Merge changes Id0e18bef,Ie2b5f559 am: 5bf384cae9 am: e5d8f60389 am: 500579cd2b

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1531240

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I44fcae82534c876bec19f9c90d05dd363727be9b

6 files changed, 390 insertions, 92 deletions

diff --git a/services/core/java/com/android/server/locksettings/AesEncryptionUtil.java b/services/core/java/com/android/server/locksettings/AesEncryptionUtil.java
new file mode 100644
index 000000000000..8e7e419a6b0e
--- /dev/null
+++ b/services/core/java/com/android/server/locksettings/AesEncryptionUtil.java
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.locksettings;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.util.Objects;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.GCMParameterSpec;
+
+class AesEncryptionUtil {
+    /** The algorithm used for the encryption of the key blob. */
+    private static final String CIPHER_ALGO = "AES/GCM/NoPadding";
+
+    private AesEncryptionUtil() {}
+
+    static byte[] decrypt(SecretKey key, DataInputStream cipherStream) throws IOException {
+        Objects.requireNonNull(key);
+        Objects.requireNonNull(cipherStream);
+
+        int ivSize = cipherStream.readInt();
+        if (ivSize < 0 || ivSize > 32) {
+            throw new IOException("IV out of range: " + ivSize);
+        }
+        byte[] iv = new byte[ivSize];
+        cipherStream.readFully(iv);
+
+        int rawCipherTextSize = cipherStream.readInt();
+        if (rawCipherTextSize < 0) {
+            throw new IOException("Invalid cipher text size: " + rawCipherTextSize);
+        }
+
+        byte[] rawCipherText = new byte[rawCipherTextSize];
+        cipherStream.readFully(rawCipherText);
+
+        final byte[] plainText;
+        try {
+            Cipher c = Cipher.getInstance(CIPHER_ALGO);
+            c.init(Cipher.DECRYPT_MODE, key, new GCMParameterSpec(128, iv));
+            plainText = c.doFinal(rawCipherText);
+        } catch (NoSuchAlgorithmException | InvalidKeyException | BadPaddingException
+                | IllegalBlockSizeException | NoSuchPaddingException
+                | InvalidAlgorithmParameterException e) {
+            throw new IOException("Could not decrypt cipher text", e);
+        }
+
+        return plainText;
+    }
+
+    static byte[] decrypt(SecretKey key, byte[] cipherText) throws IOException {
+        Objects.requireNonNull(key);
+        Objects.requireNonNull(cipherText);
+
+        DataInputStream cipherStream = new DataInputStream(new ByteArrayInputStream(cipherText));
+        return decrypt(key, cipherStream);
+    }
+
+    static byte[] encrypt(SecretKey key, byte[] plainText) throws IOException {
+        Objects.requireNonNull(key);
+        Objects.requireNonNull(plainText);
+
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        DataOutputStream dos = new DataOutputStream(bos);
+
+        final byte[] cipherText;
+        final byte[] iv;
+        try {
+            Cipher cipher = Cipher.getInstance(CIPHER_ALGO);
+            cipher.init(Cipher.ENCRYPT_MODE, key);
+            cipherText = cipher.doFinal(plainText);
+            iv = cipher.getIV();
+        } catch (NoSuchAlgorithmException | BadPaddingException | IllegalBlockSizeException
+                | NoSuchPaddingException | InvalidKeyException e) {
+            throw new IOException("Could not encrypt input data", e);
+        }
+
+        dos.writeInt(iv.length);
+        dos.write(iv);
+        dos.writeInt(cipherText.length);
+        dos.write(cipherText);
+
+        return bos.toByteArray();
+    }
+}
diff --git a/services/core/java/com/android/server/locksettings/RebootEscrowData.java b/services/core/java/com/android/server/locksettings/RebootEscrowData.java
index 2b1907985aeb..38eeb88e63b0 100644
--- a/services/core/java/com/android/server/locksettings/RebootEscrowData.java
+++ b/services/core/java/com/android/server/locksettings/RebootEscrowData.java
@@ -16,22 +16,14 @@
 
 package com.android.server.locksettings;
 
-import com.android.internal.util.Preconditions;
-
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
 import java.io.IOException;
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.NoSuchAlgorithmException;
+import java.util.Objects;
 
-import javax.crypto.BadPaddingException;
-import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
-import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.SecretKey;
 
 /**
  * Holds the data necessary to complete a reboot escrow of the Synthetic Password.
@@ -41,22 +33,17 @@ class RebootEscrowData {
      * This is the current version of the escrow data format. This should be incremented if the
      * format on disk is changed.
      */
-    private static final int CURRENT_VERSION = 1;
-
-    /** The algorithm used for the encryption of the key blob. */
-    private static final String CIPHER_ALGO = "AES/GCM/NoPadding";
+    private static final int CURRENT_VERSION = 2;
 
-    private RebootEscrowData(byte spVersion, byte[] iv, byte[] syntheticPassword, byte[] blob,
+    private RebootEscrowData(byte spVersion, byte[] syntheticPassword, byte[] blob,
             RebootEscrowKey key) {
         mSpVersion = spVersion;
-        mIv = iv;
         mSyntheticPassword = syntheticPassword;
         mBlob = blob;
         mKey = key;
     }
 
     private final byte mSpVersion;
-    private final byte[] mIv;
     private final byte[] mSyntheticPassword;
     private final byte[] mBlob;
     private final RebootEscrowKey mKey;
@@ -65,10 +52,6 @@ class RebootEscrowData {
         return mSpVersion;
     }
 
-    public byte[] getIv() {
-        return mIv;
-    }
-
     public byte[] getSyntheticPassword() {
         return mSyntheticPassword;
     }
@@ -81,76 +64,43 @@ class RebootEscrowData {
         return mKey;
     }
 
-    static RebootEscrowData fromEncryptedData(RebootEscrowKey key, byte[] blob)
+    static RebootEscrowData fromEncryptedData(RebootEscrowKey ks, byte[] blob, SecretKey kk)
             throws IOException {
-        Preconditions.checkNotNull(key);
-        Preconditions.checkNotNull(blob);
+        Objects.requireNonNull(ks);
+        Objects.requireNonNull(blob);
 
         DataInputStream dis = new DataInputStream(new ByteArrayInputStream(blob));
         int version = dis.readInt();
         if (version != CURRENT_VERSION) {
             throw new IOException("Unsupported version " + version);
         }
-
         byte spVersion = dis.readByte();
 
-        int ivSize = dis.readInt();
-        if (ivSize < 0 || ivSize > 32) {
-            throw new IOException("IV out of range: " + ivSize);
-        }
-        byte[] iv = new byte[ivSize];
-        dis.readFully(iv);
+        // Decrypt the blob with the key from keystore first, then decrypt again with the reboot
+        // escrow key.
+        byte[] ksEncryptedBlob = AesEncryptionUtil.decrypt(kk, dis);
+        final byte[] syntheticPassword = AesEncryptionUtil.decrypt(ks.getKey(), ksEncryptedBlob);
 
-        int cipherTextSize = dis.readInt();
-        if (cipherTextSize < 0) {
-            throw new IOException("Invalid cipher text size: " + cipherTextSize);
-        }
-
-        byte[] cipherText = new byte[cipherTextSize];
-        dis.readFully(cipherText);
-
-        final byte[] syntheticPassword;
-        try {
-            Cipher c = Cipher.getInstance(CIPHER_ALGO);
-            c.init(Cipher.DECRYPT_MODE, key.getKey(), new IvParameterSpec(iv));
-            syntheticPassword = c.doFinal(cipherText);
-        } catch (NoSuchAlgorithmException | InvalidKeyException | BadPaddingException
-                | IllegalBlockSizeException | NoSuchPaddingException
-                | InvalidAlgorithmParameterException e) {
-            throw new IOException("Could not decrypt ciphertext", e);
-        }
-
-        return new RebootEscrowData(spVersion, iv, syntheticPassword, blob, key);
+        return new RebootEscrowData(spVersion, syntheticPassword, blob, ks);
     }
 
-    static RebootEscrowData fromSyntheticPassword(RebootEscrowKey key, byte spVersion,
-            byte[] syntheticPassword)
+    static RebootEscrowData fromSyntheticPassword(RebootEscrowKey ks, byte spVersion,
+            byte[] syntheticPassword, SecretKey kk)
             throws IOException {
-        Preconditions.checkNotNull(syntheticPassword);
+        Objects.requireNonNull(syntheticPassword);
+
+        // Encrypt synthetic password with the escrow key first; then encrypt the blob again with
+        // the key from keystore.
+        byte[] ksEncryptedBlob = AesEncryptionUtil.encrypt(ks.getKey(), syntheticPassword);
+        byte[] kkEncryptedBlob = AesEncryptionUtil.encrypt(kk, ksEncryptedBlob);
 
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         DataOutputStream dos = new DataOutputStream(bos);
 
-        final byte[] cipherText;
-        final byte[] iv;
-        try {
-            Cipher cipher = Cipher.getInstance(CIPHER_ALGO);
-            cipher.init(Cipher.ENCRYPT_MODE, key.getKey());
-            cipherText = cipher.doFinal(syntheticPassword);
-            iv = cipher.getIV();
-        } catch (NoSuchAlgorithmException | BadPaddingException | IllegalBlockSizeException
-                | NoSuchPaddingException | InvalidKeyException e) {
-            throw new IOException("Could not encrypt reboot escrow data", e);
-        }
-
         dos.writeInt(CURRENT_VERSION);
         dos.writeByte(spVersion);
-        dos.writeInt(iv.length);
-        dos.write(iv);
-        dos.writeInt(cipherText.length);
-        dos.write(cipherText);
+        dos.write(kkEncryptedBlob);
 
-        return new RebootEscrowData(spVersion, iv, syntheticPassword, bos.toByteArray(),
-                key);
+        return new RebootEscrowData(spVersion, syntheticPassword, bos.toByteArray(), ks);
     }
 }
diff --git a/services/core/java/com/android/server/locksettings/RebootEscrowKeyStoreManager.java b/services/core/java/com/android/server/locksettings/RebootEscrowKeyStoreManager.java
new file mode 100644
index 000000000000..bae029c79968
--- /dev/null
+++ b/services/core/java/com/android/server/locksettings/RebootEscrowKeyStoreManager.java
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.locksettings;
+
+import android.security.keystore.AndroidKeyStoreSpi;
+import android.security.keystore.KeyGenParameterSpec;
+import android.security.keystore.KeyProperties;
+import android.security.keystore2.AndroidKeyStoreLoadStoreParameter;
+import android.security.keystore2.AndroidKeyStoreProvider;
+import android.util.Slog;
+
+import com.android.internal.annotations.GuardedBy;
+
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.security.KeyStore;
+
+import javax.crypto.KeyGenerator;
+import javax.crypto.SecretKey;
+
+/**
+ * This class loads and generates the key used for resume on reboot from android keystore.
+ */
+public class RebootEscrowKeyStoreManager {
+    private static final String TAG = "RebootEscrowKeyStoreManager";
+
+    /**
+     * The key alias in keystore. This key is used to wrap both escrow key and escrow data.
+     */
+    public static final String REBOOT_ESCROW_KEY_STORE_ENCRYPTION_KEY_NAME =
+            "reboot_escrow_key_store_encryption_key";
+
+    public static final int KEY_LENGTH = 256;
+
+    /**
+     * Use keystore2 once it's installed.
+     */
+    private static final String ANDROID_KEY_STORE_PROVIDER = "AndroidKeystore";
+
+    /**
+     * The selinux namespace for resume_on_reboot_key
+     */
+    private static final int KEY_STORE_NAMESPACE = 120;
+
+    /**
+     * Hold this lock when getting or generating the encryption key in keystore.
+     */
+    private final Object mKeyStoreLock = new Object();
+
+    @GuardedBy("mKeyStoreLock")
+    private SecretKey getKeyStoreEncryptionKeyLocked() {
+        try {
+            KeyStore keyStore = KeyStore.getInstance(ANDROID_KEY_STORE_PROVIDER);
+            KeyStore.LoadStoreParameter loadStoreParameter = null;
+            // Load from the specific namespace if keystore2 is enabled.
+            if (AndroidKeyStoreProvider.isInstalled()) {
+                loadStoreParameter = new AndroidKeyStoreLoadStoreParameter(KEY_STORE_NAMESPACE);
+            }
+            keyStore.load(loadStoreParameter);
+            return (SecretKey) keyStore.getKey(REBOOT_ESCROW_KEY_STORE_ENCRYPTION_KEY_NAME,
+                    null);
+        } catch (IOException | GeneralSecurityException e) {
+            Slog.e(TAG, "Unable to get encryption key from keystore.", e);
+        }
+        return null;
+    }
+
+    protected SecretKey getKeyStoreEncryptionKey() {
+        synchronized (mKeyStoreLock) {
+            return getKeyStoreEncryptionKeyLocked();
+        }
+    }
+
+    protected void clearKeyStoreEncryptionKey() {
+        synchronized (mKeyStoreLock) {
+            try {
+                KeyStore keyStore = KeyStore.getInstance(ANDROID_KEY_STORE_PROVIDER);
+                KeyStore.LoadStoreParameter loadStoreParameter = null;
+                // Load from the specific namespace if keystore2 is enabled.
+                if (AndroidKeyStoreProvider.isInstalled()) {
+                    loadStoreParameter = new AndroidKeyStoreLoadStoreParameter(KEY_STORE_NAMESPACE);
+                }
+                keyStore.load(loadStoreParameter);
+                keyStore.deleteEntry(REBOOT_ESCROW_KEY_STORE_ENCRYPTION_KEY_NAME);
+            } catch (IOException | GeneralSecurityException e) {
+                Slog.e(TAG, "Unable to delete encryption key in keystore.", e);
+            }
+        }
+    }
+
+    protected SecretKey generateKeyStoreEncryptionKeyIfNeeded() {
+        synchronized (mKeyStoreLock) {
+            SecretKey kk = getKeyStoreEncryptionKeyLocked();
+            if (kk != null) {
+                return kk;
+            }
+
+            try {
+                KeyGenerator generator = KeyGenerator.getInstance(
+                        KeyProperties.KEY_ALGORITHM_AES, AndroidKeyStoreSpi.NAME);
+                KeyGenParameterSpec.Builder parameterSpecBuilder = new KeyGenParameterSpec.Builder(
+                        REBOOT_ESCROW_KEY_STORE_ENCRYPTION_KEY_NAME,
+                        KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
+                        .setKeySize(KEY_LENGTH)
+                        .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
+                        .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE);
+                // Generate the key with the correct namespace if keystore2 is enabled.
+                if (AndroidKeyStoreProvider.isInstalled()) {
+                    parameterSpecBuilder.setNamespace(KEY_STORE_NAMESPACE);
+                }
+                generator.init(parameterSpecBuilder.build());
+                return generator.generateKey();
+            } catch (GeneralSecurityException e) {
+                // Should never happen.
+                Slog.e(TAG, "Unable to generate key from keystore.", e);
+            }
+            return null;
+        }
+    }
+}
diff --git a/services/core/java/com/android/server/locksettings/RebootEscrowManager.java b/services/core/java/com/android/server/locksettings/RebootEscrowManager.java
index 8d5f553dba5c..289290bab4dc 100644
--- a/services/core/java/com/android/server/locksettings/RebootEscrowManager.java
+++ b/services/core/java/com/android/server/locksettings/RebootEscrowManager.java
@@ -40,6 +40,18 @@ import java.util.Date;
 import java.util.List;
 import java.util.Locale;
 
+import javax.crypto.SecretKey;
+
+/**
+ * This class aims to persists the synthetic password(SP) across reboot in a secure way. In
+ * particular, it manages the encryption of the sp before reboot, and decryption of the sp after
+ * reboot. Here are the meaning of some terms.
+ *   SP: synthetic password
+ *   K_s: The RebootEscrowKey, i.e. AES-GCM key stored in memory
+ *   K_k: AES-GCM key in android keystore
+ *   RebootEscrowData: The synthetic password and its encrypted blob. We encrypt SP with K_s first,
+ *      then with K_k, i.e. E(K_k, E(K_s, SP))
+ */
 class RebootEscrowManager {
     private static final String TAG = "RebootEscrowManager";
 
@@ -101,6 +113,8 @@ class RebootEscrowManager {
 
     private final Callbacks mCallbacks;
 
+    private final RebootEscrowKeyStoreManager mKeyStoreManager;
+
     interface Callbacks {
         boolean isUserSecure(int userId);
 
@@ -109,11 +123,13 @@ class RebootEscrowManager {
 
     static class Injector {
         protected Context mContext;
-
+        private final RebootEscrowKeyStoreManager mKeyStoreManager;
         private final RebootEscrowProviderInterface mRebootEscrowProvider;
 
         Injector(Context context) {
             mContext = context;
+            mKeyStoreManager = new RebootEscrowKeyStoreManager();
+
             RebootEscrowProviderInterface rebootEscrowProvider = null;
             // TODO(xunchang) add implementation for server based ror.
             if (DeviceConfig.getBoolean(DeviceConfig.NAMESPACE_OTA,
@@ -138,6 +154,10 @@ class RebootEscrowManager {
             return (UserManager) mContext.getSystemService(Context.USER_SERVICE);
         }
 
+        public RebootEscrowKeyStoreManager getKeyStoreManager() {
+            return mKeyStoreManager;
+        }
+
         public RebootEscrowProviderInterface getRebootEscrowProvider() {
             return mRebootEscrowProvider;
         }
@@ -168,6 +188,7 @@ class RebootEscrowManager {
         mStorage = storage;
         mUserManager = injector.getUserManager();
         mEventLog = injector.getEventLog();
+        mKeyStoreManager = injector.getKeyStoreManager();
     }
 
     void loadRebootEscrowDataIfAvailable() {
@@ -183,8 +204,12 @@ class RebootEscrowManager {
             return;
         }
 
-        RebootEscrowKey escrowKey = getAndClearRebootEscrowKey();
-        if (escrowKey == null) {
+        // Fetch the key from keystore to decrypt the escrow data & escrow key; this key is
+        // generated before reboot. Note that we will clear the escrow key even if the keystore key
+        // is null.
+        SecretKey kk = mKeyStoreManager.getKeyStoreEncryptionKey();
+        RebootEscrowKey escrowKey = getAndClearRebootEscrowKey(kk);
+        if (kk == null || escrowKey == null) {
             Slog.w(TAG, "Had reboot escrow data for users, but no key; removing escrow storage.");
             for (UserInfo user : users) {
                 mStorage.removeRebootEscrow(user.id);
@@ -197,7 +222,7 @@ class RebootEscrowManager {
 
         boolean allUsersUnlocked = true;
         for (UserInfo user : rebootEscrowUsers) {
-            allUsersUnlocked &= restoreRebootEscrowForUser(user.id, escrowKey);
+            allUsersUnlocked &= restoreRebootEscrowForUser(user.id, escrowKey, kk);
         }
         onEscrowRestoreComplete(allUsersUnlocked);
     }
@@ -212,7 +237,7 @@ class RebootEscrowManager {
         }
     }
 
-    private RebootEscrowKey getAndClearRebootEscrowKey() {
+    private RebootEscrowKey getAndClearRebootEscrowKey(SecretKey kk) {
         RebootEscrowProviderInterface rebootEscrowProvider = mInjector.getRebootEscrowProvider();
         if (rebootEscrowProvider == null) {
             Slog.w(TAG,
@@ -220,14 +245,16 @@ class RebootEscrowManager {
             return null;
         }
 
-        RebootEscrowKey key = rebootEscrowProvider.getAndClearRebootEscrowKey(null);
+        // The K_s blob maybe encrypted by K_k as well.
+        RebootEscrowKey key = rebootEscrowProvider.getAndClearRebootEscrowKey(kk);
         if (key != null) {
             mEventLog.addEntry(RebootEscrowEvent.RETRIEVED_STORED_KEK);
         }
         return key;
     }
 
-    private boolean restoreRebootEscrowForUser(@UserIdInt int userId, RebootEscrowKey key) {
+    private boolean restoreRebootEscrowForUser(@UserIdInt int userId, RebootEscrowKey ks,
+            SecretKey kk) {
         if (!mStorage.hasRebootEscrow(userId)) {
             return false;
         }
@@ -236,7 +263,7 @@ class RebootEscrowManager {
             byte[] blob = mStorage.readRebootEscrow(userId);
             mStorage.removeRebootEscrow(userId);
 
-            RebootEscrowData escrowData = RebootEscrowData.fromEncryptedData(key, blob);
+            RebootEscrowData escrowData = RebootEscrowData.fromEncryptedData(ks, blob, kk);
 
             mCallbacks.onRebootEscrowRestored(escrowData.getSpVersion(),
                     escrowData.getSyntheticPassword(), userId);
@@ -246,6 +273,9 @@ class RebootEscrowManager {
         } catch (IOException e) {
             Slog.w(TAG, "Could not load reboot escrow data for user " + userId, e);
             return false;
+        } finally {
+            // Clear the old key in keystore. A new key will be generated by new RoR requests.
+            mKeyStoreManager.clearKeyStoreEncryptionKey();
         }
     }
 
@@ -267,11 +297,16 @@ class RebootEscrowManager {
             return;
         }
 
+        SecretKey kk = mKeyStoreManager.generateKeyStoreEncryptionKeyIfNeeded();
+        if (kk == null) {
+            Slog.e(TAG, "Failed to generate encryption key from keystore.");
+            return;
+        }
+
         final RebootEscrowData escrowData;
         try {
-            // TODO(xunchang) further wrap the escrowData with a key from keystore.
             escrowData = RebootEscrowData.fromSyntheticPassword(escrowKey, spVersion,
-                    syntheticPassword);
+                    syntheticPassword, kk);
         } catch (IOException e) {
             setRebootEscrowReady(false);
             Slog.w(TAG, "Could not escrow reboot data", e);
@@ -348,7 +383,13 @@ class RebootEscrowManager {
             return false;
         }
 
-        boolean armedRebootEscrow = rebootEscrowProvider.storeRebootEscrowKey(escrowKey, null);
+        // We will use the same key from keystore to encrypt the escrow key and escrow data blob.
+        SecretKey kk = mKeyStoreManager.getKeyStoreEncryptionKey();
+        if (kk == null) {
+            Slog.e(TAG, "Failed to get encryption key from keystore.");
+            return false;
+        }
+        boolean armedRebootEscrow = rebootEscrowProvider.storeRebootEscrowKey(escrowKey, kk);
         if (armedRebootEscrow) {
             mStorage.setInt(REBOOT_ESCROW_ARMED_KEY, mInjector.getBootCount(), USER_SYSTEM);
             mEventLog.addEntry(RebootEscrowEvent.SET_ARMED_STATUS);
diff --git a/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowDataTest.java b/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowDataTest.java
index 46f43e7af596..32445fd1a47d 100644
--- a/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowDataTest.java
+++ b/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowDataTest.java
@@ -19,22 +19,44 @@ package com.android.server.locksettings;
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.assertThat;
 
+import android.security.keystore.KeyGenParameterSpec;
+import android.security.keystore.KeyProperties;
+
 import androidx.test.runner.AndroidJUnit4;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.security.GeneralSecurityException;
+
+import javax.crypto.KeyGenerator;
+import javax.crypto.SecretKey;
+
 /**
  * atest FrameworksServicesTests:RebootEscrowDataTest
  */
 @RunWith(AndroidJUnit4.class)
 public class RebootEscrowDataTest {
     private RebootEscrowKey mKey;
+    private SecretKey mKeyStoreEncryptionKey;
+
+    private SecretKey generateNewRebootEscrowEncryptionKey() throws GeneralSecurityException {
+        KeyGenerator generator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES);
+        generator.init(new KeyGenParameterSpec.Builder(
+                "reboot_escrow_data_test_key",
+                KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
+                .setKeySize(256)
+                .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
+                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
+                .build());
+        return generator.generateKey();
+    }
 
     @Before
     public void generateKey() throws Exception {
         mKey = RebootEscrowKey.generate();
+        mKeyStoreEncryptionKey = generateNewRebootEscrowEncryptionKey();
     }
 
     private static byte[] getTestSp() {
@@ -47,36 +69,49 @@ public class RebootEscrowDataTest {
 
     @Test(expected = NullPointerException.class)
     public void fromEntries_failsOnNull() throws Exception {
-        RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, null);
+        RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, null, mKeyStoreEncryptionKey);
     }
 
     @Test(expected = NullPointerException.class)
     public void fromEncryptedData_failsOnNullData() throws Exception {
         byte[] testSp = getTestSp();
-        RebootEscrowData expected = RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, testSp);
+        RebootEscrowData expected = RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, testSp,
+                mKeyStoreEncryptionKey);
         RebootEscrowKey key = RebootEscrowKey.fromKeyBytes(expected.getKey().getKeyBytes());
-        RebootEscrowData.fromEncryptedData(key, null);
+        RebootEscrowData.fromEncryptedData(key, null, mKeyStoreEncryptionKey);
     }
 
     @Test(expected = NullPointerException.class)
     public void fromEncryptedData_failsOnNullKey() throws Exception {
         byte[] testSp = getTestSp();
-        RebootEscrowData expected = RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, testSp);
-        RebootEscrowData.fromEncryptedData(null, expected.getBlob());
+        RebootEscrowData expected = RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, testSp,
+                mKeyStoreEncryptionKey);
+        RebootEscrowData.fromEncryptedData(null, expected.getBlob(), mKeyStoreEncryptionKey);
     }
 
     @Test
     public void fromEntries_loopback_success() throws Exception {
         byte[] testSp = getTestSp();
-        RebootEscrowData expected = RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, testSp);
+        RebootEscrowData expected = RebootEscrowData.fromSyntheticPassword(mKey, (byte) 2, testSp,
+                mKeyStoreEncryptionKey);
 
         RebootEscrowKey key = RebootEscrowKey.fromKeyBytes(expected.getKey().getKeyBytes());
-        RebootEscrowData actual = RebootEscrowData.fromEncryptedData(key, expected.getBlob());
+        RebootEscrowData actual = RebootEscrowData.fromEncryptedData(key, expected.getBlob(),
+                mKeyStoreEncryptionKey);
 
         assertThat(actual.getSpVersion(), is(expected.getSpVersion()));
-        assertThat(actual.getIv(), is(expected.getIv()));
         assertThat(actual.getKey().getKeyBytes(), is(expected.getKey().getKeyBytes()));
         assertThat(actual.getBlob(), is(expected.getBlob()));
         assertThat(actual.getSyntheticPassword(), is(expected.getSyntheticPassword()));
     }
+
+    @Test
+    public void aesEncryptedBlob_loopback_success() throws Exception {
+        byte[] testSp = getTestSp();
+        byte [] encrypted = AesEncryptionUtil.encrypt(mKeyStoreEncryptionKey, testSp);
+        byte [] decrypted = AesEncryptionUtil.decrypt(mKeyStoreEncryptionKey, encrypted);
+
+        assertThat(decrypted, is(testSp));
+    }
+
 }
diff --git a/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowManagerTests.java b/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowManagerTests.java
index 98d64524d87a..f74e45b6e59b 100644
--- a/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowManagerTests.java
+++ b/services/tests/servicestests/src/com/android/server/locksettings/RebootEscrowManagerTests.java
@@ -61,6 +61,9 @@ import org.mockito.ArgumentCaptor;
 import java.io.File;
 import java.util.ArrayList;
 
+import javax.crypto.SecretKey;
+import javax.crypto.spec.SecretKeySpec;
+
 @SmallTest
 @Presubmit
 @RunWith(AndroidJUnit4.class)
@@ -77,15 +80,25 @@ public class RebootEscrowManagerTests {
             0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
     };
 
+    // Hex encoding of a randomly generated AES key for test.
+    private static final byte[] TEST_AES_KEY = new byte[] {
+            0x48, 0x19, 0x12, 0x54, 0x13, 0x13, 0x52, 0x31,
+            0x44, 0x74, 0x61, 0x54, 0x29, 0x74, 0x37, 0x61,
+            0x70, 0x70, 0x75, 0x25, 0x27, 0x31, 0x49, 0x09,
+            0x26, 0x52, 0x72, 0x63, 0x63, 0x61, 0x78, 0x23,
+    };
+
     private Context mContext;
     private UserManager mUserManager;
     private RebootEscrowManager.Callbacks mCallbacks;
     private IRebootEscrow mRebootEscrow;
+    private RebootEscrowKeyStoreManager mKeyStoreManager;
 
     LockSettingsStorageTestable mStorage;
 
     private MockableRebootEscrowInjected mInjected;
     private RebootEscrowManager mService;
+    private SecretKey mAesKey;
 
     public interface MockableRebootEscrowInjected {
         int getBootCount();
@@ -98,9 +111,11 @@ public class RebootEscrowManagerTests {
         private final RebootEscrowProviderInterface mRebootEscrowProvider;
         private final UserManager mUserManager;
         private final MockableRebootEscrowInjected mInjected;
+        private final RebootEscrowKeyStoreManager mKeyStoreManager;
 
         MockInjector(Context context, UserManager userManager,
                 IRebootEscrow rebootEscrow,
+                RebootEscrowKeyStoreManager keyStoreManager,
                 MockableRebootEscrowInjected injected) {
             super(context);
             mRebootEscrow = rebootEscrow;
@@ -114,6 +129,7 @@ public class RebootEscrowManagerTests {
                     };
             mRebootEscrowProvider = new RebootEscrowProviderHalImpl(halInjector);
             mUserManager = userManager;
+            mKeyStoreManager = keyStoreManager;
             mInjected = injected;
         }
 
@@ -128,6 +144,11 @@ public class RebootEscrowManagerTests {
         }
 
         @Override
+        public RebootEscrowKeyStoreManager getKeyStoreManager() {
+            return mKeyStoreManager;
+        }
+
+        @Override
         public int getBootCount() {
             return mInjected.getBootCount();
         }
@@ -144,6 +165,11 @@ public class RebootEscrowManagerTests {
         mUserManager = mock(UserManager.class);
         mCallbacks = mock(RebootEscrowManager.Callbacks.class);
         mRebootEscrow = mock(IRebootEscrow.class);
+        mKeyStoreManager = mock(RebootEscrowKeyStoreManager.class);
+        mAesKey = new SecretKeySpec(TEST_AES_KEY, "AES");
+
+        when(mKeyStoreManager.getKeyStoreEncryptionKey()).thenReturn(mAesKey);
+        when(mKeyStoreManager.generateKeyStoreEncryptionKeyIfNeeded()).thenReturn(mAesKey);
 
         mStorage = new LockSettingsStorageTestable(mContext,
                 new File(InstrumentationRegistry.getContext().getFilesDir(), "locksettings"));
@@ -160,7 +186,7 @@ public class RebootEscrowManagerTests {
         when(mCallbacks.isUserSecure(SECURE_SECONDARY_USER_ID)).thenReturn(true);
         mInjected = mock(MockableRebootEscrowInjected.class);
         mService = new RebootEscrowManager(new MockInjector(mContext, mUserManager, mRebootEscrow,
-                mInjected), mCallbacks, mStorage);
+                mKeyStoreManager, mInjected), mCallbacks, mStorage);
     }
 
     @Test
@@ -213,6 +239,7 @@ public class RebootEscrowManagerTests {
         assertNotNull(
                 mStorage.getString(RebootEscrowManager.REBOOT_ESCROW_ARMED_KEY, null, USER_SYSTEM));
         verify(mRebootEscrow).storeKey(any());
+        verify(mKeyStoreManager).getKeyStoreEncryptionKey();
 
         assertTrue(mStorage.hasRebootEscrow(PRIMARY_USER_ID));
         assertFalse(mStorage.hasRebootEscrow(NONSECURE_SECONDARY_USER_ID));
@@ -300,6 +327,7 @@ public class RebootEscrowManagerTests {
         ArgumentCaptor<byte[]> keyByteCaptor = ArgumentCaptor.forClass(byte[].class);
         assertTrue(mService.armRebootEscrowIfNeeded());
         verify(mRebootEscrow).storeKey(keyByteCaptor.capture());
+        verify(mKeyStoreManager).getKeyStoreEncryptionKey();
 
         assertTrue(mStorage.hasRebootEscrow(PRIMARY_USER_ID));
         assertFalse(mStorage.hasRebootEscrow(NONSECURE_SECONDARY_USER_ID));
@@ -314,6 +342,7 @@ public class RebootEscrowManagerTests {
         mService.loadRebootEscrowDataIfAvailable();
         verify(mRebootEscrow).retrieveKey();
         assertTrue(metricsSuccessCaptor.getValue());
+        verify(mKeyStoreManager).clearKeyStoreEncryptionKey();
     }
 
     @Test