1 files changed, 336 insertions, 0 deletions
diff --git a/dom/security/featurepolicy/FeaturePolicy.cpp b/dom/security/featurepolicy/FeaturePolicy.cpp
new file mode 100644
index 0000000000..07b6e9fba3
--- /dev/null
+++ b/dom/security/featurepolicy/FeaturePolicy.cpp
@@ -0,0 +1,336 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "FeaturePolicy.h"
+#include "mozilla/BasePrincipal.h"
+#include "mozilla/dom/Feature.h"
+#include "mozilla/dom/FeaturePolicyBinding.h"
+#include "mozilla/dom/FeaturePolicyParser.h"
+#include "mozilla/dom/FeaturePolicyUtils.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "nsContentUtils.h"
+#include "nsNetUtil.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(FeaturePolicy)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(FeaturePolicy)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(FeaturePolicy)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(FeaturePolicy)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+FeaturePolicy::FeaturePolicy(nsINode* aNode) : mParentNode(aNode) {}
+
+void FeaturePolicy::InheritPolicy(FeaturePolicy* aParentPolicy) {
+  MOZ_ASSERT(aParentPolicy);
+
+  mInheritedDeniedFeatureNames.Clear();
+
+  RefPtr<FeaturePolicy> dest = this;
+  RefPtr<FeaturePolicy> src = aParentPolicy;
+
+  // Inherit origins which explicitly declared policy in chain
+  for (const Feature& featureInChain :
+       aParentPolicy->mDeclaredFeaturesInAncestorChain) {
+    dest->AppendToDeclaredAllowInAncestorChain(featureInChain);
+  }
+
+  FeaturePolicyUtils::ForEachFeature([dest, src](const char* aFeatureName) {
+    nsString featureName;
+    featureName.AppendASCII(aFeatureName);
+    // Store unsafe allows all (allow=*)
+    if (src->HasFeatureUnsafeAllowsAll(featureName)) {
+      dest->mParentAllowedAllFeatures.AppendElement(featureName);
+    }
+
+    // If the destination has a declared feature (via the HTTP header or 'allow'
+    // attribute) we allow the feature if the destination allows it and the
+    // parent allows its origin or the destinations' one.
+    if (dest->HasDeclaredFeature(featureName) &&
+        dest->AllowsFeatureInternal(featureName, dest->mDefaultOrigin)) {
+      if (!src->AllowsFeatureInternal(featureName, src->mDefaultOrigin) &&
+          !src->AllowsFeatureInternal(featureName, dest->mDefaultOrigin)) {
+        dest->SetInheritedDeniedFeature(featureName);
+      }
+      return;
+    }
+
+    // If there was not a declared feature, we allow the feature if the parent
+    // FeaturePolicy allows the current origin.
+    if (!src->AllowsFeatureInternal(featureName, dest->mDefaultOrigin)) {
+      dest->SetInheritedDeniedFeature(featureName);
+    }
+  });
+}
+
+void FeaturePolicy::SetInheritedDeniedFeature(const nsAString& aFeatureName) {
+  MOZ_ASSERT(!HasInheritedDeniedFeature(aFeatureName));
+  mInheritedDeniedFeatureNames.AppendElement(aFeatureName);
+}
+
+bool FeaturePolicy::HasInheritedDeniedFeature(
+    const nsAString& aFeatureName) const {
+  return mInheritedDeniedFeatureNames.Contains(aFeatureName);
+}
+
+bool FeaturePolicy::HasDeclaredFeature(const nsAString& aFeatureName) const {
+  for (const Feature& feature : mFeatures) {
+    if (feature.Name().Equals(aFeatureName)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool FeaturePolicy::HasFeatureUnsafeAllowsAll(
+    const nsAString& aFeatureName) const {
+  for (const Feature& feature : mFeatures) {
+    if (feature.AllowsAll() && feature.Name().Equals(aFeatureName)) {
+      return true;
+    }
+  }
+
+  // We should look into parent too (for example, document of iframe which
+  // allows all, would be unsafe)
+  return mParentAllowedAllFeatures.Contains(aFeatureName);
+}
+
+void FeaturePolicy::AppendToDeclaredAllowInAncestorChain(
+    const Feature& aFeature) {
+  for (Feature& featureInChain : mDeclaredFeaturesInAncestorChain) {
+    if (featureInChain.Name().Equals(aFeature.Name())) {
+      MOZ_ASSERT(featureInChain.HasAllowList());
+
+      nsTArray<nsCOMPtr<nsIPrincipal>> list;
+      aFeature.GetAllowList(list);
+
+      for (nsIPrincipal* principal : list) {
+        featureInChain.AppendToAllowList(principal);
+      }
+      continue;
+    }
+  }
+
+  mDeclaredFeaturesInAncestorChain.AppendElement(aFeature);
+}
+
+bool FeaturePolicy::IsSameOriginAsSrc(nsIPrincipal* aPrincipal) const {
+  MOZ_ASSERT(aPrincipal);
+
+  if (!mSrcOrigin) {
+    return false;
+  }
+
+  return BasePrincipal::Cast(mSrcOrigin)
+      ->Subsumes(aPrincipal, BasePrincipal::ConsiderDocumentDomain);
+}
+
+void FeaturePolicy::SetDeclaredPolicy(Document* aDocument,
+                                      const nsAString& aPolicyString,
+                                      nsIPrincipal* aSelfOrigin,
+                                      nsIPrincipal* aSrcOrigin) {
+  ResetDeclaredPolicy();
+
+  mDeclaredString = aPolicyString;
+  mSelfOrigin = aSelfOrigin;
+  mSrcOrigin = aSrcOrigin;
+
+  Unused << NS_WARN_IF(!FeaturePolicyParser::ParseString(
+      aPolicyString, aDocument, aSelfOrigin, aSrcOrigin, mFeatures));
+
+  // Only store explicitly declared allowlist
+  for (const Feature& feature : mFeatures) {
+    if (feature.HasAllowList()) {
+      AppendToDeclaredAllowInAncestorChain(feature);
+    }
+  }
+}
+
+void FeaturePolicy::ResetDeclaredPolicy() {
+  mFeatures.Clear();
+  mDeclaredString.Truncate();
+  mSelfOrigin = nullptr;
+  mSrcOrigin = nullptr;
+  mDeclaredFeaturesInAncestorChain.Clear();
+  mAttributeEnabledFeatureNames.Clear();
+}
+
+JSObject* FeaturePolicy::WrapObject(JSContext* aCx,
+                                    JS::Handle<JSObject*> aGivenProto) {
+  return FeaturePolicy_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+bool FeaturePolicy::AllowsFeature(const nsAString& aFeatureName,
+                                  const Optional<nsAString>& aOrigin) const {
+  nsCOMPtr<nsIPrincipal> origin;
+  if (aOrigin.WasPassed()) {
+    nsCOMPtr<nsIURI> uri;
+    nsresult rv = NS_NewURI(getter_AddRefs(uri), aOrigin.Value());
+    if (NS_FAILED(rv)) {
+      return false;
+    }
+    origin = BasePrincipal::CreateContentPrincipal(
+        uri, BasePrincipal::Cast(mDefaultOrigin)->OriginAttributesRef());
+  } else {
+    origin = mDefaultOrigin;
+  }
+
+  if (NS_WARN_IF(!origin)) {
+    return false;
+  }
+
+  return AllowsFeatureInternal(aFeatureName, origin);
+}
+
+bool FeaturePolicy::AllowsFeatureExplicitlyInAncestorChain(
+    const nsAString& aFeatureName, nsIPrincipal* aOrigin) const {
+  MOZ_ASSERT(aOrigin);
+
+  for (const Feature& feature : mDeclaredFeaturesInAncestorChain) {
+    if (feature.Name().Equals(aFeatureName)) {
+      return feature.AllowListContains(aOrigin);
+    }
+  }
+
+  return false;
+}
+
+bool FeaturePolicy::AllowsFeatureInternal(const nsAString& aFeatureName,
+                                          nsIPrincipal* aOrigin) const {
+  MOZ_ASSERT(aOrigin);
+
+  // Let's see if have to disable this feature because inherited policy.
+  if (HasInheritedDeniedFeature(aFeatureName)) {
+    return false;
+  }
+
+  for (const Feature& feature : mFeatures) {
+    if (feature.Name().Equals(aFeatureName)) {
+      return feature.Allows(aOrigin);
+    }
+  }
+
+  switch (FeaturePolicyUtils::DefaultAllowListFeature(aFeatureName)) {
+    case FeaturePolicyUtils::FeaturePolicyValue::eAll:
+      return true;
+
+    case FeaturePolicyUtils::FeaturePolicyValue::eSelf:
+      return BasePrincipal::Cast(mDefaultOrigin)
+          ->Subsumes(aOrigin, BasePrincipal::ConsiderDocumentDomain);
+
+    case FeaturePolicyUtils::FeaturePolicyValue::eNone:
+      return false;
+
+    default:
+      MOZ_CRASH("Unknown default value");
+  }
+
+  return false;
+}
+
+void FeaturePolicy::Features(nsTArray<nsString>& aFeatures) {
+  RefPtr<FeaturePolicy> self = this;
+  FeaturePolicyUtils::ForEachFeature(
+      [self, &aFeatures](const char* aFeatureName) {
+        nsString featureName;
+        featureName.AppendASCII(aFeatureName);
+        aFeatures.AppendElement(featureName);
+      });
+}
+
+void FeaturePolicy::AllowedFeatures(nsTArray<nsString>& aAllowedFeatures) {
+  RefPtr<FeaturePolicy> self = this;
+  FeaturePolicyUtils::ForEachFeature(
+      [self, &aAllowedFeatures](const char* aFeatureName) {
+        nsString featureName;
+        featureName.AppendASCII(aFeatureName);
+
+        if (self->AllowsFeatureInternal(featureName, self->mDefaultOrigin)) {
+          aAllowedFeatures.AppendElement(featureName);
+        }
+      });
+}
+
+void FeaturePolicy::GetAllowlistForFeature(const nsAString& aFeatureName,
+                                           nsTArray<nsString>& aList) const {
+  if (!AllowsFeatureInternal(aFeatureName, mDefaultOrigin)) {
+    return;
+  }
+
+  for (const Feature& feature : mFeatures) {
+    if (feature.Name().Equals(aFeatureName)) {
+      if (feature.AllowsAll()) {
+        aList.AppendElement(u"*"_ns);
+        return;
+      }
+
+      nsTArray<nsCOMPtr<nsIPrincipal>> list;
+      feature.GetAllowList(list);
+
+      for (nsIPrincipal* principal : list) {
+        nsAutoCString originNoSuffix;
+        nsresult rv = principal->GetOriginNoSuffix(originNoSuffix);
+        if (NS_WARN_IF(NS_FAILED(rv))) {
+          return;
+        }
+
+        aList.AppendElement(NS_ConvertUTF8toUTF16(originNoSuffix));
+      }
+      return;
+    }
+  }
+
+  switch (FeaturePolicyUtils::DefaultAllowListFeature(aFeatureName)) {
+    case FeaturePolicyUtils::FeaturePolicyValue::eAll:
+      aList.AppendElement(u"*"_ns);
+      return;
+
+    case FeaturePolicyUtils::FeaturePolicyValue::eSelf: {
+      nsAutoCString originNoSuffix;
+      nsresult rv = mDefaultOrigin->GetOriginNoSuffix(originNoSuffix);
+      if (NS_WARN_IF(NS_FAILED(rv))) {
+        return;
+      }
+
+      aList.AppendElement(NS_ConvertUTF8toUTF16(originNoSuffix));
+      return;
+    }
+
+    case FeaturePolicyUtils::FeaturePolicyValue::eNone:
+      return;
+
+    default:
+      MOZ_CRASH("Unknown default value");
+  }
+}
+
+void FeaturePolicy::MaybeSetAllowedPolicy(const nsAString& aFeatureName) {
+  MOZ_ASSERT(FeaturePolicyUtils::IsSupportedFeature(aFeatureName) ||
+             FeaturePolicyUtils::IsExperimentalFeature(aFeatureName));
+  // Skip if feature is in experimental phase
+  if (!StaticPrefs::dom_security_featurePolicy_experimental_enabled() &&
+      FeaturePolicyUtils::IsExperimentalFeature(aFeatureName)) {
+    return;
+  }
+
+  if (HasDeclaredFeature(aFeatureName)) {
+    return;
+  }
+
+  Feature feature(aFeatureName);
+  feature.SetAllowsAll();
+
+  mFeatures.AppendElement(feature);
+  mAttributeEnabledFeatureNames.AppendElement(aFeatureName);
+}
+
+}  // namespace dom
+}  // namespace mozilla