| /* |
| * Copyright (C) 2018 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.biometrics; |
| |
| import android.content.Context; |
| import android.hardware.biometrics.BiometricAuthenticator; |
| import android.os.AsyncTask; |
| import android.os.Environment; |
| import android.util.Slog; |
| import android.util.Xml; |
| |
| import com.android.internal.annotations.GuardedBy; |
| |
| import libcore.io.IoUtils; |
| |
| import org.xmlpull.v1.XmlPullParser; |
| import org.xmlpull.v1.XmlPullParserException; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Abstract base class for managing biometrics per user across device reboots. |
| * @hide |
| */ |
| public abstract class BiometricUserState<T extends BiometricAuthenticator.Identifier> { |
| private static final String TAG = "UserState"; |
| |
| @GuardedBy("this") |
| protected final ArrayList<T> mBiometrics = new ArrayList<>(); |
| protected final Context mContext; |
| protected final File mFile; |
| |
| private final Runnable mWriteStateRunnable = new Runnable() { |
| @Override |
| public void run() { |
| doWriteState(); |
| } |
| }; |
| |
| /** |
| * @return The tag for the biometrics. There may be multiple instances of a biometric within. |
| */ |
| protected abstract String getBiometricsTag(); |
| |
| /** |
| * @return The file where the biometric metadata should be stored. |
| */ |
| protected abstract String getBiometricFile(); |
| |
| /** |
| * @return The resource for the name template, this is used to generate the default name. |
| */ |
| protected abstract int getNameTemplateResource(); |
| |
| /** |
| * @return A copy of the list. |
| */ |
| protected abstract ArrayList<T> getCopy(ArrayList<T> array); |
| |
| /** |
| * @return Writes the cached data to persistent storage. |
| */ |
| protected abstract void doWriteState(); |
| |
| /** |
| * @return |
| */ |
| protected abstract void parseBiometricsLocked(XmlPullParser parser) |
| throws IOException, XmlPullParserException; |
| |
| |
| public BiometricUserState(Context context, int userId) { |
| mFile = getFileForUser(userId); |
| mContext = context; |
| synchronized (this) { |
| readStateSyncLocked(); |
| } |
| } |
| |
| public void addBiometric(T identifier) { |
| synchronized (this) { |
| mBiometrics.add(identifier); |
| scheduleWriteStateLocked(); |
| } |
| } |
| |
| public void removeBiometric(int biometricId) { |
| synchronized (this) { |
| for (int i = 0; i < mBiometrics.size(); i++) { |
| if (mBiometrics.get(i).getBiometricId() == biometricId) { |
| mBiometrics.remove(i); |
| scheduleWriteStateLocked(); |
| break; |
| } |
| } |
| } |
| } |
| |
| public void renameBiometric(int biometricId, CharSequence name) { |
| synchronized (this) { |
| for (int i = 0; i < mBiometrics.size(); i++) { |
| if (mBiometrics.get(i).getBiometricId() == biometricId) { |
| BiometricAuthenticator.Identifier identifier = mBiometrics.get(i); |
| identifier.setName(name); |
| scheduleWriteStateLocked(); |
| break; |
| } |
| } |
| } |
| } |
| |
| public List<T> getBiometrics() { |
| synchronized (this) { |
| return getCopy(mBiometrics); |
| } |
| } |
| |
| /** |
| * Finds a unique name for the given fingerprint |
| * @return unique name |
| */ |
| public String getUniqueName() { |
| int guess = 1; |
| while (true) { |
| // Not the most efficient algorithm in the world, but there shouldn't be more than 10 |
| String name = mContext.getString(getNameTemplateResource(), guess); |
| if (isUnique(name)) { |
| return name; |
| } |
| guess++; |
| } |
| } |
| |
| private boolean isUnique(String name) { |
| for (T identifier : mBiometrics) { |
| if (identifier.getName().equals(name)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| private File getFileForUser(int userId) { |
| return new File(Environment.getUserSystemDirectory(userId), getBiometricFile()); |
| } |
| |
| private void scheduleWriteStateLocked() { |
| AsyncTask.execute(mWriteStateRunnable); |
| } |
| |
| @GuardedBy("this") |
| private void readStateSyncLocked() { |
| FileInputStream in; |
| if (!mFile.exists()) { |
| return; |
| } |
| try { |
| in = new FileInputStream(mFile); |
| } catch (FileNotFoundException fnfe) { |
| Slog.i(TAG, "No fingerprint state"); |
| return; |
| } |
| try { |
| XmlPullParser parser = Xml.newPullParser(); |
| parser.setInput(in, null); |
| parseStateLocked(parser); |
| |
| } catch (XmlPullParserException | IOException e) { |
| throw new IllegalStateException("Failed parsing settings file: " |
| + mFile , e); |
| } finally { |
| IoUtils.closeQuietly(in); |
| } |
| } |
| |
| @GuardedBy("this") |
| private void parseStateLocked(XmlPullParser parser) |
| throws IOException, XmlPullParserException { |
| final int outerDepth = parser.getDepth(); |
| int type; |
| while ((type = parser.next()) != XmlPullParser.END_DOCUMENT |
| && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) { |
| if (type == XmlPullParser.END_TAG || type == XmlPullParser.TEXT) { |
| continue; |
| } |
| |
| String tagName = parser.getName(); |
| if (tagName.equals(getBiometricsTag())) { |
| parseBiometricsLocked(parser); |
| } |
| } |
| } |
| |
| } |