css_sanitizer/
lib.rs

1//! # css-sanitizer
2//!
3//! Policy-driven CSS sanitization on top of `lightningcss`.
4//!
5//! This crate exposes `lightningcss` and lets you sanitize parsed CSS AST nodes
6//! directly through [`CssSanitizationPolicy`]. There is no built-in safe preset:
7//! the safety properties come from the policy you implement.
8//!
9//! Default trait methods are fail-open and return
10//! [`NodeAction::Continue`]. A strict sanitizer must explicitly drop the rules,
11//! selectors, properties, and descriptors it does not want to keep.
12//!
13//! ## String API
14//!
15//! ```rust
16//! use css_sanitizer::{
17//!     clean_stylesheet_with_policy, CssSanitizationPolicy, NodeAction, PropertyContext,
18//!     RuleContext,
19//! };
20//! use css_sanitizer::lightningcss::rules::CssRule;
21//!
22//! struct StyleColorOnly;
23//!
24//! impl CssSanitizationPolicy for StyleColorOnly {
25//!     fn visit_rule(
26//!         &self,
27//!         rule: &mut CssRule<'_>,
28//!         _ctx: RuleContext,
29//!     ) -> NodeAction {
30//!         match rule {
31//!             CssRule::Style(_) => NodeAction::Continue,
32//!             _ => NodeAction::Drop,
33//!         }
34//!     }
35//!
36//!     fn visit_property(
37//!         &self,
38//!         property: &mut css_sanitizer::lightningcss::properties::Property<'_>,
39//!         _ctx: PropertyContext,
40//!     ) -> NodeAction {
41//!         if property.property_id().name() == "color" {
42//!             NodeAction::Continue
43//!         } else {
44//!             NodeAction::Drop
45//!         }
46//!     }
47//! }
48//!
49//! let safe = clean_stylesheet_with_policy(
50//!     "@import url('evil.css'); .card { color: red; position: fixed }",
51//!     &StyleColorOnly,
52//! );
53//!
54//! assert!(!safe.contains("@import"));
55//! assert!(safe.contains("color"));
56//! assert!(!safe.contains("position"));
57//! ```
58//!
59//! ## AST API
60//!
61//! ```rust
62//! use css_sanitizer::{
63//!     sanitize_stylesheet_ast, CssSanitizationPolicy, NodeAction, RuleContext,
64//! };
65//! use css_sanitizer::lightningcss::rules::CssRule;
66//! use css_sanitizer::lightningcss::stylesheet::{ParserOptions, StyleSheet};
67//!
68//! struct NoImports;
69//!
70//! impl CssSanitizationPolicy for NoImports {
71//!     fn visit_rule(
72//!         &self,
73//!         rule: &mut CssRule<'_>,
74//!         _ctx: RuleContext,
75//!     ) -> NodeAction {
76//!         if matches!(rule, CssRule::Import(_)) {
77//!             NodeAction::Drop
78//!         } else {
79//!             NodeAction::Continue
80//!         }
81//!     }
82//! }
83//!
84//! let mut stylesheet =
85//!     StyleSheet::parse("@import url('evil.css'); .card { color: blue }", ParserOptions::default())
86//!         .expect("stylesheet should parse");
87//!
88//! sanitize_stylesheet_ast(&mut stylesheet, &NoImports);
89//!
90//! let output = stylesheet
91//!     .to_css(Default::default())
92//!     .expect("stylesheet should serialize")
93//!     .code;
94//! assert!(!output.contains("@import"));
95//! assert!(output.contains(".card"));
96//! ```
97
98mod policy;
99mod sanitize;
100
101pub use lightningcss;
102pub use policy::{
103    CssSanitizationPolicy, DescriptorContext, NodeAction, PropertyContext, RuleContext,
104    SelectorContext,
105};
106pub use sanitize::{
107    clean_declaration_list_with_policy, clean_stylesheet_with_policy,
108    sanitize_declaration_block_ast, sanitize_stylesheet_ast,
109};
css_sanitizer/lib.rs

css_sanitizer/
lib.rs
