/*
* Copyright (C) 2012 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;
import android.content.BroadcastReceiver;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.pm.UserInfo;
import static android.Manifest.permission.ACCESS_KEYGUARD_SECURE_STORAGE;
import static android.content.Context.USER_SERVICE;
import static android.Manifest.permission.READ_PROFILE;
import android.database.sqlite.SQLiteDatabase;
import android.os.Binder;
import android.os.IBinder;
import android.os.Process;
import android.os.RemoteException;
import android.os.storage.IMountService;
import android.os.ServiceManager;
import android.os.SystemProperties;
import android.os.UserHandle;
import android.os.UserManager;
import android.provider.Settings;
import android.provider.Settings.Secure;
import android.provider.Settings.SettingNotFoundException;
import android.security.KeyStore;
import android.text.TextUtils;
import android.util.Slog;
import com.android.internal.widget.ILockSettings;
import com.android.internal.widget.LockPatternUtils;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Keeps the lock pattern/password data and related settings for each user.
* Used by LockPatternUtils. Needs to be a service because Settings app also needs
* to be able to save lockscreen information for secondary users.
* @hide
*/
public class LockSettingsService extends ILockSettings.Stub {
private static final String PERMISSION = ACCESS_KEYGUARD_SECURE_STORAGE;
private static final String TAG = "LockSettingsService";
private final Context mContext;
private final LockSettingsStorage mStorage;
private LockPatternUtils mLockPatternUtils;
private boolean mFirstCallToVold;
public LockSettingsService(Context context) {
mContext = context;
// Open the database
mLockPatternUtils = new LockPatternUtils(context);
mFirstCallToVold = true;
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_USER_ADDED);
filter.addAction(Intent.ACTION_USER_STARTING);
mContext.registerReceiverAsUser(mBroadcastReceiver, UserHandle.ALL, filter, null, null);
mStorage = new LockSettingsStorage(context, new LockSettingsStorage.Callback() {
@Override
public void initialize(SQLiteDatabase db) {
// Get the lockscreen default from a system property, if available
boolean lockScreenDisable = SystemProperties.getBoolean(
"ro.lockscreen.disable.default", false);
if (lockScreenDisable) {
mStorage.writeKeyValue(db, LockPatternUtils.DISABLE_LOCKSCREEN_KEY, "1", 0);
}
}
});
}
private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context context, Intent intent) {
if (Intent.ACTION_USER_ADDED.equals(intent.getAction())) {
final int userHandle = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0);
final int userSysUid = UserHandle.getUid(userHandle, Process.SYSTEM_UID);
final KeyStore ks = KeyStore.getInstance();
// Clear up keystore in case anything was left behind by previous users
ks.resetUid(userSysUid);
// If this user has a parent, sync with its keystore password
final UserManager um = (UserManager) mContext.getSystemService(USER_SERVICE);
final UserInfo parentInfo = um.getProfileParent(userHandle);
if (parentInfo != null) {
final int parentSysUid = UserHandle.getUid(parentInfo.id, Process.SYSTEM_UID);
ks.syncUid(parentSysUid, userSysUid);
}
} else if (Intent.ACTION_USER_STARTING.equals(intent.getAction())) {
final int userHandle = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0);
mStorage.prefetchUser(userHandle);
}
}
};
public void systemReady() {
migrateOldData();
mStorage.prefetchUser(UserHandle.USER_OWNER);
}
private void migrateOldData() {
try {
// These Settings moved before multi-user was enabled, so we only have to do it for the
// root user.
if (getString("migrated", null, 0) == null) {
final ContentResolver cr = mContext.getContentResolver();
for (String validSetting : VALID_SETTINGS) {
String value = Settings.Secure.getString(cr, validSetting);
if (value != null) {
setString(validSetting, value, 0);
}
}
// No need to move the password / pattern files. They're already in the right place.
setString("migrated", "true", 0);
Slog.i(TAG, "Migrated lock settings to new location");
}
// These Settings changed after multi-user was enabled, hence need to be moved per user.
if (getString("migrated_user_specific", null, 0) == null) {
final UserManager um = (UserManager) mContext.getSystemService(USER_SERVICE);
final ContentResolver cr = mContext.getContentResolver();
List<UserInfo> users = um.getUsers();
for (int user = 0; user < users.size(); user++) {
// Migrate owner info
final int userId = users.get(user).id;
final String OWNER_INFO = Secure.LOCK_SCREEN_OWNER_INFO;
String ownerInfo = Settings.Secure.getStringForUser(cr, OWNER_INFO, userId);
if (ownerInfo != null) {
setString(OWNER_INFO, ownerInfo, userId);
Settings.Secure.putStringForUser(cr, ownerInfo, "", userId);
}
// Migrate owner info enabled. Note there was a bug where older platforms only
// stored this value if the checkbox was toggled at least once. The code detects
// this case by handling the exception.
final String OWNER_INFO_ENABLED = Secure.LOCK_SCREEN_OWNER_INFO_ENABLED;
boolean enabled;
try {
int ivalue = Settings.Secure.getIntForUser(cr, OWNER_INFO_ENABLED, userId);
enabled = ivalue != 0;
setLong(OWNER_INFO_ENABLED, enabled ? 1 : 0, userId);
} catch (SettingNotFoundException e) {
// Setting was never stored. Store it if the string is not empty.
if (!TextUtils.isEmpty(ownerInfo)) {
setLong(OWNER_INFO_ENABLED, 1, userId);
}
}
Settings.Secure.putIntForUser(cr, OWNER_INFO_ENABLED, 0, userId);
}
// No need to move the password / pattern files. They're already in the right place.
setString("migrated_user_specific", "true", 0);
Slog.i(TAG, "Migrated per-user lock settings to new location");
}
} catch (RemoteException re) {
Slog.e(TAG, "Unable to migrate old data", re);
}
}
private final void checkWritePermission(int userId) {
mContext.enforceCallingOrSelfPermission(PERMISSION, "LockSettingsWrite");
}
private final void checkPasswordReadPermission(int userId) {
mContext.enforceCallingOrSelfPermission(PERMISSION, "LockSettingsRead");
}
private final void checkReadPermission(String requestedKey, int userId) {
final int callingUid = Binder.getCallingUid();
for (int i = 0; i < READ_PROFILE_PROTECTED_SETTINGS.length; i++) {
String key = READ_PROFILE_PROTECTED_SETTINGS[i];
if (key.equals(requestedKey) && mContext.checkCallingOrSelfPermission(READ_PROFILE)
!= PackageManager.PERMISSION_GRANTED) {
throw new SecurityException("uid=" + callingUid
+ " needs permission " + READ_PROFILE + " to read "
+ requestedKey + " for user " + userId);
}
}
}
@Override
public void setBoolean(String key, boolean value, int userId) throws RemoteException {
checkWritePermission(userId);
setStringUnchecked(key, userId, value ? "1" : "0");
}
@Override
public void setLong(String key, long value, int userId) throws RemoteException {
checkWritePermission(userId);
setStringUnchecked(key, userId, Long.toString(value));
}
@Override
public void setString(String key, String value, int userId) throws RemoteException {
checkWritePermission(userId);
setStringUnchecked(key, userId, value);
}
private void setStringUnchecked(String key, int userId, String value) {
mStorage.writeKeyValue(key, value, userId);
}
@Override
public boolean getBoolean(String key, boolean defaultValue, int userId) throws RemoteException {
checkReadPermission(key, userId);
String value = mStorage.readKeyValue(key, null, userId);
return TextUtils.isEmpty(value) ?
defaultValue : (value.equals("1") || value.equals("true"));
}
@Override
public long getLong(String key, long defaultValue, int userId) throws RemoteException {
checkReadPermission(key, userId);
String value = mStorage.readKeyValue(key, null, userId);
return TextUtils.isEmpty(value) ? defaultValue : Long.parseLong(value);
}
@Override
public String getString(String key, String defaultValue, int userId) throws RemoteException {
checkReadPermission(key, userId);
return mStorage.readKeyValue(key, defaultValue, userId);
}
@Override
public boolean havePassword(int userId) throws RemoteException {
// Do we need a permissions check here?
return mStorage.hasPassword(userId);
}
@Override
public boolean havePattern(int userId) throws RemoteException {
// Do we need a permissions check here?
return mStorage.hasPattern(userId);
}
private void maybeUpdateKeystore(String password, int userHandle) {
final UserManager um = (UserManager) mContext.getSystemService(USER_SERVICE);
final KeyStore ks = KeyStore.getInstance();
final List<UserInfo> profiles = um.getProfiles(userHandle);
boolean shouldReset = TextUtils.isEmpty(password);
// For historical reasons, don't wipe a non-empty keystore if we have a single user with a
// single profile.
if (userHandle == UserHandle.USER_OWNER && profiles.size() == 1) {
if (!ks.isEmpty()) {
shouldReset = false;
}
}
for (UserInfo pi : profiles) {
final int profileUid = UserHandle.getUid(pi.id, Process.SYSTEM_UID);
if (shouldReset) {
ks.resetUid(profileUid);
} else {
ks.passwordUid(password, profileUid);
}
}
}
@Override
public void setLockPattern(String pattern, int userId) throws RemoteException {
checkWritePermission(userId);
maybeUpdateKeystore(pattern, userId);
final byte[] hash = LockPatternUtils.patternToHash(
LockPatternUtils.stringToPattern(pattern));
mStorage.writePatternHash(hash, userId);
}
@Override
public void setLockPassword(String password, int userId) throws RemoteException {
checkWritePermission(userId);
maybeUpdateKeystore(password, userId);
mStorage.writePasswordHash(mLockPatternUtils.passwordToHash(password, userId), userId);
}
@Override
public boolean checkPattern(String pattern, int userId) throws RemoteException {
checkPasswordReadPermission(userId);
byte[] hash = LockPatternUtils.patternToHash(LockPatternUtils.stringToPattern(pattern));
byte[] storedHash = mStorage.readPatternHash(userId);
if (storedHash == null) {
return true;
}
boolean matched = Arrays.equals(hash, storedHash);
if (matched && !TextUtils.isEmpty(pattern)) {
maybeUpdateKeystore(pattern, userId);
}
return matched;
}
@Override
public boolean checkPassword(String password, int userId) throws RemoteException {
checkPasswordReadPermission(userId);
byte[] hash = mLockPatternUtils.passwordToHash(password, userId);
byte[] storedHash = mStorage.readPasswordHash(userId);
if (storedHash == null) {
return true;
}
boolean matched = Arrays.equals(hash, storedHash);
if (matched && !TextUtils.isEmpty(password)) {
maybeUpdateKeystore(password, userId);
}
return matched;
}
@Override
public boolean checkVoldPassword(int userId) throws RemoteException {
if (!mFirstCallToVold) {
return false;
}
mFirstCallToVold = false;
checkPasswordReadPermission(userId);
// There's no guarantee that this will safely connect, but if it fails
// we will simply show the lock screen when we shouldn't, so relatively
// benign. There is an outside chance something nasty would happen if
// this service restarted before vold stales out the password in this
// case. The nastiness is limited to not showing the lock screen when
// we should, within the first minute of decrypting the phone if this
// service can't connect to vold, it restarts, and then the new instance
// does successfully connect.
final IMountService service = getMountService();
String password = service.getPassword();
service.clearPassword();
if (password == null) {
return false;
}
try {
if (mLockPatternUtils.isLockPatternEnabled()) {
if (checkPattern(password, userId)) {
return true;
}
}
} catch (Exception e) {
}
try {
if (mLockPatternUtils.isLockPasswordEnabled()) {
if (checkPassword(password, userId)) {
return true;
}
}
} catch (Exception e) {
}
return false;
}
@Override
public void removeUser(int userId) {
checkWritePermission(userId);
mStorage.removeUser(userId);
final KeyStore ks = KeyStore.getInstance();
final int userUid = UserHandle.getUid(userId, Process.SYSTEM_UID);
ks.resetUid(userUid);
}
private static final String[] VALID_SETTINGS = new String[] {
LockPatternUtils.LOCKOUT_PERMANENT_KEY,
LockPatternUtils.LOCKOUT_ATTEMPT_DEADLINE,
LockPatternUtils.PATTERN_EVER_CHOSEN_KEY,
LockPatternUtils.PASSWORD_TYPE_KEY,
LockPatternUtils.PASSWORD_TYPE_ALTERNATE_KEY,
LockPatternUtils.LOCK_PASSWORD_SALT_KEY,
LockPatternUtils.DISABLE_LOCKSCREEN_KEY,
LockPatternUtils.LOCKSCREEN_OPTIONS,
LockPatternUtils.LOCKSCREEN_BIOMETRIC_WEAK_FALLBACK,
LockPatternUtils.BIOMETRIC_WEAK_EVER_CHOSEN_KEY,
LockPatternUtils.LOCKSCREEN_POWER_BUTTON_INSTANTLY_LOCKS,
LockPatternUtils.PASSWORD_HISTORY_KEY,
Secure.LOCK_PATTERN_ENABLED,
Secure.LOCK_BIOMETRIC_WEAK_FLAGS,
Secure.LOCK_PATTERN_VISIBLE,
Secure.LOCK_PATTERN_TACTILE_FEEDBACK_ENABLED
};
// These are protected with a read permission
private static final String[] READ_PROFILE_PROTECTED_SETTINGS = new String[] {
Secure.LOCK_SCREEN_OWNER_INFO_ENABLED,
Secure.LOCK_SCREEN_OWNER_INFO
};
private IMountService getMountService() {
final IBinder service = ServiceManager.getService("mount");
if (service != null) {
return IMountService.Stub.asInterface(service);
}
return null;
}
}
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