diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/config/homeserver.py | 2 | ||||
| -rw-r--r-- | synapse/config/oembed.py | 180 | ||||
| -rw-r--r-- | synapse/res/providers.json | 17 | ||||
| -rw-r--r-- | synapse/rest/media/v1/oembed.py | 135 | ||||
| -rw-r--r-- | synapse/rest/media/v1/preview_url_resource.py | 147 |
5 files changed, 339 insertions, 142 deletions
diff --git a/synapse/config/homeserver.py b/synapse/config/homeserver.py index 1f42a51857..442f1b9ac0 100644 --- a/synapse/config/homeserver.py +++ b/synapse/config/homeserver.py @@ -30,6 +30,7 @@ from .key import KeyConfig from .logger import LoggingConfig from .metrics import MetricsConfig from .modules import ModulesConfig +from .oembed import OembedConfig from .oidc import OIDCConfig from .password_auth_providers import PasswordAuthProviderConfig from .push import PushConfig @@ -65,6 +66,7 @@ class HomeServerConfig(RootConfig): LoggingConfig, RatelimitConfig, ContentRepositoryConfig, + OembedConfig, CaptchaConfig, VoipConfig, RegistrationConfig, diff --git a/synapse/config/oembed.py b/synapse/config/oembed.py new file mode 100644 index 0000000000..09267b5eef --- /dev/null +++ b/synapse/config/oembed.py @@ -0,0 +1,180 @@ +# Copyright 2021 The Matrix.org Foundation C.I.C. +# +# 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. +import json +import re +from typing import Any, Dict, Iterable, List, Pattern +from urllib import parse as urlparse + +import attr +import pkg_resources + +from synapse.types import JsonDict + +from ._base import Config, ConfigError +from ._util import validate_config + + +@attr.s(slots=True, frozen=True, auto_attribs=True) +class OEmbedEndpointConfig: + # The API endpoint to fetch. + api_endpoint: str + # The patterns to match. + url_patterns: List[Pattern] + + +class OembedConfig(Config): + """oEmbed Configuration""" + + section = "oembed" + + def read_config(self, config, **kwargs): + oembed_config: Dict[str, Any] = config.get("oembed") or {} + + # A list of patterns which will be used. + self.oembed_patterns: List[OEmbedEndpointConfig] = list( + self._parse_and_validate_providers(oembed_config) + ) + + def _parse_and_validate_providers( + self, oembed_config: dict + ) -> Iterable[OEmbedEndpointConfig]: + """Extract and parse the oEmbed providers from the given JSON file. + + Returns a generator which yields the OidcProviderConfig objects + """ + # Whether to use the packaged providers.json file. + if not oembed_config.get("disable_default_providers") or False: + providers = json.load( + pkg_resources.resource_stream("synapse", "res/providers.json") + ) + yield from self._parse_and_validate_provider( + providers, config_path=("oembed",) + ) + + # The JSON files which includes additional provider information. + for i, file in enumerate(oembed_config.get("additional_providers") or []): + # TODO Error checking. + with open(file) as f: + providers = json.load(f) + + yield from self._parse_and_validate_provider( + providers, + config_path=( + "oembed", + "additional_providers", + f"<item {i}>", + ), + ) + + def _parse_and_validate_provider( + self, providers: List[JsonDict], config_path: Iterable[str] + ) -> Iterable[OEmbedEndpointConfig]: + # Ensure it is the proper form. + validate_config( + _OEMBED_PROVIDER_SCHEMA, + providers, + config_path=config_path, + ) + + # Parse it and yield each result. + for provider in providers: + # Each provider might have multiple API endpoints, each which + # might have multiple patterns to match. + for endpoint in provider["endpoints"]: + api_endpoint = endpoint["url"] + patterns = [ + self._glob_to_pattern(glob, config_path) + for glob in endpoint["schemes"] + ] + yield OEmbedEndpointConfig(api_endpoint, patterns) + + def _glob_to_pattern(self, glob: str, config_path: Iterable[str]) -> Pattern: + """ + Convert the glob into a sane regular expression to match against. The + rules followed will be slightly different for the domain portion vs. + the rest. + + 1. The scheme must be one of HTTP / HTTPS (and have no globs). + 2. The domain can have globs, but we limit it to characters that can + reasonably be a domain part. + TODO: This does not attempt to handle Unicode domain names. + TODO: The domain should not allow wildcard TLDs. + 3. Other parts allow a glob to be any one, or more, characters. + """ + results = urlparse.urlparse(glob) + + # Ensure the scheme does not have wildcards (and is a sane scheme). + if results.scheme not in {"http", "https"}: + raise ConfigError(f"Insecure oEmbed scheme: {results.scheme}", config_path) + + pattern = urlparse.urlunparse( + [ + results.scheme, + re.escape(results.netloc).replace("\\*", "[a-zA-Z0-9_-]+"), + ] + + [re.escape(part).replace("\\*", ".+") for part in results[2:]] + ) + return re.compile(pattern) + + def generate_config_section(self, **kwargs): + return """\ + # oEmbed allows for easier embedding content from a website. It can be + # used for generating URLs previews of services which support it. + # + oembed: + # A default list of oEmbed providers is included with Synapse. + # + # Uncomment the following to disable using these default oEmbed URLs. + # Defaults to 'false'. + # + #disable_default_providers: true + + # Additional files with oEmbed configuration (each should be in the + # form of providers.json). + # + # By default, this list is empty (so only the default providers.json + # is used). + # + #additional_providers: + # - oembed/my_providers.json + """ + + +_OEMBED_PROVIDER_SCHEMA = { + "type": "array", + "items": { + "type": "object", + "properties": { + "provider_name": {"type": "string"}, + "provider_url": {"type": "string"}, + "endpoints": { + "type": "array", + "items": { + "type": "object", + "properties": { + "schemes": { + "type": "array", + "items": {"type": "string"}, + }, + "url": {"type": "string"}, + "formats": {"type": "array", "items": {"type": "string"}}, + "discovery": {"type": "boolean"}, + }, + "required": ["schemes", "url"], + }, + }, + }, + "required": ["provider_name", "provider_url", "endpoints"], + }, +} diff --git a/synapse/res/providers.json b/synapse/res/providers.json new file mode 100644 index 0000000000..f1838f9559 --- /dev/null +++ b/synapse/res/providers.json @@ -0,0 +1,17 @@ +[ + { + "provider_name": "Twitter", + "provider_url": "http://www.twitter.com/", + "endpoints": [ + { + "schemes": [ + "https://twitter.com/*/status/*", + "https://*.twitter.com/*/status/*", + "https://twitter.com/*/moments/*", + "https://*.twitter.com/*/moments/*" + ], + "url": "https://publish.twitter.com/oembed" + } + ] + } +] \ No newline at end of file diff --git a/synapse/rest/media/v1/oembed.py b/synapse/rest/media/v1/oembed.py new file mode 100644 index 0000000000..afe41823e4 --- /dev/null +++ b/synapse/rest/media/v1/oembed.py @@ -0,0 +1,135 @@ +# Copyright 2021 The Matrix.org Foundation C.I.C. +# +# 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. +import logging +from typing import TYPE_CHECKING, Optional + +import attr + +from synapse.http.client import SimpleHttpClient + +if TYPE_CHECKING: + from synapse.server import HomeServer + +logger = logging.getLogger(__name__) + + +@attr.s(slots=True, auto_attribs=True) +class OEmbedResult: + # Either HTML content or URL must be provided. + html: Optional[str] + url: Optional[str] + title: Optional[str] + # Number of seconds to cache the content. + cache_age: int + + +class OEmbedError(Exception): + """An error occurred processing the oEmbed object.""" + + +class OEmbedProvider: + """ + A helper for accessing oEmbed content. + + It can be used to check if a URL should be accessed via oEmbed and for + requesting/parsing oEmbed content. + """ + + def __init__(self, hs: "HomeServer", client: SimpleHttpClient): + self._oembed_patterns = {} + for oembed_endpoint in hs.config.oembed.oembed_patterns: + for pattern in oembed_endpoint.url_patterns: + self._oembed_patterns[pattern] = oembed_endpoint.api_endpoint + self._client = client + + def get_oembed_url(self, url: str) -> Optional[str]: + """ + Check whether the URL should be downloaded as oEmbed content instead. + + Args: + url: The URL to check. + + Returns: + A URL to use instead or None if the original URL should be used. + """ + for url_pattern, endpoint in self._oembed_patterns.items(): + if url_pattern.fullmatch(url): + return endpoint + + # No match. + return None + + async def get_oembed_content(self, endpoint: str, url: str) -> OEmbedResult: + """ + Request content from an oEmbed endpoint. + + Args: + endpoint: The oEmbed API endpoint. + url: The URL to pass to the API. + + Returns: + An object representing the metadata returned. + + Raises: + OEmbedError if fetching or parsing of the oEmbed information fails. + """ + try: + logger.debug("Trying to get oEmbed content for url '%s'", url) + result = await self._client.get_json( + endpoint, + # TODO Specify max height / width. + # Note that only the JSON format is supported. + args={"url": url}, + ) + + # Ensure there's a version of 1.0. + if result.get("version") != "1.0": + raise OEmbedError("Invalid version: %s" % (result.get("version"),)) + + oembed_type = result.get("type") + + # Ensure the cache age is None or an int. + cache_age = result.get("cache_age") + if cache_age: + cache_age = int(cache_age) + + oembed_result = OEmbedResult(None, None, result.get("title"), cache_age) + + # HTML content. + if oembed_type == "rich": + oembed_result.html = result.get("html") + return oembed_result + + if oembed_type == "photo": + oembed_result.url = result.get("url") + return oembed_result + + # TODO Handle link and video types. + + if "thumbnail_url" in result: + oembed_result.url = result.get("thumbnail_url") + return oembed_result + + raise OEmbedError("Incompatible oEmbed information.") + + except OEmbedError as e: + # Trap OEmbedErrors first so we can directly re-raise them. + logger.warning("Error parsing oEmbed metadata from %s: %r", url, e) + raise + + except Exception as e: + # Trap any exception and let the code follow as usual. + # FIXME: pass through 404s and other error messages nicely + logger.warning("Error downloading oEmbed metadata from %s: %r", url, e) + raise OEmbedError() from e diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py index 0f051d4041..317d333b12 100644 --- a/synapse/rest/media/v1/preview_url_resource.py +++ b/synapse/rest/media/v1/preview_url_resource.py @@ -25,8 +25,6 @@ import traceback from typing import TYPE_CHECKING, Any, Dict, Generator, Iterable, Optional, Union from urllib import parse as urlparse -import attr - from twisted.internet.error import DNSLookupError from twisted.web.server import Request @@ -43,6 +41,7 @@ from synapse.logging.context import make_deferred_yieldable, run_in_background from synapse.metrics.background_process_metrics import run_as_background_process from synapse.rest.media.v1._base import get_filename_from_headers from synapse.rest.media.v1.media_storage import MediaStorage +from synapse.rest.media.v1.oembed import OEmbedError, OEmbedProvider from synapse.util import json_encoder from synapse.util.async_helpers import ObservableDeferred from synapse.util.caches.expiringcache import ExpiringCache @@ -71,63 +70,6 @@ OG_TAG_VALUE_MAXLEN = 1000 ONE_HOUR = 60 * 60 * 1000 -# A map of globs to API endpoints. -_oembed_globs = { - # Twitter. - "https://publish.twitter.com/oembed": [ - "https://twitter.com/*/status/*", - "https://*.twitter.com/*/status/*", - "https://twitter.com/*/moments/*", - "https://*.twitter.com/*/moments/*", - # Include the HTTP versions too. - "http://twitter.com/*/status/*", - "http://*.twitter.com/*/status/*", - "http://twitter.com/*/moments/*", - "http://*.twitter.com/*/moments/*", - ], -} -# Convert the globs to regular expressions. -_oembed_patterns = {} -for endpoint, globs in _oembed_globs.items(): - for glob in globs: - # Convert the glob into a sane regular expression to match against. The - # rules followed will be slightly different for the domain portion vs. - # the rest. - # - # 1. The scheme must be one of HTTP / HTTPS (and have no globs). - # 2. The domain can have globs, but we limit it to characters that can - # reasonably be a domain part. - # TODO: This does not attempt to handle Unicode domain names. - # 3. Other parts allow a glob to be any one, or more, characters. - results = urlparse.urlparse(glob) - - # Ensure the scheme does not have wildcards (and is a sane scheme). - if results.scheme not in {"http", "https"}: - raise ValueError("Insecure oEmbed glob scheme: %s" % (results.scheme,)) - - pattern = urlparse.urlunparse( - [ - results.scheme, - re.escape(results.netloc).replace("\\*", "[a-zA-Z0-9_-]+"), - ] - + [re.escape(part).replace("\\*", ".+") for part in results[2:]] - ) - _oembed_patterns[re.compile(pattern)] = endpoint - - -@attr.s(slots=True) -class OEmbedResult: - # Either HTML content or URL must be provided. - html = attr.ib(type=Optional[str]) - url = attr.ib(type=Optional[str]) - title = attr.ib(type=Optional[str]) - # Number of seconds to cache the content. - cache_age = attr.ib(type=int) - - -class OEmbedError(Exception): - """An error occurred processing the oEmbed object.""" - class PreviewUrlResource(DirectServeJsonResource): isLeaf = True @@ -157,6 +99,8 @@ class PreviewUrlResource(DirectServeJsonResource): self.primary_base_path = media_repo.primary_base_path self.media_storage = media_storage + self._oembed = OEmbedProvider(hs, self.client) + # We run the background jobs if we're the instance specified (or no # instance is specified, where we assume there is only one instance # serving media). @@ -367,87 +311,6 @@ class PreviewUrlResource(DirectServeJsonResource): return jsonog.encode("utf8") - def _get_oembed_url(self, url: str) -> Optional[str]: - """ - Check whether the URL should be downloaded as oEmbed content instead. - - Args: - url: The URL to check. - - Returns: - A URL to use instead or None if the original URL should be used. - """ - for url_pattern, endpoint in _oembed_patterns.items(): - if url_pattern.fullmatch(url): - return endpoint - - # No match. - return None - - async def _get_oembed_content(self, endpoint: str, url: str) -> OEmbedResult: - """ - Request content from an oEmbed endpoint. - - Args: - endpoint: The oEmbed API endpoint. - url: The URL to pass to the API. - - Returns: - An object representing the metadata returned. - - Raises: - OEmbedError if fetching or parsing of the oEmbed information fails. - """ - try: - logger.debug("Trying to get oEmbed content for url '%s'", url) - result = await self.client.get_json( - endpoint, - # TODO Specify max height / width. - # Note that only the JSON format is supported. - args={"url": url}, - ) - - # Ensure there's a version of 1.0. - if result.get("version") != "1.0": - raise OEmbedError("Invalid version: %s" % (result.get("version"),)) - - oembed_type = result.get("type") - - # Ensure the cache age is None or an int. - cache_age = result.get("cache_age") - if cache_age: - cache_age = int(cache_age) - - oembed_result = OEmbedResult(None, None, result.get("title"), cache_age) - - # HTML content. - if oembed_type == "rich": - oembed_result.html = result.get("html") - return oembed_result - - if oembed_type == "photo": - oembed_result.url = result.get("url") - return oembed_result - - # TODO Handle link and video types. - - if "thumbnail_url" in result: - oembed_result.url = result.get("thumbnail_url") - return oembed_result - - raise OEmbedError("Incompatible oEmbed information.") - - except OEmbedError as e: - # Trap OEmbedErrors first so we can directly re-raise them. - logger.warning("Error parsing oEmbed metadata from %s: %r", url, e) - raise - - except Exception as e: - # Trap any exception and let the code follow as usual. - # FIXME: pass through 404s and other error messages nicely - logger.warning("Error downloading oEmbed metadata from %s: %r", url, e) - raise OEmbedError() from e - async def _download_url(self, url: str, user: str) -> Dict[str, Any]: # TODO: we should probably honour robots.txt... except in practice # we're most likely being explicitly triggered by a human rather than a @@ -459,11 +322,11 @@ class PreviewUrlResource(DirectServeJsonResource): # If this URL can be accessed via oEmbed, use that instead. url_to_download: Optional[str] = url - oembed_url = self._get_oembed_url(url) + oembed_url = self._oembed.get_oembed_url(url) if oembed_url: # The result might be a new URL to download, or it might be HTML content. try: - oembed_result = await self._get_oembed_content(oembed_url, url) + oembed_result = await self._oembed.get_oembed_content(oembed_url, url) if oembed_result.url: url_to_download = oembed_result.url elif oembed_result.html: |