"""A Python module for interacting with Slack's Web API.""" import copy import hashlib import hmac import io import json import logging import mimetypes import urllib import uuid import warnings from base64 import b64encode from ssl import SSLContext from typing import BinaryIO, Dict, List, Any from typing import Optional, Union from urllib.error import HTTPError from urllib.parse import urlencode from urllib.request import Request, urlopen, OpenerDirector, ProxyHandler, HTTPSHandler from slack_sdk.errors import SlackRequestError from .deprecation import show_deprecation_warning_if_any from .file_upload_v2_result import FileUploadV2Result from .internal_utils import ( convert_bool_to_0_or_1, get_user_agent, _get_url, _build_req_args, _build_unexpected_body_error_message, _upload_file_via_v2_url, ) from .slack_response import SlackResponse from slack_sdk.http_retry import default_retry_handlers from slack_sdk.http_retry.handler import RetryHandler from slack_sdk.http_retry.request import HttpRequest as RetryHttpRequest from slack_sdk.http_retry.response import HttpResponse as RetryHttpResponse from slack_sdk.http_retry.state import RetryState from slack_sdk.proxy_env_variable_loader import load_http_proxy_from_env class BaseClient: BASE_URL = "https://slack.com/api/" def __init__( self, token: Optional[str] = None, base_url: str = BASE_URL, timeout: int = 30, ssl: Optional[SSLContext] = None, proxy: Optional[str] = None, headers: Optional[dict] = None, user_agent_prefix: Optional[str] = None, user_agent_suffix: Optional[str] = None, # for Org-Wide App installation team_id: Optional[str] = None, logger: Optional[logging.Logger] = None, retry_handlers: Optional[List[RetryHandler]] = None, ): self.token = None if token is None else token.strip() """A string specifying an `xoxp-*` or `xoxb-*` token.""" if not base_url.endswith("/"): base_url += "/" self.base_url = base_url """A string representing the Slack API base URL. Default is `'https://slack.com/api/'`.""" self.timeout = timeout """The maximum number of seconds the client will wait to connect and receive a response from Slack. Default is 30 seconds.""" self.ssl = ssl """An [`ssl.SSLContext`](https://docs.python.org/3/library/ssl.html#ssl.SSLContext) instance, helpful for specifying your own custom certificate chain.""" self.proxy = proxy """String representing a fully-qualified URL to a proxy through which to route all requests to the Slack API. Even if this parameter is not specified, if any of the following environment variables are present, they will be loaded into this parameter: `HTTPS_PROXY`, `https_proxy`, `HTTP_PROXY` or `http_proxy`.""" self.headers = headers or {} """`dict` representing additional request headers to attach to all requests.""" self.headers["User-Agent"] = get_user_agent(user_agent_prefix, user_agent_suffix) self.default_params = {} if team_id is not None: self.default_params["team_id"] = team_id self._logger = logger if logger is not None else logging.getLogger(__name__) self.retry_handlers = retry_handlers if retry_handlers is not None else default_retry_handlers() if self.proxy is None or len(self.proxy.strip()) == 0: env_variable = load_http_proxy_from_env(self._logger) if env_variable is not None: self.proxy = env_variable # ------------------------- # accessors @property def logger(self) -> logging.Logger: """The logger this client uses.""" return self._logger # ------------------------- # api call def api_call( self, api_method: str, *, http_verb: str = "POST", files: Optional[dict] = None, data: Optional[dict] = None, params: Optional[dict] = None, json: Optional[dict] = None, headers: Optional[dict] = None, auth: Optional[dict] = None, ) -> SlackResponse: """Create a request and execute the API call to Slack. Args: api_method (str): The target Slack API method. e.g. 'chat.postMessage' http_verb (str): HTTP Verb. e.g. 'POST' files (dict): Files to multipart upload. e.g. {image OR file: file_object OR file_path} data: The body to attach to the request. If a dictionary is provided, form-encoding will take place. e.g. {'key1': 'value1', 'key2': 'value2'} params (dict): The URL parameters to append to the URL. e.g. {'key1': 'value1', 'key2': 'value2'} json (dict): JSON for the body to attach to the request (if files or data is not specified). e.g. {'key1': 'value1', 'key2': 'value2'} headers (dict): Additional request headers auth (dict): A dictionary that consists of client_id and client_secret Returns: (SlackResponse) The server's response to an HTTP request. Data from the response can be accessed like a dict. If the response included 'next_cursor' it can be iterated on to execute subsequent requests. Raises: SlackApiError: The following Slack API call failed: 'chat.postMessage'. SlackRequestError: Json data can only be submitted as POST requests. """ api_url = _get_url(self.base_url, api_method) headers = headers or {} headers.update(self.headers) req_args = _build_req_args( token=self.token, http_verb=http_verb, files=files, # type: ignore[arg-type] data=data, # type: ignore[arg-type] default_params=self.default_params, params=params, # type: ignore[arg-type] json=json, # type: ignore[arg-type] headers=headers, auth=auth, # type: ignore[arg-type] ssl=self.ssl, proxy=self.proxy, ) show_deprecation_warning_if_any(api_method) return self._sync_send(api_url=api_url, req_args=req_args) # ================================================================= # urllib based WebClient # ================================================================= def _sync_send(self, api_url, req_args) -> SlackResponse: params = req_args["params"] if "params" in req_args else None data = req_args["data"] if "data" in req_args else None files = req_args["files"] if "files" in req_args else None _json = req_args["json"] if "json" in req_args else None headers = req_args["headers"] if "headers" in req_args else None token = params.get("token") if params and "token" in params else None auth = req_args["auth"] if "auth" in req_args else None # Basic Auth for oauth.v2.access / oauth.access if auth is not None: headers = {} if isinstance(auth, str): headers["Authorization"] = auth elif isinstance(auth, dict): client_id, client_secret = auth["client_id"], auth["client_secret"] value = b64encode(f"{client_id}:{client_secret}".encode("utf-8")).decode("ascii") headers["Authorization"] = f"Basic {value}" else: self._logger.warning(f"As the auth: {auth}: {type(auth)} is unsupported, skipped") body_params = {} if params: body_params.update(params) if data: body_params.update(data) return self._urllib_api_call( token=token, url=api_url, query_params={}, body_params=body_params, files=files, # type: ignore[arg-type] json_body=_json, # type: ignore[arg-type] additional_headers=headers, # type: ignore[arg-type] ) def _request_for_pagination(self, api_url: str, req_args: Dict[str, Dict[str, Any]]) -> Dict[str, Any]: """This method is supposed to be used only for SlackResponse pagination You can paginate using Python's for iterator as below: for response in client.conversations_list(limit=100): # do something with each response here """ response = self._perform_urllib_http_request(url=api_url, args=req_args) return { "status_code": int(response["status"]), "headers": dict(response["headers"]), "data": json.loads(response["body"]), } def _urllib_api_call( self, *, token: Optional[str] = None, url: str, query_params: Dict[str, str], json_body: Dict, body_params: Dict[str, str], files: Dict[str, io.BytesIO], additional_headers: Dict[str, str], ) -> SlackResponse: """Performs a Slack API request and returns the result. Args: token: Slack API Token (either bot token or user token) url: Complete URL (e.g., https://slack.com/api/chat.postMessage) query_params: Query string json_body: JSON data structure (it's still a dict at this point), if you give this argument, body_params and files will be skipped body_params: Form body params files: Files to upload additional_headers: Request headers to append Returns: API response """ files_to_close: List[BinaryIO] = [] try: # True/False -> "1"/"0" query_params = convert_bool_to_0_or_1(query_params) # type: ignore[assignment] body_params = convert_bool_to_0_or_1(body_params) # type: ignore[assignment] if self._logger.level <= logging.DEBUG: def convert_params(values: dict) -> dict: if not values or not isinstance(values, dict): return {} return {k: ("(bytes)" if isinstance(v, bytes) else v) for k, v in values.items()} headers = {k: "(redacted)" if k.lower() == "authorization" else v for k, v in additional_headers.items()} self._logger.debug( f"Sending a request - url: {url}, " f"query_params: {convert_params(query_params)}, " f"body_params: {convert_params(body_params)}, " f"files: {convert_params(files)}, " f"json_body: {json_body}, " f"headers: {headers}" ) request_data = {} if files is not None and isinstance(files, dict) and len(files) > 0: if body_params: for k, v in body_params.items(): request_data.update({k: v}) for k, v in files.items(): # type: ignore[assignment] if isinstance(v, str): f: BinaryIO = open(v.encode("utf-8", "ignore"), "rb") files_to_close.append(f) request_data.update({k: f}) # type: ignore[dict-item] elif isinstance(v, (bytearray, bytes)): request_data.update({k: io.BytesIO(v)}) else: request_data.update({k: v}) request_headers = self._build_urllib_request_headers( token=token or self.token, # type: ignore[arg-type] has_json=json is not None, has_files=files is not None, additional_headers=additional_headers, ) request_args = { "headers": request_headers, "data": request_data, "params": body_params, "files": files, "json": json_body, } if query_params: q = urlencode(query_params) url = f"{url}&{q}" if "?" in url else f"{url}?{q}" response = self._perform_urllib_http_request(url=url, args=request_args) # type: ignore[arg-type] response_body = response.get("body", None) response_body_data: Optional[Union[dict, bytes]] = response_body if response_body is not None and not isinstance(response_body, bytes): try: response_body_data = json.loads(response["body"]) except json.decoder.JSONDecodeError: message = _build_unexpected_body_error_message(response.get("body", "")) self._logger.error(f"Failed to decode Slack API response: {message}") response_body_data = {"ok": False, "error": message} all_params: Dict[str, Any] = copy.copy(body_params) if body_params is not None else {} if query_params: all_params.update(query_params) request_args["params"] = all_params # for backward-compatibility return SlackResponse( client=self, http_verb="POST", # you can use POST method for all the Web APIs api_url=url, req_args=request_args, data=response_body_data, # type: ignore[arg-type] headers=dict(response["headers"]), status_code=response["status"], ).validate() finally: for f in files_to_close: if not f.closed: f.close() def _perform_urllib_http_request(self, *, url: str, args: Dict[str, Dict[str, Any]]) -> Dict[str, Any]: """Performs an HTTP request and parses the response. Args: url: Complete URL (e.g., https://slack.com/api/chat.postMessage) args: args has "headers", "data", "params", and "json" "headers": Dict[str, str] "data": Dict[str, Any] "params": Dict[str, str], "json": Dict[str, Any], Returns: dict {status: int, headers: Headers, body: str} """ headers = args["headers"] body: Optional[Union[bytes, str]] = None if args["json"]: body = json.dumps(args["json"]) headers["Content-Type"] = "application/json;charset=utf-8" elif args["data"]: boundary = f"--------------{uuid.uuid4()}" sep_boundary = b"\r\n--" + boundary.encode("ascii") end_boundary = sep_boundary + b"--\r\n" body_builder = io.BytesIO() data = args["data"] for key, value in data.items(): readable = getattr(value, "readable", None) if readable and value.readable(): filename = "Uploaded file" name_attr = getattr(value, "name", None) if name_attr: filename = name_attr.decode("utf-8") if isinstance(name_attr, bytes) else name_attr if "filename" in data: filename = data["filename"] mimetype = mimetypes.guess_type(filename)[0] or "application/octet-stream" title = ( f'\r\nContent-Disposition: form-data; name="{key}"; filename="{filename}"\r\n' + f"Content-Type: {mimetype}\r\n" ) value = value.read() else: title = f'\r\nContent-Disposition: form-data; name="{key}"\r\n' value = str(value).encode("utf-8") body_builder.write(sep_boundary) body_builder.write(title.encode("utf-8")) body_builder.write(b"\r\n") body_builder.write(value) body_builder.write(end_boundary) body = body_builder.getvalue() headers["Content-Type"] = f"multipart/form-data; boundary={boundary}" headers["Content-Length"] = len(body) elif args["params"]: body = urlencode(args["params"]) headers["Content-Type"] = "application/x-www-form-urlencoded" if isinstance(body, str): body = body.encode("utf-8") # NOTE: Intentionally ignore the `http_verb` here # Slack APIs accepts any API method requests with POST methods req = Request(method="POST", url=url, data=body, headers=headers) resp = None last_error = None retry_state = RetryState() counter_for_safety = 0 while counter_for_safety < 100: counter_for_safety += 1 # If this is a retry, the next try started here. We can reset the flag. retry_state.next_attempt_requested = False try: resp = self._perform_urllib_http_request_internal(url, req) # The resp is a 200 OK response if len(self.retry_handlers) > 0: retry_request = RetryHttpRequest.from_urllib_http_request(req) body_string = resp["body"] if isinstance(resp["body"], str) else None body_bytes = body_string.encode("utf-8") if body_string is not None else resp["body"] if body_string is not None and body_string.startswith("{"): body = json.loads(body_string) else: body = {} # type: ignore[assignment] retry_response = RetryHttpResponse( status_code=resp["status"], headers=resp["headers"], body=body, # type: ignore[arg-type] data=body_bytes, ) for handler in self.retry_handlers: if handler.can_retry(state=retry_state, request=retry_request, response=retry_response): if self._logger.level <= logging.DEBUG: self._logger.info( f"A retry handler found: {type(handler).__name__} for {req.method} {req.full_url}" ) handler.prepare_for_next_attempt( state=retry_state, request=retry_request, response=retry_response ) break if retry_state.next_attempt_requested is False: return resp except HTTPError as e: # As adding new values to HTTPError#headers can be ignored, building a new dict object here response_headers = dict(e.headers.items()) resp = {"status": e.code, "headers": response_headers} if e.code == 429: # for compatibility with aiohttp if "retry-after" not in response_headers and "Retry-After" in response_headers: response_headers["retry-after"] = response_headers["Retry-After"] if "Retry-After" not in response_headers and "retry-after" in response_headers: response_headers["Retry-After"] = response_headers["retry-after"] # read the response body here charset = e.headers.get_content_charset() or "utf-8" response_body: str = e.read().decode(charset) resp["body"] = response_body # Try to find a retry handler for this error retry_request = RetryHttpRequest.from_urllib_http_request(req) retry_response = RetryHttpResponse( status_code=e.code, headers={k: [v] for k, v in response_headers.items()}, data=response_body.encode("utf-8") if response_body is not None else None, ) for handler in self.retry_handlers: if handler.can_retry( state=retry_state, request=retry_request, response=retry_response, error=e, ): if self._logger.level <= logging.DEBUG: self._logger.info( f"A retry handler found: {type(handler).__name__} for {req.method} {req.full_url} - {e}" ) handler.prepare_for_next_attempt( state=retry_state, request=retry_request, response=retry_response, error=e, ) break if retry_state.next_attempt_requested is False: return resp except Exception as err: last_error = err self._logger.error(f"Failed to send a request to Slack API server: {err}") # Try to find a retry handler for this error retry_request = RetryHttpRequest.from_urllib_http_request(req) for handler in self.retry_handlers: if handler.can_retry( state=retry_state, request=retry_request, response=None, error=err, ): if self._logger.level <= logging.DEBUG: self._logger.info( f"A retry handler found: {type(handler).__name__} for {req.method} {req.full_url} - {err}" ) handler.prepare_for_next_attempt( state=retry_state, request=retry_request, response=None, error=err, ) self._logger.info(f"Going to retry the same request: {req.method} {req.full_url}") break if retry_state.next_attempt_requested is False: raise err if resp is not None: return resp raise last_error # type: ignore[misc] def _perform_urllib_http_request_internal( self, url: str, req: Request, ) -> Dict[str, Any]: # urllib not only opens http:// or https:// URLs, but also ftp:// and file://. # With this it might be possible to open local files on the executing machine # which might be a security risk if the URL to open can be manipulated by an external user. # (BAN-B310) if url.lower().startswith("http"): opener: Optional[OpenerDirector] = None if self.proxy is not None: if isinstance(self.proxy, str): opener = urllib.request.build_opener( ProxyHandler({"http": self.proxy, "https": self.proxy}), HTTPSHandler(context=self.ssl), ) else: raise SlackRequestError(f"Invalid proxy detected: {self.proxy} must be a str value") if opener: resp = opener.open(req, timeout=self.timeout) else: resp = urlopen(req, context=self.ssl, timeout=self.timeout) if resp.headers.get_content_type() == "application/gzip": # admin.analytics.getFile body: bytes = resp.read() if self._logger.level <= logging.DEBUG: self._logger.debug( "Received the following response - " f"status: {resp.code}, " f"headers: {dict(resp.headers)}, " f"body: (binary)" ) return {"status": resp.code, "headers": resp.headers, "body": body} charset = resp.headers.get_content_charset() or "utf-8" decoded_body: str = resp.read().decode(charset) # read the response body here if self._logger.level <= logging.DEBUG: self._logger.debug( "Received the following response - " f"status: {resp.code}, " f"headers: {dict(resp.headers)}, " f"body: {decoded_body}" ) return {"status": resp.code, "headers": resp.headers, "body": decoded_body} raise SlackRequestError(f"Invalid URL detected: {url}") def _build_urllib_request_headers( self, token: str, has_json: bool, has_files: bool, additional_headers: dict ) -> Dict[str, str]: headers = {"Content-Type": "application/x-www-form-urlencoded"} headers.update(self.headers) if token: headers.update({"Authorization": "Bearer {}".format(token)}) if additional_headers: headers.update(additional_headers) if has_json: headers.update({"Content-Type": "application/json;charset=utf-8"}) if has_files: # will be set afterward headers.pop("Content-Type", None) return headers def _upload_file( self, *, url: str, data: bytes, logger: logging.Logger, timeout: int, proxy: Optional[str], ssl: Optional[SSLContext], ) -> FileUploadV2Result: """Upload a file using the issued upload URL""" result = _upload_file_via_v2_url( url=url, data=data, logger=logger, timeout=timeout, proxy=proxy, ssl=ssl, ) return FileUploadV2Result( status=result.get("status"), # type: ignore[arg-type] body=result.get("body"), # type: ignore[arg-type] ) # ================================================================= @staticmethod def validate_slack_signature(*, signing_secret: str, data: str, timestamp: str, signature: str) -> bool: """ Slack creates a unique string for your app and shares it with you. Verify requests from Slack with confidence by verifying signatures using your signing secret. On each HTTP request that Slack sends, we add an X-Slack-Signature HTTP header. The signature is created by combining the signing secret with the body of the request we're sending using a standard HMAC-SHA256 keyed hash. https://docs.slack.dev/authentication/verifying-requests-from-slack/#how_to_make_a_request_signature_in_4_easy_steps__an_overview Args: signing_secret: Your application's signing secret, available in the Slack API dashboard data: The raw body of the incoming request - no headers, just the body. timestamp: from the 'X-Slack-Request-Timestamp' header signature: from the 'X-Slack-Signature' header - the calculated signature should match this. Returns: True if signatures matches """ warnings.warn( "As this method is deprecated since slackclient 2.6.0, " "use `from slack.signature import SignatureVerifier` instead", DeprecationWarning, ) format_req = str.encode(f"v0:{timestamp}:{data}") encoded_secret = str.encode(signing_secret) request_hash = hmac.new(encoded_secret, format_req, hashlib.sha256).hexdigest() calculated_signature = f"v0={request_hash}" return hmac.compare_digest(calculated_signature, signature)