Corrections for limited duration licenses

[ Merge of http://go/wvgerrit/74627 ]

Limited duration licenses (where license duration is unlimited and
playback window is set to a small value) did not work correctly when
the initial decrypt call occured before the license was received.

Bug: 109653883
Test: WV unit/integration tests
Change-Id: I0738e97db525b239455e2ac93ab0bedd6611b311

libwvdrmengine/cdm/core/include/policy_engine.h

@@ -68,7 +68,7 @@ class PolicyEngine {
   virtual void SetLicenseForRelease(const video_widevine::License& license);
 
   // Call this on first decrypt to set the start of playback.
-  virtual void BeginDecryption(void);
+  virtual bool BeginDecryption(void);
   virtual void DecryptionEvent(void);
 
   // UpdateLicense is used in handling a license response for a renewal request.

libwvdrmengine/cdm/core/src/cdm_session.cpp

@@ -640,8 +640,7 @@ CdmResponseType CdmSession::Decrypt(const CdmDecryptionParameters& params) {
 
   if (status == NO_ERROR) {
     if (is_initial_decryption_) {
-      policy_engine_->BeginDecryption();
-      is_initial_decryption_ = false;
+      is_initial_decryption_ = !policy_engine_->BeginDecryption();
     }
     has_decrypted_since_last_report_ = true;
     if (!is_usage_update_needed_) {

libwvdrmengine/cdm/core/src/policy_engine.cpp

@@ -231,7 +231,7 @@ void PolicyEngine::UpdateLicense(const License& license) {
   NotifyExpirationUpdate(current_time);
 }
 
-void PolicyEngine::BeginDecryption() {
+bool PolicyEngine::BeginDecryption() {
   if (playback_start_time_ == 0) {
     switch (license_state_) {
       case kLicenseStateCanPlay:
@@ -246,14 +246,17 @@ void PolicyEngine::BeginDecryption() {
           license_state_ = kLicenseStateNeedRenewal;
         }
         NotifyExpirationUpdate(playback_start_time_);
-        break;
+        return true;
       case kLicenseStateInitial:
       case kLicenseStatePending:
       case kLicenseStateExpired:
       default:
-        break;
+        return false;
     }
   }
+  else {
+    return true;
+  }
 }
 
 void PolicyEngine::DecryptionEvent() { last_playback_time_ = GetCurrentTime(); }

libwvdrmengine/cdm/core/test/policy_engine_unittest.cpp

@@ -819,6 +819,40 @@ TEST_F(PolicyEngineTest, PlaybackOk_RentalAndLicense0_WithPlayback) {
   EXPECT_FALSE(policy_engine_->CanDecryptContent(kSomeRandomKeyId));
 }
 
+TEST_F(PolicyEngineTest,
+       PlaybackOk_RentalAndLicense0_WithPlaybackBeforeLicense) {
+  License_Policy* policy = license_.mutable_policy();
+  policy->clear_license_duration_seconds();
+  policy->clear_rental_duration_seconds();
+  // Only |playback_duration_seconds| set.
+
+  policy_engine_->BeginDecryption();
+
+  EXPECT_CALL(*mock_clock_, GetCurrentTime())
+      .WillOnce(Return(kLicenseStartTime + 1))
+      .WillOnce(Return(kPlaybackStartTime))
+      .WillOnce(Return(kPlaybackStartTime + kPlaybackDuration - 10))
+      .WillOnce(Return(kPlaybackStartTime + kPlaybackDuration + 10));
+
+  ExpectSessionKeysChange(kKeyStatusExpired, false);
+  ExpectSessionKeysChange(kKeyStatusUsable, true);
+  EXPECT_CALL(mock_event_listener_, OnExpirationUpdate(_, 0));
+  EXPECT_CALL(mock_event_listener_,
+              OnExpirationUpdate(_, kPlaybackStartTime + kPlaybackDuration));
+
+  policy_engine_->SetLicense(license_);
+  policy_engine_->BeginDecryption();
+  policy_engine_->OnTimerEvent();
+
+  EXPECT_TRUE(policy_engine_->CanDecryptContent(kKeyId));
+  EXPECT_FALSE(policy_engine_->CanDecryptContent(kSomeRandomKeyId));
+
+  policy_engine_->OnTimerEvent();
+
+  EXPECT_FALSE(policy_engine_->CanDecryptContent(kKeyId));
+  EXPECT_FALSE(policy_engine_->CanDecryptContent(kSomeRandomKeyId));
+}
+
 TEST_F(PolicyEngineTest, PlaybackOk_Durations0) {
   License_Policy* policy = license_.mutable_policy();
   policy->set_rental_duration_seconds(kDurationUnlimited);

libwvdrmengine/cdm/test/request_license_test.cpp

@@ -520,6 +520,16 @@ std::string kPsshStreamingClip7 = wvcdm::a2bs_hex(
     "EDEF8BA979D64ACEA3C827DCD51D21ED00000022"  // Widevine system id
     "08011a0d7769646576696e655f74657374220f73"  // pssh data
     "747265616d696e675f636c697037");
+std::string kPsshStreamingClip20 = wvcdm::a2bs_hex(
+    "000000437073736800000000"                  // blob size and pssh
+    "EDEF8BA979D64ACEA3C827DCD51D21ED00000023"  // Widevine system id
+    "08011a0d7769646576696e655f746573"          // pssh data
+    "74221073747265616d696e675f636c69703230");
+std::string kPsshStreamingClip21 = wvcdm::a2bs_hex(
+    "000000437073736800000000"                  // blob size and pssh
+    "EDEF8BA979D64ACEA3C827DCD51D21ED00000023"  // Widevine system id
+    "08011a0d7769646576696e655f746573"          // pssh data
+    "74221073747265616d696e675f636c69703231");
 
 std::string kProviderSessionTokenStreamingClip3 = wvcdm::a2bs_hex(
     "4851305A4A4156485A554936444E4931");
@@ -527,6 +537,15 @@ std::string kProviderSessionTokenStreamingClip4 = wvcdm::a2bs_hex(
     "4942524F4355544E5557553145463243");
 std::string kProviderSessionTokenStreamingClip7 = wvcdm::a2bs_hex(
     "44434C53524F4E30394C4E5535544B4C");
+std::string kProviderSessionTokenStreamingClip20 = wvcdm::a2bs_hex(
+    "4851305A4A4156485A554936444E4931");
+std::string kProviderSessionTokenStreamingClip21 = wvcdm::a2bs_hex(
+    "4851305A4A4156485A554936444E4931");
+
+// playback duration is 10 seconds+uncertainty window
+const std::chrono::milliseconds
+    kExpirationStreamingClip21PlaybackDurationTimeMs =
+        std::chrono::milliseconds(12*1000);
 
 UsageLicenseAndSubSampleInfo kUsageLicenseTestVector1[] = {
     { kPsshStreamingClip3, &usage_info_sub_samples_icp[0],
@@ -1634,6 +1653,12 @@ class WvCdmRequestLicenseTest : public WvCdmTestBase {
 
   bool VerifyDecryption(const CdmSessionId& session_id,
                         const SubSampleInfo& data) {
+    return VerifyDecryption(session_id, data, NO_ERROR);
+  }
+
+  bool VerifyDecryption(const CdmSessionId& session_id,
+                        const SubSampleInfo& data,
+                        CdmResponseType expected_response) {
     std::vector<uint8_t> decrypt_buffer(data.encrypt_data.size());
     CdmDecryptionParameters decryption_parameters(
         &data.key_id, &data.encrypt_data.front(), data.encrypt_data.size(),
@@ -1644,7 +1669,7 @@ class WvCdmRequestLicenseTest : public WvCdmTestBase {
     CdmResponseType status = decryptor_.Decrypt(session_id,
                                                 data.validate_key_id,
                                                 decryption_parameters);
-    EXPECT_EQ(NO_ERROR, status);
+    EXPECT_EQ(expected_response, status);
     if (status != NO_ERROR)
       return false;
 
@@ -4981,6 +5006,70 @@ TEST_F(WvCdmRequestLicenseTest, DecryptionKeyExpiredTest) {
   decryptor_.CloseSession(session_id_);
 }
 
+TEST_F(WvCdmRequestLicenseTest, PlaybackExpiry) {
+  StrictMock<TestWvCdmEventListener> listener;
+  DecryptCallbackTester decrypt_callback(
+      &decryptor_,
+      &usage_info_sub_samples_icp[0]);
+  decryptor_.OpenSession(config_.key_system(), NULL, kDefaultCdmIdentifier,
+                         &listener, &session_id_);
+
+  EXPECT_CALL(
+      listener,
+      OnSessionKeysChange(
+          session_id_,
+          AllOf(Each(Pair(_, kKeyStatusUsable)), Not(IsEmpty())), true))
+      .WillOnce(Invoke(&decrypt_callback, &DecryptCallbackTester::Decrypt));
+  EXPECT_CALL(listener, OnExpirationUpdate(session_id_, _));
+
+  GenerateKeyRequest(kPsshStreamingClip21, kLicenseTypeStreaming, NULL);
+  VerifyKeyRequestResponse(config_.license_server(), config_.client_auth());
+
+  EXPECT_CALL(
+      listener,
+      OnSessionKeysChange(
+          session_id_,
+          AllOf(Each(Pair(_, kKeyStatusExpired)), Not(IsEmpty())), false));
+
+  // Elapse time so that the key should now be considered expired.
+  std::this_thread::sleep_for(kExpirationStreamingClip21PlaybackDurationTimeMs);
+}
+
+TEST_F(WvCdmRequestLicenseTest, PlaybackExpiry_DecryptBeforeLicense) {
+  StrictMock<TestWvCdmEventListener> listener;
+  DecryptCallbackTester decrypt_callback(
+      &decryptor_,
+      &usage_info_sub_samples_icp[0]);
+  decryptor_.OpenSession(config_.key_system(), NULL, kDefaultCdmIdentifier,
+                         &listener, &session_id_);
+
+  // Decrypt before license is received is expected to fail but should
+  // not start the playback timer
+  EXPECT_FALSE(VerifyDecryption(session_id_,
+                                usage_info_sub_samples_icp[0], NEED_KEY));
+  std::this_thread::sleep_for(kExpirationStreamingClip21PlaybackDurationTimeMs);
+
+  EXPECT_CALL(
+      listener,
+      OnSessionKeysChange(
+          session_id_,
+          AllOf(Each(Pair(_, kKeyStatusUsable)), Not(IsEmpty())), true))
+      .WillOnce(Invoke(&decrypt_callback, &DecryptCallbackTester::Decrypt));
+  EXPECT_CALL(listener, OnExpirationUpdate(session_id_, _));
+
+  GenerateKeyRequest(kPsshStreamingClip21, kLicenseTypeStreaming, NULL);
+  VerifyKeyRequestResponse(config_.license_server(), config_.client_auth());
+
+  EXPECT_CALL(
+      listener,
+      OnSessionKeysChange(
+          session_id_,
+          AllOf(Each(Pair(_, kKeyStatusExpired)), Not(IsEmpty())), false));
+
+  // Elapse time so that the key should now be considered expired.
+  std::this_thread::sleep_for(kExpirationStreamingClip21PlaybackDurationTimeMs);
+}
+
 TEST_F(WvCdmRequestLicenseTest, SessionKeyChangeNotificationTest) {
   StrictMock<TestWvCdmEventListener> listener;
   DecryptCallbackTester decrypt_callback(