问题描述

所以，我正在尝试连接到 FTP 服务器以获取目录列表并下载文件.但是 prot_p() 函数之后的第一个命令引发了异常 - 从日志中产生这些错误:

So, I am trying to connect to an FTP server to get directory listings and download files. But the first command after the prot_p() function is raising an exception - Producing these errors from the log:

*get* '150 Here comes the directory listing.
'
*resp* '150 Here comes the directory listing.'
*get* '522 SSL connection failed; session reuse required: see require_ssl_reuse
option in vsftpd.conf man page
'
*resp* '522 SSL connection failed; session reuse required: see require_ssl_reuse
 option in vsftpd.conf man page'
Traceback (most recent call last):
  File "C:	empdownload.py", line 29, in <module>
    files = ftps.dir()
  File "C:Python27libftplib.py", line 522, in dir
    self.retrlines(cmd, func)
  File "C:Python27libftplib.py", line 725, in retrlines
    return self.voidresp()
  File "C:Python27libftplib.py", line 224, in voidresp
    resp = self.getresp()
  File "C:Python27libftplib.py", line 219, in getresp
    raise error_perm, resp
ftplib.error_perm: 522 SSL connection failed; session reuse required: see requir
e_ssl_reuse option in vsftpd.conf man page

代码如下:

from ftplib import FTP_TLS
import os
import socket

host = 'example.com'
port = 34567
user = 'user1'
passwd = 'pass123'
acct = 'Normal'

ftps = FTP_TLS()

ftps.set_debuglevel(2)

ftps.connect(host, port)

print(ftps.getwelcome())
print(ftps.sock)

ftps.auth()

ftps.login(user, passwd, acct)

ftps.set_pasv(True)
ftps.prot_p()

print('Current directory:')
print(ftps.pwd())
files = ftps.dir()

ftps.quit()

我想安全地执行此操作，因此使用 FTP over TLS Explicit.我的想法是我可能需要操作 ftplib 引用的 Socket 类中的一些设置.更改服务器上的设置是不可能的.我已经使用 FileZilla 客户端成功测试了服务器，但旧版本的 WinSCP 引发了同样的错误 - 尽管升级到最新版本修复了它.

I want to do this securely, hence using FTP over TLS Explicit. I have the idea that I may need to manipulate some settings in the Socket class referenced by ftplib. Changing the settings on the server is not a possibility. I have tested the server successfully with FileZilla client, an older version of WinSCP was raising the same error - although an upgrade to the newest version fixed it.

有什么想法吗?

推荐答案

现在可以通过这个类(FTP_TLS的后代)轻松修复Python 3.6+:

It can be now easily fixed for Python 3.6+ by this class (descendant of FTP_TLS):

class MyFTP_TLS(ftplib.FTP_TLS):
    """Explicit FTPS, with shared TLS session"""
    def ntransfercmd(self, cmd, rest=None):
        conn, size = ftplib.FTP.ntransfercmd(self, cmd, rest)
        if self._prot_p:
            conn = self.context.wrap_socket(conn,
                                            server_hostname=self.host,
                                            session=self.sock.session)  # this is the fix
        return conn, size