traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
cpython/Lib/urllib/request.py

2500 lines
88 KiB
Python
Raw Blame History

"""An extensible library for opening URLs using a variety of protocols
The simplest way to use this module is to call the urlopen function,
which accepts a string containing a URL or a Request object (described
below). It opens the URL and returns the results as file-like
object; the returned object has some extra methods described below.
The OpenerDirector manages a collection of Handler objects that do
all the actual work. Each Handler implements a particular protocol or
option. The OpenerDirector is a composite object that invokes the
Handlers needed to open the requested URL. For example, the
HTTPHandler performs HTTP GET and POST requests and deals with
non-error returns. The HTTPRedirectHandler automatically deals with
HTTP 301, 302, 303 and 307 redirect errors, and the HTTPDigestAuthHandler
deals with digest authentication.
urlopen(url, data=None) -- Basic usage is the same as original
urllib. pass the url and optionally data to post to an HTTP URL, and
get a file-like object back. One difference is that you can also pass
a Request instance instead of URL. Raises a URLError (subclass of
IOError); for HTTP errors, raises an HTTPError, which can also be
treated as a valid response.
build_opener -- Function that creates a new OpenerDirector instance.
Will install the default handlers. Accepts one or more Handlers as
arguments, either instances or Handler classes that it will
instantiate. If one of the argument is a subclass of the default
handler, the argument will be installed instead of the default.
install_opener -- Installs a new opener as the default opener.
objects of interest:
OpenerDirector -- Sets up the User Agent as the Python-urllib client and manages
the Handler classes, while dealing with requests and responses.
Request -- An object that encapsulates the state of a request. The
state can be as simple as the URL. It can also include extra HTTP
headers, e.g. a User-Agent.
BaseHandler --
internals:
BaseHandler and parent
_call_chain conventions
Example usage:
import urllib.request
# set up authentication info
authinfo = urllib.request.HTTPBasicAuthHandler()
authinfo.add_password(realm='PDQ Application',
uri='https://mahler:8092/site-updates.py',
user='klem',
passwd='geheim$parole')
proxy_support = urllib.request.ProxyHandler({"http" : "http://ahad-haam:3128"})
# build a new opener that adds authentication and caching FTP handlers
opener = urllib.request.build_opener(proxy_support, authinfo,
urllib.request.CacheFTPHandler)
# install it
urllib.request.install_opener(opener)
f = urllib.request.urlopen('http://www.python.org/')
"""
# 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
import base64
import bisect
import email
import hashlib
import http.client
import io
import os
import posixpath
import random
import re
import socket
import sys
import time
import collections
from urllib.error import URLError, HTTPError, ContentTooShortError
from urllib.parse import (
urlparse, urlsplit, urljoin, unwrap, quote, unquote,
splittype, splithost, splitport, splituser, splitpasswd,
splitattr, splitquery, splitvalue, splittag, to_bytes, urlunparse)
from urllib.response import addinfourl, addclosehook
# check for SSL
try:
import ssl
except ImportError:
_have_ssl = False
else:
_have_ssl = True
# used in User-Agent header sent
__version__ = sys.version[:3]
_opener = None
def urlopen(url, data=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
*, cafile=None, capath=None):
global _opener
if cafile or capath:
if not _have_ssl:
raise ValueError('SSL support not available')
context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
context.options |= ssl.OP_NO_SSLv2
if cafile or capath:
context.verify_mode = ssl.CERT_REQUIRED
context.load_verify_locations(cafile, capath)
check_hostname = True
else:
check_hostname = False
https_handler = HTTPSHandler(context=context, check_hostname=check_hostname)
opener = build_opener(https_handler)
elif _opener is None:
_opener = opener = build_opener()
else:
opener = _opener
return opener.open(url, data, timeout)
def install_opener(opener):
global _opener
_opener = opener
# TODO(jhylton): Make this work with the same global opener.
_urlopener = None
def urlretrieve(url, filename=None, reporthook=None, data=None):
global _urlopener
if not _urlopener:
_urlopener = FancyURLopener()
return _urlopener.retrieve(url, filename, reporthook, data)
def urlcleanup():
if _urlopener:
_urlopener.cleanup()
global _opener
if _opener:
_opener = None
# copied from cookielib.py
_cut_port_re = re.compile(r":\d+$", re.ASCII)
def request_host(request):
"""Return request-host, as defined by RFC 2965.
Variation from RFC: returned value is lowercased, for convenient
comparison.
"""
url = request.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()
class Request:
def __init__(self, url, data=None, headers={},
origin_req_host=None, unverifiable=False):
# unwrap('<URL:type://host/path>') --> 'type://host/path'
self.full_url = unwrap(url)
self.full_url, self.fragment = splittag(self.full_url)
self.data = data
self.headers = {}
self._tunnel_host = None
for key, value in headers.items():
self.add_header(key, value)
self.unredirected_hdrs = {}
if origin_req_host is None:
origin_req_host = request_host(self)
self.origin_req_host = origin_req_host
self.unverifiable = unverifiable
self._parse()
def _parse(self):
self.type, rest = splittype(self.full_url)
if self.type is None:
raise ValueError("unknown url type: %s" % self.full_url)
self.host, self.selector = splithost(rest)
if self.host:
self.host = unquote(self.host)
def get_method(self):
if self.data is not None:
return "POST"
else:
return "GET"
# Begin deprecated methods
def add_data(self, data):
self.data = data
def has_data(self):
return self.data is not None
def get_data(self):
return self.data
def get_full_url(self):
if self.fragment:
return '%s#%s' % (self.full_url, self.fragment)
else:
return self.full_url
def get_type(self):
return self.type
def get_host(self):
return self.host
def get_selector(self):
return self.selector
def is_unverifiable(self):
return self.unverifiable
def get_origin_req_host(self):
return self.origin_req_host
# End deprecated methods
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.selector = self.full_url
self.host = host
def has_proxy(self):
return self.selector == self.full_url
def add_header(self, key, val):
# useful for something like authentication
self.headers[key.capitalize()] = val
def add_unredirected_header(self, key, val):
# will not be added to a redirected request
self.unredirected_hdrs[key.capitalize()] = val
def has_header(self, header_name):
return (header_name in self.headers or
header_name in self.unredirected_hdrs)
def get_header(self, header_name, default=None):
return self.headers.get(
header_name,
self.unredirected_hdrs.get(header_name, default))
def header_items(self):
hdrs = self.unredirected_hdrs.copy()
hdrs.update(self.headers)
return list(hdrs.items())
class OpenerDirector:
def __init__(self):
client_version = "Python-urllib/%s" % __version__
self.addheaders = [('User-agent', client_version)]
# self.handlers is retained only for backward compatibility
self.handlers = []
# manage the individual 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:
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, fullurl, data=None, timeout=socket._GLOBAL_DEFAULT_TIMEOUT):
# accept a URL or a Request object
if isinstance(fullurl, str):
req = Request(fullurl, data)
else:
req = fullurl
if data is not None:
req.data = data
req.timeout = timeout
protocol = req.type
# pre-process request
meth_name = protocol+"_request"
for processor in self.process_request.get(protocol, []):
meth = getattr(processor, meth_name)
req = meth(req)
response = self._open(req, data)
# post-process response
meth_name = protocol+"_response"
for processor in self.process_response.get(protocol, []):
meth = getattr(processor, meth_name)
response = meth(req, response)
return response
def _open(self, req, data=None):
result = self._call_chain(self.handle_open, 'default',
'default_open', req)
if result:
return result
protocol = req.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
dict = self.handle_error['http'] # https is not different than 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.
"""
def isclass(obj):
return isinstance(obj, type) or hasattr(obj, "__bases__")
opener = OpenerDirector()
default_classes = [ProxyHandler, UnknownHandler, HTTPHandler,
HTTPDefaultErrorHandler, HTTPRedirectHandler,
FTPHandler, FileHandler, HTTPErrorProcessor]
if hasattr(http.client, "HTTPSConnection"):
default_classes.append(HTTPSHandler)
skip = set()
for klass in default_classes:
for check in handlers:
if isclass(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 isclass(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):
if not hasattr(other, "handler_order"):
# Try to preserve the old behavior of having custom classes
# inserted after default ones (works only for custom user
# classes which are not aware of handler_order).
return True
return self.handler_order < other.handler_order
class HTTPErrorProcessor(BaseHandler):
"""Process HTTP error responses."""
handler_order = 1000 # after all other processing
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):
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):
raise HTTPError(req.full_url, code, msg, hdrs, fp)
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
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.
"""
m = req.get_method()
if (not (code in (301, 302, 303, 307) and m in ("GET", "HEAD")
or code in (301, 302, 303) and m == "POST")):
raise HTTPError(req.full_url, code, msg, headers, fp)
# Strictly (according to RFC 2616), 301 or 302 in response to
# a POST MUST NOT cause a redirection without confirmation
# from the user (of urllib.request, in this case). In practice,
# essentially all clients do redirect in this case, so we do
# the same.
# be conciliant with URIs containing a space
newurl = newurl.replace(' ', '%20')
CONTENT_HEADERS = ("content-length", "content-type")
newheaders = dict((k, v) for k, v in req.headers.items()
if k.lower() not in CONTENT_HEADERS)
return Request(newurl,
headers=newheaders,
origin_req_host=req.origin_req_host,
unverifiable=True)
# Implementation note: 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.
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["location"]
elif "uri" in headers:
newurl = headers["uri"]
else:
return
# fix a possible malformed URL
urlparts = urlparse(newurl)
# For security reasons we don't allow redirection to anything other
# than http, https or ftp.
if not urlparts.scheme in ('http', 'https', 'ftp'):
raise HTTPError(newurl, code,
msg +
" - Redirection to url '%s' is not allowed" %
newurl,
headers, fp)
if not urlparts.path:
urlparts = list(urlparts)
urlparts[2] = "/"
newurl = urlunparse(urlparts)
newurl = urljoin(req.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.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, timeout=req.timeout)
http_error_301 = http_error_303 = http_error_307 = 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):
if proxies is None:
proxies = getproxies()
assert hasattr(proxies, 'keys'), "proxies must be a mapping"
self.proxies = proxies
for type, url in proxies.items():
setattr(self, '%s_open' % type,
lambda r, proxy=url, type=type, meth=self.proxy_open: \
meth(r, proxy, type))
def proxy_open(self, req, proxy, type):
orig_type = req.type
proxy_type, user, password, hostport = _parse_proxy(proxy)
if proxy_type is None:
proxy_type = orig_type
if req.host and proxy_bypass(req.host):
return None
if user and password:
user_pass = '%s:%s' % (unquote(user),
unquote(password))
creds = base64.b64encode(user_pass.encode()).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, timeout=req.timeout)
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 isinstance(uri, str):
uri = [uri]
if not realm 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 domains.items():
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
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
self.retried = 0
def reset_retry_count(self):
self.retried = 0
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 self.retried > 5:
# retry sending the username:password 5 times before failing.
raise HTTPError(req.get_full_url(), 401, "basic auth failed",
headers, None)
else:
self.retried += 1
if authreq:
scheme = authreq.split()[0]
if not scheme.lower() == 'basic':
raise ValueError("AbstractBasicAuthHandler does not"
" support the following scheme: '%s'" %
scheme)
else:
mo = AbstractBasicAuthHandler.rx.search(authreq)
if mo:
scheme, quote, realm = mo.groups()
if scheme.lower() == 'basic':
response = self.retry_http_basic_auth(host, req, realm)
if response and response.code != 401:
self.retried = 0
return response
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 = "Basic " + base64.b64encode(raw.encode()).decode("ascii")
if req.headers.get(self.auth_header, None) == auth:
return None
req.add_unredirected_header(self.auth_header, auth)
return self.parent.open(req, timeout=req.timeout)
else:
return None
class HTTPBasicAuthHandler(AbstractBasicAuthHandler, BaseHandler):
auth_header = 'Authorization'
def http_error_401(self, req, fp, code, msg, headers):
url = req.full_url
response = self.http_error_auth_reqed('www-authenticate',
url, req, headers)
self.reset_retry_count()
return response
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 urllib.request does not (and
# should not, RFC 3986 s. 3.2.1) support requests for URLs containing
# userinfo.
authority = req.host
response = self.http_error_auth_reqed('proxy-authenticate',
authority, req, headers)
self.reset_retry_count()
return response
def randombytes(n):
"""Return n random bytes."""
return os.urandom(n)
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.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)
elif not scheme.lower() == 'basic':
raise ValueError("AbstractDigestAuthHandler does not support"
" the following scheme: '%s'" % scheme)
def retry_http_digest_auth(self, req, auth):
token, challenge = auth.split(' ', 1)
chal = parse_keqv_list(filter(None, parse_http_list(challenge)))
auth = self.get_authorization(req, chal)
if auth:
auth_val = 'Digest %s' % auth
if req.headers.get(self.auth_header, None) == auth_val:
return None
req.add_unredirected_header(self.auth_header, auth_val)
resp = self.parent.open(req, timeout=req.timeout)
return resp
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.
s = "%s:%s:%s:" % (self.nonce_count, nonce, time.ctime())
b = s.encode("ascii") + randombytes(8)
dig = hashlib.sha1(b).hexdigest()
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.full_url)
if user is None:
return None
# XXX not implemented yet
if req.data is not None:
entdig = self.get_entity_digest(req.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.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.
raise URLError("qop '%s' is not supported." % qop)
# XXX should the partial digests be encoded too?
base = 'username="%s", realm="%s", nonce="%s", uri="%s", ' \
'response="%s"' % (user, realm, nonce, req.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):
# lambdas assume digest modules are imported at the top level
if algorithm == 'MD5':
H = lambda x: hashlib.md5(x.encode("ascii")).hexdigest()
elif algorithm == 'SHA':
H = lambda x: hashlib.sha1(x.encode("ascii")).hexdigest()
# XXX MD5-sess
KD = lambda s, d: H("%s:%s" % (s, d))
return H, KD
def get_entity_digest(self, data, chal):
# XXX not implemented yet
return None
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.full_url)[1]
retry = self.http_error_auth_reqed('www-authenticate',
host, req, headers)
self.reset_retry_count()
return retry
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.host
retry = self.http_error_auth_reqed('proxy-authenticate',
host, req, headers)
self.reset_retry_count()
return retry
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.host
if not host:
raise URLError('no host given')
if request.data is not None: # POST
data = request.data
if isinstance(data, str):
raise TypeError("POST data should be bytes"
" or an iterable of bytes. It cannot be str.")
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'):
try:
mv = memoryview(data)
except TypeError:
if isinstance(data, collections.Iterable):
raise ValueError("Content-Length should be specified "
"for iterable data of type %r %r" % (type(data),
data))
else:
request.add_unredirected_header(
'Content-length', '%d' % (len(mv) * mv.itemsize))
sel_host = host
if request.has_proxy():
scheme, sel = splittype(request.selector)
sel_host, sel_path = splithost(sel)
if not request.has_header('Host'):
request.add_unredirected_header('Host', sel_host)
for name, value in self.parent.addheaders:
name = name.capitalize()
if not request.has_header(name):
request.add_unredirected_header(name, value)
return request
def do_open(self, http_class, req, **http_conn_args):
"""Return an HTTPResponse object for the request, using http_class.
http_class must implement the HTTPConnection API from http.client.
"""
host = req.host
if not host:
raise URLError('no host given')
# will parse host:port
h = http_class(host, timeout=req.timeout, **http_conn_args)
headers = dict(req.unredirected_hdrs)
headers.update(dict((k, v) for k, v in req.headers.items()
if k not in headers))
# TODO(jhylton): Should this be redesigned to handle
# persistent connections?
# 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"
headers = dict((name.title(), val) for name, val in headers.items())
if req._tunnel_host:
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]
h.set_tunnel(req._tunnel_host, headers=tunnel_headers)
try:
h.request(req.get_method(), req.selector, req.data, headers)
except socket.error as err: # timeout error
h.close()
raise URLError(err)
else:
r = h.getresponse()
r.url = req.get_full_url()
# This line replaces the .msg attribute of the HTTPResponse
# with .headers, because urllib clients expect the response to
# have the reason in .msg. It would be good to mark this
# attribute is deprecated and get then to use info() or
# .headers.
r.msg = r.reason
return r
class HTTPHandler(AbstractHTTPHandler):
def http_open(self, req):
return self.do_open(http.client.HTTPConnection, req)
http_request = AbstractHTTPHandler.do_request_
if hasattr(http.client, 'HTTPSConnection'):
import ssl
class HTTPSHandler(AbstractHTTPHandler):
def __init__(self, debuglevel=0, context=None, check_hostname=None):
AbstractHTTPHandler.__init__(self, debuglevel)
self._context = context
self._check_hostname = check_hostname
def https_open(self, req):
return self.do_open(http.client.HTTPSConnection, req,
context=self._context, check_hostname=self._check_hostname)
https_request = AbstractHTTPHandler.do_request_
class HTTPCookieProcessor(BaseHandler):
def __init__(self, cookiejar=None):
import http.cookiejar
if cookiejar is None:
cookiejar = http.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
https_request = http_request
https_response = http_response
class UnknownHandler(BaseHandler):
def unknown_open(self, req):
type = req.type
raise URLError('unknown url type: %s' % type)
def parse_keqv_list(l):
"""Parse list of key=value strings where keys are not duplicated."""
parsed = {}
for elt in l:
k, v = elt.split('=', 1)
if v[0] == '"' 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 [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.selector
if url[:2] == '//' and url[2:3] != '/' and (req.host and
req.host != 'localhost'):
if not req.host is self.get_names():
raise URLError("file:// scheme is supported only on localhost")
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 = tuple(
socket.gethostbyname_ex('localhost')[2] +
socket.gethostbyname_ex(socket.gethostname())[2])
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
import mimetypes
host = req.host
filename = req.selector
localfile = url2pathname(filename)
try:
stats = os.stat(localfile)
size = stats.st_size
modified = email.utils.formatdate(stats.st_mtime, usegmt=True)
mtype = mimetypes.guess_type(filename)[0]
headers = email.message_from_string(
'Content-type: %s\nContent-length: %d\nLast-modified: %s\n' %
(mtype or 'text/plain', size, modified))
if host:
host, port = splitport(host)
if not host or \
(not port and _safe_gethostbyname(host) in self.get_names()):
if host:
origurl = 'file://' + host + filename
else:
origurl = 'file://' + filename
return addinfourl(open(localfile, 'rb'), headers, origurl)
except OSError as msg:
# users shouldn't expect OSErrors coming from urlopen()
raise URLError(msg)
raise URLError('file not on local host')
def _safe_gethostbyname(host):
try:
return socket.gethostbyname(host)
except socket.gaierror:
return None
class FTPHandler(BaseHandler):
def ftp_open(self, req):
import ftplib
import mimetypes
host = req.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 = user or ''
passwd = passwd or ''
try:
host = socket.gethostbyname(host)
except socket.error as msg:
raise URLError(msg)
path, attrs = splitattr(req.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.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
headers = email.message_from_string(headers)
return addinfourl(fp, headers, req.full_url)
except ftplib.all_errors as msg:
exc = URLError('ftp error: %s' % msg)
raise exc.with_traceback(sys.exc_info()[2])
def connect_ftp(self, user, passwd, host, port, dirs, timeout):
return ftpwrapper(user, passwd, host, port, dirs, timeout,
persistent=False)
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 list(self.timeout.items()):
if v < t:
self.cache[k].close()
del self.cache[k]
del self.timeout[k]
self.soonest = min(list(self.timeout.values()))
# then check the size
if len(self.cache) == self.max_conns:
for k, v in list(self.timeout.items()):
if v == self.soonest:
del self.cache[k]
del self.timeout[k]
break
self.soonest = min(list(self.timeout.values()))
def clear_cache(self):
for conn in self.cache.values():
conn.close()
self.cache.clear()
self.timeout.clear()
# Code move from the old urllib module
MAXFTPCACHE = 10 # Trim the ftp cache beyond this size
# Helper for non-unix systems
if os.name == 'nt':
from nturl2path import url2pathname, pathname2url
else:
def url2pathname(pathname):
"""OS-specific conversion from a relative URL of the 'file' scheme
to a file system path; not recommended for general use."""
return unquote(pathname)
def pathname2url(pathname):
"""OS-specific conversion from a file system path to a relative URL
of the 'file' scheme; not recommended for general use."""
return quote(pathname)
# This really consists of two pieces:
# (1) a class which handles opening of all sorts of URLs
# (plus assorted utilities etc.)
# (2) a set of functions for parsing URLs
# XXX Should these be separated out into different modules?
ftpcache = {}
class URLopener:
"""Class to open URLs.
This is a class rather than just a subroutine because we may need
more than one set of global protocol-specific options.
Note -- this is a base class for those who don't want the
automatic handling of errors type 302 (relocated) and 401
(authorization needed)."""
__tempfiles = None
version = "Python-urllib/%s" % __version__
# Constructor
def __init__(self, proxies=None, **x509):
if proxies is None:
proxies = getproxies()
assert hasattr(proxies, 'keys'), "proxies must be a mapping"
self.proxies = proxies
self.key_file = x509.get('key_file')
self.cert_file = x509.get('cert_file')
self.addheaders = [('User-Agent', self.version)]
self.__tempfiles = []
self.__unlink = os.unlink # See cleanup()
self.tempcache = None
# Undocumented feature: if you assign {} to tempcache,
# it is used to cache files retrieved with
# self.retrieve(). This is not enabled by default
# since it does not work for changing documents (and I
# haven't got the logic to check expiration headers
# yet).
self.ftpcache = ftpcache
# Undocumented feature: you can use a different
# ftp cache by assigning to the .ftpcache member;
# in case you want logically independent URL openers
# XXX This is not threadsafe. Bah.
def __del__(self):
self.close()
def close(self):
self.cleanup()
def cleanup(self):
# This code sometimes runs when the rest of this module
# has already been deleted, so it can't use any globals
# or import anything.
if self.__tempfiles:
for file in self.__tempfiles:
try:
self.__unlink(file)
except OSError:
pass
del self.__tempfiles[:]
if self.tempcache:
self.tempcache.clear()
def addheader(self, *args):
"""Add a header to be used by the HTTP interface only
e.g. u.addheader('Accept', 'sound/basic')"""
self.addheaders.append(args)
# External interface
def open(self, fullurl, data=None):
"""Use URLopener().open(file) instead of open(file, 'r')."""
fullurl = unwrap(to_bytes(fullurl))
fullurl = quote(fullurl, safe="%/:=&?~#+!$,;'@()*[]|")
if self.tempcache and fullurl in self.tempcache:
filename, headers = self.tempcache[fullurl]
fp = open(filename, 'rb')
return addinfourl(fp, headers, fullurl)
urltype, url = splittype(fullurl)
if not urltype:
urltype = 'file'
if urltype in self.proxies:
proxy = self.proxies[urltype]
urltype, proxyhost = splittype(proxy)
host, selector = splithost(proxyhost)
url = (host, fullurl) # Signal special case to open_*()
else:
proxy = None
name = 'open_' + urltype
self.type = urltype
name = name.replace('-', '_')
if not hasattr(self, name):
if proxy:
return self.open_unknown_proxy(proxy, fullurl, data)
else:
return self.open_unknown(fullurl, data)
try:
if data is None:
return getattr(self, name)(url)
else:
return getattr(self, name)(url, data)
except socket.error as msg:
raise IOError('socket error', msg).with_traceback(sys.exc_info()[2])
def open_unknown(self, fullurl, data=None):
"""Overridable interface to open unknown URL type."""
type, url = splittype(fullurl)
raise IOError('url error', 'unknown url type', type)
def open_unknown_proxy(self, proxy, fullurl, data=None):
"""Overridable interface to open unknown URL type."""
type, url = splittype(fullurl)
raise IOError('url error', 'invalid proxy for %s' % type, proxy)
# External interface
def retrieve(self, url, filename=None, reporthook=None, data=None):
"""retrieve(url) returns (filename, headers) for a local object
or (tempfilename, headers) for a remote object."""
url = unwrap(to_bytes(url))
if self.tempcache and url in self.tempcache:
return self.tempcache[url]
type, url1 = splittype(url)
if filename is None and (not type or type == 'file'):
try:
fp = self.open_local_file(url1)
hdrs = fp.info()
fp.close()
return url2pathname(splithost(url1)[1]), hdrs
except IOError as msg:
pass
fp = self.open(url, data)
try:
headers = fp.info()
if filename:
tfp = open(filename, 'wb')
else:
import tempfile
garbage, path = splittype(url)
garbage, path = splithost(path or "")
path, garbage = splitquery(path or "")
path, garbage = splitattr(path or "")
suffix = os.path.splitext(path)[1]
(fd, filename) = tempfile.mkstemp(suffix)
self.__tempfiles.append(filename)
tfp = os.fdopen(fd, 'wb')
try:
result = filename, headers
if self.tempcache is not None:
self.tempcache[url] = result
bs = 1024*8
size = -1
read = 0
blocknum = 0
if reporthook:
if "content-length" in headers:
size = int(headers["Content-Length"])
reporthook(blocknum, bs, size)
while 1:
block = fp.read(bs)
if not block:
break
read += len(block)
tfp.write(block)
blocknum += 1
if reporthook:
reporthook(blocknum, bs, size)
finally:
tfp.close()
finally:
fp.close()
# raise exception if actual size does not match content-length header
if size >= 0 and read < size:
raise ContentTooShortError(
"retrieval incomplete: got only %i out of %i bytes"
% (read, size), result)
return result
# Each method named open_<type> knows how to open that type of URL
def _open_generic_http(self, connection_factory, url, data):
"""Make an HTTP connection using connection_class.
This is an internal method that should be called from
open_http() or open_https().
Arguments:
- connection_factory should take a host name and return an
HTTPConnection instance.
- url is the url to retrieval or a host, relative-path pair.
- data is payload for a POST request or None.
"""
user_passwd = None
proxy_passwd= None
if isinstance(url, str):
host, selector = splithost(url)
if host:
user_passwd, host = splituser(host)
host = unquote(host)
realhost = host
else:
host, selector = url
# check whether the proxy contains authorization information
proxy_passwd, host = splituser(host)
# now we proceed with the url we want to obtain
urltype, rest = splittype(selector)
url = rest
user_passwd = None
if urltype.lower() != 'http':
realhost = None
else:
realhost, rest = splithost(rest)
if realhost:
user_passwd, realhost = splituser(realhost)
if user_passwd:
selector = "%s://%s%s" % (urltype, realhost, rest)
if proxy_bypass(realhost):
host = realhost
#print "proxy via http:", host, selector
if not host: raise IOError('http error', 'no host given')
if proxy_passwd:
import base64
proxy_auth = base64.b64encode(proxy_passwd.encode()).decode('ascii')
else:
proxy_auth = None
if user_passwd:
import base64
auth = base64.b64encode(user_passwd.encode()).decode('ascii')
else:
auth = None
http_conn = connection_factory(host)
headers = {}
if proxy_auth:
headers["Proxy-Authorization"] = "Basic %s" % proxy_auth
if auth:
headers["Authorization"] = "Basic %s" % auth
if realhost:
headers["Host"] = realhost
# Add Connection:close as we don't support persistent connections yet.
# This helps in closing the socket and avoiding ResourceWarning
headers["Connection"] = "close"
for header, value in self.addheaders:
headers[header] = value
if data is not None:
headers["Content-Type"] = "application/x-www-form-urlencoded"
http_conn.request("POST", selector, data, headers)
else:
http_conn.request("GET", selector, headers=headers)
try:
response = http_conn.getresponse()
except http.client.BadStatusLine:
# something went wrong with the HTTP status line
raise URLError("http protocol error: bad status line")
# According to RFC 2616, "2xx" code indicates that the client's
# request was successfully received, understood, and accepted.
if 200 <= response.status < 300:
return addinfourl(response, response.msg, "http:" + url,
response.status)
else:
return self.http_error(
url, response.fp,
response.status, response.reason, response.msg, data)
def open_http(self, url, data=None):
"""Use HTTP protocol."""
return self._open_generic_http(http.client.HTTPConnection, url, data)
def http_error(self, url, fp, errcode, errmsg, headers, data=None):
"""Handle http errors.
Derived class can override this, or provide specific handlers
named http_error_DDD where DDD is the 3-digit error code."""
# First check if there's a specific handler for this error
name = 'http_error_%d' % errcode
if hasattr(self, name):
method = getattr(self, name)
if data is None:
result = method(url, fp, errcode, errmsg, headers)
else:
result = method(url, fp, errcode, errmsg, headers, data)
if result: return result
return self.http_error_default(url, fp, errcode, errmsg, headers)
def http_error_default(self, url, fp, errcode, errmsg, headers):
"""Default error handler: close the connection and raise IOError."""
void = fp.read()
fp.close()
raise HTTPError(url, errcode, errmsg, headers, None)
if _have_ssl:
def _https_connection(self, host):
return http.client.HTTPSConnection(host,
key_file=self.key_file,
cert_file=self.cert_file)
def open_https(self, url, data=None):
"""Use HTTPS protocol."""
return self._open_generic_http(self._https_connection, url, data)
def open_file(self, url):
"""Use local file or FTP depending on form of URL."""
if not isinstance(url, str):
raise URLError('file error', 'proxy support for file protocol currently not implemented')
if url[:2] == '//' and url[2:3] != '/' and url[2:12].lower() != 'localhost/':
raise ValueError("file:// scheme is supported only on localhost")
else:
return self.open_local_file(url)
def open_local_file(self, url):
"""Use local file."""
import mimetypes, email.utils
from io import StringIO
host, file = splithost(url)
localname = url2pathname(file)
try:
stats = os.stat(localname)
except OSError as e:
raise URLError(e.errno, e.strerror, e.filename)
size = stats.st_size
modified = email.utils.formatdate(stats.st_mtime, usegmt=True)
mtype = mimetypes.guess_type(url)[0]
headers = email.message_from_string(
'Content-Type: %s\nContent-Length: %d\nLast-modified: %s\n' %
(mtype or 'text/plain', size, modified))
if not host:
urlfile = file
if file[:1] == '/':
urlfile = 'file://' + file
return addinfourl(open(localname, 'rb'), headers, urlfile)
host, port = splitport(host)
if (not port
and socket.gethostbyname(host) in (localhost() + thishost())):
urlfile = file
if file[:1] == '/':
urlfile = 'file://' + file
return addinfourl(open(localname, 'rb'), headers, urlfile)
raise URLError('local file error', 'not on local host')
def open_ftp(self, url):
"""Use FTP protocol."""
if not isinstance(url, str):
raise URLError('ftp error', 'proxy support for ftp protocol currently not implemented')
import mimetypes
from io import StringIO
host, path = splithost(url)
if not host: raise URLError('ftp error', 'no host given')
host, port = splitport(host)
user, host = splituser(host)
if user: user, passwd = splitpasswd(user)
else: passwd = None
host = unquote(host)
user = unquote(user or '')
passwd = unquote(passwd or '')
host = socket.gethostbyname(host)
if not port:
import ftplib
port = ftplib.FTP_PORT
else:
port = int(port)
path, attrs = splitattr(path)
path = unquote(path)
dirs = path.split('/')
dirs, file = dirs[:-1], dirs[-1]
if dirs and not dirs[0]: dirs = dirs[1:]
if dirs and not dirs[0]: dirs[0] = '/'
key = user, host, port, '/'.join(dirs)
# XXX thread unsafe!
if len(self.ftpcache) > MAXFTPCACHE:
# Prune the cache, rather arbitrarily
for k in self.ftpcache.keys():
if k != key:
v = self.ftpcache[k]
del self.ftpcache[k]
v.close()
try:
if not key in self.ftpcache:
self.ftpcache[key] = \
ftpwrapper(user, passwd, host, port, dirs)
if not file: type = 'D'
else: type = 'I'
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) = self.ftpcache[key].retrfile(file, type)
mtype = mimetypes.guess_type("ftp:" + url)[0]
headers = ""
if mtype:
headers += "Content-Type: %s\n" % mtype
if retrlen is not None and retrlen >= 0:
headers += "Content-Length: %d\n" % retrlen
headers = email.message_from_string(headers)
return addinfourl(fp, headers, "ftp:" + url)
except ftperrors() as msg:
raise URLError('ftp error', msg).with_traceback(sys.exc_info()[2])
def open_data(self, url, data=None):
"""Use "data" URL."""
if not isinstance(url, str):
raise URLError('data error', 'proxy support for data protocol currently not implemented')
# ignore POSTed data
#
# syntax of data URLs:
# dataurl := "data:" [ mediatype ] [ ";base64" ] "," data
# mediatype := [ type "/" subtype ] *( ";" parameter )
# data := *urlchar
# parameter := attribute "=" value
try:
[type, data] = url.split(',', 1)
except ValueError:
raise IOError('data error', 'bad data URL')
if not type:
type = 'text/plain;charset=US-ASCII'
semi = type.rfind(';')
if semi >= 0 and '=' not in type[semi:]:
encoding = type[semi+1:]
type = type[:semi]
else:
encoding = ''
msg = []
msg.append('Date: %s'%time.strftime('%a, %d %b %Y %H:%M:%S GMT',
time.gmtime(time.time())))
msg.append('Content-type: %s' % type)
if encoding == 'base64':
import base64
# XXX is this encoding/decoding ok?
data = base64.decodebytes(data.encode('ascii')).decode('latin-1')
else:
data = unquote(data)
msg.append('Content-Length: %d' % len(data))
msg.append('')
msg.append(data)
msg = '\n'.join(msg)
headers = email.message_from_string(msg)
f = io.StringIO(msg)
#f.fileno = None # needed for addinfourl
return addinfourl(f, headers, url)
class FancyURLopener(URLopener):
"""Derived class with handlers for errors we can handle (perhaps)."""
def __init__(self, *args, **kwargs):
URLopener.__init__(self, *args, **kwargs)
self.auth_cache = {}
self.tries = 0
self.maxtries = 10
def http_error_default(self, url, fp, errcode, errmsg, headers):
"""Default error handling -- don't raise an exception."""
return addinfourl(fp, headers, "http:" + url, errcode)
def http_error_302(self, url, fp, errcode, errmsg, headers, data=None):
"""Error 302 -- relocated (temporarily)."""
self.tries += 1
if self.maxtries and self.tries >= self.maxtries:
if hasattr(self, "http_error_500"):
meth = self.http_error_500
else:
meth = self.http_error_default
self.tries = 0
return meth(url, fp, 500,
"Internal Server Error: Redirect Recursion", headers)
result = self.redirect_internal(url, fp, errcode, errmsg, headers,
data)
self.tries = 0
return result
def redirect_internal(self, url, fp, errcode, errmsg, headers, data):
if 'location' in headers:
newurl = headers['location']
elif 'uri' in headers:
newurl = headers['uri']
else:
return
void = fp.read()
fp.close()
# In case the server sent a relative URL, join with original:
newurl = urljoin(self.type + ":" + url, newurl)
urlparts = urlparse(newurl)
# For security reasons, we don't allow redirection to anything other
# than http, https and ftp.
# We are using newer HTTPError with older redirect_internal method
# This older method will get deprecated in 3.3
if not urlparts.scheme in ('http', 'https', 'ftp'):
raise HTTPError(newurl, errcode,
errmsg +
" Redirection to url '%s' is not allowed." % newurl,
headers, fp)
return self.open(newurl)
def http_error_301(self, url, fp, errcode, errmsg, headers, data=None):
"""Error 301 -- also relocated (permanently)."""
return self.http_error_302(url, fp, errcode, errmsg, headers, data)
def http_error_303(self, url, fp, errcode, errmsg, headers, data=None):
"""Error 303 -- also relocated (essentially identical to 302)."""
return self.http_error_302(url, fp, errcode, errmsg, headers, data)
def http_error_307(self, url, fp, errcode, errmsg, headers, data=None):
"""Error 307 -- relocated, but turn POST into error."""
if data is None:
return self.http_error_302(url, fp, errcode, errmsg, headers, data)
else:
return self.http_error_default(url, fp, errcode, errmsg, headers)
def http_error_401(self, url, fp, errcode, errmsg, headers, data=None,
retry=False):
"""Error 401 -- authentication required.
This function supports Basic authentication only."""
if not 'www-authenticate' in headers:
URLopener.http_error_default(self, url, fp,
errcode, errmsg, headers)
stuff = headers['www-authenticate']
import re
match = re.match('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff)
if not match:
URLopener.http_error_default(self, url, fp,
errcode, errmsg, headers)
scheme, realm = match.groups()
if scheme.lower() != 'basic':
URLopener.http_error_default(self, url, fp,
errcode, errmsg, headers)
if not retry:
URLopener.http_error_default(self, url, fp, errcode, errmsg,
headers)
name = 'retry_' + self.type + '_basic_auth'
if data is None:
return getattr(self,name)(url, realm)
else:
return getattr(self,name)(url, realm, data)
def http_error_407(self, url, fp, errcode, errmsg, headers, data=None,
retry=False):
"""Error 407 -- proxy authentication required.
This function supports Basic authentication only."""
if not 'proxy-authenticate' in headers:
URLopener.http_error_default(self, url, fp,
errcode, errmsg, headers)
stuff = headers['proxy-authenticate']
import re
match = re.match('[ \t]*([^ \t]+)[ \t]+realm="([^"]*)"', stuff)
if not match:
URLopener.http_error_default(self, url, fp,
errcode, errmsg, headers)
scheme, realm = match.groups()
if scheme.lower() != 'basic':
URLopener.http_error_default(self, url, fp,
errcode, errmsg, headers)
if not retry:
URLopener.http_error_default(self, url, fp, errcode, errmsg,
headers)
name = 'retry_proxy_' + self.type + '_basic_auth'
if data is None:
return getattr(self,name)(url, realm)
else:
return getattr(self,name)(url, realm, data)
def retry_proxy_http_basic_auth(self, url, realm, data=None):
host, selector = splithost(url)
newurl = 'http://' + host + selector
proxy = self.proxies['http']
urltype, proxyhost = splittype(proxy)
proxyhost, proxyselector = splithost(proxyhost)
i = proxyhost.find('@') + 1
proxyhost = proxyhost[i:]
user, passwd = self.get_user_passwd(proxyhost, realm, i)
if not (user or passwd): return None
proxyhost = "%s:%s@%s" % (quote(user, safe=''),
quote(passwd, safe=''), proxyhost)
self.proxies['http'] = 'http://' + proxyhost + proxyselector
if data is None:
return self.open(newurl)
else:
return self.open(newurl, data)
def retry_proxy_https_basic_auth(self, url, realm, data=None):
host, selector = splithost(url)
newurl = 'https://' + host + selector
proxy = self.proxies['https']
urltype, proxyhost = splittype(proxy)
proxyhost, proxyselector = splithost(proxyhost)
i = proxyhost.find('@') + 1
proxyhost = proxyhost[i:]
user, passwd = self.get_user_passwd(proxyhost, realm, i)
if not (user or passwd): return None
proxyhost = "%s:%s@%s" % (quote(user, safe=''),
quote(passwd, safe=''), proxyhost)
self.proxies['https'] = 'https://' + proxyhost + proxyselector
if data is None:
return self.open(newurl)
else:
return self.open(newurl, data)
def retry_http_basic_auth(self, url, realm, data=None):
host, selector = splithost(url)
i = host.find('@') + 1
host = host[i:]
user, passwd = self.get_user_passwd(host, realm, i)
if not (user or passwd): return None
host = "%s:%s@%s" % (quote(user, safe=''),
quote(passwd, safe=''), host)
newurl = 'http://' + host + selector
if data is None:
return self.open(newurl)
else:
return self.open(newurl, data)
def retry_https_basic_auth(self, url, realm, data=None):
host, selector = splithost(url)
i = host.find('@') + 1
host = host[i:]
user, passwd = self.get_user_passwd(host, realm, i)
if not (user or passwd): return None
host = "%s:%s@%s" % (quote(user, safe=''),
quote(passwd, safe=''), host)
newurl = 'https://' + host + selector
if data is None:
return self.open(newurl)
else:
return self.open(newurl, data)
def get_user_passwd(self, host, realm, clear_cache=0):
key = realm + '@' + host.lower()
if key in self.auth_cache:
if clear_cache:
del self.auth_cache[key]
else:
return self.auth_cache[key]
user, passwd = self.prompt_user_passwd(host, realm)
if user or passwd: self.auth_cache[key] = (user, passwd)
return user, passwd
def prompt_user_passwd(self, host, realm):
"""Override this in a GUI environment!"""
import getpass
try:
user = input("Enter username for %s at %s: " % (realm, host))
passwd = getpass.getpass("Enter password for %s in %s at %s: " %
(user, realm, host))
return user, passwd
except KeyboardInterrupt:
print()
return None, None
# Utility functions
_localhost = None
def localhost():
"""Return the IP address of the magic hostname 'localhost'."""
global _localhost
if _localhost is None:
_localhost = socket.gethostbyname('localhost')
return _localhost
_thishost = None
def thishost():
"""Return the IP addresses of the current host."""
global _thishost
if _thishost is None:
_thishost = tuple(socket.gethostbyname_ex(socket.gethostname()[2]))
return _thishost
_ftperrors = None
def ftperrors():
"""Return the set of errors raised by the FTP class."""
global _ftperrors
if _ftperrors is None:
import ftplib
_ftperrors = ftplib.all_errors
return _ftperrors
_noheaders = None
def noheaders():
"""Return an empty email Message object."""
global _noheaders
if _noheaders is None:
_noheaders = email.message_from_string("")
return _noheaders
# Utility classes
class ftpwrapper:
"""Class used by open_ftp() for cache of open FTP connections."""
def __init__(self, user, passwd, host, port, dirs, timeout=None,
persistent=True):
self.user = user
self.passwd = passwd
self.host = host
self.port = port
self.dirs = dirs
self.timeout = timeout
self.refcount = 0
self.keepalive = persistent
self.init()
def init(self):
import ftplib
self.busy = 0
self.ftp = ftplib.FTP()
self.ftp.connect(self.host, self.port, self.timeout)
self.ftp.login(self.user, self.passwd)
for dir in self.dirs:
self.ftp.cwd(dir)
def retrfile(self, file, type):
import ftplib
self.endtransfer()
if type in ('d', 'D'): cmd = 'TYPE A'; isdir = 1
else: cmd = 'TYPE ' + type; isdir = 0
try:
self.ftp.voidcmd(cmd)
except ftplib.all_errors:
self.init()
self.ftp.voidcmd(cmd)
conn = None
if file and not isdir:
# Try to retrieve as a file
try:
cmd = 'RETR ' + file
conn, retrlen = self.ftp.ntransfercmd(cmd)
except ftplib.error_perm as reason:
if str(reason)[:3] != '550':
raise URLError('ftp error', reason).with_traceback(
sys.exc_info()[2])
if not conn:
# Set transfer mode to ASCII!
self.ftp.voidcmd('TYPE A')
# Try a directory listing. Verify that directory exists.
if file:
pwd = self.ftp.pwd()
try:
try:
self.ftp.cwd(file)
except ftplib.error_perm as reason:
raise URLError('ftp error', reason) from reason
finally:
self.ftp.cwd(pwd)
cmd = 'LIST ' + file
else:
cmd = 'LIST'
conn, retrlen = self.ftp.ntransfercmd(cmd)
self.busy = 1
ftpobj = addclosehook(conn.makefile('rb'), self.file_close)
self.refcount += 1
conn.close()
# Pass back both a suitably decorated object and a retrieval length
return (ftpobj, retrlen)
def endtransfer(self):
if not self.busy:
return
self.busy = 0
try:
self.ftp.voidresp()
except ftperrors():
pass
def close(self):
self.keepalive = False
if self.refcount <= 0:
self.real_close()
def file_close(self):
self.endtransfer()
self.refcount -= 1
if self.refcount <= 0 and not self.keepalive:
self.real_close()
def real_close(self):
self.endtransfer()
try:
self.ftp.close()
except ftperrors():
pass
# Proxy handling
def getproxies_environment():
"""Return a dictionary of scheme -> proxy server URL mappings.
Scan the environment for variables named <scheme>_proxy;
this seems to be the standard convention. If you need a
different way, you can pass a proxies dictionary to the
[Fancy]URLopener constructor.
"""
proxies = {}
for name, value in os.environ.items():
name = name.lower()
if value and name[-6:] == '_proxy':
proxies[name[:-6]] = value
return proxies
def proxy_bypass_environment(host):
"""Test if proxies should not be used for a particular host.
Checks the environment for a variable named no_proxy, which should
be a list of DNS suffixes separated by commas, or '*' for all hosts.
"""
no_proxy = os.environ.get('no_proxy', '') or os.environ.get('NO_PROXY', '')
# '*' is special case for always bypass
if no_proxy == '*':
return 1
# strip port off host
hostonly, port = splitport(host)
# check if the host ends with any of the DNS suffixes
no_proxy_list = [proxy.strip() for proxy in no_proxy.split(',')]
for name in no_proxy_list:
if name and (hostonly.endswith(name) or host.endswith(name)):
return 1
# otherwise, don't bypass
return 0
# This code tests an OSX specific data structure but is testable on all
# platforms
def _proxy_bypass_macosx_sysconf(host, proxy_settings):
"""
Return True iff this host shouldn't be accessed using a proxy
This function uses the MacOSX framework SystemConfiguration
to fetch the proxy information.
proxy_settings come from _scproxy._get_proxy_settings or get mocked ie:
{ 'exclude_simple': bool,
'exceptions': ['foo.bar', '*.bar.com', '127.0.0.1', '10.1', '10.0/16']
}
"""
import re
import socket
from fnmatch import fnmatch
hostonly, port = splitport(host)
def ip2num(ipAddr):
parts = ipAddr.split('.')
parts = list(map(int, parts))
if len(parts) != 4:
parts = (parts + [0, 0, 0, 0])[:4]
return (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8) | parts[3]
# Check for simple host names:
if '.' not in host:
if proxy_settings['exclude_simple']:
return True
hostIP = None
for value in proxy_settings.get('exceptions', ()):
# Items in the list are strings like these: *.local, 169.254/16
if not value: continue
m = re.match(r"(\d+(?:\.\d+)*)(/\d+)?", value)
if m is not None:
if hostIP is None:
try:
hostIP = socket.gethostbyname(hostonly)
hostIP = ip2num(hostIP)
except socket.error:
continue
base = ip2num(m.group(1))
mask = m.group(2)
if mask is None:
mask = 8 * (m.group(1).count('.') + 1)
else:
mask = int(mask[1:])
mask = 32 - mask
if (hostIP >> mask) == (base >> mask):
return True
elif fnmatch(host, value):
return True
return False
if sys.platform == 'darwin':
from _scproxy import _get_proxy_settings, _get_proxies
def proxy_bypass_macosx_sysconf(host):
proxy_settings = _get_proxy_settings()
return _proxy_bypass_macosx_sysconf(host, proxy_settings)
def getproxies_macosx_sysconf():
"""Return a dictionary of scheme -> proxy server URL mappings.
This function uses the MacOSX framework SystemConfiguration
to fetch the proxy information.
"""
return _get_proxies()
def proxy_bypass(host):
if getproxies_environment():
return proxy_bypass_environment(host)
else:
return proxy_bypass_macosx_sysconf(host)
def getproxies():
return getproxies_environment() or getproxies_macosx_sysconf()
elif os.name == 'nt':
def getproxies_registry():
"""Return a dictionary of scheme -> proxy server URL mappings.
Win32 uses the registry to store proxies.
"""
proxies = {}
try:
import winreg
except ImportError:
# Std module, so should be around - but you never know!
return proxies
try:
internetSettings = winreg.OpenKey(winreg.HKEY_CURRENT_USER,
r'Software\Microsoft\Windows\CurrentVersion\Internet Settings')
proxyEnable = winreg.QueryValueEx(internetSettings,
'ProxyEnable')[0]
if proxyEnable:
# Returned as Unicode but problems if not converted to ASCII
proxyServer = str(winreg.QueryValueEx(internetSettings,
'ProxyServer')[0])
if '=' in proxyServer:
# Per-protocol settings
for p in proxyServer.split(';'):
protocol, address = p.split('=', 1)
# See if address has a type:// prefix
import re
if not re.match('^([^/:]+)://', address):
address = '%s://%s' % (protocol, address)
proxies[protocol] = address
else:
# Use one setting for all protocols
if proxyServer[:5] == 'http:':
proxies['http'] = proxyServer
else:
proxies['http'] = 'http://%s' % proxyServer
proxies['https'] = 'https://%s' % proxyServer
proxies['ftp'] = 'ftp://%s' % proxyServer
internetSettings.Close()
except (WindowsError, ValueError, TypeError):
# Either registry key not found etc, or the value in an
# unexpected format.
# proxies already set up to be empty so nothing to do
pass
return proxies
def getproxies():
"""Return a dictionary of scheme -> proxy server URL mappings.
Returns settings gathered from the environment, if specified,
or the registry.
"""
return getproxies_environment() or getproxies_registry()
def proxy_bypass_registry(host):
try:
import winreg
import re
except ImportError:
# Std modules, so should be around - but you never know!
return 0
try:
internetSettings = winreg.OpenKey(winreg.HKEY_CURRENT_USER,
r'Software\Microsoft\Windows\CurrentVersion\Internet Settings')
proxyEnable = winreg.QueryValueEx(internetSettings,
'ProxyEnable')[0]
proxyOverride = str(winreg.QueryValueEx(internetSettings,
'ProxyOverride')[0])
# ^^^^ Returned as Unicode but problems if not converted to ASCII
except WindowsError:
return 0
if not proxyEnable or not proxyOverride:
return 0
# try to make a host list from name and IP address.
rawHost, port = splitport(host)
host = [rawHost]
try:
addr = socket.gethostbyname(rawHost)
if addr != rawHost:
host.append(addr)
except socket.error:
pass
try:
fqdn = socket.getfqdn(rawHost)
if fqdn != rawHost:
host.append(fqdn)
except socket.error:
pass
# make a check value list from the registry entry: replace the
# '<local>' string by the localhost entry and the corresponding
# canonical entry.
proxyOverride = proxyOverride.split(';')
# now check if we match one of the registry values.
for test in proxyOverride:
if test == '<local>':
if '.' not in rawHost:
return 1
test = test.replace(".", r"\.") # mask dots
test = test.replace("*", r".*") # change glob sequence
test = test.replace("?", r".") # change glob char
for val in host:
# print "%s <--> %s" %( test, val )
if re.match(test, val, re.I):
return 1
return 0
def proxy_bypass(host):
"""Return a dictionary of scheme -> proxy server URL mappings.
Returns settings gathered from the environment, if specified,
or the registry.
"""
if getproxies_environment():
return proxy_bypass_environment(host)
else:
return proxy_bypass_registry(host)
else:
# By default use environment variables
getproxies = getproxies_environment
proxy_bypass = proxy_bypass_environment
Reference in New Issue View Git Blame Copy Permalink