Adafruit_CircuitPython_HTTP.../adafruit_httpserver/interfaces.py
2025-05-16 16:11:43 +00:00

153 lines
4.3 KiB
Python

# SPDX-FileCopyrightText: Copyright (c) 2023 Michał Pokusa
#
# SPDX-License-Identifier: MIT
"""
`adafruit_httpserver.interfaces`
====================================================
* Author(s): Michał Pokusa
"""
try:
from typing import Any, Dict, List, Tuple, Union
except ImportError:
pass
class _ISocket:
"""A class for typing necessary methods for a socket object."""
def accept(self) -> Tuple["_ISocket", Tuple[str, int]]: ...
def bind(self, address: Tuple[str, int]) -> None: ...
def setblocking(self, flag: bool) -> None: ...
def settimeout(self, value: "Union[float, None]") -> None: ...
def setsockopt(self, level: int, optname: int, value: int) -> None: ...
def listen(self, backlog: int) -> None: ...
def send(self, data: bytes) -> int: ...
def recv_into(self, buffer: memoryview, nbytes: int) -> int: ...
def close(self) -> None: ...
class _ISocketPool:
"""A class to typing necessary methods and properties for a socket pool object."""
AF_INET: int
SO_REUSEADDR: int
SOCK_STREAM: int
SOL_SOCKET: int
def socket(
self,
family: int = ...,
type: int = ...,
proto: int = ...,
) -> _ISocket: ...
def getaddrinfo(
self,
host: str,
port: int,
family: int = ...,
type: int = ...,
proto: int = ...,
flags: int = ...,
) -> Tuple[int, int, int, str, Tuple[str, int]]: ...
class _IFieldStorage:
"""Interface with shared methods for QueryParams, FormData and Headers."""
_storage: Dict[str, List[Any]]
def _add_field_value(self, field_name: str, value: Any) -> None:
if field_name not in self._storage:
self._storage[field_name] = [value]
else:
self._storage[field_name].append(value)
def get(self, field_name: str, default: Any = None) -> Union[Any, None]:
"""Get the value of a field."""
return self._storage.get(field_name, [default])[0]
def get_list(self, field_name: str) -> List[Any]:
"""Get the list of values of a field."""
return self._storage.get(field_name, [])
@property
def fields(self):
"""Returns a list of field names."""
return list(self._storage.keys())
def items(self):
"""Returns a list of (name, value) tuples."""
return [(key, value) for key in self.fields for value in self.get_list(key)]
def keys(self):
"""Returns a list of header names."""
return self.fields
def values(self):
"""Returns a list of header values."""
return [value for key in self.keys() for value in self.get_list(key)]
def __getitem__(self, field_name: str):
return self._storage[field_name][0]
def __iter__(self):
return iter(self._storage)
def __len__(self) -> int:
return len(self._storage)
def __contains__(self, key: str) -> bool:
return key in self._storage
def __repr__(self) -> str:
return f"<{self.__class__.__name__} {repr(self._storage)}>"
def _encode_html_entities(value: Union[str, None]) -> Union[str, None]:
"""Encodes unsafe HTML characters that could enable XSS attacks."""
if value is None:
return None
return (
str(value)
.replace("&", "&amp;")
.replace("<", "&lt;")
.replace(">", "&gt;")
.replace('"', "&quot;")
.replace("'", "&apos;")
)
class _IXSSSafeFieldStorage(_IFieldStorage):
def get(self, field_name: str, default: Any = None, *, safe=True) -> Union[Any, None]:
if safe:
return _encode_html_entities(super().get(field_name, default))
_debug_warning_nonencoded_output()
return super().get(field_name, default)
def get_list(self, field_name: str, *, safe=True) -> List[Any]:
if safe:
return [_encode_html_entities(value) for value in super().get_list(field_name)]
_debug_warning_nonencoded_output()
return super().get_list(field_name)
def _debug_warning_nonencoded_output():
"""Warns about XSS risks."""
print(
"WARNING: Setting safe to False makes XSS vulnerabilities possible by "
"allowing access to raw untrusted values submitted by users. If this data is reflected "
"or shown within HTML without proper encoding it could enable Cross-Site Scripting."
)