mylar/lib/httplib2/__init__.py

1631 lines
66 KiB
Python
Raw Normal View History

from __future__ import generators
"""
httplib2
A caching http interface that supports ETags and gzip
to conserve bandwidth.
Requires Python 2.3 or later
Changelog:
2007-08-18, Rick: Modified so it's able to use a socks proxy if needed.
"""
__author__ = "Joe Gregorio (joe@bitworking.org)"
__copyright__ = "Copyright 2006, Joe Gregorio"
__contributors__ = ["Thomas Broyer (t.broyer@ltgt.net)",
"James Antill",
"Xavier Verges Farrero",
"Jonathan Feinberg",
"Blair Zajac",
"Sam Ruby",
"Louis Nyffenegger"]
__license__ = "MIT"
__version__ = "0.7.3"
import re
import sys
import email
import email.Utils
import email.Message
import email.FeedParser
import StringIO
import gzip
import zlib
import httplib
import urlparse
import urllib
import base64
import os
import copy
import calendar
import time
import random
import errno
try:
from hashlib import sha1 as _sha, md5 as _md5
except ImportError:
# prior to Python 2.5, these were separate modules
import sha
import md5
_sha = sha.new
_md5 = md5.new
import hmac
from gettext import gettext as _
import socket
try:
from httplib2 import socks
except ImportError:
try:
import socks
except ImportError:
socks = None
# Build the appropriate socket wrapper for ssl
try:
import ssl # python 2.6
ssl_SSLError = ssl.SSLError
def _ssl_wrap_socket(sock, key_file, cert_file,
disable_validation, ca_certs):
if disable_validation:
cert_reqs = ssl.CERT_NONE
else:
cert_reqs = ssl.CERT_REQUIRED
# We should be specifying SSL version 3 or TLS v1, but the ssl module
# doesn't expose the necessary knobs. So we need to go with the default
# of SSLv23.
return ssl.wrap_socket(sock, keyfile=key_file, certfile=cert_file,
cert_reqs=cert_reqs, ca_certs=ca_certs)
except (AttributeError, ImportError):
ssl_SSLError = None
def _ssl_wrap_socket(sock, key_file, cert_file,
disable_validation, ca_certs):
if not disable_validation:
raise CertificateValidationUnsupported(
"SSL certificate validation is not supported without "
"the ssl module installed. To avoid this error, install "
"the ssl module, or explicity disable validation.")
ssl_sock = socket.ssl(sock, key_file, cert_file)
return httplib.FakeSocket(sock, ssl_sock)
if sys.version_info >= (2,3):
from iri2uri import iri2uri
else:
def iri2uri(uri):
return uri
def has_timeout(timeout): # python 2.6
if hasattr(socket, '_GLOBAL_DEFAULT_TIMEOUT'):
return (timeout is not None and timeout is not socket._GLOBAL_DEFAULT_TIMEOUT)
return (timeout is not None)
__all__ = ['Http', 'Response', 'ProxyInfo', 'HttpLib2Error',
'RedirectMissingLocation', 'RedirectLimit', 'FailedToDecompressContent',
'UnimplementedDigestAuthOptionError', 'UnimplementedHmacDigestAuthOptionError',
'debuglevel', 'ProxiesUnavailableError']
# The httplib debug level, set to a non-zero value to get debug output
debuglevel = 0
# Python 2.3 support
if sys.version_info < (2,4):
def sorted(seq):
seq.sort()
return seq
# Python 2.3 support
def HTTPResponse__getheaders(self):
"""Return list of (header, value) tuples."""
if self.msg is None:
raise httplib.ResponseNotReady()
return self.msg.items()
if not hasattr(httplib.HTTPResponse, 'getheaders'):
httplib.HTTPResponse.getheaders = HTTPResponse__getheaders
# All exceptions raised here derive from HttpLib2Error
class HttpLib2Error(Exception): pass
# Some exceptions can be caught and optionally
# be turned back into responses.
class HttpLib2ErrorWithResponse(HttpLib2Error):
def __init__(self, desc, response, content):
self.response = response
self.content = content
HttpLib2Error.__init__(self, desc)
class RedirectMissingLocation(HttpLib2ErrorWithResponse): pass
class RedirectLimit(HttpLib2ErrorWithResponse): pass
class FailedToDecompressContent(HttpLib2ErrorWithResponse): pass
class UnimplementedDigestAuthOptionError(HttpLib2ErrorWithResponse): pass
class UnimplementedHmacDigestAuthOptionError(HttpLib2ErrorWithResponse): pass
class MalformedHeader(HttpLib2Error): pass
class RelativeURIError(HttpLib2Error): pass
class ServerNotFoundError(HttpLib2Error): pass
class ProxiesUnavailableError(HttpLib2Error): pass
class CertificateValidationUnsupported(HttpLib2Error): pass
class SSLHandshakeError(HttpLib2Error): pass
class NotSupportedOnThisPlatform(HttpLib2Error): pass
class CertificateHostnameMismatch(SSLHandshakeError):
def __init__(self, desc, host, cert):
HttpLib2Error.__init__(self, desc)
self.host = host
self.cert = cert
# Open Items:
# -----------
# Proxy support
# Are we removing the cached content too soon on PUT (only delete on 200 Maybe?)
# Pluggable cache storage (supports storing the cache in
# flat files by default. We need a plug-in architecture
# that can support Berkeley DB and Squid)
# == Known Issues ==
# Does not handle a resource that uses conneg and Last-Modified but no ETag as a cache validator.
# Does not handle Cache-Control: max-stale
# Does not use Age: headers when calculating cache freshness.
# The number of redirections to follow before giving up.
# Note that only GET redirects are automatically followed.
# Will also honor 301 requests by saving that info and never
# requesting that URI again.
DEFAULT_MAX_REDIRECTS = 5
# Default CA certificates file bundled with httplib2.
CA_CERTS = os.path.join(
os.path.dirname(os.path.abspath(__file__ )), "cacerts.txt")
# Which headers are hop-by-hop headers by default
HOP_BY_HOP = ['connection', 'keep-alive', 'proxy-authenticate', 'proxy-authorization', 'te', 'trailers', 'transfer-encoding', 'upgrade']
def _get_end2end_headers(response):
hopbyhop = list(HOP_BY_HOP)
hopbyhop.extend([x.strip() for x in response.get('connection', '').split(',')])
return [header for header in response.keys() if header not in hopbyhop]
URI = re.compile(r"^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?")
def parse_uri(uri):
"""Parses a URI using the regex given in Appendix B of RFC 3986.
(scheme, authority, path, query, fragment) = parse_uri(uri)
"""
groups = URI.match(uri).groups()
return (groups[1], groups[3], groups[4], groups[6], groups[8])
def urlnorm(uri):
(scheme, authority, path, query, fragment) = parse_uri(uri)
if not scheme or not authority:
raise RelativeURIError("Only absolute URIs are allowed. uri = %s" % uri)
authority = authority.lower()
scheme = scheme.lower()
if not path:
path = "/"
# Could do syntax based normalization of the URI before
# computing the digest. See Section 6.2.2 of Std 66.
request_uri = query and "?".join([path, query]) or path
scheme = scheme.lower()
defrag_uri = scheme + "://" + authority + request_uri
return scheme, authority, request_uri, defrag_uri
# Cache filename construction (original borrowed from Venus http://intertwingly.net/code/venus/)
re_url_scheme = re.compile(r'^\w+://')
re_slash = re.compile(r'[?/:|]+')
def safename(filename):
"""Return a filename suitable for the cache.
Strips dangerous and common characters to create a filename we
can use to store the cache in.
"""
try:
if re_url_scheme.match(filename):
if isinstance(filename,str):
filename = filename.decode('utf-8')
filename = filename.encode('idna')
else:
filename = filename.encode('idna')
except UnicodeError:
pass
if isinstance(filename,unicode):
filename=filename.encode('utf-8')
filemd5 = _md5(filename).hexdigest()
filename = re_url_scheme.sub("", filename)
filename = re_slash.sub(",", filename)
# limit length of filename
if len(filename)>200:
filename=filename[:200]
return ",".join((filename, filemd5))
NORMALIZE_SPACE = re.compile(r'(?:\r\n)?[ \t]+')
def _normalize_headers(headers):
return dict([ (key.lower(), NORMALIZE_SPACE.sub(value, ' ').strip()) for (key, value) in headers.iteritems()])
def _parse_cache_control(headers):
retval = {}
if headers.has_key('cache-control'):
parts = headers['cache-control'].split(',')
parts_with_args = [tuple([x.strip().lower() for x in part.split("=", 1)]) for part in parts if -1 != part.find("=")]
parts_wo_args = [(name.strip().lower(), 1) for name in parts if -1 == name.find("=")]
retval = dict(parts_with_args + parts_wo_args)
return retval
# Whether to use a strict mode to parse WWW-Authenticate headers
# Might lead to bad results in case of ill-formed header value,
# so disabled by default, falling back to relaxed parsing.
# Set to true to turn on, usefull for testing servers.
USE_WWW_AUTH_STRICT_PARSING = 0
# In regex below:
# [^\0-\x1f\x7f-\xff()<>@,;:\\\"/[\]?={} \t]+ matches a "token" as defined by HTTP
# "(?:[^\0-\x08\x0A-\x1f\x7f-\xff\\\"]|\\[\0-\x7f])*?" matches a "quoted-string" as defined by HTTP, when LWS have already been replaced by a single space
# Actually, as an auth-param value can be either a token or a quoted-string, they are combined in a single pattern which matches both:
# \"?((?<=\")(?:[^\0-\x1f\x7f-\xff\\\"]|\\[\0-\x7f])*?(?=\")|(?<!\")[^\0-\x08\x0A-\x1f\x7f-\xff()<>@,;:\\\"/[\]?={} \t]+(?!\"))\"?
WWW_AUTH_STRICT = re.compile(r"^(?:\s*(?:,\s*)?([^\0-\x1f\x7f-\xff()<>@,;:\\\"/[\]?={} \t]+)\s*=\s*\"?((?<=\")(?:[^\0-\x08\x0A-\x1f\x7f-\xff\\\"]|\\[\0-\x7f])*?(?=\")|(?<!\")[^\0-\x1f\x7f-\xff()<>@,;:\\\"/[\]?={} \t]+(?!\"))\"?)(.*)$")
WWW_AUTH_RELAXED = re.compile(r"^(?:\s*(?:,\s*)?([^ \t\r\n=]+)\s*=\s*\"?((?<=\")(?:[^\\\"]|\\.)*?(?=\")|(?<!\")[^ \t\r\n,]+(?!\"))\"?)(.*)$")
UNQUOTE_PAIRS = re.compile(r'\\(.)')
def _parse_www_authenticate(headers, headername='www-authenticate'):
"""Returns a dictionary of dictionaries, one dict
per auth_scheme."""
retval = {}
if headers.has_key(headername):
try:
authenticate = headers[headername].strip()
www_auth = USE_WWW_AUTH_STRICT_PARSING and WWW_AUTH_STRICT or WWW_AUTH_RELAXED
while authenticate:
# Break off the scheme at the beginning of the line
if headername == 'authentication-info':
(auth_scheme, the_rest) = ('digest', authenticate)
else:
(auth_scheme, the_rest) = authenticate.split(" ", 1)
# Now loop over all the key value pairs that come after the scheme,
# being careful not to roll into the next scheme
match = www_auth.search(the_rest)
auth_params = {}
while match:
if match and len(match.groups()) == 3:
(key, value, the_rest) = match.groups()
auth_params[key.lower()] = UNQUOTE_PAIRS.sub(r'\1', value) # '\\'.join([x.replace('\\', '') for x in value.split('\\\\')])
match = www_auth.search(the_rest)
retval[auth_scheme.lower()] = auth_params
authenticate = the_rest.strip()
except ValueError:
raise MalformedHeader("WWW-Authenticate")
return retval
def _entry_disposition(response_headers, request_headers):
"""Determine freshness from the Date, Expires and Cache-Control headers.
We don't handle the following:
1. Cache-Control: max-stale
2. Age: headers are not used in the calculations.
Not that this algorithm is simpler than you might think
because we are operating as a private (non-shared) cache.
This lets us ignore 's-maxage'. We can also ignore
'proxy-invalidate' since we aren't a proxy.
We will never return a stale document as
fresh as a design decision, and thus the non-implementation
of 'max-stale'. This also lets us safely ignore 'must-revalidate'
since we operate as if every server has sent 'must-revalidate'.
Since we are private we get to ignore both 'public' and
'private' parameters. We also ignore 'no-transform' since
we don't do any transformations.
The 'no-store' parameter is handled at a higher level.
So the only Cache-Control parameters we look at are:
no-cache
only-if-cached
max-age
min-fresh
"""
retval = "STALE"
cc = _parse_cache_control(request_headers)
cc_response = _parse_cache_control(response_headers)
if request_headers.has_key('pragma') and request_headers['pragma'].lower().find('no-cache') != -1:
retval = "TRANSPARENT"
if 'cache-control' not in request_headers:
request_headers['cache-control'] = 'no-cache'
elif cc.has_key('no-cache'):
retval = "TRANSPARENT"
elif cc_response.has_key('no-cache'):
retval = "STALE"
elif cc.has_key('only-if-cached'):
retval = "FRESH"
elif response_headers.has_key('date'):
date = calendar.timegm(email.Utils.parsedate_tz(response_headers['date']))
now = time.time()
current_age = max(0, now - date)
if cc_response.has_key('max-age'):
try:
freshness_lifetime = int(cc_response['max-age'])
except ValueError:
freshness_lifetime = 0
elif response_headers.has_key('expires'):
expires = email.Utils.parsedate_tz(response_headers['expires'])
if None == expires:
freshness_lifetime = 0
else:
freshness_lifetime = max(0, calendar.timegm(expires) - date)
else:
freshness_lifetime = 0
if cc.has_key('max-age'):
try:
freshness_lifetime = int(cc['max-age'])
except ValueError:
freshness_lifetime = 0
if cc.has_key('min-fresh'):
try:
min_fresh = int(cc['min-fresh'])
except ValueError:
min_fresh = 0
current_age += min_fresh
if freshness_lifetime > current_age:
retval = "FRESH"
return retval
def _decompressContent(response, new_content):
content = new_content
try:
encoding = response.get('content-encoding', None)
if encoding in ['gzip', 'deflate']:
if encoding == 'gzip':
content = gzip.GzipFile(fileobj=StringIO.StringIO(new_content)).read()
if encoding == 'deflate':
content = zlib.decompress(content)
response['content-length'] = str(len(content))
# Record the historical presence of the encoding in a way the won't interfere.
response['-content-encoding'] = response['content-encoding']
del response['content-encoding']
except IOError:
content = ""
raise FailedToDecompressContent(_("Content purported to be compressed with %s but failed to decompress.") % response.get('content-encoding'), response, content)
return content
def _updateCache(request_headers, response_headers, content, cache, cachekey):
if cachekey:
cc = _parse_cache_control(request_headers)
cc_response = _parse_cache_control(response_headers)
if cc.has_key('no-store') or cc_response.has_key('no-store'):
cache.delete(cachekey)
else:
info = email.Message.Message()
for key, value in response_headers.iteritems():
if key not in ['status','content-encoding','transfer-encoding']:
info[key] = value
# Add annotations to the cache to indicate what headers
# are variant for this request.
vary = response_headers.get('vary', None)
if vary:
vary_headers = vary.lower().replace(' ', '').split(',')
for header in vary_headers:
key = '-varied-%s' % header
try:
info[key] = request_headers[header]
except KeyError:
pass
status = response_headers.status
if status == 304:
status = 200
status_header = 'status: %d\r\n' % status
header_str = info.as_string()
header_str = re.sub("\r(?!\n)|(?<!\r)\n", "\r\n", header_str)
text = "".join([status_header, header_str, content])
cache.set(cachekey, text)
def _cnonce():
dig = _md5("%s:%s" % (time.ctime(), ["0123456789"[random.randrange(0, 9)] for i in range(20)])).hexdigest()
return dig[:16]
def _wsse_username_token(cnonce, iso_now, password):
return base64.b64encode(_sha("%s%s%s" % (cnonce, iso_now, password)).digest()).strip()
# For credentials we need two things, first
# a pool of credential to try (not necesarily tied to BAsic, Digest, etc.)
# Then we also need a list of URIs that have already demanded authentication
# That list is tricky since sub-URIs can take the same auth, or the
# auth scheme may change as you descend the tree.
# So we also need each Auth instance to be able to tell us
# how close to the 'top' it is.
class Authentication(object):
def __init__(self, credentials, host, request_uri, headers, response, content, http):
(scheme, authority, path, query, fragment) = parse_uri(request_uri)
self.path = path
self.host = host
self.credentials = credentials
self.http = http
def depth(self, request_uri):
(scheme, authority, path, query, fragment) = parse_uri(request_uri)
return request_uri[len(self.path):].count("/")
def inscope(self, host, request_uri):
# XXX Should we normalize the request_uri?
(scheme, authority, path, query, fragment) = parse_uri(request_uri)
return (host == self.host) and path.startswith(self.path)
def request(self, method, request_uri, headers, content):
"""Modify the request headers to add the appropriate
Authorization header. Over-rise this in sub-classes."""
pass
def response(self, response, content):
"""Gives us a chance to update with new nonces
or such returned from the last authorized response.
Over-rise this in sub-classes if necessary.
Return TRUE is the request is to be retried, for
example Digest may return stale=true.
"""
return False
class BasicAuthentication(Authentication):
def __init__(self, credentials, host, request_uri, headers, response, content, http):
Authentication.__init__(self, credentials, host, request_uri, headers, response, content, http)
def request(self, method, request_uri, headers, content):
"""Modify the request headers to add the appropriate
Authorization header."""
headers['authorization'] = 'Basic ' + base64.b64encode("%s:%s" % self.credentials).strip()
class DigestAuthentication(Authentication):
"""Only do qop='auth' and MD5, since that
is all Apache currently implements"""
def __init__(self, credentials, host, request_uri, headers, response, content, http):
Authentication.__init__(self, credentials, host, request_uri, headers, response, content, http)
challenge = _parse_www_authenticate(response, 'www-authenticate')
self.challenge = challenge['digest']
qop = self.challenge.get('qop', 'auth')
self.challenge['qop'] = ('auth' in [x.strip() for x in qop.split()]) and 'auth' or None
if self.challenge['qop'] is None:
raise UnimplementedDigestAuthOptionError( _("Unsupported value for qop: %s." % qop))
self.challenge['algorithm'] = self.challenge.get('algorithm', 'MD5').upper()
if self.challenge['algorithm'] != 'MD5':
raise UnimplementedDigestAuthOptionError( _("Unsupported value for algorithm: %s." % self.challenge['algorithm']))
self.A1 = "".join([self.credentials[0], ":", self.challenge['realm'], ":", self.credentials[1]])
self.challenge['nc'] = 1
def request(self, method, request_uri, headers, content, cnonce = None):
"""Modify the request headers"""
H = lambda x: _md5(x).hexdigest()
KD = lambda s, d: H("%s:%s" % (s, d))
A2 = "".join([method, ":", request_uri])
self.challenge['cnonce'] = cnonce or _cnonce()
request_digest = '"%s"' % KD(H(self.A1), "%s:%s:%s:%s:%s" % (self.challenge['nonce'],
'%08x' % self.challenge['nc'],
self.challenge['cnonce'],
self.challenge['qop'], H(A2)
))
headers['authorization'] = 'Digest username="%s", realm="%s", nonce="%s", uri="%s", algorithm=%s, response=%s, qop=%s, nc=%08x, cnonce="%s"' % (
self.credentials[0],
self.challenge['realm'],
self.challenge['nonce'],
request_uri,
self.challenge['algorithm'],
request_digest,
self.challenge['qop'],
self.challenge['nc'],
self.challenge['cnonce'],
)
if self.challenge.get('opaque'):
headers['authorization'] += ', opaque="%s"' % self.challenge['opaque']
self.challenge['nc'] += 1
def response(self, response, content):
if not response.has_key('authentication-info'):
challenge = _parse_www_authenticate(response, 'www-authenticate').get('digest', {})
if 'true' == challenge.get('stale'):
self.challenge['nonce'] = challenge['nonce']
self.challenge['nc'] = 1
return True
else:
updated_challenge = _parse_www_authenticate(response, 'authentication-info').get('digest', {})
if updated_challenge.has_key('nextnonce'):
self.challenge['nonce'] = updated_challenge['nextnonce']
self.challenge['nc'] = 1
return False
class HmacDigestAuthentication(Authentication):
"""Adapted from Robert Sayre's code and DigestAuthentication above."""
__author__ = "Thomas Broyer (t.broyer@ltgt.net)"
def __init__(self, credentials, host, request_uri, headers, response, content, http):
Authentication.__init__(self, credentials, host, request_uri, headers, response, content, http)
challenge = _parse_www_authenticate(response, 'www-authenticate')
self.challenge = challenge['hmacdigest']
# TODO: self.challenge['domain']
self.challenge['reason'] = self.challenge.get('reason', 'unauthorized')
if self.challenge['reason'] not in ['unauthorized', 'integrity']:
self.challenge['reason'] = 'unauthorized'
self.challenge['salt'] = self.challenge.get('salt', '')
if not self.challenge.get('snonce'):
raise UnimplementedHmacDigestAuthOptionError( _("The challenge doesn't contain a server nonce, or this one is empty."))
self.challenge['algorithm'] = self.challenge.get('algorithm', 'HMAC-SHA-1')
if self.challenge['algorithm'] not in ['HMAC-SHA-1', 'HMAC-MD5']:
raise UnimplementedHmacDigestAuthOptionError( _("Unsupported value for algorithm: %s." % self.challenge['algorithm']))
self.challenge['pw-algorithm'] = self.challenge.get('pw-algorithm', 'SHA-1')
if self.challenge['pw-algorithm'] not in ['SHA-1', 'MD5']:
raise UnimplementedHmacDigestAuthOptionError( _("Unsupported value for pw-algorithm: %s." % self.challenge['pw-algorithm']))
if self.challenge['algorithm'] == 'HMAC-MD5':
self.hashmod = _md5
else:
self.hashmod = _sha
if self.challenge['pw-algorithm'] == 'MD5':
self.pwhashmod = _md5
else:
self.pwhashmod = _sha
self.key = "".join([self.credentials[0], ":",
self.pwhashmod.new("".join([self.credentials[1], self.challenge['salt']])).hexdigest().lower(),
":", self.challenge['realm']
])
self.key = self.pwhashmod.new(self.key).hexdigest().lower()
def request(self, method, request_uri, headers, content):
"""Modify the request headers"""
keys = _get_end2end_headers(headers)
keylist = "".join(["%s " % k for k in keys])
headers_val = "".join([headers[k] for k in keys])
created = time.strftime('%Y-%m-%dT%H:%M:%SZ',time.gmtime())
cnonce = _cnonce()
request_digest = "%s:%s:%s:%s:%s" % (method, request_uri, cnonce, self.challenge['snonce'], headers_val)
request_digest = hmac.new(self.key, request_digest, self.hashmod).hexdigest().lower()
headers['authorization'] = 'HMACDigest username="%s", realm="%s", snonce="%s", cnonce="%s", uri="%s", created="%s", response="%s", headers="%s"' % (
self.credentials[0],
self.challenge['realm'],
self.challenge['snonce'],
cnonce,
request_uri,
created,
request_digest,
keylist,
)
def response(self, response, content):
challenge = _parse_www_authenticate(response, 'www-authenticate').get('hmacdigest', {})
if challenge.get('reason') in ['integrity', 'stale']:
return True
return False
class WsseAuthentication(Authentication):
"""This is thinly tested and should not be relied upon.
At this time there isn't any third party server to test against.
Blogger and TypePad implemented this algorithm at one point
but Blogger has since switched to Basic over HTTPS and
TypePad has implemented it wrong, by never issuing a 401
challenge but instead requiring your client to telepathically know that
their endpoint is expecting WSSE profile="UsernameToken"."""
def __init__(self, credentials, host, request_uri, headers, response, content, http):
Authentication.__init__(self, credentials, host, request_uri, headers, response, content, http)
def request(self, method, request_uri, headers, content):
"""Modify the request headers to add the appropriate
Authorization header."""
headers['authorization'] = 'WSSE profile="UsernameToken"'
iso_now = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
cnonce = _cnonce()
password_digest = _wsse_username_token(cnonce, iso_now, self.credentials[1])
headers['X-WSSE'] = 'UsernameToken Username="%s", PasswordDigest="%s", Nonce="%s", Created="%s"' % (
self.credentials[0],
password_digest,
cnonce,
iso_now)
class GoogleLoginAuthentication(Authentication):
def __init__(self, credentials, host, request_uri, headers, response, content, http):
from urllib import urlencode
Authentication.__init__(self, credentials, host, request_uri, headers, response, content, http)
challenge = _parse_www_authenticate(response, 'www-authenticate')
service = challenge['googlelogin'].get('service', 'xapi')
# Bloggger actually returns the service in the challenge
# For the rest we guess based on the URI
if service == 'xapi' and request_uri.find("calendar") > 0:
service = "cl"
# No point in guessing Base or Spreadsheet
#elif request_uri.find("spreadsheets") > 0:
# service = "wise"
auth = dict(Email=credentials[0], Passwd=credentials[1], service=service, source=headers['user-agent'])
resp, content = self.http.request("https://www.google.com/accounts/ClientLogin", method="POST", body=urlencode(auth), headers={'Content-Type': 'application/x-www-form-urlencoded'})
lines = content.split('\n')
d = dict([tuple(line.split("=", 1)) for line in lines if line])
if resp.status == 403:
self.Auth = ""
else:
self.Auth = d['Auth']
def request(self, method, request_uri, headers, content):
"""Modify the request headers to add the appropriate
Authorization header."""
headers['authorization'] = 'GoogleLogin Auth=' + self.Auth
AUTH_SCHEME_CLASSES = {
"basic": BasicAuthentication,
"wsse": WsseAuthentication,
"digest": DigestAuthentication,
"hmacdigest": HmacDigestAuthentication,
"googlelogin": GoogleLoginAuthentication
}
AUTH_SCHEME_ORDER = ["hmacdigest", "googlelogin", "digest", "wsse", "basic"]
class FileCache(object):
"""Uses a local directory as a store for cached files.
Not really safe to use if multiple threads or processes are going to
be running on the same cache.
"""
def __init__(self, cache, safe=safename): # use safe=lambda x: md5.new(x).hexdigest() for the old behavior
self.cache = cache
self.safe = safe
if not os.path.exists(cache):
os.makedirs(self.cache)
def get(self, key):
retval = None
cacheFullPath = os.path.join(self.cache, self.safe(key))
try:
f = file(cacheFullPath, "rb")
retval = f.read()
f.close()
except IOError:
pass
return retval
def set(self, key, value):
cacheFullPath = os.path.join(self.cache, self.safe(key))
f = file(cacheFullPath, "wb")
f.write(value)
f.close()
def delete(self, key):
cacheFullPath = os.path.join(self.cache, self.safe(key))
if os.path.exists(cacheFullPath):
os.remove(cacheFullPath)
class Credentials(object):
def __init__(self):
self.credentials = []
def add(self, name, password, domain=""):
self.credentials.append((domain.lower(), name, password))
def clear(self):
self.credentials = []
def iter(self, domain):
for (cdomain, name, password) in self.credentials:
if cdomain == "" or domain == cdomain:
yield (name, password)
class KeyCerts(Credentials):
"""Identical to Credentials except that
name/password are mapped to key/cert."""
pass
class AllHosts(object):
pass
class ProxyInfo(object):
"""Collect information required to use a proxy."""
bypass_hosts = ()
def __init__(self, proxy_type, proxy_host, proxy_port,
proxy_rdns=None, proxy_user=None, proxy_pass=None):
"""The parameter proxy_type must be set to one of socks.PROXY_TYPE_XXX
constants. For example:
p = ProxyInfo(proxy_type=socks.PROXY_TYPE_HTTP,
proxy_host='localhost', proxy_port=8000)
"""
self.proxy_type = proxy_type
self.proxy_host = proxy_host
self.proxy_port = proxy_port
self.proxy_rdns = proxy_rdns
self.proxy_user = proxy_user
self.proxy_pass = proxy_pass
def astuple(self):
return (self.proxy_type, self.proxy_host, self.proxy_port,
self.proxy_rdns, self.proxy_user, self.proxy_pass)
def isgood(self):
return (self.proxy_host != None) and (self.proxy_port != None)
@classmethod
def from_environment(cls, method='http'):
"""
Read proxy info from the environment variables.
"""
if method not in ['http', 'https']:
return
env_var = method + '_proxy'
url = os.environ.get(env_var, os.environ.get(env_var.upper()))
if not url:
return
pi = cls.from_url(url, method)
no_proxy = os.environ.get('no_proxy', os.environ.get('NO_PROXY', ''))
bypass_hosts = []
if no_proxy:
bypass_hosts = no_proxy.split(',')
# special case, no_proxy=* means all hosts bypassed
if no_proxy == '*':
bypass_hosts = AllHosts
pi.bypass_hosts = bypass_hosts
return pi
@classmethod
def from_url(cls, url, method='http'):
"""
Construct a ProxyInfo from a URL (such as http_proxy env var)
"""
url = urlparse.urlparse(url)
username = None
password = None
port = None
if '@' in url[1]:
ident, host_port = url[1].split('@', 1)
if ':' in ident:
username, password = ident.split(':', 1)
else:
password = ident
else:
host_port = url[1]
if ':' in host_port:
host, port = host_port.split(':', 1)
else:
host = host_port
if port:
port = int(port)
else:
port = dict(https=443, http=80)[method]
proxy_type = 3 # socks.PROXY_TYPE_HTTP
return cls(
proxy_type = proxy_type,
proxy_host = host,
proxy_port = port,
proxy_user = username or None,
proxy_pass = password or None,
)
def applies_to(self, hostname):
return not self.bypass_host(hostname)
def bypass_host(self, hostname):
"""Has this host been excluded from the proxy config"""
if self.bypass_hosts is AllHosts:
return True
bypass = False
for domain in self.bypass_hosts:
if hostname.endswith(domain):
bypass = True
return bypass
class HTTPConnectionWithTimeout(httplib.HTTPConnection):
"""
HTTPConnection subclass that supports timeouts
All timeouts are in seconds. If None is passed for timeout then
Python's default timeout for sockets will be used. See for example
the docs of socket.setdefaulttimeout():
http://docs.python.org/library/socket.html#socket.setdefaulttimeout
"""
def __init__(self, host, port=None, strict=None, timeout=None, proxy_info=None):
httplib.HTTPConnection.__init__(self, host, port, strict)
self.timeout = timeout
self.proxy_info = proxy_info
def connect(self):
"""Connect to the host and port specified in __init__."""
# Mostly verbatim from httplib.py.
if self.proxy_info and socks is None:
raise ProxiesUnavailableError(
'Proxy support missing but proxy use was requested!')
msg = "getaddrinfo returns an empty list"
for res in socket.getaddrinfo(self.host, self.port, 0,
socket.SOCK_STREAM):
af, socktype, proto, canonname, sa = res
try:
if self.proxy_info and self.proxy_info.isgood():
self.sock = socks.socksocket(af, socktype, proto)
self.sock.setproxy(*self.proxy_info.astuple())
else:
self.sock = socket.socket(af, socktype, proto)
self.sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
# Different from httplib: support timeouts.
if has_timeout(self.timeout):
self.sock.settimeout(self.timeout)
# End of difference from httplib.
if self.debuglevel > 0:
print "connect: (%s, %s)" % (self.host, self.port)
self.sock.connect((self.host, self.port) + sa[2:])
except socket.error, msg:
if self.debuglevel > 0:
print 'connect fail:', (self.host, self.port)
if self.sock:
self.sock.close()
self.sock = None
continue
break
if not self.sock:
raise socket.error, msg
class HTTPSConnectionWithTimeout(httplib.HTTPSConnection):
"""
This class allows communication via SSL.
All timeouts are in seconds. If None is passed for timeout then
Python's default timeout for sockets will be used. See for example
the docs of socket.setdefaulttimeout():
http://docs.python.org/library/socket.html#socket.setdefaulttimeout
"""
def __init__(self, host, port=None, key_file=None, cert_file=None,
strict=None, timeout=None, proxy_info=None,
ca_certs=None, disable_ssl_certificate_validation=False):
httplib.HTTPSConnection.__init__(self, host, port=port, key_file=key_file,
cert_file=cert_file, strict=strict)
self.timeout = timeout
self.proxy_info = proxy_info
if ca_certs is None:
ca_certs = CA_CERTS
self.ca_certs = ca_certs
self.disable_ssl_certificate_validation = \
disable_ssl_certificate_validation
# The following two methods were adapted from https_wrapper.py, released
# with the Google Appengine SDK at
# http://googleappengine.googlecode.com/svn-history/r136/trunk/python/google/appengine/tools/https_wrapper.py
# under the following license:
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
def _GetValidHostsForCert(self, cert):
"""Returns a list of valid host globs for an SSL certificate.
Args:
cert: A dictionary representing an SSL certificate.
Returns:
list: A list of valid host globs.
"""
if 'subjectAltName' in cert:
return [x[1] for x in cert['subjectAltName']
if x[0].lower() == 'dns']
else:
return [x[0][1] for x in cert['subject']
if x[0][0].lower() == 'commonname']
def _ValidateCertificateHostname(self, cert, hostname):
"""Validates that a given hostname is valid for an SSL certificate.
Args:
cert: A dictionary representing an SSL certificate.
hostname: The hostname to test.
Returns:
bool: Whether or not the hostname is valid for this certificate.
"""
hosts = self._GetValidHostsForCert(cert)
for host in hosts:
host_re = host.replace('.', '\.').replace('*', '[^.]*')
if re.search('^%s$' % (host_re,), hostname, re.I):
return True
return False
def connect(self):
"Connect to a host on a given (SSL) port."
msg = "getaddrinfo returns an empty list"
for family, socktype, proto, canonname, sockaddr in socket.getaddrinfo(
self.host, self.port, 0, socket.SOCK_STREAM):
try:
if self.proxy_info and self.proxy_info.isgood():
sock = socks.socksocket(family, socktype, proto)
sock.setproxy(*self.proxy_info.astuple())
else:
sock = socket.socket(family, socktype, proto)
sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
if has_timeout(self.timeout):
sock.settimeout(self.timeout)
sock.connect((self.host, self.port))
self.sock =_ssl_wrap_socket(
sock, self.key_file, self.cert_file,
self.disable_ssl_certificate_validation, self.ca_certs)
if self.debuglevel > 0:
print "connect: (%s, %s)" % (self.host, self.port)
if not self.disable_ssl_certificate_validation:
cert = self.sock.getpeercert()
hostname = self.host.split(':', 0)[0]
if not self._ValidateCertificateHostname(cert, hostname):
raise CertificateHostnameMismatch(
'Server presented certificate that does not match '
'host %s: %s' % (hostname, cert), hostname, cert)
except ssl_SSLError, e:
if sock:
sock.close()
if self.sock:
self.sock.close()
self.sock = None
# Unfortunately the ssl module doesn't seem to provide any way
# to get at more detailed error information, in particular
# whether the error is due to certificate validation or
# something else (such as SSL protocol mismatch).
if e.errno == ssl.SSL_ERROR_SSL:
raise SSLHandshakeError(e)
else:
raise
except (socket.timeout, socket.gaierror):
raise
except socket.error, msg:
if self.debuglevel > 0:
print 'connect fail:', (self.host, self.port)
if self.sock:
self.sock.close()
self.sock = None
continue
break
if not self.sock:
raise socket.error, msg
SCHEME_TO_CONNECTION = {
'http': HTTPConnectionWithTimeout,
'https': HTTPSConnectionWithTimeout
}
# Use a different connection object for Google App Engine
try:
from google.appengine.api import apiproxy_stub_map
if apiproxy_stub_map.apiproxy.GetStub('urlfetch') is None:
raise ImportError # Bail out; we're not actually running on App Engine.
from google.appengine.api.urlfetch import fetch
from google.appengine.api.urlfetch import InvalidURLError
from google.appengine.api.urlfetch import DownloadError
from google.appengine.api.urlfetch import ResponseTooLargeError
from google.appengine.api.urlfetch import SSLCertificateError
class ResponseDict(dict):
"""Is a dictionary that also has a read() method, so
that it can pass itself off as an httlib.HTTPResponse()."""
def read(self):
pass
class AppEngineHttpConnection(object):
"""Emulates an httplib.HTTPConnection object, but actually uses the Google
App Engine urlfetch library. This allows the timeout to be properly used on
Google App Engine, and avoids using httplib, which on Google App Engine is
just another wrapper around urlfetch.
"""
def __init__(self, host, port=None, key_file=None, cert_file=None,
strict=None, timeout=None, proxy_info=None, ca_certs=None,
disable_certificate_validation=False):
self.host = host
self.port = port
self.timeout = timeout
if key_file or cert_file or proxy_info or ca_certs:
raise NotSupportedOnThisPlatform()
self.response = None
self.scheme = 'http'
self.validate_certificate = not disable_certificate_validation
self.sock = True
def request(self, method, url, body, headers):
# Calculate the absolute URI, which fetch requires
netloc = self.host
if self.port:
netloc = '%s:%s' % (self.host, self.port)
absolute_uri = '%s://%s%s' % (self.scheme, netloc, url)
try:
response = fetch(absolute_uri, payload=body, method=method,
headers=headers, allow_truncated=False, follow_redirects=False,
deadline=self.timeout,
validate_certificate=self.validate_certificate)
self.response = ResponseDict(response.headers)
self.response['status'] = str(response.status_code)
self.response.status = response.status_code
setattr(self.response, 'read', lambda : response.content)
# Make sure the exceptions raised match the exceptions expected.
except InvalidURLError:
raise socket.gaierror('')
except (DownloadError, ResponseTooLargeError, SSLCertificateError):
raise httplib.HTTPException()
def getresponse(self):
if self.response:
return self.response
else:
raise httplib.HTTPException()
def set_debuglevel(self, level):
pass
def connect(self):
pass
def close(self):
pass
class AppEngineHttpsConnection(AppEngineHttpConnection):
"""Same as AppEngineHttpConnection, but for HTTPS URIs."""
def __init__(self, host, port=None, key_file=None, cert_file=None,
strict=None, timeout=None, proxy_info=None):
AppEngineHttpConnection.__init__(self, host, port, key_file, cert_file,
strict, timeout, proxy_info)
self.scheme = 'https'
# Update the connection classes to use the Googel App Engine specific ones.
SCHEME_TO_CONNECTION = {
'http': AppEngineHttpConnection,
'https': AppEngineHttpsConnection
}
except ImportError:
pass
class Http(object):
"""An HTTP client that handles:
- all methods
- caching
- ETags
- compression,
- HTTPS
- Basic
- Digest
- WSSE
and more.
"""
def __init__(self, cache=None, timeout=None,
proxy_info=ProxyInfo.from_environment,
ca_certs=None, disable_ssl_certificate_validation=False):
"""
If 'cache' is a string then it is used as a directory name for
a disk cache. Otherwise it must be an object that supports the
same interface as FileCache.
All timeouts are in seconds. If None is passed for timeout
then Python's default timeout for sockets will be used. See
for example the docs of socket.setdefaulttimeout():
http://docs.python.org/library/socket.html#socket.setdefaulttimeout
`proxy_info` may be:
- a callable that takes the http scheme ('http' or 'https') and
returns a ProxyInfo instance per request. By default, uses
ProxyInfo.from_environment.
- a ProxyInfo instance (static proxy config).
- None (proxy disabled).
ca_certs is the path of a file containing root CA certificates for SSL
server certificate validation. By default, a CA cert file bundled with
httplib2 is used.
If disable_ssl_certificate_validation is true, SSL cert validation will
not be performed.
"""
self.proxy_info = proxy_info
self.ca_certs = ca_certs
self.disable_ssl_certificate_validation = \
disable_ssl_certificate_validation
# Map domain name to an httplib connection
self.connections = {}
# The location of the cache, for now a directory
# where cached responses are held.
if cache and isinstance(cache, basestring):
self.cache = FileCache(cache)
else:
self.cache = cache
# Name/password
self.credentials = Credentials()
# Key/cert
self.certificates = KeyCerts()
# authorization objects
self.authorizations = []
# If set to False then no redirects are followed, even safe ones.
self.follow_redirects = True
# Which HTTP methods do we apply optimistic concurrency to, i.e.
# which methods get an "if-match:" etag header added to them.
self.optimistic_concurrency_methods = ["PUT", "PATCH"]
# If 'follow_redirects' is True, and this is set to True then
# all redirecs are followed, including unsafe ones.
self.follow_all_redirects = False
self.ignore_etag = False
self.force_exception_to_status_code = False
self.timeout = timeout
def _auth_from_challenge(self, host, request_uri, headers, response, content):
"""A generator that creates Authorization objects
that can be applied to requests.
"""
challenges = _parse_www_authenticate(response, 'www-authenticate')
for cred in self.credentials.iter(host):
for scheme in AUTH_SCHEME_ORDER:
if challenges.has_key(scheme):
yield AUTH_SCHEME_CLASSES[scheme](cred, host, request_uri, headers, response, content, self)
def add_credentials(self, name, password, domain=""):
"""Add a name and password that will be used
any time a request requires authentication."""
self.credentials.add(name, password, domain)
def add_certificate(self, key, cert, domain):
"""Add a key and cert that will be used
any time a request requires authentication."""
self.certificates.add(key, cert, domain)
def clear_credentials(self):
"""Remove all the names and passwords
that are used for authentication"""
self.credentials.clear()
self.authorizations = []
def _conn_request(self, conn, request_uri, method, body, headers):
for i in range(2):
try:
if conn.sock is None:
conn.connect()
conn.request(method, request_uri, body, headers)
except socket.timeout:
raise
except socket.gaierror:
conn.close()
raise ServerNotFoundError("Unable to find the server at %s" % conn.host)
except ssl_SSLError:
conn.close()
raise
except socket.error, e:
err = 0
if hasattr(e, 'args'):
err = getattr(e, 'args')[0]
else:
err = e.errno
if err == errno.ECONNREFUSED: # Connection refused
raise
except httplib.HTTPException:
# Just because the server closed the connection doesn't apparently mean
# that the server didn't send a response.
if conn.sock is None:
if i == 0:
conn.close()
conn.connect()
continue
else:
conn.close()
raise
if i == 0:
conn.close()
conn.connect()
continue
try:
response = conn.getresponse()
except (socket.error, httplib.HTTPException):
if i == 0:
conn.close()
conn.connect()
continue
else:
raise
else:
content = ""
if method == "HEAD":
response.close()
else:
content = response.read()
response = Response(response)
if method != "HEAD":
content = _decompressContent(response, content)
break
return (response, content)
def _request(self, conn, host, absolute_uri, request_uri, method, body, headers, redirections, cachekey):
"""Do the actual request using the connection object
and also follow one level of redirects if necessary"""
auths = [(auth.depth(request_uri), auth) for auth in self.authorizations if auth.inscope(host, request_uri)]
auth = auths and sorted(auths)[0][1] or None
if auth:
auth.request(method, request_uri, headers, body)
(response, content) = self._conn_request(conn, request_uri, method, body, headers)
if auth:
if auth.response(response, body):
auth.request(method, request_uri, headers, body)
(response, content) = self._conn_request(conn, request_uri, method, body, headers )
response._stale_digest = 1
if response.status == 401:
for authorization in self._auth_from_challenge(host, request_uri, headers, response, content):
authorization.request(method, request_uri, headers, body)
(response, content) = self._conn_request(conn, request_uri, method, body, headers, )
if response.status != 401:
self.authorizations.append(authorization)
authorization.response(response, body)
break
if (self.follow_all_redirects or (method in ["GET", "HEAD"]) or response.status == 303):
if self.follow_redirects and response.status in [300, 301, 302, 303, 307]:
# Pick out the location header and basically start from the beginning
# remembering first to strip the ETag header and decrement our 'depth'
if redirections:
if not response.has_key('location') and response.status != 300:
raise RedirectMissingLocation( _("Redirected but the response is missing a Location: header."), response, content)
# Fix-up relative redirects (which violate an RFC 2616 MUST)
if response.has_key('location'):
location = response['location']
(scheme, authority, path, query, fragment) = parse_uri(location)
if authority == None:
response['location'] = urlparse.urljoin(absolute_uri, location)
if response.status == 301 and method in ["GET", "HEAD"]:
response['-x-permanent-redirect-url'] = response['location']
if not response.has_key('content-location'):
response['content-location'] = absolute_uri
_updateCache(headers, response, content, self.cache, cachekey)
if headers.has_key('if-none-match'):
del headers['if-none-match']
if headers.has_key('if-modified-since'):
del headers['if-modified-since']
if response.has_key('location'):
location = response['location']
old_response = copy.deepcopy(response)
if not old_response.has_key('content-location'):
old_response['content-location'] = absolute_uri
redirect_method = method
if response.status in [302, 303]:
redirect_method = "GET"
body = None
(response, content) = self.request(location, redirect_method, body=body, headers = headers, redirections = redirections - 1)
response.previous = old_response
else:
raise RedirectLimit("Redirected more times than rediection_limit allows.", response, content)
elif response.status in [200, 203] and method in ["GET", "HEAD"]:
# Don't cache 206's since we aren't going to handle byte range requests
if not response.has_key('content-location'):
response['content-location'] = absolute_uri
_updateCache(headers, response, content, self.cache, cachekey)
return (response, content)
def _normalize_headers(self, headers):
return _normalize_headers(headers)
# Need to catch and rebrand some exceptions
# Then need to optionally turn all exceptions into status codes
# including all socket.* and httplib.* exceptions.
def request(self, uri, method="GET", body=None, headers=None, redirections=DEFAULT_MAX_REDIRECTS, connection_type=None):
""" Performs a single HTTP request.
The 'uri' is the URI of the HTTP resource and can begin
with either 'http' or 'https'. The value of 'uri' must be an absolute URI.
The 'method' is the HTTP method to perform, such as GET, POST, DELETE, etc.
There is no restriction on the methods allowed.
The 'body' is the entity body to be sent with the request. It is a string
object.
Any extra headers that are to be sent with the request should be provided in the
'headers' dictionary.
The maximum number of redirect to follow before raising an
exception is 'redirections. The default is 5.
The return value is a tuple of (response, content), the first
being and instance of the 'Response' class, the second being
a string that contains the response entity body.
"""
try:
if headers is None:
headers = {}
else:
headers = self._normalize_headers(headers)
if not headers.has_key('user-agent'):
headers['user-agent'] = "Python-httplib2/%s (gzip)" % __version__
uri = iri2uri(uri)
(scheme, authority, request_uri, defrag_uri) = urlnorm(uri)
domain_port = authority.split(":")[0:2]
if len(domain_port) == 2 and domain_port[1] == '443' and scheme == 'http':
scheme = 'https'
authority = domain_port[0]
proxy_info = self._get_proxy_info(scheme, authority)
conn_key = scheme+":"+authority
if conn_key in self.connections:
conn = self.connections[conn_key]
else:
if not connection_type:
connection_type = SCHEME_TO_CONNECTION[scheme]
certs = list(self.certificates.iter(authority))
if issubclass(connection_type, HTTPSConnectionWithTimeout):
if certs:
conn = self.connections[conn_key] = connection_type(
authority, key_file=certs[0][0],
cert_file=certs[0][1], timeout=self.timeout,
proxy_info=proxy_info,
ca_certs=self.ca_certs,
disable_ssl_certificate_validation=
self.disable_ssl_certificate_validation)
else:
conn = self.connections[conn_key] = connection_type(
authority, timeout=self.timeout,
proxy_info=proxy_info,
ca_certs=self.ca_certs,
disable_ssl_certificate_validation=
self.disable_ssl_certificate_validation)
else:
conn = self.connections[conn_key] = connection_type(
authority, timeout=self.timeout,
proxy_info=proxy_info)
conn.set_debuglevel(debuglevel)
if 'range' not in headers and 'accept-encoding' not in headers:
headers['accept-encoding'] = 'gzip, deflate'
info = email.Message.Message()
cached_value = None
if self.cache:
cachekey = defrag_uri
cached_value = self.cache.get(cachekey)
if cached_value:
# info = email.message_from_string(cached_value)
#
# Need to replace the line above with the kludge below
# to fix the non-existent bug not fixed in this
# bug report: http://mail.python.org/pipermail/python-bugs-list/2005-September/030289.html
try:
info, content = cached_value.split('\r\n\r\n', 1)
feedparser = email.FeedParser.FeedParser()
feedparser.feed(info)
info = feedparser.close()
feedparser._parse = None
except IndexError:
self.cache.delete(cachekey)
cachekey = None
cached_value = None
else:
cachekey = None
if method in self.optimistic_concurrency_methods and self.cache and info.has_key('etag') and not self.ignore_etag and 'if-match' not in headers:
# http://www.w3.org/1999/04/Editing/
headers['if-match'] = info['etag']
if method not in ["GET", "HEAD"] and self.cache and cachekey:
# RFC 2616 Section 13.10
self.cache.delete(cachekey)
# Check the vary header in the cache to see if this request
# matches what varies in the cache.
if method in ['GET', 'HEAD'] and 'vary' in info:
vary = info['vary']
vary_headers = vary.lower().replace(' ', '').split(',')
for header in vary_headers:
key = '-varied-%s' % header
value = info[key]
if headers.get(header, None) != value:
cached_value = None
break
if cached_value and method in ["GET", "HEAD"] and self.cache and 'range' not in headers:
if info.has_key('-x-permanent-redirect-url'):
# Should cached permanent redirects be counted in our redirection count? For now, yes.
if redirections <= 0:
raise RedirectLimit("Redirected more times than rediection_limit allows.", {}, "")
(response, new_content) = self.request(info['-x-permanent-redirect-url'], "GET", headers = headers, redirections = redirections - 1)
response.previous = Response(info)
response.previous.fromcache = True
else:
# Determine our course of action:
# Is the cached entry fresh or stale?
# Has the client requested a non-cached response?
#
# There seems to be three possible answers:
# 1. [FRESH] Return the cache entry w/o doing a GET
# 2. [STALE] Do the GET (but add in cache validators if available)
# 3. [TRANSPARENT] Do a GET w/o any cache validators (Cache-Control: no-cache) on the request
entry_disposition = _entry_disposition(info, headers)
if entry_disposition == "FRESH":
if not cached_value:
info['status'] = '504'
content = ""
response = Response(info)
if cached_value:
response.fromcache = True
return (response, content)
if entry_disposition == "STALE":
if info.has_key('etag') and not self.ignore_etag and not 'if-none-match' in headers:
headers['if-none-match'] = info['etag']
if info.has_key('last-modified') and not 'last-modified' in headers:
headers['if-modified-since'] = info['last-modified']
elif entry_disposition == "TRANSPARENT":
pass
(response, new_content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey)
if response.status == 304 and method == "GET":
# Rewrite the cache entry with the new end-to-end headers
# Take all headers that are in response
# and overwrite their values in info.
# unless they are hop-by-hop, or are listed in the connection header.
for key in _get_end2end_headers(response):
info[key] = response[key]
merged_response = Response(info)
if hasattr(response, "_stale_digest"):
merged_response._stale_digest = response._stale_digest
_updateCache(headers, merged_response, content, self.cache, cachekey)
response = merged_response
response.status = 200
response.fromcache = True
elif response.status == 200:
content = new_content
else:
self.cache.delete(cachekey)
content = new_content
else:
cc = _parse_cache_control(headers)
if cc.has_key('only-if-cached'):
info['status'] = '504'
response = Response(info)
content = ""
else:
(response, content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey)
except Exception, e:
if self.force_exception_to_status_code:
if isinstance(e, HttpLib2ErrorWithResponse):
response = e.response
content = e.content
response.status = 500
response.reason = str(e)
elif isinstance(e, socket.timeout):
content = "Request Timeout"
response = Response( {
"content-type": "text/plain",
"status": "408",
"content-length": len(content)
})
response.reason = "Request Timeout"
else:
content = str(e)
response = Response( {
"content-type": "text/plain",
"status": "400",
"content-length": len(content)
})
response.reason = "Bad Request"
else:
raise
return (response, content)
def _get_proxy_info(self, scheme, authority):
"""Return a ProxyInfo instance (or None) based on the scheme
and authority.
"""
hostname, port = urllib.splitport(authority)
proxy_info = self.proxy_info
if callable(proxy_info):
proxy_info = proxy_info(scheme)
if (hasattr(proxy_info, 'applies_to')
and not proxy_info.applies_to(hostname)):
proxy_info = None
return proxy_info
class Response(dict):
"""An object more like email.Message than httplib.HTTPResponse."""
"""Is this response from our local cache"""
fromcache = False
"""HTTP protocol version used by server. 10 for HTTP/1.0, 11 for HTTP/1.1. """
version = 11
"Status code returned by server. "
status = 200
"""Reason phrase returned by server."""
reason = "Ok"
previous = None
def __init__(self, info):
# info is either an email.Message or
# an httplib.HTTPResponse object.
if isinstance(info, httplib.HTTPResponse):
for key, value in info.getheaders():
self[key.lower()] = value
self.status = info.status
self['status'] = str(self.status)
self.reason = info.reason
self.version = info.version
elif isinstance(info, email.Message.Message):
for key, value in info.items():
self[key] = value
self.status = int(self['status'])
else:
for key, value in info.iteritems():
self[key] = value
self.status = int(self.get('status', self.status))
def __getattr__(self, name):
if name == 'dict':
return self
else:
raise AttributeError, name