diff --git a/identity/support/src/IdentityCredentialSupport.cpp b/identity/support/src/IdentityCredentialSupport.cpp
index 4547624..7f4674d 100644
--- a/identity/support/src/IdentityCredentialSupport.cpp
+++ b/identity/support/src/IdentityCredentialSupport.cpp
@@ -644,7 +644,7 @@
     // the VTS tests. Of course, this is a pretend-only game since hopefully no
     // relying party is ever going to trust our batch key and those keys above
     // it.
-    ::keymaster::PureSoftKeymasterContext context(::keymaster::KmVersion::KEYMASTER_4_1,
+    ::keymaster::PureSoftKeymasterContext context(::keymaster::KmVersion::KEYMINT_1,
                                                   KM_SECURITY_LEVEL_TRUSTED_ENVIRONMENT);
 
     keymaster_error_t error;
@@ -682,10 +682,9 @@
 
     i2d_X509_NAME(subjectName.get(), &subjectPtr);
 
-    uint64_t nowMilliSeconds = time(nullptr) * 1000;
     ::keymaster::AuthorizationSet auth_set(
             ::keymaster::AuthorizationSetBuilder()
-                    .Authorization(::keymaster::TAG_CERTIFICATE_NOT_BEFORE, nowMilliSeconds)
+                    .Authorization(::keymaster::TAG_CERTIFICATE_NOT_BEFORE, activeTimeMilliSeconds)
                     .Authorization(::keymaster::TAG_CERTIFICATE_NOT_AFTER, expireTimeMilliSeconds)
                     .Authorization(::keymaster::TAG_ATTESTATION_CHALLENGE, challenge.data(),
                                    challenge.size())
diff --git a/neuralnetworks/aidl/vts/functional/CompilationCachingTests.cpp b/neuralnetworks/aidl/vts/functional/CompilationCachingTests.cpp
index e0b529f..94ce5c1 100644
--- a/neuralnetworks/aidl/vts/functional/CompilationCachingTests.cpp
+++ b/neuralnetworks/aidl/vts/functional/CompilationCachingTests.cpp
@@ -357,16 +357,40 @@
         return false;
     }
 
+    // If fallbackModel is not provided, call prepareModelFromCache.
+    // If fallbackModel is provided, and prepareModelFromCache returns GENERAL_FAILURE,
+    // then prepareModel(fallbackModel) will be called.
+    // This replicates the behaviour of the runtime when loading a model from cache.
+    // NNAPI Shim depends on this behaviour and may try to load the model from cache in
+    // prepareModel (shim needs model information when loading from cache).
     void prepareModelFromCache(const std::vector<ndk::ScopedFileDescriptor>& modelCache,
                                const std::vector<ndk::ScopedFileDescriptor>& dataCache,
-                               std::shared_ptr<IPreparedModel>* preparedModel,
-                               ErrorStatus* status) {
+                               std::shared_ptr<IPreparedModel>* preparedModel, ErrorStatus* status,
+                               const Model* fallbackModel = nullptr) {
         // Launch prepare model from cache.
         std::shared_ptr<PreparedModelCallback> preparedModelCallback =
                 ndk::SharedRefBase::make<PreparedModelCallback>();
         std::vector<uint8_t> cacheToken(std::begin(mToken), std::end(mToken));
-        const auto prepareLaunchStatus = kDevice->prepareModelFromCache(
+        auto prepareLaunchStatus = kDevice->prepareModelFromCache(
                 kNoDeadline, modelCache, dataCache, cacheToken, preparedModelCallback);
+
+        // The shim does not support prepareModelFromCache() properly, but it
+        // will still attempt to create a model from cache when modelCache or
+        // dataCache is provided in prepareModel(). Instead of failing straight
+        // away, we try to utilize that other code path when fallbackModel is
+        // set. Note that we cannot verify whether the returned model was
+        // actually prepared from cache in that case.
+        if (!prepareLaunchStatus.isOk() &&
+            prepareLaunchStatus.getExceptionCode() == EX_SERVICE_SPECIFIC &&
+            static_cast<ErrorStatus>(prepareLaunchStatus.getServiceSpecificError()) ==
+                    ErrorStatus::GENERAL_FAILURE &&
+            mIsCachingSupported && fallbackModel != nullptr) {
+            preparedModelCallback = ndk::SharedRefBase::make<PreparedModelCallback>();
+            prepareLaunchStatus = kDevice->prepareModel(
+                    *fallbackModel, ExecutionPreference::FAST_SINGLE_ANSWER, kDefaultPriority,
+                    kNoDeadline, modelCache, dataCache, cacheToken, preparedModelCallback);
+        }
+
         ASSERT_TRUE(prepareLaunchStatus.isOk() ||
                     prepareLaunchStatus.getExceptionCode() == EX_SERVICE_SPECIFIC)
                 << "prepareLaunchStatus: " << prepareLaunchStatus.getDescription();
@@ -382,6 +406,42 @@
         *preparedModel = preparedModelCallback->getPreparedModel();
     }
 
+    // Replicate behaviour of runtime when loading model from cache.
+    // Test if prepareModelFromCache behaves correctly when faced with bad
+    // arguments. If prepareModelFromCache is not supported (GENERAL_FAILURE),
+    // it attempts to call prepareModel with same arguments, which is expected either
+    // to not support the model (GENERAL_FAILURE) or return a valid model.
+    void verifyModelPreparationBehaviour(const std::vector<ndk::ScopedFileDescriptor>& modelCache,
+                                         const std::vector<ndk::ScopedFileDescriptor>& dataCache,
+                                         const Model* model, const TestModel& testModel) {
+        std::shared_ptr<IPreparedModel> preparedModel;
+        ErrorStatus status;
+
+        // Verify that prepareModelFromCache fails either due to bad
+        // arguments (INVALID_ARGUMENT) or GENERAL_FAILURE if not supported.
+        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status,
+                              /*fallbackModel=*/nullptr);
+        if (status != ErrorStatus::INVALID_ARGUMENT) {
+            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
+        }
+        ASSERT_EQ(preparedModel, nullptr);
+
+        // If caching is not supported, attempt calling prepareModel.
+        if (status == ErrorStatus::GENERAL_FAILURE) {
+            // Fallback with prepareModel should succeed regardless of cache files
+            prepareModelFromCache(modelCache, dataCache, &preparedModel, &status,
+                                  /*fallbackModel=*/model);
+            // Unless caching is not supported?
+            if (status != ErrorStatus::GENERAL_FAILURE) {
+                // But if it is, we should see a valid model.
+                ASSERT_EQ(status, ErrorStatus::NONE);
+                ASSERT_NE(preparedModel, nullptr);
+                EvaluatePreparedModel(kDevice, preparedModel, testModel,
+                                      /*testKind=*/TestKind::GENERAL);
+            }
+        }
+    }
+
     // Absolute path to the temporary cache directory.
     std::string mCacheDir;
 
@@ -397,7 +457,7 @@
     uint8_t mToken[static_cast<uint32_t>(IDevice::BYTE_SIZE_OF_CACHE_TOKEN)] = {};
     uint32_t mNumModelCache;
     uint32_t mNumDataCache;
-    uint32_t mIsCachingSupported;
+    bool mIsCachingSupported;
 
     const std::shared_ptr<IDevice> kDevice;
     // The primary data type of the testModel.
@@ -438,7 +498,8 @@
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         createCacheFds(mModelCache, AccessMode::READ_WRITE, &modelCache);
         createCacheFds(mDataCache, AccessMode::READ_WRITE, &dataCache);
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
+        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status,
+                              /*fallbackModel=*/&model);
         if (!mIsCachingSupported) {
             ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
             ASSERT_EQ(preparedModel, nullptr);
@@ -498,7 +559,8 @@
         for (uint32_t i = 0; i < dataCache.size(); i++) {
             ASSERT_GE(read(dataCache[i].get(), &placeholderByte, 1), 0);
         }
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
+        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status,
+                              /*fallbackModel=*/&model);
         if (!mIsCachingSupported) {
             ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
             ASSERT_EQ(preparedModel, nullptr);
@@ -536,13 +598,7 @@
         // Execute and verify results.
         EvaluatePreparedModel(kDevice, preparedModel, testModel, /*testKind=*/TestKind::GENERAL);
         // Check if prepareModelFromCache fails.
-        preparedModel = nullptr;
-        ErrorStatus status;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::INVALID_ARGUMENT) {
-            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Test with number of model cache files smaller than mNumModelCache.
@@ -560,13 +616,7 @@
         // Execute and verify results.
         EvaluatePreparedModel(kDevice, preparedModel, testModel, /*testKind=*/TestKind::GENERAL);
         // Check if prepareModelFromCache fails.
-        preparedModel = nullptr;
-        ErrorStatus status;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::INVALID_ARGUMENT) {
-            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Test with number of data cache files greater than mNumDataCache.
@@ -583,13 +633,7 @@
         // Execute and verify results.
         EvaluatePreparedModel(kDevice, preparedModel, testModel, /*testKind=*/TestKind::GENERAL);
         // Check if prepareModelFromCache fails.
-        preparedModel = nullptr;
-        ErrorStatus status;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::INVALID_ARGUMENT) {
-            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Test with number of data cache files smaller than mNumDataCache.
@@ -607,13 +651,7 @@
         // Execute and verify results.
         EvaluatePreparedModel(kDevice, preparedModel, testModel, /*testKind=*/TestKind::GENERAL);
         // Check if prepareModelFromCache fails.
-        preparedModel = nullptr;
-        ErrorStatus status;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::INVALID_ARGUMENT) {
-            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 }
 
@@ -633,68 +671,48 @@
 
     // Test with number of model cache files greater than mNumModelCache.
     {
-        std::shared_ptr<IPreparedModel> preparedModel = nullptr;
-        ErrorStatus status;
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         mModelCache.push_back({mTmpCache});
         createCacheFds(mModelCache, AccessMode::READ_WRITE, &modelCache);
         createCacheFds(mDataCache, AccessMode::READ_WRITE, &dataCache);
         mModelCache.pop_back();
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::GENERAL_FAILURE) {
-            ASSERT_EQ(status, ErrorStatus::INVALID_ARGUMENT);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Test with number of model cache files smaller than mNumModelCache.
     if (mModelCache.size() > 0) {
-        std::shared_ptr<IPreparedModel> preparedModel = nullptr;
-        ErrorStatus status;
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         auto tmp = mModelCache.back();
         mModelCache.pop_back();
         createCacheFds(mModelCache, AccessMode::READ_WRITE, &modelCache);
         createCacheFds(mDataCache, AccessMode::READ_WRITE, &dataCache);
         mModelCache.push_back(tmp);
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::GENERAL_FAILURE) {
-            ASSERT_EQ(status, ErrorStatus::INVALID_ARGUMENT);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Test with number of data cache files greater than mNumDataCache.
     {
-        std::shared_ptr<IPreparedModel> preparedModel = nullptr;
-        ErrorStatus status;
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         mDataCache.push_back({mTmpCache});
         createCacheFds(mModelCache, AccessMode::READ_WRITE, &modelCache);
         createCacheFds(mDataCache, AccessMode::READ_WRITE, &dataCache);
         mDataCache.pop_back();
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::GENERAL_FAILURE) {
-            ASSERT_EQ(status, ErrorStatus::INVALID_ARGUMENT);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Test with number of data cache files smaller than mNumDataCache.
     if (mDataCache.size() > 0) {
-        std::shared_ptr<IPreparedModel> preparedModel = nullptr;
-        ErrorStatus status;
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         auto tmp = mDataCache.back();
         mDataCache.pop_back();
         createCacheFds(mModelCache, AccessMode::READ_WRITE, &modelCache);
         createCacheFds(mDataCache, AccessMode::READ_WRITE, &dataCache);
         mDataCache.push_back(tmp);
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::GENERAL_FAILURE) {
-            ASSERT_EQ(status, ErrorStatus::INVALID_ARGUMENT);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 }
 
@@ -719,13 +737,7 @@
         // Execute and verify results.
         EvaluatePreparedModel(kDevice, preparedModel, testModel, /*testKind=*/TestKind::GENERAL);
         // Check if prepareModelFromCache fails.
-        preparedModel = nullptr;
-        ErrorStatus status;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::INVALID_ARGUMENT) {
-            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Go through each handle in data cache, test with invalid access mode.
@@ -741,13 +753,7 @@
         // Execute and verify results.
         EvaluatePreparedModel(kDevice, preparedModel, testModel, /*testKind=*/TestKind::GENERAL);
         // Check if prepareModelFromCache fails.
-        preparedModel = nullptr;
-        ErrorStatus status;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        if (status != ErrorStatus::INVALID_ARGUMENT) {
-            ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        }
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 }
 
@@ -769,30 +775,23 @@
 
     // Go through each handle in model cache, test with invalid access mode.
     for (uint32_t i = 0; i < mNumModelCache; i++) {
-        std::shared_ptr<IPreparedModel> preparedModel = nullptr;
-        ErrorStatus status;
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         modelCacheMode[i] = AccessMode::WRITE_ONLY;
         createCacheFds(mModelCache, modelCacheMode, &modelCache);
         createCacheFds(mDataCache, dataCacheMode, &dataCache);
         modelCacheMode[i] = AccessMode::READ_WRITE;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        ASSERT_EQ(preparedModel, nullptr);
+
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 
     // Go through each handle in data cache, test with invalid access mode.
     for (uint32_t i = 0; i < mNumDataCache; i++) {
-        std::shared_ptr<IPreparedModel> preparedModel = nullptr;
-        ErrorStatus status;
         std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
         dataCacheMode[i] = AccessMode::WRITE_ONLY;
         createCacheFds(mModelCache, modelCacheMode, &modelCache);
         createCacheFds(mDataCache, dataCacheMode, &dataCache);
         dataCacheMode[i] = AccessMode::READ_WRITE;
-        prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
-        ASSERT_EQ(status, ErrorStatus::GENERAL_FAILURE);
-        ASSERT_EQ(preparedModel, nullptr);
+        verifyModelPreparationBehaviour(modelCache, dataCache, &model, testModel);
     }
 }
 
@@ -872,7 +871,8 @@
             std::vector<ndk::ScopedFileDescriptor> modelCache, dataCache;
             createCacheFds(mModelCache, AccessMode::READ_WRITE, &modelCache);
             createCacheFds(mDataCache, AccessMode::READ_WRITE, &dataCache);
-            prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
+            prepareModelFromCache(modelCache, dataCache, &preparedModel, &status,
+                                  /*fallbackModel=*/nullptr);
 
             // The preparation may fail or succeed, but must not crash. If the preparation succeeds,
             // the prepared model must be executed with the correct result and not crash.
@@ -933,7 +933,8 @@
 
             // Spawn a thread to copy the cache content concurrently while preparing from cache.
             std::thread thread(copyCacheFiles, std::cref(modelCacheMul), std::cref(mModelCache));
-            prepareModelFromCache(modelCache, dataCache, &preparedModel, &status);
+            prepareModelFromCache(modelCache, dataCache, &preparedModel, &status,
+                                  /*fallbackModel=*/nullptr);
             thread.join();
 
             // The preparation may fail or succeed, but must not crash. If the preparation succeeds,
diff --git a/security/secureclock/aidl/android/hardware/security/secureclock/TimeStampToken.aidl b/security/secureclock/aidl/android/hardware/security/secureclock/TimeStampToken.aidl
index 2fbd29a..fcf2ee8 100644
--- a/security/secureclock/aidl/android/hardware/security/secureclock/TimeStampToken.aidl
+++ b/security/secureclock/aidl/android/hardware/security/secureclock/TimeStampToken.aidl
@@ -39,7 +39,7 @@
      * 32-byte HMAC-SHA256 of the above values, computed as:
      *
      *    HMAC(H,
-     *         ISecureClock.TIME_STAMP_MAC_LABEL || challenge || timestamp || securityLevel )
+     *         ISecureClock.TIME_STAMP_MAC_LABEL || challenge || timestamp || 1 )
      *
      * where:
      *
@@ -50,9 +50,7 @@
      *   ``||'' represents concatenation
      *
      * The representation of challenge and timestamp is as 64-bit unsigned integers in big-endian
-     * order. SecurityLevel is represented as a 32-bit unsigned integer in big-endian order as
-     * described in android.hardware.security.keymint.SecurityLevel. It represents the security
-     * level of the secure clock environment.
+     * order.  1, above, is a 32-bit unsigned integer, also big-endian.
      */
     byte[] mac;
 }