SSH library for Java
Update: The GSOC project and the code there isn't active, but this is: https://github.com/hierynomus/sshj
hierynomus took over as maintainer since early 2015. Here is the older, no longer maintained, Github link:
https://github.com/shikhar/sshj
There was a GSOC project:
http://code.google.com/p/commons-net-ssh/
Code quality seem to be better than JSch, which, while a complete and working implementation, lacks documentation. Project page spots an upcoming beta release, last commit to the repository was mid-august.
Compare the APIs:
http://code.google.com/p/commons-net-ssh/
SSHClient ssh = new SSHClient();
//ssh.useCompression();
ssh.loadKnownHosts();
ssh.connect("localhost");
try {
ssh.authPublickey(System.getProperty("user.name"));
new SCPDownloadClient(ssh).copy("ten", "/tmp");
} finally {
ssh.disconnect();
}
http://www.jcraft.com/jsch/
Session session = null;
Channel channel = null;
try {
JSch jsch = new JSch();
session = jsch.getSession(username, host, 22);
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.setPassword(password);
session.connect();
// exec 'scp -f rfile' remotely
String command = "scp -f " + remoteFilename;
channel = session.openChannel("exec");
((ChannelExec) channel).setCommand(command);
// get I/O streams for remote scp
OutputStream out = channel.getOutputStream();
InputStream in = channel.getInputStream();
channel.connect();
byte[] buf = new byte[1024];
// send '\0'
buf[0] = 0;
out.write(buf, 0, 1);
out.flush();
while (true) {
int c = checkAck(in);
if (c != 'C') {
break;
}
// read '0644 '
in.read(buf, 0, 5);
long filesize = 0L;
while (true) {
if (in.read(buf, 0, 1) < 0) {
// error
break;
}
if (buf[0] == ' ') {
break;
}
filesize = filesize * 10L + (long) (buf[0] - '0');
}
String file = null;
for (int i = 0;; i++) {
in.read(buf, i, 1);
if (buf[i] == (byte) 0x0a) {
file = new String(buf, 0, i);
break;
}
}
// send '\0'
buf[0] = 0;
out.write(buf, 0, 1);
out.flush();
// read a content of lfile
FileOutputStream fos = null;
fos = new FileOutputStream(localFilename);
int foo;
while (true) {
if (buf.length < filesize) {
foo = buf.length;
} else {
foo = (int) filesize;
}
foo = in.read(buf, 0, foo);
if (foo < 0) {
// error
break;
}
fos.write(buf, 0, foo);
filesize -= foo;
if (filesize == 0L) {
break;
}
}
fos.close();
fos = null;
if (checkAck(in) != 0) {
System.exit(0);
}
// send '\0'
buf[0] = 0;
out.write(buf, 0, 1);
out.flush();
channel.disconnect();
session.disconnect();
}
} catch (JSchException jsche) {
System.err.println(jsche.getLocalizedMessage());
} catch (IOException ioe) {
System.err.println(ioe.getLocalizedMessage());
} finally {
channel.disconnect();
session.disconnect();
}
}
I just discovered sshj, which seems to have a much more concise API than JSCH (but it requires Java 6). The documentation is mostly by examples-in-the-repo at this point, and usually that's enough for me to look elsewhere, but it seems good enough for me to give it a shot on a project I just started.
Take a look at the very recently released SSHD, which is based on the Apache MINA project.
The Java Secure Channel (JSCH) is a very popular library, used by maven, ant and eclipse. It is open source with a BSD style license.