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#![allow(clippy::disallowed_types)]
use std::collections::{HashMap, HashSet};
pub(crate) mod clean;
use crate::HtmlSanitizerMode;
/// Configuration to sanitize HTML elements and attributes.
#[derive(Debug, Default, Clone)]
pub struct SanitizerConfig {
/// The mode of the sanitizer, if any.
mode: Option<HtmlSanitizerMode>,
/// Change to the list of elements to replace.
///
/// The content is a map of element name to their replacement's element name.
replace_elements: Option<List<HashMap<&'static str, &'static str>>>,
/// Elements to remove.
remove_elements: Option<HashSet<&'static str>>,
/// Whether to remove the rich reply fallback.
remove_reply_fallback: bool,
/// Elements to ignore.
ignore_elements: Option<HashSet<&'static str>>,
/// Change to the list of elements to allow.
allow_elements: Option<List<HashSet<&'static str>>>,
/// Change to the list of attributes to replace per element.
///
/// The content is a map of element name to a map of attribute name to their replacement's
/// attribute name.
replace_attrs: Option<List<HashMap<&'static str, HashMap<&'static str, &'static str>>>>,
/// Removed attributes per element.
remove_attrs: Option<HashMap<&'static str, HashSet<&'static str>>>,
/// Change to the list of allowed attributes per element.
allow_attrs: Option<List<HashMap<&'static str, HashSet<&'static str>>>>,
/// Denied URI schemes per attribute per element.
///
/// The content is a map of element name to a map of attribute name to a set of schemes.
deny_schemes: Option<HashMap<&'static str, HashMap<&'static str, HashSet<&'static str>>>>,
/// Change to the list of allowed URI schemes per attribute per element.
///
/// The content is a map of element name to a map of attribute name to a set of schemes.
#[allow(clippy::type_complexity)]
allow_schemes:
Option<List<HashMap<&'static str, HashMap<&'static str, HashSet<&'static str>>>>>,
/// Removed classes per element.
///
/// The content is a map of element name to a set of classes.
remove_classes: Option<HashMap<&'static str, HashSet<&'static str>>>,
/// Change to the list of allowed classes per element.
///
/// The content is a map of element name to a set of classes.
allow_classes: Option<List<HashMap<&'static str, HashSet<&'static str>>>>,
/// Maximum nesting level of the elements.
max_depth: Option<u32>,
}
impl SanitizerConfig {
/// Constructs an empty `SanitizerConfig` that will not filter any element or attribute.
///
/// The list of allowed and replaced elements can be changed with [`Self::allow_elements()`],
/// [`Self::replace_elements()`], [`Self::ignore_elements()`], [`Self::remove_elements()`],
/// [`Self::remove_reply_fallback()`].
///
/// The list of allowed and replaced attributes can be changed with
/// [`Self::allow_attributes()`], [`Self::replace_attributes()`],
/// [`Self::remove_attributes()`], [`Self::allow_schemes()`], [`Self::deny_schemes()`],
/// [`Self::allow_classes()`], [`Self::remove_classes()`].
pub fn new() -> Self {
Self::default()
}
/// Constructs a `SanitizerConfig` with the given mode for filtering elements and attributes.
///
/// The mode defines the basic list of allowed and replaced elements and attributes and the
/// maximum nesting level of elements.
///
/// The list of allowed and replaced elements can be changed with [`Self::allow_elements()`],
/// [`Self::replace_elements()`], [`Self::ignore_elements()`], [`Self::remove_elements()`],
/// [`Self::remove_reply_fallback()`].
///
/// The list of allowed and replaced attributes can be changed with
/// [`Self::allow_attributes()`], [`Self::replace_attributes()`],
/// [`Self::remove_attributes()`], [`Self::allow_schemes()`], [`Self::deny_schemes()`],
/// [`Self::allow_classes()`], [`Self::remove_classes()`].
pub fn with_mode(mode: HtmlSanitizerMode) -> Self {
Self { mode: Some(mode), ..Default::default() }
}
/// Constructs a `SanitizerConfig` that will filter elements and attributes not [suggested in
/// the Matrix specification].
///
/// The list of allowed and replaced elements can be changed with [`Self::allow_elements()`],
/// [`Self::replace_elements()`], [`Self::ignore_elements()`], [`Self::remove_elements()`],
/// [`Self::remove_reply_fallback()`].
///
/// The list of allowed and replaced attributes can be changed with
/// [`Self::allow_attributes()`], [`Self::replace_attributes()`],
/// [`Self::remove_attributes()`], [`Self::allow_schemes()`], [`Self::deny_schemes()`],
/// [`Self::allow_classes()`], [`Self::remove_classes()`].
///
/// This is the same as calling `SanitizerConfig::with_mode(HtmlSanitizerMode::Strict)`.
///
/// [suggested in the Matrix specification]: https://spec.matrix.org/latest/client-server-api/#mroommessage-msgtypes
pub fn strict() -> Self {
Self::with_mode(HtmlSanitizerMode::Strict)
}
/// Constructs a `SanitizerConfig` that will filter elements and attributes not [suggested in
/// the Matrix specification], except a few for improved compatibility:
///
/// * The `matrix` scheme is allowed in links.
///
/// The list of allowed elements can be changed with [`Self::allow_elements()`],
/// [`Self::replace_elements()`], [`Self::ignore_elements()`], [`Self::remove_elements()`],
/// [`Self::remove_reply_fallback()`].
///
/// The list of allowed attributes can be changed with [`Self::allow_attributes()`],
/// [`Self::replace_attributes()`], [`Self::remove_attributes()`], [`Self::allow_schemes()`],
/// [`Self::deny_schemes()`], [`Self::allow_classes()`], [`Self::remove_classes()`].
///
/// This is the same as calling `SanitizerConfig::with_mode(HtmlSanitizerMode::Compat)`.
///
/// [listed in the Matrix specification]: https://spec.matrix.org/latest/client-server-api/#mroommessage-msgtypes
pub fn compat() -> Self {
Self::with_mode(HtmlSanitizerMode::Compat)
}
/// Change the list of replaced HTML elements.
///
/// The given list is added to or replaces the list of replacements of the current mode,
/// depending on the [`ListBehavior`].
///
/// The replacement occurs before the removal, so the replaced element should not be in
/// the allowed list of elements, but the replacement element should.
///
/// # Parameters
///
/// * `elements`: The list of element names replacements.
pub fn replace_elements(
mut self,
elements: impl IntoIterator<Item = NameReplacement>,
behavior: ListBehavior,
) -> Self {
let content = elements.into_iter().map(|r| r.to_tuple()).collect();
self.replace_elements = Some(List { content, behavior });
self
}
/// Remove the given HTML elements.
///
/// When an element is removed, the element and its children are dropped. If you want to remove
/// an element but keep its children, use [`SanitizerConfig::ignore_elements`] or
/// [`SanitizerConfig::allow_elements`].
///
/// Removing elements has a higher priority than ignoring or allowing. So if an element is in
/// this list, it will always be removed.
///
/// # Parameters
///
/// * `elements`: The list of element names to remove.
pub fn remove_elements(mut self, elements: impl IntoIterator<Item = &'static str>) -> Self {
self.remove_elements = Some(elements.into_iter().collect());
self
}
/// Remove the [rich reply fallback].
///
/// Calling this allows to remove the `mx-reply` element in addition to the list of elements to
/// remove.
///
/// Removing elements has a higher priority than ignoring or allowing. So if this settings is
/// set, `mx-reply` will always be removed.
///
/// [rich reply fallback]: https://spec.matrix.org/latest/client-server-api/#fallbacks-for-rich-replies
pub fn remove_reply_fallback(mut self) -> Self {
self.remove_reply_fallback = true;
self
}
/// Ignore the given HTML elements.
///
/// When an element is ignored, the element is dropped and replaced by its children. If you want
/// to drop an element and its children, use [`SanitizerConfig::remove_elements`].
///
/// Removing elements has a lower priority than removing but a higher priority than allowing.
///
/// # Parameters
///
/// * `elements`: The list of element names to ignore.
pub fn ignore_elements(mut self, elements: impl IntoIterator<Item = &'static str>) -> Self {
self.ignore_elements = Some(elements.into_iter().collect());
self
}
/// Change the list of allowed HTML elements.
///
/// The given list is added to or replaces the list of allowed elements of the current
/// mode, depending on the [`ListBehavior`].
///
/// If an element is not allowed, it is ignored. If no mode is set and no elements are
/// explicitly allowed, all elements are allowed.
///
/// # Parameters
///
/// * `elements`: The list of element names.
pub fn allow_elements(
mut self,
elements: impl IntoIterator<Item = &'static str>,
behavior: ListBehavior,
) -> Self {
let content = elements.into_iter().collect();
self.allow_elements = Some(List { content, behavior });
self
}
/// Change the list of replaced attributes per HTML element.
///
/// The given list is added to or replaces the list of replacements of the current mode,
/// depending on the [`ListBehavior`].
///
/// The replacement occurs before the removal, so the replaced attribute should not be in the
/// list of allowed attributes, but the replacement attribute should. Attribute replacement
/// occurs before element replacement, so if you want to replace an attribute on an element
/// that is set to be replaced, you must use the replaced element's name, not the name of its
/// replacement.
///
/// # Parameters
///
/// * `attrs`: The list of element's attributes replacements.
pub fn replace_attributes<'a>(
mut self,
attrs: impl IntoIterator<Item = ElementAttributesReplacement<'a>>,
behavior: ListBehavior,
) -> Self {
let content = attrs.into_iter().map(|r| r.to_tuple()).collect();
self.replace_attrs = Some(List { content, behavior });
self
}
/// Remove the given attributes per HTML element.
///
/// Removing attributes has a higher priority than allowing. So if an attribute is in
/// this list, it will always be removed.
///
/// # Parameters
///
/// * `attrs`: The list of attributes per element. The value of `parent` is the element name,
/// and `properties` contains attribute names.
pub fn remove_attributes<'a>(
mut self,
attrs: impl IntoIterator<Item = PropertiesNames<'a>>,
) -> Self {
self.remove_attrs = Some(attrs.into_iter().map(|a| a.to_tuple()).collect());
self
}
/// Change the list of allowed attributes per HTML element.
///
/// The given list is added to or replaces the list of allowed attributes of the current
/// mode, depending on the [`ListBehavior`].
///
/// If an attribute is not allowed, it is removed. If no mode is set and no attributes are
/// explicitly allowed, all attributes are allowed.
///
/// # Parameters
///
/// * `attrs`: The list of attributes per element. The value of `parent` is the element name,
/// and `properties` contains attribute names.
pub fn allow_attributes<'a>(
mut self,
attrs: impl IntoIterator<Item = PropertiesNames<'a>>,
behavior: ListBehavior,
) -> Self {
let content = attrs.into_iter().map(|a| a.to_tuple()).collect();
self.allow_attrs = Some(List { content, behavior });
self
}
/// Deny the given URI schemes per attribute per HTML element.
///
/// Denying schemes has a higher priority than allowing. So if a scheme is in
/// this list, it will always be denied.
///
/// If a scheme is denied, its element is removed, because it is deemed that the element will
/// not be usable without it URI.
///
/// # Parameters
///
/// * `schemes`: The list of schemes per attribute per element.
pub fn deny_schemes<'a>(
mut self,
schemes: impl IntoIterator<Item = ElementAttributesSchemes<'a>>,
) -> Self {
self.deny_schemes = Some(schemes.into_iter().map(|s| s.to_tuple()).collect());
self
}
/// Change the list of allowed schemes per attribute per HTML element.
///
/// The given list is added to or replaces the list of allowed schemes of the current
/// mode, depending on the [`ListBehavior`].
///
/// If a scheme is not allowed, it is denied. If a scheme is denied, its element is ignored,
/// because it is deemed that the element will not be usable without it URI. If no mode is set
/// and no schemes are explicitly allowed, all schemes are allowed.
///
/// # Parameters
///
/// * `schemes`: The list of schemes per attribute per element.
pub fn allow_schemes<'a>(
mut self,
schemes: impl IntoIterator<Item = ElementAttributesSchemes<'a>>,
behavior: ListBehavior,
) -> Self {
let content = schemes.into_iter().map(|s| s.to_tuple()).collect();
self.allow_schemes = Some(List { content, behavior });
self
}
/// Deny the given classes per HTML element.
///
/// Removing classes has a higher priority than allowing. So if a class is in
/// this list, it will always be removed.
///
/// If all the classes of a `class` attribute are removed, the whole attribute is removed.
///
/// In the list of classes, the names must match the full class name. `*` can be used as a
/// wildcard for any number of characters. So `language` will only match a class named
/// `language`, and `language-*` will match any class name starting with `language-`.
///
/// # Parameters
///
/// * `attrs`: The list of classes per element. The value of `parent` is the element name, and
/// `properties` contains classes.
pub fn remove_classes<'a>(
mut self,
classes: impl IntoIterator<Item = PropertiesNames<'a>>,
) -> Self {
self.remove_classes = Some(classes.into_iter().map(|c| c.to_tuple()).collect());
self
}
/// Change the list of allowed classes per HTML element.
///
/// The given list is added, removed or replaces the list of allowed classes of the current
/// mode, depending on the [`ListBehavior`].
///
/// If a class is not allowed, it is removed. If all the classes of a `class` attribute are
/// removed, the whole attribute is removed. If no mode is set and no classes are explicitly
/// allowed, all classes are allowed.
///
/// In the list of classes, the names must match the full class name. `*` can be used as a
/// wildcard for any number of characters. So `language` will only match a class named
/// `language`, and `language-*` will match any class name starting with `language-`.
///
/// # Parameters
///
/// * `attrs`: The list of classes per element. The value of `parent` is the element name, and
/// `properties` contains classes.
pub fn allow_classes<'a>(
mut self,
classes: impl IntoIterator<Item = PropertiesNames<'a>>,
behavior: ListBehavior,
) -> Self {
let content = classes.into_iter().map(|c| c.to_tuple()).collect();
self.allow_classes = Some(List { content, behavior });
self
}
/// The maximum nesting level of HTML elements.
///
/// This overrides the maximum depth set by the mode, if one is set.
///
/// All elements that are deeper than the maximum depth will be removed. If no mode is set and
/// no maximum depth is explicitly set, elements are not filtered by their nesting level.
///
/// # Parameters
///
/// * `depth`: The maximum nesting level allowed.
pub fn max_depth(mut self, depth: u32) -> Self {
self.max_depth = Some(depth);
self
}
}
/// A list with a behavior.
#[derive(Debug, Clone)]
struct List<T> {
/// The content of this list.
content: T,
/// The behavior of this list.
behavior: ListBehavior,
}
impl<T> List<T> {
/// Whether this is `ListBehavior::Override`.
fn is_override(&self) -> bool {
self.behavior == ListBehavior::Override
}
}
/// The behavior of the setting.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[allow(clippy::exhaustive_enums)]
pub enum ListBehavior {
/// The list replaces the default list of the current mode, if one is set.
///
/// If no mode is set, this is the full allow list.
Override,
/// The list is added to the default list of the current mode, if one is set.
///
/// If no mode is set, this is the full allow list.
Add,
}
/// The replacement of a name.
#[derive(Debug, Clone, Copy)]
#[allow(clippy::exhaustive_structs)]
pub struct NameReplacement {
/// The name to replace.
pub old: &'static str,
/// The name of the replacement.
pub new: &'static str,
}
impl NameReplacement {
fn to_tuple(self) -> (&'static str, &'static str) {
(self.old, self.new)
}
}
/// A list of properties names for a parent.
#[allow(clippy::exhaustive_structs)]
#[derive(Debug, Clone, Copy)]
pub struct PropertiesNames<'a> {
/// The name of the parent.
pub parent: &'static str,
/// The list of properties names.
pub properties: &'a [&'static str],
}
impl<'a> PropertiesNames<'a> {
fn to_tuple(self) -> (&'static str, HashSet<&'static str>) {
let set = self.properties.iter().copied().collect();
(self.parent, set)
}
}
/// The replacement of an element's attributes.
#[allow(clippy::exhaustive_structs)]
#[derive(Debug, Clone, Copy)]
pub struct ElementAttributesReplacement<'a> {
/// The name of the element.
pub element: &'static str,
/// The list of attributes replacements.
pub replacements: &'a [NameReplacement],
}
impl<'a> ElementAttributesReplacement<'a> {
fn to_tuple(self) -> (&'static str, HashMap<&'static str, &'static str>) {
let map = self.replacements.iter().map(|r| r.to_tuple()).collect();
(self.element, map)
}
}
/// An element's attributes' URI schemes.
#[allow(clippy::exhaustive_structs)]
#[derive(Debug, Clone, Copy)]
pub struct ElementAttributesSchemes<'a> {
/// The name of the element.
pub element: &'static str,
/// The list of allowed URI schemes per attribute name.
///
/// The value of the `parent` is the attribute name and the properties are schemes.
pub attr_schemes: &'a [PropertiesNames<'a>],
}
impl<'a> ElementAttributesSchemes<'a> {
fn to_tuple(self) -> (&'static str, HashMap<&'static str, HashSet<&'static str>>) {
let map = self.attr_schemes.iter().map(|s| s.to_tuple()).collect();
(self.element, map)
}
}