[New-bugs-announce] [issue17518] urllib2 cannnot handle https and BasicAuth via Proxy.

[masato]

New submission from masato:

When urllib2 module is used, https connections to servers that BasicAuth is required, via proxies, can not be established properly.

Sample code:
import urllib2

def main():
    url = "https://example.com/aplication/rpc"
    
    proxy_support = urllib2.ProxyHandler({'http': 'http://proxy.server.com:8080/','https': 'http://proxy.server.com:8080/'})

    pass_mngr = urllib2.HTTPPasswordMgrWithDefaultRealm()
    pass_mngr.add_password(None, url, 'user', 'password')
    auth_handler = urllib2.HTTPBasicAuthHandler(pass_mngr)
    
    opener = urllib2.build_opener(proxy_support,auth_handler)
    req = urllib2.Request(url)
    f = opener.open(req)
    print f.read()


"opener.open" method throws an exception.

I found a similar case at http://bugs.python.org/issue7291. However, this issue indicates a case of authentication at a proxy server. In my case, the origin server uses basic authentication.

The origin server address is not set in Request URI in the https request in case of using proxy servers, because https request gets encripted with SSL when it passes through proxies.

urllib2 works well for the first on-going request and in-comming return. However, after the first in-comming return (401 code), urllib2 module sends a worng request that includes the origin server URL.

I suggest modification for set_proxy method in Request class.

Original code:
def set_proxy(self, host, type):
        if self.type == 'https' and not self._tunnel_host:
            self._tunnel_host = self.host
        else:
            self.type = type
            self.__r_host = self.__original

        self.host = host

As a value is already set to tunnel_host when the second out-going request is sent, "self.type == 'https' and not self._tunnel_host" is false.

Code suggested:
def set_proxy(self, host, type):
        if self.type == 'https' and not self._tunnel_host:
            self._tunnel_host = self.host
        else:
            self.type = type
            if self.type != 'https':
                self.__r_host = self.__original

        self.host = host


regards.

----------
components: Library (Lib)
messages: 184958
nosy: masato kawamura
priority: normal
severity: normal
status: open
title: urllib2 cannnot handle https and BasicAuth via Proxy.
type: crash
versions: Python 2.7

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue17518>
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