| /* |
| * Copyright (C) 2017 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.recoverablekeystore; |
| |
| import static android.security.keystore.recovery.RecoveryController.ERROR_BAD_CERTIFICATE_FORMAT; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_DECRYPTION_FAILED; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_DOWNGRADE_CERTIFICATE; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_INSECURE_USER; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_INVALID_CERTIFICATE; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_INVALID_KEY_FORMAT; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_NO_SNAPSHOT_PENDING; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_SERVICE_INTERNAL_ERROR; |
| import static android.security.keystore.recovery.RecoveryController.ERROR_SESSION_EXPIRED; |
| |
| import android.Manifest; |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.app.PendingIntent; |
| import android.content.Context; |
| import android.os.Binder; |
| import android.os.RemoteException; |
| import android.os.ServiceSpecificException; |
| import android.os.UserHandle; |
| import android.security.KeyStore; |
| import android.security.keystore.recovery.KeyChainProtectionParams; |
| import android.security.keystore.recovery.KeyChainSnapshot; |
| import android.security.keystore.recovery.RecoveryCertPath; |
| import android.security.keystore.recovery.RecoveryController; |
| import android.security.keystore.recovery.WrappedApplicationKey; |
| import android.util.ArrayMap; |
| import android.util.Log; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.HexDump; |
| import com.android.internal.util.Preconditions; |
| import com.android.server.locksettings.recoverablekeystore.certificate.CertParsingException; |
| import com.android.server.locksettings.recoverablekeystore.certificate.CertUtils; |
| import com.android.server.locksettings.recoverablekeystore.certificate.CertValidationException; |
| import com.android.server.locksettings.recoverablekeystore.certificate.CertXml; |
| import com.android.server.locksettings.recoverablekeystore.certificate.SigXml; |
| import com.android.server.locksettings.recoverablekeystore.storage.ApplicationKeyStorage; |
| import com.android.server.locksettings.recoverablekeystore.storage.CleanupManager; |
| import com.android.server.locksettings.recoverablekeystore.storage.RecoverableKeyStoreDb; |
| import com.android.server.locksettings.recoverablekeystore.storage.RecoverySessionStorage; |
| import com.android.server.locksettings.recoverablekeystore.storage.RecoverySnapshotStorage; |
| |
| import java.io.IOException; |
| import java.security.InvalidKeyException; |
| import java.security.KeyStoreException; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.PublicKey; |
| import java.security.SecureRandom; |
| import java.security.UnrecoverableKeyException; |
| import java.security.cert.CertPath; |
| import java.security.cert.CertificateEncodingException; |
| import java.security.cert.CertificateException; |
| import java.security.cert.X509Certificate; |
| import java.security.spec.InvalidKeySpecException; |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Locale; |
| import java.util.Map; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| |
| import javax.crypto.AEADBadTagException; |
| |
| /** |
| * Class with {@link RecoveryController} API implementation and internal methods to interact |
| * with {@code LockSettingsService}. |
| * |
| * @hide |
| */ |
| public class RecoverableKeyStoreManager { |
| private static final String TAG = "RecoverableKeyStoreMgr"; |
| |
| private static RecoverableKeyStoreManager mInstance; |
| |
| private final Context mContext; |
| private final RecoverableKeyStoreDb mDatabase; |
| private final RecoverySessionStorage mRecoverySessionStorage; |
| private final ExecutorService mExecutorService; |
| private final RecoverySnapshotListenersStorage mListenersStorage; |
| private final RecoverableKeyGenerator mRecoverableKeyGenerator; |
| private final RecoverySnapshotStorage mSnapshotStorage; |
| private final PlatformKeyManager mPlatformKeyManager; |
| private final ApplicationKeyStorage mApplicationKeyStorage; |
| private final TestOnlyInsecureCertificateHelper mTestCertHelper; |
| private final CleanupManager mCleanupManager; |
| |
| /** |
| * Returns a new or existing instance. |
| * |
| * @hide |
| */ |
| public static synchronized RecoverableKeyStoreManager |
| getInstance(Context context, KeyStore keystore) { |
| if (mInstance == null) { |
| RecoverableKeyStoreDb db = RecoverableKeyStoreDb.newInstance(context); |
| PlatformKeyManager platformKeyManager; |
| ApplicationKeyStorage applicationKeyStorage; |
| try { |
| platformKeyManager = PlatformKeyManager.getInstance(context, db); |
| applicationKeyStorage = ApplicationKeyStorage.getInstance(keystore); |
| } catch (NoSuchAlgorithmException e) { |
| // Impossible: all algorithms must be supported by AOSP |
| throw new RuntimeException(e); |
| } catch (KeyStoreException e) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } |
| |
| RecoverySnapshotStorage snapshotStorage = |
| RecoverySnapshotStorage.newInstance(); |
| CleanupManager cleanupManager = CleanupManager.getInstance( |
| context.getApplicationContext(), |
| snapshotStorage, |
| db, |
| applicationKeyStorage); |
| mInstance = new RecoverableKeyStoreManager( |
| context.getApplicationContext(), |
| db, |
| new RecoverySessionStorage(), |
| Executors.newSingleThreadExecutor(), |
| snapshotStorage, |
| new RecoverySnapshotListenersStorage(), |
| platformKeyManager, |
| applicationKeyStorage, |
| new TestOnlyInsecureCertificateHelper(), |
| cleanupManager); |
| } |
| return mInstance; |
| } |
| |
| @VisibleForTesting |
| RecoverableKeyStoreManager( |
| Context context, |
| RecoverableKeyStoreDb recoverableKeyStoreDb, |
| RecoverySessionStorage recoverySessionStorage, |
| ExecutorService executorService, |
| RecoverySnapshotStorage snapshotStorage, |
| RecoverySnapshotListenersStorage listenersStorage, |
| PlatformKeyManager platformKeyManager, |
| ApplicationKeyStorage applicationKeyStorage, |
| TestOnlyInsecureCertificateHelper testOnlyInsecureCertificateHelper, |
| CleanupManager cleanupManager) { |
| mContext = context; |
| mDatabase = recoverableKeyStoreDb; |
| mRecoverySessionStorage = recoverySessionStorage; |
| mExecutorService = executorService; |
| mListenersStorage = listenersStorage; |
| mSnapshotStorage = snapshotStorage; |
| mPlatformKeyManager = platformKeyManager; |
| mApplicationKeyStorage = applicationKeyStorage; |
| mTestCertHelper = testOnlyInsecureCertificateHelper; |
| mCleanupManager = cleanupManager; |
| // Clears data for removed users. |
| mCleanupManager.verifyKnownUsers(); |
| try { |
| mRecoverableKeyGenerator = RecoverableKeyGenerator.newInstance(mDatabase); |
| } catch (NoSuchAlgorithmException e) { |
| Log.wtf(TAG, "AES keygen algorithm not available. AOSP must support this.", e); |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } |
| } |
| |
| /** |
| * Used by {@link #initRecoveryServiceWithSigFile(String, byte[], byte[])}. |
| */ |
| @VisibleForTesting |
| void initRecoveryService( |
| @NonNull String rootCertificateAlias, @NonNull byte[] recoveryServiceCertFile) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| int userId = UserHandle.getCallingUserId(); |
| int uid = Binder.getCallingUid(); |
| |
| rootCertificateAlias |
| = mTestCertHelper.getDefaultCertificateAliasIfEmpty(rootCertificateAlias); |
| if (!mTestCertHelper.isValidRootCertificateAlias(rootCertificateAlias)) { |
| throw new ServiceSpecificException( |
| ERROR_INVALID_CERTIFICATE, "Invalid root certificate alias"); |
| } |
| // Always set active alias to the argument of the last call to initRecoveryService method, |
| // even if cert file is incorrect. |
| String activeRootAlias = mDatabase.getActiveRootOfTrust(userId, uid); |
| if (activeRootAlias == null) { |
| Log.d(TAG, "Root of trust for recovery agent + " + uid |
| + " is assigned for the first time to " + rootCertificateAlias); |
| } else if (!activeRootAlias.equals(rootCertificateAlias)) { |
| Log.i(TAG, "Root of trust for recovery agent " + uid + " is changed to " |
| + rootCertificateAlias + " from " + activeRootAlias); |
| } |
| long updatedRows = mDatabase.setActiveRootOfTrust(userId, uid, rootCertificateAlias); |
| if (updatedRows < 0) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, |
| "Failed to set the root of trust in the local DB."); |
| } |
| |
| CertXml certXml; |
| try { |
| certXml = CertXml.parse(recoveryServiceCertFile); |
| } catch (CertParsingException e) { |
| Log.d(TAG, "Failed to parse the input as a cert file: " + HexDump.toHexString( |
| recoveryServiceCertFile)); |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, e.getMessage()); |
| } |
| |
| // Check serial number |
| long newSerial = certXml.getSerial(); |
| Long oldSerial = mDatabase.getRecoveryServiceCertSerial(userId, uid, rootCertificateAlias); |
| if (oldSerial != null && oldSerial >= newSerial |
| && !mTestCertHelper.isTestOnlyCertificateAlias(rootCertificateAlias)) { |
| if (oldSerial == newSerial) { |
| Log.i(TAG, "The cert file serial number is the same, so skip updating."); |
| } else { |
| Log.e(TAG, "The cert file serial number is older than the one in database."); |
| throw new ServiceSpecificException(ERROR_DOWNGRADE_CERTIFICATE, |
| "The cert file serial number is older than the one in database."); |
| } |
| return; |
| } |
| Log.i(TAG, "Updating the certificate with the new serial number " + newSerial); |
| |
| // Randomly choose and validate an endpoint certificate from the list |
| CertPath certPath; |
| X509Certificate rootCert = |
| mTestCertHelper.getRootCertificate(rootCertificateAlias); |
| try { |
| Log.d(TAG, "Getting and validating a random endpoint certificate"); |
| certPath = certXml.getRandomEndpointCert(rootCert); |
| } catch (CertValidationException e) { |
| Log.e(TAG, "Invalid endpoint cert", e); |
| throw new ServiceSpecificException(ERROR_INVALID_CERTIFICATE, e.getMessage()); |
| } |
| |
| // Save the chosen and validated certificate into database |
| try { |
| Log.d(TAG, "Saving the randomly chosen endpoint certificate to database"); |
| long updatedCertPathRows = mDatabase.setRecoveryServiceCertPath(userId, uid, |
| rootCertificateAlias, certPath); |
| if (updatedCertPathRows > 0) { |
| long updatedCertSerialRows = mDatabase.setRecoveryServiceCertSerial(userId, uid, |
| rootCertificateAlias, newSerial); |
| if (updatedCertSerialRows < 0) { |
| // Ideally CertPath and CertSerial should be updated together in single |
| // transaction, but since their mismatch doesn't create many problems |
| // extra complexity is unnecessary. |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, |
| "Failed to set the certificate serial number in the local DB."); |
| } |
| if (mDatabase.getSnapshotVersion(userId, uid) != null) { |
| mDatabase.setShouldCreateSnapshot(userId, uid, true); |
| Log.i(TAG, "This is a certificate change. Snapshot must be updated"); |
| } else { |
| Log.i(TAG, "This is a certificate change. Snapshot didn't exist"); |
| } |
| long updatedCounterIdRows = |
| mDatabase.setCounterId(userId, uid, new SecureRandom().nextLong()); |
| if (updatedCounterIdRows < 0) { |
| Log.e(TAG, "Failed to set the counter id in the local DB."); |
| } |
| } else if (updatedCertPathRows < 0) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, |
| "Failed to set the certificate path in the local DB."); |
| } |
| } catch (CertificateEncodingException e) { |
| Log.e(TAG, "Failed to encode CertPath", e); |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, e.getMessage()); |
| } |
| } |
| |
| /** |
| * Initializes the recovery service with the two files {@code recoveryServiceCertFile} and |
| * {@code recoveryServiceSigFile}. |
| * |
| * @param rootCertificateAlias the alias for the root certificate that is used for validating |
| * the recovery service certificates. |
| * @param recoveryServiceCertFile the content of the XML file containing a list of certificates |
| * for the recovery service. |
| * @param recoveryServiceSigFile the content of the XML file containing the public-key signature |
| * over the entire content of {@code recoveryServiceCertFile}. |
| */ |
| public void initRecoveryServiceWithSigFile( |
| @NonNull String rootCertificateAlias, @NonNull byte[] recoveryServiceCertFile, |
| @NonNull byte[] recoveryServiceSigFile) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| rootCertificateAlias = |
| mTestCertHelper.getDefaultCertificateAliasIfEmpty(rootCertificateAlias); |
| Preconditions.checkNotNull(recoveryServiceCertFile, "recoveryServiceCertFile is null"); |
| Preconditions.checkNotNull(recoveryServiceSigFile, "recoveryServiceSigFile is null"); |
| |
| SigXml sigXml; |
| try { |
| sigXml = SigXml.parse(recoveryServiceSigFile); |
| } catch (CertParsingException e) { |
| Log.d(TAG, "Failed to parse the sig file: " + HexDump.toHexString( |
| recoveryServiceSigFile)); |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, e.getMessage()); |
| } |
| |
| X509Certificate rootCert = |
| mTestCertHelper.getRootCertificate(rootCertificateAlias); |
| try { |
| sigXml.verifyFileSignature(rootCert, recoveryServiceCertFile); |
| } catch (CertValidationException e) { |
| Log.d(TAG, "The signature over the cert file is invalid." |
| + " Cert: " + HexDump.toHexString(recoveryServiceCertFile) |
| + " Sig: " + HexDump.toHexString(recoveryServiceSigFile)); |
| throw new ServiceSpecificException(ERROR_INVALID_CERTIFICATE, e.getMessage()); |
| } |
| |
| initRecoveryService(rootCertificateAlias, recoveryServiceCertFile); |
| } |
| |
| /** |
| * Gets all data necessary to recover application keys on new device. |
| * |
| * @return KeyChain Snapshot. |
| * @throws ServiceSpecificException if no snapshot is pending. |
| * @hide |
| */ |
| public @NonNull KeyChainSnapshot getKeyChainSnapshot() |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| int uid = Binder.getCallingUid(); |
| KeyChainSnapshot snapshot = mSnapshotStorage.get(uid); |
| if (snapshot == null) { |
| throw new ServiceSpecificException(ERROR_NO_SNAPSHOT_PENDING); |
| } |
| return snapshot; |
| } |
| |
| public void setSnapshotCreatedPendingIntent(@Nullable PendingIntent intent) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| int uid = Binder.getCallingUid(); |
| mListenersStorage.setSnapshotListener(uid, intent); |
| } |
| |
| /** |
| * Set the server params for the user's key chain. This is used to uniquely identify a key |
| * chain. Along with the counter ID, it is used to uniquely identify an instance of a vault. |
| */ |
| public void setServerParams(@NonNull byte[] serverParams) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| int userId = UserHandle.getCallingUserId(); |
| int uid = Binder.getCallingUid(); |
| |
| byte[] currentServerParams = mDatabase.getServerParams(userId, uid); |
| |
| if (Arrays.equals(serverParams, currentServerParams)) { |
| Log.v(TAG, "Not updating server params - same as old value."); |
| return; |
| } |
| |
| long updatedRows = mDatabase.setServerParams(userId, uid, serverParams); |
| if (updatedRows < 0) { |
| throw new ServiceSpecificException( |
| ERROR_SERVICE_INTERNAL_ERROR, "Database failure trying to set server params."); |
| } |
| |
| if (currentServerParams == null) { |
| Log.i(TAG, "Initialized server params."); |
| return; |
| } |
| |
| if (mDatabase.getSnapshotVersion(userId, uid) != null) { |
| mDatabase.setShouldCreateSnapshot(userId, uid, true); |
| Log.i(TAG, "Updated server params. Snapshot must be updated"); |
| } else { |
| Log.i(TAG, "Updated server params. Snapshot didn't exist"); |
| } |
| } |
| |
| /** |
| * Sets the recovery status of key with {@code alias} to {@code status}. |
| */ |
| public void setRecoveryStatus(@NonNull String alias, int status) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(alias, "alias is null"); |
| long updatedRows = mDatabase.setRecoveryStatus(Binder.getCallingUid(), alias, status); |
| if (updatedRows < 0) { |
| throw new ServiceSpecificException( |
| ERROR_SERVICE_INTERNAL_ERROR, |
| "Failed to set the key recovery status in the local DB."); |
| } |
| } |
| |
| /** |
| * Returns recovery statuses for all keys belonging to the calling uid. |
| * |
| * @return {@link Map} from key alias to recovery status. Recovery status is one of |
| * {@link RecoveryController#RECOVERY_STATUS_SYNCED}, |
| * {@link RecoveryController#RECOVERY_STATUS_SYNC_IN_PROGRESS} or |
| * {@link RecoveryController#RECOVERY_STATUS_PERMANENT_FAILURE}. |
| */ |
| public @NonNull Map<String, Integer> getRecoveryStatus() throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| return mDatabase.getStatusForAllKeys(Binder.getCallingUid()); |
| } |
| |
| /** |
| * Sets recovery secrets list used by all recovery agents for given {@code userId} |
| * |
| * @hide |
| */ |
| public void setRecoverySecretTypes( |
| @NonNull @KeyChainProtectionParams.UserSecretType int[] secretTypes) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(secretTypes, "secretTypes is null"); |
| int userId = UserHandle.getCallingUserId(); |
| int uid = Binder.getCallingUid(); |
| |
| int[] currentSecretTypes = mDatabase.getRecoverySecretTypes(userId, uid); |
| if (Arrays.equals(secretTypes, currentSecretTypes)) { |
| Log.v(TAG, "Not updating secret types - same as old value."); |
| return; |
| } |
| |
| long updatedRows = mDatabase.setRecoverySecretTypes(userId, uid, secretTypes); |
| if (updatedRows < 0) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, |
| "Database error trying to set secret types."); |
| } |
| |
| if (currentSecretTypes.length == 0) { |
| Log.i(TAG, "Initialized secret types."); |
| return; |
| } |
| |
| Log.i(TAG, "Updated secret types. Snapshot pending."); |
| if (mDatabase.getSnapshotVersion(userId, uid) != null) { |
| mDatabase.setShouldCreateSnapshot(userId, uid, true); |
| Log.i(TAG, "Updated secret types. Snapshot must be updated"); |
| } else { |
| Log.i(TAG, "Updated secret types. Snapshot didn't exist"); |
| } |
| } |
| |
| /** |
| * Gets secret types necessary to create Recovery Data. |
| * |
| * @return secret types |
| * @hide |
| */ |
| public @NonNull int[] getRecoverySecretTypes() throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| return mDatabase.getRecoverySecretTypes(UserHandle.getCallingUserId(), |
| Binder.getCallingUid()); |
| } |
| |
| /** |
| * Initializes recovery session given the X509-encoded public key of the recovery service. |
| * |
| * @param sessionId A unique ID to identify the recovery session. |
| * @param verifierPublicKey X509-encoded public key. |
| * @param vaultParams Additional params associated with vault. |
| * @param vaultChallenge Challenge issued by vault service. |
| * @param secrets Lock-screen hashes. For now only a single secret is supported. |
| * @return Encrypted bytes of recovery claim. This can then be issued to the vault service. |
| * @deprecated Use {@link #startRecoverySessionWithCertPath(String, String, RecoveryCertPath, |
| * byte[], byte[], List)} instead. |
| * |
| * @hide |
| */ |
| @VisibleForTesting |
| @NonNull byte[] startRecoverySession( |
| @NonNull String sessionId, |
| @NonNull byte[] verifierPublicKey, |
| @NonNull byte[] vaultParams, |
| @NonNull byte[] vaultChallenge, |
| @NonNull List<KeyChainProtectionParams> secrets) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| int uid = Binder.getCallingUid(); |
| |
| if (secrets.size() != 1) { |
| throw new UnsupportedOperationException( |
| "Only a single KeyChainProtectionParams is supported"); |
| } |
| |
| PublicKey publicKey; |
| try { |
| publicKey = KeySyncUtils.deserializePublicKey(verifierPublicKey); |
| } catch (InvalidKeySpecException e) { |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, e.getMessage()); |
| } |
| // The raw public key bytes contained in vaultParams must match the ones given in |
| // verifierPublicKey; otherwise, the user secret may be decrypted by a key that is not owned |
| // by the original recovery service. |
| if (!publicKeysMatch(publicKey, vaultParams)) { |
| throw new ServiceSpecificException(ERROR_INVALID_CERTIFICATE, |
| "The public keys given in verifierPublicKey and vaultParams do not match."); |
| } |
| |
| byte[] keyClaimant = KeySyncUtils.generateKeyClaimant(); |
| byte[] kfHash = secrets.get(0).getSecret(); |
| mRecoverySessionStorage.add( |
| uid, |
| new RecoverySessionStorage.Entry(sessionId, kfHash, keyClaimant, vaultParams)); |
| |
| Log.i(TAG, "Received VaultParams for recovery: " + HexDump.toHexString(vaultParams)); |
| try { |
| byte[] thmKfHash = KeySyncUtils.calculateThmKfHash(kfHash); |
| return KeySyncUtils.encryptRecoveryClaim( |
| publicKey, |
| vaultParams, |
| vaultChallenge, |
| thmKfHash, |
| keyClaimant); |
| } catch (NoSuchAlgorithmException e) { |
| Log.wtf(TAG, "SecureBox algorithm missing. AOSP must support this.", e); |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } catch (InvalidKeyException e) { |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, e.getMessage()); |
| } |
| } |
| |
| /** |
| * Initializes recovery session given the certificate path of the recovery service. |
| * |
| * @param sessionId A unique ID to identify the recovery session. |
| * @param verifierCertPath The certificate path of the recovery service. |
| * @param vaultParams Additional params associated with vault. |
| * @param vaultChallenge Challenge issued by vault service. |
| * @param secrets Lock-screen hashes. For now only a single secret is supported. |
| * @return Encrypted bytes of recovery claim. This can then be issued to the vault service. |
| * |
| * @hide |
| */ |
| public @NonNull byte[] startRecoverySessionWithCertPath( |
| @NonNull String sessionId, |
| @NonNull String rootCertificateAlias, |
| @NonNull RecoveryCertPath verifierCertPath, |
| @NonNull byte[] vaultParams, |
| @NonNull byte[] vaultChallenge, |
| @NonNull List<KeyChainProtectionParams> secrets) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| rootCertificateAlias = |
| mTestCertHelper.getDefaultCertificateAliasIfEmpty(rootCertificateAlias); |
| Preconditions.checkNotNull(sessionId, "invalid session"); |
| Preconditions.checkNotNull(verifierCertPath, "verifierCertPath is null"); |
| Preconditions.checkNotNull(vaultParams, "vaultParams is null"); |
| Preconditions.checkNotNull(vaultChallenge, "vaultChallenge is null"); |
| Preconditions.checkNotNull(secrets, "secrets is null"); |
| CertPath certPath; |
| try { |
| certPath = verifierCertPath.getCertPath(); |
| } catch (CertificateException e) { |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, e.getMessage()); |
| } |
| |
| try { |
| CertUtils.validateCertPath( |
| mTestCertHelper.getRootCertificate(rootCertificateAlias), certPath); |
| } catch (CertValidationException e) { |
| Log.e(TAG, "Failed to validate the given cert path", e); |
| throw new ServiceSpecificException(ERROR_INVALID_CERTIFICATE, e.getMessage()); |
| } |
| |
| byte[] verifierPublicKey = certPath.getCertificates().get(0).getPublicKey().getEncoded(); |
| if (verifierPublicKey == null) { |
| Log.e(TAG, "Failed to encode verifierPublicKey"); |
| throw new ServiceSpecificException(ERROR_BAD_CERTIFICATE_FORMAT, |
| "Failed to encode verifierPublicKey"); |
| } |
| |
| return startRecoverySession( |
| sessionId, verifierPublicKey, vaultParams, vaultChallenge, secrets); |
| } |
| |
| /** |
| * Invoked by a recovery agent after a successful recovery claim is sent to the remote vault |
| * service. |
| * |
| * @param sessionId The session ID used to generate the claim. See |
| * {@link #startRecoverySession(String, byte[], byte[], byte[], List)}. |
| * @param encryptedRecoveryKey The encrypted recovery key blob returned by the remote vault |
| * service. |
| * @param applicationKeys The encrypted key blobs returned by the remote vault service. These |
| * were wrapped with the recovery key. |
| * @throws RemoteException if an error occurred recovering the keys. |
| */ |
| public @NonNull Map<String, String> recoverKeyChainSnapshot( |
| @NonNull String sessionId, |
| @NonNull byte[] encryptedRecoveryKey, |
| @NonNull List<WrappedApplicationKey> applicationKeys) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| int userId = UserHandle.getCallingUserId(); |
| int uid = Binder.getCallingUid(); |
| RecoverySessionStorage.Entry sessionEntry = mRecoverySessionStorage.get(uid, sessionId); |
| if (sessionEntry == null) { |
| throw new ServiceSpecificException(ERROR_SESSION_EXPIRED, |
| String.format(Locale.US, |
| "Application uid=%d does not have pending session '%s'", |
| uid, |
| sessionId)); |
| } |
| |
| try { |
| byte[] recoveryKey = decryptRecoveryKey(sessionEntry, encryptedRecoveryKey); |
| Map<String, byte[]> keysByAlias = recoverApplicationKeys(recoveryKey, |
| applicationKeys); |
| return importKeyMaterials(userId, uid, keysByAlias); |
| } catch (KeyStoreException e) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } finally { |
| sessionEntry.destroy(); |
| mRecoverySessionStorage.remove(uid); |
| } |
| } |
| |
| /** |
| * Imports the key materials, returning a map from alias to grant alias for the calling user. |
| * |
| * @param userId The calling user ID. |
| * @param uid The calling uid. |
| * @param keysByAlias The key materials, keyed by alias. |
| * @throws KeyStoreException if an error occurs importing the key or getting the grant. |
| */ |
| private @NonNull Map<String, String> importKeyMaterials( |
| int userId, int uid, Map<String, byte[]> keysByAlias) |
| throws KeyStoreException { |
| ArrayMap<String, String> grantAliasesByAlias = new ArrayMap<>(keysByAlias.size()); |
| for (String alias : keysByAlias.keySet()) { |
| mApplicationKeyStorage.setSymmetricKeyEntry(userId, uid, alias, keysByAlias.get(alias)); |
| String grantAlias = getAlias(userId, uid, alias); |
| Log.i(TAG, String.format(Locale.US, "Import %s -> %s", alias, grantAlias)); |
| grantAliasesByAlias.put(alias, grantAlias); |
| } |
| return grantAliasesByAlias; |
| } |
| |
| /** |
| * Returns an alias for the key. |
| * |
| * @param userId The user ID of the calling process. |
| * @param uid The uid of the calling process. |
| * @param alias The alias of the key. |
| * @return The alias in the calling process's keystore. |
| */ |
| private @Nullable String getAlias(int userId, int uid, String alias) { |
| return mApplicationKeyStorage.getGrantAlias(userId, uid, alias); |
| } |
| |
| /** |
| * Destroys the session with the given {@code sessionId}. |
| */ |
| public void closeSession(@NonNull String sessionId) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(sessionId, "invalid session"); |
| mRecoverySessionStorage.remove(Binder.getCallingUid(), sessionId); |
| } |
| |
| public void removeKey(@NonNull String alias) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(alias, "alias is null"); |
| int uid = Binder.getCallingUid(); |
| int userId = UserHandle.getCallingUserId(); |
| |
| boolean wasRemoved = mDatabase.removeKey(uid, alias); |
| if (wasRemoved) { |
| mDatabase.setShouldCreateSnapshot(userId, uid, true); |
| mApplicationKeyStorage.deleteEntry(userId, uid, alias); |
| } |
| } |
| |
| /** |
| * Generates a key named {@code alias} in caller's namespace. |
| * The key is stored in system service keystore namespace. |
| * |
| * @param alias the alias provided by caller as a reference to the key. |
| * @return grant alias, which caller can use to access the key. |
| * @throws RemoteException if certain internal errors occur. |
| * |
| * @deprecated Use {@link #generateKeyWithMetadata(String, byte[])} instead. |
| */ |
| @Deprecated |
| public String generateKey(@NonNull String alias) throws RemoteException { |
| return generateKeyWithMetadata(alias, /*metadata=*/ null); |
| } |
| |
| /** |
| * Generates a key named {@code alias} with the {@code metadata} in caller's namespace. |
| * The key is stored in system service keystore namespace. |
| * |
| * @param alias the alias provided by caller as a reference to the key. |
| * @param metadata the optional metadata blob that will authenticated (but unencrypted) together |
| * with the key material when the key is uploaded to cloud. |
| * @return grant alias, which caller can use to access the key. |
| * @throws RemoteException if certain internal errors occur. |
| */ |
| public String generateKeyWithMetadata(@NonNull String alias, @Nullable byte[] metadata) |
| throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(alias, "alias is null"); |
| int uid = Binder.getCallingUid(); |
| int userId = UserHandle.getCallingUserId(); |
| |
| PlatformEncryptionKey encryptionKey; |
| try { |
| encryptionKey = mPlatformKeyManager.getEncryptKey(userId); |
| } catch (NoSuchAlgorithmException e) { |
| // Impossible: all algorithms must be supported by AOSP |
| throw new RuntimeException(e); |
| } catch (KeyStoreException | UnrecoverableKeyException | IOException e) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } catch (InsecureUserException e) { |
| throw new ServiceSpecificException(ERROR_INSECURE_USER, e.getMessage()); |
| } |
| |
| try { |
| byte[] secretKey = mRecoverableKeyGenerator.generateAndStoreKey(encryptionKey, userId, |
| uid, alias, metadata); |
| mApplicationKeyStorage.setSymmetricKeyEntry(userId, uid, alias, secretKey); |
| return getAlias(userId, uid, alias); |
| } catch (KeyStoreException | InvalidKeyException | RecoverableKeyStorageException e) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } |
| } |
| |
| /** |
| * Imports a 256-bit AES-GCM key named {@code alias}. The key is stored in system service |
| * keystore namespace. |
| * |
| * @param alias the alias provided by caller as a reference to the key. |
| * @param keyBytes the raw bytes of the 256-bit AES key. |
| * @return grant alias, which caller can use to access the key. |
| * @throws RemoteException if the given key is invalid or some internal errors occur. |
| * |
| * @deprecated Use {{@link #importKeyWithMetadata(String, byte[], byte[])}} instead. |
| * |
| * @hide |
| */ |
| @Deprecated |
| public @Nullable String importKey(@NonNull String alias, @NonNull byte[] keyBytes) |
| throws RemoteException { |
| return importKeyWithMetadata(alias, keyBytes, /*metadata=*/ null); |
| } |
| |
| /** |
| * Imports a 256-bit AES-GCM key named {@code alias} with the given {@code metadata}. The key is |
| * stored in system service keystore namespace. |
| * |
| * @param alias the alias provided by caller as a reference to the key. |
| * @param keyBytes the raw bytes of the 256-bit AES key. |
| * @param metadata the metadata to be authenticated (but unencrypted) together with the key. |
| * @return grant alias, which caller can use to access the key. |
| * @throws RemoteException if the given key is invalid or some internal errors occur. |
| * |
| * @hide |
| */ |
| public @Nullable String importKeyWithMetadata(@NonNull String alias, @NonNull byte[] keyBytes, |
| @Nullable byte[] metadata) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(alias, "alias is null"); |
| Preconditions.checkNotNull(keyBytes, "keyBytes is null"); |
| if (keyBytes.length != RecoverableKeyGenerator.KEY_SIZE_BITS / Byte.SIZE) { |
| Log.e(TAG, "The given key for import doesn't have the required length " |
| + RecoverableKeyGenerator.KEY_SIZE_BITS); |
| throw new ServiceSpecificException(ERROR_INVALID_KEY_FORMAT, |
| "The given key does not contain " + RecoverableKeyGenerator.KEY_SIZE_BITS |
| + " bits."); |
| } |
| |
| int uid = Binder.getCallingUid(); |
| int userId = UserHandle.getCallingUserId(); |
| |
| PlatformEncryptionKey encryptionKey; |
| try { |
| encryptionKey = mPlatformKeyManager.getEncryptKey(userId); |
| } catch (NoSuchAlgorithmException e) { |
| // Impossible: all algorithms must be supported by AOSP |
| throw new RuntimeException(e); |
| } catch (KeyStoreException | UnrecoverableKeyException | IOException e) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } catch (InsecureUserException e) { |
| throw new ServiceSpecificException(ERROR_INSECURE_USER, e.getMessage()); |
| } |
| |
| try { |
| // Wrap the key by the platform key and store the wrapped key locally |
| mRecoverableKeyGenerator.importKey(encryptionKey, userId, uid, alias, keyBytes, |
| metadata); |
| |
| // Import the key to Android KeyStore and get grant |
| mApplicationKeyStorage.setSymmetricKeyEntry(userId, uid, alias, keyBytes); |
| return getAlias(userId, uid, alias); |
| } catch (KeyStoreException | InvalidKeyException | RecoverableKeyStorageException e) { |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } |
| } |
| |
| /** |
| * Gets a key named {@code alias} in caller's namespace. |
| * |
| * @return grant alias, which caller can use to access the key. |
| */ |
| public @Nullable String getKey(@NonNull String alias) throws RemoteException { |
| checkRecoverKeyStorePermission(); |
| Preconditions.checkNotNull(alias, "alias is null"); |
| int uid = Binder.getCallingUid(); |
| int userId = UserHandle.getCallingUserId(); |
| return getAlias(userId, uid, alias); |
| } |
| |
| private byte[] decryptRecoveryKey( |
| RecoverySessionStorage.Entry sessionEntry, byte[] encryptedClaimResponse) |
| throws RemoteException, ServiceSpecificException { |
| byte[] locallyEncryptedKey; |
| try { |
| locallyEncryptedKey = KeySyncUtils.decryptRecoveryClaimResponse( |
| sessionEntry.getKeyClaimant(), |
| sessionEntry.getVaultParams(), |
| encryptedClaimResponse); |
| } catch (InvalidKeyException e) { |
| Log.e(TAG, "Got InvalidKeyException during decrypting recovery claim response", e); |
| throw new ServiceSpecificException(ERROR_DECRYPTION_FAILED, |
| "Failed to decrypt recovery key " + e.getMessage()); |
| } catch (AEADBadTagException e) { |
| Log.e(TAG, "Got AEADBadTagException during decrypting recovery claim response", e); |
| throw new ServiceSpecificException(ERROR_DECRYPTION_FAILED, |
| "Failed to decrypt recovery key " + e.getMessage()); |
| } catch (NoSuchAlgorithmException e) { |
| // Should never happen: all the algorithms used are required by AOSP implementations |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } |
| |
| try { |
| return KeySyncUtils.decryptRecoveryKey(sessionEntry.getLskfHash(), locallyEncryptedKey); |
| } catch (InvalidKeyException e) { |
| Log.e(TAG, "Got InvalidKeyException during decrypting recovery key", e); |
| throw new ServiceSpecificException(ERROR_DECRYPTION_FAILED, |
| "Failed to decrypt recovery key " + e.getMessage()); |
| } catch (AEADBadTagException e) { |
| Log.e(TAG, "Got AEADBadTagException during decrypting recovery key", e); |
| throw new ServiceSpecificException(ERROR_DECRYPTION_FAILED, |
| "Failed to decrypt recovery key " + e.getMessage()); |
| } catch (NoSuchAlgorithmException e) { |
| // Should never happen: all the algorithms used are required by AOSP implementations |
| throw new ServiceSpecificException(ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } |
| } |
| |
| /** |
| * Uses {@code recoveryKey} to decrypt {@code applicationKeys}. |
| * |
| * @return Map from alias to raw key material. |
| * @throws RemoteException if an error occurred decrypting the keys. |
| */ |
| private @NonNull Map<String, byte[]> recoverApplicationKeys(@NonNull byte[] recoveryKey, |
| @NonNull List<WrappedApplicationKey> applicationKeys) throws RemoteException { |
| HashMap<String, byte[]> keyMaterialByAlias = new HashMap<>(); |
| for (WrappedApplicationKey applicationKey : applicationKeys) { |
| String alias = applicationKey.getAlias(); |
| byte[] encryptedKeyMaterial = applicationKey.getEncryptedKeyMaterial(); |
| byte[] keyMetadata = applicationKey.getMetadata(); |
| |
| try { |
| byte[] keyMaterial = KeySyncUtils.decryptApplicationKey(recoveryKey, |
| encryptedKeyMaterial, keyMetadata); |
| keyMaterialByAlias.put(alias, keyMaterial); |
| } catch (NoSuchAlgorithmException e) { |
| Log.wtf(TAG, "Missing SecureBox algorithm. AOSP required to support this.", e); |
| throw new ServiceSpecificException( |
| ERROR_SERVICE_INTERNAL_ERROR, e.getMessage()); |
| } catch (InvalidKeyException e) { |
| Log.e(TAG, "Got InvalidKeyException during decrypting application key with alias: " |
| + alias, e); |
| throw new ServiceSpecificException(ERROR_DECRYPTION_FAILED, |
| "Failed to recover key with alias '" + alias + "': " + e.getMessage()); |
| } catch (AEADBadTagException e) { |
| Log.e(TAG, "Got AEADBadTagException during decrypting application key with alias: " |
| + alias, e); |
| // Ignore the exception to continue to recover the other application keys. |
| } |
| } |
| if (!applicationKeys.isEmpty() && keyMaterialByAlias.isEmpty()) { |
| Log.e(TAG, "Failed to recover any of the application keys."); |
| throw new ServiceSpecificException(ERROR_DECRYPTION_FAILED, |
| "Failed to recover any of the application keys."); |
| } |
| return keyMaterialByAlias; |
| } |
| |
| /** |
| * This function can only be used inside LockSettingsService. |
| * |
| * @param storedHashType from {@code CredentialHash} |
| * @param credential - unencrypted byte array. Password length should be at most 16 symbols |
| * {@code mPasswordMaxLength} |
| * @param userId for user who just unlocked the device. |
| * @hide |
| */ |
| public void lockScreenSecretAvailable( |
| int storedHashType, @NonNull byte[] credential, int userId) { |
| // So as not to block the critical path unlocking the phone, defer to another thread. |
| try { |
| mExecutorService.execute(KeySyncTask.newInstance( |
| mContext, |
| mDatabase, |
| mSnapshotStorage, |
| mListenersStorage, |
| userId, |
| storedHashType, |
| credential, |
| /*credentialUpdated=*/ false)); |
| } catch (NoSuchAlgorithmException e) { |
| Log.wtf(TAG, "Should never happen - algorithm unavailable for KeySync", e); |
| } catch (KeyStoreException e) { |
| Log.e(TAG, "Key store error encountered during recoverable key sync", e); |
| } catch (InsecureUserException e) { |
| Log.wtf(TAG, "Impossible - insecure user, but user just entered lock screen", e); |
| } |
| } |
| |
| /** |
| * This function can only be used inside LockSettingsService. |
| * |
| * @param storedHashType from {@code CredentialHash} |
| * @param credential - unencrypted byte array |
| * @param userId for the user whose lock screen credentials were changed. |
| * @hide |
| */ |
| public void lockScreenSecretChanged( |
| int storedHashType, |
| @Nullable byte[] credential, |
| int userId) { |
| // So as not to block the critical path unlocking the phone, defer to another thread. |
| try { |
| mExecutorService.execute(KeySyncTask.newInstance( |
| mContext, |
| mDatabase, |
| mSnapshotStorage, |
| mListenersStorage, |
| userId, |
| storedHashType, |
| credential, |
| /*credentialUpdated=*/ true)); |
| } catch (NoSuchAlgorithmException e) { |
| Log.wtf(TAG, "Should never happen - algorithm unavailable for KeySync", e); |
| } catch (KeyStoreException e) { |
| Log.e(TAG, "Key store error encountered during recoverable key sync", e); |
| } catch (InsecureUserException e) { |
| Log.e(TAG, "InsecureUserException during lock screen secret update", e); |
| } |
| } |
| |
| private void checkRecoverKeyStorePermission() { |
| mContext.enforceCallingOrSelfPermission( |
| Manifest.permission.RECOVER_KEYSTORE, |
| "Caller " + Binder.getCallingUid() + " doesn't have RecoverKeyStore permission."); |
| int userId = UserHandle.getCallingUserId(); |
| int uid = Binder.getCallingUid(); |
| mCleanupManager.registerRecoveryAgent(userId, uid); |
| } |
| |
| private boolean publicKeysMatch(PublicKey publicKey, byte[] vaultParams) { |
| byte[] encodedPublicKey = SecureBox.encodePublicKey(publicKey); |
| return Arrays.equals(encodedPublicKey, Arrays.copyOf(vaultParams, encodedPublicKey.length)); |
| } |
| } |
