refactor(sanitizer): extract shared sanitizer module and migrate from ammonia to lol_html

Cargo.lock

@@ -23,19 +23,6 @@ version = "0.2.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
 
-[[package]]
-name = "ammonia"
-version = "4.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "17e913097e1a2124b46746c980134e8c954bc17a6a59bb3fde96f088d126dde6"
-dependencies = [
- "cssparser",
- "html5ever",
- "maplit",
- "tendril",
- "url",
-]
-
 [[package]]
 name = "android_system_properties"
 version = "0.1.5"
@@ -721,14 +708,14 @@ dependencies = [
 
 [[package]]
 name = "cssparser"
-version = "0.35.0"
+version = "0.36.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e901edd733a1472f944a45116df3f846f54d37e67e68640ac8bb69689aca2aa"
+checksum = "dae61cf9c0abb83bd659dab65b7e4e38d8236824c85f0f804f173567bda257d2"
 dependencies = [
  "cssparser-macros",
  "dtoa-short",
  "itoa",
- "phf 0.11.3",
+ "phf",
  "smallvec",
 ]
 
@@ -1636,6 +1623,12 @@ dependencies = [
  "regex-syntax",
 ]
 
+[[package]]
+name = "fastrand"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f1f227452a390804cdb637b74a86990f2a7d7ba4b7d5693aac9b4dd6defd8d6"
+
 [[package]]
 name = "fdeflate"
 version = "0.3.7"
@@ -1688,16 +1681,6 @@ dependencies = [
  "percent-encoding",
 ]
 
-[[package]]
-name = "futf"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df420e2e84819663797d1ec6544b13c5be84629e7bb00dc960d6917db2987843"
-dependencies = [
- "mac",
- "new_debug_unreachable",
-]
-
 [[package]]
 name = "futures"
 version = "0.3.32"
@@ -2002,6 +1985,11 @@ name = "hashbrown"
 version = "0.17.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
+dependencies = [
+ "allocator-api2",
+ "equivalent",
+ "foldhash 0.2.0",
+]
 
 [[package]]
 name = "headers"
@@ -2054,17 +2042,6 @@ dependencies = [
  "digest 0.11.3",
 ]
 
-[[package]]
-name = "html5ever"
-version = "0.35.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "55d958c2f74b664487a2035fe1dadb032c48718a03b63f3ab0b8537db8549ed4"
-dependencies = [
- "log",
- "markup5ever",
- "match_token",
-]
-
 [[package]]
 name = "http"
 version = "1.4.1"
@@ -2556,6 +2533,25 @@ version = "0.4.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "953f07c43838f8e6f9758cab68bf5bed85465e7587ebe0b823f1bcd81978ad3a"
 
+[[package]]
+name = "lol_html"
+version = "2.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00aad58f6ec3990e795943872f13651e7a5fa59dca2c8f31a74faf8a0e0fb652"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "cssparser",
+ "encoding_rs",
+ "foldhash 0.2.0",
+ "hashbrown 0.17.1",
+ "memchr",
+ "mime",
+ "precomputed-hash",
+ "selectors",
+ "thiserror 2.0.18",
+]
+
 [[package]]
 name = "longest-increasing-subsequence"
 version = "0.1.0"
@@ -2577,12 +2573,6 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "112b39cec0b298b6c1999fee3e31427f74f676e4cb9879ed1a121b43661a4154"
 
-[[package]]
-name = "mac"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c41e0c4fef86961ac6d6f8a82609f55f31b05e4fce149ac5710e439df7619ba4"
-
 [[package]]
 name = "macro-string"
 version = "0.1.4"
@@ -2647,34 +2637,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "maplit"
-version = "1.0.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3e2e65a1a2e43cfcb47a895c4c8b10d1f4a61097f9f254f183aee60cad9c651d"
-
-[[package]]
-name = "markup5ever"
-version = "0.35.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "311fe69c934650f8f19652b3946075f0fc41ad8757dbb68f1ca14e7900ecc1c3"
-dependencies = [
- "log",
- "tendril",
- "web_atoms",
-]
-
-[[package]]
-name = "match_token"
-version = "0.35.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac84fd3f360fcc43dc5f5d186f02a94192761a080e8bc58621ad4d12296a58cf"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "matchers"
 version = "0.2.0"
@@ -3007,68 +2969,50 @@ version = "2.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
-[[package]]
-name = "phf"
-version = "0.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fd6780a80ae0c52cc120a26a1a42c1ae51b247a253e4e06113d23d2c2edd078"
-dependencies = [
- "phf_macros",
- "phf_shared 0.11.3",
-]
-
 [[package]]
 name = "phf"
 version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c1562dc717473dbaa4c1f85a36410e03c047b2e7df7f45ee938fbef64ae7fadf"
 dependencies = [
- "phf_shared 0.13.1",
+ "phf_macros",
+ "phf_shared",
  "serde",
 ]
 
 [[package]]
 name = "phf_codegen"
-version = "0.11.3"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aef8048c789fa5e851558d709946d6d79a8ff88c0440c587967f8e94bfb1216a"
+checksum = "49aa7f9d80421bca176ca8dbfebe668cc7a2684708594ec9f3c0db0805d5d6e1"
 dependencies = [
  "phf_generator",
- "phf_shared 0.11.3",
+ "phf_shared",
 ]
 
 [[package]]
 name = "phf_generator"
-version = "0.11.3"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3c80231409c20246a13fddb31776fb942c38553c51e871f8cbd687a4cfb5843d"
+checksum = "135ace3a761e564ec88c03a77317a7c6b80bb7f7135ef2544dbe054243b89737"
 dependencies = [
- "phf_shared 0.11.3",
+ "fastrand",
- "rand 0.8.6",
+ "phf_shared",
 ]
 
 [[package]]
 name = "phf_macros"
-version = "0.11.3"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84ac04429c13a7ff43785d75ad27569f2951ce0ffd30a3321230db2fc727216"
+checksum = "812f032b54b1e759ccd5f8b6677695d5268c588701effba24601f6932f8269ef"
 dependencies = [
  "phf_generator",
- "phf_shared 0.11.3",
+ "phf_shared",
  "proc-macro2",
  "quote",
  "syn",
 ]
 
-[[package]]
-name = "phf_shared"
-version = "0.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67eabc2ef2a60eb7faa00097bd1ffdb5bd28e62bf39990626a582201b7a754e5"
-dependencies = [
- "siphasher",
-]
-
 [[package]]
 name = "phf_shared"
 version = "0.13.1"
@@ -3675,6 +3619,25 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
+[[package]]
+name = "selectors"
+version = "0.37.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2cfaaa6035167f0e604e42723c7650d59ee269ef220d7bbe0565602c8a0173b9"
+dependencies = [
+ "bitflags",
+ "cssparser",
+ "derive_more",
+ "log",
+ "new_debug_unreachable",
+ "phf",
+ "phf_codegen",
+ "precomputed-hash",
+ "rustc-hash 2.1.2",
+ "servo_arc",
+ "smallvec",
+]
+
 [[package]]
 name = "semver"
 version = "1.0.28"
@@ -3789,6 +3752,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "servo_arc"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "170fb83ab34de17dc69aa7c67482b22218ddb85da56546f9bd6b929e32a05930"
+dependencies = [
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "sha1"
 version = "0.10.6"
@@ -3931,31 +3903,6 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
 
-[[package]]
-name = "string_cache"
-version = "0.8.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf776ba3fa74f83bf4b63c3dcbbf82173db2632ed8452cb2d891d33f459de70f"
-dependencies = [
- "new_debug_unreachable",
- "parking_lot",
- "phf_shared 0.11.3",
- "precomputed-hash",
- "serde",
-]
-
-[[package]]
-name = "string_cache_codegen"
-version = "0.5.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c711928715f1fe0fe509c53b43e993a9a557babc2d0a3567d0a3006f1ac931a0"
-dependencies = [
- "phf_generator",
- "phf_shared 0.11.3",
- "proc-macro2",
- "quote",
-]
-
 [[package]]
 name = "stringprep"
 version = "0.1.5"
@@ -4080,17 +4027,6 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7b2093cf4c8eb1e67749a6762251bc9cd836b6fc171623bd0a9d324d37af2417"
 
-[[package]]
-name = "tendril"
-version = "0.4.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d24a120c5fc464a3458240ee02c299ebcb9d67b5249c8848b09d639dca8d7bb0"
-dependencies = [
- "futf",
- "mac",
- "utf-8",
-]
-
 [[package]]
 name = "thiserror"
 version = "1.0.69"
@@ -4237,7 +4173,7 @@ dependencies = [
  "log",
  "parking_lot",
  "percent-encoding",
- "phf 0.13.1",
+ "phf",
  "pin-project-lite",
  "postgres-protocol",
  "postgres-types",
@@ -4848,18 +4784,6 @@ dependencies = [
  "wasm-bindgen",
 ]
 
-[[package]]
-name = "web_atoms"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57ffde1dc01240bdf9992e3205668b235e59421fd085e8a317ed98da0178d414"
-dependencies = [
- "phf 0.11.3",
- "phf_codegen",
- "string_cache",
- "string_cache_codegen",
-]
-
 [[package]]
 name = "webpki-roots"
 version = "1.0.7"
@@ -5354,7 +5278,6 @@ dependencies = [
 name = "yggdrasil"
 version = "0.2.0"
 dependencies = [
- "ammonia",
  "argon2",
  "axum",
  "chrono",
@@ -5367,6 +5290,7 @@ dependencies = [
  "http",
  "image",
  "js-sys",
+ "lol_html",
  "md-5 0.10.6",
  "moka",
  "pulldown-cmark",

Cargo.toml

@@ -25,7 +25,7 @@ axum = { version = "0.8", optional = true, features = ["multipart"] }
 serde_json = "1.0"
 sha2 = "0.10"
 hex = "0.4"
-ammonia = { version = "4", optional = true }
+lol_html = { version = "2", optional = true }
 syntect = { version = "5", default-features = false, features = ["default-syntaxes", "default-themes", "default-fancy", "html", "parsing", "dump-load", "yaml-load"], optional = true }
 # NOTE: WebP decoder is intentionally excluded from the image crate.
 # We use zenwebp for both encoding and decoding to ensure consistency.
@@ -63,7 +63,7 @@ server = [
     "dep:tracing",
     "dep:tracing-subscriber",
     "dep:tower-http",
-    "dep:ammonia",
+    "dep:lol_html",
     "dep:syntect",
     "dep:axum",
     "dep:image",

src/api/comments/markdown.rs

@@ -8,29 +8,9 @@ fn html_escape(s: &str) -> String {
         .replace('"', """)
 }
 
-#[cfg(feature = "server")]
-static COMMENT_AMMONIA_BUILDER: std::sync::LazyLock<ammonia::Builder> = std::sync::LazyLock::new(|| {
-    let mut builder = ammonia::Builder::default();
-    builder
-        .rm_tags(["img", "details", "summary"])
-        .add_generic_attributes(&[
-            "class",
-            "title",
-            "aria-hidden",
-            "aria-label",
-            "role",
-            "accesskey",
-        ])
-        .url_relative(ammonia::UrlRelative::PassThrough)
-        .add_tag_attributes("a", &["class", "aria-hidden", "aria-label"])
-        .add_tag_attributes("span", &["class"])
-        .link_rel(Some("nofollow noopener"));
-    builder
-});
-
 #[cfg(feature = "server")]
 pub fn clean_comment_html(input: &str) -> String {
-    COMMENT_AMMONIA_BUILDER.clean(input).to_string()
+    crate::api::sanitizer::clean_comment_html(input)
 }
 
 #[cfg(feature = "server")]

src/api/markdown.rs

@@ -1,35 +1,8 @@
 #![allow(clippy::unused_unit, deprecated, unused_imports)]
 
-#[cfg(feature = "server")]
-static AMMONIA_BUILDER: std::sync::LazyLock<ammonia::Builder> = std::sync::LazyLock::new(|| {
-    let mut builder = ammonia::Builder::default();
-    builder
-        .add_generic_attributes(&[
-            "class",
-            "aria-hidden",
-            "aria-label",
-            "id",
-            "role",
-            "accesskey",
-            "title",
-        ])
-        .add_tags(&["details", "summary"])
-        .url_relative(ammonia::UrlRelative::PassThrough)
-        .add_url_schemes(&["data"])
-        .add_tag_attributes("a", &["class", "aria-hidden", "aria-label"])
-        .add_tag_attributes("span", &["class"])
-        .add_tag_attributes("h1", &["id", "class"])
-        .add_tag_attributes("h2", &["id", "class"])
-        .add_tag_attributes("h3", &["id", "class"])
-        .add_tag_attributes("h4", &["id", "class"])
-        .add_tag_attributes("h5", &["id", "class"])
-        .add_tag_attributes("h6", &["id", "class"]);
-    builder
-});
-
 #[cfg(feature = "server")]
 pub fn clean_html(input: &str) -> String {
-    AMMONIA_BUILDER.clean(input).to_string()
+    crate::api::sanitizer::clean_html(input)
 }
 
 #[derive(Debug, Clone)]

src/api/mod.rs

@@ -5,5 +5,6 @@ pub mod image;
 pub mod markdown;
 pub mod posts;
 pub mod rate_limit;
+pub mod sanitizer;
 pub mod slug;
 pub mod upload;

src/api/sanitizer.rs

@@ -0,0 +1,261 @@
+#![allow(clippy::unused_unit, deprecated, unused_imports)]
+
+#[cfg(feature = "server")]
+use std::collections::HashSet;
+
+#[cfg(feature = "server")]
+fn default_allowed_tags() -> HashSet<&'static str> {
+    let mut set = HashSet::new();
+    for tag in [
+        "a", "abbr", "acronym", "area", "article", "aside", "b", "bdi",
+        "bdo", "blockquote", "br", "caption", "center", "cite", "code",
+        "col", "colgroup", "data", "dd", "del", "details", "dfn", "div",
+        "dl", "dt", "em", "figcaption", "figure", "footer", "h1", "h2",
+        "h3", "h4", "h5", "h6", "header", "hgroup", "hr", "i", "img",
+        "ins", "kbd", "li", "map", "mark", "nav", "ol", "p", "pre",
+        "q", "rp", "rt", "rtc", "ruby", "s", "samp", "small", "span",
+        "strike", "strong", "sub", "summary", "sup", "table", "tbody",
+        "td", "th", "thead", "time", "tr", "tt", "u", "ul", "var", "wbr",
+    ] {
+        set.insert(tag);
+    }
+    set
+}
+
+#[cfg(feature = "server")]
+fn clean_content_tags() -> HashSet<&'static str> {
+    let mut set = HashSet::new();
+    set.insert("script");
+    set.insert("style");
+    set
+}
+
+#[cfg(feature = "server")]
+fn default_allowed_schemes() -> HashSet<&'static str> {
+    let mut set = HashSet::new();
+    for scheme in [
+        "bitcoin", "ftp", "ftps", "geo", "http", "https", "im", "irc",
+        "ircs", "magnet", "mailto", "mms", "mx", "news", "nntp",
+        "openpgp4fpr", "sip", "sms", "smsto", "ssh", "tel", "url",
+        "webcal", "wtai", "xmpp",
+    ] {
+        set.insert(scheme);
+    }
+    set
+}
+
+#[cfg(feature = "server")]
+fn is_safe_url(url: &str, allowed_schemes: &HashSet<&str>, allow_data_uri: bool) -> bool {
+    let trimmed = url.trim();
+    if trimmed.is_empty() {
+        return true;
+    }
+    if let Some(colon_pos) = trimmed.find(':') {
+        let scheme = &trimmed[..colon_pos];
+        let scheme_lower = scheme.to_lowercase();
+        if allowed_schemes.contains(scheme_lower.as_str()) {
+            return true;
+        }
+        if scheme_lower == "data" {
+            return allow_data_uri;
+        }
+        if scheme_lower == "javascript" || scheme_lower == "vbscript" {
+            return false;
+        }
+        if scheme.contains(|c: char| c.is_ascii_whitespace()) {
+            return false;
+        }
+    }
+    if trimmed.starts_with('#') || trimmed.starts_with('/') {
+        return true;
+    }
+    true
+}
+
+#[cfg(feature = "server")]
+struct SanitizerConfig {
+    allowed_tags: HashSet<&'static str>,
+    extra_generic_attrs: Vec<&'static str>,
+    extra_tag_attrs: Vec<(&'static str, Vec<&'static str>)>,
+    allowed_schemes: HashSet<&'static str>,
+    allow_data_uri: bool,
+    link_rel: Option<&'static str>,
+    remove_tags: HashSet<&'static str>,
+}
+
+#[cfg(feature = "server")]
+fn sanitize(input: &str, config: &SanitizerConfig) -> String {
+    let allowed_tags = config.allowed_tags.clone();
+    let remove_tags = config.remove_tags.clone();
+    let generic_attrs: HashSet<&str> = config
+        .extra_generic_attrs
+        .iter()
+        .copied()
+        .chain(["lang", "title"])
+        .collect();
+    let tag_attrs_map: std::collections::HashMap<&str, HashSet<&str>> = {
+        let mut m = std::collections::HashMap::new();
+        let base = [
+            ("a", vec!["href", "hreflang"]),
+            ("bdo", vec!["dir"]),
+            ("blockquote", vec!["cite"]),
+            ("col", vec!["align", "char", "charoff", "span"]),
+            ("colgroup", vec!["align", "char", "charoff", "span"]),
+            ("del", vec!["cite", "datetime"]),
+            ("hr", vec!["align", "size", "width"]),
+            ("img", vec!["align", "alt", "height", "src", "width"]),
+            ("ins", vec!["cite", "datetime"]),
+            ("ol", vec!["start"]),
+            ("q", vec!["cite"]),
+            ("table", vec!["align", "char", "charoff", "summary"]),
+            ("tbody", vec!["align", "char", "charoff"]),
+            ("td", vec!["align", "char", "charoff", "colspan", "headers", "rowspan"]),
+            ("tfoot", vec!["align", "char", "charoff"]),
+            ("th", vec!["align", "char", "charoff", "colspan", "headers", "rowspan", "scope"]),
+            ("thead", vec!["align", "char", "charoff"]),
+            ("tr", vec!["align", "char", "charoff"]),
+        ];
+        for (tag, attrs) in &base {
+            m.insert(*tag, attrs.iter().copied().collect());
+        }
+        for (tag, attrs) in &config.extra_tag_attrs {
+            m.entry(tag)
+                .or_insert_with(HashSet::new)
+                .extend(attrs.iter().copied());
+        }
+        m
+    };
+    let allowed_schemes = config.allowed_schemes.clone();
+    let allow_data_uri = config.allow_data_uri;
+    let link_rel = config.link_rel;
+
+    let element_handler = move |el: &mut lol_html::html_content::Element| {
+        let tag = el.tag_name().to_lowercase();
+
+        if remove_tags.contains(tag.as_str()) {
+            el.remove();
+            return Ok(());
+        }
+
+        if !allowed_tags.contains(tag.as_str()) {
+            el.remove_and_keep_content();
+            return Ok(());
+        }
+
+        let allowed_for_tag: HashSet<&str> = {
+            let mut s = generic_attrs.clone();
+            if let Some(tag_specific) = tag_attrs_map.get(tag.as_str()) {
+                s.extend(tag_specific.iter().copied());
+            }
+            s
+        };
+
+        let attrs_to_remove: Vec<String> = el
+            .attributes()
+            .iter()
+            .filter_map(|attr| {
+                let name = attr.name();
+                let name_lower = name.to_lowercase();
+                if allowed_for_tag.contains(name_lower.as_str()) {
+                    if name_lower == "href" || name_lower == "src" || name_lower == "cite" {
+                        let val = attr.value();
+                        if !is_safe_url(&val, &allowed_schemes, allow_data_uri) {
+                            return Some(name);
+                        }
+                    }
+                    None
+                } else {
+                    Some(name)
+                }
+            })
+            .collect();
+
+        for attr_name in attrs_to_remove {
+            el.remove_attribute(&attr_name);
+        }
+
+        if link_rel.is_some() && tag == "a" {
+            if let Some(rel) = link_rel {
+                let existing = el.get_attribute("rel").unwrap_or_default();
+                if existing != rel {
+                    el.set_attribute("rel", rel).ok();
+                }
+            }
+        }
+
+        Ok(())
+    };
+
+    lol_html::rewrite_str(
+        input,
+        lol_html::RewriteStrSettings {
+            element_content_handlers: vec![lol_html::element!("*", element_handler)],
+            document_content_handlers: vec![lol_html::doc_comments!(|c| {
+                c.remove();
+                Ok(())
+            })],
+            ..lol_html::RewriteStrSettings::new()
+        },
+    )
+    .unwrap_or_default()
+}
+
+#[cfg(feature = "server")]
+pub fn clean_html(input: &str) -> String {
+    let config = SanitizerConfig {
+        allowed_tags: default_allowed_tags(),
+        extra_generic_attrs: vec![
+            "class",
+            "aria-hidden",
+            "aria-label",
+            "id",
+            "role",
+            "accesskey",
+            "title",
+        ],
+        extra_tag_attrs: vec![
+            ("a", vec!["class", "aria-hidden", "aria-label"]),
+            ("span", vec!["class"]),
+            ("h1", vec!["id", "class"]),
+            ("h2", vec!["id", "class"]),
+            ("h3", vec!["id", "class"]),
+            ("h4", vec!["id", "class"]),
+            ("h5", vec!["id", "class"]),
+            ("h6", vec!["id", "class"]),
+        ],
+        allowed_schemes: default_allowed_schemes(),
+        allow_data_uri: true,
+        link_rel: Some("noopener noreferrer"),
+        remove_tags: clean_content_tags(),
+    };
+    sanitize(input, &config)
+}
+
+#[cfg(feature = "server")]
+pub fn clean_comment_html(input: &str) -> String {
+    let mut tags = default_allowed_tags();
+    tags.remove("img");
+    tags.remove("details");
+    tags.remove("summary");
+
+    let config = SanitizerConfig {
+        allowed_tags: tags,
+        extra_generic_attrs: vec![
+            "class",
+            "title",
+            "aria-hidden",
+            "aria-label",
+            "role",
+            "accesskey",
+        ],
+        extra_tag_attrs: vec![
+            ("a", vec!["class", "aria-hidden", "aria-label"]),
+            ("span", vec!["class"]),
+        ],
+        allowed_schemes: default_allowed_schemes(),
+        allow_data_uri: false,
+        link_rel: Some("nofollow noopener"),
+        remove_tags: clean_content_tags(),
+    };
+    sanitize(input, &config)
+}