/*
* 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.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.InetSocketAddress;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.text.MessageFormat;
import java.util.concurrent.atomic.AtomicBoolean;
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.common.keyprovider.FileKeyPairProvider;
import org.apache.sshd.common.util.SecurityUtils;
import org.bouncycastle.openssl.PEMWriter;
import org.eclipse.jgit.internal.JGitText;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.gitblit.Constants;
import com.gitblit.IStoredSettings;
import com.gitblit.Keys;
import com.gitblit.manager.IGitblit;
import com.gitblit.transport.ssh.commands.SshCommandFactory;
import com.gitblit.utils.JnaUtils;
import com.gitblit.utils.StringUtils;
import com.gitblit.utils.WorkQueue;
import com.google.common.io.Files;
/**
* Manager for the ssh transport. Roughly analogous to the
* {@link com.gitblit.transport.git.GitDaemon} class.
*
*/
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 final AtomicBoolean run;
private final IGitblit gitblit;
private final SshServer sshd;
/**
* Construct the Gitblit SSH daemon.
*
* @param gitblit
* @param workQueue
*/
public SshDaemon(IGitblit gitblit, WorkQueue workQueue) {
this.gitblit = gitblit;
IStoredSettings settings = gitblit.getSettings();
// Ensure that Bouncy Castle is our JCE provider
SecurityUtils.setRegisterBouncyCastle(true);
if (SecurityUtils.isBouncyCastleRegistered()) {
log.debug("BouncyCastle is registered as a JCE provider");
}
// Generate host RSA and DSA keypairs and create the host keypair provider
File rsaKeyStore = new File(gitblit.getBaseFolder(), "ssh-rsa-hostkey.pem");
File dsaKeyStore = new File(gitblit.getBaseFolder(), "ssh-dsa-hostkey.pem");
generateKeyPair(rsaKeyStore, "RSA", 2048);
generateKeyPair(dsaKeyStore, "DSA", 0);
FileKeyPairProvider hostKeyPairProvider = new FileKeyPairProvider();
hostKeyPairProvider.setFiles(new String [] { rsaKeyStore.getPath(), dsaKeyStore.getPath(), dsaKeyStore.getPath() });
// Client public key authenticator
CachingPublicKeyAuthenticator keyAuthenticator =
new CachingPublicKeyAuthenticator(gitblit.getPublicKeyManager(), gitblit);
// Configure the preferred SSHD backend
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());
// Create the socket address for binding the SSH server
int port = settings.getInteger(Keys.git.sshPort, 0);
String bindInterface = settings.getString(Keys.git.sshBindInterface, "");
InetSocketAddress addr;
if (StringUtils.isEmpty(bindInterface)) {
addr = new InetSocketAddress(port);
} else {
addr = new InetSocketAddress(bindInterface, port);
}
// Create the SSH server
sshd = SshServer.setUpDefaultServer();
sshd.setPort(addr.getPort());
sshd.setHost(addr.getHostName());
sshd.setKeyPairProvider(hostKeyPairProvider);
sshd.setPublickeyAuthenticator(keyAuthenticator);
sshd.setPasswordAuthenticator(new UsernamePasswordAuthenticator(gitblit));
sshd.setSessionFactory(new SshServerSessionFactory());
sshd.setFileSystemFactory(new DisabledFilesystemFactory());
sshd.setTcpipForwardingFilter(new NonForwardingFilter());
sshd.setCommandFactory(new SshCommandFactory(gitblit, workQueue));
sshd.setShellFactory(new WelcomeShell(settings));
// Set the server id. This can be queried with:
// ssh-keyscan -t rsa,dsa -p 29418 localhost
String version = String.format("%s (%s-%s)", Constants.getGitBlitVersion().replace(' ', '_'),
sshd.getVersion(), sshBackendStr);
sshd.getProperties().put(SshServer.SERVER_IDENTIFICATION, version);
run = new AtomicBoolean(false);
}
public String formatUrl(String gituser, String servername, String repository) {
if (sshd.getPort() == DEFAULT_PORT) {
// standard port
return MessageFormat.format("ssh://{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 {
((SshCommandFactory) sshd.getCommandFactory()).stop();
sshd.stop();
} catch (InterruptedException e) {
log.error("SSH Daemon stop interrupted", e);
}
}
}
private void generateKeyPair(File file, String algorithm, int keySize) {
if (file.exists()) {
return;
}
try {
KeyPairGenerator generator = SecurityUtils.getKeyPairGenerator(algorithm);
if (keySize != 0) {
generator.initialize(keySize);
log.info("Generating {}-{} SSH host keypair...", algorithm, keySize);
} else {
log.info("Generating {} SSH host keypair...", algorithm);
}
KeyPair kp = generator.generateKeyPair();
// create an empty file and set the permissions
Files.touch(file);
try {
JnaUtils.setFilemode(file, JnaUtils.S_IRUSR | JnaUtils.S_IWUSR);
} catch (UnsatisfiedLinkError | UnsupportedOperationException e) {
// Unexpected/Unsupported OS or Architecture
}
FileOutputStream os = new FileOutputStream(file);
PEMWriter w = new PEMWriter(new OutputStreamWriter(os));
w.writeObject(kp);
w.flush();
w.close();
} catch (Exception e) {
log.warn(MessageFormat.format("Unable to generate {0} keypair", algorithm), e);
return;
}
}
}