/*
|
* 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);
|
}
|
}
|
}
|
|
}
|
