com.gitblit.git.GitblitUploadPackFactory;
import com.gitblit.git.RepositoryResolver;
import com.gitblit.manager.IGitblit;
import com.gitblit.transport.ssh.commands.CreateRepository;
import com.gitblit.transport.ssh.commands.DispatchCommand;
import com.gitblit.transport.ssh.commands.Receive;
import com.gitblit.transport.ssh.commands.ReviewCommand;
import com.gitblit.transport.ssh.commands.SetAccountCommand;
import com.gitblit.transport.ssh.commands.Upload;
import com.gitblit.transport.ssh.commands.VersionCommand;
import com.gitblit.utils.IdGenerator;
import com.gitblit.utils.StringUtils;
import com.gitblit.utils.WorkQueue;

import dagger.Module;
import dagger.ObjectGraph;
import dagger.Provides;

/**
 * Manager for the ssh transport. Roughly analogous to the
 * {@link com.gitblit.transport.git.GitDaemon} class.
 *
 * @author Eric Myhre
 *
 */
public class SshDaemon {

   private final Logger log = LoggerFactory.getLogger(SshDaemon.class);

   public static enum SshSessionBackend {
      MINA, NIO2
   }
	
   /**
    * 22: IANA assigned port number for ssh. Note that this is a distinct
    * concept from gitblit's default conf for ssh port -- this "default" is
    * what the git protocol itself defaults to if it sees and ssh url without a
    * port.
    */
   public static final int DEFAULT_PORT = 22;

   private static final String HOST_KEY_STORE = "sshKeyStore.pem";

   private final AtomicBoolean run;

   private final IGitblit gitblit;
   private final SshServer sshd;
   private final ObjectGraph injector;

   /**
    * Construct the Gitblit SSH daemon.
    *
    * @param gitblit
    */
   public SshDaemon(IGitblit gitblit, IdGenerator idGenerator) {
      this.gitblit = gitblit;
      this.injector = ObjectGraph.create(new SshModule());
		
      IStoredSettings settings = gitblit.getSettings();
      int port = settings.getInteger(Keys.git.sshPort, 0);
      String bindInterface = settings.getString(Keys.git.sshBindInterface,
            "localhost");

      IKeyManager keyManager = getKeyManager();

      String sshBackendStr = settings.getString(Keys.git.sshBackend,
            SshSessionBackend.NIO2.name());
      SshSessionBackend backend = SshSessionBackend.valueOf(sshBackendStr);
      System.setProperty(IoServiceFactoryFactory.class.getName(),
          backend == SshSessionBackend.MINA
             ? MinaServiceFactoryFactory.class.getName()
             : Nio2ServiceFactoryFactory.class.getName());
		
      InetSocketAddress addr;
      if (StringUtils.isEmpty(bindInterface)) {
         addr = new InetSocketAddress(port);
      } else {
         addr = new InetSocketAddress(bindInterface, port);
      }

      SshKeyAuthenticator publickeyAuthenticator = new SshKeyAuthenticator(
            keyManager, gitblit);
      sshd = SshServer.setUpDefaultServer();
      sshd.setPort(addr.getPort());
      sshd.setHost(addr.getHostName());
      sshd.setKeyPairProvider(new PEMGeneratorHostKeyProvider(new File(
            gitblit.getBaseFolder(), HOST_KEY_STORE).getPath()));
      sshd.setPublickeyAuthenticator(publickeyAuthenticator);
      sshd.setPasswordAuthenticator(new SshPasswordAuthenticator(gitblit));
      sshd.setSessionFactory(new SshSessionFactory());
      sshd.setFileSystemFactory(new DisabledFilesystemFactory());
      sshd.setTcpipForwardingFilter(new NonForwardingFilter());

      DispatchCommand gitblitCmd = new DispatchCommand();
      gitblitCmd.registerCommand(CreateRepository.class);
      gitblitCmd.registerCommand(VersionCommand.class);
      gitblitCmd.registerCommand(SetAccountCommand.class);
      gitblitCmd.registerCommand(ReviewCommand.class);

      DispatchCommand gitCmd = new DispatchCommand();
      gitCmd.registerCommand(Upload.class);
      gitCmd.registerCommand(Receive.class);

      DispatchCommand root = new DispatchCommand();
      root.registerDispatcher("gitblit", gitblitCmd);
      root.registerDispatcher("git", gitCmd);

      root.setRepositoryResolver(new RepositoryResolver<SshSession>(gitblit));
      root.setUploadPackFactory(new GitblitUploadPackFactory<SshSession>(gitblit));
      root.setReceivePackFactory(new GitblitReceivePackFactory<SshSession>(gitblit));
      root.setAuthenticator(publickeyAuthenticator);

      SshCommandFactory commandFactory = new SshCommandFactory(
            new WorkQueue(idGenerator),
            root);

      sshd.setCommandFactory(commandFactory);

      run = new AtomicBoolean(false);
   }

   public String formatUrl(String gituser, String servername, String repository) {
      if (sshd.getPort() == DEFAULT_PORT) {
         // standard port
         return MessageFormat.format("{0}@{1}/{2}", gituser, servername,
               repository);
      } else {
         // non-standard port
         return MessageFormat.format("ssh://{0}@{1}:{2,number,0}/{3}",
               gituser, servername, sshd.getPort(), repository);
      }
   }

   /**
    * Start this daemon on a background thread.
    *
    * @throws IOException
    *             the server socket could not be opened.
    * @throws IllegalStateException
    *             the daemon is already running.
    */
   public synchronized void start() throws IOException {
      if (run.get()) {
         throw new IllegalStateException(JGitText.get().daemonAlreadyRunning);
      }

      sshd.start();
      run.set(true);

      String sshBackendStr = gitblit.getSettings().getString(Keys.git.sshBackend,
            SshSessionBackend.NIO2.name());

      log.info(MessageFormat.format(
            "SSH Daemon ({0}) is listening on {1}:{2,number,0}",
            sshBackendStr, sshd.getHost(), sshd.getPort()));
   }

   /** @return true if this daemon is receiving connections. */
   public boolean isRunning() {
      return run.get();
   }

   /** Stop this daemon. */
   public synchronized void stop() {
      if (run.get()) {
         log.info("SSH Daemon stopping...");
         run.set(false);

         try {
            sshd.stop();
         } catch (InterruptedException e) {
            log.error("SSH Daemon stop interrupted", e);
         }
      }
   }
	
   protected IKeyManager getKeyManager() {
      IKeyManager keyManager = null;
      IStoredSettings settings = gitblit.getSettings();
      String clazz = settings.getString(Keys.git.sshKeysManager, FileKeyManager.class.getName());
      if (StringUtils.isEmpty(clazz)) {
         clazz = FileKeyManager.class.getName();
      }		
      try {
         Class<? extends IKeyManager> managerClass = (Class<? extends IKeyManager>) Class.forName(clazz);
         keyManager = injector.get(managerClass).start();
         if (keyManager.isReady()) {
            log.info("{} is ready.", keyManager);
         } else {
            log.warn("{} is disabled.", keyManager);
         }
      } catch (Exception e) {
         log.error("failed to create ssh key manager " + clazz, e);
         keyManager = injector.get(NullKeyManager.class).start();
      }
      return keyManager;
   }
	
   /**
    * A nested Dagger graph is used for constructor dependency injection of
    * complex classes.
    *
    * @author James Moger
    *
    */
   @Module(
         library = true,
         injects = {
               NullKeyManager.class,
               FileKeyManager.class
         }
         )
   class SshModule {

      @Provides @Singleton NullKeyManager provideNullKeyManager() {
         return new NullKeyManager();
      }
		
      @Provides @Singleton FileKeyManager provideFileKeyManager() {
         return new FileKeyManager(SshDaemon.this.gitblit);
      }
   }
}