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package de.pixart.messenger.utils;
import android.content.Context;
import android.support.annotation.NonNull;
import android.util.Log;
import java.io.IOException;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import de.measite.minidns.DNSClient;
import de.measite.minidns.DNSName;
import de.measite.minidns.dnssec.DNSSECResultNotAuthenticException;
import de.measite.minidns.hla.DnssecResolverApi;
import de.measite.minidns.hla.ResolverApi;
import de.measite.minidns.hla.ResolverResult;
import de.measite.minidns.record.A;
import de.measite.minidns.record.AAAA;
import de.measite.minidns.record.Data;
import de.measite.minidns.record.InternetAddressRR;
import de.measite.minidns.record.SRV;
import de.pixart.messenger.Config;
public class Resolver {
private static final String DIRECT_TLS_SERVICE = "_xmpps-client";
private static final String STARTTLS_SERICE = "_xmpp-client";
public static void registerLookupMechanism(Context context) {
DNSClient.addDnsServerLookupMechanism(new AndroidUsingLinkProperties(context));
}
public static List<Result> resolve(String domain) {
List<Result> results = new ArrayList<>();
try {
results.addAll(resolveSrv(domain, true));
} catch (IOException e) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": " + e.getMessage());
}
try {
results.addAll(resolveSrv(domain, false));
} catch (IOException e) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": " + e.getMessage());
}
if (results.size() == 0) {
results.add(Result.createDefault(domain));
}
Collections.sort(results);
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": " + results.toString());
return results;
}
private static List<Result> resolveSrv(String domain, final boolean directTls) throws IOException {
if (Thread.interrupted()) {
return Collections.emptyList();
}
DNSName dnsName = DNSName.from((directTls ? DIRECT_TLS_SERVICE : STARTTLS_SERICE) + "._tcp." + domain);
ResolverResult<SRV> result = resolveWithFallback(dnsName, SRV.class);
List<Result> results = new ArrayList<>();
for (SRV record : result.getAnswersOrEmptySet()) {
final boolean addedIPv4 = results.addAll(resolveIp(record, A.class, result.isAuthenticData(), directTls));
results.addAll(resolveIp(record, AAAA.class, result.isAuthenticData(), directTls));
if (!addedIPv4 && !Thread.interrupted()) {
Result resolverResult = Result.fromRecord(record, directTls);
resolverResult.authenticated = resolverResult.isAuthenticated();
results.add(resolverResult);
}
}
return results;
}
private static <D extends InternetAddressRR> List<Result> resolveIp(SRV srv, Class<D> type, boolean authenticated, boolean directTls) {
if (Thread.interrupted()) {
return Collections.emptyList();
}
List<Result> list = new ArrayList<>();
try {
ResolverResult<D> results = resolveWithFallback(srv.name, type);
for (D record : results.getAnswersOrEmptySet()) {
Result resolverResult = Result.fromRecord(srv, directTls);
resolverResult.authenticated = results.isAuthenticData() && authenticated;
resolverResult.ip = record.getInetAddress();
list.add(resolverResult);
}
} catch (Throwable t) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " " + t.getMessage());
}
return list;
}
private static <D extends Data> ResolverResult<D> resolveWithFallback(DNSName dnsName, Class<D> type) throws IOException {
try {
final ResolverResult<D> r = DnssecResolverApi.INSTANCE.resolveDnssecReliable(dnsName, type);
if (r.wasSuccessful()) {
if (r.getAnswers().isEmpty() && type.equals(SRV.class)) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": resolving SRV records of " + dnsName.toString() + " with DNSSEC yielded empty result");
}
return r;
}
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " with DNSSEC. Trying DNS instead.", r.getResolutionUnsuccessfulException());
} catch (DNSSECResultNotAuthenticException e) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " with DNSSEC. Trying DNS instead.", e);
} catch (IOException e) {
throw e;
} catch (Throwable throwable) {
Log.d(Config.LOGTAG, Resolver.class.getSimpleName() + ": error resolving " + type.getSimpleName() + " with DNSSEC. Trying DNS instead.", throwable);
}
return ResolverApi.INSTANCE.resolve(dnsName, type);
}
public static class Result implements Comparable<Result> {
private InetAddress ip;
private DNSName hostname;
private int port = 5222;
private boolean directTls = false;
private boolean authenticated = false;
private int priority;
public InetAddress getIp() {
return ip;
}
public int getPort() {
return port;
}
public DNSName getHostname() {
return hostname;
}
public boolean isDirectTls() {
return directTls;
}
public boolean isAuthenticated() {
return authenticated;
}
@Override
public String toString() {
return "Result{" +
"ip='" + (ip == null ? null : ip.getHostAddress()) + '\'' +
", hostame='" + hostname.toString() + '\'' +
", port=" + port +
", directTls=" + directTls +
", authenticated=" + authenticated +
", priority=" + priority +
'}';
}
@Override
public int compareTo(@NonNull Result result) {
if (result.priority == priority) {
if (directTls == result.directTls) {
if (ip == null && result.ip == null) {
return 0;
} else if (ip != null && result.ip != null) {
if (ip instanceof Inet4Address && result.ip instanceof Inet4Address) {
return 0;
} else {
return ip instanceof Inet4Address ? -1 : 1;
}
} else {
return ip != null ? -1 : 1;
}
} else {
return directTls ? -1 : 1;
}
} else {
return priority - result.priority;
}
}
public static Result fromRecord(SRV srv, boolean directTls) {
Result result = new Result();
result.port = srv.port;
result.hostname = srv.name;
result.directTls = directTls;
result.priority = srv.priority;
return result;
}
public static Result createDefault(String domain) {
Result result = new Result();
result.port = 5222;
result.hostname = DNSName.from(domain);
return result;
}
}
}
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