1 files changed, 495 insertions, 0 deletions
diff --git a/caps/ExpandedPrincipal.cpp b/caps/ExpandedPrincipal.cpp
new file mode 100644
index 0000000000..7d65fec614
--- /dev/null
+++ b/caps/ExpandedPrincipal.cpp
@@ -0,0 +1,495 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sw=2 et 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 "ExpandedPrincipal.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIObjectInputStream.h"
+#include "nsReadableUtils.h"
+#include "mozilla/Base64.h"
+#include "mozilla/extensions/WebExtensionPolicy.h"
+#include "mozilla/JSONWriter.h"
+
+#include "js/JSON.h"
+#include "ExpandedPrincipalJSONHandler.h"
+#include "SubsumedPrincipalJSONHandler.h"
+
+using namespace mozilla;
+
+NS_IMPL_CLASSINFO(ExpandedPrincipal, nullptr, 0, NS_EXPANDEDPRINCIPAL_CID)
+NS_IMPL_QUERY_INTERFACE_CI(ExpandedPrincipal, nsIPrincipal,
+                           nsIExpandedPrincipal)
+NS_IMPL_CI_INTERFACE_GETTER(ExpandedPrincipal, nsIPrincipal,
+                            nsIExpandedPrincipal)
+
+ExpandedPrincipal::ExpandedPrincipal(
+    nsTArray<nsCOMPtr<nsIPrincipal>>&& aPrincipals,
+    const nsACString& aOriginNoSuffix, const OriginAttributes& aAttrs)
+    : BasePrincipal(eExpandedPrincipal, aOriginNoSuffix, aAttrs),
+      mPrincipals(std::move(aPrincipals)) {}
+
+ExpandedPrincipal::~ExpandedPrincipal() = default;
+
+already_AddRefed<ExpandedPrincipal> ExpandedPrincipal::Create(
+    const nsTArray<nsCOMPtr<nsIPrincipal>>& aAllowList,
+    const OriginAttributes& aAttrs) {
+  nsTArray<nsCOMPtr<nsIPrincipal>> principals;
+  for (size_t i = 0; i < aAllowList.Length(); ++i) {
+    principals.AppendElement(aAllowList[i]);
+  }
+
+  nsAutoCString origin;
+  origin.AssignLiteral("[Expanded Principal [");
+  StringJoinAppend(
+      origin, ", "_ns, principals,
+      [](nsACString& dest, const nsCOMPtr<nsIPrincipal>& principal) {
+        nsAutoCString subOrigin;
+        DebugOnly<nsresult> rv = principal->GetOrigin(subOrigin);
+        MOZ_ASSERT(NS_SUCCEEDED(rv));
+        dest.Append(subOrigin);
+      });
+  origin.AppendLiteral("]]");
+
+  RefPtr<ExpandedPrincipal> ep =
+      new ExpandedPrincipal(std::move(principals), origin, aAttrs);
+  return ep.forget();
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::GetDomain(nsIURI** aDomain) {
+  *aDomain = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::SetDomain(nsIURI* aDomain) { return NS_OK; }
+
+bool ExpandedPrincipal::SubsumesInternal(
+    nsIPrincipal* aOther,
+    BasePrincipal::DocumentDomainConsideration aConsideration) {
+  // If aOther is an ExpandedPrincipal too, we break it down into its component
+  // nsIPrincipals, and check subsumes on each one.
+  if (Cast(aOther)->Is<ExpandedPrincipal>()) {
+    auto* expanded = Cast(aOther)->As<ExpandedPrincipal>();
+
+    for (auto& other : expanded->AllowList()) {
+      // Use SubsumesInternal rather than Subsumes here, since OriginAttribute
+      // checks are only done between non-expanded sub-principals, and we don't
+      // need to incur the extra virtual call overhead.
+      if (!SubsumesInternal(other, aConsideration)) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  // We're dealing with a regular principal. One of our principals must subsume
+  // it.
+  for (uint32_t i = 0; i < mPrincipals.Length(); ++i) {
+    if (Cast(mPrincipals[i])->Subsumes(aOther, aConsideration)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool ExpandedPrincipal::MayLoadInternal(nsIURI* uri) {
+  for (uint32_t i = 0; i < mPrincipals.Length(); ++i) {
+    if (BasePrincipal::Cast(mPrincipals[i])->MayLoadInternal(uri)) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+uint32_t ExpandedPrincipal::GetHashValue() {
+  MOZ_CRASH("extended principal should never be used as key in a hash map");
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::GetURI(nsIURI** aURI) {
+  *aURI = nullptr;
+  return NS_OK;
+}
+
+const nsTArray<nsCOMPtr<nsIPrincipal>>& ExpandedPrincipal::AllowList() {
+  return mPrincipals;
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::GetBaseDomain(nsACString& aBaseDomain) {
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::GetAddonId(nsAString& aAddonId) {
+  aAddonId.Truncate();
+  return NS_OK;
+};
+
+bool ExpandedPrincipal::AddonHasPermission(const nsAtom* aPerm) {
+  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
+    if (BasePrincipal::Cast(mPrincipals[i])->AddonHasPermission(aPerm)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool ExpandedPrincipal::AddonAllowsLoad(nsIURI* aURI,
+                                        bool aExplicit /* = false */) {
+  for (const auto& principal : mPrincipals) {
+    if (Cast(principal)->AddonAllowsLoad(aURI, aExplicit)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+void ExpandedPrincipal::SetCsp(nsIContentSecurityPolicy* aCSP) {
+  AssertIsOnMainThread();
+  mCSP = new nsMainThreadPtrHolder<nsIContentSecurityPolicy>(
+      "ExpandedPrincipal::mCSP", aCSP);
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::GetCsp(nsIContentSecurityPolicy** aCsp) {
+  AssertIsOnMainThread();
+  NS_IF_ADDREF(*aCsp = mCSP);
+  return NS_OK;
+}
+
+nsIPrincipal* ExpandedPrincipal::PrincipalToInherit(nsIURI* aRequestedURI) {
+  if (aRequestedURI) {
+    // If a given sub-principal subsumes the given URI, use that principal for
+    // inheritance. In general, this only happens with certain CORS modes, loads
+    // with forced principal inheritance, and creation of XML documents from
+    // XMLHttpRequests or fetch requests. For URIs that normally inherit a
+    // principal (such as data: URIs), we fall back to the last principal in the
+    // allowlist.
+    for (const auto& principal : mPrincipals) {
+      if (Cast(principal)->MayLoadInternal(aRequestedURI)) {
+        return principal;
+      }
+    }
+  }
+  return mPrincipals.LastElement();
+}
+
+nsresult ExpandedPrincipal::GetScriptLocation(nsACString& aStr) {
+  aStr.AssignLiteral("[Expanded Principal [");
+  for (size_t i = 0; i < mPrincipals.Length(); ++i) {
+    if (i != 0) {
+      aStr.AppendLiteral(", ");
+    }
+
+    nsAutoCString spec;
+    nsresult rv =
+        nsJSPrincipals::get(mPrincipals.ElementAt(i))->GetScriptLocation(spec);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aStr.Append(spec);
+  }
+  aStr.AppendLiteral("]]");
+  return NS_OK;
+}
+
+//////////////////////////////////////////
+// Methods implementing nsISerializable //
+//////////////////////////////////////////
+
+// We've had way too many issues with unversioned serializations, so
+// explicitly version this one.
+static const uint32_t kSerializationVersion = 1;
+
+NS_IMETHODIMP
+ExpandedPrincipal::Deserializer::Read(nsIObjectInputStream* aStream) {
+  uint32_t version;
+  nsresult rv = aStream->Read32(&version);
+  if (version != kSerializationVersion) {
+    MOZ_ASSERT(false,
+               "We really need to add handling of the old(?) version here");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  uint32_t count;
+  rv = aStream->Read32(&count);
+  if (NS_FAILED(rv)) {
+    return rv;
+  }
+
+  nsTArray<nsCOMPtr<nsIPrincipal>> principals;
+  if (!principals.SetCapacity(count, fallible)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  for (uint32_t i = 0; i < count; ++i) {
+    nsCOMPtr<nsISupports> read;
+    rv = aStream->ReadObject(true, getter_AddRefs(read));
+    if (NS_FAILED(rv)) {
+      return rv;
+    }
+
+    nsCOMPtr<nsIPrincipal> principal = do_QueryInterface(read);
+    if (!principal) {
+      return NS_ERROR_UNEXPECTED;
+    }
+
+    principals.AppendElement(std::move(principal));
+  }
+
+  mPrincipal = ExpandedPrincipal::Create(principals, OriginAttributes());
+  return NS_OK;
+}
+
+nsresult ExpandedPrincipal::GetSiteIdentifier(SiteIdentifier& aSite) {
+  // Call GetSiteIdentifier on each of our principals and return a new
+  // ExpandedPrincipal.
+
+  nsTArray<nsCOMPtr<nsIPrincipal>> allowlist;
+  for (const auto& principal : mPrincipals) {
+    SiteIdentifier site;
+    nsresult rv = Cast(principal)->GetSiteIdentifier(site);
+    NS_ENSURE_SUCCESS(rv, rv);
+    allowlist.AppendElement(site.GetPrincipal());
+  }
+
+  RefPtr<ExpandedPrincipal> expandedPrincipal =
+      ExpandedPrincipal::Create(allowlist, OriginAttributesRef());
+  MOZ_ASSERT(expandedPrincipal, "ExpandedPrincipal::Create returned nullptr?");
+
+  aSite.Init(expandedPrincipal);
+  return NS_OK;
+}
+
+nsresult ExpandedPrincipal::WriteJSONInnerProperties(JSONWriter& aWriter) {
+  aWriter.StartArrayProperty(JSONEnumKeyString<eSpecs>(),
+                             JSONWriter::CollectionStyle::SingleLineStyle);
+
+  for (const auto& principal : mPrincipals) {
+    aWriter.StartObjectElement(JSONWriter::CollectionStyle::SingleLineStyle);
+
+    nsresult rv = BasePrincipal::Cast(principal)->WriteJSONProperties(aWriter);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aWriter.EndObject();
+  }
+
+  aWriter.EndArray();
+
+  nsAutoCString suffix;
+  OriginAttributesRef().CreateSuffix(suffix);
+  if (suffix.Length() > 0) {
+    WriteJSONProperty<eSuffix>(aWriter, suffix);
+  }
+
+  return NS_OK;
+}
+
+bool ExpandedPrincipalJSONHandler::ProcessSubsumedResult(bool aResult) {
+  if (!aResult) {
+    NS_WARNING("Failed to parse subsumed principal");
+    mState = State::Error;
+    return false;
+  }
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::startObject() {
+  if (mSubsumedHandler.isSome()) {
+    return ProcessSubsumedResult(mSubsumedHandler->startObject());
+  }
+
+  switch (mState) {
+    case State::Init:
+      mState = State::StartObject;
+      break;
+    case State::StartArray:
+      mState = State::SubsumedPrincipal;
+      [[fallthrough]];
+    case State::SubsumedPrincipal:
+      mSubsumedHandler.emplace();
+
+      return ProcessSubsumedResult(mSubsumedHandler->startObject());
+    default:
+      NS_WARNING("Unexpected object value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::propertyName(const JS::Latin1Char* name,
+                                                size_t length) {
+  if (mSubsumedHandler.isSome()) {
+    return ProcessSubsumedResult(mSubsumedHandler->propertyName(name, length));
+  }
+
+  switch (mState) {
+    case State::StartObject:
+    case State::AfterPropertyValue: {
+      if (length != 1) {
+        NS_WARNING(
+            nsPrintfCString("Unexpected property name length: %zu", length)
+                .get());
+        mState = State::Error;
+        return false;
+      }
+
+      char key = char(name[0]);
+      switch (key) {
+        case ExpandedPrincipal::SpecsKey:
+          mState = State::SpecsKey;
+          break;
+        case ExpandedPrincipal::SuffixKey:
+          mState = State::SuffixKey;
+          break;
+        default:
+          NS_WARNING(
+              nsPrintfCString("Unexpected property name: '%c'", key).get());
+          mState = State::Error;
+          return false;
+      }
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected property name");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::endObject() {
+  if (mSubsumedHandler.isSome()) {
+    if (!ProcessSubsumedResult(mSubsumedHandler->endObject())) {
+      return false;
+    }
+    if (mSubsumedHandler->HasAccepted()) {
+      nsCOMPtr<nsIPrincipal> principal = mSubsumedHandler->mPrincipal.forget();
+      mSubsumedHandler.reset();
+      mAllowList.AppendElement(principal);
+    }
+    return true;
+  }
+
+  switch (mState) {
+    case State::AfterPropertyValue:
+      mPrincipal = ExpandedPrincipal::Create(mAllowList, mAttrs);
+      MOZ_ASSERT(mPrincipal);
+
+      mState = State::EndObject;
+      break;
+    default:
+      NS_WARNING("Unexpected end of object");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::startArray() {
+  switch (mState) {
+    case State::SpecsKey:
+      mState = State::StartArray;
+      break;
+    default:
+      NS_WARNING("Unexpected array value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::endArray() {
+  switch (mState) {
+    case State::SubsumedPrincipal: {
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected end of array");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+bool ExpandedPrincipalJSONHandler::stringValue(const JS::Latin1Char* str,
+                                               size_t length) {
+  if (mSubsumedHandler.isSome()) {
+    return ProcessSubsumedResult(mSubsumedHandler->stringValue(str, length));
+  }
+
+  switch (mState) {
+    case State::SpecsKey: {
+      nsDependentCSubstring specs(reinterpret_cast<const char*>(str), length);
+
+      for (const nsACString& each : specs.Split(',')) {
+        nsAutoCString result;
+        nsresult rv = Base64Decode(each, result);
+        MOZ_ASSERT(NS_SUCCEEDED(rv), "failed to decode");
+        if (NS_FAILED(rv)) {
+          mState = State::Error;
+          return false;
+        }
+
+        nsCOMPtr<nsIPrincipal> principal = BasePrincipal::FromJSON(result);
+        if (!principal) {
+          mState = State::Error;
+          return false;
+        }
+        mAllowList.AppendElement(principal);
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    case State::SuffixKey: {
+      nsDependentCSubstring attrs(reinterpret_cast<const char*>(str), length);
+      if (!mAttrs.PopulateFromSuffix(attrs)) {
+        mState = State::Error;
+        return false;
+      }
+
+      mState = State::AfterPropertyValue;
+      break;
+    }
+    default:
+      NS_WARNING("Unexpected string value");
+      mState = State::Error;
+      return false;
+  }
+
+  return true;
+}
+
+NS_IMETHODIMP
+ExpandedPrincipal::IsThirdPartyURI(nsIURI* aURI, bool* aRes) {
+  // ExpandedPrincipal for extension content scripts consist of two principals,
+  // the document's principal and the extension's principal.
+  // To make sure that the third-party check behaves like the web page on which
+  // the content script is running, ignore the extension's principal.
+
+  for (const auto& principal : mPrincipals) {
+    if (!Cast(principal)->AddonPolicyCore()) {
+      return Cast(principal)->IsThirdPartyURI(aURI, aRes);
+    }
+  }
+
+  if (mPrincipals.IsEmpty()) {
+    *aRes = true;
+    return NS_OK;
+  }
+
+  return Cast(mPrincipals[0])->IsThirdPartyURI(aURI, aRes);
+}