Bug 1756500 - Implement key verification for origin trials. r=keeler,nkulatova

Somewhat straight-forward. Add a test key so that we can add some tests
for this.

Differential Revision: https://phabricator.services.mozilla.com/D139402

dom/crypto/CryptoKey.cpp

@@ -862,7 +862,7 @@ nsresult CryptoKey::PrivateKeyToJwk(SECKEYPrivateKey* aPrivKey,
 }
 
 UniqueSECKEYPublicKey CreateECPublicKey(const SECItem* aKeyData,
-                                        const nsString& aNamedCurve) {
+                                        const nsAString& aNamedCurve) {
   UniquePLArenaPool arena(PORT_NewArena(DER_DEFAULT_CHUNKSIZE));
   if (!arena) {
     return nullptr;

dom/crypto/WebCryptoCommon.h

@@ -27,6 +27,7 @@
 #include "secitem.h"
 #include "secoid.h"
 #include "secoidt.h"
+#include "ScopedNSSTypes.h"
 
 struct JSStructuredCloneReader;
 struct JSStructuredCloneWriter;
@@ -128,8 +129,7 @@ const SECItem SEC_OID_DATA_EC_DH = {
     siBuffer, (unsigned char*)id_ecDH,
     static_cast<unsigned int>(mozilla::ArrayLength(id_ecDH))};
 
-namespace mozilla {
-namespace dom {
+namespace mozilla::dom {
 
 inline bool ReadBuffer(JSStructuredCloneReader* aReader,
                        CryptoBuffer& aBuffer) {
@@ -273,7 +273,7 @@ inline bool CheckEncodedECParameters(const SECItem* aEcParams) {
   return true;
 }
 
-inline SECItem* CreateECParamsForCurve(const nsString& aNamedCurve,
+inline SECItem* CreateECParamsForCurve(const nsAString& aNamedCurve,
                                        PLArenaPool* aArena) {
   MOZ_ASSERT(aArena);
   SECOidTag curveOIDTag;
@@ -313,7 +313,10 @@ inline SECItem* CreateECParamsForCurve(const nsString& aNamedCurve,
   return params;
 }
 
-}  // namespace dom
-}  // namespace mozilla
+// Implemented in CryptoKey.cpp
+UniqueSECKEYPublicKey CreateECPublicKey(const SECItem* aKeyData,
+                                        const nsAString& aNamedCurve);
+
+}  // namespace mozilla::dom
 
 #endif  // mozilla_dom_WebCryptoCommon_h

dom/origin-trials/OriginTrials.cpp

@@ -16,37 +16,107 @@
 #include "js/Wrapper.h"
 #include "nsGlobalWindowInner.h"
 #include "mozilla/dom/Document.h"
+#include "mozilla/dom/WebCryptoCommon.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "ScopedNSSTypes.h"
 
 namespace mozilla {
 
+LazyLogModule sOriginTrialsLog("OriginTrials");
+#define LOG(...) MOZ_LOG(sOriginTrialsLog, LogLevel::Debug, (__VA_ARGS__))
+
+// This is the EcdsaP256 public key from this key pair:
+//
+//  * https://github.com/emilio/origin-trial-token/blob/64f03749e2e8c58f811f67044cecc7d6955fd51a/tools/test-keys/test-ecdsa.pkcs8
+//  * https://github.com/emilio/origin-trial-token/blob/64f03749e2e8c58f811f67044cecc7d6955fd51a/tools/test-keys/test-ecdsa.pub
+//
+// See that repo for tools for key and token generation and signing.
+static const unsigned char kTestKey[65] = {
+    0x4,  0x4a, 0xae, 0x76, 0x64, 0x24, 0xa0, 0x55, 0xc4, 0x66, 0xe,
+    0x43, 0x32, 0x4c, 0x1d, 0x85, 0x8,  0x63, 0x6a, 0x93, 0xd4, 0x1d,
+    0xf,  0xfc, 0xb4, 0x2c, 0x77, 0x3d, 0xe6, 0x87, 0xdc, 0xeb, 0x46,
+    0xcd, 0xcf, 0x88, 0xd0, 0xe3, 0x39, 0x8f, 0xe5, 0x17, 0xb8, 0xc8,
+    0xd7, 0xd3, 0xdc, 0x32, 0x7c, 0x4f, 0x8,  0x8b, 0x61, 0x19, 0xdd,
+    0xc0, 0x2,  0x5f, 0x11, 0x20, 0x6b, 0x44, 0xcf, 0x2a, 0x64,
+};
+
+constexpr auto kEcAlgorithm =
+    NS_LITERAL_STRING_FROM_CSTRING(WEBCRYPTO_NAMED_CURVE_P256);
+
 bool VerifySignature(const uint8_t* aSignature, uintptr_t aSignatureLen,
                      const uint8_t* aData, uintptr_t aDataLen,
                      void* aUserData) {
   MOZ_RELEASE_ASSERT(aSignatureLen == 64);
+  LOG("VerifySignature()\n");
+
+  if (!StaticPrefs::dom_origin_trials_test_key_enabled()) {
     // TODO(emilio): Implement.
     return false;
+  }
+
+  const SECItem rawKey{siBuffer, const_cast<unsigned char*>(kTestKey),
+                       sizeof(kTestKey)};
+  MOZ_RELEASE_ASSERT(rawKey.data[0] == EC_POINT_FORM_UNCOMPRESSED);
+  UniqueSECKEYPublicKey pubKey = dom::CreateECPublicKey(&rawKey, kEcAlgorithm);
+  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.get(), 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 || aIsSubdomain || aIsUsageSubset) {
     // TODO(emilio): Support third-party tokens and so on.
     return false;
   }
 
   auto* principal = static_cast<nsIPrincipal*>(aUserData);
-  nsDependentCSubstring origin(reinterpret_cast<const char*>(aOrigin),
-                               aOriginLen);
   nsCOMPtr<nsIURI> originURI;
   if (NS_WARN_IF(NS_FAILED(NS_NewURI(getter_AddRefs(originURI), origin)))) {
     return false;
   }
 
-  return principal->IsSameOrigin(originURI);
+  if (NS_WARN_IF(!principal->IsSameOrigin(originURI))) {
+    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))) {
@@ -61,10 +131,12 @@ void OriginTrials::UpdateFromToken(const nsAString& aBase64EncodedToken,
   };
   auto result = origin_trials_ffi::origin_trials_parse_and_validate_token(
       decodedTokenSpan.data(), decodedTokenSpan.size(), &params);
-  if (!result.IsOk()) {
+  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;
 }
 
@@ -73,6 +145,7 @@ bool OriginTrials::IsEnabled(JSContext* aCx, JSObject* aObject,
   if (nsContentUtils::ThreadsafeIsSystemCaller(aCx)) {
     return true;
   }
+  LOG("OriginTrials::IsEnabled(%d)\n", int(aTrial));
   if (NS_IsMainThread()) {
     if (auto* win = xpc::WindowGlobalOrNull(js::UncheckedUnwrap(aObject))) {
       if (dom::Document* doc = win->GetExtantDoc()) {
@@ -86,4 +159,6 @@ bool OriginTrials::IsEnabled(JSContext* aCx, JSObject* aObject,
   return false;
 }
 
+#undef LOG
+
 }  // namespace mozilla

modules/libpref/init/StaticPrefList.yaml

@@ -2873,6 +2873,18 @@
   value: true
   mirror: always
 
+# Whether origin trials are enabled.
+- name: dom.origin-trials.enabled
+  type: bool
+  value: true
+  mirror: always
+
+# Whether we use the test key to verify tokens.
+- name: dom.origin-trials.test-key.enabled
+  type: bool
+  value: true
+  mirror: always
+
 # Is support for Window.paintWorklet enabled?
 - name: dom.paintWorklet.enabled
   type: bool