Could not connect to Exasol: [SSL: LENGTH_MISMATCH] length mismatch (_ssl.c:1129)

[RomantsovArtur]

Hey, on the latest 0.24.0 version we encounter some strange bug

`

SSLError Traceback (most recent call last)
File /opt/conda/lib/python3.9/site-packages/pyexasol/connection.py:667, in ExaConnection._init_ws(self)
666 try:
--> 667 self._ws = websocket.create_connection(f'{ws_prefix}{ipaddr}:{port}', **ws_options)
668 except Exception as e:

File /opt/conda/lib/python3.9/site-packages/websocket/core.py:606, in create_connection(url, timeout, class, **options)
605 websock.settimeout(timeout if timeout is not None else getdefaulttimeout())
--> 606 websock.connect(url, **options)
607 return websock

File /opt/conda/lib/python3.9/site-packages/websocket/_core.py:249, in WebSocket.connect(self, url, **options)
248 self.sock_opt.timeout = options.get('timeout', self.sock_opt.timeout)
--> 249 self.sock, addrs = connect(url, self.sock_opt, proxy_info(**options),
250 options.pop('socket', None))
252 try:

File /opt/conda/lib/python3.9/site-packages/websocket/_http.py:136, in connect(url, options, proxy, socket)
135 if HAVE_SSL:
--> 136 sock = _ssl_socket(sock, options.sslopt, hostname)
137 else:

File /opt/conda/lib/python3.9/site-packages/websocket/_http.py:274, in _ssl_socket(sock, user_sslopt, hostname)
273 check_hostname = sslopt.get('check_hostname', True)
--> 274 sock = _wrap_sni_socket(sock, sslopt, hostname, check_hostname)
276 return sock

File /opt/conda/lib/python3.9/site-packages/websocket/_http.py:250, in _wrap_sni_socket(sock, sslopt, hostname, check_hostname)
248 context.set_ecdh_curve(sslopt['ecdh_curve'])
--> 250 return context.wrap_socket(
251 sock,
252 do_handshake_on_connect=sslopt.get('do_handshake_on_connect', True),
253 suppress_ragged_eofs=sslopt.get('suppress_ragged_eofs', True),
254 server_hostname=hostname,
255 )

File /opt/conda/lib/python3.9/ssl.py:500, in SSLContext.wrap_socket(self, sock, server_side, do_handshake_on_connect, suppress_ragged_eofs, server_hostname, session)
494 def wrap_socket(self, sock, server_side=False,
495 do_handshake_on_connect=True,
496 suppress_ragged_eofs=True,
497 server_hostname=None, session=None):
498 # SSLSocket class handles server_hostname encoding before it calls
499 # ctx._wrap_socket()
--> 500 return self.sslsocket_class._create(
501 sock=sock,
502 server_side=server_side,
503 do_handshake_on_connect=do_handshake_on_connect,
504 suppress_ragged_eofs=suppress_ragged_eofs,
505 server_hostname=server_hostname,
506 context=self,
507 session=session
508 )

File /opt/conda/lib/python3.9/ssl.py:1040, in SSLSocket._create(cls, sock, server_side, do_handshake_on_connect, suppress_ragged_eofs, server_hostname, context, session)
1039 raise ValueError("do_handshake_on_connect should not be specified for non-blocking sockets")
-> 1040 self.do_handshake()
1041 except (OSError, ValueError):

File /opt/conda/lib/python3.9/ssl.py:1309, in SSLSocket.do_handshake(self, block)
1308 self.settimeout(None)
-> 1309 self._sslobj.do_handshake()
1310 finally:

SSLError: [SSL: LENGTH_MISMATCH] length mismatch (_ssl.c:1129)

During handling of the above exception, another exception occurred:

ExaConnectionFailedError Traceback (most recent call last)
Input In [2], in
----> 1 get_ipython().run_cell_magic('helios_sql', '', '*')

File /opt/conda/lib/python3.9/site-packages/IPython/core/interactiveshell.py:2257, in InteractiveShell.run_cell_magic(self, magic_name, line, cell)
2255 with self.builtin_trap:
2256 args = (magic_arg_s, cell)
-> 2257 result = fn(*args, **kwargs)
2258 return result

File ~/.ipython/profile_default/startup/init.py:107, in SQLMagics.helios_sql(self, _, cell)
105 @cast(Callable, cell_magic)
106 def helios_sql(self, _: str, cell: str) -> pd.DataFrame:
--> 107 with get_exasol_connection() as con, con.execute(cell) as st:
108 return pd.DataFrame(st.fetchmany(1000))

File ~/.ipython/profile_default/startup/init.py:27, in get_exasol_connection()
25 if not Path(config_path).exists():
26 raise FileNotFoundError("Sorry, your Helios connection has not yet been configured")
---> 27 return pyexasol.connect_local_config("helios", config_path)

File /opt/conda/lib/python3.9/site-packages/pyexasol/init.py:86, in connect_local_config(config_section, config_path, kwargs)
83 conf = ExaLocalConfig(config_path)
84 conf_args = conf.get_args(config_section)
---> 86 return connect({**conf_args, **kwargs})

File /opt/conda/lib/python3.9/site-packages/pyexasol/init.py:68, in connect(**kwargs)
63 def connect(**kwargs) -> ExaConnection:
64 """
65 Constructor of connection objects
66 Please check ExaConnection object for list of arguments
67 """
---> 68 return ExaConnection(**kwargs)

File /opt/conda/lib/python3.9/site-packages/pyexasol/connection.py:184, in ExaConnection.init(self, dsn, user, password, schema, autocommit, snapshot_transactions, connection_timeout, socket_timeout, query_timeout, compression, encryption, fetch_dict, fetch_mapper, fetch_size_bytes, lower_ident, quote_ident, json_lib, verbose_error, debug, debug_logdir, udf_output_bind_address, udf_output_connect_address, udf_output_dir, http_proxy, client_name, client_version, client_os_username, protocol_version, websocket_sslopt, access_token, refresh_token)
181 self._init_meta()
183 self._init_logger()
--> 184 self._init_ws()
186 self._login()
187 self.get_attr()

File /opt/conda/lib/python3.9/site-packages/pyexasol/connection.py:674, in ExaConnection._init_ws(self)
671 failed_attempts += 1
673 if failed_attempts == len(dsn_items):
--> 674 raise ExaConnectionFailedError(self, 'Could not connect to Exasol: ' + str(e))
675 else:
676 self._ws.settimeout(self.options['socket_timeout'])

ExaConnectionFailedError:
(
message => Could not connect to Exasol: [SSL: LENGTH_MISMATCH] length mismatch (_ssl.c:1129)
dsn => *:8888
user => *
schema =>
session_id =>
)
`

[RomantsovArtur]

If we downgrade to the 0.23.3 it works perfectly fine. We have no other changes than except upgrade to 0.24.0 and can reproduce the issue

[RomantsovArtur]

Could you please take a look?

[littleK0i]

It happens because of: #84

Now encryption is enabled by default.

How it can be fixed:

• Update OpenSSL. You probably have a very old OpenSSL version which is no longer "safe" to use.
• Set encryption=False in connection options explicitly.
• You can rollback to 0.23.3 and pin this version in dependencies until you can fix the environment.

I'll pin this issue. I expect a lot of customers to encounter it.

[RomantsovArtur]

Thank you for the info! 🎉

I'm closing this issue.