[Document Policy] Fix Document Policy lost issue in XSLT documents

This CL fixes the missing Document Policy issue for XSLT document.
The fix is similar to the previous fix on Permissions Policy.
See https://chromium-review.googlesource.com/c/chromium/src/+/2561144.

Bug: 1151954
Change-Id: Ie080c360ddc70ac46a63d5166b3830752ecdd94e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2563440
Commit-Queue: Charlie Hu <chenleihu@google.com>
Reviewed-by: Ian Clelland <iclelland@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833361}

third_party/blink/common/feature_policy/document_policy.cc

@@ -21,6 +21,21 @@ std::unique_ptr<DocumentPolicy> DocumentPolicy::CreateWithHeaderPolicy(
                                 header_policy.endpoint_map, feature_defaults);
 }
 
+// static
+std::unique_ptr<DocumentPolicy> DocumentPolicy::CopyStateFrom(
+    const DocumentPolicy* source) {
+  if (!source)
+    return nullptr;
+
+  std::unique_ptr<DocumentPolicy> new_policy =
+      DocumentPolicy::CreateWithHeaderPolicy(
+          {/* header_policy */ {}, /* endpoint_map */ {}});
+
+  new_policy->internal_feature_state_ = source->internal_feature_state_;
+  new_policy->endpoint_map_ = source->endpoint_map_;
+  return new_policy;
+}
+
 namespace {
 net::structured_headers::Item PolicyValueToItem(const PolicyValue& value) {
   switch (value.Type()) {

third_party/blink/public/common/feature_policy/document_policy.h

@@ -76,6 +76,8 @@ class BLINK_COMMON_EXPORT DocumentPolicy {
   static std::unique_ptr<DocumentPolicy> CreateWithHeaderPolicy(
       const ParsedDocumentPolicy& header_policy);
 
+  static std::unique_ptr<DocumentPolicy> CopyStateFrom(const DocumentPolicy*);
+
   // Returns true if the feature is unrestricted (has its default value for the
   // platform)
   bool IsFeatureEnabled(mojom::DocumentPolicyFeature feature) const;
@@ -131,9 +133,10 @@ class BLINK_COMMON_EXPORT DocumentPolicy {
   void UpdateFeatureState(const DocumentPolicyFeatureState& feature_state);
 
   // Internal feature state is represented as an array to avoid overhead
-  // in using container classes.
-  PolicyValue internal_feature_state_
-      [static_cast<size_t>(mojom::DocumentPolicyFeature::kMaxValue) + 1];
+  // of indexing into map like structure.
+  std::array<PolicyValue,
+             static_cast<size_t>(mojom::DocumentPolicyFeature::kMaxValue) + 1>
+      internal_feature_state_;
 
   FeatureEndpointMap endpoint_map_;
 

third_party/blink/renderer/core/execution_context/security_context_init.cc

@@ -273,4 +273,12 @@ void SecurityContextInit::InitFeaturePolicyFrom(const SecurityContext& other) {
   security_context.SetReportOnlyFeaturePolicy(
       FeaturePolicy::CopyStateFrom(other.GetReportOnlyFeaturePolicy()));
 }
+
+void SecurityContextInit::InitDocumentPolicyFrom(const SecurityContext& other) {
+  auto& security_context = execution_context_->GetSecurityContext();
+  security_context.SetDocumentPolicy(
+      DocumentPolicy::CopyStateFrom(other.GetDocumentPolicy()));
+  security_context.SetReportOnlyDocumentPolicy(
+      DocumentPolicy::CopyStateFrom(other.GetReportOnlyDocumentPolicy()));
+}
 }  // namespace blink

third_party/blink/renderer/core/execution_context/security_context_init.h

@@ -36,6 +36,13 @@ class CORE_EXPORT SecurityContextInit {
   // does not have header information available.
   void InitFeaturePolicyFrom(const SecurityContext& other);
 
+  // Init |document_policy_| and |report_only_document_policy_| by copying
+  // state from another security context instance.
+  // Used to carry document policy information from previous document
+  // to current document during XSLT navigation, because XSLT navigation
+  // does not have header information available.
+  void InitDocumentPolicyFrom(const SecurityContext& other);
+
   void ApplyFeaturePolicy(LocalFrame* frame,
                           const ResourceResponse& response,
                           const base::Optional<WebOriginPolicy>& origin_policy,

third_party/blink/renderer/core/loader/document_loader.cc

@@ -1688,23 +1688,23 @@ void DocumentLoader::CommitNavigation() {
 
   SecurityContextInit security_init(frame_->DomWindow());
 
-  // The document constructed by XSLTProcessor should inherit Feature Policy
-  // from the previous Document. Note: In XSLT commit, |response_| no longer
-  // holds header fields. Going through regular initialization will cause empty
-  // policy even if there is header on xml document.
-  // TODO(crbug.com/1151954): Fix the problem for Document Policy as well.
+  // The document constructed by XSLTProcessor should inherit Feature Policy and
+  // Document Policy from the previous Document. Note: In XSLT commit,
+  // |response_| no longer holds header fields. Going through regular
+  // initialization will cause empty policy even if there is header on xml
+  // document.
   if (commit_reason_ == CommitReason::kXSLT) {
     DCHECK(response_.HttpHeaderField(http_names::kFeaturePolicy).IsEmpty());
     DCHECK(response_.HttpHeaderField(http_names::kPermissionsPolicy).IsEmpty());
+    DCHECK(response_.HttpHeaderField(http_names::kDocumentPolicy).IsEmpty());
     security_init.InitFeaturePolicyFrom(previous_window->GetSecurityContext());
+    security_init.InitDocumentPolicyFrom(previous_window->GetSecurityContext());
   } else {
     // FeaturePolicy and DocumentPolicy require SecurityOrigin and origin trials
     // to be initialized.
     // TODO(iclelland): Add Feature-Policy-Report-Only to Origin Policy.
     security_init.ApplyFeaturePolicy(frame_.Get(), response_, origin_policy_,
                                      frame_policy_);
-  }
-
     // |document_policy_| is parsed in document loader because it is
     // compared with |frame_policy.required_document_policy| to decide
     // whether to block the document load or not.
@@ -1715,6 +1715,7 @@ void DocumentLoader::CommitNavigation() {
     security_init.ApplyDocumentPolicy(
         document_policy_,
         response_.HttpHeaderField(http_names::kDocumentPolicyReportOnly));
+  }
 
   navigation_scroll_allowed_ = !frame_->DomWindow()->IsFeatureEnabled(
       mojom::blink::DocumentPolicyFeature::kForceLoadAtTop);

third_party/blink/web_tests/http/tests/document-policy/document-policy-in-xsl.php

+<?php
+header("Document-Policy: oversized-images=2.0");
+header("Content-Type: application/xml");
+
+echo '<?xml version="1.0"?>
+<?xml-stylesheet href="resources/document-policy-in-xsl.xslt" type="text/xsl"?>
+<page>
+</page>';
+?>

third_party/blink/web_tests/http/tests/document-policy/document-policy-report-only-in-xsl.php

+<?php
+header("Document-Policy-Report-Only: oversized-images=2.0");
+header("Content-Type: application/xml");
+
+echo '<?xml version="1.0"?>
+<?xml-stylesheet href="resources/document-policy-report-only-in-xsl.xslt" type="text/xsl"?>
+<page>
+</page>';
+?>

third_party/blink/web_tests/http/tests/document-policy/resources/document-policy-in-xsl.xslt

+<?xml version="1.0"?>
+<xsl:stylesheet version="1.0"
+              xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+
+<xsl:template match="page">
+  <html>
+    <head>
+      <title> Test XSLT </title>
+      <script src="../../resources/testharness.js"></script>
+      <script src="../../resources/testharnessreport.js"></script>
+      <script>
+        // The page is expected to have 'oversized-images' threshold
+        // set to 2.0, i.e. images with actual_size / display_size ratio
+        // > 2.0 should be replaced with placeholder images. A violation
+        // report is also expected to be generated.
+
+        async_test(t => {
+          new ReportingObserver(t.step_func_done((reports, _) => {
+            assert_equals(reports.length, 1);
+            const report = reports[0];
+            assert_equals(report.type, 'document-policy-violation');
+            assert_equals(report.body.featureId, 'oversized-images');
+            assert_equals(report.body.disposition, 'enforce');
+          }), {types: ['document-policy-violation']}).observe();
+        });
+
+      </script>
+    </head>
+    <body bgcolor="#ffffff">
+      <img src="resources/green-256x256.jpg" width="100"></img>
+    </body>
+  </html>
+</xsl:template>
+
+</xsl:stylesheet>
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third_party/blink/web_tests/http/tests/document-policy/resources/document-policy-report-only-in-xsl.xslt

+<?xml version="1.0"?>
+<xsl:stylesheet version="1.0"
+              xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
+
+<xsl:template match="page">
+  <html>
+    <head>
+      <title> Test XSLT </title>
+      <script src="../../resources/testharness.js"></script>
+      <script src="../../resources/testharnessreport.js"></script>
+      <script>
+        // The page is expected to have 'oversized-images' threshold
+        // set to 2.0 in report only mode, i.e. images with
+        // actual_size / display_size ratio > 2.0 should generate
+        // violation reports.
+
+        async_test(t => {
+          new ReportingObserver(t.step_func_done((reports, _) => {
+            assert_equals(reports.length, 1);
+            const report = reports[0];
+            assert_equals(report.type, 'document-policy-violation');
+            assert_equals(report.body.featureId, 'oversized-images');
+            assert_equals(report.body.disposition, 'report');
+          }), {types: ['document-policy-violation']}).observe();
+        });
+
+      </script>
+    </head>
+    <body bgcolor="#ffffff">
+      <img src="resources/green-256x256.jpg" width="100"></img>
+    </body>
+  </html>
+</xsl:template>
+
+</xsl:stylesheet>
\ No newline at end of file