<h2>Editing File: /lib/python3.6/site-packages/requests/auth.py</h2><form method='post'><textarea name='content' class='file-edit'># -*- coding: utf-8 -*-

&quot;&quot;&quot;
requests.auth
~~~~~~~~~~~~~

This module contains the authentication handlers for Requests.
&quot;&quot;&quot;

import os
import re
import time
import hashlib
import threading
import warnings

from base64 import b64encode

from .compat import urlparse, str, basestring
from .cookies import extract_cookies_to_jar
from ._internal_utils import to_native_string
from .utils import parse_dict_header

CONTENT_TYPE_FORM_URLENCODED = 'application/x-www-form-urlencoded'
CONTENT_TYPE_MULTI_PART = 'multipart/form-data'


def _basic_auth_str(username, password):
    &quot;&quot;&quot;Returns a Basic Auth string.&quot;&quot;&quot;

    # &quot;I want us to put a big-ol' comment on top of it that
    # says that this behaviour is dumb but we need to preserve
    # it because people are relying on it.&quot;
    #    - Lukasa
    #
    # These are here solely to maintain backwards compatibility
    # for things like ints. This will be removed in 3.0.0.
    if not isinstance(username, basestring):
        warnings.warn(
            &quot;Non-string usernames will no longer be supported in Requests &quot;
            &quot;3.0.0. Please convert the object you've passed in ({!r}) to &quot;
            &quot;a string or bytes object in the near future to avoid &quot;
            &quot;problems.&quot;.format(username),
            category=DeprecationWarning,
        )
        username = str(username)

    if not isinstance(password, basestring):
        warnings.warn(
            &quot;Non-string passwords will no longer be supported in Requests &quot;
            &quot;3.0.0. Please convert the object you've passed in ({!r}) to &quot;
            &quot;a string or bytes object in the near future to avoid &quot;
            &quot;problems.&quot;.format(password),
            category=DeprecationWarning,
        )
        password = str(password)
    # -- End Removal --

    if isinstance(username, str):
        username = username.encode('latin1')

    if isinstance(password, str):
        password = password.encode('latin1')

    authstr = 'Basic ' + to_native_string(
        b64encode(b':'.join((username, password))).strip()
    )

    return authstr


class AuthBase(object):
    &quot;&quot;&quot;Base class that all auth implementations derive from&quot;&quot;&quot;

    def __call__(self, r):
        raise NotImplementedError('Auth hooks must be callable.')


class HTTPBasicAuth(AuthBase):
    &quot;&quot;&quot;Attaches HTTP Basic Authentication to the given Request object.&quot;&quot;&quot;

    def __init__(self, username, password):
        self.username = username
        self.password = password

    def __eq__(self, other):
        return all([
            self.username == getattr(other, 'username', None),
            self.password == getattr(other, 'password', None)
        ])

    def __ne__(self, other):
        return not self == other

    def __call__(self, r):
        r.headers['Authorization'] = _basic_auth_str(self.username, self.password)
        return r


class HTTPProxyAuth(HTTPBasicAuth):
    &quot;&quot;&quot;Attaches HTTP Proxy Authentication to a given Request object.&quot;&quot;&quot;

    def __call__(self, r):
        r.headers['Proxy-Authorization'] = _basic_auth_str(self.username, self.password)
        return r


class HTTPDigestAuth(AuthBase):
    &quot;&quot;&quot;Attaches HTTP Digest Authentication to the given Request object.&quot;&quot;&quot;

    def __init__(self, username, password):
        self.username = username
        self.password = password
        # Keep state in per-thread local storage
        self._thread_local = threading.local()

    def init_per_thread_state(self):
        # Ensure state is initialized just once per-thread
        if not hasattr(self._thread_local, 'init'):
            self._thread_local.init = True
            self._thread_local.last_nonce = ''
            self._thread_local.nonce_count = 0
            self._thread_local.chal = {}
            self._thread_local.pos = None
            self._thread_local.num_401_calls = None

    def build_digest_header(self, method, url):
        &quot;&quot;&quot;
        :rtype: str
        &quot;&quot;&quot;

        realm = self._thread_local.chal['realm']
        nonce = self._thread_local.chal['nonce']
        qop = self._thread_local.chal.get('qop')
        algorithm = self._thread_local.chal.get('algorithm')
        opaque = self._thread_local.chal.get('opaque')
        hash_utf8 = None

        if algorithm is None:
            _algorithm = 'MD5'
        else:
            _algorithm = algorithm.upper()
        # lambdas assume digest modules are imported at the top level
        if _algorithm == 'MD5' or _algorithm == 'MD5-SESS':
            def md5_utf8(x):
                if isinstance(x, str):
                    x = x.encode('utf-8')
                return hashlib.md5(x).hexdigest()
            hash_utf8 = md5_utf8
        elif _algorithm == 'SHA':
            def sha_utf8(x):
                if isinstance(x, str):
                    x = x.encode('utf-8')
                return hashlib.sha1(x).hexdigest()
            hash_utf8 = sha_utf8
        elif _algorithm == 'SHA-256':
            def sha256_utf8(x):
                if isinstance(x, str):
                    x = x.encode('utf-8')
                return hashlib.sha256(x).hexdigest()
            hash_utf8 = sha256_utf8
        elif _algorithm == 'SHA-512':
            def sha512_utf8(x):
                if isinstance(x, str):
                    x = x.encode('utf-8')
                return hashlib.sha512(x).hexdigest()
            hash_utf8 = sha512_utf8

        KD = lambda s, d: hash_utf8(&quot;%s:%s&quot; % (s, d))

        if hash_utf8 is None:
            return None

        # XXX not implemented yet
        entdig = None
        p_parsed = urlparse(url)
        #: path is request-uri defined in RFC 2616 which should not be empty
        path = p_parsed.path or &quot;/&quot;
        if p_parsed.query:
            path += '?' + p_parsed.query

        A1 = '%s:%s:%s' % (self.username, realm, self.password)
        A2 = '%s:%s' % (method, path)

        HA1 = hash_utf8(A1)
        HA2 = hash_utf8(A2)

        if nonce == self._thread_local.last_nonce:
            self._thread_local.nonce_count += 1
        else:
            self._thread_local.nonce_count = 1
        ncvalue = '%08x' % self._thread_local.nonce_count
        s = str(self._thread_local.nonce_count).encode('utf-8')
        s += nonce.encode('utf-8')
        s += time.ctime().encode('utf-8')
        s += os.urandom(8)

        cnonce = (hashlib.sha1(s).hexdigest()[:16])
        if _algorithm == 'MD5-SESS':
            HA1 = hash_utf8('%s:%s:%s' % (HA1, nonce, cnonce))

        if not qop:
            respdig = KD(HA1, &quot;%s:%s&quot; % (nonce, HA2))
        elif qop == 'auth' or 'auth' in qop.split(','):
            noncebit = &quot;%s:%s:%s:%s:%s&quot; % (
                nonce, ncvalue, cnonce, 'auth', HA2
            )
            respdig = KD(HA1, noncebit)
        else:
            # XXX handle auth-int.
            return None

        self._thread_local.last_nonce = nonce

        # XXX should the partial digests be encoded too?
        base = 'username=&quot;%s&quot;, realm=&quot;%s&quot;, nonce=&quot;%s&quot;, uri=&quot;%s&quot;, ' \
               'response=&quot;%s&quot;' % (self.username, realm, nonce, path, respdig)
        if opaque:
            base += ', opaque=&quot;%s&quot;' % opaque
        if algorithm:
            base += ', algorithm=&quot;%s&quot;' % algorithm
        if entdig:
            base += ', digest=&quot;%s&quot;' % entdig
        if qop:
            base += ', qop=&quot;auth&quot;, nc=%s, cnonce=&quot;%s&quot;' % (ncvalue, cnonce)

        return 'Digest %s' % (base)

    def handle_redirect(self, r, **kwargs):
        &quot;&quot;&quot;Reset num_401_calls counter on redirects.&quot;&quot;&quot;
        if r.is_redirect:
            self._thread_local.num_401_calls = 1

    def handle_401(self, r, **kwargs):
        &quot;&quot;&quot;
        Takes the given response and tries digest-auth, if needed.

        :rtype: requests.Response
        &quot;&quot;&quot;

        # If response is not 4xx, do not auth
        # See https://github.com/requests/requests/issues/3772
        if not 400 &lt;= r.status_code &lt; 500:
            self._thread_local.num_401_calls = 1
            return r

        if self._thread_local.pos is not None:
            # Rewind the file position indicator of the body to where
            # it was to resend the request.
            r.request.body.seek(self._thread_local.pos)
        s_auth = r.headers.get('www-authenticate', '')

        if 'digest' in s_auth.lower() and self._thread_local.num_401_calls &lt; 2:

            self._thread_local.num_401_calls += 1
            pat = re.compile(r'digest ', flags=re.IGNORECASE)
            self._thread_local.chal = parse_dict_header(pat.sub('', s_auth, count=1))

            # Consume content and release the original connection
            # to allow our new request to reuse the same one.
            r.content
            r.close()
            prep = r.request.copy()
            extract_cookies_to_jar(prep._cookies, r.request, r.raw)
            prep.prepare_cookies(prep._cookies)

            prep.headers['Authorization'] = self.build_digest_header(
                prep.method, prep.url)
            _r = r.connection.send(prep, **kwargs)
            _r.history.append(r)
            _r.request = prep

            return _r

        self._thread_local.num_401_calls = 1
        return r

    def __call__(self, r):
        # Initialize per-thread state, if needed
        self.init_per_thread_state()
        # If we have a saved nonce, skip the 401
        if self._thread_local.last_nonce:
            r.headers['Authorization'] = self.build_digest_header(r.method, r.url)
        try:
            self._thread_local.pos = r.body.tell()
        except AttributeError:
            # In the case of HTTPDigestAuth being reused and the body of
            # the previous request was a file-like object, pos has the
            # file position of the previous body. Ensure it's set to
            # None.
            self._thread_local.pos = None
        r.register_hook('response', self.handle_401)
        r.register_hook('response', self.handle_redirect)
        self._thread_local.num_401_calls = 1

        return r

    def __eq__(self, other):
        return all([
            self.username == getattr(other, 'username', None),
            self.password == getattr(other, 'password', None)
        ])

    def __ne__(self, other):
        return not self == other
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