1 files changed, 83 insertions, 11 deletions

diff --git a/app/src/main/java/se/leap/bitmaskclient/providersetup/connectivity/DnsResolver.java b/app/src/main/java/se/leap/bitmaskclient/providersetup/connectivity/DnsResolver.java
index 5655e7b7..b50c480d 100644
--- a/app/src/main/java/se/leap/bitmaskclient/providersetup/connectivity/DnsResolver.java
+++ b/app/src/main/java/se/leap/bitmaskclient/providersetup/connectivity/DnsResolver.java
@@ -1,25 +1,63 @@
-package se.leap.bitmaskclient.providersetup.connectivity;
+ package se.leap.bitmaskclient.providersetup.connectivity;
 
-import androidx.annotation.NonNull;
+ import static java.net.InetAddress.getByName;
 
-import java.net.InetAddress;
-import java.net.UnknownHostException;
-import java.util.ArrayList;
-import java.util.List;
+ import android.util.Log;
 
-import de.blinkt.openvpn.core.VpnStatus;
-import okhttp3.Dns;
-import se.leap.bitmaskclient.base.models.Provider;
-import se.leap.bitmaskclient.base.models.ProviderObservable;
-import se.leap.bitmaskclient.base.utils.IPAddress;
+ import androidx.annotation.NonNull;
+
+ import java.net.InetAddress;
+ import java.net.UnknownHostException;
+ import java.util.ArrayList;
+ import java.util.List;
+
+ import de.blinkt.openvpn.core.VpnStatus;
+ import okhttp3.Dns;
+ import okhttp3.HttpUrl;
+ import okhttp3.OkHttpClient;
+ import okhttp3.dnsoverhttps.DnsOverHttps;
+ import se.leap.bitmaskclient.base.models.Provider;
+ import se.leap.bitmaskclient.base.models.ProviderObservable;
+ import se.leap.bitmaskclient.base.utils.IPAddress;
 
 class DnsResolver implements Dns {
+    OkHttpClient dohHttpClient;
+    boolean forceDoH;
 
+    public DnsResolver(OkHttpClient dohHttpClient, boolean forceDoH) {
+        this.dohHttpClient = dohHttpClient;
+        this.forceDoH = forceDoH;
+    }
+
+    @NonNull
     @Override
     public List<InetAddress> lookup(@NonNull String hostname) throws UnknownHostException {
+        Log.d("DNS", "trying to resolve DNS for " + hostname);
+
         try {
+            if (forceDoH) {
+                List<InetAddress> list = lookupDoH(hostname);
+                for (InetAddress address : list) {
+                    Log.d("DNS", "DoH ---> " + address.toString());
+                }
+                return list;
+            }
             return Dns.SYSTEM.lookup(hostname);
         } catch (UnknownHostException e) {
+            e.printStackTrace();
+            Log.e("DNS", "DoH via cloudflare failed");
+
+            // if not yet tried, do DNS over Https after normal DNS failed
+            if (!forceDoH) {
+                try {
+                   return lookupDoH(hostname);
+                } catch (RuntimeException uhe) {
+                   uhe.printStackTrace();
+                }
+           }
+
+            Log.d("DNS", "try hard coded IPs");
+            // let's check if there's an hard-coded IP we can use
             ProviderObservable observable = ProviderObservable.getInstance();
             Provider currentProvider;
             if (observable.getProviderForDns() != null) {
@@ -39,4 +77,38 @@ class DnsResolver implements Dns {
             }
         }
     }
+
+    private List<InetAddress> lookupDoH(@NonNull String hostname) throws RuntimeException, UnknownHostException {
+        DnsOverHttps ahablitzDoHClient = new DnsOverHttps.Builder().client(dohHttpClient)
+                .url(HttpUrl.get("https://blitz.ahadns.com"))
+                .build();
+        try {
+            Log.d("DNS", "DoH via blitz.ahadns.com");
+            return ahablitzDoHClient.lookup(hostname);
+        } catch (UnknownHostException e) {
+             e.printStackTrace();
+            Log.e("DNS", "DoH via blitz.ahadns.com failed");
+        }
+
+        DnsOverHttps googleDoHClient = new DnsOverHttps.Builder().client(dohHttpClient)
+                .url(HttpUrl.get("https://dns.google/dns-query"))
+                .bootstrapDnsHosts(getByName("8.8.4.4"), getByName("8.8.8.8"))
+                .build();
+        try {
+            Log.d("DNS", "DoH via dns.google");
+            return googleDoHClient.lookup(hostname);
+        } catch (UnknownHostException e) {
+            e.printStackTrace();
+            Log.e("DNS", "DoH via dns.google failed");
+
+        }
+
+        DnsOverHttps cloudFlareDoHClient = new DnsOverHttps.Builder().client(dohHttpClient)
+                .url(HttpUrl.get("https://1.1.1.1/dns-query"))
+                .bootstrapDnsHosts(getByName("1.1.1.1"), getByName("1.0.0.1"))
+                .build();
+
+        Log.d("DNS", "DoH via cloudflare 1.1.1.1");
+        return cloudFlareDoHClient.lookup(hostname);
+    }
 }