I want to connect to an FTPS server containing some not trusted certificate. When I use simple:
lftp -u user hostname
then after dir command there's an error:
ls: Fatal error: Certificate verification: Not trusted
The problem can be solved in lftp by executing the following command:
lftp -e "set ssl:verify-certificate false" -u user hostname
I'm trying to make the same connection in Python, using for example ftplib module:
import ftplib
ftp = ftplib.FTP_TLS()
ftp.connect(hostname, port)
ftp.login(username, password)
ftp.prot_p()
ftp.dir()
But it raises OSError exception:
Traceback (most recent call last):
File "/usr/lib/python3.8/code.py", line 90, in runcode
exec(code, self.locals)
File "<console>", line 1, in <module>
File "/usr/lib/python3.8/ftplib.py", line 558, in dir
self.retrlines(cmd, func)
File "/usr/lib/python3.8/ftplib.py", line 451, in retrlines
with self.transfercmd(cmd) as conn, \
File "/usr/lib/python3.8/ftplib.py", line 382, in transfercmd
return self.ntransfercmd(cmd, rest)[0]
File "/usr/lib/python3.8/ftplib.py", line 783, in ntransfercmd
conn = self.context.wrap_socket(conn,
File "/usr/lib/python3.8/ssl.py", line 500, in wrap_socket
return self.sslsocket_class._create(
File "/usr/lib/python3.8/ssl.py", line 1040, in _create
self.do_handshake()
File "/usr/lib/python3.8/ssl.py", line 1309, in do_handshake
self._sslobj.do_handshake()
OSError: [Errno 0] Error
The problem seems to be similar to te OSError during authenticating to an ftps server with ftplib.FTP_TLS so I also tried to use some other context, like:
import ssl
ctx = ssl._create_stdlib_context(ssl.PROTOCOL_TLSv1_2)
ftp = FTP_TLS(context=ctx)
or
ctx = ssl.ssl._create_unverified_context(ssl.PROTOCOL_TLSv1_2)
ftp = FTP_TLS(context=ctx)
But the error is still the same. Any ideas how to disable certificate verification?
It cannot be a certificate problem, as you are getting error only at dir. The connect succeeds.
You get a TLS error when opening FTP data connection. It quite possible that the root cause is that the server require TLS session resumption.