Add simple implementation of content-security-policy on scripts / styles

This needs a lot more hooks before it'll actually be a good
implementation, but for a start it can help get some feedback on if this
is the right way to go about it.

Part of servo#4577

Author: notriddle

Cargo.lock

@@ -21,10 +21,12 @@ servo = [
     "url",
     "webrender_api",
     "xml5ever",
+    "content-security-policy",
 ]
 
 [dependencies]
 app_units = "0.7"
+content-security-policy = {version = "0.3.0", features = ["serde"], optional = true}
 crossbeam-channel = { version = "0.3", optional = true }
 cssparser = "0.25"
 euclid = "0.20"

components/malloc_size_of/Cargo.toml

@@ -48,6 +48,8 @@
 
 extern crate app_units;
 #[cfg(feature = "servo")]
+extern crate content_security_policy;
+#[cfg(feature = "servo")]
 extern crate crossbeam_channel;
 extern crate cssparser;
 extern crate euclid;
@@ -79,6 +81,8 @@ extern crate webrender_api;
 #[cfg(feature = "servo")]
 extern crate xml5ever;
 
+#[cfg(feature = "servo")]
+use content_security_policy as csp;
 #[cfg(feature = "servo")]
 use serde_bytes::ByteBuf;
 use std::hash::{BuildHasher, Hash};
@@ -833,6 +837,8 @@ malloc_size_of_is_0!(app_units::Au);
 
 malloc_size_of_is_0!(cssparser::RGBA, cssparser::TokenSerializationType);
 
+malloc_size_of_is_0!(csp::Destination);
+
 #[cfg(feature = "url")]
 impl MallocSizeOf for url::Host {
     fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {

components/malloc_size_of/lib.rs

@@ -17,6 +17,7 @@ doctest = false
 base64 = "0.10.1"
 brotli = "3"
 bytes = "0.4"
+content-security-policy = {version = "0.3.0", features = ["serde"]}
 cookie_rs = {package = "cookie", version = "0.11"}
 crossbeam-channel = "0.3"
 devtools_traits = {path = "../devtools_traits"}

components/net/Cargo.toml

@@ -8,6 +8,7 @@ use crate::filemanager_thread::{fetch_file_in_chunks, FileManager, FILE_CHUNK_SI
 use crate::http_loader::{determine_request_referrer, http_fetch, HttpState};
 use crate::http_loader::{set_default_accept, set_default_accept_language};
 use crate::subresource_integrity::is_response_integrity_valid;
+use content_security_policy as csp;
 use crossbeam_channel::{unbounded, Receiver, Sender};
 use devtools_traits::DevtoolsControlMsg;
 use headers::{AccessControlExposeHeaders, ContentType, HeaderMapExt, Range};
@@ -138,6 +139,30 @@ pub fn fetch_with_cors_cache(
     main_fetch(request, cache, false, false, target, &mut None, &context);
 }
 
+/// https://www.w3.org/TR/CSP/#should-block-request
+pub fn should_request_be_blocked_by_csp(request: &Request) -> csp::CheckResult {
+    let origin = match &request.origin {
+        Origin::Client => return csp::CheckResult::Allowed,
+        Origin::Origin(origin) => origin,
+    };
+    let csp_request = csp::Request {
+        url: request.url().into_url(),
+        origin: origin.clone().into_url_origin(),
+        redirect_count: request.redirect_count,
+        destination: request.destination,
+        initiator: csp::Initiator::None,
+        nonce: String::new(),
+        integrity_metadata: request.integrity_metadata.clone(),
+        parser_metadata: csp::ParserMetadata::None,
+    };
+    // TODO: Instead of ignoring violations, report them.
+    request
+        .csp_list
+        .as_ref()
+        .map(|c| c.should_request_be_blocked(&csp_request).0)
+        .unwrap_or(csp::CheckResult::Allowed)
+}
+
 /// [Main fetch](https://fetch.spec.whatwg.org/#concept-main-fetch)
 pub fn main_fetch(
     request: &mut Request,
@@ -163,8 +188,18 @@ pub fn main_fetch(
         }
     }
 
+    // Step 2.2.
+    // TODO: Report violations.
+
+    // Step 2.4.
+    if should_request_be_blocked_by_csp(request) == csp::CheckResult::Blocked {
+        response = Some(Response::network_error(NetworkError::Internal(
+            "Blocked by Content-Security-Policy".into(),
+        )))
+    }
+
     // Step 3.
-    // TODO: handle content security policy violations.
+    // TODO: handle request abort.
 
     // Step 4.
     // TODO: handle upgrade to a potentially secure URL.

components/net/fetch/methods.rs

@@ -13,6 +13,7 @@ test = false
 doctest = false
 
 [dependencies]
+content-security-policy = {version = "0.3.0", features = ["serde"]}
 cookie = "0.11"
 embedder_traits = { path = "../embedder_traits" }
 headers = "0.2"

components/net_traits/Cargo.toml

@@ -4,6 +4,7 @@
 
 use crate::ReferrerPolicy;
 use crate::ResourceTimingType;
+use content_security_policy::{self as csp, CspList};
 use http::HeaderMap;
 use hyper::Method;
 use msg::constellation_msg::PipelineId;
@@ -20,37 +21,7 @@ pub enum Initiator {
 }
 
 /// A request [destination](https://fetch.spec.whatwg.org/#concept-request-destination)
-#[derive(Clone, Copy, Debug, Deserialize, MallocSizeOf, PartialEq, Serialize)]
-pub enum Destination {
-    None,
-    Audio,
-    Document,
-    Embed,
-    Font,
-    Image,
-    Manifest,
-    Object,
-    Report,
-    Script,
-    ServiceWorker,
-    SharedWorker,
-    Style,
-    Track,
-    Video,
-    Worker,
-    Xslt,
-}
-
-impl Destination {
-    /// https://fetch.spec.whatwg.org/#request-destination-script-like
-    #[inline]
-    pub fn is_script_like(&self) -> bool {
-        *self == Destination::Script ||
-            *self == Destination::ServiceWorker ||
-            *self == Destination::SharedWorker ||
-            *self == Destination::Worker
-    }
-}
+pub use csp::Destination;
 
 /// A request [origin](https://fetch.spec.whatwg.org/#concept-request-origin)
 #[derive(Clone, Debug, Deserialize, MallocSizeOf, PartialEq, Serialize)]
@@ -175,6 +146,11 @@ pub struct RequestBuilder {
     pub pipeline_id: Option<PipelineId>,
     pub redirect_mode: RedirectMode,
     pub integrity_metadata: String,
+    // This is nominally a part of the client's global object.
+    // It is copied here to avoid having to reach across the thread
+    // boundary every time a redirect occurs.
+    #[ignore_malloc_size_of = "Defined in rust-content-security-policy"]
+    pub csp_list: Option<CspList>,
     // to keep track of redirects
     pub url_list: Vec<ServoUrl>,
     pub parser_metadata: ParserMetadata,
@@ -206,6 +182,7 @@ impl RequestBuilder {
             url_list: vec![],
             parser_metadata: ParserMetadata::Default,
             initiator: Initiator::None,
+            csp_list: None,
         }
     }
 
@@ -329,6 +306,7 @@ impl RequestBuilder {
         request.url_list = url_list;
         request.integrity_metadata = self.integrity_metadata;
         request.parser_metadata = self.parser_metadata;
+        request.csp_list = self.csp_list;
         request
     }
 }
@@ -396,6 +374,11 @@ pub struct Request {
     pub response_tainting: ResponseTainting,
     /// <https://fetch.spec.whatwg.org/#concept-request-parser-metadata>
     pub parser_metadata: ParserMetadata,
+    // This is nominally a part of the client's global object.
+    // It is copied here to avoid having to reach across the thread
+    // boundary every time a redirect occurs.
+    #[ignore_malloc_size_of = "Defined in rust-content-security-policy"]
+    pub csp_list: Option<CspList>,
 }
 
 impl Request {
@@ -428,6 +411,7 @@ impl Request {
             parser_metadata: ParserMetadata::Default,
             redirect_count: 0,
             response_tainting: ResponseTainting::Basic,
+            csp_list: None,
         }
     }
 

components/net_traits/request.rs

@@ -38,6 +38,7 @@ bitflags = "1.0"
 bluetooth_traits = {path = "../bluetooth_traits"}
 canvas_traits = {path = "../canvas_traits"}
 caseless = "0.2"
+content-security-policy = {version = "0.3.0", features = ["serde"]}
 cookie = "0.11"
 chrono = "0.4"
 crossbeam-channel = "0.3"

components/script/Cargo.toml

@@ -54,6 +54,7 @@ use canvas_traits::webgl::{
 use canvas_traits::webgl::{WebGLFramebufferId, WebGLMsgSender, WebGLPipeline, WebGLProgramId};
 use canvas_traits::webgl::{WebGLReceiver, WebGLRenderbufferId, WebGLSLVersion, WebGLSender};
 use canvas_traits::webgl::{WebGLShaderId, WebGLSyncId, WebGLTextureId, WebGLVersion};
+use content_security_policy::CspList;
 use crossbeam_channel::{Receiver, Sender};
 use cssparser::RGBA;
 use devtools_traits::{CSSError, TimelineMarkerType, WorkerId};
@@ -170,6 +171,8 @@ unsafe_no_jsmanaged_fields!(*mut JobQueue);
 
 unsafe_no_jsmanaged_fields!(Cow<'static, str>);
 
+unsafe_no_jsmanaged_fields!(CspList);
+
 /// Trace a `JSVal`.
 pub fn trace_jsval(tracer: *mut JSTracer, description: &str, val: &Heap<JSVal>) {
     unsafe {

components/script/dom/bindings/trace.rs

@@ -110,6 +110,7 @@ use crate::task::TaskBox;
 use crate::task_source::{TaskSource, TaskSourceName};
 use crate::timers::OneshotTimerCallback;
 use canvas_traits::webgl::{self, WebGLContextId, WebGLMsg};
+use content_security_policy::{self as csp, CspList};
 use cookie::Cookie;
 use devtools_traits::ScriptToDevtoolsControlMsg;
 use dom_struct::dom_struct;
@@ -137,6 +138,7 @@ use num_traits::ToPrimitive;
 use percent_encoding::percent_decode;
 use profile_traits::ipc as profile_ipc;
 use profile_traits::time::{TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType};
+use ref_filter_map::ref_filter_map;
 use ref_slice::ref_slice;
 use script_layout_interface::message::{Msg, ReflowGoal};
 use script_traits::{AnimationState, DocumentActivity, MouseButton, MouseEventType};
@@ -148,7 +150,7 @@ use servo_atoms::Atom;
 use servo_config::pref;
 use servo_media::{ClientContextId, ServoMedia};
 use servo_url::{ImmutableOrigin, MutableOrigin, ServoUrl};
-use std::borrow::ToOwned;
+use std::borrow::Cow;
 use std::cell::{Cell, Ref, RefMut};
 use std::collections::hash_map::Entry::{Occupied, Vacant};
 use std::collections::{HashMap, HashSet, VecDeque};
@@ -398,6 +400,9 @@ pub struct Document {
     media_controls: DomRefCell<HashMap<String, Dom<ShadowRoot>>>,
     /// List of all WebGL context IDs that need flushing.
     dirty_webgl_contexts: DomRefCell<HashSet<WebGLContextId>>,
+    /// https://html.spec.whatwg.org/multipage/#concept-document-csp-list
+    #[ignore_malloc_size_of = "Defined in rust-content-security-policy"]
+    csp_list: DomRefCell<Option<CspList>>,
 }
 
 #[derive(JSTraceable, MallocSizeOf)]
@@ -1734,9 +1739,10 @@ impl Document {
     pub fn fetch_async(
         &self,
         load: LoadType,
-        request: RequestBuilder,
+        mut request: RequestBuilder,
         fetch_target: IpcSender<FetchResponseMsg>,
     ) {
+        request.csp_list = self.get_csp_list().map(|x| x.clone());
         let mut loader = self.loader.borrow_mut();
         loader.fetch_async(load, request, fetch_target);
     }
@@ -2806,9 +2812,39 @@ impl Document {
             shadow_roots_styles_changed: Cell::new(false),
             media_controls: DomRefCell::new(HashMap::new()),
             dirty_webgl_contexts: DomRefCell::new(HashSet::new()),
+            csp_list: DomRefCell::new(None),
         }
     }
 
+    pub fn set_csp_list(&self, csp_list: Option<CspList>) {
+        *self.csp_list.borrow_mut() = csp_list;
+    }
+
+    pub fn get_csp_list(&self) -> Option<Ref<CspList>> {
+        ref_filter_map(self.csp_list.borrow(), Option::as_ref)
+    }
+
+    /// https://www.w3.org/TR/CSP/#should-block-inline
+    pub fn should_elements_inline_type_behavior_be_blocked(
+        &self,
+        el: &Element,
+        type_: csp::InlineCheckType,
+        source: &str,
+    ) -> csp::CheckResult {
+        let element = csp::Element {
+            nonce: el
+                .get_attribute(&ns!(), &local_name!("nonce"))
+                .map(|attr| Cow::Owned(attr.value().to_string())),
+        };
+        // TODO: Instead of ignoring violations, report them.
+        self.get_csp_list()
+            .map(|c| {
+                c.should_elements_inline_type_behavior_be_blocked(&element, type_, source)
+                    .0
+            })
+            .unwrap_or(csp::CheckResult::Allowed)
+    }
+
     /// Prevent any JS or layout from running until the corresponding call to
     /// `remove_script_and_layout_blocker`. Used to isolate periods in which
     /// the DOM is in an unstable state and should not be exposed to arbitrary

components/script/dom/document.rs

@@ -38,6 +38,7 @@ use crate::task_source::websocket::WebsocketTaskSource;
 use crate::task_source::TaskSourceName;
 use crate::timers::{IsInterval, OneshotTimerCallback, OneshotTimerHandle};
 use crate::timers::{OneshotTimers, TimerCallback};
+use content_security_policy::CspList;
 use devtools_traits::{ScriptToDevtoolsControlMsg, WorkerId};
 use dom_struct::dom_struct;
 use ipc_channel::ipc::IpcSender;
@@ -812,6 +813,15 @@ impl GlobalScope {
     pub fn get_user_agent(&self) -> Cow<'static, str> {
         self.user_agent.clone()
     }
+
+    /// https://www.w3.org/TR/CSP/#get-csp-of-object
+    pub fn get_csp_list(&self) -> Option<CspList> {
+        if let Some(window) = self.downcast::<Window>() {
+            return window.Document().get_csp_list().map(|c| c.clone());
+        }
+        // TODO: Worker and Worklet global scopes.
+        None
+    }
 }
 
 fn timestamp_in_ms(time: Timespec) -> u64 {