title: pip SSL Certificate error even with trusted source
body: <p>I am trying to install the package requests_ntlm.
  If I try to use the following command, I still receive an SSL Error:</p>
  
  <pre><code> pip install --trusted-host pypi.python.org --proxy http://username:password@site.address:port requests_ntlm
  </code></pre>
  
  <p>I have tried adding <code>--index-url=http://pypi.python.org/simple/</code>, changing the trusted and index URL to http:/pypi.python.org, https:pypi.org, <a href="http://pypi.python.org/" rel="nofollow noreferrer">http://pypi.python.org/</a>, <a href="http://pypi.python.org/pypi/" rel="nofollow noreferrer">http://pypi.python.org/pypi/</a> but I end up with the same result.</p>
  
  <p>including <code>-v</code> returns the following:</p>
  
  <pre><code>pip install --trusted-host pypi.python.org --proxy http://username@password@site.address:port -v requests_ntlm
  Config variable 'Py_DEBUG' is unset, Python ABI tag may be incorrect
  Config variable 'WITH_PYMALLOC' is unset, Python ABI tag may be incorrect
  Collecting requests_ntlm
  1 location(s) to search for versions of requests-ntlm:
  * https://pypi.python.org/simple/requests-ntlm/
  Getting page https://pypi.python.org/simple/requests-ntlm/
  Starting new HTTPS connection (1): pypi.python.org
  https://pypi.python.org:443 "GET /simple/requests-ntlm/ HTTP/1.1" 301 122
  Looking up "https://pypi.org/simple/requests-ntlm/" in the cache
  No cache entry available
  Starting new HTTPS connection (1): pypi.org
  Incremented Retry for (url='/simple/requests-ntlm/'): Retry(total=4, connect=None, read=None, redirect=None, status=None)
  Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),)': /simple/requests-ntlm/
  Starting new HTTPS connection (2): pypi.org
  Incremented Retry for (url='/simple/requests-ntlm/'): Retry(total=3, connect=None, read=None, redirect=None, status=None)
  Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),)': /simple/requests-ntlm/
  Starting new HTTPS connection (3): pypi.org
  Incremented Retry for (url='/simple/requests-ntlm/'): Retry(total=2, connect=None, read=None, redirect=None, status=None)
  Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),)': /simple/requests-ntlm/
  Starting new HTTPS connection (4): pypi.org
  Incremented Retry for (url='/simple/requests-ntlm/'): Retry(total=1, connect=None, read=None, redirect=None, status=None)
  Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),)': /simple/requests-ntlm/
  Starting new HTTPS connection (5): pypi.org
  Incremented Retry for (url='/simple/requests-ntlm/'): Retry(total=0, connect=None, read=None, redirect=None, status=None)
  Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),)': /simple/requests-ntlm/
  Starting new HTTPS connection (6): pypi.org
  Could not fetch URL https://pypi.python.org/simple/requests-ntlm/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/requests-ntlm/ (Caused by SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),)) - skipping
  Could not find a version that satisfies the requirement requests_ntlm (from versions: )
  Cleaning up...
  No matching distribution found for requests_ntlm
  </code></pre>
  
  <p>This question is similar to <a href="https://stackoverflow.com/questions/25981703/pip-install-fails-with-connection-error-ssl-certificate-verify-failed-certi?utm_medium=organic&amp;utm_source=google_rich_qa&amp;utm_campaign=google_rich_qa">this question</a> but with the difference in that I have tried the popular answer of appending <code>--trusted-host</code></p>
  
  <p>Anyone have any ideas why?</p>