anonymousland-synapse/synapse/http/servlet.py
Patrick Cloke 68a6717312
Reject mentions on the C-S API which are invalid. (#15311)
Invalid mentions data received over the Client-Server API should
be rejected with a 400 error. This will hopefully stop clients from
sending invalid data, although does not help with data received
over federation.
2023-03-24 08:31:14 -04:00

915 lines
25 KiB
Python

# Copyright 2014-2016 OpenMarket Ltd
#
# 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.
""" This module contains base REST classes for constructing REST servlets. """
import enum
import logging
from http import HTTPStatus
from typing import (
TYPE_CHECKING,
Iterable,
List,
Mapping,
Optional,
Sequence,
Tuple,
Type,
TypeVar,
overload,
)
from pydantic import BaseModel, MissingError, PydanticValueError, ValidationError
from pydantic.error_wrappers import ErrorWrapper
from typing_extensions import Literal
from twisted.web.server import Request
from synapse.api.errors import Codes, SynapseError
from synapse.http import redact_uri
from synapse.http.server import HttpServer
from synapse.types import JsonDict, RoomAlias, RoomID
from synapse.util import json_decoder
if TYPE_CHECKING:
from synapse.server import HomeServer
logger = logging.getLogger(__name__)
@overload
def parse_integer(request: Request, name: str, default: int) -> int:
...
@overload
def parse_integer(request: Request, name: str, *, required: Literal[True]) -> int:
...
@overload
def parse_integer(
request: Request, name: str, default: Optional[int] = None, required: bool = False
) -> Optional[int]:
...
def parse_integer(
request: Request, name: str, default: Optional[int] = None, required: bool = False
) -> Optional[int]:
"""Parse an integer parameter from the request string
Args:
request: the twisted HTTP request.
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the parameter is absent,
defaults to False.
Returns:
An int value or the default.
Raises:
SynapseError: if the parameter is absent and required, or if the
parameter is present and not an integer.
"""
args: Mapping[bytes, Sequence[bytes]] = request.args # type: ignore
return parse_integer_from_args(args, name, default, required)
@overload
def parse_integer_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[int] = None,
) -> Optional[int]:
...
@overload
def parse_integer_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
*,
required: Literal[True],
) -> int:
...
@overload
def parse_integer_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[int] = None,
required: bool = False,
) -> Optional[int]:
...
def parse_integer_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[int] = None,
required: bool = False,
) -> Optional[int]:
"""Parse an integer parameter from the request string
Args:
args: A mapping of request args as bytes to a list of bytes (e.g. request.args).
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the parameter is absent,
defaults to False.
Returns:
An int value or the default.
Raises:
SynapseError: if the parameter is absent and required, or if the
parameter is present and not an integer.
"""
name_bytes = name.encode("ascii")
if name_bytes in args:
try:
return int(args[name_bytes][0])
except Exception:
message = "Query parameter %r must be an integer" % (name,)
raise SynapseError(
HTTPStatus.BAD_REQUEST, message, errcode=Codes.INVALID_PARAM
)
else:
if required:
message = "Missing integer query parameter %r" % (name,)
raise SynapseError(
HTTPStatus.BAD_REQUEST, message, errcode=Codes.MISSING_PARAM
)
else:
return default
@overload
def parse_boolean(request: Request, name: str, default: bool) -> bool:
...
@overload
def parse_boolean(request: Request, name: str, *, required: Literal[True]) -> bool:
...
@overload
def parse_boolean(
request: Request, name: str, default: Optional[bool] = None, required: bool = False
) -> Optional[bool]:
...
def parse_boolean(
request: Request, name: str, default: Optional[bool] = None, required: bool = False
) -> Optional[bool]:
"""Parse a boolean parameter from the request query string
Args:
request: the twisted HTTP request.
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the parameter is absent,
defaults to False.
Returns:
A bool value or the default.
Raises:
SynapseError: if the parameter is absent and required, or if the
parameter is present and not one of "true" or "false".
"""
args: Mapping[bytes, Sequence[bytes]] = request.args # type: ignore
return parse_boolean_from_args(args, name, default, required)
@overload
def parse_boolean_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: bool,
) -> bool:
...
@overload
def parse_boolean_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
*,
required: Literal[True],
) -> bool:
...
@overload
def parse_boolean_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[bool] = None,
required: bool = False,
) -> Optional[bool]:
...
def parse_boolean_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[bool] = None,
required: bool = False,
) -> Optional[bool]:
"""Parse a boolean parameter from the request query string
Args:
args: A mapping of request args as bytes to a list of bytes (e.g. request.args).
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the parameter is absent,
defaults to False.
Returns:
A bool value or the default.
Raises:
SynapseError: if the parameter is absent and required, or if the
parameter is present and not one of "true" or "false".
"""
name_bytes = name.encode("ascii")
if name_bytes in args:
try:
return {b"true": True, b"false": False}[args[name_bytes][0]]
except Exception:
message = (
"Boolean query parameter %r must be one of ['true', 'false']"
) % (name,)
raise SynapseError(
HTTPStatus.BAD_REQUEST, message, errcode=Codes.INVALID_PARAM
)
else:
if required:
message = "Missing boolean query parameter %r" % (name,)
raise SynapseError(
HTTPStatus.BAD_REQUEST, message, errcode=Codes.MISSING_PARAM
)
else:
return default
@overload
def parse_bytes_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[bytes] = None,
) -> Optional[bytes]:
...
@overload
def parse_bytes_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Literal[None] = None,
*,
required: Literal[True],
) -> bytes:
...
@overload
def parse_bytes_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[bytes] = None,
required: bool = False,
) -> Optional[bytes]:
...
def parse_bytes_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[bytes] = None,
required: bool = False,
) -> Optional[bytes]:
"""
Parse a string parameter as bytes from the request query string.
Args:
args: A mapping of request args as bytes to a list of bytes (e.g. request.args).
name: the name of the query parameter.
default: value to use if the parameter is absent,
defaults to None. Must be bytes if encoding is None.
required: whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
Returns:
Bytes or the default value.
Raises:
SynapseError if the parameter is absent and required.
"""
name_bytes = name.encode("ascii")
if name_bytes in args:
return args[name_bytes][0]
elif required:
message = "Missing string query parameter %s" % (name,)
raise SynapseError(HTTPStatus.BAD_REQUEST, message, errcode=Codes.MISSING_PARAM)
return default
@overload
def parse_string(
request: Request,
name: str,
default: str,
*,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> str:
...
@overload
def parse_string(
request: Request,
name: str,
*,
required: Literal[True],
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> str:
...
@overload
def parse_string(
request: Request,
name: str,
*,
default: Optional[str] = None,
required: bool = False,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[str]:
...
def parse_string(
request: Request,
name: str,
default: Optional[str] = None,
required: bool = False,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[str]:
"""
Parse a string parameter from the request query string.
If encoding is not None, the content of the query param will be
decoded to Unicode using the encoding, otherwise it will be encoded
Args:
request: the twisted HTTP request.
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
allowed_values: List of allowed values for the
string, or None if any value is allowed, defaults to None. Must be
the same type as name, if given.
encoding: The encoding to decode the string content with.
Returns:
A string value or the default.
Raises:
SynapseError if the parameter is absent and required, or if the
parameter is present, must be one of a list of allowed values and
is not one of those allowed values.
"""
args: Mapping[bytes, Sequence[bytes]] = request.args # type: ignore
return parse_string_from_args(
args,
name,
default,
required=required,
allowed_values=allowed_values,
encoding=encoding,
)
EnumT = TypeVar("EnumT", bound=enum.Enum)
@overload
def parse_enum(
request: Request,
name: str,
E: Type[EnumT],
default: EnumT,
) -> EnumT:
...
@overload
def parse_enum(
request: Request,
name: str,
E: Type[EnumT],
*,
required: Literal[True],
) -> EnumT:
...
def parse_enum(
request: Request,
name: str,
E: Type[EnumT],
default: Optional[EnumT] = None,
required: bool = False,
) -> Optional[EnumT]:
"""
Parse an enum parameter from the request query string.
Note that the enum *must only have string values*.
Args:
request: the twisted HTTP request.
name: the name of the query parameter.
E: the enum which represents valid values
default: enum value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
Returns:
An enum value.
Raises:
SynapseError if the parameter is absent and required, or if the
parameter is present, must be one of a list of allowed values and
is not one of those allowed values.
"""
# Assert the enum values are strings.
assert all(
isinstance(e.value, str) for e in E
), "parse_enum only works with string values"
str_value = parse_string(
request,
name,
default=default.value if default is not None else None,
required=required,
allowed_values=[e.value for e in E],
)
if str_value is None:
return None
return E(str_value)
def _parse_string_value(
value: bytes,
allowed_values: Optional[Iterable[str]],
name: str,
encoding: str,
) -> str:
try:
value_str = value.decode(encoding)
except ValueError:
raise SynapseError(
HTTPStatus.BAD_REQUEST, "Query parameter %r must be %s" % (name, encoding)
)
if allowed_values is not None and value_str not in allowed_values:
message = "Query parameter %r must be one of [%s]" % (
name,
", ".join(repr(v) for v in allowed_values),
)
raise SynapseError(HTTPStatus.BAD_REQUEST, message, errcode=Codes.INVALID_PARAM)
else:
return value_str
@overload
def parse_strings_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
*,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[List[str]]:
...
@overload
def parse_strings_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: List[str],
*,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> List[str]:
...
@overload
def parse_strings_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
*,
required: Literal[True],
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> List[str]:
...
@overload
def parse_strings_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[List[str]] = None,
*,
required: bool = False,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[List[str]]:
...
def parse_strings_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[List[str]] = None,
required: bool = False,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[List[str]]:
"""
Parse a string parameter from the request query string list.
The content of the query param will be decoded to Unicode using the encoding.
Args:
args: A mapping of request args as bytes to a list of bytes (e.g. request.args).
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
allowed_values: List of allowed values for the
string, or None if any value is allowed, defaults to None.
encoding: The encoding to decode the string content with.
Returns:
A string value or the default.
Raises:
SynapseError if the parameter is absent and required, or if the
parameter is present, must be one of a list of allowed values and
is not one of those allowed values.
"""
name_bytes = name.encode("ascii")
if name_bytes in args:
values = args[name_bytes]
return [
_parse_string_value(value, allowed_values, name=name, encoding=encoding)
for value in values
]
else:
if required:
message = "Missing string query parameter %r" % (name,)
raise SynapseError(
HTTPStatus.BAD_REQUEST, message, errcode=Codes.MISSING_PARAM
)
return default
@overload
def parse_string_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[str] = None,
*,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[str]:
...
@overload
def parse_string_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[str] = None,
*,
required: Literal[True],
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> str:
...
@overload
def parse_string_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[str] = None,
required: bool = False,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[str]:
...
def parse_string_from_args(
args: Mapping[bytes, Sequence[bytes]],
name: str,
default: Optional[str] = None,
required: bool = False,
allowed_values: Optional[Iterable[str]] = None,
encoding: str = "ascii",
) -> Optional[str]:
"""
Parse the string parameter from the request query string list
and return the first result.
The content of the query param will be decoded to Unicode using the encoding.
Args:
args: A mapping of request args as bytes to a list of bytes (e.g. request.args).
name: the name of the query parameter.
default: value to use if the parameter is absent, defaults to None.
required: whether to raise a 400 SynapseError if the
parameter is absent, defaults to False.
allowed_values: List of allowed values for the
string, or None if any value is allowed, defaults to None. Must be
the same type as name, if given.
encoding: The encoding to decode the string content with.
Returns:
A string value or the default.
Raises:
SynapseError if the parameter is absent and required, or if the
parameter is present, must be one of a list of allowed values and
is not one of those allowed values.
"""
strings = parse_strings_from_args(
args,
name,
default=[default] if default is not None else None,
required=required,
allowed_values=allowed_values,
encoding=encoding,
)
if strings is None:
return None
return strings[0]
@overload
def parse_json_value_from_request(request: Request) -> JsonDict:
...
@overload
def parse_json_value_from_request(
request: Request, allow_empty_body: Literal[False]
) -> JsonDict:
...
@overload
def parse_json_value_from_request(
request: Request, allow_empty_body: bool = False
) -> Optional[JsonDict]:
...
def parse_json_value_from_request(
request: Request, allow_empty_body: bool = False
) -> Optional[JsonDict]:
"""Parse a JSON value from the body of a twisted HTTP request.
Args:
request: the twisted HTTP request.
allow_empty_body: if True, an empty body will be accepted and turned into None
Returns:
The JSON value.
Raises:
SynapseError if the request body couldn't be decoded as JSON.
"""
try:
content_bytes = request.content.read() # type: ignore
except Exception:
raise SynapseError(HTTPStatus.BAD_REQUEST, "Error reading JSON content.")
if not content_bytes and allow_empty_body:
return None
try:
content = json_decoder.decode(content_bytes.decode("utf-8"))
except Exception as e:
logger.warning(
"Unable to parse JSON from %s %s response: %s (%s)",
request.method.decode("ascii", errors="replace"),
redact_uri(request.uri.decode("ascii", errors="replace")),
e,
content_bytes,
)
raise SynapseError(
HTTPStatus.BAD_REQUEST, "Content not JSON.", errcode=Codes.NOT_JSON
)
return content
def parse_json_object_from_request(
request: Request, allow_empty_body: bool = False
) -> JsonDict:
"""Parse a JSON object from the body of a twisted HTTP request.
Args:
request: the twisted HTTP request.
allow_empty_body: if True, an empty body will be accepted and turned into
an empty dict.
Raises:
SynapseError if the request body couldn't be decoded as JSON or
if it wasn't a JSON object.
"""
content = parse_json_value_from_request(request, allow_empty_body=allow_empty_body)
if allow_empty_body and content is None:
return {}
if not isinstance(content, dict):
message = "Content must be a JSON object."
raise SynapseError(HTTPStatus.BAD_REQUEST, message, errcode=Codes.BAD_JSON)
return content
Model = TypeVar("Model", bound=BaseModel)
def validate_json_object(content: JsonDict, model_type: Type[Model]) -> Model:
"""Validate a deserialized JSON object using the given pydantic model.
Raises:
SynapseError if the request body couldn't be decoded as JSON or
if it wasn't a JSON object.
"""
try:
instance = model_type.parse_obj(content)
except ValidationError as e:
# Choose a matrix error code. The catch-all is BAD_JSON, but we try to find a
# more specific error if possible (which occasionally helps us to be spec-
# compliant) This is a bit awkward because the spec's error codes aren't very
# clear-cut: BAD_JSON arguably overlaps with MISSING_PARAM and INVALID_PARAM.
errcode = Codes.BAD_JSON
raw_errors = e.raw_errors
if len(raw_errors) == 1 and isinstance(raw_errors[0], ErrorWrapper):
raw_error = raw_errors[0].exc
if isinstance(raw_error, MissingError):
errcode = Codes.MISSING_PARAM
elif isinstance(raw_error, PydanticValueError):
errcode = Codes.INVALID_PARAM
raise SynapseError(HTTPStatus.BAD_REQUEST, str(e), errcode=errcode)
return instance
def parse_and_validate_json_object_from_request(
request: Request, model_type: Type[Model]
) -> Model:
"""Parse a JSON object from the body of a twisted HTTP request, then deserialise and
validate using the given pydantic model.
Raises:
SynapseError if the request body couldn't be decoded as JSON or
if it wasn't a JSON object.
"""
content = parse_json_object_from_request(request, allow_empty_body=False)
return validate_json_object(content, model_type)
def assert_params_in_dict(body: JsonDict, required: Iterable[str]) -> None:
absent = []
for k in required:
if k not in body:
absent.append(k)
if len(absent) > 0:
raise SynapseError(
HTTPStatus.BAD_REQUEST, "Missing params: %r" % absent, Codes.MISSING_PARAM
)
class RestServlet:
"""A Synapse REST Servlet.
An implementing class can either provide its own custom 'register' method,
or use the automatic pattern handling provided by the base class.
To use this latter, the implementing class instead provides a `PATTERN`
class attribute containing a pre-compiled regular expression. The automatic
register method will then use this method to register any of the following
instance methods associated with the corresponding HTTP method:
on_GET
on_PUT
on_POST
on_DELETE
Automatically handles turning CodeMessageExceptions thrown by these methods
into the appropriate HTTP response.
"""
def register(self, http_server: HttpServer) -> None:
"""Register this servlet with the given HTTP server."""
patterns = getattr(self, "PATTERNS", None)
if patterns:
for method in ("GET", "PUT", "POST", "DELETE"):
if hasattr(self, "on_%s" % (method,)):
servlet_classname = self.__class__.__name__
method_handler = getattr(self, "on_%s" % (method,))
http_server.register_paths(
method, patterns, method_handler, servlet_classname
)
else:
raise NotImplementedError("RestServlet must register something.")
class ResolveRoomIdMixin:
def __init__(self, hs: "HomeServer"):
self.room_member_handler = hs.get_room_member_handler()
async def resolve_room_id(
self, room_identifier: str, remote_room_hosts: Optional[List[str]] = None
) -> Tuple[str, Optional[List[str]]]:
"""
Resolve a room identifier to a room ID, if necessary.
This also performanes checks to ensure the room ID is of the proper form.
Args:
room_identifier: The room ID or alias.
remote_room_hosts: The potential remote room hosts to use.
Returns:
The resolved room ID.
Raises:
SynapseError if the room ID is of the wrong form.
"""
if RoomID.is_valid(room_identifier):
resolved_room_id = room_identifier
elif RoomAlias.is_valid(room_identifier):
room_alias = RoomAlias.from_string(room_identifier)
(
room_id,
remote_room_hosts,
) = await self.room_member_handler.lookup_room_alias(room_alias)
resolved_room_id = room_id.to_string()
else:
raise SynapseError(
HTTPStatus.BAD_REQUEST,
"%s was not legal room ID or room alias" % (room_identifier,),
)
if not resolved_room_id:
raise SynapseError(
HTTPStatus.BAD_REQUEST,
"Unknown room ID or room alias %s" % room_identifier,
)
return resolved_room_id, remote_room_hosts