/* * Copyright (C) 2013-2014 Dominik Schürmann * Copyright (C) 2015 Kent Nguyen * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ package org.sufficientlysecure.keychain.util; import android.annotation.TargetApi; import android.app.Activity; import android.content.Intent; import android.content.pm.PackageManager; import android.net.Uri; import android.nfc.NdefMessage; import android.nfc.NdefRecord; import android.nfc.NfcAdapter; import android.nfc.NfcEvent; import android.os.AsyncTask; import android.os.Build; import android.os.Handler; import android.os.Message; import android.provider.Settings; import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.R; import org.sufficientlysecure.keychain.provider.KeychainContract; import org.sufficientlysecure.keychain.provider.ProviderHelper; import org.sufficientlysecure.keychain.ui.util.Notify; import java.lang.ref.WeakReference; /** * This class contains NFC functionality that can be shared across Fragments or Activities. */ public class NfcHelper { private Activity mActivity; private ProviderHelper mProviderHelper; /** * NFC: This handler receives a message from onNdefPushComplete */ private static NfcHandler mNfcHandler; private NfcAdapter mNfcAdapter; private NfcAdapter.CreateNdefMessageCallback mNdefCallback; private NfcAdapter.OnNdefPushCompleteCallback mNdefCompleteCallback; private byte[] mNfcKeyringBytes; private static final int NFC_SENT = 1; /** * Initializes the NfcHelper. */ public NfcHelper(final Activity activity, final ProviderHelper providerHelper) { mActivity = activity; mProviderHelper = providerHelper; mNfcHandler = new NfcHandler(mActivity); } /** * Return true if the NFC Adapter of this Helper has any features enabled. * * @return true if this NFC Adapter has any features enabled */ public boolean isEnabled() { return mNfcAdapter.isEnabled(); } /** * NFC: Initialize NFC sharing if OS and device supports it */ @TargetApi(Build.VERSION_CODES.JELLY_BEAN) public void initNfc(final Uri dataUri) { // check if NFC Beam is supported (>= Android 4.1) if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) { // Implementation for the CreateNdefMessageCallback interface mNdefCallback = new NfcAdapter.CreateNdefMessageCallback() { @Override public NdefMessage createNdefMessage(NfcEvent event) { /* * When a device receives a push with an AAR in it, the application specified in the AAR is * guaranteed to run. The AAR overrides the tag dispatch system. You can add it back in to * guarantee that this activity starts when receiving a beamed message. For now, this code * uses the tag dispatch system. */ return new NdefMessage(NdefRecord.createMime(Constants.MIME_TYPE_KEYS, mNfcKeyringBytes), NdefRecord.createApplicationRecord(Constants.PACKAGE_NAME)); } }; // Implementation for the OnNdefPushCompleteCallback interface mNdefCompleteCallback = new NfcAdapter.OnNdefPushCompleteCallback() { @Override public void onNdefPushComplete(NfcEvent event) { // A handler is needed to send messages to the activity when this // callback occurs, because it happens from a binder thread mNfcHandler.obtainMessage(NFC_SENT).sendToTarget(); } }; // Check for available NFC Adapter mNfcAdapter = NfcAdapter.getDefaultAdapter(mActivity); if (mNfcAdapter != null) { /* * Retrieve mNfcKeyringBytes here asynchronously (to not block the UI) * and init nfc adapter afterwards. * mNfcKeyringBytes can not be retrieved in createNdefMessage, because this process * has no permissions to query the Uri. */ AsyncTask initTask = new AsyncTask() { protected Void doInBackground(Void... unused) { try { Uri blobUri = KeychainContract.KeyRingData.buildPublicKeyRingUri(dataUri); mNfcKeyringBytes = (byte[]) mProviderHelper.getGenericData( blobUri, KeychainContract.KeyRingData.KEY_RING_DATA, ProviderHelper.FIELD_TYPE_BLOB); } catch (ProviderHelper.NotFoundException e) { Log.e(Constants.TAG, "key not found!", e); } // no AsyncTask return (Void) return null; } protected void onPostExecute(Void unused) { if (mActivity.isFinishing()) { return; } // Register callback to set NDEF message mNfcAdapter.setNdefPushMessageCallback(mNdefCallback, mActivity); // Register callback to listen for message-sent success mNfcAdapter.setOnNdefPushCompleteCallback(mNdefCompleteCallback, mActivity); } }; initTask.execute(); } } } @TargetApi(Build.VERSION_CODES.LOLLIPOP) public void invokeNfcBeam() { // Check if device supports NFC if (!mActivity.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)) { Notify.create(mActivity, R.string.no_nfc_support, Notify.LENGTH_LONG, Notify.Style.ERROR).show(); return; } // Check for available NFC Adapter mNfcAdapter = NfcAdapter.getDefaultAdapter(mActivity); if (mNfcAdapter == null || !mNfcAdapter.isEnabled()) { Notify.create(mActivity, R.string.error_nfc_needed, Notify.LENGTH_LONG, Notify.Style.ERROR, new Notify.ActionListener() { @Override public void onAction() { Intent intentSettings = new Intent(Settings.ACTION_NFC_SETTINGS); mActivity.startActivity(intentSettings); } }, R.string.menu_nfc_preferences).show(); return; } if (!mNfcAdapter.isNdefPushEnabled()) { Notify.create(mActivity, R.string.error_beam_needed, Notify.LENGTH_LONG, Notify.Style.ERROR, new Notify.ActionListener() { @Override public void onAction() { Intent intentSettings = new Intent(Settings.ACTION_NFCSHARING_SETTINGS); mActivity.startActivity(intentSettings); } }, R.string.menu_beam_preferences).show(); return; } mNfcAdapter.invokeBeam(mActivity); } private static class NfcHandler extends Handler { private final WeakReference mActivityReference; public NfcHandler(Activity activity) { mActivityReference = new WeakReference<>(activity); } @Override public void handleMessage(Message msg) { if (mActivityReference.get() != null) { switch (msg.what) { case NFC_SENT: Notify.create(mActivityReference.get(), R.string.nfc_successful, Notify.Style.OK).show(); break; } } } } }