Question

我使用python3和imaplib连接到Exchange服务器。 Exchange服务器使用为主机名＆＃39; my.server.fqdn＆＃39;创建的自签名证书。在我的工作站上最近的操作系统升级（Ubuntu 14.04）后，我的python脚本不再有效。

我使用的基本代码片段在这里：

#!/usr/bin/python3

import imaplib
import socket
import ssl
import getpass

passwd = getpass.getpass()
mail =  imaplib.IMAP4_SSL('my.server.fqdn', 1143)  
mail.login('mike', passwd)
mail.list()
mail.select("INBOX")

在升级之前，代码运行正常。现在这段代码产生了这个错误：

Traceback (most recent call last):
  File "./example.py", line 9, in <module>
    mail =  imaplib.IMAP4_SSL('my.server.fqdn', 1143)  
  File "/usr/lib/python3.4/imaplib.py", line 1222, in __init__
    IMAP4.__init__(self, host, port)
  File "/usr/lib/python3.4/imaplib.py", line 181, in __init__
    self.open(host, port)
  File "/usr/lib/python3.4/imaplib.py", line 1236, in open
    IMAP4.open(self, host, port)
  File "/usr/lib/python3.4/imaplib.py", line 257, in open
    self.sock = self._create_socket()
  File "/usr/lib/python3.4/imaplib.py", line 1228, in _create_socket
    server_hostname=server_hostname)
  File "/usr/lib/python3.4/ssl.py", line 364, in wrap_socket
    _context=self)
  File "/usr/lib/python3.4/ssl.py", line 578, in __init__
    self.do_handshake()
  File "/usr/lib/python3.4/ssl.py", line 805, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLError: [SSL: TLSV1_ALERT_INTERNAL_ERROR] tlsv1 alert internal error (_ssl.c:598)

如果python遇到自签名证书，SSL版本的问题，或者如果python 3中有新内容不能使用我的旧代码，那么这对我来说并不明显。

我有一个来自Exchange服务器的PEM文件，它允许我使用curl连接到服务器。身份验证失败，但在SSL握手期间检查curl似乎正常工作。我必须提供curl --sslv3选项以及PEM文件的路径以使其正常工作。如果这就是我需要用python来重新开始工作，我该如何为python提供相同的信息呢？

curl session在这里：

$ curl -vvv --sslv3 https://my.server.fqdn:1143 --cacert ~/my_server_fqdn.pem 
    * Rebuilt URL to: https://my.server.fqdn:1143/
    * Hostname was NOT found in DNS cache
    *   Trying 10.10.10.10...
    * Connected to my.server.fqdn (10.10.10.10) port 1143 (#0)
    * successfully set certificate verify locations:
    *   CAfile: /home/username/my_server_fqdn.pem
      CApath: /etc/ssl/certs
    * SSLv3, TLS handshake, Client hello (1):
    * SSLv3, TLS handshake, Server hello (2):
    * SSLv3, TLS handshake, CERT (11):
    * SSLv3, TLS handshake, Server key exchange (12):
    * SSLv3, TLS handshake, Server finished (14):
    * SSLv3, TLS handshake, Client key exchange (16):
    * SSLv3, TLS change cipher, Client hello (1):
    * SSLv3, TLS handshake, Finished (20):
    * SSLv3, TLS change cipher, Client hello (1):
    * SSLv3, TLS handshake, Finished (20):
    * SSL connection using ECDHE-RSA-AES256-SHA
    * Server certificate:
    *        subject: O=fqdn; O=SERVER; OU=M; CN=my.server.fqdn
    *        start date: 2013-07-29 20:59:04 GMT
    *        expire date: 2023-07-27 20:59:04 GMT
    *        common name: my.server.fqdn (matched)
    *        issuer: O=fqdn; O=SERVER; OU=M; CN=my.server.fqdn
    *        SSL certificate verify ok.
    > GET / HTTP/1.1
    > User-Agent: curl/7.35.0
    > Host: my.server.fqdn:1143
    > Accept: */*
    > 
    * OK [CAPABILITY IMAP4REV1 AUTH=LOGIN MOVE] IMAP4rev1 server ready
    GET BAD command authentication required
    User-Agent: BAD command authentication required
    Host: BAD command authentication required
    Accept: BAD command authentication required
    * SSLv3, TLS alert, Client hello (1):
    * Connection #0 to host my.server.fqdn left intact

Answer 1

显然这个问题是由Ubuntu 12.04和14.04上的openssl包中的一个或多个versions of TLS protocol being disabled引起的。我最终在python3中使用ssl上下文并强制连接SSL版本3。这似乎现在有效。真的希望这可以帮助任何人解决同样的问题。

#!/usr/bin/python3

import imaplib
import socket
import ssl
import getpass

ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv3)  
passwd = getpass.getpass()
mail =  imaplib.IMAP4_SSL('my.server.fqdn', 1143, ssl_context=ctx)
mail.login('mike', passwd)
mail.select('INBOX', 1)
typ, uids = mail.uid("SEARCH", None, "ALL")

uids = uids[0].split()
for u in uids:
   print ("found uid " , u)

mail.close()
mail.logout()
del mail

如何连接Python IMAP4_SSL和自签名服务器SSL证书？

1 个答案: