LockSettingsService: migrate to its own keystore namespace

Moves keystore keys used by LockSettingsService to a separate
namespace, migrating existing key during boot if needed.
Affected keys are encryption keys for synthetic password blob,
unified profile challenge encryption key and unified profile
challenge cache key.

Bug: 184664830
Test: atest com.android.server.locksettings
Change-Id: Iac339e64812232875afa9dc6109b848b50b0ef2f

services/core/java/com/android/server/locksettings/LockSettingsService.java

@@ -30,6 +30,8 @@ import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PASSW
 import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PATTERN;
 import static com.android.internal.widget.LockPatternUtils.CREDENTIAL_TYPE_PIN;
 import static com.android.internal.widget.LockPatternUtils.EscrowTokenStateChangeCallback;
+import static com.android.internal.widget.LockPatternUtils.PROFILE_KEY_NAME_DECRYPT;
+import static com.android.internal.widget.LockPatternUtils.PROFILE_KEY_NAME_ENCRYPT;
 import static com.android.internal.widget.LockPatternUtils.SYNTHETIC_PASSWORD_HANDLE_KEY;
 import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_AFTER_LOCKOUT;
 import static com.android.internal.widget.LockPatternUtils.StrongAuthTracker.STRONG_AUTH_REQUIRED_FOR_UNATTENDED_UPDATE;
@@ -99,6 +101,7 @@ import android.security.keystore.recovery.KeyChainProtectionParams;
 import android.security.keystore.recovery.KeyChainSnapshot;
 import android.security.keystore.recovery.RecoveryCertPath;
 import android.security.keystore.recovery.WrappedApplicationKey;
+import android.security.keystore2.AndroidKeyStoreLoadStoreParameter;
 import android.security.keystore2.AndroidKeyStoreProvider;
 import android.service.gatekeeper.GateKeeperResponse;
 import android.service.gatekeeper.IGateKeeperService;
@@ -155,6 +158,7 @@ import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Date;
+import java.util.Enumeration;
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
@@ -226,6 +230,7 @@ public class LockSettingsService extends ILockSettings.Stub {
     private final SyntheticPasswordManager mSpManager;
 
     private final KeyStore mKeyStore;
+    private final java.security.KeyStore mJavaKeyStore;
     private final RecoverableKeyStoreManager mRecoverableKeyStoreManager;
     private ManagedProfilePasswordCache mManagedProfilePasswordCache;
 
@@ -535,16 +540,22 @@ public class LockSettingsService extends ILockSettings.Stub {
             return Settings.Secure.getIntForUser(contentResolver, keyName, defaultValue, userId);
         }
 
-        public @NonNull ManagedProfilePasswordCache getManagedProfilePasswordCache() {
+        public java.security.KeyStore getJavaKeyStore() {
             try {
                 java.security.KeyStore ks = java.security.KeyStore.getInstance(
                         SyntheticPasswordCrypto.androidKeystoreProviderName());
-                ks.load(null);
+                ks.load(new AndroidKeyStoreLoadStoreParameter(
-                return new ManagedProfilePasswordCache(ks, getUserManager());
+                        SyntheticPasswordCrypto.keyNamespace()));
+                return ks;
             } catch (Exception e) {
                 throw new IllegalStateException("Cannot load keystore", e);
             }
         }
+
+        public @NonNull ManagedProfilePasswordCache getManagedProfilePasswordCache(
+                java.security.KeyStore ks) {
+            return new ManagedProfilePasswordCache(ks, getUserManager());
+        }
     }
 
     public LockSettingsService(Context context) {
@@ -556,6 +567,7 @@ public class LockSettingsService extends ILockSettings.Stub {
         mInjector = injector;
         mContext = injector.getContext();
         mKeyStore = injector.getKeyStore();
+        mJavaKeyStore = injector.getJavaKeyStore();
         mRecoverableKeyStoreManager = injector.getRecoverableKeyStoreManager();
         mHandler = injector.getHandler(injector.getServiceThread());
         mStrongAuth = injector.getStrongAuth();
@@ -580,7 +592,7 @@ public class LockSettingsService extends ILockSettings.Stub {
         mRandom = new SecureRandom();
 
         mSpManager = injector.getSyntheticPasswordManager(mStorage);
-        mManagedProfilePasswordCache = injector.getManagedProfilePasswordCache();
+        mManagedProfilePasswordCache = injector.getManagedProfilePasswordCache(mJavaKeyStore);
         mBiometricDeferredQueue = new BiometricDeferredQueue(mContext, mSpManager, mHandler);
 
         mRebootEscrowManager = injector.getRebootEscrowManager(new RebootEscrowCallbacks(),
@@ -955,6 +967,21 @@ public class LockSettingsService extends ILockSettings.Stub {
             setString("migrated_wear_lockscreen_disabled", "true", 0);
             Slog.i(TAG, "Migrated lockscreen_disabled for Wear devices");
         }
+
+        if (getString("migrated_keystore_namespace", null, 0) == null) {
+            boolean success = true;
+            synchronized (mSpManager) {
+                success &= mSpManager.migrateKeyNamespace();
+            }
+            success &= migrateProfileLockKeys();
+            if (success) {
+                setString("migrated_keystore_namespace", "true", 0);
+                Slog.i(TAG, "Migrated keys to LSS namespace");
+            } else {
+                Slog.w(TAG, "Failed to migrate keys to LSS namespace");
+            }
+        }
+
     }
 
     private void migrateOldDataAfterSystemReady() {
@@ -995,6 +1022,22 @@ public class LockSettingsService extends ILockSettings.Stub {
         }
     }
 
+    private boolean migrateProfileLockKeys() {
+        boolean success = true;
+        final List<UserInfo> users = mUserManager.getUsers();
+        final int userCount = users.size();
+        for (int i = 0; i < userCount; i++) {
+            UserInfo user = users.get(i);
+            if (user.isManagedProfile() && !getSeparateProfileChallengeEnabledInternal(user.id)) {
+                success &= SyntheticPasswordCrypto.migrateLockSettingsKey(
+                        PROFILE_KEY_NAME_ENCRYPT + user.id);
+                success &= SyntheticPasswordCrypto.migrateLockSettingsKey(
+                        PROFILE_KEY_NAME_DECRYPT + user.id);
+            }
+        }
+        return success;
+    }
+
     /**
      * Returns the lowest password quality that still presents the same UI for entering it.
      *
@@ -1286,11 +1329,8 @@ public class LockSettingsService extends ILockSettings.Stub {
         byte[] encryptedPassword = Arrays.copyOfRange(storedData, PROFILE_KEY_IV_SIZE,
                 storedData.length);
         byte[] decryptionResult;
-        java.security.KeyStore keyStore = java.security.KeyStore.getInstance(
+        SecretKey decryptionKey = (SecretKey) mJavaKeyStore.getKey(
-                SyntheticPasswordCrypto.androidKeystoreProviderName());
+                PROFILE_KEY_NAME_DECRYPT + userId, null);
-        keyStore.load(null);
-        SecretKey decryptionKey = (SecretKey) keyStore.getKey(
-                LockPatternUtils.PROFILE_KEY_NAME_DECRYPT + userId, null);
 
         Cipher cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
                 + KeyProperties.BLOCK_MODE_GCM + "/" + KeyProperties.ENCRYPTION_PADDING_NONE);
@@ -1880,30 +1920,26 @@ public class LockSettingsService extends ILockSettings.Stub {
             KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES);
             keyGenerator.init(new SecureRandom());
             SecretKey secretKey = keyGenerator.generateKey();
-            java.security.KeyStore keyStore = java.security.KeyStore.getInstance(
-                    SyntheticPasswordCrypto.androidKeystoreProviderName());
-            keyStore.load(null);
             try {
-                keyStore.setEntry(
+                mJavaKeyStore.setEntry(
-                        LockPatternUtils.PROFILE_KEY_NAME_ENCRYPT + userId,
+                        PROFILE_KEY_NAME_ENCRYPT + userId,
                         new java.security.KeyStore.SecretKeyEntry(secretKey),
                         new KeyProtection.Builder(KeyProperties.PURPOSE_ENCRYPT)
                                 .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
                                 .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
                                 .build());
-                keyStore.setEntry(
+                mJavaKeyStore.setEntry(
-                        LockPatternUtils.PROFILE_KEY_NAME_DECRYPT + userId,
+                        PROFILE_KEY_NAME_DECRYPT + userId,
                         new java.security.KeyStore.SecretKeyEntry(secretKey),
                         new KeyProtection.Builder(KeyProperties.PURPOSE_DECRYPT)
                                 .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
                                 .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
                                 .setUserAuthenticationRequired(true)
                                 .setUserAuthenticationValidityDurationSeconds(30)
-                                .setCriticalToDeviceEncryption(true)
                                 .build());
                 // Key imported, obtain a reference to it.
-                SecretKey keyStoreEncryptionKey = (SecretKey) keyStore.getKey(
+                SecretKey keyStoreEncryptionKey = (SecretKey) mJavaKeyStore.getKey(
-                        LockPatternUtils.PROFILE_KEY_NAME_ENCRYPT + userId, null);
+                        PROFILE_KEY_NAME_ENCRYPT + userId, null);
                 Cipher cipher = Cipher.getInstance(
                         KeyProperties.KEY_ALGORITHM_AES + "/" + KeyProperties.BLOCK_MODE_GCM + "/"
                                 + KeyProperties.ENCRYPTION_PADDING_NONE);
@@ -1912,10 +1948,10 @@ public class LockSettingsService extends ILockSettings.Stub {
                 iv = cipher.getIV();
             } finally {
                 // The original key can now be discarded.
-                keyStore.deleteEntry(LockPatternUtils.PROFILE_KEY_NAME_ENCRYPT + userId);
+                mJavaKeyStore.deleteEntry(PROFILE_KEY_NAME_ENCRYPT + userId);
             }
-        } catch (CertificateException | UnrecoverableKeyException
+        } catch (UnrecoverableKeyException
-                | IOException | BadPaddingException | IllegalBlockSizeException | KeyStoreException
+                | BadPaddingException | IllegalBlockSizeException | KeyStoreException
                 | NoSuchPaddingException | NoSuchAlgorithmException | InvalidKeyException e) {
             throw new IllegalStateException("Failed to encrypt key", e);
         }
@@ -2460,13 +2496,9 @@ public class LockSettingsService extends ILockSettings.Stub {
     private void removeKeystoreProfileKey(int targetUserId) {
         Slog.i(TAG, "Remove keystore profile key for user: " + targetUserId);
         try {
-            java.security.KeyStore keyStore = java.security.KeyStore.getInstance(
+            mJavaKeyStore.deleteEntry(PROFILE_KEY_NAME_ENCRYPT + targetUserId);
-                    SyntheticPasswordCrypto.androidKeystoreProviderName());
+            mJavaKeyStore.deleteEntry(PROFILE_KEY_NAME_DECRYPT + targetUserId);
-            keyStore.load(null);
+        } catch (KeyStoreException e) {
-            keyStore.deleteEntry(LockPatternUtils.PROFILE_KEY_NAME_ENCRYPT + targetUserId);
-            keyStore.deleteEntry(LockPatternUtils.PROFILE_KEY_NAME_DECRYPT + targetUserId);
-        } catch (KeyStoreException | NoSuchAlgorithmException | CertificateException
-                | IOException e) {
             // We have tried our best to remove all keys
             Slog.e(TAG, "Unable to remove keystore profile key for user:" + targetUserId, e);
         }
@@ -3420,6 +3452,12 @@ public class LockSettingsService extends ILockSettings.Stub {
         pw.println();
         pw.decreaseIndent();
 
+        pw.println("Keys in namespace:");
+        pw.increaseIndent();
+        dumpKeystoreKeys(pw);
+        pw.println();
+        pw.decreaseIndent();
+
         pw.println("Storage:");
         pw.increaseIndent();
         mStorage.dump(pw);
@@ -3441,6 +3479,18 @@ public class LockSettingsService extends ILockSettings.Stub {
         pw.println("PasswordHandleCount: " + mGatekeeperPasswords.size());
     }
 
+    private void dumpKeystoreKeys(IndentingPrintWriter pw) {
+        try {
+            final Enumeration<String> aliases = mJavaKeyStore.aliases();
+            while (aliases.hasMoreElements()) {
+                pw.println(aliases.nextElement());
+            }
+        } catch (KeyStoreException e) {
+            pw.println("Unable to get keys: " + e.toString());
+            Slog.d(TAG, "Dump error", e);
+        }
+    }
+
     /**
      * Cryptographically disable escrow token support for the current user, if the user is not
      * managed (either user has a profile owner, or if device is managed). Do not disable

services/core/java/com/android/server/locksettings/ManagedProfilePasswordCache.java

@@ -23,7 +23,6 @@ import android.os.UserManager;
 import android.security.keystore.KeyGenParameterSpec;
 import android.security.keystore.KeyProperties;
 import android.security.keystore.UserNotAuthenticatedException;
-import android.security.keystore2.AndroidKeyStoreSpi;
 import android.util.Slog;
 import android.util.SparseArray;
 
@@ -95,11 +94,12 @@ public class ManagedProfilePasswordCache {
             SecretKey key;
             try {
                 generator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES,
-                        AndroidKeyStoreSpi.NAME);
+                        mKeyStore.getProvider());
                 generator.init(new KeyGenParameterSpec.Builder(
                         keyName, KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
                         .setKeySize(KEY_LENGTH)
                         .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
+                        .setNamespace(SyntheticPasswordCrypto.keyNamespace())
                         .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
                         // Generate auth-bound key to user 0 (since we the caller is user 0)
                         .setUserAuthenticationRequired(true)

services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java

@@ -16,8 +16,12 @@
 
 package com.android.server.locksettings;
 
+import android.security.AndroidKeyStoreMaintenance;
 import android.security.keystore.KeyProperties;
 import android.security.keystore.KeyProtection;
+import android.security.keystore2.AndroidKeyStoreLoadStoreParameter;
+import android.system.keystore2.Domain;
+import android.system.keystore2.KeyDescriptor;
 import android.util.Slog;
 
 import java.io.ByteArrayOutputStream;
@@ -125,9 +129,7 @@ public class SyntheticPasswordCrypto {
 
     public static byte[] decryptBlobV1(String keyAlias, byte[] blob, byte[] applicationId) {
         try {
-            KeyStore keyStore = KeyStore.getInstance(androidKeystoreProviderName());
+            KeyStore keyStore = getKeyStore();
-            keyStore.load(null);
-
             SecretKey decryptionKey = (SecretKey) keyStore.getKey(keyAlias, null);
             if (decryptionKey == null) {
                 throw new IllegalStateException("SP key is missing: " + keyAlias);
@@ -144,10 +146,20 @@ public class SyntheticPasswordCrypto {
         return "AndroidKeyStore";
     }
 
+    static int keyNamespace() {
+        return KeyProperties.NAMESPACE_LOCKSETTINGS;
+    }
+
+    private static KeyStore getKeyStore()
+            throws KeyStoreException, CertificateException, NoSuchAlgorithmException, IOException {
+        KeyStore keyStore = KeyStore.getInstance(androidKeystoreProviderName());
+        keyStore.load(new AndroidKeyStoreLoadStoreParameter(keyNamespace()));
+        return keyStore;
+    }
+
     public static byte[] decryptBlob(String keyAlias, byte[] blob, byte[] applicationId) {
         try {
-            KeyStore keyStore = KeyStore.getInstance(androidKeystoreProviderName());
+            final KeyStore keyStore = getKeyStore();
-            keyStore.load(null);
 
             SecretKey decryptionKey = (SecretKey) keyStore.getKey(keyAlias, null);
             if (decryptionKey == null) {
@@ -170,8 +182,7 @@ public class SyntheticPasswordCrypto {
             KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES);
             keyGenerator.init(AES_KEY_LENGTH * 8, new SecureRandom());
             SecretKey secretKey = keyGenerator.generateKey();
-            KeyStore keyStore = KeyStore.getInstance(androidKeystoreProviderName());
+            final KeyStore keyStore = getKeyStore();
-            keyStore.load(null);
             KeyProtection.Builder builder = new KeyProtection.Builder(KeyProperties.PURPOSE_DECRYPT)
                     .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
                     .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
@@ -200,8 +211,7 @@ public class SyntheticPasswordCrypto {
     public static void destroyBlobKey(String keyAlias) {
         KeyStore keyStore;
         try {
-            keyStore = KeyStore.getInstance(androidKeystoreProviderName());
+            keyStore = getKeyStore();
-            keyStore.load(null);
             keyStore.deleteEntry(keyAlias);
             Slog.i(TAG, "SP key deleted: " + keyAlias);
         } catch (KeyStoreException | NoSuchAlgorithmException | CertificateException
@@ -229,4 +239,32 @@ public class SyntheticPasswordCrypto {
             throw new IllegalStateException("NoSuchAlgorithmException for SHA-512", e);
         }
     }
+
+    static boolean migrateLockSettingsKey(String alias) {
+        final KeyDescriptor legacyKey = new KeyDescriptor();
+        legacyKey.domain = Domain.APP;
+        legacyKey.nspace = KeyProperties.NAMESPACE_APPLICATION;
+        legacyKey.alias = alias;
+
+        final KeyDescriptor newKey = new KeyDescriptor();
+        newKey.domain = Domain.SELINUX;
+        newKey.nspace = SyntheticPasswordCrypto.keyNamespace();
+        newKey.alias = alias;
+        Slog.i(TAG, "Migrating key " + alias);
+        int err = AndroidKeyStoreMaintenance.migrateKeyNamespace(legacyKey, newKey);
+        if (err == 0) {
+            return true;
+        } else if (err == AndroidKeyStoreMaintenance.KEY_NOT_FOUND) {
+            Slog.i(TAG, "Key does not exist");
+            // Treat this as a success so we don't migrate again.
+            return true;
+        } else if (err == AndroidKeyStoreMaintenance.INVALID_ARGUMENT) {
+            Slog.i(TAG, "Key already exists");
+            // Treat this as a success so we don't migrate again.
+            return true;
+        } else {
+            Slog.e(TAG, String.format("Failed to migrate key: %d", err));
+            return false;
+        }
+    }
 }

services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java

@@ -522,7 +522,7 @@ public class SyntheticPasswordManager {
     public void removeUser(int userId) {
         for (long handle : mStorage.listSyntheticPasswordHandlesForUser(SP_BLOB_NAME, userId)) {
             destroyWeaverSlot(handle, userId);
-            destroySPBlobKey(getHandleName(handle));
+            destroySPBlobKey(getKeyName(handle));
         }
     }
 
@@ -958,7 +958,7 @@ public class SyntheticPasswordManager {
         } else {
             secret = authToken.getSyntheticPassword();
         }
-        byte[] content = createSPBlob(getHandleName(handle), secret, applicationId, sid);
+        byte[] content = createSPBlob(getKeyName(handle), secret, applicationId, sid);
         byte[] blob = new byte[content.length + 1 + 1];
         /*
          * We can upgrade from v1 to v2 because that's just a change in the way that
@@ -1141,10 +1141,10 @@ public class SyntheticPasswordManager {
         }
         final byte[] secret;
         if (version == SYNTHETIC_PASSWORD_VERSION_V1) {
-            secret = SyntheticPasswordCrypto.decryptBlobV1(getHandleName(handle),
+            secret = SyntheticPasswordCrypto.decryptBlobV1(getKeyName(handle),
                     Arrays.copyOfRange(blob, 2, blob.length), applicationId);
         } else {
-            secret = decryptSPBlob(getHandleName(handle),
+            secret = decryptSPBlob(getKeyName(handle),
                 Arrays.copyOfRange(blob, 2, blob.length), applicationId);
         }
         if (secret == null) {
@@ -1247,7 +1247,7 @@ public class SyntheticPasswordManager {
 
     private void destroySyntheticPassword(long handle, int userId) {
         destroyState(SP_BLOB_NAME, handle, userId);
-        destroySPBlobKey(getHandleName(handle));
+        destroySPBlobKey(getKeyName(handle));
         if (hasState(WEAVER_SLOT_NAME, handle, userId)) {
             destroyWeaverSlot(handle, userId);
         }
@@ -1363,7 +1363,7 @@ public class SyntheticPasswordManager {
         }
     }
 
-    private String getHandleName(long handle) {
+    private String getKeyName(long handle) {
         return String.format("%s%x", LockPatternUtils.SYNTHETIC_PASSWORD_KEY_PREFIX, handle);
     }
 
@@ -1424,4 +1424,19 @@ public class SyntheticPasswordManager {
         }
         return hexBytes;
     }
+
+    /**
+     * Migrate all existing SP keystore keys from uid 1000 app domain to LSS selinux domain
+     */
+    public boolean migrateKeyNamespace() {
+        boolean success = true;
+        final Map<Integer, List<Long>> allHandles =
+                mStorage.listSyntheticPasswordHandlesForAllUsers(SP_BLOB_NAME);
+        for (List<Long> userHandles : allHandles.values()) {
+            for (long handle : userHandles) {
+                success &= SyntheticPasswordCrypto.migrateLockSettingsKey(getKeyName(handle));
+            }
+        }
+        return success;
+    }
 }

services/tests/servicestests/src/com/android/server/locksettings/LockSettingsServiceTestable.java

@@ -155,7 +155,8 @@ public class LockSettingsServiceTestable extends LockSettingsService {
         }
 
         @Override
-        public ManagedProfilePasswordCache getManagedProfilePasswordCache() {
+        public ManagedProfilePasswordCache getManagedProfilePasswordCache(
+                java.security.KeyStore ks) {
             return mock(ManagedProfilePasswordCache.class);
         }