65 lines
2.2 KiB
Java
65 lines
2.2 KiB
Java
/*
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* Copyright (C) 2018 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package android.net;
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import android.annotation.NonNull;
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import android.util.Log;
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import java.io.IOException;
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import java.net.InetSocketAddress;
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import javax.net.SocketFactory;
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import javax.net.ssl.SSLSocket;
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import javax.net.ssl.SSLSocketFactory;
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/**
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* Class for testing connectivity to DNS-over-TLS servers.
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* {@hide}
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*/
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public class PrivateDnsConnectivityChecker {
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private static final String TAG = "NetworkUtils";
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private static final int PRIVATE_DNS_PORT = 853;
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private static final int CONNECTION_TIMEOUT_MS = 5000;
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private PrivateDnsConnectivityChecker() { }
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/**
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* checks that a provided host can perform a TLS handshake on port 853.
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* @param hostname host to connect to.
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*/
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public static boolean canConnectToPrivateDnsServer(@NonNull String hostname) {
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final SocketFactory factory = SSLSocketFactory.getDefault();
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TrafficStats.setThreadStatsTagApp();
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try (SSLSocket socket = (SSLSocket) factory.createSocket()) {
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socket.setSoTimeout(CONNECTION_TIMEOUT_MS);
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socket.connect(new InetSocketAddress(hostname, PRIVATE_DNS_PORT));
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if (!socket.isConnected()) {
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Log.w(TAG, String.format("Connection to %s failed.", hostname));
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return false;
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}
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socket.startHandshake();
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Log.w(TAG, String.format("TLS handshake to %s succeeded.", hostname));
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return true;
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} catch (IOException e) {
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Log.w(TAG, String.format("TLS handshake to %s failed.", hostname), e);
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return false;
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}
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}
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}
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