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__ = "0.7.7" 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 # A request will be tried 'RETRIES' times if it fails at the socket/connection level. RETRIES = 2 # 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])*?(?=\")|(?@,;:\\\"/[\]?={} \t]+(?!\"))\"? WWW_AUTH_STRICT = re.compile(r"^(?:\s*(?:,\s*)?([^\0-\x1f\x7f-\xff()<>@,;:\\\"/[\]?={} \t]+)\s*=\s*\"?((?<=\")(?:[^\0-\x08\x0A-\x1f\x7f-\xff\\\"]|\\[\0-\x7f])*?(?=\")|(?@,;:\\\"/[\]?={} \t]+(?!\"))\"?)(.*)$") WWW_AUTH_RELAXED = re.compile(r"^(?:\s*(?:,\s*)?([^ \t\r\n=]+)\s*=\s*\"?((?<=\")(?:[^\\\"]|\\.)*?(?=\")|(? 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)|(? 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) 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 def proxy_info_from_environment(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 = proxy_info_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 def proxy_info_from_url(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 ProxyInfo( proxy_type = proxy_type, proxy_host = host, proxy_port = port, proxy_user = username or None, proxy_pass = password or None, ) 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" if self.proxy_info and self.proxy_info.isgood(): use_proxy = True proxy_type, proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass = self.proxy_info.astuple() else: use_proxy = False if use_proxy and proxy_rdns: host = proxy_host port = proxy_port else: host = self.host port = self.port for res in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM): af, socktype, proto, canonname, sa = res try: if use_proxy: self.sock = socks.socksocket(af, socktype, proto) self.sock.setproxy(proxy_type, proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass) 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) if use_proxy: print "proxy: %s ************" % str((proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass)) self.sock.connect((self.host, self.port) + sa[2:]) except socket.error, msg: if self.debuglevel > 0: print "connect fail: (%s, %s)" % (self.host, self.port) if use_proxy: print "proxy: %s" % str((proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass)) 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" if self.proxy_info and self.proxy_info.isgood(): use_proxy = True proxy_type, proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass = self.proxy_info.astuple() else: use_proxy = False if use_proxy and proxy_rdns: host = proxy_host port = proxy_port else: host = self.host port = self.port address_info = socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM) for family, socktype, proto, canonname, sockaddr in address_info: try: if use_proxy: sock = socks.socksocket(family, socktype, proto) sock.setproxy(proxy_type, proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass) 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 use_proxy: print "proxy: %s" % str((proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass)) 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: (%s, %s)" % (self.host, self.port) if use_proxy: print "proxy: %s" % str((proxy_host, proxy_port, proxy_rdns, proxy_user, proxy_pass)) 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 def _new_fixed_fetch(validate_certificate): def fixed_fetch(url, payload=None, method="GET", headers={}, allow_truncated=False, follow_redirects=True, deadline=5): return fetch(url, payload=payload, method=method, headers=header, allow_truncated=allow_truncated, follow_redirects=follow_redirects, deadline=deadline, validate_certificate=validate_certificate) return fixed_fetch class AppEngineHttpConnection(httplib.HTTPConnection): """Use httplib on App Engine, but compensate for its weirdness. The parameters key_file, cert_file, proxy_info, ca_certs, and disable_ssl_certificate_validation are all dropped on the ground. """ 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.HTTPConnection.__init__(self, host, port=port, strict=strict, timeout=timeout) class AppEngineHttpsConnection(httplib.HTTPSConnection): """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, 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, timeout=timeout) self._fetch = _new_fixed_fetch( not disable_ssl_certificate_validation) # 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=proxy_info_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 proxy_nfo_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 # Keep Authorization: headers on a redirect. self.forward_authorization_headers = False def __getstate__(self): state_dict = copy.copy(self.__dict__) # In case request is augmented by some foreign object such as # credentials which handle auth if 'request' in state_dict: del state_dict['request'] if 'connections' in state_dict: del state_dict['connections'] return state_dict def __setstate__(self, state): self.__dict__.update(state) self.connections = {} 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(RETRIES): try: if hasattr(conn, 'sock') and 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 hasattr(conn, 'sock') and conn.sock is None: if i < RETRIES-1: conn.close() conn.connect() continue else: conn.close() raise if i < RETRIES-1: conn.close() conn.connect() continue try: response = conn.getresponse() except (socket.error, httplib.HTTPException): if i < RETRIES-1: conn.close() conn.connect() continue else: conn.close() raise else: content = "" if method == "HEAD": conn.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 'authorization' in headers and not self.forward_authorization_headers: del headers['authorization'] 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 scheme == 'https': 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, ValueError): 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.lower()] = value self.status = int(self['status']) else: for key, value in info.iteritems(): self[key.lower()] = value self.status = int(self.get('status', self.status)) self.reason = self.get('reason', self.reason) def __getattr__(self, name): if name == 'dict': return self else: raise AttributeError, name