import logging import urlparse import inspect import json from decimal import Decimal from zope.interface import implements from twisted.web import server, resource from twisted.internet import defer from twisted.python.failure import Failure from twisted.internet.error import ConnectionDone, ConnectionLost from txjsonrpc import jsonrpclib from traceback import format_exc from lbrynet import conf from lbrynet.core.Error import InvalidAuthenticationToken from lbrynet.core import utils from lbrynet.undecorated import undecorated from lbrynet.lbrynet_daemon.auth.util import APIKey, get_auth_message from lbrynet.lbrynet_daemon.auth.client import LBRY_SECRET log = logging.getLogger(__name__) EMPTY_PARAMS = [{}] class JSONRPCError(object): # http://www.jsonrpc.org/specification#error_object CODE_PARSE_ERROR = -32700 # Invalid JSON. Error while parsing the JSON text. CODE_INVALID_REQUEST = -32600 # The JSON sent is not a valid Request object. CODE_METHOD_NOT_FOUND = -32601 # The method does not exist / is not available. CODE_INVALID_PARAMS = -32602 # Invalid method parameter(s). CODE_INTERNAL_ERROR = -32603 # Internal JSON-RPC error (I think this is like a 500?) CODE_APPLICATION_ERROR = -32500 # Generic error with our app?? CODE_AUTHENTICATION_ERROR = -32501 # Authentication failed MESSAGES = { CODE_PARSE_ERROR: "Parse Error. Data is not valid JSON.", CODE_INVALID_REQUEST: "JSON data is not a valid Request", CODE_METHOD_NOT_FOUND: "Method Not Found", CODE_INVALID_PARAMS: "Invalid Params", CODE_INTERNAL_ERROR: "Internal Error", CODE_AUTHENTICATION_ERROR: "Authentication Failed", } HTTP_CODES = { CODE_INVALID_REQUEST: 400, CODE_PARSE_ERROR: 400, CODE_INVALID_PARAMS: 400, CODE_METHOD_NOT_FOUND: 404, CODE_INTERNAL_ERROR: 500, CODE_APPLICATION_ERROR: 500, CODE_AUTHENTICATION_ERROR: 401, } def __init__(self, message, code=CODE_APPLICATION_ERROR, traceback=None, data=None): assert isinstance(code, (int, long)), "'code' must be an int" assert (data is None or isinstance(data, dict)), "'data' must be None or a dict" self.code = code if message is None: message = self.MESSAGES[code] if code in self.MESSAGES else "Error" self.message = message self.data = {} if data is None else data if traceback is not None: self.data['traceback'] = traceback.split("\n") def to_dict(self): ret = { 'code': self.code, 'message': self.message, } if len(self.data): ret['data'] = self.data return ret @classmethod def create_from_exception(cls, exception, code=CODE_APPLICATION_ERROR, traceback=None): return cls(exception.message, code=code, traceback=traceback) def default_decimal(obj): if isinstance(obj, Decimal): return float(obj) class UnknownAPIMethodError(Exception): pass class NotAllowedDuringStartupError(Exception): pass def trap(err, *to_trap): err.trap(*to_trap) def jsonrpc_dumps_pretty(obj, **kwargs): try: id_ = kwargs.pop("id") except KeyError: id_ = None if isinstance(obj, JSONRPCError): data = {"jsonrpc": "2.0", "error": obj.to_dict(), "id": id_} else: data = {"jsonrpc": "2.0", "result": obj, "id": id_} return json.dumps(data, cls=jsonrpclib.JSONRPCEncoder, sort_keys=True, indent=2, separators=(',', ': '), **kwargs) + "\n" class AuthorizedBase(object): def __init__(self): self.authorized_functions = [] self.callable_methods = {} for methodname in dir(self): if methodname.startswith("jsonrpc_"): method = getattr(self, methodname) self.callable_methods.update({methodname.split("jsonrpc_")[1]: method}) if hasattr(method, '_auth_required'): self.authorized_functions.append(methodname.split("jsonrpc_")[1]) @staticmethod def auth_required(f): f._auth_required = True return f class AuthJSONRPCServer(AuthorizedBase): """Authorized JSONRPC server used as the base class for the LBRY API API methods are named with a leading "jsonrpc_" Decorators: @AuthJSONRPCServer.auth_required: this requires that the client include a valid hmac authentication token in their request Attributes: allowed_during_startup (list): list of api methods that are callable before the server has finished startup sessions (dict): dictionary of active session_id: lbrynet.lbrynet_daemon.auth.util.APIKey values authorized_functions (list): list of api methods that require authentication callable_methods (dict): dictionary of api_callable_name: method values """ implements(resource.IResource) isLeaf = True def __init__(self, use_authentication=None): AuthorizedBase.__init__(self) self._use_authentication = ( use_authentication if use_authentication is not None else conf.settings['use_auth_http'] ) self.announced_startup = False self.allowed_during_startup = [] self.sessions = {} def setup(self): return NotImplementedError() def _set_headers(self, request, data, update_secret=False): if conf.settings['allowed_origin']: request.setHeader("Access-Control-Allow-Origin", conf.settings['allowed_origin']) request.setHeader("Content-Type", "application/json") request.setHeader("Accept", "application/json-rpc") request.setHeader("Content-Length", str(len(data))) if update_secret: session_id = request.getSession().uid request.setHeader(LBRY_SECRET, self.sessions.get(session_id).secret) @staticmethod def _render_message(request, message): request.write(message) request.finish() def _render_error(self, failure, request, id_): if isinstance(failure, JSONRPCError): error = failure elif isinstance(failure, Failure): # maybe failure is JSONRPCError wrapped in a twisted Failure error = failure.check(JSONRPCError) if error is None: # maybe its a twisted Failure with another type of error error = JSONRPCError(failure.getErrorMessage(), traceback=failure.getTraceback()) else: # last resort, just cast it as a string error = JSONRPCError(str(failure)) response_content = jsonrpc_dumps_pretty(error, id=id_) self._set_headers(request, response_content) try: request.setResponseCode(JSONRPCError.HTTP_CODES[error.code]) except KeyError: request.setResponseCode(JSONRPCError.HTTP_CODES[JSONRPCError.CODE_INTERNAL_ERROR]) self._render_message(request, response_content) @staticmethod def _handle_dropped_request(result, d, function_name): if not d.called: log.warning("Cancelling dropped api request %s", function_name) d.cancel() def render(self, request): try: return self._render(request) except BaseException as e: log.error(e) error = JSONRPCError.create_from_exception(e, traceback=format_exc()) self._render_error(error, request, None) return server.NOT_DONE_YET def _render(self, request): time_in = utils.now() # assert self._check_headers(request), InvalidHeaderError session = request.getSession() session_id = session.uid finished_deferred = request.notifyFinish() if self._use_authentication: # if this is a new session, send a new secret and set the expiration # otherwise, session.touch() if self._initialize_session(session_id): def expire_session(): self._unregister_user_session(session_id) session.startCheckingExpiration() session.notifyOnExpire(expire_session) message = "OK" request.setResponseCode(200) self._set_headers(request, message, True) self._render_message(request, message) return server.NOT_DONE_YET else: session.touch() request.content.seek(0, 0) content = request.content.read() try: parsed = jsonrpclib.loads(content) except ValueError: log.warning("Unable to decode request json") self._render_error(JSONRPCError(None, JSONRPCError.CODE_PARSE_ERROR), request, None) return server.NOT_DONE_YET id_ = None try: function_name = parsed.get('method') args = parsed.get('params', {}) id_ = parsed.get('id', None) token = parsed.pop('hmac', None) except AttributeError as err: log.warning(err) self._render_error( JSONRPCError(None, code=JSONRPCError.CODE_INVALID_REQUEST), request, id_ ) return server.NOT_DONE_YET reply_with_next_secret = False if self._use_authentication: if function_name in self.authorized_functions: try: self._verify_token(session_id, parsed, token) except InvalidAuthenticationToken as err: log.warning("API validation failed") self._render_error( JSONRPCError.create_from_exception( err.message, code=JSONRPCError.CODE_AUTHENTICATION_ERROR, traceback=format_exc() ), request, id_ ) return server.NOT_DONE_YET self._update_session_secret(session_id) reply_with_next_secret = True try: function = self._get_jsonrpc_method(function_name) except UnknownAPIMethodError as err: log.warning('Failed to get function %s: %s', function_name, err) self._render_error( JSONRPCError(None, JSONRPCError.CODE_METHOD_NOT_FOUND), request, id_ ) return server.NOT_DONE_YET except NotAllowedDuringStartupError as err: log.warning('Function not allowed during startup %s: %s', function_name, err) self._render_error( JSONRPCError("This method is unavailable until the daemon is fully started", code=JSONRPCError.CODE_INVALID_REQUEST), request, id_ ) return server.NOT_DONE_YET if args == EMPTY_PARAMS or args == []: args_dict = {} elif isinstance(args, dict): args_dict = args elif len(args) == 1 and isinstance(args[0], dict): # TODO: this is for backwards compatibility. Remove this once API and UI are updated # TODO: also delete EMPTY_PARAMS then args_dict = args[0] else: # d = defer.maybeDeferred(function, *args) # if we want to support positional args too raise ValueError('Args must be a dict') params_error, erroneous_params = self._check_params(function, args_dict) if params_error is not None: params_error_message = '{} for {} command: {}'.format( params_error, function_name, ', '.join(erroneous_params) ) log.warning(params_error_message) self._render_error( JSONRPCError(params_error_message, code=JSONRPCError.CODE_INVALID_PARAMS), request, id_ ) return server.NOT_DONE_YET d = defer.maybeDeferred(function, **args_dict) # finished_deferred will callback when the request is finished # and errback if something went wrong. If the errback is # called, cancel the deferred stack. This is to prevent # request.finish() from being called on a closed request. finished_deferred.addErrback(self._handle_dropped_request, d, function_name) d.addCallback(self._callback_render, request, id_, reply_with_next_secret) # TODO: don't trap RuntimeError, which is presently caught to # handle deferredLists that won't peacefully cancel, namely # get_lbry_files d.addErrback(trap, ConnectionDone, ConnectionLost, defer.CancelledError, RuntimeError) d.addErrback(log.fail(self._render_error, request, id_), 'Failed to process %s', function_name) d.addBoth(lambda _: log.debug("%s took %f", function_name, (utils.now() - time_in).total_seconds())) return server.NOT_DONE_YET @staticmethod def _check_params(function, args_dict): argspec = inspect.getargspec(undecorated(function)) num_optional_params = 0 if argspec.defaults is None else len(argspec.defaults) missing_required_params = [ required_param for required_param in argspec.args[1:-num_optional_params] if required_param not in args_dict ] if len(missing_required_params): return 'Missing required parameters', missing_required_params extraneous_params = [] if argspec.keywords is not None else [ extra_param for extra_param in args_dict if extra_param not in argspec.args[1:] ] if len(extraneous_params): return 'Extraneous parameters', extraneous_params return None, None def _register_user_session(self, session_id): """ Add or update a HMAC secret for a session @param session_id: @return: secret """ log.info("Register api session") token = APIKey.new(seed=session_id) self.sessions.update({session_id: token}) def _unregister_user_session(self, session_id): log.info("Unregister API session") del self.sessions[session_id] def _check_headers(self, request): return ( self._check_header_source(request, 'Origin') and self._check_header_source(request, 'Referer')) def _check_header_source(self, request, header): """Check if the source of the request is allowed based on the header value.""" source = request.getHeader(header) if not self._check_source_of_request(source): log.warning("Attempted api call from invalid %s: %s", header, source) return False return True def _check_source_of_request(self, source): if source is None: return True if conf.settings['api_host'] == '0.0.0.0': return True server, port = self.get_server_port(source) return self._check_server_port(server, port) def _check_server_port(self, server, port): api = (conf.settings['api_host'], conf.settings['api_port']) return (server, port) == api or self._is_from_allowed_origin(server, port) def _is_from_allowed_origin(self, server, port): allowed_origin = conf.settings['allowed_origin'] if not allowed_origin: return False if allowed_origin == '*': return True allowed_server, allowed_port = self.get_server_port(allowed_origin) return (allowed_server, allowed_port) == (server, port) return ( server == conf.settings['api_host'] and port == conf.settings['api_port']) def get_server_port(self, origin): parsed = urlparse.urlparse(origin) server_port = parsed.netloc.split(':') assert len(server_port) <= 2 if len(server_port) == 2: return server_port[0], int(server_port[1]) else: return server_port[0], 80 def _verify_method_is_callable(self, function_path): if function_path not in self.callable_methods: raise UnknownAPIMethodError(function_path) if not self.announced_startup: if function_path not in self.allowed_during_startup: raise NotAllowedDuringStartupError(function_path) def _get_jsonrpc_method(self, function_path): self._verify_method_is_callable(function_path) return self.callable_methods.get(function_path) def _initialize_session(self, session_id): if not self.sessions.get(session_id, False): self._register_user_session(session_id) return True return False def _verify_token(self, session_id, message, token): if token is None: raise InvalidAuthenticationToken('Authentication token not found') to_auth = get_auth_message(message) api_key = self.sessions.get(session_id) if not api_key.compare_hmac(to_auth, token): raise InvalidAuthenticationToken('Invalid authentication token') def _update_session_secret(self, session_id): self.sessions.update({session_id: APIKey.new(name=session_id)}) def _callback_render(self, result, request, id_, auth_required=False): try: encoded_message = jsonrpc_dumps_pretty(result, id=id_, default=default_decimal) request.setResponseCode(200) self._set_headers(request, encoded_message, auth_required) self._render_message(request, encoded_message) except Exception as err: log.exception("Failed to render API response: %s", result) self._render_error(err, request, id_) @staticmethod def _render_response(result): return defer.succeed(result)