Passively capture, archive, and hoard your web browsing history, including the contents of the pages you visit, for later offline viewing, mirroring, and/or indexing. Your own personal private Wayback Machine that can also archive HTTP POST requests and responses, as well as most other HTTP-level data.
# Copyright (c) 2023-2024 Jan Malakhovski <oxij@oxij.org>
#
# This file is a part of `hoardy-web` project.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""Parsing and scrubbing of HTML data.
"""
import collections as _c
import dataclasses as _dc
import enum as _enum
import re as _re
import traceback as _traceback
import typing as _t
import urllib.parse as _up
import html5lib as _h5
import html5lib.filters.base as _h5fb
import html5lib.filters.whitespace as _h5ws
import html5lib.filters.optionaltags as _h5ot
import tinycss2 as _tcss
from kisstdlib.exceptions import *
from .wire import *
from .mime import *
from .util import map_optional, map_optionals, make_func_pipe
def is_data_url(url : str) -> bool:
return url.startswith("data:")
def is_script_url(url : str) -> bool:
return url.startswith("javascript:")
def is_page_url(url : str) -> bool:
return url.startswith("http:") or url.startswith("https:")
class LinkType(_enum.Enum):
JUMP = 0
ACTION = 1
REQ = 2
def get_void_url(link_type : LinkType) -> str:
if link_type == LinkType.REQ:
return "data:text/plain,%20"
else:
return "javascript:void(0)"
RefType = tuple[LinkType, list[str]] # tuple[LinkType, possible mime types]
URLRemapper = _t.Callable[[LinkType, list[str] | None, str], str | None] | None
HTML5Node = dict[str, _t.Any]
HTML5NN = tuple[str | None, str] # NN = namespaced name
HTML5NodeAttr = tuple[HTML5NN, HTML5NN] # tuple[namespaced token name, namespaced attribute name]
HTML5NodeAttrValues = _c.OrderedDict[HTML5NN, str]
CSSNode : _t.TypeAlias = _tcss.ast.Node
def debug_walker(walker : _t.Iterator[HTML5Node]) -> _t.Iterator[HTML5Node]:
for token in walker:
print(token)
yield token
htmlns = _h5.constants.namespaces["html"]
xlinkns = _h5.constants.namespaces["xlink"]
xmlns = _h5.constants.namespaces["xml"]
htmlns_a = (htmlns, "a")
htmlns_area = (htmlns, "area")
htmlns_audio = (htmlns, "audio")
htmlns_base = (htmlns, "base")
htmlns_blockquote = (htmlns, "blockquote")
htmlns_body = (htmlns, "body")
htmlns_button = (htmlns, "button")
htmlns_del = (htmlns, "del")
htmlns_embed = (htmlns, "embed")
htmlns_form = (htmlns, "form")
htmlns_frame = (htmlns, "frame")
htmlns_head = (htmlns, "head")
htmlns_html = (htmlns, "html")
htmlns_iframe = (htmlns, "iframe")
htmlns_img = (htmlns, "img")
htmlns_input = (htmlns, "input")
htmlns_ins = (htmlns, "ins")
htmlns_link = (htmlns, "link")
htmlns_meta= (htmlns, "meta")
htmlns_noscript = (htmlns, "noscript")
htmlns_object = (htmlns, "object")
htmlns_q = (htmlns, "q")
htmlns_script = (htmlns, "script")
htmlns_source = (htmlns, "source")
htmlns_style = (htmlns, "style")
htmlns_title = (htmlns, "title")
htmlns_track = (htmlns, "track")
htmlns_video = (htmlns, "video")
action_attr = (None, "action")
cite_attr = (None, "cite")
content_attr = (None, "content")
crossorigin_attr = (None, "crossorigin")
data_attr = (None, "data")
formaction_attr = (None, "formaction")
href_attr = (None, "href")
http_equiv_attr = (None, "http-equiv")
integrity_attr = (None, "integrity")
nonce_attr = (None, "nonce")
ping_attr = (None, "ping")
poster_attr = (None, "poster")
rel_attr = (None, "rel")
src_attr = (None, "src")
srcset_attr = (None, "srcset")
style_attr = (None, "style")
# HTML elements that must preserve whitespace
html_whitespace_preserve_tags = _h5ws.Filter.spacePreserveElements
# HTML elements that ignore whitespace completely (and so whitespeace can be added or removed arbitrarily)
html_whitespace_ignore_tags = frozenset(["html", "head", "frameset"])
def prettify_html(indent : int, relaxed : bool, walker : _t.Iterator[HTML5Node]) \
-> _t.Iterator[HTML5Node]:
"""HTML prettification html5lib.Filter that adds lots of indent.
"""
stack : list[str] = []
preserve : int = 0
current : int = 0
on_space : bool = True
newline : bool = True
def space_ok() -> bool:
if len(stack) == 0:
return True
tp = stack[-1]
if tp in html_whitespace_ignore_tags:
return True
return False
def emit_indent() -> _t.Generator[HTML5Node, None, bool]:
if on_space or relaxed or space_ok():
if newline:
chars = " " * (indent * current)
else:
chars = "\n" + " " * (indent * current)
yield {"type": "SpaceCharacters", "data": chars}
return current == 0
else:
return False
prev_token : HTML5Node | None = None
for token in walker:
typ = token["type"]
if typ == "Doctype":
yield token
on_space = False
newline = False
elif typ == "EmptyTag":
tn = token["name"]
#if tn == "input":
# breakpoint()
if preserve == 0:
yield from emit_indent()
yield token
on_space = False
newline = False
elif typ == "StartTag":
tn = token["name"]
stack.append(tn)
if preserve == 0:
yield from emit_indent()
current += 1
if (preserve != 0 or tn in html_whitespace_preserve_tags):
preserve += 1
yield token
on_space = False
newline = False
elif typ == "EndTag":
current -= 1
if preserve == 0:
yield from emit_indent()
else:
preserve -= 1
stack.pop()
yield token
on_space = False
newline = False
else:
if preserve == 0:
if typ == "SpaceCharacters":
# skip useless whitespace
on_space = True
continue
newline = yield from emit_indent()
yield token
if typ == "SpaceCharacters":
on_space = True
newline = token["data"][-1:] == "\n"
else:
on_space = False
newline = False
prev_token = token
def headers_to_meta_http_equiv(headers : Headers) -> _t.Iterator[HTML5Node]:
"""Produce `<meta http-equiv>` tags from given `HTTP` headers."""
def emit_http_eqiuv(typ : str, value : str) -> _t.Iterator[HTML5Node]:
attrs = _c.OrderedDict()
attrs[http_equiv_attr] = typ
attrs[content_attr] = value
yield {"type": "EmptyTag", "namespace": htmlns, "name": "meta", "data": attrs}
# `Content-Type` headers are handled by `html5lib` and
# `protocol_encoding` below, so we ignore them here.
# `Content-Security-Policy` can be specified multiple times.
for csph in get_headers(headers, "content-security-policy"):
yield from emit_http_eqiuv("content-security-policy", csph)
# These headers should be inlined verbatim.
for name, value in headers:
if name.lower() in ["x-ua-compatible", "default-style", "refresh"]:
yield from emit_http_eqiuv(name, value.decode("ascii"))
# `Link` can be specified multiple times.
for lh in get_headers(headers, "link"):
yield from emit_http_eqiuv("link", lh)
class RemapType(_enum.Enum):
ID = 0
VOID = 1
OPEN = 2
CLOSED = 3
FALLBACK = 4
@_dc.dataclass
class ScrubbingOptions:
jumps : RemapType = _dc.field(default=RemapType.OPEN)
actions : RemapType = _dc.field(default=RemapType.FALLBACK)
reqs : RemapType = _dc.field(default=RemapType.FALLBACK)
unknown : bool = _dc.field(default=True)
styles : bool = _dc.field(default=True)
scripts : bool = _dc.field(default=False)
iepragmas : bool = _dc.field(default=False)
iframes : bool = _dc.field(default=True)
prefetches : bool = _dc.field(default=False)
tracking : bool = _dc.field(default=False)
navigations : bool = _dc.field(default=False)
interpret_noscript : bool = _dc.field(default=True)
verbose : bool = _dc.field(default=False)
whitespace : bool = _dc.field(default=False)
optional_tags : bool = _dc.field(default=True)
indent : bool = _dc.field(default=False)
indent_step : int = _dc.field(default=2)
debug : bool = _dc.field(default=False)
ScrubbingReferenceOptions = ["jumps", "actions", "reqs"]
ScrubbingDynamicOpts = ["styles", "scripts", "iepragmas", "iframes", "prefetches", "tracking", "navigations"]
class CSSScrubbingError(Failure): pass
Scrubbers = tuple[
_t.Callable[[str, URLRemapper, Headers, _t.Iterator[HTML5Node]], _t.Iterator[HTML5Node]],
_t.Callable[[str, URLRemapper, Headers, _t.Iterator[CSSNode]], list[CSSNode]],
]
ie_pragma_re = _re.compile(r"^\s*(\[if IE [^]]*\].*\[endif\]|\[if !IE\]><!|<!\[endif\])\s*$")
jump_ref : RefType = (LinkType.JUMP, page_mime)
action_ref : RefType = (LinkType.ACTION, page_mime)
attr_ref_type : dict[HTML5NodeAttr, RefType]
attr_ref_type = {
(htmlns_a, href_attr): jump_ref,
(htmlns_area, href_attr): jump_ref,
#(htmlns_base, href_attr): handled_separately,
(htmlns_blockquote, cite_attr): jump_ref,
(htmlns_del, cite_attr): jump_ref,
(htmlns_ins, cite_attr): jump_ref,
#(htmlns_link, href_attr): handled_separately,
(htmlns_object, data_attr): jump_ref,
(htmlns_q, cite_attr): jump_ref,
(htmlns_a, ping_attr): action_ref,
(htmlns_area, ping_attr): action_ref,
(htmlns_button, formaction_attr): action_ref,
(htmlns_form, action_attr): action_ref,
(htmlns_input, formaction_attr): action_ref,
(htmlns_audio, src_attr): (LinkType.REQ, audio_mime + audio_video_mime),
(htmlns_embed, src_attr): (LinkType.REQ, ["application/octet-stream"]),
(htmlns_frame, src_attr): (LinkType.REQ, page_mime),
(htmlns_iframe, src_attr): (LinkType.REQ, page_mime),
(htmlns_img, src_attr): (LinkType.REQ, image_mime),
#(htmlns_img, srcset_attr): handled_separately,
(htmlns_input, src_attr): (LinkType.REQ, image_mime),
(htmlns_script, src_attr): (LinkType.REQ, script_mime),
(htmlns_source, src_attr): (LinkType.REQ, media_mime),
(htmlns_track, src_attr): (LinkType.REQ, track_mime),
(htmlns_video, poster_attr): (LinkType.REQ, image_mime),
(htmlns_video, src_attr): (LinkType.REQ, video_mime + audio_video_mime),
}
prefetch_link_rels = frozenset([
"dns-prefetch", "preconnect", "prefetch", "prerender", "preload", "modulepreload",
])
stylesheet_link_rels = frozenset([
"stylesheet",
"ie-optimized-stylesheet-desk", "ie-optimized-onevent-stylesheet",
"kinetic-stylesheet",
])
icon_link_rels = frozenset([
"icon", "shortcut",
"apple-touch-icon", "apple-touch-startup-image", "apple-touch-icon-precomposed",
"fluid-icon", "mask-icon", "rich-pin-icon",
])
link_rel_ref_type : dict[str, RefType]
link_rel_ref_type = {}
for e in stylesheet_link_rels:
link_rel_ref_type[e] = (LinkType.REQ, stylesheet_mime)
for e in icon_link_rels:
link_rel_ref_type[e] = (LinkType.REQ, image_mime)
tracking_node_attrs = frozenset([
(htmlns_a, ping_attr),
(htmlns_area, ping_attr),
])
cors_node_attrs = frozenset([
(htmlns_audio, crossorigin_attr),
(htmlns_img, crossorigin_attr),
(htmlns_link, crossorigin_attr),
(htmlns_script, crossorigin_attr),
(htmlns_video, crossorigin_attr),
])
sri_node_attrs = frozenset([
(htmlns_link, integrity_attr),
(htmlns_script, integrity_attr),
(htmlns_style, integrity_attr),
(htmlns_script, nonce_attr),
(htmlns_style, nonce_attr),
])
def make_scrubbers(opts : ScrubbingOptions) -> Scrubbers:
attr_blacklist : set[HTML5NodeAttr] = set()
if not opts.tracking:
attr_blacklist.update(tracking_node_attrs)
attr_blacklist.update(cors_node_attrs)
attr_blacklist.update(sri_node_attrs)
link_rel_blacklist : set[str] = set()
if not opts.styles:
link_rel_blacklist.update(stylesheet_link_rels)
if not opts.prefetches:
link_rel_blacklist.update(prefetch_link_rels)
jumps = opts.jumps
actions = opts.actions
reqs = opts.reqs
yes_styles = opts.styles
not_styles = not yes_styles
yes_scripts = opts.scripts
not_scripts = not yes_scripts
not_iepragmas = not opts.iepragmas
not_iframes = not opts.iframes
yes_navigations = opts.navigations
yes_interpret_noscript = opts.interpret_noscript
yes_verbose = opts.verbose
not_verbose = not yes_verbose
not_whitespace = not opts.whitespace
yes_indent = opts.indent
indent_step = opts.indent_step
def remap_link_maybe(base_url : str,
link_type : LinkType,
fallbacks : list[str],
remap_url : URLRemapper,
url : str) -> str | None:
try:
url = _up.urljoin(base_url, url)
except ValueError:
return None
if is_data_url(url):
return url
if is_script_url(url) and not_scripts:
return None
rt : RemapType
if link_type == LinkType.JUMP:
rt = jumps
elif link_type == LinkType.ACTION:
rt = actions
else:
rt = reqs
if rt == RemapType.ID:
return url
elif rt == RemapType.VOID:
return None
rurl : str | None = None
if remap_url is not None:
rurl = remap_url(link_type, None if rt != RemapType.FALLBACK else fallbacks, url)
if rurl is not None:
return rurl
elif rt == RemapType.OPEN:
return url
else: # rt == RemapType.CLOSED or rt == RemapType.FALLBACK
return None
def remap_link_or_void(base_url : str,
link_type : LinkType,
fallbacks : list[str],
remap_url : URLRemapper,
url : str) -> str:
res = remap_link_maybe(base_url, link_type, fallbacks, remap_url, url)
if res is None:
return get_void_url(link_type)
return res
def scrub_css(base_url : str,
remap_url : URLRemapper,
nodes : _t.Iterator[CSSNode],
current : int | None = None,
errors : bool = False) -> list[CSSNode]:
if not_styles:
if not_verbose:
node = _tcss.ast.Comment(0, 0, f" hoardy-web censored out CSS data from here ")
return [node]
else:
return []
res = []
newline : bool = True
def emit_indent() -> None:
if current is not None:
if newline:
chars = " " * (indent_step * current)
else:
chars = "\n" + " " * (indent_step * current)
res.append(_tcss.ast.WhitespaceToken(0, 0, chars))
def at_import_prelude(nodes : _t.Iterator[CSSNode]) -> _t.Iterator[CSSNode]:
# map `@import "url.css" rest` -> `@import url("url.css") rest`
done = False
for node in nodes:
if done:
yield node
continue
if isinstance(node, _tcss.ast.StringToken):
node = _tcss.ast.FunctionBlock(node.source_line, node.source_column, "url", [node])
done = True
elif isinstance(node, (_tcss.ast.URLToken, _tcss.ast.FunctionBlock)):
done = True
yield node
# walk the AST tree recursively
for node in nodes:
if isinstance(node, (_tcss.ast.QualifiedRule, _tcss.ast.AtRule)):
emit_indent()
if isinstance(node, _tcss.ast.AtRule) and node.lower_at_keyword == "import":
prelude = at_import_prelude(node.prelude)
else:
prelude = node.prelude
node.prelude = scrub_css(base_url, remap_url, prelude)
if node.content is not None:
if current is not None:
try:
content = scrub_css(base_url, remap_url, _tcss.parse_blocks_contents(node.content), current + 1, True)
except CSSScrubbingError:
# it does not parse, scrub the tokens instead
content = scrub_css(base_url, remap_url, node.content)
node.content = \
[_tcss.ast.WhitespaceToken(0, 0, "\n")] + \
content + \
[_tcss.ast.WhitespaceToken(0, 0, "\n" + " " * (indent_step * current))]
del content
else:
# NB: no need to parse with `_tcss.parse_blocks_contents` in this case
node.content = scrub_css(base_url, remap_url, node.content)
elif isinstance(node, _tcss.ast.Declaration):
emit_indent()
node.value = scrub_css(base_url, remap_url, node.value)
elif isinstance(node, _tcss.ast.URLToken):
# remap the URL
url = remap_link_or_void(base_url, LinkType.REQ, css_url_mime, remap_url, node.value)
rep = f"url({_tcss.serializer.serialize_url(url)})"
node.value = url
node.representation = rep
elif isinstance(node, _tcss.ast.FunctionBlock):
if node.lower_name == "url":
# technically, this is a bug in the CSS we are processing, but browsers work around this, so do we
url = remap_link_or_void(base_url, LinkType.REQ, css_url_mime, remap_url, "".join([n.value for n in node.arguments if n.type == "string"]))
rep = f"url({_tcss.serializer.serialize_url(url)})"
res.append(_tcss.ast.URLToken(node.source_line, node.source_column, url, rep))
continue
node.arguments = scrub_css(base_url, remap_url, node.arguments)
elif isinstance(node, (_tcss.ast.ParenthesesBlock, _tcss.ast.SquareBracketsBlock, _tcss.ast.CurlyBracketsBlock)):
node.content = scrub_css(base_url, remap_url, node.content)
elif isinstance(node, _tcss.ast.Comment):
emit_indent()
elif isinstance(node, _tcss.ast.ParseError):
if errors:
raise CSSScrubbingError("tinycss2.ast.ParseError: %s: %s", node.kind, node.message)
# replace errors with comments explaining what failed to parse
emit_indent()
node = _tcss.ast.Comment(node.source_line, node.source_column,
f" hoardy-web CSS parsing error: {node.kind}: {node.message} ")
elif isinstance(node, _tcss.ast.WhitespaceToken):
if not_whitespace or current is not None:
# minimize away
res.append(_tcss.ast.WhitespaceToken(node.source_line, node.source_column, " "))
newline = False
continue
res.append(node)
newline = node.value.endswith("\n")
continue
res.append(node)
newline = False
return res
def goes_before_inlines(nn : HTML5NN, attrs : HTML5NodeAttrValues) -> bool:
"""Should this `<html><head>` tag go before the ones produced by `headers_to_meta_http_equiv`?"""
if nn == htmlns_base or nn == htmlns_title:
return True
elif nn == htmlns_meta:
if (None, "charset") in attrs:
return True
he = attrs.get(http_equiv_attr, None)
if he is not None and he.lower() == "content-type":
return True
return False
def link_rels_of(rels : str) -> list[str]:
rparts = map(lambda x: x.lower(), word_re.findall(rels))
return [r for r in rparts if r not in link_rel_blacklist]
def rel_ref_type_of(link_rels : list[str]) -> RefType:
slink_type = None
cts = []
for rel in link_rels:
link_type_, cts_ = link_rel_ref_type.get(rel, jump_ref)
if slink_type is None or link_type_ == LinkType.REQ:
slink_type = link_type_
cts += [e for e in cts_ if e not in cts]
link_type = slink_type if slink_type is not None else LinkType.JUMP
return link_type, cts
def scrub_html(orig_base_url : str,
remap_url : URLRemapper,
headers : Headers,
walker : _t.Iterator[HTML5Node]) -> _t.Iterator[HTML5Node]:
censor_lvl : int = 0
stack : list[HTML5NN] = []
assemble : HTML5Node | None
assemble = None
assemble_contents : list[str] = []
# `inline_headers` handling
inline_headers_undone = True
# `<base>` tag handling
base_url = orig_base_url
base_url_unset = True
def emit_censored_comment(what : str) -> _t.Iterator[HTML5Node]:
yield {"type": "Comment", "data": f" hoardy-web censored out {what.replace('-->', '-- >')} from here "}
def emit_censored_token(typ : str, token : HTML5Node) -> _t.Iterator[HTML5Node]:
if not_verbose: return
res = [typ]
tn = token.get("name", None)
if tn is not None:
res.append(tn)
if tn == "link":
rels = token.get("data", {}).get(rel_attr, None)
if rels is not None:
res.append(rels)
yield from emit_censored_comment(" ".join(res))
def emit_censored_other(what : str) -> _t.Iterator[HTML5Node]:
if not_verbose: return
yield from emit_censored_comment(what)
backlog : list[HTML5Node] = []
witer = iter(walker)
while True:
if len(backlog) > 0:
token = backlog.pop(0)
else:
try:
token = next(witer)
except StopIteration:
break
typ = token["type"]
if assemble is not None and (typ == "Characters" or typ == "SpaceCharacters"):
assemble_contents.append(token["data"])
continue
elif not_iepragmas and typ == "Comment" and ie_pragma_re.match(token["data"]):
yield from emit_censored_other("a comment with an IE pragma")
continue
in_head = stack == [htmlns_html, htmlns_head]
censor = censor_lvl != 0
if typ == "StartTag" or typ == "EmptyTag":
nn = (token["namespace"], token["name"])
attrs : HTML5NodeAttrValues = token["data"]
if not_scripts and yes_interpret_noscript and nn == htmlns_noscript:
# ignore this
yield from emit_censored_token(typ, token)
continue
# Handle HTTP header inlining.
# Put them after `<base>`, `<title>`, and charset-controlling `<meta>` headers.
if inline_headers_undone and \
not goes_before_inlines(nn, attrs) and \
in_head:
# inline them before this token
backlog = list(headers_to_meta_http_equiv(headers)) + [token] + backlog
inline_headers_undone = False
continue
# handle <base ...> tag
if base_url_unset and \
nn == htmlns_base and \
in_head:
href = map_optional(lambda x: x.strip(), attrs.get(href_attr, None))
if href is not None:
# add root slash to the URL if it's missing one
purl = _up.urlsplit(href)
if purl.netloc != "" and purl.path == "":
href = _up.urlunsplit((purl.scheme, purl.netloc, "/", purl.query, purl.fragment))
else:
href = purl.geturl()
href = _up.urljoin(orig_base_url, href)
#attrs[href_attr] = remap_url(href) # if no censorship
# set new base_url
base_url = href
# can only be set once
base_url_unset = False
# censor the original tag for simplicity
censor = True
if not censor and nn == htmlns_meta and http_equiv_attr in attrs:
kind = attrs[http_equiv_attr].lower()
content = attrs.get(content_attr, None)
# NB: These are always rebased onto `orig_base_url`, not the `base_url`.
if kind in ["content-type", "x-ua-compatible", "default-style"] and content is not None:
# simply accept these
pass
elif kind == "refresh" and content is not None:
if yes_navigations:
osecs, href = parse_refresh_header(content)
if osecs is not None:
if href is None:
attrs[content_attr] = str(osecs)
else:
href = remap_link_maybe(orig_base_url, LinkType.JUMP, page_mime, remap_url, href)
if href is not None and is_page_url(href):
attrs[content_attr] = str(osecs) + ";url=" + href
else:
censor = True
else:
censor = True
else:
censor = True
elif kind == "link" and content is not None:
# replace this header with a sequence of `<link>` headers
nbacklog = []
for url, params in parse_link_header(content):
try:
url = _up.urljoin(orig_base_url, url)
except ValueError:
# the `url` is malformed
pass
else:
tattrs = _c.OrderedDict()
for k, v in params:
nk = (None, k)
# only the first value matters, href_attr is not allowed
if nk in tattrs or nk == href_attr:
continue
tattrs[nk] = v
tattrs[href_attr] = url
nbacklog.append({"type": "EmptyTag", "namespace": htmlns, "name": "link", "data": tattrs})
if len(nbacklog) > 0:
# reset
backlog = nbacklog + backlog
continue
else:
censor = True
else:
# censor all others
censor = True
# TODO XXX: also parse and remap `content-security-policy`
if not censor and \
(not_styles and nn == htmlns_style or \
not_scripts and nn == htmlns_script or \
not_iframes and nn == htmlns_iframe):
# censor these out quickly
censor = True
new_attrs : _c.OrderedDict[HTML5NN, str | None] = _c.OrderedDict()
if not censor and nn == htmlns_link:
# scrub `link` `rel` attributes
link_rels = link_rels_of(attrs.get(rel_attr, ""))
if len(link_rels) > 0:
# scrub `link` `href` attributes
href = map_optional(lambda x: x.strip(), attrs.get(href_attr, None))
if href is not None:
link_rels_set = set(link_rels)
if is_data_url(href) and not link_rels_set.isdisjoint(stylesheet_link_rels):
# handle stylsheets given as `data:` URLs.
# yes, this is actually allowed =/
try:
href_mime, href_params, href_data = parse_data_url(href)
href_mime = canonical_mime_of.get(href_mime, href_mime)
if href_mime not in stylesheet_mime:
raise ValueError("not a stylesheet")
href_protocol_encoding = get_parameter(href_params, "charset", "utf-8")
href_nodes, href_encoding = _tcss.parse_stylesheet_bytes(href_data, protocol_encoding=href_protocol_encoding)
href_charset = href_encoding.name
href_params = set_parameter(href_params, "charset", href_charset)
href = unparse_data_url(href_mime, href_params, _tcss.serialize(scrub_css(base_url, remap_url, href_nodes, None)).encode(href_charset))
except (ParseError, ValueError):
href = None
else:
link_type, cts = rel_ref_type_of(link_rels)
href = remap_link_maybe(base_url, link_type, cts, remap_url, href)
else:
href = None
new_attrs[rel_attr] = " ".join(link_rels)
new_attrs[href_attr] = href
if href is None:
# censor the whole tag in this case
censor = True
if not censor:
# scrub other attributes
for ann, value in attrs.items():
nnann = (nn, ann)
if nnann in attr_blacklist or \
not_scripts and ann[0] is None and ann[1].startswith("on"):
# censor out blacklisted attrs,
# censor out javascript on* attributes, e.g. `onclick`
new_attrs[ann] = None
elif ann == style_attr:
# scrub inline styles
if yes_styles:
new_attrs[ann] = _tcss.serialize(scrub_css(base_url, remap_url, _tcss.parse_blocks_contents(value), 0 if yes_indent else None))
elif yes_verbose:
new_attrs[ann] = "/* hoardy-web censored out a CSS data from here */"
else:
new_attrs[ann] = None
elif ann == srcset_attr:
# scrub `srcset` attributes
new_srcset = []
for url, cond in parse_srcset_attr(value):
href = remap_link_maybe(base_url, LinkType.REQ, image_mime, remap_url, url)
if href is not None:
new_srcset.append((href, cond))
new_attrs[ann] = unparse_srcset_attr(new_srcset) if len(new_srcset) > 0 else None
else:
# handle other attributes containing URLs
ref = attr_ref_type.get(nnann, None)
if ref is not None:
link_type, cts = ref
new_attrs[ann] = remap_link_maybe(base_url, link_type, cts, remap_url, value.strip())
# apply changes
for ann, ovalue in new_attrs.items():
if ovalue is not None:
attrs[ann] = ovalue
else:
try:
del attrs[ann]
except KeyError: pass
if typ == "StartTag":
stack.append(nn)
if censor:
censor_lvl += 1
if nn == htmlns_style or nn == htmlns_script:
# start assembling contents
assemble = token
continue
elif typ == "EndTag":
# stop handling <base ...> tag
if in_head:
# as a fallback, dump inlines here
if inline_headers_undone:
backlog = list(headers_to_meta_http_equiv(headers)) + [token] + backlog
inline_headers_undone = False
continue
base_url_unset = False
nn = (token["namespace"], token["name"])
if not_scripts and yes_interpret_noscript and nn == htmlns_noscript:
# ignore this
yield from emit_censored_token(typ, token)
continue
stack_len = len(stack)
if censor:
censor_lvl -= 1
stack.pop()
#print(stack)
# scrub tag contents
if assemble is not None:
if not censor:
assemble_nn = (assemble["namespace"], assemble["name"])
#assemble_attrs : _c.OrderedDict[HTML5NN, str] = assemble["data"]
adata = "".join(assemble_contents)
if assemble_nn == htmlns_style:
adata = _tcss.serialize(scrub_css(base_url, remap_url, _tcss.parse_stylesheet(adata), stack_len if not_whitespace else None))
# TODO: scrub_js goes here
if opt_whitespace_re.fullmatch(adata):
adata = ""
elif yes_indent:
adata = "\n" + " " * (2 * stack_len) + adata.strip() + "\n" + " " * (2 * (stack_len - 1))
elif not_whitespace:
adata = adata.strip()
yield assemble
yield {"type": "Characters", "data": adata}
else:
token = assemble
typ = "AssembledTag"
assemble = None
assemble_contents = []
if censor:
if typ != "SpaceCharacters":
yield from emit_censored_token(typ, token)
continue
yield token
stages : list[_h5fb.Filter]
stages = []
if not opts.whitespace:
stages.append(_h5ws.Filter)
if opts.debug:
stages.append(lambda x: prettify_html(opts.indent_step, True, x))
elif opts.indent:
stages.append(lambda x: prettify_html(opts.indent_step, False, x))
if not opts.optional_tags:
stages.append(_h5ot.Filter)
pipe = make_func_pipe(stages)
process_html = lambda base_url, remap_url, headers, walker: pipe(scrub_html(base_url, remap_url, headers, walker))
process_css = lambda base_url, remap_url, headers, nodes: scrub_css(base_url, remap_url, nodes, 0 if yes_indent else None)
return process_html, process_css
def scrub_css(scrubbers : Scrubbers,
base_url : str,
remap_url : URLRemapper,
headers : Headers,
body : str | bytes,
protocol_encoding : str | None) -> bytes:
if isinstance(body, bytes):
nodes, encoding = _tcss.parse_stylesheet_bytes(body, protocol_encoding=protocol_encoding)
charset = encoding.name
else:
nodes = _tcss.parse_stylesheet(body)
charset = "utf-8"
res = scrubbers[1](base_url, remap_url, headers, nodes)
return _tcss.serialize(res).encode(charset) # type: ignore
_html5treebuilder = _h5.treebuilders.getTreeBuilder("etree", fullTree=True)
_html5parser = _h5.html5parser.HTMLParser(_html5treebuilder)
_html5walker = _h5.treewalkers.getTreeWalker("etree")
_html5serializer = _h5.serializer.HTMLSerializer(strip_whitespace = False, omit_optional_tags = False)
def scrub_html(scrubbers : Scrubbers,
base_url : str,
remap_url : URLRemapper,
headers : Headers,
body : str | bytes,
protocol_encoding : str | None) -> bytes:
if isinstance(body, bytes):
dom = _html5parser.parse(body, likely_encoding=protocol_encoding)
charset = _html5parser.tokenizer.stream.charEncoding[0].name
else:
dom = _html5parser.parse(body)
charset = "utf-8"
walker = scrubbers[0](base_url, remap_url, headers, _html5walker(dom))
return _html5serializer.render(walker, charset) # type: ignore