import fnmatch import importlib from datetime import datetime from typing import Any, Callable, Dict, List, Optional, Union from urllib.parse import unquote from django.http import HttpRequest from django.utils.translation import gettext as _ from zerver.lib.actions import ( check_send_private_message, check_send_stream_message, check_send_stream_message_by_id, send_rate_limited_pm_notification_to_bot_owner, ) from zerver.lib.exceptions import ErrorCode, JsonableError, StreamDoesNotExistError from zerver.lib.request import REQ, RequestNotes, has_request_variables from zerver.lib.send_email import FromAddress from zerver.lib.timestamp import timestamp_to_datetime from zerver.lib.validator import check_list, check_string from zerver.models import UserProfile MISSING_EVENT_HEADER_MESSAGE = """\ Hi there! Your bot {bot_name} just sent an HTTP request to {request_path} that is missing the HTTP {header_name} header. Because this header is how {integration_name} indicates the event type, this usually indicates a configuration issue, where you either entered the URL for a different integration, or are running an older version of the third-party service that doesn't provide that header. Contact {support_email} if you need help debugging! """ INVALID_JSON_MESSAGE = """ Hi there! It looks like you tried to set up the Zulip {webhook_name} integration, but didn't correctly configure the webhook to send data in the JSON format that this integration expects! """ SETUP_MESSAGE_TEMPLATE = "{integration} webhook has been successfully configured" SETUP_MESSAGE_USER_PART = " by {user_name}" # Django prefixes all custom HTTP headers with `HTTP_` DJANGO_HTTP_PREFIX = "HTTP_" def get_setup_webhook_message(integration: str, user_name: Optional[str] = None) -> str: content = SETUP_MESSAGE_TEMPLATE.format(integration=integration) if user_name: content += SETUP_MESSAGE_USER_PART.format(user_name=user_name) content = f"{content}." return content def notify_bot_owner_about_invalid_json( user_profile: UserProfile, webhook_client_name: str ) -> None: send_rate_limited_pm_notification_to_bot_owner( user_profile, user_profile.realm, INVALID_JSON_MESSAGE.format(webhook_name=webhook_client_name).strip(), ) class MissingHTTPEventHeader(JsonableError): code = ErrorCode.MISSING_HTTP_EVENT_HEADER data_fields = ["header"] def __init__(self, header: str) -> None: self.header = header @staticmethod def msg_format() -> str: return _("Missing the HTTP event header '{header}'") @has_request_variables def check_send_webhook_message( request: HttpRequest, user_profile: UserProfile, topic: str, body: str, complete_event_type: Optional[str] = None, stream: Optional[str] = REQ(default=None), user_specified_topic: Optional[str] = REQ("topic", default=None), only_events: Optional[List[str]] = REQ(default=None, json_validator=check_list(check_string)), exclude_events: Optional[List[str]] = REQ( default=None, json_validator=check_list(check_string) ), unquote_url_parameters: bool = False, ) -> None: if complete_event_type is not None: # Here, we implement Zulip's generic support for filtering # events sent by the third-party service. # # If complete_event_type is passed to this function, we will check the event # type against user configured lists of only_events and exclude events. # If the event does not satisfy the configuration, the function will return # without sending any messages. # # We match items in only_events and exclude_events using Unix # shell-style wildcards. if ( only_events is not None and all(not fnmatch.fnmatch(complete_event_type, pattern) for pattern in only_events) ) or ( exclude_events is not None and any(fnmatch.fnmatch(complete_event_type, pattern) for pattern in exclude_events) ): return client = RequestNotes.get_notes(request).client assert client is not None if stream is None: assert user_profile.bot_owner is not None check_send_private_message(user_profile, client, user_profile.bot_owner, body) else: # Some third-party websites (such as Atlassian's Jira), tend to # double escape their URLs in a manner that escaped space characters # (%20) are never properly decoded. We work around that by making sure # that the URL parameters are decoded on our end. if stream is not None and unquote_url_parameters: stream = unquote(stream) if user_specified_topic is not None: topic = user_specified_topic if unquote_url_parameters: topic = unquote(topic) try: if stream.isdecimal(): check_send_stream_message_by_id(user_profile, client, int(stream), topic, body) else: check_send_stream_message(user_profile, client, stream, topic, body) except StreamDoesNotExistError: # A PM will be sent to the bot_owner by check_message, notifying # that the webhook bot just tried to send a message to a non-existent # stream, so we don't need to re-raise it since it clutters up # webhook-errors.log pass def standardize_headers(input_headers: Union[None, Dict[str, Any]]) -> Dict[str, str]: """This method can be used to standardize a dictionary of headers with the standard format that Django expects. For reference, refer to: https://docs.djangoproject.com/en/3.2/ref/request-response/#django.http.HttpRequest.headers NOTE: Historically, Django's headers were not case-insensitive. We're still capitalizing our headers to make it easier to compare/search later if required. """ canonical_headers = {} if not input_headers: return {} for raw_header in input_headers: polished_header = raw_header.upper().replace("-", "_") if polished_header not in ["CONTENT_TYPE", "CONTENT_LENGTH"]: if not polished_header.startswith("HTTP_"): polished_header = "HTTP_" + polished_header canonical_headers[polished_header] = str(input_headers[raw_header]) return canonical_headers def validate_extract_webhook_http_header( request: HttpRequest, header: str, integration_name: str, fatal: bool = True ) -> Optional[str]: assert request.user.is_authenticated extracted_header = request.META.get(DJANGO_HTTP_PREFIX + header) if extracted_header is None and fatal: message_body = MISSING_EVENT_HEADER_MESSAGE.format( bot_name=request.user.full_name, request_path=request.path, header_name=header, integration_name=integration_name, support_email=FromAddress.SUPPORT, ) send_rate_limited_pm_notification_to_bot_owner( request.user, request.user.realm, message_body ) raise MissingHTTPEventHeader(header) return extracted_header def get_fixture_http_headers(integration_name: str, fixture_name: str) -> Dict["str", "str"]: """For integrations that require custom HTTP headers for some (or all) of their test fixtures, this method will call a specially named function from the target integration module to determine what set of HTTP headers goes with the given test fixture. """ view_module_name = f"zerver.webhooks.{integration_name}.view" try: # TODO: We may want to migrate to a more explicit registration # strategy for this behavior rather than a try/except import. view_module = importlib.import_module(view_module_name) fixture_to_headers = getattr(view_module, "fixture_to_headers") except (ImportError, AttributeError): return {} return fixture_to_headers(fixture_name) def get_http_headers_from_filename(http_header_key: str) -> Callable[[str], Dict[str, str]]: """If an integration requires an event type kind of HTTP header which can be easily (statically) determined, then name the fixtures in the format of "header_value__other_details" or even "header_value" and the use this method in the headers.py file for the integration.""" def fixture_to_headers(filename: str) -> Dict[str, str]: if "__" in filename: event_type = filename.split("__")[0] else: event_type = filename return {http_header_key: event_type} return fixture_to_headers def unix_milliseconds_to_timestamp(milliseconds: Any, webhook: str) -> datetime: """If an integration requires time input in unix milliseconds, this helper checks to ensure correct type and will catch any errors related to type or value and raise a JsonableError. Returns a datetime representing the time.""" try: # timestamps are in milliseconds so divide by 1000 seconds = milliseconds / 1000 return timestamp_to_datetime(seconds) except (ValueError, TypeError): raise JsonableError(_("The {} webhook expects time in milliseconds.").format(webhook))