Revise SSH public key integration with AuthenticationManager

James Moger

2014-03-14 44e2ee1d05a9d455ae60dd64058b31f006d551b7

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

@@ -18,82 +18,56 @@
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 javax.inject.Singleton;

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.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.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.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.git.GitDaemon} class.
 * 
 * {@link com.gitblit.transport.git.GitDaemon} class.
 *
 * @author Eric Myhre
 * 
 *
 */
public class SshDaemon extends SshServer {
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
@@ -104,91 +78,99 @@

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

   private InetSocketAddress myAddress;
   private final AtomicBoolean run;

   private AtomicBoolean run;

   @SuppressWarnings("unused")
   private IGitblit gitblit;
   private final IGitblit gitblit;
   private final SshServer sshd;
   private final ObjectGraph injector;

   /**
    * Construct the Gitblit SSH daemon.
    * 
    *
    * @param gitblit
    */
   @Inject
   SshDaemon(IGitblit gitblit, IdGenerator idGenerator,
         SshCommandFactory factory) {
   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)) {
         myAddress = new InetSocketAddress(port);
         addr = new InetSocketAddress(port);
      } else {
         myAddress = new InetSocketAddress(bindInterface, port);
         addr = new InetSocketAddress(bindInterface, port);
      }

      setPort(myAddress.getPort());
      setHost(myAddress.getHostName());
      setup();
      setKeyPairProvider(new PEMGeneratorHostKeyProvider(new File(
      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()));
      setPublickeyAuthenticator(new SshKeyAuthenticator(gitblit));
      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);
      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) {
      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, getPort(), repository);
               gituser, servername, sshd.getPort(), repository);
      }
   }

   /**
    * Start this daemon on a background thread.
    * 
    *
    * @throws IOException
    *             the server socket could not be opened.
    * @throws IllegalStateException
@@ -199,12 +181,15 @@
         throw new IllegalStateException(JGitText.get().daemonAlreadyRunning);
      }

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

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

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

   /** @return true if this daemon is receiving connections. */
@@ -219,117 +204,57 @@
         run.set(false);

         try {
            super.stop();
            sshd.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;
               }
            };
	
   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);
         }
      });

      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();
         }
      } catch (Exception e) {
         log.error("failed to create ssh key manager " + clazz, e);
         keyManager = injector.get(NullKeyManager.class).start();
      }
      setCipherFactories(avail);
      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);
      }
   }
}