mirror of
https://github.com/searxng/searxng.git
synced 2024-12-03 07:56:27 +00:00
237 lines
7.8 KiB
Python
237 lines
7.8 KiB
Python
# SPDX-License-Identifier: AGPL-3.0-or-later
|
|
"""Implementations for a favicon proxy"""
|
|
|
|
from __future__ import annotations
|
|
|
|
from typing import Callable
|
|
|
|
import importlib
|
|
import base64
|
|
import pathlib
|
|
import urllib.parse
|
|
|
|
import flask
|
|
from httpx import HTTPError
|
|
import msgspec
|
|
|
|
from searx import get_setting
|
|
|
|
from searx.webutils import new_hmac, is_hmac_of
|
|
from searx.exceptions import SearxEngineResponseException
|
|
|
|
from .resolvers import DEFAULT_RESOLVER_MAP
|
|
from . import cache
|
|
|
|
DEFAULT_FAVICON_URL = {}
|
|
CFG: FaviconProxyConfig = None # type: ignore
|
|
|
|
|
|
def init(cfg: FaviconProxyConfig):
|
|
global CFG # pylint: disable=global-statement
|
|
CFG = cfg
|
|
|
|
|
|
def _initial_resolver_map():
|
|
d = {}
|
|
name: str = get_setting("search.favicon_resolver", None) # type: ignore
|
|
if name:
|
|
func = DEFAULT_RESOLVER_MAP.get(name)
|
|
if func:
|
|
d = {name: f"searx.favicons.resolvers.{func.__name__}"}
|
|
return d
|
|
|
|
|
|
class FaviconProxyConfig(msgspec.Struct):
|
|
"""Configuration of the favicon proxy."""
|
|
|
|
max_age: int = 60 * 60 * 24 * 7 # seven days
|
|
"""HTTP header Cache-Control_ ``max-age``
|
|
|
|
.. _Cache-Control: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control
|
|
"""
|
|
|
|
secret_key: str = get_setting("server.secret_key") # type: ignore
|
|
"""By default, the value from :ref:`server.secret_key <settings server>`
|
|
setting is used."""
|
|
|
|
resolver_timeout: int = get_setting("outgoing.request_timeout") # type: ignore
|
|
"""Timeout which the resolvers should not exceed, is usually passed to the
|
|
outgoing request of the resolver. By default, the value from
|
|
:ref:`outgoing.request_timeout <settings outgoing>` setting is used."""
|
|
|
|
resolver_map: dict[str, str] = msgspec.field(default_factory=_initial_resolver_map)
|
|
"""The resolver_map is a key / value dictionary where the key is the name of
|
|
the resolver and the value is the fully qualifying name (fqn) of resolver's
|
|
function (the callable). The resolvers from the python module
|
|
:py:obj:`searx.favicons.resolver` are available by default."""
|
|
|
|
def get_resolver(self, name: str) -> Callable | None:
|
|
"""Returns the callable object (function) of the resolver with the
|
|
``name``. If no resolver is registered for the ``name``, ``None`` is
|
|
returned.
|
|
"""
|
|
fqn = self.resolver_map.get(name)
|
|
if fqn is None:
|
|
return None
|
|
mod_name, _, func_name = fqn.rpartition('.')
|
|
mod = importlib.import_module(mod_name)
|
|
func = getattr(mod, func_name)
|
|
if func is None:
|
|
raise ValueError(f"resolver {fqn} is not implemented")
|
|
return func
|
|
|
|
favicon_path: str = get_setting("ui.static_path") + "/themes/{theme}/img/empty_favicon.svg" # type: ignore
|
|
favicon_mime_type: str = "image/svg+xml"
|
|
|
|
def favicon(self, **replacements):
|
|
"""Returns pathname and mimetype of the default favicon."""
|
|
return (
|
|
pathlib.Path(self.favicon_path.format(**replacements)),
|
|
self.favicon_mime_type,
|
|
)
|
|
|
|
def favicon_data_url(self, **replacements):
|
|
"""Returns data image URL of the default favicon."""
|
|
|
|
cache_key = ", ".join(f"{x}:{replacements[x]}" for x in sorted(list(replacements.keys()), key=str))
|
|
data_url = DEFAULT_FAVICON_URL.get(cache_key)
|
|
if data_url is not None:
|
|
return data_url
|
|
|
|
fav, mimetype = CFG.favicon(**replacements)
|
|
# hint: encoding utf-8 limits favicons to be a SVG image
|
|
with fav.open("r", encoding="utf-8") as f:
|
|
data_url = f.read()
|
|
|
|
data_url = urllib.parse.quote(data_url)
|
|
data_url = f"data:{mimetype};utf8,{data_url}"
|
|
DEFAULT_FAVICON_URL[cache_key] = data_url
|
|
return data_url
|
|
|
|
|
|
def favicon_proxy():
|
|
"""REST API of SearXNG's favicon proxy service
|
|
|
|
::
|
|
|
|
/favicon_proxy?authority=<...>&h=<...>
|
|
|
|
``authority``:
|
|
Domain name :rfc:`3986` / see :py:obj:`favicon_url`
|
|
|
|
``h``:
|
|
HMAC :rfc:`2104`, build up from the :ref:`server.secret_key <settings
|
|
server>` setting.
|
|
|
|
"""
|
|
authority = flask.request.args.get('authority')
|
|
|
|
# malformed request or RFC 3986 authority
|
|
if not authority or "/" in authority:
|
|
return '', 400
|
|
|
|
# malformed request / does not have authorisation
|
|
if not is_hmac_of(
|
|
CFG.secret_key,
|
|
authority.encode(),
|
|
flask.request.args.get('h', ''),
|
|
):
|
|
return '', 400
|
|
|
|
resolver = flask.request.preferences.get_value('favicon_resolver') # type: ignore
|
|
# if resolver is empty or not valid, just return HTTP 400.
|
|
if not resolver or resolver not in CFG.resolver_map.keys():
|
|
return "", 400
|
|
|
|
data, mime = search_favicon(resolver, authority)
|
|
|
|
if data is not None and mime is not None:
|
|
resp = flask.Response(data, mimetype=mime) # type: ignore
|
|
resp.headers['Cache-Control'] = f"max-age={CFG.max_age}"
|
|
return resp
|
|
|
|
# return default favicon from static path
|
|
theme = flask.request.preferences.get_value("theme") # type: ignore
|
|
fav, mimetype = CFG.favicon(theme=theme)
|
|
return flask.send_from_directory(fav.parent, fav.name, mimetype=mimetype)
|
|
|
|
|
|
def search_favicon(resolver: str, authority: str) -> tuple[None | bytes, None | str]:
|
|
"""Sends the request to the favicon resolver and returns a tuple for the
|
|
favicon. The tuple consists of ``(data, mime)``, if the resolver has not
|
|
determined a favicon, both values are ``None``.
|
|
|
|
``data``:
|
|
Binary data of the favicon.
|
|
|
|
``mime``:
|
|
Mime type of the favicon.
|
|
|
|
"""
|
|
|
|
data, mime = (None, None)
|
|
|
|
func = CFG.get_resolver(resolver)
|
|
if func is None:
|
|
return data, mime
|
|
|
|
# to avoid superfluous requests to the resolver, first look in the cache
|
|
data_mime = cache.CACHE(resolver, authority)
|
|
if data_mime is not None:
|
|
return data_mime
|
|
|
|
try:
|
|
data, mime = func(authority, timeout=CFG.resolver_timeout)
|
|
if data is None or mime is None:
|
|
data, mime = (None, None)
|
|
|
|
except (HTTPError, SearxEngineResponseException):
|
|
pass
|
|
|
|
cache.CACHE.set(resolver, authority, mime, data)
|
|
return data, mime
|
|
|
|
|
|
def favicon_url(authority: str) -> str:
|
|
"""Function to generate the image URL used for favicons in SearXNG's result
|
|
lists. The ``authority`` argument (aka netloc / :rfc:`3986`) is usually a
|
|
(sub-) domain name. This function is used in the HTML (jinja) templates.
|
|
|
|
.. code:: html
|
|
|
|
<div class="favicon">
|
|
<img src="{{ favicon_url(result.parsed_url.netloc) }}">
|
|
</div>
|
|
|
|
The returned URL is a route to :py:obj:`favicon_proxy` REST API.
|
|
|
|
If the favicon is already in the cache, the returned URL is a `data URL`_
|
|
(something like ``data:image/png;base64,...``). By generating a data url from
|
|
the :py:obj:`.cache.FaviconCache`, additional HTTP roundtripps via the
|
|
:py:obj:`favicon_proxy` are saved. However, it must also be borne in mind
|
|
that data urls are not cached in the client (web browser).
|
|
|
|
.. _data URL: https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/Data_URLs
|
|
|
|
"""
|
|
|
|
resolver = flask.request.preferences.get_value('favicon_resolver') # type: ignore
|
|
# if resolver is empty or not valid, just return nothing.
|
|
if not resolver or resolver not in CFG.resolver_map.keys():
|
|
return ""
|
|
|
|
data_mime = cache.CACHE(resolver, authority)
|
|
|
|
if data_mime == (None, None):
|
|
# we have already checked, the resolver does not have a favicon
|
|
theme = flask.request.preferences.get_value("theme") # type: ignore
|
|
return CFG.favicon_data_url(theme=theme)
|
|
|
|
if data_mime is not None:
|
|
data, mime = data_mime
|
|
return f"data:{mime};base64,{str(base64.b64encode(data), 'utf-8')}" # type: ignore
|
|
|
|
h = new_hmac(CFG.secret_key, authority.encode())
|
|
proxy_url = flask.url_for('favicon_proxy')
|
|
query = urllib.parse.urlencode({"authority": authority, "h": h})
|
|
return f"{proxy_url}?{query}"
|