Double key image cache by requesting origin, and store CORS status with cached images.

components/net_traits/image/base.rs

@@ -2,6 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use crate::image_cache::CorsStatus;
 use ipc_channel::ipc::IpcSharedMemory;
 use piston_image::{DynamicImage, ImageFormat};
 use pixels::PixelFormat;
@@ -16,6 +17,7 @@ pub struct Image {
     pub bytes: IpcSharedMemory,
     #[ignore_malloc_size_of = "Defined in webrender_api"]
     pub id: Option<webrender_api::ImageKey>,
+    pub cors_status: CorsStatus,
 }
 
 impl fmt::Debug for Image {
@@ -37,7 +39,7 @@ pub struct ImageMetadata {
 // FIXME: Images must not be copied every frame. Instead we should atomically
 // reference count them.
 
-pub fn load_from_memory(buffer: &[u8]) -> Option<Image> {
+pub fn load_from_memory(buffer: &[u8], cors_status: CorsStatus) -> Option<Image> {
     if buffer.is_empty() {
         return None;
     }
@@ -61,6 +63,7 @@ pub fn load_from_memory(buffer: &[u8]) -> Option<Image> {
                     format: PixelFormat::BGRA8,
                     bytes: IpcSharedMemory::from_bytes(&*rgba),
                     id: None,
+                    cors_status,
                 })
             },
             Err(e) => {

components/net_traits/image_cache.rs

@@ -5,7 +5,7 @@
 use crate::image::base::{Image, ImageMetadata};
 use crate::FetchResponseMsg;
 use ipc_channel::ipc::IpcSender;
-use servo_url::ServoUrl;
+use servo_url::{ImmutableOrigin, ServoUrl};
 use std::sync::Arc;
 
 // ======================================================================
@@ -110,6 +110,7 @@ pub trait ImageCache: Sync + Send {
     fn find_image_or_metadata(
         &self,
         url: ServoUrl,
+        origin: ImmutableOrigin,
         use_placeholder: UsePlaceholder,
         can_request: CanRequestImages,
     ) -> Result<ImageOrMetadataAvailable, ImageState>;
@@ -121,3 +122,14 @@ pub trait ImageCache: Sync + Send {
     /// Inform the image cache about a response for a pending request.
     fn notify_pending_response(&self, id: PendingImageId, action: FetchResponseMsg);
 }
+
+/// Whether this response passed any CORS checks, and is thus safe to read from
+/// in cross-origin environments.
+#[derive(Clone, Copy, Debug, Deserialize, MallocSizeOf, PartialEq, Serialize)]
+pub enum CorsStatus {
+    /// The response is either same-origin or cross-origin but passed CORS checks.
+    Safe,
+    /// The response is cross-origin and did not pass CORS checks. It is unsafe
+    /// to expose pixel data to the requesting environment.
+    Unsafe,
+}