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CSS sanitization and serialisation in a good place

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This commit is contained in:
Tyler Hallada 2020-04-25 18:59:18 -04:00
parent e4316f1a6f
commit caca121bef
5 changed files with 81 additions and 42 deletions
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1
src/config/default.rs
View File

@ -13,6 +13,7 @@ lazy_static! {
allowed_protocols: HashMap::new(),
allowed_css_at_rules: HashSet::new(),
allowed_css_properties: HashSet::new(),
allow_css_comments: false,
remove_contents_when_unwrapped: hashset! {
local_name!("iframe"),
local_name!("noembed"),

32
src/css_parser.rs
View File

@ -35,6 +35,7 @@ pub struct CssDeclaration {
pub value: String,
}
#[derive(Debug)]
struct CssAtRulePrelude {
name: String,
prelude: String,
@ -145,7 +146,6 @@ impl<'i> QualifiedRuleParser<'i> for CssParser {
prelude.push_str("/**/");
}
previous_token = token_type;
dbg!(&token);
token.to_css(&mut prelude).unwrap();
// TODO: do I need to handle parse_nested_block here?
}
@ -206,7 +206,6 @@ impl<'i> DeclarationParser<'i> for CssDeclarationParser {
name: CowRcStr<'i>,
input: &mut Parser<'i, 't>,
) -> Result<Self::Declaration, ParseError<'i, CssError>> {
dbg!(&name);
// let start = input.position();
let mut value = String::new();
let mut previous_token = TokenSerializationType::nothing();
@ -216,26 +215,45 @@ impl<'i> DeclarationParser<'i> for CssDeclarationParser {
value.push_str("/**/");
}
previous_token = token_type;
dbg!(&token);
token.to_css(&mut value).unwrap();
// TODO: do I need to handle parse_nested_block here?
}
// input.next_including_whitespace_and_comments()?;
// let value = input.slice_from(start);
dbg!(&value);
Ok(vec![CssDeclaration {
property: name.to_string(),
value: value.to_string(),
value,
}])
}
}
impl<'i> AtRuleParser<'i> for CssDeclarationParser {
type PreludeBlock = ();
type PreludeNoBlock = ();
type PreludeBlock = CssAtRulePrelude;
type PreludeNoBlock = CssAtRulePrelude;
type AtRule = Vec<CssDeclaration>;
type Error = CssError;
fn parse_prelude<'t>(
&mut self,
name: CowRcStr<'i>,
input: &mut Parser<'i, 't>,
) -> Result<AtRuleType<Self::PreludeNoBlock, Self::PreludeBlock>, CssParseError<'i>> {
let mut prelude = String::new();
Ok(AtRuleType::WithBlock(CssAtRulePrelude {
name: name.to_string(),
prelude,
}))
}
fn parse_block<'t>(
&mut self,
prelude: Self::PreludeBlock,
_location: SourceLocation,
input: &mut Parser<'i, 't>,
) -> Result<Self::AtRule, CssParseError<'i>> {
Ok(vec![])
}
}
pub fn parse_declarations<'i>(

44
src/css_parser_2.rs → src/css_token_parser.rs
View File

@ -1,15 +1,24 @@
// Note: not using this parser. It would be easier to preserve whitespace in the css strings using
// this parser but it requires me to do too much of what cssparser is already doing for me
// (distinguishing between an at-rule `Ident` vs. a style rule `Ident`).
use std::borrow::Borrow;
use std::cell::Ref;
use cssparser::{ParseError, Parser, ParserInput, ToCss, Token, TokenSerializationType};
use html5ever::tendril::StrTendril;
use crate::css_property::CssProperty;
use crate::sanitizer::SanitizerConfig;
pub fn write_to(
mut previous_token: TokenSerializationType,
input: &mut Parser,
string: &mut String,
preserve_comments: bool,
config: &SanitizerConfig,
skipping_property: bool,
skipping_at_rule: bool,
) {
while let Ok(token) = if preserve_comments {
while let Ok(token) = if config.allow_css_comments {
input
.next_including_whitespace_and_comments()
.map(|t| t.clone())
@ -17,10 +26,24 @@ pub fn write_to(
input.next_including_whitespace().map(|t| t.clone())
} {
let token_type = token.serialization_type();
if !preserve_comments && previous_token.needs_separator_when_before(token_type) {
let mut skipping_property = skipping_property;
let mut skipping_at_rule = skipping_at_rule;
if !config.allow_css_comments && previous_token.needs_separator_when_before(token_type) {
string.push_str("/**/")
}
previous_token = token_type;
match &token {
Token::Ident(property) => {
let property_str: &str = property.borrow();
if !config
.allowed_css_properties
.contains(&CssProperty::from(property_str))
{
skipping_property = true;
}
}
_ => {}
}
dbg!(&token);
token.to_css(string).unwrap();
let closing_token = match token {
@ -31,7 +54,14 @@ pub fn write_to(
};
if let Some(closing_token) = closing_token {
let result: Result<_, ParseError<()>> = input.parse_nested_block(|input| {
write_to(previous_token, input, string, preserve_comments);
write_to(
previous_token,
input,
string,
config,
skipping_property,
skipping_at_rule,
);
Ok(())
});
result.unwrap();
@ -40,13 +70,15 @@ pub fn write_to(
}
}
pub fn parse_and_serialize(input: Ref<StrTendril>, output: &mut String, preserve_comments: bool) {
pub fn parse_and_serialize(input: Ref<StrTendril>, output: &mut String, config: &SanitizerConfig) {
let mut parser_input = ParserInput::new(&input);
let parser = &mut Parser::new(&mut parser_input);
write_to(
TokenSerializationType::nothing(),
parser,
output,
preserve_comments,
config,
false,
false,
);
}

1
src/main.rs
View File

@ -24,7 +24,6 @@ mod css_at_rule {
mod arena_dom;
mod config;
mod css_parser;
mod css_parser_2;
mod sanitizer;
use arena_dom::{create_element, Arena, NodeData, Ref};

41
src/sanitizer.rs
View File

@ -9,8 +9,8 @@ use html5ever::{parse_document, parse_fragment, serialize, Attribute, LocalName,
use crate::arena_dom::{Arena, Node, NodeData, Ref, Sink};
use crate::css_at_rule::CssAtRule;
use crate::css_parser::{parse_css_style_attribute, parse_css_stylesheet, CssRule};
use crate::css_parser_2::parse_and_serialize;
use crate::css_property::CssProperty;
use crate::css_token_parser::parse_and_serialize;
pub struct Sanitizer<'arena> {
arena: typed_arena::Arena<Node<'arena>>,
@ -29,6 +29,7 @@ pub struct SanitizerConfig {
pub allowed_protocols: HashMap<LocalName, HashMap<LocalName, HashSet<Protocol<'static>>>>,
pub allowed_css_at_rules: HashSet<CssAtRule>,
pub allowed_css_properties: HashSet<CssProperty>,
pub allow_css_comments: bool,
pub remove_contents_when_unwrapped: HashSet<LocalName>,
}
@ -129,7 +130,7 @@ impl<'arena> Sanitizer<'arena> {
self.add_attributes(node);
self.sanitize_attribute_protocols(node);
self.sanitize_style_tag_css(node);
// self.sanitize_style_attribute_css(node);
self.sanitize_style_attribute_css(node);
// self.serialize_css_test(node);
for transformer in self.transformers.iter() {
@ -241,16 +242,11 @@ impl<'arena> Sanitizer<'arena> {
let attrs = &mut attrs.borrow_mut();
if let Some(protocols) = self.config.allowed_protocols.get(&name.local) {
dbg!(protocols);
dbg!(&attrs);
let mut i = 0;
while i != attrs.len() {
dbg!(&attrs[i].name.local);
if let Some(allowed_protocols) = protocols.get(&attrs[i].name.local) {
dbg!(allowed_protocols);
match Url::parse(&attrs[i].value) {
Ok(url) => {
dbg!(Protocol::Scheme(url.scheme()));
if !allowed_protocols.contains(&Protocol::Scheme(url.scheme())) {
attrs.remove(i);
} else {
@ -258,7 +254,6 @@ impl<'arena> Sanitizer<'arena> {
}
}
Err(ParseError::RelativeUrlWithoutBase) => {
dbg!("relative");
if !allowed_protocols.contains(&Protocol::Relative) {
attrs.remove(i);
} else {
@ -297,7 +292,6 @@ impl<'arena> Sanitizer<'arena> {
sanitized_css += " }";
}
CssRule::AtRule(at_rule) => {
dbg!(&at_rule);
if self
.config
.allowed_css_at_rules
@ -309,6 +303,8 @@ impl<'arena> Sanitizer<'arena> {
sanitized_css += "{";
sanitized_css += &self.serialize_sanitized_css_rules(block);
sanitized_css += " }";
} else {
sanitized_css += "; ";
}
}
}
@ -326,9 +322,7 @@ impl<'arena> Sanitizer<'arena> {
if let NodeData::Element { ref name, .. } = parent.data {
if name.local == local_name!("style") {
let rules = parse_css_stylesheet(&contents.borrow());
dbg!(&rules);
let sanitized_css = self.serialize_sanitized_css_rules(rules);
dbg!(&sanitized_css);
contents.replace(StrTendril::from(sanitized_css));
}
}
@ -342,7 +336,6 @@ impl<'arena> Sanitizer<'arena> {
if attr.name.local == local_name!("style") {
let css_str = &attr.value;
let declarations = parse_css_style_attribute(css_str);
dbg!(&declarations);
let mut sanitized_css = String::new();
for declaration in declarations.into_iter() {
let declaration_string = &declaration.to_string();
@ -356,7 +349,6 @@ impl<'arena> Sanitizer<'arena> {
}
}
let sanitized_css = sanitized_css.trim();
dbg!(&sanitized_css);
attr.value = StrTendril::from(sanitized_css);
}
}
@ -369,7 +361,7 @@ impl<'arena> Sanitizer<'arena> {
if let NodeData::Element { ref name, .. } = parent.data {
if name.local == local_name!("style") {
let mut serialized_css = String::new();
parse_and_serialize(contents.borrow(), &mut serialized_css, true);
parse_and_serialize(contents.borrow(), &mut serialized_css, self.config);
}
}
}
@ -415,6 +407,7 @@ mod test {
allowed_protocols: HashMap::new(),
allowed_css_at_rules: HashSet::new(),
allowed_css_properties: HashSet::new(),
allow_css_comments: false,
remove_contents_when_unwrapped: HashSet::new(),
};
}
@ -728,31 +721,27 @@ mod test {
}
#[test]
fn sanitize_style_tag_css() {
fn sanitize_style_attribute_css() {
let mut sanitize_css_config = EMPTY_CONFIG.clone();
sanitize_css_config
.allowed_elements
.extend(vec![local_name!("html"), local_name!("style")]);
.extend(vec![local_name!("html"), local_name!("div")]);
sanitize_css_config
.allowed_attributes
.extend(vec![local_name!("style")]);
sanitize_css_config
.allowed_css_properties
.extend(vec![css_property!("margin"), css_property!("color")]);
sanitize_css_config
.allowed_css_at_rules
.extend(vec![css_at_rule!("charset")]);
let sanitizer = Sanitizer::new(&sanitize_css_config, vec![]);
let mut mock_data = MockRead::new(
"<style>@charset \"UTF-8\";\
div { margin: 10px; padding: 10px; color: red; }\
@media print { div { margin: 50px; } }</style>",
);
let mut mock_data =
MockRead::new("<div style=\"margin: 10px; padding: 10px; color: red;\"></div>");
let mut output = vec![];
sanitizer
.sanitize_fragment(&mut mock_data, &mut output)
.unwrap();
assert_eq!(
str::from_utf8(&output).unwrap(),
"<html><style>@charset \"UTF-8\";\
div { margin: 10px; color: red; }</style></html>"
"<html><div style=\"margin: 10px; color: red;\"></div></html>"
);
}
}