Net::FTPSSL在命令通道[0] (0，1) ()行…上出现意外的EOF错误

Question

我试图在ubuntu服务器上使用Perl和Net::FTPSSL将本地文件上传到外部托管的Net服务器。使用TLS登录可以正常工作，但是当尝试ls远程服务器上的文件时，它会失败。错误是“命令通道0 ()在…行上的意外EOF”。

如果使用put或get试图发送/获取文件，则会得到相同的错误。但是，如果我尝试交互地使用普通的unix客户端，它可以正常工作。

知道我该怎么解决吗？

更新21-5-2020-我更新了代码和输出文件，在下面提供了更多的调试日志记录。

代码非常简单。如下所示：

#!/usr/bin/perl
use strict;
use IO::Socket::SSL;
use Net::FTPSSL;

$IO::Socket::SSL::DEBUG = 3;
$Net::SSLeay::trace = 4;

my $file=$ARGV[0];
my $dir=$ARGV[1];

#----------------------------------------------------------------------
#1st try
if (1) {
    #print "$server $username $password\n";
    my $server="hubble.krystal.co.uk";
    my $fields = `cat nickdata`;
    chomp($fields);
    my ($username, $password) = split /\t/, $fields;
    my $rc;

    open (STDERR, ">FTPLog.txt");

    my $ftp = Net::FTPSSL->new($server,
              Encryption => EXP_CRYPT,
              Debug => 1,
              OverrideHELP => 0,
              Croak => 1);
    $ftp->trapWarn();

    $ftp->login($username, $password) || die "Cannot login\n";

    $ftp->pwd;

    $ftp->feat();
    $ftp->noop();
    $ftp->supported("MLSD");
    $ftp->supported("NLST");
    $ftp->quot("OPTS", "UTF8 ON");
    $ftp->quot("TYPE", "I");
    $ftp->quot("SYST");

    #these fail
    #$ftp->nlst();
    $ftp->list();
    exit;
}

日志文件现在包括SSL调试日志记录如下：

Net-FTPSSL Version: 0.42
IO-Socket-SSL Version: 2.068
Net-SSLeay Version: 1.84
IO-Socket-INET Version: 1.41
IO-Socket-INET6 might not be installed.
IO-Socket-IP Version: 0.39
IO Version: 1.42
Socket Version: 2.029

IPv6 support available via IO::Socket::IP (0.39)  Key: (Family)

Perl: 5.026001  [5.26.1],  OS: linux

***** IPv6 not yet supported in Net::FTPSSL! *****

Server (port): hubble.krystal.co.uk (21)

Keys: (OverrideHELP), (Encryption), (Debug), (Croak)
Values: (0), (E), (1), (1)

SKT <<< 220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
SKT <<< 220-You are user number 1 of 50 allowed.
SKT <<< 220-Local time is now 19:54. Server port: 21.
SKT <<< 220-This is a private system - No anonymous login
SKT <<< 220-IPv6 connections are also welcome on this server.
SKT <<< 220 You will be disconnected after 15 minutes of inactivity.
SKT >>> AUTH TLS
SKT <<< 234 AUTH TLS OK.
DEBUG: .../IO/Socket/SSL.pm:3010: new ctx 94714584143456
DEBUG: .../IO/Socket/SSL.pm:1620: start handshake
DEBUG: .../IO/Socket/SSL.pm:1177: global error: Undefined SSL object
DEBUG: .../IO/Socket/SSL.pm:787: ssl handshake not started
DEBUG: .../IO/Socket/SSL.pm:829: using SNI with hostname hubble.krystal.co.uk
DEBUG: .../IO/Socket/SSL.pm:880: set socket to non-blocking to enforce timeout=120
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> -1
DEBUG: .../IO/Socket/SSL.pm:907: ssl handshake in progress
DEBUG: .../IO/Socket/SSL.pm:917: waiting for fd to become ready: SSL wants a read first
DEBUG: .../IO/Socket/SSL.pm:937: socket ready, retrying connect
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> -1
DEBUG: .../IO/Socket/SSL.pm:907: ssl handshake in progress
DEBUG: .../IO/Socket/SSL.pm:917: waiting for fd to become ready: SSL wants a read first
DEBUG: .../IO/Socket/SSL.pm:937: socket ready, retrying connect
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> -1
DEBUG: .../IO/Socket/SSL.pm:907: ssl handshake in progress
DEBUG: .../IO/Socket/SSL.pm:917: waiting for fd to become ready: SSL wants a read first
DEBUG: .../IO/Socket/SSL.pm:937: socket ready, retrying connect
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> -1
DEBUG: .../IO/Socket/SSL.pm:907: ssl handshake in progress
DEBUG: .../IO/Socket/SSL.pm:917: waiting for fd to become ready: SSL wants a read first
DEBUG: .../IO/Socket/SSL.pm:937: socket ready, retrying connect
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> -1
DEBUG: .../IO/Socket/SSL.pm:907: ssl handshake in progress
DEBUG: .../IO/Socket/SSL.pm:917: waiting for fd to become ready: SSL wants a read first
DEBUG: .../IO/Socket/SSL.pm:937: socket ready, retrying connect
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> 1
DEBUG: .../IO/Socket/SSL.pm:952: ssl handshake done

Object HASH Details ... (SSL:arguments - E)
  SSL_hostname ==> hubble.krystal.co.uk
  SSL_verify_mode ==> 0
  SSL_version ==> TLSv12
  Timeout ==> 120


Object Net::FTPSSL Details ... (hubble.krystal.co.uk:21 - E)
  _FTPSSL_arguments ==> HASH(0x562475877a30)
      -- Croak ===> 1
      -- Crypt ===> E
      -- FixGetTs ===> 0
      -- FixPutTs ===> 0
      -- Host ===> hubble.krystal.co.uk
      -- OverrideHELP ===> 0
      -- Pret ===> 0
      -- Timeout ===> 120
      -- buf_size ===> 10240
      -- data_prot ===> P
      -- dcsc_mode ===> 1
      -- debug ===> 1
      -- debug_extra ===> 0
      -- debug_no_help ===> 0
      -- help_cmds_found ===> HASH(0x5624758b7740)
      -- help_cmds_msg ===> 214 HELP Command Overridden by request.
      -- help_cmds_no_syntax_available ===> 1
      -- last_ftp_msg ===> 234 AUTH TLS OK.
      -- myContext ===> HASH(0x5624758b7b18)
          -- SSL_reuse_ctx ----> IO::Socket::SSL::SSL_Context=HASH(0x562475b19828)
              -- context ++++> 94714584143456
              -- ocsp_cache ++++> (undef)
              -- ocsp_mode ++++> 0
              -- verify_mode ++++> 0
      -- mySocketOpts ===> HASH(0x562475384650)
          -- PeerAddr ----> hubble.krystal.co.uk
          -- PeerPort ----> 21
          -- Proto ----> tcp
          -- Timeout ----> 120
      -- start_SSL_opts ===> HASH(0x5624758775e0)
          -- SSL_hostname ----> hubble.krystal.co.uk
          -- SSL_verify_mode ----> 0
          -- SSL_version ----> TLSv12
          -- Timeout ----> 120
      -- trace ===> 0
      -- type ===> A
  _SSL_arguments ==> HASH(0x562475b198b8)
      -- PeerAddr ===> 77.72.1.20
      -- PeerPort ===> 21
      -- Proto ===> tcp
      -- SSL_check_crl ===> 0
      -- SSL_cipher_list ===> ECDHE-ECDSA-AES128-GCM-SHA256 ECDHE-RSA-AES128-GCM-SHA256 DHE-RSA-AES128-GCM-SHA256 ECDHE-ECDSA-CHACHA20-POLY1305 ECDHE-RSA-CHACHA20-POLY1305 ECDHE-ECDSA-AES256-SHA ECDHE-RSA-AES256-SHA DHE-RSA-AES256-SHA ECDHE-ECDSA-AES128-SHA ECDHE-RSA-AES128-SHA DHE-RSA-AES128-SHA AES128-GCM-SHA256 AES256-SHA AES128-SHA DES-CBC3-SHA ECDHE-RSA-AES256-GCM-SHA384 ECDHE-ECDSA-AES256-GCM-SHA384 AES256-SHA256 DHE-DSS-AES256-SHA256 DHE-DSS-AES256-SHA DHE-DSS-AES128-SHA EDH-DSS-DES-CBC3-SHA !EXP !MEDIUM !LOW !eNULL !aNULL !RC4 !DES !MD5 !PSK !SRP
      -- SSL_hostname ===> hubble.krystal.co.uk
      -- SSL_server ===> 0
      -- SSL_use_cert ===> 0
      -- SSL_verify_mode ===> 0
      -- SSL_version ===> TLSv12
  _SSL_ctx ==> IO::Socket::SSL::SSL_Context=HASH(0x562475b19828)
      -- context ===> 94714584143456
      -- ocsp_cache ===> (undef)
      -- ocsp_mode ===> 0
      -- verify_mode ===> 0
  _SSL_fileno ==> 3
  _SSL_ioclass_upgraded ==> IO::Socket::INET
  _SSL_last_err ==> ARRAY(0x562475afdca0)
      [SSL wants a read first, 4]
  _SSL_object ==> 94714593482576
  _SSL_opened ==> 1
  io_socket_domain ==> 2
  io_socket_proto ==> 6
  io_socket_timeout ==> 120
  io_socket_type ==> 1
************************************************************
>>> USER +++++++
<<< 331 User <++++++> OK. Password required
>>> PASS *******
<<< 230 OK. Current restricted directory is /
<<+ 503 Unsupported command HELP.
>>> PWD
<<< 257 "/" is your current location
>>> FEAT
<<< 211-Extensions supported:
<<<  EPRT
<<<  IDLE
<<<  MDTM
<<<  SIZE
<<<  MFMT
<<<  REST STREAM
<<<  MLST type*;size*;sizd*;modify*;UNIX.mode*;UNIX.uid*;UNIX.gid*;unique*;
<<<  MLSD
<<<  AUTH TLS
<<<  PBSZ
<<<  PROT
<<<  UTF8
<<<  TVFS
<<<  ESTA
<<<  PASV
<<<  EPSV
<<<  SPSV
<<<  ESTP
<<< 211 End.
<<+ 111 Auto-adding OPTS Command!
>>> NOOP
<<< 200 Zzz...
<<+ 502 Unknown command MLSD.
<<+ 502 Unknown command NLST.
>>> OPTS UTF8 ON
<<< 200 OK, UTF-8 enabled
>>> TYPE I
<<< 200 TYPE is now 8-bit binary
>>> SYST
<<< 215 UNIX Type: L8
>>> PBSZ 0
<<< 200 PBSZ=0
>>> PROT P
<<< 200 Data protection level set to "private"
>>> PASV
<<< 227 Entering Passive Mode (77,72,1,20,213,32)
--- Host (77.72.1.20)  Port (54560)
>>> LIST
<<< 150 Accepted data connection
DEBUG: .../IO/Socket/SSL.pm:1620: start handshake
DEBUG: .../IO/Socket/SSL.pm:1177: global error: Undefined SSL object
DEBUG: .../IO/Socket/SSL.pm:787: ssl handshake not started
DEBUG: .../IO/Socket/SSL.pm:829: using SNI with hostname 77.72.1.20
DEBUG: .../IO/Socket/SSL.pm:894: call Net::SSLeay::connect
DEBUG: .../IO/Socket/SSL.pm:897: done Net::SSLeay::connect -> 1
DEBUG: .../IO/Socket/SSL.pm:952: ssl handshake done
Unexpected EOF on Command Channel [0] (0, 1) ()
 at ./nickFTPTest.pl line 45.
DEBUG: .../IO/Socket/SSL.pm:3059: free ctx 94714584143456 open=94714584143456
DEBUG: .../IO/Socket/SSL.pm:3070: OK free ctx 94714584143456

更新2，21-5-2020:我添加了附加到同一个FileZilla服务器的FileZilla跟踪的副本。FileZilla成功了，但是当我尝试使用FTPSSL复制相同的命令时，它就失败了。

Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 0
Status: Resolving address of <server>
Status: Connecting to 77.72.1.20:21...
Status: Connection established, waiting for welcome message...
Trace:  CFtpControlSocket::OnReceive()
Response:   220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
Response:   220-You are user number 2 of 50 allowed.
Response:   220-Local time is now 20:09. Server port: 21.
Response:   220-This is a private system - No anonymous login
Response:   220-IPv6 connections are also welcome on this server.
Response:   220 You will be disconnected after 15 minutes of inactivity.
Trace:  CFtpLogonOpData::ParseResponse() in state 1
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 2
Command:    AUTH TLS
Trace:  CFtpControlSocket::OnReceive()
Response:   234 AUTH TLS OK.
Trace:  CFtpLogonOpData::ParseResponse() in state 2
Status: Initializing TLS...
Trace:  tls_layer_impl::client_handshake()
Trace:  tls_layer_impl::continue_handshake()
Trace:  TLS handshake: About to send CLIENT HELLO
Trace:  TLS handshake: Sent CLIENT HELLO
Trace:  tls_layer_impl::on_send()
Trace:  tls_layer_impl::continue_handshake()
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  TLS handshake: Received SERVER HELLO
Trace:  TLS handshake: Processed SERVER HELLO
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  TLS handshake: Received CERTIFICATE
Trace:  TLS handshake: Processed CERTIFICATE
Trace:  TLS handshake: Received SERVER KEY EXCHANGE
Trace:  TLS handshake: Processed SERVER KEY EXCHANGE
Trace:  TLS handshake: Received SERVER HELLO DONE
Trace:  TLS handshake: Processed SERVER HELLO DONE
Trace:  TLS handshake: About to send CLIENT KEY EXCHANGE
Trace:  TLS handshake: Sent CLIENT KEY EXCHANGE
Trace:  TLS handshake: About to send FINISHED
Trace:  TLS handshake: Sent FINISHED
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  TLS handshake: Received NEW SESSION TICKET
Trace:  TLS handshake: Processed NEW SESSION TICKET
Trace:  TLS handshake: Received FINISHED
Trace:  TLS handshake: Processed FINISHED
Trace:  TLS Handshake successful
Trace:  Protocol: TLS1.2, Key exchange: ECDHE-SECP256R1-RSA-SHA512, Cipher: AES-256-GCM, MAC: AEAD
Trace:  tls_layer_impl::verify_certificate()
Trace:  Hostname does not match certificate SANs
Status: Verifying certificate...
Trace:  CFtpControlSocket::SetAsyncRequestReply
Status: TLS connection established.
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 6
Command:    USER <user>
Trace:  CFtpControlSocket::OnReceive()
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   331 User <user> OK. Password required
Trace:  CFtpLogonOpData::ParseResponse() in state 6
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 6
Command:    PASS ********************
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   230 OK. Current restricted directory is /
Trace:  CFtpLogonOpData::ParseResponse() in state 6
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 7
Command:    SYST
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   215 UNIX Type: L8
Trace:  CFtpLogonOpData::ParseResponse() in state 7
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 8
Command:    FEAT
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   211-Extensions supported:
Response:    EPRT
Response:    IDLE
Response:    MDTM
Response:    SIZE
Response:    MFMT
Response:    REST STREAM
Response:    MLST type*;size*;sizd*;modify*;UNIX.mode*;UNIX.uid*;UNIX.gid*;unique*;
Response:    MLSD
Response:    AUTH TLS
Response:    PBSZ
Response:    PROT
Response:    UTF8
Response:    TVFS
Response:    ESTA
Response:    PASV
Response:    EPSV
Response:    SPSV
Response:    ESTP
Response:   211 End.
Trace:  CFtpLogonOpData::ParseResponse() in state 8
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 10
Command:    OPTS UTF8 ON
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   200 OK, UTF-8 enabled
Trace:  CFtpLogonOpData::ParseResponse() in state 10
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 11
Command:    PBSZ 0
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   200 PBSZ=0
Trace:  CFtpLogonOpData::ParseResponse() in state 11
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpLogonOpData::Send() in state 12
Command:    PROT P
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   200 Data protection level set to "private"
Trace:  CFtpLogonOpData::ParseResponse() in state 12
Status: Logged in
Trace:  Measured latency of 17 ms
Trace:  CFtpControlSocket::ResetOperation(0)
Trace:  CControlSocket::ResetOperation(0)
Trace:  CFtpLogonOpData::Reset(0) in state 15
Trace:  CFileZillaEnginePrivate::ResetOperation(0)
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpListOpData::Send() in state 0
Status: Retrieving directory listing...
Trace:  CFtpChangeDirOpData::Send() in state 0
Trace:  CFtpChangeDirOpData::Send() in state 1
Command:    PWD
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   257 "/" is your current location
Trace:  CFtpChangeDirOpData::ParseResponse() in state 1
Trace:  CFtpControlSocket::ResetOperation(0)
Trace:  CControlSocket::ResetOperation(0)
Trace:  CFtpChangeDirOpData::Reset(0) in state 1
Trace:  CFtpListOpData::SubcommandResult(0) in state 1
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpListOpData::Send() in state 2
Trace:  CFtpRawTransferOpData::Send() in state 0
Trace:  CFtpRawTransferOpData::Send() in state 1
Command:    TYPE I
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   200 TYPE is now 8-bit binary
Trace:  CFtpRawTransferOpData::ParseResponse() in state 1
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpRawTransferOpData::Send() in state 2
Command:    PASV
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   227 Entering Passive Mode (77,72,1,20,207,20)
Trace:  CFtpRawTransferOpData::ParseResponse() in state 2
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpRawTransferOpData::Send() in state 4
Trace:  Binding data connection source IP to control connection source IP 192.168.1.34
Trace:  tls_layer_impl::client_handshake()
Trace:  Trying to resume existing TLS session.
Command:    MLSD
Trace:  tls_layer_impl::on_send()
Trace:  tls_layer_impl::continue_handshake()
Trace:  TLS handshake: About to send CLIENT HELLO
Trace:  TLS handshake: Sent CLIENT HELLO
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   150 Accepted data connection
Trace:  CFtpRawTransferOpData::ParseResponse() in state 4
Trace:  CControlSocket::SendNextCommand()
Trace:  CFtpRawTransferOpData::Send() in state 5
Trace:  tls_layer_impl::on_read()
Trace:  tls_layer_impl::continue_handshake()
Trace:  TLS handshake: Received SERVER HELLO
Trace:  TLS handshake: Processed SERVER HELLO
Trace:  TLS handshake: Received FINISHED
Trace:  TLS handshake: Processed FINISHED
Trace:  TLS handshake: About to send FINISHED
Trace:  TLS handshake: Sent FINISHED
Trace:  TLS Handshake successful
Trace:  TLS Session resumed
Trace:  Protocol: TLS1.2, Key exchange: ECDHE-SECP256R1, Cipher: AES-256-GCM, MAC: AEAD
Trace:  tls_layer_impl::verify_certificate()
Trace:  CTransferSocket::OnConnect
Trace:  CTransferSocket::OnReceive(), m_transferMode=0
Trace:  tls_layer_impl::on_read()
Trace:  CTransferSocket::OnReceive(), m_transferMode=0
Trace:  tls_layer_impl::on_read()
Trace:  CTransferSocket::OnReceive(), m_transferMode=0
Trace:  tls_layer_impl::on_read()
Trace:  CTransferSocket::OnReceive(), m_transferMode=0
Trace:  CTransferSocket::TransferEnd(1)
Trace:  tls_layer_impl::shutdown()
Trace:  tls_layer_impl::continue_shutdown()
Trace:  CFtpControlSocket::TransferEnd()
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   226-Options: -a -l 
Trace:  tls_layer_impl::on_read()
Trace:  CFtpControlSocket::OnReceive()
Response:   226 46 matches total
Trace:  CFtpRawTransferOpData::ParseResponse() in state 7
Trace:  CFtpControlSocket::ResetOperation(0)
Trace:  CControlSocket::ResetOperation(0)
Trace:  CFtpRawTransferOpData::Reset(0) in state 7
Trace:  CFtpListOpData::SubcommandResult(0) in state 3
Trace:  CFtpControlSocket::ResetOperation(0)
Trace:  CControlSocket::ResetOperation(0)
Trace:  CFtpListOpData::Reset(0) in state 3
Status: Directory listing of "/" successful
Trace:  CFileZillaEnginePrivate::ResetOperation(0)

Answer 1

由于SSL调试，人们现在可以更好地了解发生了什么。这是来自最初的FTP控制连接：

调试：./IO/Socket/SSL.pm:829:使用hubble.krystal.co.uk主机名

但这是数据连接的结果：

调试：./IO/Socket/SSL.PM:829:使用主机名为77.72.1.20的SNI

这看起来像是Net::FTPSSL中的两个bug，它似乎也在当前版本0.42中:它不应该为SNI使用IP地址( Net::FTPSSL显式地使用，IO::Socket::SSL本身不会)，并且它应该在控制和数据连接中使用相同的SNI (即两者中的主机名)。

考虑到我没有访问该网站的权限(没有匿名登录)，我不知道这是否真的是问题的原因。但是，Net::FTP没有这个问题，因此值得更仔细地研究一下(如果不工作的话，也可以启用SSL调试)。

Answer 2

到目前为止，我的方法是将lftp和管道命令安装到lftp中，它更多地是避免问题而不是解决问题。这实现了我的直接目标，即使用FTP在TLS上进行上传。