Merge branch 'obfs4_no_udp_no_ipv6' into 'master'

Obfs4: no udp no ipv6

See merge request leap/bitmask_android!142

2 files changed, 61 insertions, 5 deletions

diff --git a/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java b/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java
index 4248072a..64b51960 100644
--- a/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java
+++ b/app/src/main/java/se/leap/bitmaskclient/base/utils/ConfigHelper.java
@@ -20,6 +20,7 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.os.Build;
 import android.os.Looper;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
@@ -44,10 +45,12 @@ import java.security.interfaces.RSAPrivateKey;
 import java.security.spec.InvalidKeySpecException;
 import java.security.spec.PKCS8EncodedKeySpec;
 import java.util.Calendar;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import se.leap.bitmaskclient.BuildConfig;
-import se.leap.bitmaskclient.providersetup.ProviderAPI;
 import se.leap.bitmaskclient.R;
+import se.leap.bitmaskclient.providersetup.ProviderAPI;
 
 import static se.leap.bitmaskclient.base.models.Constants.DEFAULT_BITMASK;
 
@@ -62,6 +65,7 @@ public class ConfigHelper {
     final public static String NG_1024 =
             "eeaf0ab9adb38dd69c33f80afa8fc5e86072618775ff3c0b9ea2314c9c256576d674df7496ea81d3383b4813d692c6e0e0d5d8e250b98be48e495c1d6089dad15dc7d7b46154d6b6ce8ef4ad69b15d4982559b297bcf1885c529f566660e57ec68edbc3c05726cc02fd4cbf4976eaa9afd5138fe8376435b9fc61d2fc0eb06e3";
     final public static BigInteger G = new BigInteger("2");
+    final public static Pattern IPv4_PATTERN = Pattern.compile("^(?:(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\\.){3}(?:25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])$");
 
     public static boolean checkErroneousDownload(String downloadedString) {
         try {
@@ -203,6 +207,8 @@ public class ConfigHelper {
                 (string1 != null && string1.equals(string2));
     }
 
+    @SuppressWarnings("unused")
+    // FatWeb Flavor uses that for auto-update
     public static String getApkFileName() {
         try {
             return BuildConfig.update_apk_url.substring(BuildConfig.update_apk_url.lastIndexOf("/"));
@@ -211,6 +217,8 @@ public class ConfigHelper {
         }
     }
 
+    @SuppressWarnings("unused")
+    // FatWeb Flavor uses that for auto-update
     public static String getVersionFileName() {
         try {
             return BuildConfig.version_file_url.substring(BuildConfig.version_file_url.lastIndexOf("/"));
@@ -219,6 +227,8 @@ public class ConfigHelper {
         }
     }
 
+    @SuppressWarnings("unused")
+    // FatWeb Flavor uses that for auto-update
     public static String getSignatureFileName() {
         try {
             return BuildConfig.signature_url.substring(BuildConfig.signature_url.lastIndexOf("/"));
@@ -227,4 +237,12 @@ public class ConfigHelper {
         }
     }
 
+    public static boolean isIPv4(String ipv4) {
+        if (ipv4 == null) {
+            return false;
+        }
+        Matcher matcher = IPv4_PATTERN.matcher(ipv4);
+        return matcher.matches();
+    }
+
 }
diff --git a/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java b/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java
index 6fffb403..d72f0936 100644
--- a/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java
+++ b/app/src/main/java/se/leap/bitmaskclient/eip/VpnConfigGenerator.java
@@ -29,8 +29,10 @@ import java.util.Iterator;
 
 import de.blinkt.openvpn.VpnProfile;
 import de.blinkt.openvpn.core.ConfigParser;
+import de.blinkt.openvpn.core.VpnStatus;
 import de.blinkt.openvpn.core.connection.Connection;
 import se.leap.bitmaskclient.base.models.Provider;
+import se.leap.bitmaskclient.base.utils.ConfigHelper;
 import se.leap.bitmaskclient.pluggableTransports.Obfs4Options;
 
 import static de.blinkt.openvpn.core.connection.Connection.TransportType.OBFS4;
@@ -95,7 +97,11 @@ public class VpnConfigGenerator {
         HashMap<Connection.TransportType, VpnProfile> profiles = new HashMap<>();
         profiles.put(OPENVPN, createProfile(OPENVPN));
         if (supportsObfs4()) {
-            profiles.put(OBFS4, createProfile(OBFS4));
+            try {
+                profiles.put(OBFS4, createProfile(OBFS4));
+            } catch (ConfigParser.ConfigParseError | NumberFormatException | JSONException | IOException e) {
+                e.printStackTrace();
+            }
         }
         return profiles;
     }
@@ -162,16 +168,18 @@ public class VpnConfigGenerator {
 
         StringBuilder stringBuilder = new StringBuilder();
         try {
-            String ipAddress = gateway.getString(IP_ADDRESS);
+            String ipAddress = null;
             JSONObject capabilities = gateway.getJSONObject(CAPABILITIES);
             switch (apiVersion) {
                 default:
                 case 1:
                 case 2:
+                     ipAddress = gateway.getString(IP_ADDRESS);
                     gatewayConfigApiv1(stringBuilder, ipAddress, capabilities);
                     break;
                 case 3:
                 case 4:
+                    ipAddress = gateway.optString(IP_ADDRESS);
                     String ipAddress6 = gateway.optString(IP_ADDRESS6);
                     String[] ipAddresses = ipAddress6.isEmpty()  ?
                             new String[]{ipAddress} :
@@ -189,6 +197,7 @@ public class VpnConfigGenerator {
         if (remotes.endsWith(newLine)) {
             remotes = remotes.substring(0, remotes.lastIndexOf(newLine));
         }
+
         return remotes;
     }
 
@@ -247,6 +256,7 @@ public class VpnConfigGenerator {
 
     private void obfs4GatewayConfigMinApiv3(StringBuilder stringBuilder, String[] ipAddresses, JSONArray transports) throws JSONException {
         JSONObject obfs4Transport = getTransport(transports, OBFS4);
+        JSONArray protocols = obfs4Transport.getJSONArray(PROTOCOLS);
         //for now only use ipv4 gateway the syntax route remote_host 255.255.255.255 net_gateway is not yet working
         // https://community.openvpn.net/openvpn/ticket/1161
         /*for (String ipAddress : ipAddresses) {
@@ -258,10 +268,38 @@ public class VpnConfigGenerator {
             return;
         }
 
-        String ipAddress = ipAddresses[ipAddresses.length - 1];
+        // check if at least one address is IPv4, IPv6 is currently not supported for obfs4
+        String ipAddress = null;
+        for (String address : ipAddresses) {
+            if (ConfigHelper.isIPv4(address)) {
+                ipAddress = address;
+                break;
+            }
+            VpnStatus.logWarning("Skipping IP address " + address + " while configuring obfs4.");
+        }
+
+        if (ipAddress == null) {
+            VpnStatus.logError("No matching IPv4 address found to configure obfs4.");
+            return;
+        }
+
+        // check if at least one protocol is TCP, UDP is currently not supported for obfs4
+        boolean hasTcp = false;
+        for (int i = 0; i < protocols.length(); i++) {
+            String protocol = protocols.getString(i);
+            if (protocol.contains("tcp")) {
+                hasTcp = true;
+            }
+        }
+
+        if (!hasTcp) {
+            VpnStatus.logError("obfs4 currently only allows TCP! Skipping obfs4 config for ip " + ipAddress);
+            return;
+        }
+
         String route = "route " + ipAddress + " 255.255.255.255 net_gateway" + newLine;
         stringBuilder.append(route);
-        String remote = REMOTE + " " + DISPATCHER_IP + " " + DISPATCHER_PORT + " " + obfs4Transport.getJSONArray(PROTOCOLS).getString(0) + newLine;
+        String remote = REMOTE + " " + DISPATCHER_IP + " " + DISPATCHER_PORT + " tcp" + newLine;
         stringBuilder.append(remote);
     }