Add hide Magisk Manager feature

app/build.gradle

@@ -53,10 +53,11 @@ repositories {
 
 dependencies {
     implementation fileTree(include: ['*.jar'], dir: 'libs')
-    implementation 'com.android.support:recyclerview-v7:26.0.0'
-    implementation 'com.android.support:cardview-v7:26.0.0'
-    implementation 'com.android.support:design:26.0.0'
-    implementation 'com.android.support:support-v4:26.0.0'
+    implementation project(':resource')
+    implementation 'com.android.support:recyclerview-v7:26.0.1'
+    implementation 'com.android.support:cardview-v7:26.0.1'
+    implementation 'com.android.support:design:26.0.1'
+    implementation 'com.android.support:support-v4:26.0.1'
     implementation 'com.jakewharton:butterknife:8.8.1'
     implementation 'com.atlassian.commonmark:commonmark:0.9.0'
     implementation 'org.bouncycastle:bcprov-jdk15on:1.57'

app/src/main/java/com/topjohnwu/magisk/MagiskFragment.java

@@ -53,6 +53,9 @@ public class MagiskFragment extends Fragment
 
     public static final String SHOW_DIALOG = "dialog";
 
+    private static final String UNINSTALLER = "magisk_uninstaller.sh";
+    private static final String UTIL_FUNCTIONS= "util_functions.sh";
+
     private static int expandHeight = 0;
     private static boolean mExpanded = false;
 
@@ -176,8 +179,8 @@ public class MagiskFragment extends Fragment
                 .setMessage(R.string.uninstall_magisk_msg)
                 .setPositiveButton(R.string.yes, (dialogInterface, i) -> {
                     try {
-                        InputStream in = magiskManager.getAssets().open(MagiskManager.UNINSTALLER);
-                        File uninstaller = new File(magiskManager.getCacheDir(), MagiskManager.UNINSTALLER);
+                        InputStream in = magiskManager.getAssets().open(UNINSTALLER);
+                        File uninstaller = new File(magiskManager.getCacheDir(), UNINSTALLER);
                         FileOutputStream out = new FileOutputStream(uninstaller);
                         byte[] bytes = new byte[1024];
                         int read;
@@ -186,8 +189,8 @@ public class MagiskFragment extends Fragment
                         }
                         in.close();
                         out.close();
-                        in = magiskManager.getAssets().open(MagiskManager.UTIL_FUNCTIONS);
-                        File utils = new File(magiskManager.getCacheDir(), MagiskManager.UTIL_FUNCTIONS);
+                        in = magiskManager.getAssets().open(UTIL_FUNCTIONS);
+                        File utils = new File(magiskManager.getCacheDir(), UTIL_FUNCTIONS);
                         out = new FileOutputStream(utils);
                         while ((read = in.read(bytes)) != -1) {
                             out.write(bytes, 0, read);
@@ -207,8 +210,8 @@ public class MagiskFragment extends Fragment
                             public void onFinish() {
                                 progress.setMessage(getString(R.string.reboot_countdown, 0));
                                 Shell.getShell(getActivity()).su_raw(
-                                        "mv -f " + uninstaller + " /cache/" + MagiskManager.UNINSTALLER,
-                                        "mv -f " + utils + " /data/magisk/" + MagiskManager.UTIL_FUNCTIONS,
+                                        "mv -f " + uninstaller + " /cache/" + UNINSTALLER,
+                                        "mv -f " + utils + " /data/magisk/" + UTIL_FUNCTIONS,
                                         "reboot"
                                 );
                             }

app/src/main/java/com/topjohnwu/magisk/MagiskManager.java

@@ -32,8 +32,6 @@ public class MagiskManager extends Application {
     public static final String MAGISK_DISABLE_FILE = "/cache/.disable_magisk";
     public static final String TMP_FOLDER_PATH = "/dev/tmp";
     public static final String MAGISK_PATH = "/magisk";
-    public static final String UNINSTALLER = "magisk_uninstaller.sh";
-    public static final String UTIL_FUNCTIONS= "util_functions.sh";
     public static final String INTENT_SECTION = "section";
     public static final String INTENT_VERSION = "version";
     public static final String INTENT_LINK = "link";

app/src/main/java/com/topjohnwu/magisk/SettingsActivity.java

@@ -4,6 +4,7 @@ import android.content.SharedPreferences;
 import android.os.Build;
 import android.os.Bundle;
 import android.preference.ListPreference;
+import android.preference.Preference;
 import android.preference.PreferenceCategory;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceManager;
@@ -13,6 +14,7 @@ import android.support.v7.app.ActionBar;
 import android.support.v7.widget.Toolbar;
 import android.widget.Toast;
 
+import com.topjohnwu.magisk.asyncs.HideManager;
 import com.topjohnwu.magisk.components.Activity;
 import com.topjohnwu.magisk.database.SuDatabaseHelper;
 import com.topjohnwu.magisk.utils.Logger;
@@ -98,6 +100,7 @@ public class SettingsActivity extends Activity implements Topic.Subscriber {
             multiuserMode = (ListPreference) findPreference("multiuser_mode");
             namespaceMode = (ListPreference) findPreference("mnt_ns");
             SwitchPreference reauth = (SwitchPreference) findPreference("su_reauth");
+            Preference hideManager = findPreference("hide");
 
             setSummary();
 
@@ -105,6 +108,7 @@ public class SettingsActivity extends Activity implements Topic.Subscriber {
             if (getActivity().getApplicationInfo().uid > 99999) {
                 prefScreen.removePreference(magiskCategory);
                 prefScreen.removePreference(suCategory);
+                generalCatagory.removePreference(hideManager);
             }
 
             // Remove re-authentication option on Android O, it will not work
@@ -117,6 +121,11 @@ public class SettingsActivity extends Activity implements Topic.Subscriber {
                 return true;
             });
 
+            hideManager.setOnPreferenceClickListener((pref) -> {
+                new HideManager(getActivity()).exec();
+                return true;
+            });
+
             if (!BuildConfig.DEBUG) {
                 prefScreen.removePreference(developer);
             }

app/src/main/java/com/topjohnwu/magisk/asyncs/HideManager.java

@@ -0,0 +1,72 @@
+package com.topjohnwu.magisk.asyncs;
+
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.widget.Toast;
+
+import com.topjohnwu.magisk.MagiskManager;
+import com.topjohnwu.magisk.R;
+import com.topjohnwu.magisk.superuser.Policy;
+import com.topjohnwu.magisk.utils.Utils;
+import com.topjohnwu.magisk.utils.ZipUtils;
+
+import java.io.File;
+import java.util.List;
+
+public class HideManager extends ParallelTask<Void, Void, Boolean> {
+
+    public HideManager(Context context) {
+        super(context);
+    }
+
+    @Override
+    protected void onPreExecute() {
+        getMagiskManager().toast(R.string.hide_manager_toast, Toast.LENGTH_SHORT);
+    }
+
+    @Override
+    protected Boolean doInBackground(Void... voids) {
+        MagiskManager magiskManager = getMagiskManager();
+        if (magiskManager == null)
+            return false;
+
+        // Generate a new unhide app with random package name
+        File unhideAPK = new File(magiskManager.getCacheDir(), "unhide.apk");
+        String pkg = ZipUtils.generateUnhide(magiskManager, unhideAPK);
+
+        // Install the application
+        List<String> ret = getShell().su("pm install " + unhideAPK + ">/dev/null && echo true || echo false");
+        unhideAPK.delete();
+        if (!Utils.isValidShellResponse(ret) || !Boolean.parseBoolean(ret.get(0)))
+            return false;
+
+        try {
+            // Allow the application to gain root by default
+            PackageManager pm = magiskManager.getPackageManager();
+            int uid = pm.getApplicationInfo(pkg, 0).uid;
+            Policy policy = new Policy(uid, pm);
+            policy.policy = Policy.ALLOW;
+            policy.notification = false;
+            policy.logging = false;
+            magiskManager.suDB.addPolicy(policy);
+        } catch (PackageManager.NameNotFoundException e) {
+            e.printStackTrace();
+            return false;
+        }
+
+        // Hide myself!
+        getShell().su_raw("pm hide " + magiskManager.getPackageName());
+        return true;
+    }
+
+    @Override
+    protected void onPostExecute(Boolean b) {
+        MagiskManager magiskManager = getMagiskManager();
+        if (magiskManager == null)
+            return;
+        if (!b) {
+            magiskManager.toast(R.string.hide_manager_fail_toast, Toast.LENGTH_LONG);
+        }
+        super.onPostExecute(b);
+    }
+}

app/src/main/java/com/topjohnwu/magisk/utils/Utils.java

@@ -35,6 +35,7 @@ import com.topjohnwu.magisk.receivers.DownloadReceiver;
 import com.topjohnwu.magisk.receivers.ManagerUpdate;
 
 import java.io.File;
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashSet;
@@ -288,4 +289,25 @@ public class Utils {
 
         return locales;
     }
+
+    public static String genPackageName(String prefix, int length) {
+        StringBuilder builder = new StringBuilder(length);
+        builder.append(prefix);
+        length -= prefix.length();
+        SecureRandom random = new SecureRandom();
+        String base = "abcdefghijklmnopqrstuvwxyz";
+        String alpha = base + base.toUpperCase();
+        String full = alpha + "0123456789..........";
+        char next, prev = '\0';
+        for (int i = 0; i < length; ++i) {
+            if (prev == '.' || i == length - 1 || i == 0) {
+                next = alpha.charAt(random.nextInt(alpha.length()));
+            } else {
+                next = full.charAt(random.nextInt(full.length()));
+            }
+            builder.append(next);
+            prev = next;
+        }
+        return builder.toString();
+    }
 }

app/src/main/java/com/topjohnwu/magisk/utils/ZipUtils.java

@@ -1,6 +1,7 @@
 package com.topjohnwu.magisk.utils;
 
 import android.content.Context;
+import android.text.TextUtils;
 
 import org.bouncycastle.asn1.ASN1InputStream;
 import org.bouncycastle.asn1.ASN1ObjectIdentifier;
@@ -65,6 +66,7 @@ public class ZipUtils {
     // File name in assets
     private static final String PUBLIC_KEY_NAME = "public.certificate.x509.pem";
     private static final String PRIVATE_KEY_NAME = "private.key.pk8";
+    private static final String UNHIDE_NAME = "unhide.apk";
 
     private static final String CERT_SF_NAME = "META-INF/CERT.SF";
     private static final String CERT_SIG_NAME = "META-INF/CERT.%s";
@@ -82,6 +84,45 @@ public class ZipUtils {
 
     public native static void zipAdjust(String filenameIn, String filenameOut);
 
+    public static String generateUnhide(Context context, File output) {
+        File temp = new File(context.getCacheDir(), "temp.apk");
+        String pkg = "";
+        try {
+            JarInputStream source = new JarInputStream(context.getAssets().open(UNHIDE_NAME));
+            JarOutputStream dest = new JarOutputStream(new FileOutputStream(temp));
+            JarEntry entry;
+            int size;
+            byte buffer[] = new byte[4096];
+            while ((entry = source.getNextJarEntry()) != null) {
+                dest.putNextEntry(new JarEntry(entry.getName()));
+                if (TextUtils.equals(entry.getName(), "AndroidManifest.xml")) {
+                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                    while((size = source.read(buffer)) != -1) {
+                        baos.write(buffer, 0, size);
+                    }
+                    byte xml[] = baos.toByteArray();
+                    pkg = Utils.genPackageName("com.", 20);
+                    for (int i = 0; i < 20; ++i) {
+                        xml[424 + i] = (byte) pkg.charAt(i);
+                    }
+                    dest.write(xml);
+                } else {
+                    while((size = source.read(buffer)) != -1) {
+                        dest.write(buffer, 0, size);
+                    }
+                }
+            }
+            source.close();
+            dest.close();
+            signZip(context, temp, output, false);
+            temp.delete();
+        } catch (IOException e) {
+            e.printStackTrace();
+            return pkg;
+        }
+        return pkg;
+    }
+
     public static void removeTopFolder(InputStream in, File output) throws IOException {
         try {
             JarInputStream source = new JarInputStream(in);
@@ -102,7 +143,7 @@ public class ZipUtils {
                     continue;
                 }
                 dest.putNextEntry(new JarEntry(path));
-                while((size = source.read(buffer, 0, 2048)) != -1) {
+                while((size = source.read(buffer)) != -1) {
                     dest.write(buffer, 0, size);
                 }
             }

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

@@ -136,6 +136,8 @@
     <string name="manager_download_install">Press to download and install</string>
     <string name="magisk_updates">Magisk Updates</string>
     <string name="flashing">Flashing</string>
+    <string name="hide_manager_toast">Hiding Magisk Manager…</string>
+    <string name="hide_manager_fail_toast">Hide Magisk Manager failed…</string>
 
     <!--Settings Activity -->
     <string name="settings_general_category">General</string>
@@ -145,6 +147,8 @@
     <string name="settings_notification_summary">Show update notifications when new version is available</string>
     <string name="settings_clear_cache_title">Clear Repo Cache</string>
     <string name="settings_clear_cache_summary">Clear the cached information for online repos, forces the app to refresh online</string>
+    <string name="settings_hide_manager_title">Hide Magisk Manager</string>
+    <string name="settings_hide_manager_summary">Temporarily hide Magisk Manager.\nThis will install a new app called \"Unhide Magisk Manager\"</string>
     <string name="language">Language</string>
     <string name="system_default">(System Default)</string>
 

app/src/main/res/xml/app_settings.xml

@@ -20,6 +20,11 @@
             android:title="@string/settings_clear_cache_title"
             android:summary="@string/settings_clear_cache_summary" />
 
+        <Preference
+            android:key="hide"
+            android:title="@string/settings_hide_manager_title"
+            android:summary="@string/settings_hide_manager_summary" />
+
     </PreferenceCategory>
 
     <PreferenceCategory