/*
* Copyright (C) 2009 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 android.security;
import android.app.ActivityThread;
import android.app.Application;
import android.app.KeyguardManager;
import android.content.Context;
import android.hardware.fingerprint.FingerprintManager;
import android.os.Binder;
import android.os.IBinder;
import android.os.Process;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.UserHandle;
import android.security.keymaster.ExportResult;
import android.security.keymaster.KeyCharacteristics;
import android.security.keymaster.KeymasterArguments;
import android.security.keymaster.KeymasterBlob;
import android.security.keymaster.KeymasterDefs;
import android.security.keymaster.OperationResult;
import android.security.keystore.KeyExpiredException;
import android.security.keystore.KeyNotYetValidException;
import android.security.keystore.KeyPermanentlyInvalidatedException;
import android.security.keystore.UserNotAuthenticatedException;
import android.util.Log;
import java.math.BigInteger;
import java.security.InvalidKeyException;
import java.util.List;
import java.util.Locale;
/**
* @hide This should not be made public in its present form because it
* assumes that private and secret key bytes are available and would
* preclude the use of hardware crypto.
*/
public class KeyStore {
private static final String TAG = "KeyStore";
// ResponseCodes
public static final int NO_ERROR = 1;
public static final int LOCKED = 2;
public static final int UNINITIALIZED = 3;
public static final int SYSTEM_ERROR = 4;
public static final int PROTOCOL_ERROR = 5;
public static final int PERMISSION_DENIED = 6;
public static final int KEY_NOT_FOUND = 7;
public static final int VALUE_CORRUPTED = 8;
public static final int UNDEFINED_ACTION = 9;
public static final int WRONG_PASSWORD = 10;
/**
* Per operation authentication is needed before this operation is valid.
* This is returned from {@link #begin} when begin succeeds but the operation uses
* per-operation authentication and must authenticate before calling {@link #update} or
* {@link #finish}.
*/
public static final int OP_AUTH_NEEDED = 15;
// Used for UID field to indicate the calling UID.
public static final int UID_SELF = -1;
// Flags for "put" "import" and "generate"
public static final int FLAG_NONE = 0;
/**
* Indicates that this key (or key pair) must be encrypted at rest. This will protect the key
* (or key pair) with the secure lock screen credential (e.g., password, PIN, or pattern).
*
* <p>Note that this requires that the secure lock screen (e.g., password, PIN, pattern) is set
* up, otherwise key (or key pair) generation or import will fail. Moreover, this key (or key
* pair) will be deleted when the secure lock screen is disabled or reset (e.g., by the user or
* a Device Administrator). Finally, this key (or key pair) cannot be used until the user
* unlocks the secure lock screen after boot.
*
* @see KeyguardManager#isDeviceSecure()
*/
public static final int FLAG_ENCRYPTED = 1;
// States
public enum State { UNLOCKED, LOCKED, UNINITIALIZED };
private int mError = NO_ERROR;
private final IKeystoreService mBinder;
private final Context mContext;
private IBinder mToken;
private KeyStore(IKeystoreService binder) {
mBinder = binder;
mContext = getApplicationContext();
}
public static Context getApplicationContext() {
Application application = ActivityThread.currentApplication();
if (application == null) {
throw new IllegalStateException(
"Failed to obtain application Context from ActivityThread");
}
return application;
}
public static KeyStore getInstance() {
IKeystoreService keystore = IKeystoreService.Stub.asInterface(ServiceManager
.getService("android.security.keystore"));
return new KeyStore(keystore);
}
private synchronized IBinder getToken() {
if (mToken == null) {
mToken = new Binder();
}
return mToken;
}
public State state(int userId) {
final int ret;
try {
ret = mBinder.getState(userId);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
throw new AssertionError(e);
}
switch (ret) {
case NO_ERROR: return State.UNLOCKED;
case LOCKED: return State.LOCKED;
case UNINITIALIZED: return State.UNINITIALIZED;
default: throw new AssertionError(mError);
}
}
public State state() {
return state(UserHandle.myUserId());
}
public boolean isUnlocked() {
return state() == State.UNLOCKED;
}
public byte[] get(String key) {
try {
return mBinder.get(key);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public boolean put(String key, byte[] value, int uid, int flags) {
return insert(key, value, uid, flags) == NO_ERROR;
}
public int insert(String key, byte[] value, int uid, int flags) {
try {
return mBinder.insert(key, value, uid, flags);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return SYSTEM_ERROR;
}
}
public boolean delete(String key, int uid) {
try {
return mBinder.del(key, uid) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean delete(String key) {
return delete(key, UID_SELF);
}
public boolean contains(String key, int uid) {
try {
return mBinder.exist(key, uid) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean contains(String key) {
return contains(key, UID_SELF);
}
/**
* List all entries in the keystore for {@code uid} starting with {@code prefix}.
*/
public String[] list(String prefix, int uid) {
try {
return mBinder.list(prefix, uid);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public String[] list(String prefix) {
return list(prefix, UID_SELF);
}
public boolean reset() {
try {
return mBinder.reset() == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
/**
* Attempt to lock the keystore for {@code user}.
*
* @param user Android user to lock.
* @return whether {@code user}'s keystore was locked.
*/
public boolean lock(int userId) {
try {
return mBinder.lock(userId) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean lock() {
return lock(UserHandle.myUserId());
}
/**
* Attempt to unlock the keystore for {@code user} with the password {@code password}.
* This is required before keystore entries created with FLAG_ENCRYPTED can be accessed or
* created.
*
* @param user Android user ID to operate on
* @param password user's keystore password. Should be the most recent value passed to
* {@link #onUserPasswordChanged} for the user.
*
* @return whether the keystore was unlocked.
*/
public boolean unlock(int userId, String password) {
try {
mError = mBinder.unlock(userId, password);
return mError == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean unlock(String password) {
return unlock(UserHandle.getUserId(Process.myUid()), password);
}
/**
* Check if the keystore for {@code userId} is empty.
*/
public boolean isEmpty(int userId) {
try {
return mBinder.isEmpty(userId) != 0;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean isEmpty() {
return isEmpty(UserHandle.myUserId());
}
public boolean generate(String key, int uid, int keyType, int keySize, int flags,
byte[][] args) {
try {
return mBinder.generate(key, uid, keyType, keySize, flags,
new KeystoreArguments(args)) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean importKey(String keyName, byte[] key, int uid, int flags) {
try {
return mBinder.import_key(keyName, key, uid, flags) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public byte[] sign(String key, byte[] data) {
try {
return mBinder.sign(key, data);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public boolean verify(String key, byte[] data, byte[] signature) {
try {
return mBinder.verify(key, data, signature) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean grant(String key, int uid) {
try {
return mBinder.grant(key, uid) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean ungrant(String key, int uid) {
try {
return mBinder.ungrant(key, uid) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
/**
* Returns the last modification time of the key in milliseconds since the
* epoch. Will return -1L if the key could not be found or other error.
*/
public long getmtime(String key) {
try {
final long millis = mBinder.getmtime(key);
if (millis == -1L) {
return -1L;
}
return millis * 1000L;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return -1L;
}
}
public boolean duplicate(String srcKey, int srcUid, String destKey, int destUid) {
try {
return mBinder.duplicate(srcKey, srcUid, destKey, destUid) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
// TODO: remove this when it's removed from Settings
public boolean isHardwareBacked() {
return isHardwareBacked("RSA");
}
public boolean isHardwareBacked(String keyType) {
try {
return mBinder.is_hardware_backed(keyType.toUpperCase(Locale.US)) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public boolean clearUid(int uid) {
try {
return mBinder.clear_uid(uid) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public int getLastError() {
return mError;
}
public boolean addRngEntropy(byte[] data) {
try {
return mBinder.addRngEntropy(data) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
public int generateKey(String alias, KeymasterArguments args, byte[] entropy, int uid,
int flags, KeyCharacteristics outCharacteristics) {
try {
return mBinder.generateKey(alias, args, entropy, uid, flags, outCharacteristics);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return SYSTEM_ERROR;
}
}
public int generateKey(String alias, KeymasterArguments args, byte[] entropy, int flags,
KeyCharacteristics outCharacteristics) {
return generateKey(alias, args, entropy, UID_SELF, flags, outCharacteristics);
}
public int getKeyCharacteristics(String alias, KeymasterBlob clientId, KeymasterBlob appId,
KeyCharacteristics outCharacteristics) {
try {
return mBinder.getKeyCharacteristics(alias, clientId, appId, outCharacteristics);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return SYSTEM_ERROR;
}
}
public int importKey(String alias, KeymasterArguments args, int format, byte[] keyData,
int uid, int flags, KeyCharacteristics outCharacteristics) {
try {
return mBinder.importKey(alias, args, format, keyData, uid, flags,
outCharacteristics);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return SYSTEM_ERROR;
}
}
public int importKey(String alias, KeymasterArguments args, int format, byte[] keyData,
int flags, KeyCharacteristics outCharacteristics) {
return importKey(alias, args, format, keyData, UID_SELF, flags, outCharacteristics);
}
public ExportResult exportKey(String alias, int format, KeymasterBlob clientId,
KeymasterBlob appId) {
try {
return mBinder.exportKey(alias, format, clientId, appId);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public OperationResult begin(String alias, int purpose, boolean pruneable,
KeymasterArguments args, byte[] entropy) {
try {
return mBinder.begin(getToken(), alias, purpose, pruneable, args, entropy);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public OperationResult update(IBinder token, KeymasterArguments arguments, byte[] input) {
try {
return mBinder.update(token, arguments, input);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public OperationResult finish(IBinder token, KeymasterArguments arguments, byte[] signature,
byte[] entropy) {
try {
return mBinder.finish(token, arguments, signature, entropy);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return null;
}
}
public OperationResult finish(IBinder token, KeymasterArguments arguments, byte[] signature) {
return finish(token, arguments, signature, null);
}
public int abort(IBinder token) {
try {
return mBinder.abort(token);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return SYSTEM_ERROR;
}
}
/**
* Check if the operation referenced by {@code token} is currently authorized.
*
* @param token An operation token returned by a call to
* {@link #begin(String, int, boolean, KeymasterArguments, byte[], KeymasterArguments) begin}.
*/
public boolean isOperationAuthorized(IBinder token) {
try {
return mBinder.isOperationAuthorized(token);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
/**
* Add an authentication record to the keystore authorization table.
*
* @param authToken The packed bytes of a hw_auth_token_t to be provided to keymaster.
* @return {@code KeyStore.NO_ERROR} on success, otherwise an error value corresponding to
* a {@code KeymasterDefs.KM_ERROR_} value or {@code KeyStore} ResponseCode.
*/
public int addAuthToken(byte[] authToken) {
try {
return mBinder.addAuthToken(authToken);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return SYSTEM_ERROR;
}
}
/**
* Notify keystore that a user's password has changed.
*
* @param userId the user whose password changed.
* @param newPassword the new password or "" if the password was removed.
*/
public boolean onUserPasswordChanged(int userId, String newPassword) {
// Parcel.cpp doesn't support deserializing null strings and treats them as "". Make that
// explicit here.
if (newPassword == null) {
newPassword = "";
}
try {
return mBinder.onUserPasswordChanged(userId, newPassword) == NO_ERROR;
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
return false;
}
}
/**
* Notify keystore that a user was added.
*
* @param userId the new user.
* @param parentId the parent of the new user, or -1 if the user has no parent. If parentId is
* specified then the new user's keystore will be intialized with the same secure lockscreen
* password as the parent.
*/
public void onUserAdded(int userId, int parentId) {
try {
mBinder.onUserAdded(userId, parentId);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
}
}
/**
* Notify keystore that a user was added.
*
* @param userId the new user.
*/
public void onUserAdded(int userId) {
onUserAdded(userId, -1);
}
/**
* Notify keystore that a user was removed.
*
* @param userId the removed user.
*/
public void onUserRemoved(int userId) {
try {
mBinder.onUserRemoved(userId);
} catch (RemoteException e) {
Log.w(TAG, "Cannot connect to keystore", e);
}
}
public boolean onUserPasswordChanged(String newPassword) {
return onUserPasswordChanged(UserHandle.getUserId(Process.myUid()), newPassword);
}
/**
* Returns a {@link KeyStoreException} corresponding to the provided keystore/keymaster error
* code.
*/
public static KeyStoreException getKeyStoreException(int errorCode) {
if (errorCode > 0) {
// KeyStore layer error
switch (errorCode) {
case NO_ERROR:
return new KeyStoreException(errorCode, "OK");
case LOCKED:
return new KeyStoreException(errorCode, "User authentication required");
case UNINITIALIZED:
return new KeyStoreException(errorCode, "Keystore not initialized");
case SYSTEM_ERROR:
return new KeyStoreException(errorCode, "System error");
case PERMISSION_DENIED:
return new KeyStoreException(errorCode, "Permission denied");
case KEY_NOT_FOUND:
return new KeyStoreException(errorCode, "Key not found");
case VALUE_CORRUPTED:
return new KeyStoreException(errorCode, "Key blob corrupted");
case OP_AUTH_NEEDED:
return new KeyStoreException(errorCode, "Operation requires authorization");
default:
return new KeyStoreException(errorCode, String.valueOf(errorCode));
}
} else {
// Keymaster layer error
switch (errorCode) {
case KeymasterDefs.KM_ERROR_INVALID_AUTHORIZATION_TIMEOUT:
// The name of this parameter significantly differs between Keymaster and
// framework APIs. Use the framework wording to make life easier for developers.
return new KeyStoreException(errorCode,
"Invalid user authentication validity duration");
default:
return new KeyStoreException(errorCode,
KeymasterDefs.getErrorMessage(errorCode));
}
}
}
/**
* Returns an {@link InvalidKeyException} corresponding to the provided
* {@link KeyStoreException}.
*/
public InvalidKeyException getInvalidKeyException(
String keystoreKeyAlias, KeyStoreException e) {
switch (e.getErrorCode()) {
case LOCKED:
return new UserNotAuthenticatedException();
case KeymasterDefs.KM_ERROR_KEY_EXPIRED:
return new KeyExpiredException();
case KeymasterDefs.KM_ERROR_KEY_NOT_YET_VALID:
return new KeyNotYetValidException();
case KeymasterDefs.KM_ERROR_KEY_USER_NOT_AUTHENTICATED:
case OP_AUTH_NEEDED:
{
// We now need to determine whether the key/operation can become usable if user
// authentication is performed, or whether it can never become usable again.
// User authentication requirements are contained in the key's characteristics. We
// need to check whether these requirements can be be satisfied by asking the user
// to authenticate.
KeyCharacteristics keyCharacteristics = new KeyCharacteristics();
int getKeyCharacteristicsErrorCode =
getKeyCharacteristics(keystoreKeyAlias, null, null, keyCharacteristics);
if (getKeyCharacteristicsErrorCode != NO_ERROR) {
return new InvalidKeyException(
"Failed to obtained key characteristics",
getKeyStoreException(getKeyCharacteristicsErrorCode));
}
List<BigInteger> keySids =
keyCharacteristics.getUnsignedLongs(KeymasterDefs.KM_TAG_USER_SECURE_ID);
if (keySids.isEmpty()) {
// Key is not bound to any SIDs -- no amount of authentication will help here.
return new KeyPermanentlyInvalidatedException();
}
long rootSid = GateKeeper.getSecureUserId();
if ((rootSid != 0) && (keySids.contains(KeymasterArguments.toUint64(rootSid)))) {
// One of the key's SIDs is the current root SID -- user can be authenticated
// against that SID.
return new UserNotAuthenticatedException();
}
long fingerprintOnlySid = getFingerprintOnlySid();
if ((fingerprintOnlySid != 0)
&& (keySids.contains(KeymasterArguments.toUint64(fingerprintOnlySid)))) {
// One of the key's SIDs is the current fingerprint SID -- user can be
// authenticated against that SID.
return new UserNotAuthenticatedException();
}
// None of the key's SIDs can ever be authenticated
return new KeyPermanentlyInvalidatedException();
}
default:
return new InvalidKeyException("Keystore operation failed", e);
}
}
private long getFingerprintOnlySid() {
FingerprintManager fingerprintManager = mContext.getSystemService(FingerprintManager.class);
if (fingerprintManager == null) {
return 0;
}
// TODO: Restore USE_FINGERPRINT permission check in
// FingerprintManager.getAuthenticatorId once the ID is no longer needed here.
return fingerprintManager.getAuthenticatorId();
}
/**
* Returns an {@link InvalidKeyException} corresponding to the provided keystore/keymaster error
* code.
*/
public InvalidKeyException getInvalidKeyException(String keystoreKeyAlias, int errorCode) {
return getInvalidKeyException(keystoreKeyAlias, getKeyStoreException(errorCode));
}
}