python - 在 Android 上执行 Python 脚本时出现 "SSLError: [SSL: BAD_SIGNATURE] bad signature (_ssl.c:726)"异常

Question

我有一个简单的 Python 脚本，它在 Windows 10 上的 Python 2.7 上运行得很好。

however it gives me

"SSLError: [SSL: BAD_SIGNATURE] bad signature (_ssl.c:726)" 

error when I run it from Android.

代码很简单，如下:

import urllib
import urllib2
import ssl
import traceback

#ssl._https_verify_certificates(False)
#ssl._create_default_https_context = ssl._create_unverified_context

try:

    url="https://stackoverflow.com/"
    https_context = ssl._create_unverified_context(cert_reqs=ssl.CERT_NONE,check_hostname=False)
    https_handler = urllib2.HTTPSHandler(context=https_context)
    opener = urllib2.build_opener(https_handler)
    rep=opener.open(url)
    print(rep.read())
except Exception, e:
    urllib.urlopen("http://c.seechentech.com/exception?code=484&error=%s&u=%s" % (traceback.format_exc(), url))

经过一番调查，我发现这个异常是在套接字握手期间引发的，但我已经将证书验证设置为False(不需要为我验证证书)，为什么它会检查签名？如何解决这个问题？

Answer 1

这个问题已经解决，我想分享我的发现。

发现 1:无论是否设置为验证证书，由 Python Socket 调用的 OpenSSL 套接字将始终在需要 PEM 证书的地方进行 SSL 握手。这一发现回答了为什么我的代码在套接字握手期间失败。

发现 2:Python 能够从 Windows 10 默认位置加载系统受信任的 CA，但是，它在 Android 上失败。这可能是由两个潜在原因引起的:

1) Python 在 Andorid 上找不到默认的 CA 位置/system/etc/security/cacerts/

2) Python 期望 CA 为 PEM 格式，但 Android 信任的 CA 在 ---END CERTIFICAT--- 之后有额外的行，这是 CA 内容结束的标志。

具体是什么原因导致CA证书加载失败我没有验证。我为 Python 提供正确的 CA 数据所做的工作是将从一台 Android 设备提取的所有 CA 文件合并到一个文件中，并使用 load_verify_locations 方法设置为 ssl.SSLContext。

发现 3:与 Windows 上的受信任 CA 相比，Android 上缺少一些受信任的 CA，因此我必须手动将它们添加到我的组合 CA 文件中。

发现 4:Python 文档说“如果你想要客户端和服务器之间的最大兼容性，建议使用 PROTOCOL_SSLv23 作为协议(protocol)版本”，这是不正确的。当我使用这个协议(protocol)版本时，它会导致无效的认证错误。 ssl.PROTOCOL_TLSv1 协议(protocol)版本适用于我的情况。

发现 5:Python 文档说将证书作为“ASCII PEM 字符串”提供，这是不正确的。我们必须提供一个 unicode 字符串。

引用代码如下:

#!/usr/bin/python
# -*- coding: UTF-8 -*-
import sys
reload(sys) 
sys.setdefaultencoding("utf-8")
import os
from os import path
import urllib
import urllib2
import ssl

import traceback
import shutil


def loadCA():

    concatedCA = u'''
-----BEGIN CERTIFICATE-----
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
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
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
-----END CERTIFICATE-----
'''

    return  concatedCA


cadata = loadCA()

try:

    url="https://stackoverflow.com/"


    https_context = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
    https_context.verify_mode = ssl.CERT_NONE
    https_context.check_hostname = False
    https_context.load_verify_locations(cadata=cadata)

    https_handler = urllib2.HTTPSHandler(debuglevel=1,context=https_context)

    redirect_handler = SmartRedirectHandler()

    opener = urllib2.build_opener(https_handler,redirect_handler)
    rep=opener.open(url)

except Exception, e:
    traceback.print_exc()