python - 请求(仅)*.google.com 时，SSL3_GET_SERVER_CERTIFICATE 证书验证在 Python 上失败

Question

我遇到了一个非常奇怪的错误，它与 SSL 和 python 到 google.com(或者更一般地说，我认为与具有多个证书链的域)有关。每当我尝试向 https://*.google.com/whatever 发出请求时，都会收到以下错误:

SSLError: ("bad handshake: Error([('SSL routines', 'SSL3_GET_SERVER_CERTIFICATE', 'certificate verify failed')],)",) while doing GET request to URL: https://google.com/

到目前为止我做了什么

我已经经历了很多努力，试图让这个工作正常进行，现在我不知道该怎么做，所以我求助于发布到 Stack Overflow。这是我尝试过的:

1. 注意到 date 返回的日期比实际时间晚 2 分钟(可能使我的证书无效)。我修复了这个假设它会验证证书。这并没有解决问题。

2. 发现 Python 2.7.9 从 Python 3 向后移植了一些 SSL 库。我从 Python 2.7.6 升级到 2.7.9，假设更新(包括此线程中列出的修复:https://serverfault.com/questions/692110/error-with-python2-as-a-https-client-with-an-nginx-server-and-ssl-certificate-ch)会修复它。不走运，同样的错误。

3. 显然设置 verify=False 有效，但我们不愿意在安全性上让步，我们需要让 verify=True 工作。

4. curl https://google.com 也可以按预期工作。这就是我知道它与 Python 的关系。

环境

$ python -V
Python 2.7.9

$ pip list | grep -e requests
requests (2.9.1)

$ uname-a  # ubuntu 14.04
Linux staging.example.com 3.13.0-48-generic #80-Ubuntu SMP Thu Mar 12 11:16:15 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

示例

这仅发生在 https 上的 google 域。这是一个例子:

$ ipython
Python 2.7.9 (default, Jan  6 2016, 21:37:32)
Type "copyright", "credits" or "license" for more information.

IPython 4.0.1 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: import requests

In [2]: requests.get('https://facebook.com', verify=True)
Out[2]: <Response [200]>

In [3]: requests.get('https://stackoverflow.com', verify=True)
Out[3]: <Response [200]>

In [4]: requests.get('https://spotify.com', verify=True)
Out[4]: <Response [200]>

In [5]: requests.get('http://google.com', verify=True) # notice the http
Out[5]: <Response [200]>

In [6]: requests.get('https://google.com', verify=True)
---------------------------------------------------------------------------
SSLError                                  Traceback (most recent call last)
<ipython-input-6-a7fff1831944> in <module>()
----> 1 requests.get('https://google.com', verify=True)

/example/.virtualenv/example/lib/python2.7/site-packages/requests/api.pyc in get(url, params, **kwargs)
     65
     66     kwargs.setdefault('allow_redirects', True)
---> 67     return request('get', url, params=params, **kwargs)
     68
     69

/example/.virtualenv/example/lib/python2.7/site-packages/requests/api.pyc in request(method, url, **kwargs)
     51     # cases, and look like a memory leak in others.
     52     with sessions.Session() as session:
---> 53         return session.request(method=method, url=url, **kwargs)
     54
     55

/example/.virtualenv/example/lib/python2.7/site-packages/requests/sessions.pyc in request(self, method, url, params, data, headers, cookies, files, auth, timeout, allow_redirects, proxies, hooks, stream, verify, cert, json)
    466         }
    467         send_kwargs.update(settings)
--> 468         resp = self.send(prep, **send_kwargs)
    469
    470         return resp

/example/.virtualenv/example/lib/python2.7/site-packages/requests/sessions.pyc in send(self, request, **kwargs)
    574
    575         # Send the request
--> 576         r = adapter.send(request, **kwargs)
    577
    578         # Total elapsed time of the request (approximately)

/example/.virtualenv/example/lib/python2.7/site-packages/requests/adapters.pyc in send(self, request, stream, timeout, verify, cert, proxies)
    445         except (_SSLError, _HTTPError) as e:
    446             if isinstance(e, _SSLError):
--> 447                 raise SSLError(e, request=request)
    448             elif isinstance(e, ReadTimeoutError):
    449                 raise ReadTimeout(e, request=request)

SSLError: ("bad handshake: Error([('SSL routines', 'SSL3_GET_SERVER_CERTIFICATE', 'certificate verify failed')],)",)

Answer 1

我找到了解决方案。正在运行的 certifi 版本似乎存在重大问题。我从这个(很长的)GitHub 问题中发现了这一点:https://github.com/certifi/python-certifi/issues/26

TL;DR

pip uninstall -y certifi && pip install certifi==2015.04.28