我无法使用具有自定义SSLContext的Apache FTPSClient通过FTPS连接到FTP服务器-获取“无法识别的SSL消息，纯文本连接？”

Question

我正在编写程序以通过FTPS连接到FTP服务器。

源代码：

String protocol = "TLS";
String host = "192.168.5.165";
String username = "usr";
String password = "111";
String trustStorePath = "C:/TEMP/truststore";
String trustStorePassword = "111111";
int port = 990;

FTPSClient client = new FTPSClient(protocol);

KeyStore trustStore = loadStore("JKS", new File(trustStorePath), trustStorePassword);
X509TrustManager trustManager = TrustManagerUtils.getDefaultTrustManager(trustStore);

SSLContext ctx = SSLContext.getInstance("TLSv1.1");
ctx.init(null, new TrustManager[] {trustManager}, null);

FTPSSocketFactory socketFactory = new FTPSSocketFactory(ctx);
client.setSocketFactory(socketFactory);

client.addProtocolCommandListener(new PrintCommandListener(new 
PrintWriter(System.out)));
client.connect(host, port);

我将服务器的证书导入了trustStore 。 但是运行此代码后，我得到此错误：

220 Wing FTP Server ready... (UNREGISTERED WING FTP SERVER)
AUTH TLS
234 AUTH command OK. Initializing TLS connection.

javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?

  at sun.security.ssl.InputRecord.handleUnknownRecord(InputRecord.java:710)
  at sun.security.ssl.InputRecord.read(InputRecord.java:527)
  at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:973)
  at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
  at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
  at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
  at org.apache.commons.net.ftp.FTPSClient.sslNegotiation(FTPSClient.java:269)
  at org.apache.commons.net.ftp.FTPSClient._connectAction_(FTPSClient.java:211)
  at org.apache.commons.net.SocketClient.connect(SocketClient.java:183)
  at org.apache.commons.net.SocketClient.connect(SocketClient.java:203)
  at edtesb.remsenergy.FTPSTest.test(FTPSTest.java:63)

我做错了什么？

Answer 1

在我看来，您已经对其进行了过度设计。

我不确定我是否能完全理解您的代码做什么，但是我相信您无意间对连接进行了双重加密。

---

如果您确实要连接到隐式FTPS端口990，请使用

FTPSClient client = new FTPSClient(protocol, true);

或默认为protocol="TLS" ，这也可以做到：

FTPSClient client = new FTPSClient(true);

client.connect(host); // 990 is default, with FTPSClient with isImplicit=true

---

尽管隐式FTPS已过时，但最好通过连接默认的FTP端口21使用显式FTPS（如果服务器支持，大多数情况下）：

FTPSClient client = new FTPSClient();

client.connect(host);

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如果需要自定义SSLContext ，只需使用相应的FTPSClient重载，例如：

FTPSClient client = new FTPSClient(ctx);

client.connect(host);