# Copyright 2016 Google LLC. All Rights Reserved. # # 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. """Tool for performing authenticated RPCs against App Engine.""" import gzip import hashlib import io import logging import os import re import socket import sys import time import urllib from googlecloudsdk.core.util import encoding from googlecloudsdk.appengine._internal import six_subset # pylint:disable=g-import-not-at-top # pylint:disable=invalid-name # Inline these directly rather than placing in six_subset since importing # urllib into six_subset seems to mess with the overridden version of # urllib/httplib that the NaCl runtime sandbox inserts for SSL purposes. if six_subset.PY3: import http.cookiejar import urllib.error import urllib.request BaseHandler = urllib.request.BaseHandler HTTPError = urllib.error.HTTPError HTTPHandler = urllib.request.HTTPHandler HTTPDefaultErrorHandler = urllib.request.HTTPDefaultErrorHandler HTTPCookieProcessor = urllib.request.HTTPCookieProcessor HTTPSHandler = urllib.request.HTTPSHandler HTTPErrorProcessor = urllib.request.HTTPErrorProcessor MozillaCookieJar = http.cookiejar.MozillaCookieJar ProxyHandler = urllib.request.ProxyHandler LoadError = http.cookiejar.LoadError OpenerDirector = urllib.request.OpenerDirector Request = urllib.request.Request UnknownHandler = urllib.request.UnknownHandler addinfourl_fn = urllib.response.addinfourl urlencode_fn = urllib.parse.urlencode else: import cookielib import fancy_urllib import urllib2 BaseHandler = urllib2.BaseHandler HTTPError = urllib2.HTTPError HTTPHandler = urllib2.HTTPHandler HTTPSHandler = fancy_urllib.FancyHTTPSHandler HTTPDefaultErrorHandler = urllib2.HTTPDefaultErrorHandler HTTPCookieProcessor = urllib2.HTTPCookieProcessor HTTPErrorProcessor = urllib2.HTTPErrorProcessor ProxyHandler = fancy_urllib.FancyProxyHandler MozillaCookieJar = cookielib.MozillaCookieJar LoadError = cookielib.LoadError OpenerDirector = urllib2.OpenerDirector UnknownHandler = urllib2.UnknownHandler Request = fancy_urllib.FancyRequest addinfourl_fn = urllib2.addinfourl urlencode_fn = urllib.urlencode # Inlined from fancy_urllib try: import ssl # pylint:disable=unused-import _CAN_VALIDATE_CERTS = True except ImportError: _CAN_VALIDATE_CERTS = False def can_validate_certs(): """Return True if we have the SSL package and can validate certificates.""" return _CAN_VALIDATE_CERTS # pylint:disable=g-import-not-at-top # pylint:disable=invalid-name logger = logging.getLogger('googlecloudsdk.appengine.tools.appengine_rpc') def GetPlatformToken(os_module=os, sys_module=sys, platform=sys.platform): """Returns a 'User-agent' token for the host system platform. Args: os_module, sys_module, platform: Used for testing. Returns: String containing the platform token for the host system. """ if hasattr(sys_module, "getwindowsversion"): windows_version = sys_module.getwindowsversion() version_info = ".".join(str(i) for i in windows_version[:4]) return platform + "/" + version_info elif hasattr(os_module, "uname"): uname = os_module.uname() return "%s/%s" % (uname[0], uname[2]) else: return "unknown" def HttpRequestToString(req, include_data=True): """Converts a urllib2.Request to a string. Args: req: urllib2.Request Returns: Multi-line string representing the request. """ headers = "" for header in req.header_items(): headers += "%s: %s\n" % (header[0], header[1]) template = ("%(method)s %(selector)s %(type)s/1.1\n" "Host: %(host)s\n" "%(headers)s") if include_data: template = template + "\n%(data)s" req_selector = req.selector if hasattr(req, "selector") else req.get_selector if req_selector is None: req_selector = "" req_type = req.type if hasattr(req, "type") else req.get_type() if req_type is None: req_type = "" req_host = req.host if hasattr(req, "host") else req.get_host() if req_host is None: req_host = "" req_data = req.data if hasattr(req, "data") else req.get_data() if req_data is None: req_data = "" return template % { "method": req.get_method(), "selector": req_selector, "type": req_type.upper(), "host": req_host, "headers": headers, "data": req_data, } class ClientLoginError(HTTPError): """Raised to indicate there was an error authenticating with ClientLogin.""" def __init__(self, url, code, msg, headers, args): HTTPError.__init__(self, url, code, msg, headers, None) self.args = args self._reason = args.get("Error") self.info = args.get("Info") def read(self): return '%d %s: %s' % (self.code, self.msg, self.reason) # In Python 2.7, the HTTPError was changed to have a property for 'reason'. # So we can no longer just use an attribute and need to define this ourselves. @property def reason(self): return self._reason class AbstractRpcServer(object): """Provides a common interface for a simple RPC server.""" # This flag will dictate which documentation to point to for suggestions. RUNTIME = "python" def __init__(self, host, auth_function, user_agent, source, host_override=None, extra_headers=None, save_cookies=False, auth_tries=3, account_type=None, debug_data=True, secure=True, ignore_certs=False, rpc_tries=3, options=None): """Creates a new HttpRpcServer. Args: host: The host to send requests to. auth_function: A function that takes no arguments and returns an (email, password) tuple when called. Will be called if authentication is required. user_agent: The user-agent string to send to the server. Specify None to omit the user-agent header. source: The source to specify in authentication requests. host_override: The host header to send to the server (defaults to host). extra_headers: A dict of extra headers to append to every request. Values supplied here will override other default headers that are supplied. save_cookies: If True, save the authentication cookies to local disk. If False, use an in-memory cookiejar instead. Subclasses must implement this functionality. Defaults to False. auth_tries: The number of times to attempt auth_function before failing. account_type: One of GOOGLE, HOSTED_OR_GOOGLE, or None for automatic. debug_data: Whether debugging output should include data contents. secure: If the requests sent using Send should be sent over HTTPS. ignore_certs: If the certificate mismatches should be ignored. rpc_tries: The number of rpc retries upon http server error (i.e. Response code >= 500 and < 600) before failing. options: the command line options (ignored in this implementation). """ if secure: self.scheme = "https" else: self.scheme = "http" self.ignore_certs = ignore_certs self.host = host self.host_override = host_override self.auth_function = auth_function self.source = source self.authenticated = False self.auth_tries = auth_tries self.debug_data = debug_data self.rpc_tries = rpc_tries # TODO(user): Consider validating account_type? self.account_type = account_type self.extra_headers = {} if user_agent: self.extra_headers["User-Agent"] = user_agent if extra_headers: self.extra_headers.update(extra_headers) self.save_cookies = save_cookies # By default there are no cookies to use or save. self.cookie_jar = MozillaCookieJar() self.opener = self._GetOpener() if self.host_override: logger.debug("Server: %s; Host: %s", self.host, self.host_override) else: logger.debug("Server: %s", self.host) # If we're being run against localhost, set the dev_appserver cookie. if ((self.host_override and self.host_override == "localhost") or self.host == "localhost" or self.host.startswith("localhost:")): self._DevAppServerAuthenticate() def _GetOpener(self): """Returns an OpenerDirector for making HTTP requests. Returns: A urllib2.OpenerDirector object. """ raise NotImplementedError def _CreateRequest(self, url, data=None): """Creates a new urllib request.""" req = Request(url, data=data) if self.host_override: req.add_header("Host", self.host_override) for key, value in self.extra_headers.items(): req.add_header(key, value) return req def _GetAuthToken(self, email, password): """Uses ClientLogin to authenticate the user, returning an auth token. Args: email: The user's email address password: The user's password Raises: ClientLoginError: If there was an error authenticating with ClientLogin. HTTPError: If there was some other form of HTTP error. Returns: The authentication token returned by ClientLogin. """ account_type = self.account_type if not account_type: # self.host is really hostport. if (self.host.split(':')[0].endswith(".google.com") or (self.host_override and self.host_override.split(':')[0].endswith(".google.com"))): # Needed for use inside Google. account_type = "HOSTED_OR_GOOGLE" else: account_type = "GOOGLE" data = { "Email": email, "Passwd": password, "service": "ah", "source": self.source, "accountType": account_type } req = self._CreateRequest( url=("https://%s/accounts/ClientLogin" % encoding.GetEncodedValue(os.environ, "APPENGINE_AUTH_SERVER", "www.google.com")), data=urlencode_fn(data)) try: response = self.opener.open(req) response_body = response.read() response_dict = dict(x.split("=") for x in response_body.split("\n") if x) if encoding.GetEncodedValue(os.environ, "APPENGINE_RPC_USE_SID", "0") == "1": self.extra_headers["Cookie"] = ( 'SID=%s; Path=/;' % response_dict["SID"]) return response_dict["Auth"] except HTTPError as e: if e.code == 403: body = e.read() response_dict = dict(x.split("=", 1) for x in body.split("\n") if x) raise ClientLoginError(req.get_full_url(), e.code, e.msg, e.headers, response_dict) else: raise def _GetAuthCookie(self, auth_token): """Fetches authentication cookies for an authentication token. Args: auth_token: The authentication token returned by ClientLogin. Raises: HTTPError: If there was an error fetching the authentication cookies. """ # This is an indicator to allow us to identify when we're successful. continue_location = "http://localhost/" args = {"continue": continue_location, "auth": auth_token} login_path = os.environ.get("APPCFG_LOGIN_PATH", "/_ah") req = self._CreateRequest("%s://%s%s/login?%s" % (self.scheme, self.host, login_path, urlencode_fn(args))) try: response = self.opener.open(req) except HTTPError as e: response = e if (response.code != 302 or response.info()["location"] != continue_location): raise HTTPError(req.get_full_url(), response.code, response.msg, response.headers, response.fp) self.authenticated = True def _Authenticate(self): """Authenticates the user. The authentication process works as follows: 1) We get a username and password from the user 2) We use ClientLogin to obtain an AUTH token for the user (see http://code.google.com/apis/accounts/AuthForInstalledApps.html). 3) We pass the auth token to /_ah/login on the server to obtain an authentication cookie. If login was successful, it tries to redirect us to the URL we provided. If we attempt to access the upload API without first obtaining an authentication cookie, it returns a 401 response and directs us to authenticate ourselves with ClientLogin. """ for unused_i in range(self.auth_tries): credentials = self.auth_function() try: auth_token = self._GetAuthToken(credentials[0], credentials[1]) if encoding.GetEncodedValue(os.environ, "APPENGINE_RPC_USE_SID", "0") == "1": return except ClientLoginError as e: # TODO(user): some of these cases probably only pertain to the # obsolete username/password authentication. if e.reason == "CaptchaRequired": print >>sys.stderr, ( "Please go to\n" "https://www.google.com/accounts/DisplayUnlockCaptcha\n" "and verify you are a human. Then try again.") break if e.reason == "NotVerified": print >>sys.stderr, "Account not verified." break if e.reason == "TermsNotAgreed": print >>sys.stderr, "User has not agreed to TOS." break if e.reason == "AccountDeleted": print >>sys.stderr, "The user account has been deleted." break if e.reason == "AccountDisabled": print >>sys.stderr, "The user account has been disabled." break if e.reason == "ServiceDisabled": print >>sys.stderr, ("The user's access to the service has been " "disabled.") break if e.reason == "ServiceUnavailable": print >>sys.stderr, "The service is not available; try again later." break raise self._GetAuthCookie(auth_token) return # TODO(user): refactor to share with devappserver2/login.py. @staticmethod def _CreateDevAppServerCookieData(email, admin): """Creates cookie payload data. Args: email: The user's email address. admin: True if the user is an admin; False otherwise. Returns: String containing the cookie payload. """ if email: user_id_digest = hashlib.md5(email.lower()).digest() user_id = "1" + "".join( ["%02d" % x for x in six_subset.iterbytes(user_id_digest)])[:20] else: user_id = "" return "%s:%s:%s" % (email, bool(admin), user_id) def _DevAppServerAuthenticate(self): """Authenticates the user on the dev_appserver.""" credentials = self.auth_function() value = self._CreateDevAppServerCookieData(credentials[0], True) self.extra_headers["Cookie"] = ('dev_appserver_login="%s"; Path=/;' % value) def Send(self, request_path, payload="", content_type="application/octet-stream", timeout=None, **kwargs): """Sends an RPC and returns the response. Args: request_path: The path to send the request to, eg /api/appversion/create. payload: The body of the request, or None to send an empty request. content_type: The Content-Type header to use. timeout: timeout in seconds; default None i.e. no timeout. (Note: for large requests on OS X, the timeout doesn't work right.) kwargs: Any keyword arguments are converted into query string parameters. Returns: The response body, as a string. """ old_timeout = socket.getdefaulttimeout() socket.setdefaulttimeout(timeout) try: tries = 0 auth_tried = False while True: tries += 1 url = "%s://%s%s" % (self.scheme, self.host, request_path) if kwargs: # To make testing simpler, always sort the url params. # Unfortunately we have no ordering information from the caller. url += "?" + urlencode_fn(sorted(kwargs.items())) req = self._CreateRequest(url=url, data=payload) req.add_header("Content-Type", content_type) # This header is necessary to prevent XSRF attacks, since the browser # cannot include this header, that means the request had to come from # another agent like appcfg.py. req.add_header("X-appcfg-api-version", "1") try: logger.debug('Sending %s request:\n%s', self.scheme.upper(), HttpRequestToString(req, include_data=self.debug_data)) f = self.opener.open(req) response = f.read() f.close() return response except HTTPError as e: logger.debug("Got http error, this is try %d: %s", tries, e) # TODO(user): consider whether all of the e.code cases still apply # now that we no longer have username/password authentication. if tries > self.rpc_tries: raise elif e.code == 401: # Unauthorized user. if auth_tried: raise auth_tried = True self._Authenticate() elif e.code >= 500 and e.code < 600: # Server Error - try again. continue elif e.code == 302: # Server may also return a 302 redirect to indicate authentication # is required. if auth_tried: raise auth_tried = True loc = e.info()["location"] logger.debug("Got 302 redirect. Location: %s", loc) if loc.startswith("https://www.google.com/accounts/ServiceLogin"): self._Authenticate() elif re.match( r"https://www\.google\.com/a/[a-z0-9\.\-]+/ServiceLogin", loc): self.account_type = encoding.GetEncodedValue( os.environ, "APPENGINE_RPC_HOSTED_LOGIN_TYPE", "HOSTED") self._Authenticate() elif loc.startswith("http://%s/_ah/login" % (self.host,)): self._DevAppServerAuthenticate() else: raise else: raise finally: socket.setdefaulttimeout(old_timeout) class ContentEncodingHandler(BaseHandler): """Request and handle HTTP Content-Encoding.""" def http_request(self, request): # Tell Google that we <3 gzip. request.add_header("Accept-Encoding", "gzip") # Append ' gzip' to the User-Agent. We need this in order to convince # GFE that we really do accept gzip-encoded responses, because the rest # of our User-Agent string does not identify us as a "modern" # browser. For the gory details of how GFE decides when it is OK to send # gzip-encoded responses, see HTTPServerRequest::CanCompressFor, # currently defined here: # # # For additional background, read this: # for header in request.headers: if header.lower() == "user-agent": request.headers[header] += " gzip" return request https_request = http_request def http_response(self, req, resp): """Handle encodings in the order that they are encountered.""" encodings = [] headers = resp.headers encoding_header = None for header in headers: if header.lower() == "content-encoding": encoding_header = header for encoding in headers[header].split(","): encoding = encoding.strip() if encoding: encodings.append(encoding) break if not encodings: return resp # encoding_header can't be None here as the above return on an empty list # of encodings would have prevented this line from being reached. del headers[encoding_header] fp = resp while encodings and encodings[-1].lower() == "gzip": fp = io.BytesIO(fp.read()) fp = gzip.GzipFile(fileobj=fp, mode="r") encodings.pop() if encodings: # Some unhandled encodings remain, leave them for other handlers. # There may be further encodings that we can handle nested within the # unhandled encoding. # TODO(user): The only resolution is to support more encodings. headers[encoding_header] = ", ".join(encodings) logger.warning("Unrecognized Content-Encoding: %s", encodings[-1]) msg = resp.msg if sys.version_info >= (2, 6): resp = addinfourl_fn(fp, headers, resp.url, resp.code) else: response_code = resp.code resp = addinfourl_fn(fp, headers, resp.url) resp.code = response_code resp.msg = msg return resp https_response = http_response class HttpRpcServer(AbstractRpcServer): """Provides a simplified RPC-style interface for HTTP requests.""" DEFAULT_COOKIE_FILE_PATH = "~/.appcfg_cookies" def __init__(self, *args, **kwargs): self.certpath = os.path.normpath(os.path.join( os.path.dirname(__file__), '..', '..', '..', 'lib', 'cacerts', 'cacerts.txt')) self.cert_file_available = ((not kwargs.get("ignore_certs", False)) and os.path.exists(self.certpath)) super(HttpRpcServer, self).__init__(*args, **kwargs) def _CreateRequest(self, url, data=None): """Creates a new urllib request.""" req = super(HttpRpcServer, self)._CreateRequest(url, data) if self.cert_file_available and can_validate_certs(): req.set_ssl_info(ca_certs=self.certpath) return req def _CheckCookie(self): """Warn if cookie is not valid for at least one minute.""" min_expire = time.time() + 60 for cookie in self.cookie_jar: if cookie.domain == self.host and not cookie.is_expired(min_expire): break else: print >>sys.stderr, "\nError: Machine system clock is incorrect.\n" def _Authenticate(self): """Save the cookie jar after authentication.""" if self.cert_file_available and not can_validate_certs(): # TODO(user): This warning will not fire if the user is already logged # in; we may also also want to warn on existing connections. logger.warn("""ssl module not found. Without the ssl module, the identity of the remote host cannot be verified, and connections may NOT be secure. To fix this, please install the ssl module from http://pypi.python.org/pypi/ssl . To learn more, see https://developers.google.com/appengine/kb/general#rpcssl""") super(HttpRpcServer, self)._Authenticate() if self.cookie_jar.filename is not None and self.save_cookies: logger.debug("Saving authentication cookies to %s", self.cookie_jar.filename) self.cookie_jar.save() self._CheckCookie() def _GetOpener(self): """Returns an OpenerDirector that supports cookies and ignores redirects. Returns: A urllib2.OpenerDirector object. """ opener = OpenerDirector() opener.add_handler(ProxyHandler()) opener.add_handler(UnknownHandler()) opener.add_handler(HTTPHandler()) opener.add_handler(HTTPDefaultErrorHandler()) opener.add_handler(HTTPSHandler()) opener.add_handler(HTTPErrorProcessor()) opener.add_handler(ContentEncodingHandler()) if self.save_cookies: self.cookie_jar.filename = os.path.expanduser( HttpRpcServer.DEFAULT_COOKIE_FILE_PATH) if os.path.exists(self.cookie_jar.filename): try: self.cookie_jar.load() self.authenticated = True logger.debug("Loaded authentication cookies from %s", self.cookie_jar.filename) except (OSError, IOError, LoadError) as e: # Failed to load cookies. The target file path is bad. logger.debug("Could not load authentication cookies; %s: %s", e.__class__.__name__, e) self.cookie_jar.filename = None else: # Create an empty cookie file. This must be created with the file # permissions set upfront in order to be secure. try: fd = os.open(self.cookie_jar.filename, os.O_CREAT, 0o600) os.close(fd) except (OSError, IOError) as e: # Failed to create cookie file. Don't try to save cookies. logger.debug("Could not create authentication cookies file; %s: %s", e.__class__.__name__, e) self.cookie_jar.filename = None opener.add_handler(HTTPCookieProcessor(self.cookie_jar)) return opener