2024-12-04 13:35:57 +05:00

101 lines
3.7 KiB
Python

from __future__ import annotations
import collections.abc as cabc
import typing as t
from .structures import CallbackDict
def csp_property(key: str) -> t.Any:
"""Return a new property object for a content security policy header.
Useful if you want to add support for a csp extension in a
subclass.
"""
return property(
lambda x: x._get_value(key),
lambda x, v: x._set_value(key, v),
lambda x: x._del_value(key),
f"accessor for {key!r}",
)
class ContentSecurityPolicy(CallbackDict[str, str]):
"""Subclass of a dict that stores values for a Content Security Policy
header. It has accessors for all the level 3 policies.
Because the csp directives in the HTTP header use dashes the
python descriptors use underscores for that.
To get a header of the :class:`ContentSecuirtyPolicy` object again
you can convert the object into a string or call the
:meth:`to_header` method. If you plan to subclass it and add your
own items have a look at the sourcecode for that class.
.. versionadded:: 1.0.0
Support for Content Security Policy headers was added.
"""
base_uri: str | None = csp_property("base-uri")
child_src: str | None = csp_property("child-src")
connect_src: str | None = csp_property("connect-src")
default_src: str | None = csp_property("default-src")
font_src: str | None = csp_property("font-src")
form_action: str | None = csp_property("form-action")
frame_ancestors: str | None = csp_property("frame-ancestors")
frame_src: str | None = csp_property("frame-src")
img_src: str | None = csp_property("img-src")
manifest_src: str | None = csp_property("manifest-src")
media_src: str | None = csp_property("media-src")
navigate_to: str | None = csp_property("navigate-to")
object_src: str | None = csp_property("object-src")
prefetch_src: str | None = csp_property("prefetch-src")
plugin_types: str | None = csp_property("plugin-types")
report_to: str | None = csp_property("report-to")
report_uri: str | None = csp_property("report-uri")
sandbox: str | None = csp_property("sandbox")
script_src: str | None = csp_property("script-src")
script_src_attr: str | None = csp_property("script-src-attr")
script_src_elem: str | None = csp_property("script-src-elem")
style_src: str | None = csp_property("style-src")
style_src_attr: str | None = csp_property("style-src-attr")
style_src_elem: str | None = csp_property("style-src-elem")
worker_src: str | None = csp_property("worker-src")
def __init__(
self,
values: cabc.Mapping[str, str] | cabc.Iterable[tuple[str, str]] | None = (),
on_update: cabc.Callable[[ContentSecurityPolicy], None] | None = None,
) -> None:
super().__init__(values, on_update)
self.provided = values is not None
def _get_value(self, key: str) -> str | None:
"""Used internally by the accessor properties."""
return self.get(key)
def _set_value(self, key: str, value: str | None) -> None:
"""Used internally by the accessor properties."""
if value is None:
self.pop(key, None)
else:
self[key] = value
def _del_value(self, key: str) -> None:
"""Used internally by the accessor properties."""
if key in self:
del self[key]
def to_header(self) -> str:
"""Convert the stored values into a cache control header."""
from ..http import dump_csp_header
return dump_csp_header(self)
def __str__(self) -> str:
return self.to_header()
def __repr__(self) -> str:
kv_str = " ".join(f"{k}={v!r}" for k, v in sorted(self.items()))
return f"<{type(self).__name__} {kv_str}>"