Question

使用Apache FTPSClient listFiles（String）....

在恢复SSL会话，然后从Apache FTPSClient代码调用sslSocketImpl.startHandshake（）之后，aplication有时会崩溃。

我设置javax.net.debug来打印ssl信息...... System.setProperty（“javax.net.debug”，“all”）;

这就是我得到的。

%% Client cached [Session-3, SSL_RSA_WITH_3DES_EDE_CBC_SHA]
%% Try resuming [Session-3, SSL_RSA_WITH_3DES_EDE_CBC_SHA] from port 4149
*** ClientHello, TLSv1
....
main, received EOFException: error
main, handling exception: javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake
main, SEND TLSv1 ALERT:  fatal, description = handshake_failure
main, WRITE: TLSv1 Alert, length = 2
[Raw write]: length = 7
0000: 15 03 01 00 02 02 28                               ......(
main, called closeSocket()
[Mon Aug 30 17:41:52 PDT 2010][class com.smgtec.sff.fileupload.poller.BasicFTPAccess] - Could not list directory: sqjavax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake
 at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:808)
 at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1096)
 at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1123)
 at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1107)
 at com.smgtec.sff.fileupload.poller.FixedFTPSClient._openDataConnection_(FixedFTPSClient.java:525)
 at org.apache.commons.net.ftp.FTPClient.initiateListParsing(FTPClient.java:2296)
 at org.apache.commons.net.ftp.FTPClient.initiateListParsing(FTPClient.java:2269)

Padded plaintext before ENCRYPTION:  len = 32
0000: 50 41  at org.apache.commons.net.ftp.FTPClient.listFiles(FTPClient.java:2046)
 at com.smgtec.sff.fileupload.poller.BasicFTPAccess.listFiles(BasicFTPAccess.java:100)
 at com.smgtec.sff.fileupload.poller.FTPPoller.addFileForProcessing(FTPPoller.java:67)
 at com.smgtec.sff.fileupload.poller.FTPPoller.main(FTPPoller.java:385)
Caused by: java.io.EOFException: SSL peer shut down incorrectly
 at com.sun.net.ssl.internal.ssl.InputRecord.read(InputRecord.java:333)
 at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:789)
 ... 10 more

我们这里也有jscape FTPS客户端，它会产生同样的问题。

Answer 1

我建议你在FTPPoller中加入一些重试逻辑 - 看起来主机正在关闭连接而不是你的代码。我们曾经看到偶尔通过远程主机错误关闭连接，这些错误最好通过简单的重试来处理。

Answer 2

我使用SSLSession.invalidate（）这样解决了它现在似乎工作了......虽然我们不再使用FTPS了。如果这是一个真正的解决方案，那么Apache commons-net FTPSClient或我们连接的FTP服务器就会出现问题。

ftp = new FTPSClient() 
      {
        private Socket socket;

        protected Socket _openDataConnection_(int command, String arg) throws IOException
        {
          if (socket != null && socket instanceof SSLSocket)
          {
            // We have problems resuming cached SSL Sessions. Exceptions are
            // thrown and the system crashes... So we invalidate each SSL
            // session we used last.
            SSLSocket sslSocket = (SSLSocket) socket;
            sslSocket.getSession().invalidate();
          }
          socket = super._openDataConnection_(command, arg);
          return socket;
        }
      };

BTW我相信我们正在连接到FileZilla FTP服务器。我怀疑这个修复程序会导致更多的网络聊天来回传递密钥/证书等等。

SSLSocketImpl.startHandshake（）在恢复缓存的会话时抛出SSLHanshakeException / EOFException

2 个答案: