使用SSL连接Apache FtpServer时出错

Question

I'm trying to set up a simple test FTP server using Apache FtpServer, and I'm having trouble configuring to use SSL.

Following the Apache FtpServer documentation , here is what my code looks like so far:

        FtpServerFactory ftpServerFactory = new FtpServerFactory();
        ListenerFactory listenerFactory = new ListenerFactory();
        listenerFactory.setPort(990);
        listenerFactory.setServerAddress("example.com");

        SslConfigurationFactory sslConfigurationFactory = new SslConfigurationFactory();
        sslConfigurationFactory.setKeystoreFile(JKS);
        sslConfigurationFactory.setKeystorePassword(JKS_PASS);
        listenerFactory.setSslConfiguration(sslConfigurationFactory.createSslConfiguration());
        listenerFactory.setImplicitSsl(true);

        ftpServerFactory.addListener("default", listenerFactory.createListener());

        PropertiesUserManagerFactory userManagerFactory = new PropertiesUserManagerFactory();
        userManagerFactory.setFile(USERS_PATH.toFile());

        BaseUser test = new BaseUser();
        sample1.setName("test");
        sample1.setPassword("test");
        sample1.setHomeDirectory(HOME.getAbsolutePath().toString());
        test.setAuthorities(List.of(new WritePermission());

        UserManager userManager = userManagerFactory.createUserManager();
        try {
            userManager.save(test);
        }
        catch (FtpException e) {
            e.printStackTrace();
        }

        ftpServerFactory.setUserManager(userManager);

        FtpServer server = ftpServerFactory.createServer();
        try {
            server.start();
        }
        catch (FtpException e) {
            e.printStackTrace();
        }

When I try to connect to the FTPS server, I get this error from the server:

[main] INFO org.apache.ftpserver.impl.DefaultFtpServer - FTP server started
[NioProcessor-1] WARN org.apache.mina.util.DefaultExceptionMonitor - Unexpected exception.
org.apache.mina.core.filterchain.IoFilterLifeCycleException: onPreAdd(): sslFilter:SslFilter in (0x00000002: nio socket, server, /2.51.214.102:50475 => /142.93.208.41:990)
    at org.apache.mina.core.filterchain.DefaultIoFilterChain.register(DefaultIoFilterChain.java:465)
    at org.apache.mina.core.filterchain.DefaultIoFilterChain.addLast(DefaultIoFilterChain.java:234)
    at org.apache.mina.core.filterchain.DefaultIoFilterChainBuilder.buildFilterChain(DefaultIoFilterChainBuilder.java:553)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.addNow(AbstractPollingIoProcessor.java:832)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.handleNewSessions(AbstractPollingIoProcessor.java:752)
    at org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run(AbstractPollingIoProcessor.java:652)
    at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: java.lang.IllegalArgumentException: Unsupported protocolTLS
    at java.base/sun.security.ssl.ProtocolVersion.namesOf(ProtocolVersion.java:292)
    at java.base/sun.security.ssl.SSLEngineImpl.setEnabledProtocols(SSLEngineImpl.java:798)
    at org.apache.mina.filter.ssl.SslHandler.init(SslHandler.java:184)
    at org.apache.mina.filter.ssl.SslFilter.onPreAdd(SslFilter.java:458)
    at org.apache.mina.core.filterchain.DefaultIoFilterChain.register(DefaultIoFilterChain.java:463)
    ... 9 more

From my client (FileZilla), I get this error:

Status:         Resolving address of itgsiatest.duss.app
Status:         Connecting to 142.93.208.41:990...
Status:         Connection established, initializing TLS...
Status:         Connection attempt failed with "ECONNRESET - Connection reset by peer".
Error:          Could not connect to server

Is there anything I missed?

Answer 1

You are going into not documented waters.

1. I assume you have managed to setup the FTP server without encryption standalone .
2. I assume you have managed to set the FTP server with encryption standalone .
3. I assume you have managed to setup the FTP server without encryption embedded .
4. Now you are trying to combine encryption and embedding . It means you need to apply all the configuration changes differing between steps 1 and 2 via code added to step 3.