1 files changed, 248 insertions, 0 deletions
diff --git a/dom/origin-trials/OriginTrials.cpp b/dom/origin-trials/OriginTrials.cpp
new file mode 100644
index 0000000000..9f9e6b44fe
--- /dev/null
+++ b/dom/origin-trials/OriginTrials.cpp
@@ -0,0 +1,248 @@
+/* -*- 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 "OriginTrials.h"
+#include "mozilla/Base64.h"
+#include "mozilla/Span.h"
+#include "nsString.h"
+#include "nsIPrincipal.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+#include "nsContentUtils.h"
+#include "xpcpublic.h"
+#include "jsapi.h"
+#include "js/Wrapper.h"
+#include "nsGlobalWindowInner.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/WorkerPrivate.h"
+#include "mozilla/dom/WorkletThread.h"
+#include "mozilla/dom/WebCryptoCommon.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "ScopedNSSTypes.h"
+#include <mutex>
+
+namespace mozilla {
+
+LazyLogModule sOriginTrialsLog("OriginTrials");
+#define LOG(...) MOZ_LOG(sOriginTrialsLog, LogLevel::Debug, (__VA_ARGS__))
+
+// prod.pub is the EcdsaP256 public key from the production key managed in
+// Google Cloud. See:
+//
+//   https://github.com/mozilla/origin-trial-token/blob/main/tools/README.md#get-the-public-key
+//
+// for how to get the public key.
+//
+// See also:
+//
+//   https://github.com/mozilla/origin-trial-token/blob/main/tools/README.md#sign-a-token-using-gcloud
+//
+// for how to sign using this key.
+//
+// test.pub is the EcdsaP256 public key from this key pair:
+//
+//  * https://github.com/mozilla/origin-trial-token/blob/64f03749e2e8c58f811f67044cecc7d6955fd51a/tools/test-keys/test-ecdsa.pkcs8
+//  * https://github.com/mozilla/origin-trial-token/blob/64f03749e2e8c58f811f67044cecc7d6955fd51a/tools/test-keys/test-ecdsa.pub
+//
+#include "keys.inc"
+
+constexpr auto kEcAlgorithm =
+    NS_LITERAL_STRING_FROM_CSTRING(WEBCRYPTO_NAMED_CURVE_P256);
+
+using RawKeyRef = Span<const unsigned char, sizeof(kProdKey)>;
+
+struct StaticCachedPublicKey {
+  constexpr StaticCachedPublicKey() = default;
+
+  SECKEYPublicKey* Get(const RawKeyRef aRawKey);
+
+ private:
+  std::once_flag mFlag;
+  UniqueSECKEYPublicKey mKey;
+};
+
+SECKEYPublicKey* StaticCachedPublicKey::Get(const RawKeyRef aRawKey) {
+  std::call_once(mFlag, [&] {
+    const SECItem item{siBuffer, const_cast<unsigned char*>(aRawKey.data()),
+                       unsigned(aRawKey.Length())};
+    MOZ_RELEASE_ASSERT(item.data[0] == EC_POINT_FORM_UNCOMPRESSED);
+    mKey = dom::CreateECPublicKey(&item, kEcAlgorithm);
+    if (mKey) {
+      // It's fine to capture [this] by pointer because we are always static.
+      if (NS_IsMainThread()) {
+        RunOnShutdown([this] { mKey = nullptr; });
+      } else {
+        NS_DispatchToMainThread(NS_NewRunnableFunction(
+            "ClearStaticCachedPublicKey",
+            [this] { RunOnShutdown([this] { mKey = nullptr; }); }));
+      }
+    }
+  });
+  return mKey.get();
+}
+
+bool VerifySignature(const uint8_t* aSignature, uintptr_t aSignatureLen,
+                     const uint8_t* aData, uintptr_t aDataLen,
+                     void* aUserData) {
+  MOZ_RELEASE_ASSERT(aSignatureLen == 64);
+  static StaticCachedPublicKey sTestKey;
+  static StaticCachedPublicKey sProdKey;
+
+  LOG("VerifySignature()\n");
+
+  SECKEYPublicKey* pubKey = StaticPrefs::dom_origin_trials_test_key_enabled()
+                                ? sTestKey.Get(Span(kTestKey))
+                                : sProdKey.Get(Span(kProdKey));
+  if (NS_WARN_IF(!pubKey)) {
+    LOG("  Failed to create public key?");
+    return false;
+  }
+
+  if (NS_WARN_IF(aDataLen > UINT_MAX)) {
+    LOG("  Way too large data.");
+    return false;
+  }
+
+  const SECItem signature{siBuffer, const_cast<unsigned char*>(aSignature),
+                          unsigned(aSignatureLen)};
+  const SECItem data{siBuffer, const_cast<unsigned char*>(aData),
+                     unsigned(aDataLen)};
+
+  // SEC_OID_ANSIX962_ECDSA_SHA256_SIGNATURE
+  const SECStatus result = PK11_VerifyWithMechanism(
+      pubKey, CKM_ECDSA_SHA256, nullptr, &signature, &data, nullptr);
+  if (NS_WARN_IF(result != SECSuccess)) {
+    LOG("  Failed to verify data.");
+    return false;
+  }
+  return true;
+}
+
+bool MatchesOrigin(const uint8_t* aOrigin, size_t aOriginLen, bool aIsSubdomain,
+                   bool aIsThirdParty, bool aIsUsageSubset, void* aUserData) {
+  const nsDependentCSubstring origin(reinterpret_cast<const char*>(aOrigin),
+                                     aOriginLen);
+
+  LOG("MatchesOrigin(%d, %d, %d, %s)\n", aIsThirdParty, aIsSubdomain,
+      aIsUsageSubset, nsCString(origin).get());
+
+  if (aIsThirdParty || aIsUsageSubset) {
+    // TODO(emilio): Support third-party tokens and so on.
+    return false;
+  }
+
+  auto* principal = static_cast<nsIPrincipal*>(aUserData);
+  nsCOMPtr<nsIURI> originURI;
+  if (NS_WARN_IF(NS_FAILED(NS_NewURI(getter_AddRefs(originURI), origin)))) {
+    return false;
+  }
+
+  const bool originMatches = [&] {
+    if (principal->IsSameOrigin(originURI)) {
+      return true;
+    }
+    if (aIsSubdomain) {
+      for (nsCOMPtr<nsIPrincipal> prin = principal->GetNextSubDomainPrincipal();
+           prin; prin = prin->GetNextSubDomainPrincipal()) {
+        if (prin->IsSameOrigin(originURI)) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }();
+
+  if (NS_WARN_IF(!originMatches)) {
+    LOG("Origin doesn't match\n");
+    return false;
+  }
+
+  return true;
+}
+
+void OriginTrials::UpdateFromToken(const nsAString& aBase64EncodedToken,
+                                   nsIPrincipal* aPrincipal) {
+  if (!StaticPrefs::dom_origin_trials_enabled()) {
+    return;
+  }
+
+  LOG("OriginTrials::UpdateFromToken()\n");
+
+  nsAutoCString decodedToken;
+  nsresult rv = mozilla::Base64Decode(aBase64EncodedToken, decodedToken);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return;
+  }
+
+  const Span<const uint8_t> decodedTokenSpan(decodedToken);
+  const origin_trials_ffi::OriginTrialValidationParams params{
+      VerifySignature,
+      MatchesOrigin,
+      /* user_data = */ aPrincipal,
+  };
+  auto result = origin_trials_ffi::origin_trials_parse_and_validate_token(
+      decodedTokenSpan.data(), decodedTokenSpan.size(), &params);
+  if (NS_WARN_IF(!result.IsOk())) {
+    LOG("  result = %d\n", int(result.tag));
+    return;  // TODO(emilio): Maybe report to console or what not?
+  }
+  OriginTrial trial = result.AsOk().trial;
+  LOG("  result = Ok(%d)\n", int(trial));
+  mEnabledTrials += trial;
+}
+
+OriginTrials OriginTrials::FromWindow(const nsGlobalWindowInner* aWindow) {
+  if (!aWindow) {
+    return {};
+  }
+  const dom::Document* doc = aWindow->GetExtantDoc();
+  if (!doc) {
+    return {};
+  }
+  return doc->Trials();
+}
+
+static int32_t PrefState(OriginTrial aTrial) {
+  switch (aTrial) {
+    case OriginTrial::TestTrial:
+      return StaticPrefs::dom_origin_trials_test_trial_state();
+    case OriginTrial::CoepCredentialless:
+      return StaticPrefs::dom_origin_trials_coep_credentialless_state();
+    case OriginTrial::MAX:
+      MOZ_ASSERT_UNREACHABLE("Unknown trial!");
+      break;
+  }
+  return 0;
+}
+
+bool OriginTrials::IsEnabled(OriginTrial aTrial) const {
+  switch (PrefState(aTrial)) {
+    case 1:
+      return true;
+    case 2:
+      return false;
+    default:
+      break;
+  }
+
+  return mEnabledTrials.contains(aTrial);
+}
+
+bool OriginTrials::IsEnabled(JSContext* aCx, JSObject* aObject,
+                             OriginTrial aTrial) {
+  if (nsContentUtils::ThreadsafeIsSystemCaller(aCx)) {
+    return true;
+  }
+  LOG("OriginTrials::IsEnabled(%d)\n", int(aTrial));
+  nsIGlobalObject* global = xpc::CurrentNativeGlobal(aCx);
+  MOZ_ASSERT(global);
+  return global && global->Trials().IsEnabled(aTrial);
+}
+
+#undef LOG
+
+}  // namespace mozilla