# Source code for mechanize._urllib2_fork

    """Fork of urllib2.

    When reading this, don't assume that all code in here is reachable.  Code in
    the rest of mechanize may be used instead.

    Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Python
    Software Foundation; All Rights Reserved

    Copyright 2002-2009 John J Lee <jjl@pobox.com>

    This code is free software; you can redistribute it and/or modify it
    under the terms of the BSD or ZPL 2.1 licenses (see the file
    LICENSE included with the distribution).

    """

    # XXX issues:
    # If an authentication error handler that tries to perform
    # authentication for some reason but fails, how should the error be
    # signalled?  The client needs to know the HTTP error code.  But if
    # the handler knows that the problem was, e.g., that it didn't know
    # that hash algo that requested in the challenge, it would be good to
    # pass that information along to the client, too.
    # ftp errors aren't handled cleanly
    # check digest against correct (i.e. non-apache) implementation

    # Possible extensions:
    # complex proxies  XXX not sure what exactly was meant by this
    # abstract factory for opener

    from __future__ import absolute_import

    import base64
    import bisect
    import copy
    import hashlib
    import logging
    import os
    import platform
    import posixpath
    import re
    import socket
    import sys
    import time
    from collections import OrderedDict
    from functools import partial
    from io import BufferedReader, BytesIO

    from . import _rfc3986
    from ._clientcookie import CookieJar
    from ._headersutil import normalize_header_name
    from ._response import closeable_response
    from .polyglot import (HTTPConnection, HTTPError, HTTPSConnection, URLError,
                           as_unicode, create_response_info, ftpwrapper,
                           getproxies, is_class, is_mapping, is_py2, is_string,
                           iteritems, map, raise_with_traceback, splitattr,
                           splitpasswd, splitport, splittype, splituser,
                           splitvalue, unquote, unwrap, url2pathname,
                           urllib_proxy_bypass, urllib_splithost, urlparse,
                           urlsplit, urlunparse)

    def sha1_digest(data):
        if not isinstance(data, bytes):
            data = data.encode('utf-8')
        return hashlib.sha1(data).hexdigest()

    def md5_digest(data):
        if not isinstance(data, bytes):
            data = data.encode('utf-8')
        return hashlib.md5(data).hexdigest()

    if platform.python_implementation() == 'PyPy':
        def create_readline_wrapper(fh):
            fh.recv = fh.read
            if not hasattr(fh, '_drop'):
                fh._drop = lambda: None
                fh._reuse = lambda: None
            return socket._fileobject(fh, close=True)
    else:
        def create_readline_wrapper(fh):
            fh.recv = fh.read
            if is_py2:
                ans = socket._fileobject(fh, close=True)
            else:
                fh.recv_into = fh.readinto
                fh._decref_socketios = lambda: None
                ans = BufferedReader(socket.SocketIO(fh, 'r'))
            return ans

    splithost = urllib_splithost

    # used in User-Agent header sent
    __version__ = sys.version[:3]

    _opener = None

    def urlopen(url, data=None):
        global _opener
        if _opener is None:
            _opener = build_opener()
        return _opener._open(url, data)

    def install_opener(opener):
        global _opener
        _opener = opener

    # copied from cookielib.py
    _cut_port_re = re.compile(r":\d+$")

    def request_host(request):
        """Return request-host, as defined by RFC 2965.

        Variation from RFC: returned value is lowercased, for convenient
        comparison.

        """
        url = request.get_full_url()
        host = urlparse(url)[1]
        if host == "":
            host = request.get_header("Host", "")

        # remove port, if present
        host = _cut_port_re.sub("", host, 1)
        return host.lower()

    PERCENT_RE = re.compile(b"%[a-fA-F0-9]{2}")
    ZONE_ID_CHARS = set(bytearray(
        b"ABCDEFGHIJKLMNOPQRSTUVWXYZ" b"abcdefghijklmnopqrstuvwxyz" b"0123456789._!-"
    ))
    USERINFO_CHARS = ZONE_ID_CHARS | set(bytearray(b"$&'()*+,;=:"))
    PATH_CHARS = USERINFO_CHARS | set(bytearray(b'@/'))
    QUERY_CHARS = FRAGMENT_CHARS = PATH_CHARS | {ord(b"?")}

    def fix_invalid_bytes_in_url_component(component, allowed_chars=PATH_CHARS):
        if not component:
            return component
        is_bytes = isinstance(component, bytes)
        if not is_bytes:
            component = component.encode('utf-8', 'surrogatepass')
        percent_encodings = PERCENT_RE.findall(component)
        for enc in percent_encodings:
            if not enc.isupper():
                component = component.replace(enc, enc.upper())
        is_percent_encoded = len(percent_encodings) == component.count(b"%")
        encoded_component = bytearray()
        percent = ord('%')
        for byte_ord in bytearray(component):
            if (is_percent_encoded and byte_ord == percent) or (byte_ord < 128 and byte_ord in allowed_chars):
                encoded_component.append(byte_ord)
                continue
            encoded_component.extend(b"%" + (hex(byte_ord)[2:].encode().zfill(2).upper()))
        encoded_component = bytes(encoded_component)
        if not is_bytes:
            encoded_component = encoded_component.decode('utf-8')
        return encoded_component

    def normalize_url(url):
        parsed = urlparse(url)
        netloc = parsed.netloc
        if not isinstance(netloc, bytes) and netloc:
            def safe_encode(label):
                try:
                    return label.encode('idna').decode('ascii')
                except ValueError:
                    return label.encode('ascii', 'replace').decode('ascii')
            netloc = u'.'.join(map(safe_encode, netloc.split(u'.')))

        return urlunparse(parsed._replace(
            path=fix_invalid_bytes_in_url_component(parsed.path), netloc=netloc,
            query=fix_invalid_bytes_in_url_component(parsed.query, QUERY_CHARS),
            fragment=fix_invalid_bytes_in_url_component(parsed.fragment, FRAGMENT_CHARS),
        ))

    class Request:

        def __init__(self, url, data=None, headers={},
                     origin_req_host=None, unverifiable=False, method=None):
            # unwrap('<URL:type://host/path>') --> 'type://host/path'
            self.__original = normalize_url(unwrap(url))
            self.type = None
            self._method = method and str(method)
            # self.__r_type is what's left after doing the splittype
            self.host = None
            self.port = None
            self._tunnel_host = None
            self.data = data
            self.headers = OrderedDict()
            for key, value in iteritems(headers):
                self.add_header(key, value)
            self.unredirected_hdrs = OrderedDict()
            if origin_req_host is None:
                origin_req_host = request_host(self)
            self.origin_req_host = origin_req_host
            self.unverifiable = unverifiable
            try:
                self.get_host()  # in py3 cookiejar expect self.host to be not None
            except Exception:
                self.host = None

        def __getattr__(self, attr):
            # XXX this is a fallback mechanism to guard against these
            # methods getting called in a non-standard order.  this may be
            # too complicated and/or unnecessary.
            # XXX should the __r_XXX attributes be public?
            if attr[:12] == '_Request__r_':
                name = attr[12:]
                if hasattr(Request, 'get_' + name):
                    getattr(self, 'get_' + name)()
                    return getattr(self, attr)
            raise AttributeError(attr)

        def get_method(self):
            ' The method used for HTTP requests '
            if self._method is None:
                return "POST" if self.has_data() else 'GET'
            return self._method

        # XXX these helper methods are lame

        def set_data(self, data):
            ' Set the data (a bytestring) to be sent with this request '
            self.data = data
        add_data = set_data

        def has_data(self):
            ' True iff there is some data to be sent with this request '
            return self.data is not None

        def get_data(self):
            ' The data to be sent with this request '
            return self.data

        def get_full_url(self):
            return self.__original

        @property
        def full_url(self):
            # In python 3 this is a deleteable and settable property, which when
            # deleted gets set to None. But this interface does not seem to be used
            # by any stdlib code, so this should be sufficient.
            return self.__original

        def get_type(self):
            if self.type is None:
                self.type, self.__r_type = splittype(self.__original)
                if self.type is None:
                    raise ValueError("unknown url type: %s" % self.__original)
            return self.type

        def get_host(self):
            if self.host is None:
                self.host, self.__r_host = splithost(self.__r_type)
                if self.host:
                    self.host = unquote(self.host)
            return self.host

        def get_selector(self):
            scheme, authority, path, query, fragment = _rfc3986.urlsplit(
                self.__r_host)
            if path == "":
                path = "/"  # RFC 2616, section 3.2.2
            fragment = None  # RFC 3986, section 3.5
            return _rfc3986.urlunsplit([scheme, authority, path, query, fragment])

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

            self.host = host

        def has_proxy(self):
            """Private method."""
            # has non-HTTPS proxy
            return self.__r_host == self.__original

        def get_origin_req_host(self):
            return self.origin_req_host

        def is_unverifiable(self):
            return self.unverifiable

        def add_header(self, key, val=None):
            ''' Add the specified header, replacing existing one, if needed. If val
            is None, remove the header. '''
            # useful for something like authentication
            key = normalize_header_name(key)
            if val is None:
                self.headers.pop(key, None)
            else:
                self.headers[key] = val

        def add_unredirected_header(self, key, val):
            ''' Same as :meth:`add_header()` except that this header will not
            be sent for redirected requests. '''
            key = normalize_header_name(key)
            if val is None:
                self.unredirected_hdrs.pop(key, None)
            else:
                self.unredirected_hdrs[key] = val

        def has_header(self, header_name):
            ''' Check if the specified header is present '''
            header_name = normalize_header_name(header_name)
            return (header_name in self.headers or
                    header_name in self.unredirected_hdrs)

        def get_header(self, header_name, default=None):
            ''' Get the value of the specified header. If absent, return `default`
            '''
            header_name = normalize_header_name(header_name)
            return self.headers.get(
                header_name,
                self.unredirected_hdrs.get(header_name, default))

        def header_items(self):
            ''' Get a copy of all headers for this request as a list of 2-tuples
            '''
            hdrs = self.unredirected_hdrs.copy()
            hdrs.update(self.headers)
            return list(iteritems(hdrs))

    class OpenerDirector(object):

        def __init__(self):
            client_version = "Python-urllib/%s" % __version__
            self.addheaders = [('User-agent', client_version)]
            self.finalize_request_headers = None
            # manage the individual handlers
            self.handlers = []
            self.handle_open = {}
            self.handle_error = {}
            self.process_response = {}
            self.process_request = {}

        def add_handler(self, handler):
            if not hasattr(handler, "add_parent"):
                raise TypeError("expected BaseHandler instance, got %r" %
                                type(handler))

            added = False
            for meth in dir(handler):
                if meth in ["redirect_request", "do_open", "proxy_open"]:
                    # oops, coincidental match
                    continue

                i = meth.find("_")
                protocol = meth[:i]
                condition = meth[i + 1:]

                if condition.startswith("error"):
                    j = condition.find("_") + i + 1
                    kind = meth[j + 1:]
                    try:
                        kind = int(kind)
                    except ValueError:
                        pass
                    lookup = self.handle_error.get(protocol, {})
                    self.handle_error[protocol] = lookup
                elif condition == "open":
                    kind = protocol
                    lookup = self.handle_open
                elif condition == "response":
                    kind = protocol
                    lookup = self.process_response
                elif condition == "request":
                    kind = protocol
                    lookup = self.process_request
                else:
                    continue

                handlers = lookup.setdefault(kind, [])
                if handlers:
                    bisect.insort(handlers, handler)
                else:
                    handlers.append(handler)
                added = True

            if added:
                # the handlers must work in an specific order, the order
                # is specified in a Handler attribute
                bisect.insort(self.handlers, handler)
                handler.add_parent(self)

        def close(self):
            # Only exists for backwards compatibility.
            pass

        def _call_chain(self, chain, kind, meth_name, *args):
            # Handlers raise an exception if no one else should try to handle
            # the request, or return None if they can't but another handler
            # could.  Otherwise, they return the response.
            handlers = chain.get(kind, ())
            for handler in handlers:
                func = getattr(handler, meth_name)

                result = func(*args)
                if result is not None:
                    return result

        def _open(self, req, data=None):
            result = self._call_chain(self.handle_open, 'default',
                                      'default_open', req)
            if result:
                return result

            protocol = req.get_type()
            result = self._call_chain(self.handle_open, protocol, protocol +
                                      '_open', req)
            if result:
                return result

            return self._call_chain(self.handle_open, 'unknown',
                                    'unknown_open', req)

        def error(self, proto, *args):
            if proto in ('http', 'https'):
                # XXX http[s] protocols are special-cased
                # https is not different than http
                dict = self.handle_error['http']
                proto = args[2]  # YUCK!
                meth_name = 'http_error_%s' % proto
                http_err = 1
                orig_args = args
            else:
                dict = self.handle_error
                meth_name = proto + '_error'
                http_err = 0
            args = (dict, proto, meth_name) + args
            result = self._call_chain(*args)
            if result:
                return result

            if http_err:
                args = (dict, 'default', 'http_error_default') + orig_args
                return self._call_chain(*args)

    # XXX probably also want an abstract factory that knows when it makes
    # sense to skip a superclass in favor of a subclass and when it might
    # make sense to include both

    def build_opener(*handlers):
        """Create an opener object from a list of handlers.

        The opener will use several default handlers, including support
        for HTTP, FTP and when applicable, HTTPS.

        If any of the handlers passed as arguments are subclasses of the
        default handlers, the default handlers will not be used.
        """
        opener = OpenerDirector()
        default_classes = [ProxyHandler, UnknownHandler, HTTPHandler,
                           HTTPDefaultErrorHandler, HTTPRedirectHandler,
                           FTPHandler, FileHandler, HTTPErrorProcessor]
        default_classes.append(HTTPSHandler)
        skip = set()
        for klass in default_classes:
            for check in handlers:
                if is_class(check):
                    if issubclass(check, klass):
                        skip.add(klass)
                elif isinstance(check, klass):
                    skip.add(klass)
        for klass in skip:
            default_classes.remove(klass)

        for klass in default_classes:
            opener.add_handler(klass())

        for h in handlers:
            if is_class(h):
                h = h()
            opener.add_handler(h)
        return opener

    class BaseHandler:
        handler_order = 500

        def add_parent(self, parent):
            self.parent = parent

        def close(self):
            # Only exists for backwards compatibility
            pass

        def __lt__(self, other):
            return self.handler_order < getattr(
                    other, 'handler_order', sys.maxsize)

        def __copy__(self):
            return self.__class__()

    class HTTPErrorProcessor(BaseHandler):
        """Process HTTP error responses.

        The purpose of this handler is to to allow other response processors a
        look-in by removing the call to parent.error() from
        AbstractHTTPHandler.

        For non-2xx error codes, this just passes the job on to the
        Handler.<proto>_error_<code> methods, via the OpenerDirector.error method.
        Eventually, HTTPDefaultErrorHandler will raise an HTTPError if no other
        handler handles the error.

        """
        handler_order = 1000  # after all other processors

        def http_response(self, request, response):
            code, msg, hdrs = response.code, response.msg, response.info()

            # According to RFC 2616, "2xx" code indicates that the client's
            # request was successfully received, understood, and accepted.
            if not (200 <= code < 300):
                # hardcoded http is NOT a bug
                response = self.parent.error(
                    'http', request, response, code, msg, hdrs)

            return response

        https_response = http_response

    class HTTPDefaultErrorHandler(BaseHandler):

        def http_error_default(self, req, fp, code, msg, hdrs):
            # why these error methods took the code, msg, headers args in the first
            # place rather than a response object, I don't know, but to avoid
            # multiple wrapping, we're discarding them

            if isinstance(fp, HTTPError):
                response = fp
            else:
                response = HTTPError(
                    req.get_full_url(), code, msg, hdrs, fp)
            assert code == response.code
            assert msg == response.msg
            assert hdrs == response.hdrs
            raise response

    class HTTPRedirectHandler(BaseHandler):
        # maximum number of redirections to any single URL
        # this is needed because of the state that cookies introduce
        max_repeats = 4
        # maximum total number of redirections (regardless of URL) before
        # assuming we're in a loop
        max_redirections = 10

        # Implementation notes:

        # To avoid the server sending us into an infinite loop, the request
        # object needs to track what URLs we have already seen.  Do this by
        # adding a handler-specific attribute to the Request object.  The value
        # of the dict is used to count the number of times the same URL has
        # been visited.  This is needed because visiting the same URL twice
        # does not necessarily imply a loop, thanks to state introduced by
        # cookies.

        # Always unhandled redirection codes:
        # 300 Multiple Choices: should not handle this here.
        # 304 Not Modified: no need to handle here: only of interest to caches
        #     that do conditional GETs
        # 305 Use Proxy: probably not worth dealing with here
        # 306 Unused: what was this for in the previous versions of protocol??

        def redirect_request(self, req, fp, code, msg, headers, newurl):
            """Return a Request or None in response to a redirect.

            This is called by the http_error_30x methods when a
            redirection response is received.  If a redirection should
            take place, return a new Request to allow http_error_30x to
            perform the redirect.  Otherwise, raise HTTPError if no-one
            else should try to handle this url.  Return None if you can't
            but another Handler might.
            """
            from ._request import Request
            m = req.get_method()
            if (code in (301, 302, 303, 307, "refresh") and m in ("GET", "HEAD")
                    or code in (301, 302, 303, "refresh") and m == "POST"):
                # Strictly (according to RFC 2616), 301 or 302 in response
                # to a POST MUST NOT cause a redirection without confirmation
                # from the user (of urllib2, in this case).  In practice,
                # essentially all clients do redirect in this case, so we do
                # the same.
                # TODO: really refresh redirections should be visiting; tricky to
                # fix
                new = Request(
                    newurl,
                    headers=req.headers,
                    origin_req_host=req.get_origin_req_host(),
                    unverifiable=True,
                    visit=False,
                    timeout=req.timeout)
                new._origin_req = getattr(req, "_origin_req", req)
                return new
            else:
                raise HTTPError(req.get_full_url(), code, msg, headers, fp)

        def http_error_302(self, req, fp, code, msg, headers):
            # Some servers (incorrectly) return multiple Location headers
            # (so probably same goes for URI).  Use first header.
            if 'location' in headers:
                newurl = headers.getheaders('location')[0]
            elif 'uri' in headers:
                newurl = headers.getheaders('uri')[0]
            else:
                return
            newurl = _rfc3986.clean_url(newurl)
            newurl = _rfc3986.urljoin(req.get_full_url(), newurl)

            # XXX Probably want to forget about the state of the current
            # request, although that might interact poorly with other
            # handlers that also use handler-specific request attributes
            new = self.redirect_request(req, fp, code, msg, headers, newurl)
            if new is None:
                return

            # loop detection
            # .redirect_dict has a key url if url was previously visited.
            if hasattr(req, 'redirect_dict'):
                visited = new.redirect_dict = req.redirect_dict
                if (visited.get(newurl, 0) >= self.max_repeats or
                        len(visited) >= self.max_redirections):
                    raise HTTPError(req.get_full_url(), code,
                                    self.inf_msg + msg, headers, fp)
            else:
                visited = new.redirect_dict = req.redirect_dict = {}
            visited[newurl] = visited.get(newurl, 0) + 1

            # Don't close the fp until we are sure that we won't use it
            # with HTTPError.
            fp.read()
            fp.close()

            return self.parent.open(new)

        http_error_301 = http_error_303 = http_error_307 = http_error_302
        http_error_refresh = http_error_302

        inf_msg = "The HTTP server returned a redirect error that would " \
                  "lead to an infinite loop.\n" \
                  "The last 30x error message was:\n"

    def _parse_proxy(proxy):
        """Return (scheme, user, password, host/port) given a URL or an authority.

        If a URL is supplied, it must have an authority (host:port) component.
        According to RFC 3986, having an authority component means the URL must
        have two slashes after the scheme:

        >>> _parse_proxy('file:/ftp.example.com/')
        Traceback (most recent call last):
        ValueError: proxy URL with no authority: 'file:/ftp.example.com/'

        The first three items of the returned tuple may be None.

        Examples of authority parsing:

        >>> _parse_proxy('proxy.example.com')
        (None, None, None, 'proxy.example.com')
        >>> _parse_proxy('proxy.example.com:3128')
        (None, None, None, 'proxy.example.com:3128')

        The authority component may optionally include userinfo (assumed to be
        username:password):

        >>> _parse_proxy('joe:password@proxy.example.com')
        (None, 'joe', 'password', 'proxy.example.com')
        >>> _parse_proxy('joe:password@proxy.example.com:3128')
        (None, 'joe', 'password', 'proxy.example.com:3128')

        Same examples, but with URLs instead:

        >>> _parse_proxy('http://proxy.example.com/')
        ('http', None, None, 'proxy.example.com')
        >>> _parse_proxy('http://proxy.example.com:3128/')
        ('http', None, None, 'proxy.example.com:3128')
        >>> _parse_proxy('http://joe:password@proxy.example.com/')
        ('http', 'joe', 'password', 'proxy.example.com')
        >>> _parse_proxy('http://joe:password@proxy.example.com:3128')
        ('http', 'joe', 'password', 'proxy.example.com:3128')

        Everything after the authority is ignored:

        >>> _parse_proxy('ftp://joe:password@proxy.example.com/rubbish:3128')
        ('ftp', 'joe', 'password', 'proxy.example.com')

        Test for no trailing '/' case:

        >>> _parse_proxy('http://joe:password@proxy.example.com')
        ('http', 'joe', 'password', 'proxy.example.com')

        """
        scheme, r_scheme = splittype(proxy)
        if not r_scheme.startswith("/"):
            # authority
            scheme = None
            authority = proxy
        else:
            # URL
            if not r_scheme.startswith("//"):
                raise ValueError("proxy URL with no authority: %r" % proxy)
            # We have an authority, so for RFC 3986-compliant URLs (by ss 3.
            # and 3.3.), path is empty or starts with '/'
            end = r_scheme.find("/", 2)
            if end == -1:
                end = None
            authority = r_scheme[2:end]
        userinfo, hostport = splituser(authority)
        if userinfo is not None:
            user, password = splitpasswd(userinfo)
        else:
            user = password = None
        return scheme, user, password, hostport

    class ProxyHandler(BaseHandler):
        # Proxies must be in front
        handler_order = 100

        def __init__(self, proxies=None, proxy_bypass=None):
            if proxies is None:
                proxies = getproxies()

            assert is_mapping(proxies), "proxies must be a mapping"
            self.proxies = proxies
            for type, url in iteritems(proxies):
                setattr(self, '%s_open' % type,
                        lambda r, proxy=url, type=type, meth=self.proxy_open:
                        meth(r, proxy, type))
            if proxy_bypass is None:
                proxy_bypass = urllib_proxy_bypass
            self._proxy_bypass = proxy_bypass

        def proxy_open(self, req, proxy, type):
            orig_type = req.get_type()
            proxy_type, user, password, hostport = _parse_proxy(proxy)

            if proxy_type is None:
                proxy_type = orig_type

            if req.get_host() and self._proxy_bypass(req.get_host()):
                return None

            if user and password:
                user_pass = '%s:%s' % (unquote(user), unquote(password))
                if not isinstance(user_pass, bytes):
                    user_pass = user_pass.encode('utf-8')
                creds = base64.b64encode(user_pass).strip()
                if isinstance(creds, bytes):
                    creds = creds.decode('ascii')
                req.add_header('Proxy-authorization', 'Basic ' + creds)
            hostport = unquote(hostport)
            req.set_proxy(hostport, proxy_type)
            if orig_type == proxy_type or orig_type == 'https':
                # let other handlers take care of it
                return None
            else:
                # need to start over, because the other handlers don't
                # grok the proxy's URL type
                # e.g. if we have a constructor arg proxies like so:
                # {'http': 'ftp://proxy.example.com'}, we may end up turning
                # a request for http://acme.example.com/a into one for
                # ftp://proxy.example.com/a
                return self.parent.open(req)

        def __copy__(self):
            return ProxyHandler(self.proxies.copy(), self._proxy_bypass)

    class HTTPPasswordMgr:

        def __init__(self):
            self.passwd = {}

        def add_password(self, realm, uri, user, passwd):
            # uri could be a single URI or a sequence
            if is_string(uri):
                uri = [uri]
            if realm not in self.passwd:
                self.passwd[realm] = {}
            for default_port in True, False:
                reduced_uri = tuple(
                    [self.reduce_uri(u, default_port) for u in uri])
                self.passwd[realm][reduced_uri] = (user, passwd)

        def find_user_password(self, realm, authuri):
            domains = self.passwd.get(realm, {})
            for default_port in True, False:
                reduced_authuri = self.reduce_uri(authuri, default_port)
                for uris, authinfo in iteritems(domains):
                    for uri in uris:
                        if self.is_suburi(uri, reduced_authuri):
                            return authinfo
            return None, None

        def reduce_uri(self, uri, default_port=True):
            """Accept authority or URI and extract only the authority and path."""
            # note HTTP URLs do not have a userinfo component
            parts = urlsplit(uri)
            if parts[1]:
                # URI
                scheme = parts[0]
                authority = parts[1]
                path = parts[2] or '/'
            else:
                # host or host:port
                scheme = None
                authority = uri
                path = '/'
            host, port = splitport(authority)
            if default_port and port is None and scheme is not None:
                dport = {"http": 80,
                         "https": 443,
                         }.get(scheme)
                if dport is not None:
                    authority = "%s:%d" % (host, dport)
            return authority, path

        def is_suburi(self, base, test):
            """Check if test is below base in a URI tree

            Both args must be URIs in reduced form.
            """
            if base == test:
                return True
            if base[0] != test[0]:
                return False
            common = posixpath.commonprefix((base[1], test[1]))
            if len(common) == len(base[1]):
                return True
            return False

        def __copy__(self):
            ans = self.__class__()
            ans.passwd = copy.deepcopy(self.passwd)
            return ans

    class HTTPPasswordMgrWithDefaultRealm(HTTPPasswordMgr):

        def find_user_password(self, realm, authuri):
            user, password = HTTPPasswordMgr.find_user_password(self, realm,
                                                                authuri)
            if user is not None:
                return user, password
            return HTTPPasswordMgr.find_user_password(self, None, authuri)

    class AbstractBasicAuthHandler:

        # XXX this allows for multiple auth-schemes, but will stupidly pick
        # the last one with a realm specified.

        # allow for double- and single-quoted realm values
        # (single quotes are a violation of the RFC, but appear in the wild)
        rx = re.compile('(?:.*,)*[ \t]*([^ \t]+)[ \t]+'
                        'realm=(["\'])(.*?)\\2', re.I)

        # XXX could pre-emptively send auth info already accepted (RFC 2617,
        # end of section 2, and section 1.2 immediately after "credentials"
        # production).

        def __init__(self, password_mgr=None):
            if password_mgr is None:
                password_mgr = HTTPPasswordMgr()
            self.passwd = password_mgr
            self.add_password = self.passwd.add_password

        def http_error_auth_reqed(self, authreq, host, req, headers):
            # host may be an authority (without userinfo) or a URL with an
            # authority
            # XXX could be multiple headers
            authreq = headers.get(authreq, None)
            if authreq:
                mo = AbstractBasicAuthHandler.rx.search(authreq)
                if mo:
                    scheme, quote, realm = mo.groups()
                    if scheme.lower() == 'basic':
                        return self.retry_http_basic_auth(host, req, realm)

        def retry_http_basic_auth(self, host, req, realm):
            user, pw = self.passwd.find_user_password(realm, host)
            if pw is not None:
                raw = "%s:%s" % (user, pw)
                auth = str('Basic %s' % base64.b64encode(
                        raw.encode('utf-8')).strip().decode('ascii'))
                if req.get_header(self.auth_header, None) == auth:
                    return None
                newreq = copy.copy(req)
                newreq.add_header(self.auth_header, auth)
                newreq.visit = False
                return self.parent.open(newreq)
            else:
                return None

        def __copy__(self):
            return self.__class__(self.passwd.__copy__())

    class HTTPBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):

        auth_header = 'Authorization'

        def http_error_401(self, req, fp, code, msg, headers):
            url = req.get_full_url()
            return self.http_error_auth_reqed('www-authenticate',
                                              url, req, headers)

        def __copy__(self):
            return AbstractBasicAuthHandler.__copy__(self)

    class ProxyBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):

        auth_header = 'Proxy-authorization'

        def http_error_407(self, req, fp, code, msg, headers):
            # http_error_auth_reqed requires that there is no userinfo component in
            # authority.  Assume there isn't one, since urllib2 does not (and
            # should not, RFC 3986 s. 3.2.1) support requests for URLs containing
            # userinfo.
            authority = req.get_host()
            return self.http_error_auth_reqed('proxy-authenticate',
                                              authority, req, headers)

        def __copy__(self):
            return AbstractBasicAuthHandler.__copy__(self)

    randombytes = os.urandom

    class AbstractDigestAuthHandler:
        # Digest authentication is specified in RFC 2617.

        # XXX The client does not inspect the Authentication-Info header
        # in a successful response.

        # XXX It should be possible to test this implementation against
        # a mock server that just generates a static set of challenges.

        # XXX qop="auth-int" supports is shaky

        def __init__(self, passwd=None):
            if passwd is None:
                passwd = HTTPPasswordMgr()
            self.passwd = passwd
            self.add_password = self.passwd.add_password
            self.retried = 0
            self.nonce_count = 0
            self.last_nonce = None

        def reset_retry_count(self):
            self.retried = 0

        def http_error_auth_reqed(self, auth_header, host, req, headers):
            authreq = headers.get(auth_header, None)
            if self.retried > 5:
                # Don't fail endlessly - if we failed once, we'll probably
                # fail a second time. Hm. Unless the Password Manager is
                # prompting for the information. Crap. This isn't great
                # but it's better than the current 'repeat until recursion
                # depth exceeded' approach <wink>
                raise HTTPError(req.get_full_url(), 401, "digest auth failed",
                                headers, None)
            else:
                self.retried += 1
            if authreq:
                scheme = authreq.split()[0]
                if scheme.lower() == 'digest':
                    return self.retry_http_digest_auth(req, authreq)

        def retry_http_digest_auth(self, req, auth):
            token, challenge = auth.split(' ', 1)
            chal = parse_keqv_list(parse_http_list(challenge))
            auth = self.get_authorization(req, chal)
            if auth:
                auth_val = 'Digest %s' % auth
                if req.get_header(self.auth_header, None) == auth_val:
                    return None
                newreq = copy.copy(req)
                newreq.add_unredirected_header(self.auth_header, auth_val)
                newreq.visit = False
                return self.parent.open(newreq)

        def get_cnonce(self, nonce):
            # The cnonce-value is an opaque
            # quoted string value provided by the client and used by both client
            # and server to avoid chosen plaintext attacks, to provide mutual
            # authentication, and to provide some message integrity protection.
            # This isn't a fabulous effort, but it's probably Good Enough.
            dig = sha1_digest("%s:%s:%s:%s" % (self.nonce_count, nonce,
                                               time.ctime(), randombytes(8)))
            return dig[:16]

        def get_authorization(self, req, chal):
            try:
                realm = chal['realm']
                nonce = chal['nonce']
                qop = chal.get('qop')
                algorithm = chal.get('algorithm', 'MD5')
                # mod_digest doesn't send an opaque, even though it isn't
                # supposed to be optional
                opaque = chal.get('opaque', None)
            except KeyError:
                return None

            H, KD = self.get_algorithm_impls(algorithm)
            if H is None:
                return None

            user, pw = self.passwd.find_user_password(realm, req.get_full_url())
            if user is None:
                return None

            # XXX not implemented yet
            if req.has_data():
                entdig = self.get_entity_digest(req.get_data(), chal)
            else:
                entdig = None

            A1 = "%s:%s:%s" % (user, realm, pw)
            A2 = "%s:%s" % (req.get_method(),
                            # XXX selector: what about proxies and full urls
                            req.get_selector())
            if qop == 'auth':
                if nonce == self.last_nonce:
                    self.nonce_count += 1
                else:
                    self.nonce_count = 1
                    self.last_nonce = nonce

                ncvalue = '%08x' % self.nonce_count
                cnonce = self.get_cnonce(nonce)
                noncebit = "%s:%s:%s:%s:%s" % (nonce, ncvalue, cnonce, qop, H(A2))
                respdig = KD(H(A1), noncebit)
            elif qop is None:
                respdig = KD(H(A1), "%s:%s" % (nonce, H(A2)))
            else:
                # XXX handle auth-int.
                logger = logging.getLogger("mechanize.auth")
                logger.info("digest auth auth-int qop is not supported, not "
                            "handling digest authentication")
                return None

            # XXX should the partial digests be encoded too?

            base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \
                   'response="%s"' % (user, realm, nonce, req.get_selector(),
                                      respdig)
            if opaque:
                base += ', opaque="%s"' % opaque
            if entdig:
                base += ', digest="%s"' % entdig
            base += ', algorithm="%s"' % algorithm
            if qop:
                base += ', qop=auth, nc=%s, cnonce="%s"' % (ncvalue, cnonce)
            return base

        def get_algorithm_impls(self, algorithm):
            # algorithm should be case-insensitive according to RFC2617
            algorithm = algorithm.upper()
            if algorithm == 'MD5':
                H = md5_digest
            elif algorithm == 'SHA':
                H = sha1_digest
            # XXX MD5-sess
            KD = lambda s, d: H("%s:%s" % (s, d))  # noqa
            return H, KD

        def get_entity_digest(self, data, chal):
            # XXX not implemented yet
            return None

        def __copy__(self):
            return self.__class__(self.passwd.__copy__())

    class HTTPDigestAuthHandler(BaseHandler, AbstractDigestAuthHandler):
        """An authentication protocol defined by RFC 2069

        Digest authentication improves on basic authentication because it
        does not transmit passwords in the clear.
        """

        auth_header = 'Authorization'
        handler_order = 490  # before Basic auth

        def http_error_401(self, req, fp, code, msg, headers):
            host = urlparse(req.get_full_url())[1]
            retry = self.http_error_auth_reqed('www-authenticate',
                                               host, req, headers)
            self.reset_retry_count()
            return retry

        def __copy__(self):
            return AbstractDigestAuthHandler.__copy__(self)

    class ProxyDigestAuthHandler(BaseHandler, AbstractDigestAuthHandler):

        auth_header = 'Proxy-Authorization'
        handler_order = 490  # before Basic auth

        def http_error_407(self, req, fp, code, msg, headers):
            host = req.get_host()
            retry = self.http_error_auth_reqed('proxy-authenticate',
                                               host, req, headers)
            self.reset_retry_count()
            return retry

        def __copy__(self):
            return AbstractDigestAuthHandler.__copy__(self)

    class AbstractHTTPHandler(BaseHandler):

        def __init__(self, debuglevel=0):
            self._debuglevel = debuglevel

        def set_http_debuglevel(self, level):
            self._debuglevel = level

        def do_request_(self, request):
            host = request.get_host()
            if not host:
                raise URLError('no host given')

            if request.has_data():  # POST
                data = request.get_data()
                if not request.has_header('Content-type'):
                    request.add_unredirected_header(
                        'Content-type',
                        'application/x-www-form-urlencoded')
                if not request.has_header('Content-length'):
                    request.add_unredirected_header(
                        'Content-length', '%d' % len(data))

            sel_host = host
            if request.has_proxy():
                scheme, sel = splittype(request.get_selector())
                sel_host, sel_path = splithost(sel)

            for name, value in self.parent.addheaders:
                name = name.capitalize()
                if not request.has_header(name):
                    request.add_unredirected_header(name, value)
            if not request.has_header('Host'):
                request.add_unredirected_header('Host', sel_host)

            return request

        def do_open(self, http_class, req):
            """Return an addinfourl object for the request, using http_class.

            http_class must implement the HTTPConnection API from httplib.
            The addinfourl return value is a file-like object.  It also
            has methods and attributes including:
                - info(): return a HTTPMessage object for the headers
                - geturl(): return the original request URL
                - code: HTTP status code
            """
            host_port = req.get_host()
            if not host_port:
                raise URLError('no host given')

            h = http_class(host_port, timeout=req.timeout)
            h.set_debuglevel(self._debuglevel)

            headers = OrderedDict(req.headers)
            for key, val in iteritems(req.unredirected_hdrs):
                headers[key] = val
            # We want to make an HTTP/1.1 request, but the addinfourl
            # class isn't prepared to deal with a persistent connection.
            # It will try to read all remaining data from the socket,
            # which will block while the server waits for the next request.
            # So make sure the connection gets closed after the (only)
            # request.
            headers["Connection"] = "close"
            # httplib in python 2 needs str() not unicode() for all request
            # parameters
            if is_py2:
                headers = OrderedDict(
                        (str(name.title()), str(val))
                        for name, val in iteritems(headers))
            else:
                headers = OrderedDict(
                        (as_unicode(name, 'iso-8859-1').title(),
                         as_unicode(val, 'iso-8859-1'))
                        for name, val in iteritems(headers))

            if req._tunnel_host:
                set_tunnel = h.set_tunnel if hasattr(
                    h, "set_tunnel") else h._set_tunnel
                tunnel_headers = {}
                proxy_auth_hdr = "Proxy-Authorization"
                if proxy_auth_hdr in headers:
                    tunnel_headers[proxy_auth_hdr] = headers[proxy_auth_hdr]
                    # Proxy-Authorization should not be sent to origin server.
                    del headers[proxy_auth_hdr]
                set_tunnel(req._tunnel_host, headers=tunnel_headers)

            if self.parent.finalize_request_headers is not None:
                self.parent.finalize_request_headers(req, headers)

            try:
                h.request(str(req.get_method()), str(req.get_selector()), req.data,
                          headers)
                r = h.getresponse()
            except socket.error as err:  # XXX what error?
                raise URLError(err)

            # Pick apart the HTTPResponse object to get the addinfourl
            # object initialized properly.
            fp = create_readline_wrapper(r)

            resp = closeable_response(
                fp, r.msg, req.get_full_url(), r.status, r.reason,
                getattr(r, 'version', None))
            return resp

        def __copy__(self):
            return self.__class__(self._debuglevel)

    class HTTPHandler(AbstractHTTPHandler):

        def http_open(self, req):
            return self.do_open(HTTPConnection, req)

        http_request = AbstractHTTPHandler.do_request_

    class HTTPSHandler(AbstractHTTPHandler):

        def __init__(self, client_cert_manager=None):
            AbstractHTTPHandler.__init__(self)
            self.client_cert_manager = client_cert_manager
            self.ssl_context = None

        def https_open(self, req):
            key_file = cert_file = None
            if self.client_cert_manager is not None:
                key_file, cert_file = self.client_cert_manager.find_key_cert(
                    req.get_full_url())
            if self.ssl_context is None:
                conn_factory = partial(
                    HTTPSConnection, key_file=key_file,
                    cert_file=cert_file)
            else:
                conn_factory = partial(
                    HTTPSConnection, key_file=key_file,
                    cert_file=cert_file, context=self.ssl_context)
            return self.do_open(conn_factory, req)

        https_request = AbstractHTTPHandler.do_request_

        def __copy__(self):
            ans = self.__class__(self.client_cert_manager)
            ans._debuglevel = self._debuglevel
            ans.ssl_context = self.ssl_context
            return ans

    class HTTPCookieProcessor(BaseHandler):
        """Handle HTTP cookies.

        Public attributes:

        cookiejar: CookieJar instance

        """

        def __init__(self, cookiejar=None):
            if cookiejar is None:
                cookiejar = CookieJar()
            self.cookiejar = cookiejar

        def http_request(self, request):
            self.cookiejar.add_cookie_header(request)
            return request

        def http_response(self, request, response):
            self.cookiejar.extract_cookies(response, request)
            return response

        def __copy__(self):
            return self.__class__(self.cookiejar)

        https_request = http_request
        https_response = http_response

    class UnknownHandler(BaseHandler):

        def unknown_open(self, req):
            type = req.get_type()
            raise URLError('unknown url type: %s' % type)

    def parse_keqv_list(ln):
        """Parse list of key=value strings where keys are not duplicated."""
        parsed = {}
        for elt in ln:
            k, v = elt.split('=', 1)
            if v[0:1] == '"' and v[-1:] == '"':
                v = v[1:-1]
            parsed[k] = v
        return parsed

    def parse_http_list(s):
        """Parse lists as described by RFC 2068 Section 2.

        In particular, parse comma-separated lists where the elements of
        the list may include quoted-strings.  A quoted-string could
        contain a comma.  A non-quoted string could have quotes in the
        middle.  Neither commas nor quotes count if they are escaped.
        Only double-quotes count, not single-quotes.
        """
        res = []
        part = ''

        escape = quote = False
        for cur in s:
            if escape:
                part += cur
                escape = False
                continue
            if quote:
                if cur == '\\':
                    escape = True
                    continue
                elif cur == '"':
                    quote = False
                part += cur
                continue

            if cur == ',':
                res.append(part)
                part = ''
                continue

            if cur == '"':
                quote = True

            part += cur

        # append last part
        if part:
            res.append(part)

        return list(filter(None, (part_.strip() for part_ in res)))

    class FileHandler(BaseHandler):
        # Use local file or FTP depending on form of URL

        def file_open(self, req):
            url = req.get_selector()
            if url[:2] == '//' and url[2:3] != '/':
                req.type = 'ftp'
                return self.parent.open(req)
            else:
                return self.open_local_file(req)

        # names for the localhost
        names = None

        def get_names(self):
            if FileHandler.names is None:
                try:
                    FileHandler.names = (socket.gethostbyname('localhost'),
                                         socket.gethostbyname(socket.gethostname())
                                         )
                except socket.gaierror:
                    FileHandler.names = (socket.gethostbyname('localhost'),)
            return FileHandler.names

        # not entirely sure what the rules are here
        def open_local_file(self, req):
            import email.utils as emailutils
            import mimetypes
            host = req.get_host()
            file = req.get_selector()
            try:
                localfile = url2pathname(file)
            except IOError as err:
                # url2pathname raises this on windows for bad urls
                raise URLError(err)
            try:
                stats = os.stat(localfile)
                size = stats.st_size
                modified = emailutils.formatdate(stats.st_mtime, usegmt=True)
                mtype = mimetypes.guess_type(file)[0]
                headers = create_response_info(BytesIO(
                    ('Content-type: %s\nContent-length: %d\nLast-modified: %s\n' %
                        (mtype or 'text/plain', size, modified)).encode(
                            'iso-8859-1')))
                if host:
                    host, port = splitport(host)
                if not host or (
                        not port and socket.gethostbyname(host) in self.get_names()
                ):
                    fp = open(localfile, 'rb')
                    return closeable_response(fp, headers, 'file:' + file)
            except OSError as msg:
                # urllib2 users shouldn't expect OSErrors coming from urlopen()
                raise URLError(msg)
            raise URLError('file not on local host')

    class FTPHandler(BaseHandler):

        def ftp_open(self, req):
            import ftplib
            import mimetypes
            host = req.get_host()
            if not host:
                raise URLError('ftp error: no host given')
            host, port = splitport(host)
            if port is None:
                port = ftplib.FTP_PORT
            else:
                port = int(port)

            # username/password handling
            user, host = splituser(host)
            if user:
                user, passwd = splitpasswd(user)
            else:
                passwd = None
            host = unquote(host)
            user = unquote(user or '')
            passwd = unquote(passwd or '')

            try:
                host = socket.gethostbyname(host)
            except socket.error as msg:
                raise URLError(msg)
            path, attrs = splitattr(req.get_selector())
            dirs = path.split('/')
            dirs = list(map(unquote, dirs))
            dirs, file = dirs[:-1], dirs[-1]
            if dirs and not dirs[0]:
                dirs = dirs[1:]
            try:
                fw = self.connect_ftp(user, passwd, host, port, dirs, req.timeout)
                type = file and 'I' or 'D'
                for attr in attrs:
                    attr, value = splitvalue(attr)
                    if attr.lower() == 'type' and \
                       value in ('a', 'A', 'i', 'I', 'd', 'D'):
                        type = value.upper()
                fp, retrlen = fw.retrfile(file, type)
                headers = ""
                mtype = mimetypes.guess_type(req.get_full_url())[0]
                if mtype:
                    headers += "Content-type: %s\n" % mtype
                if retrlen is not None and retrlen >= 0:
                    headers += "Content-length: %d\n" % retrlen
                sf = BytesIO(headers.encode('iso-8859-1'))
                headers = create_response_info(sf)
                return closeable_response(fp, headers, req.get_full_url())
            except ftplib.all_errors as msg:
                raise_with_traceback(URLError('ftp error: %s' % msg))

        def connect_ftp(self, user, passwd, host, port, dirs, timeout):
            try:
                fw = ftpwrapper(user, passwd, host, port, dirs, timeout)
            except TypeError:
                # Python < 2.6, no per-connection timeout support
                fw = ftpwrapper(user, passwd, host, port, dirs)
    # fw.ftp.set_debuglevel(1)
            return fw

    class CacheFTPHandler(FTPHandler):
        # XXX would be nice to have pluggable cache strategies
        # XXX this stuff is definitely not thread safe

        def __init__(self):
            self.cache = {}
            self.timeout = {}
            self.soonest = 0
            self.delay = 60
            self.max_conns = 16

        def setTimeout(self, t):
            self.delay = t

        def setMaxConns(self, m):
            self.max_conns = m

        def connect_ftp(self, user, passwd, host, port, dirs, timeout):
            key = user, host, port, '/'.join(dirs), timeout
            if key in self.cache:
                self.timeout[key] = time.time() + self.delay
            else:
                self.cache[key] = ftpwrapper(
                    user, passwd, host, port, dirs, timeout)
                self.timeout[key] = time.time() + self.delay
            self.check_cache()
            return self.cache[key]

        def check_cache(self):
            # first check for old ones
            t = time.time()
            if self.soonest <= t:
                for k, v in iteritems(self.timeout):
                    if v < t:
                        self.cache[k].close()
                        del self.cache[k]
                        del self.timeout[k]
            self.soonest = min(self.timeout.values())

            # then check the size
            if len(self.cache) == self.max_conns:
                for k, v in iteritems(self.timeout):
                    if v == self.soonest:
                        del self.cache[k]
                        del self.timeout[k]
                        break
                self.soonest = min(self.timeout.values())