import base64 import binascii import logging import os import random import secrets import shutil from datetime import timedelta from typing import IO, Any, Callable, Literal, Optional from django.conf import settings from django.core.signing import BadSignature, TimestampSigner from django.urls import reverse from zerver.lib.avatar_hash import user_avatar_path from zerver.lib.upload.base import ( MEDIUM_AVATAR_SIZE, ZulipUploadBackend, create_attachment, resize_avatar, resize_emoji, resize_logo, sanitize_name, ) from zerver.lib.utils import assert_is_not_none from zerver.models import Realm, RealmEmoji, UserProfile def assert_is_local_storage_path(type: Literal["avatars", "files"], full_path: str) -> None: """ Verify that we are only reading and writing files under the expected paths. This is expected to be already enforced at other layers, via cleaning of user input, but we assert it here for defense in depth. """ assert settings.LOCAL_UPLOADS_DIR is not None type_path = os.path.join(settings.LOCAL_UPLOADS_DIR, type) assert os.path.commonpath([type_path, full_path]) == type_path def write_local_file(type: Literal["avatars", "files"], path: str, file_data: bytes) -> None: file_path = os.path.join(assert_is_not_none(settings.LOCAL_UPLOADS_DIR), type, path) assert_is_local_storage_path(type, file_path) os.makedirs(os.path.dirname(file_path), exist_ok=True) with open(file_path, "wb") as f: f.write(file_data) def read_local_file(type: Literal["avatars", "files"], path: str) -> bytes: file_path = os.path.join(assert_is_not_none(settings.LOCAL_UPLOADS_DIR), type, path) assert_is_local_storage_path(type, file_path) with open(file_path, "rb") as f: return f.read() def delete_local_file(type: Literal["avatars", "files"], path: str) -> bool: file_path = os.path.join(assert_is_not_none(settings.LOCAL_UPLOADS_DIR), type, path) assert_is_local_storage_path(type, file_path) if os.path.isfile(file_path): # This removes the file but the empty folders still remain. os.remove(file_path) return True file_name = path.split("/")[-1] logging.warning("%s does not exist. Its entry in the database will be removed.", file_name) return False def get_local_file_path(path_id: str) -> Optional[str]: local_path = os.path.join(assert_is_not_none(settings.LOCAL_UPLOADS_DIR), "files", path_id) assert_is_local_storage_path("files", local_path) if os.path.isfile(local_path): return local_path else: return None LOCAL_FILE_ACCESS_TOKEN_SALT = "local_file_" def generate_unauthed_file_access_url(path_id: str) -> str: signed_data = TimestampSigner(salt=LOCAL_FILE_ACCESS_TOKEN_SALT).sign(path_id) token = base64.b16encode(signed_data.encode()).decode() filename = path_id.split("/")[-1] return reverse("local_file_unauthed", args=[token, filename]) def get_local_file_path_id_from_token(token: str) -> Optional[str]: signer = TimestampSigner(salt=LOCAL_FILE_ACCESS_TOKEN_SALT) try: signed_data = base64.b16decode(token).decode() path_id = signer.unsign(signed_data, max_age=timedelta(seconds=60)) except (BadSignature, binascii.Error): return None return path_id class LocalUploadBackend(ZulipUploadBackend): def get_public_upload_root_url(self) -> str: return "/user_avatars/" def generate_message_upload_path(self, realm_id: str, uploaded_file_name: str) -> str: # Split into 256 subdirectories to prevent directories from getting too big return "/".join( [ realm_id, format(random.randint(0, 255), "x"), secrets.token_urlsafe(18), sanitize_name(uploaded_file_name), ] ) def upload_message_file( self, uploaded_file_name: str, uploaded_file_size: int, content_type: Optional[str], file_data: bytes, user_profile: UserProfile, target_realm: Optional[Realm] = None, ) -> str: if target_realm is None: target_realm = user_profile.realm path = self.generate_message_upload_path(str(target_realm.id), uploaded_file_name) write_local_file("files", path, file_data) create_attachment(uploaded_file_name, path, user_profile, target_realm, uploaded_file_size) return "/user_uploads/" + path def delete_message_image(self, path_id: str) -> bool: return delete_local_file("files", path_id) def write_avatar_images(self, file_path: str, image_data: bytes) -> None: write_local_file("avatars", file_path + ".original", image_data) resized_data = resize_avatar(image_data) write_local_file("avatars", file_path + ".png", resized_data) resized_medium = resize_avatar(image_data, MEDIUM_AVATAR_SIZE) write_local_file("avatars", file_path + "-medium.png", resized_medium) def upload_avatar_image( self, user_file: IO[bytes], acting_user_profile: UserProfile, target_user_profile: UserProfile, content_type: Optional[str] = None, ) -> None: file_path = user_avatar_path(target_user_profile) image_data = user_file.read() self.write_avatar_images(file_path, image_data) def delete_avatar_image(self, user: UserProfile) -> None: path_id = user_avatar_path(user) delete_local_file("avatars", path_id + ".original") delete_local_file("avatars", path_id + ".png") delete_local_file("avatars", path_id + "-medium.png") def get_avatar_url(self, hash_key: str, medium: bool = False) -> str: medium_suffix = "-medium" if medium else "" return f"/user_avatars/{hash_key}{medium_suffix}.png" def copy_avatar(self, source_profile: UserProfile, target_profile: UserProfile) -> None: source_file_path = user_avatar_path(source_profile) target_file_path = user_avatar_path(target_profile) image_data = read_local_file("avatars", source_file_path + ".original") self.write_avatar_images(target_file_path, image_data) def realm_avatar_and_logo_path(self, realm: Realm) -> str: return os.path.join(str(realm.id), "realm") def upload_realm_icon_image(self, icon_file: IO[bytes], user_profile: UserProfile) -> None: upload_path = self.realm_avatar_and_logo_path(user_profile.realm) image_data = icon_file.read() write_local_file("avatars", os.path.join(upload_path, "icon.original"), image_data) resized_data = resize_avatar(image_data) write_local_file("avatars", os.path.join(upload_path, "icon.png"), resized_data) def get_realm_icon_url(self, realm_id: int, version: int) -> str: return f"/user_avatars/{realm_id}/realm/icon.png?version={version}" def upload_realm_logo_image( self, logo_file: IO[bytes], user_profile: UserProfile, night: bool ) -> None: upload_path = self.realm_avatar_and_logo_path(user_profile.realm) if night: original_file = "night_logo.original" resized_file = "night_logo.png" else: original_file = "logo.original" resized_file = "logo.png" image_data = logo_file.read() write_local_file("avatars", os.path.join(upload_path, original_file), image_data) resized_data = resize_logo(image_data) write_local_file("avatars", os.path.join(upload_path, resized_file), resized_data) def get_realm_logo_url(self, realm_id: int, version: int, night: bool) -> str: if night: file_name = "night_logo.png" else: file_name = "logo.png" return f"/user_avatars/{realm_id}/realm/{file_name}?version={version}" def ensure_avatar_image(self, user_profile: UserProfile, is_medium: bool = False) -> None: file_extension = "-medium.png" if is_medium else ".png" file_path = user_avatar_path(user_profile) output_path = os.path.join( assert_is_not_none(settings.LOCAL_UPLOADS_DIR), "avatars", file_path + file_extension, ) if os.path.isfile(output_path): return image_path = os.path.join( assert_is_not_none(settings.LOCAL_UPLOADS_DIR), "avatars", file_path + ".original" ) with open(image_path, "rb") as f: image_data = f.read() if is_medium: resized_avatar = resize_avatar(image_data, MEDIUM_AVATAR_SIZE) else: resized_avatar = resize_avatar(image_data) write_local_file("avatars", file_path + file_extension, resized_avatar) def upload_emoji_image( self, emoji_file: IO[bytes], emoji_file_name: str, user_profile: UserProfile ) -> bool: emoji_path = RealmEmoji.PATH_ID_TEMPLATE.format( realm_id=user_profile.realm_id, emoji_file_name=emoji_file_name, ) image_data = emoji_file.read() write_local_file("avatars", ".".join((emoji_path, "original")), image_data) resized_image_data, is_animated, still_image_data = resize_emoji(image_data) write_local_file("avatars", emoji_path, resized_image_data) if is_animated: assert still_image_data is not None still_path = RealmEmoji.STILL_PATH_ID_TEMPLATE.format( realm_id=user_profile.realm_id, emoji_filename_without_extension=os.path.splitext(emoji_file_name)[0], ) write_local_file("avatars", still_path, still_image_data) return is_animated def get_emoji_url(self, emoji_file_name: str, realm_id: int, still: bool = False) -> str: if still: return os.path.join( "/user_avatars", RealmEmoji.STILL_PATH_ID_TEMPLATE.format( realm_id=realm_id, emoji_filename_without_extension=os.path.splitext(emoji_file_name)[0], ), ) else: return os.path.join( "/user_avatars", RealmEmoji.PATH_ID_TEMPLATE.format( realm_id=realm_id, emoji_file_name=emoji_file_name ), ) def upload_export_tarball( self, realm: Realm, tarball_path: str, percent_callback: Optional[Callable[[Any], None]] = None, ) -> str: path = os.path.join( "exports", str(realm.id), secrets.token_urlsafe(18), os.path.basename(tarball_path), ) abs_path = os.path.join(assert_is_not_none(settings.LOCAL_UPLOADS_DIR), "avatars", path) os.makedirs(os.path.dirname(abs_path), exist_ok=True) shutil.copy(tarball_path, abs_path) public_url = realm.uri + "/user_avatars/" + path return public_url def delete_export_tarball(self, export_path: str) -> Optional[str]: # Get the last element of a list in the form ['user_avatars', ''] assert export_path.startswith("/") file_path = export_path[1:].split("/", 1)[-1] if delete_local_file("avatars", file_path): return export_path return None def get_export_tarball_url(self, realm: Realm, export_path: str) -> str: # export_path has a leading `/` return realm.uri + export_path