add expert option to send debug version/UUID on each HTTP download

When debugging issues, tracking the client can be quite useful.  This makes
an "Expert" preference that adds the app version and a randomly generated,
stored UUID to the query string each time it downloads an index or an app
package.

This is also useful in whitelabeling, for use cases where there needs to be
some kind of identifier to make it work.

app/src/basic/res/xml/preferences.xml

@@ -150,6 +150,12 @@
                 android:summary="@string/hide_all_notifications_summary"
                 android:defaultValue="false"
                 android:dependency="expert"/>
+        <CheckBoxPreference
+                android:key="sendVersionAndUUIDToServers"
+                android:title="@string/send_version_and_uuid"
+                android:summary="@string/send_version_and_uuid_summary"
+                android:defaultValue="false"
+                android:dependency="expert"/>
         <CheckBoxPreference
                 android:key="forceOldIndex"
                 android:title="@string/force_old_index"

app/src/main/java/org/fdroid/fdroid/FDroidApp.java

@@ -1,5 +1,9 @@
 /*
- * Copyright (C) 2010-12  Ciaran Gultnieks, ciaran@ciarang.com
+ * Copyright (C) 2010-2012  Ciaran Gultnieks, ciaran@ciarang.com
+ * Copyright (C) 2013-2016  Peter Serwylo <peter@serwylo.com>
+ * Copyright (C) 2014-2018  Hans-Christoph Steiner <hans@eds.org>
+ * Copyright (C) 2015-2016  Daniel Martí <mvdan@mvdan.cc>
+ * Copyright (c) 2018  Senecto Limited
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -33,11 +37,13 @@ import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
+import android.net.Uri;
 import android.os.Build;
 import android.os.Environment;
 import android.os.StrictMode;
 import android.support.v4.util.LongSparseArray;
 import android.text.TextUtils;
+import android.util.Base64;
 import android.util.Log;
 import android.view.Display;
 import android.view.WindowManager;
@@ -66,14 +72,17 @@ import org.fdroid.fdroid.data.RepoProvider;
 import org.fdroid.fdroid.installer.ApkFileProvider;
 import org.fdroid.fdroid.installer.InstallHistoryService;
 import org.fdroid.fdroid.net.ConnectivityMonitorService;
+import org.fdroid.fdroid.net.HttpDownloader;
 import org.fdroid.fdroid.net.ImageLoaderForUIL;
 import org.fdroid.fdroid.net.WifiStateChangeService;
 import org.fdroid.fdroid.views.hiding.HidingManager;
 
 import javax.microedition.khronos.opengles.GL10;
 import java.io.IOException;
+import java.nio.ByteBuffer;
 import java.security.Security;
 import java.util.List;
+import java.util.UUID;
 
 @ReportsCrashes(mailTo = "reports@f-droid.org",
         mode = ReportingInteractionMode.DIALOG,
@@ -480,6 +489,30 @@ public class FDroidApp extends Application {
             UpdateService.forceUpdateRepo(this);
         }
         atStartTime.edit().putInt("build-version", Build.VERSION.SDK_INT).apply();
+
+        final String queryStringKey = "http-downloader-query-string";
+        if (Preferences.get().sendVersionAndUUIDToServers()) {
+            HttpDownloader.queryString = atStartTime.getString(queryStringKey, null);
+            if (HttpDownloader.queryString == null) {
+                UUID uuid = UUID.randomUUID();
+                ByteBuffer buffer = ByteBuffer.allocate(Long.SIZE / Byte.SIZE * 2);
+                buffer.putLong(uuid.getMostSignificantBits());
+                buffer.putLong(uuid.getLeastSignificantBits());
+                String id = Base64.encodeToString(buffer.array(),
+                        Base64.URL_SAFE | Base64.NO_WRAP | Base64.NO_PADDING);
+                StringBuilder builder = new StringBuilder("id=").append(id);
+                String versionName = Uri.encode(Utils.getVersionName(this));
+                if (versionName != null) {
+                    builder.append("&client_version=").append(versionName);
+                }
+                HttpDownloader.queryString = builder.toString();
+            }
+            if (!atStartTime.contains(queryStringKey)) {
+                atStartTime.edit().putString(queryStringKey, HttpDownloader.queryString).apply();
+            }
+        } else {
+            atStartTime.edit().remove(queryStringKey).apply();
+        }
     }
 
     /**

app/src/main/java/org/fdroid/fdroid/Preferences.java

@@ -106,6 +106,7 @@ public final class Preferences implements SharedPreferences.OnSharedPreferenceCh
     public static final String PREF_PANIC_HIDE = "pref_panic_hide";
     public static final String PREF_HIDE_ON_LONG_PRESS_SEARCH = "hideOnLongPressSearch";
     public static final String PREF_HIDE_ALL_NOTIFICATIONS = "hideAllNotifications";
+    public static final String PREF_SEND_VERSION_AND_UUID_TO_SERVERS = "sendVersionAndUUIDToServers";
 
     public static final int OVER_NETWORK_NEVER = 0;
     public static final int OVER_NETWORK_ON_DEMAND = 1;
@@ -498,6 +499,14 @@ public final class Preferences implements SharedPreferences.OnSharedPreferenceCh
         return preferences.getBoolean(PREF_HIDE_ALL_NOTIFICATIONS, IGNORED_B);
     }
 
+    /**
+     * Whether to include the version of this app and a randomly generated ID
+     * to the server when downloading from it.
+     */
+    public boolean sendVersionAndUUIDToServers() {
+        return preferences.getBoolean(PREF_SEND_VERSION_AND_UUID_TO_SERVERS, IGNORED_B);
+    }
+
     /**
      * This is cached as it is called several times inside app list adapters.
      * Providing it here means the shared preferences file only needs to be

app/src/main/java/org/fdroid/fdroid/RepoUpdater.java

@@ -111,12 +111,7 @@ public class RepoUpdater {
     }
 
     protected String getIndexUrl(@NonNull Repo repo) {
-        String url = repo.address + "/index.jar";
+        return repo.address + "/index.jar";
-        String versionName = Utils.getVersionName(context);
-        if (versionName != null) {
-            url += "?client_version=" + versionName;
-        }
-        return url;
     }
 
     public boolean hasChanged() {

app/src/main/java/org/fdroid/fdroid/net/HttpDownloader.java

@@ -1,3 +1,24 @@
+/*
+ * Copyright (C) 2014-2017  Peter Serwylo <peter@serwylo.com>
+ * Copyright (C) 2014-2018  Hans-Christoph Steiner <hans@eds.org>
+ * Copyright (C) 2015-2016  Daniel Martí <mvdan@mvdan.cc>
+ * Copyright (c) 2018  Senecto Limited
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
 package org.fdroid.fdroid.net;
 
 import android.annotation.TargetApi;
@@ -40,6 +61,11 @@ public class HttpDownloader extends Downloader {
     private HttpURLConnection connection;
     private boolean newFileAvailableOnServer;
 
+    /**
+     * String to append to all HTTP downloads, created in {@link FDroidApp#onCreate()}
+     */
+    public static String queryString;
+
     HttpDownloader(Uri uri, File destFile)
             throws FileNotFoundException, MalformedURLException {
         this(uri, destFile, null, null);
@@ -142,7 +168,11 @@ public class HttpDownloader extends Downloader {
             // swap never works with a proxy, its unrouted IP on the same subnet
             connection = (HttpURLConnection) sourceUrl.openConnection();
         } else {
-            connection = NetCipher.getHttpURLConnection(sourceUrl);
+            if (queryString != null) {
+                connection = NetCipher.getHttpURLConnection(new URL(urlString + "?" + queryString));
+            } else {
+                connection = NetCipher.getHttpURLConnection(sourceUrl);
+            }
         }
 
         connection.setRequestProperty("User-Agent", "F-Droid " + BuildConfig.VERSION_NAME);

app/src/main/res/values/strings.xml

@@ -22,6 +22,9 @@
     </string>
     <string name="keep_install_history">Keep install history</string>
     <string name="keep_install_history_summary">Store a log of all installs and uninstalls in a private store</string>
+    <string name="send_version_and_uuid">Send version and UUID to servers</string>
+    <string name="send_version_and_uuid_summary">Include this app\'s version and a random, unique ID when
+        downloading, takes affect next app restart.</string>
     <string name="force_old_index">Force old index format</string>
     <string name="force_old_index_summary">In case there are bugs or compatibility issues, use the XML app index</string>
     <string name="other">Other</string>

app/src/main/res/xml/preferences.xml

@@ -171,6 +171,12 @@
                 android:summary="@string/hide_all_notifications_summary"
                 android:defaultValue="false"
                 android:dependency="expert"/>
+        <CheckBoxPreference
+                android:key="sendVersionAndUUIDToServers"
+                android:title="@string/send_version_and_uuid"
+                android:summary="@string/send_version_and_uuid_summary"
+                android:defaultValue="false"
+                android:dependency="expert"/>
         <CheckBoxPreference
                 android:key="forceOldIndex"
                 android:title="@string/force_old_index"