Java tutorial
/* * Copyright (C) 2015 Dominik Schrmann <dominik@dominikschuermann.de> * Copyright (C) 2015 Vincent Breitmoser <v.breitmoser@mugenguild.com> * Copyright (C) 2015 Adithya Abraham Philip <adithyaphilip@gmail.com> * * 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 <http://www.gnu.org/licenses/>. */ package org.sufficientlysecure.keychain.keyimport; import android.net.Uri; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import com.squareup.okhttp.OkHttpClient; import com.squareup.okhttp.Request; import com.squareup.okhttp.Response; import org.sufficientlysecure.keychain.Constants; import org.sufficientlysecure.keychain.pgp.PgpHelper; import org.sufficientlysecure.keychain.pgp.UncachedKeyRing; import org.sufficientlysecure.keychain.pgp.UncachedPublicKey; import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException; import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils; import org.sufficientlysecure.keychain.util.Log; import java.io.IOException; import java.net.Proxy; import java.net.URL; import java.util.ArrayList; import java.util.List; import java.util.regex.Matcher; public class FacebookKeyserver extends Keyserver { private static final String FB_KEY_URL_FORMAT = "https://www.facebook.com/%s/publickey/download"; private static final String FB_HOST = "facebook.com"; private static final String FB_HOST_WWW = "www." + FB_HOST; public static final String FB_URL = "https://" + FB_HOST_WWW; public static final String ORIGIN = FB_URL; private final Proxy mProxy; public FacebookKeyserver(Proxy proxy) { mProxy = proxy; } @Override public List<ImportKeysListEntry> search(String fbUsername) throws QueryFailedException, QueryNeedsRepairException { List<ImportKeysListEntry> entry = new ArrayList<>(1); String data = get(fbUsername); // if we're here that means key retrieval succeeded, // would have thrown an exception otherwise try { UncachedKeyRing keyRing = UncachedKeyRing.decodeFromData(data.getBytes()); try { entry.add(getEntry(keyRing, fbUsername)); } catch (UnsupportedOperationException e) { Log.e(Constants.TAG, "Parsing retrieved Facebook key failed!"); } } catch (PgpGeneralException | IOException e) { Log.e(Constants.TAG, "Failed parsing key from Facebook during search", e); throw new QueryFailedException("No valid key found on Facebook"); } return entry; } @Override public String get(String fbUsername) throws QueryFailedException { Log.d(Constants.TAG, "FacebookKeyserver get: " + fbUsername + " using Proxy: " + mProxy); String data = query(fbUsername); if (data == null) { throw new QueryFailedException("data is null"); } Matcher matcher = PgpHelper.PGP_PUBLIC_KEY.matcher(data); if (matcher.find()) { return matcher.group(1); } throw new QueryFailedException("data is null"); } private String query(String fbUsername) throws QueryFailedException { try { String request = String.format(FB_KEY_URL_FORMAT, fbUsername); Log.d(Constants.TAG, "fetching from Facebook with: " + request + " proxy: " + mProxy); OkHttpClient client = new OkHttpClient(); client.setProxy(mProxy); URL url = new URL(request); Response response = client.newCall(new Request.Builder().url(url).build()).execute(); // contains body both in case of success or failure String responseBody = response.body().string(); if (response.isSuccessful()) { return responseBody; } else { // probably a 404 indicating that the key does not exist throw new QueryFailedException("key for " + fbUsername + " not found on Facebook"); } } catch (IOException e) { Log.e(Constants.TAG, "IOException at Facebook key download", e); throw new QueryFailedException("Cannot connect to Facebook. " + "Check your Internet connection!" + (mProxy == Proxy.NO_PROXY ? "" : " Using proxy " + mProxy)); } } @Override public void add(String armoredKey) throws AddKeyException { // Implementing will require usage of FB API throw new UnsupportedOperationException("Uploading keys not supported yet"); } /** * Facebook returns the entire key even during our searching phase. * * @throws UnsupportedOperationException if the key could not be parsed */ @NonNull public static ImportKeysListEntry getEntry(UncachedKeyRing ring, String fbUsername) throws UnsupportedOperationException { ImportKeysListEntry entry = new ImportKeysListEntry(); entry.setSecretKey(false); // keys imported from Facebook must be public entry.addOrigin(ORIGIN); // so we can query for the Facebook username directly, and to identify the source to // download the key from entry.setFbUsername(fbUsername); UncachedPublicKey key = ring.getPublicKey(); entry.setPrimaryUserId(key.getPrimaryUserIdWithFallback()); entry.setUserIds(key.getUnorderedUserIds()); entry.updateMergedUserIds(); entry.setPrimaryUserId(key.getPrimaryUserIdWithFallback()); entry.setKeyId(key.getKeyId()); entry.setKeyIdHex(KeyFormattingUtils.convertKeyIdToHex(key.getKeyId())); entry.setFingerprintHex(KeyFormattingUtils.convertFingerprintToHex(key.getFingerprint())); try { if (key.isEC()) { // unsupported key format (ECDH or ECDSA) Log.e(Constants.TAG, "ECDH/ECDSA key - not supported."); throw new UnsupportedOperationException("ECDH/ECDSA keys not supported yet"); } entry.setBitStrength(key.getBitStrength()); final int algorithm = key.getAlgorithm(); entry.setAlgorithm( KeyFormattingUtils.getAlgorithmInfo(algorithm, key.getBitStrength(), key.getCurveOid())); } catch (NumberFormatException | NullPointerException e) { Log.e(Constants.TAG, "Conversion for bit size, algorithm, or creation date failed.", e); // can't use this key throw new UnsupportedOperationException("Conversion for bit size, algorithm, or creation date failed."); } return entry; } public static String getUsernameFromUri(Uri uri) { // path pattern is /username/publickey/download return uri.getPathSegments().get(0); } public static boolean isFacebookHost(@Nullable Uri uri) { if (uri == null) { return false; } String host = uri.getHost(); return FB_HOST.equalsIgnoreCase(host) || FB_HOST_WWW.equalsIgnoreCase(host); } }