From 005f962271b6389922e4119f49a867a9621b1e41 Mon Sep 17 00:00:00 2001
From: Julian Schmuckli <julian@schmuckli.net>
Date: Fri, 3 Aug 2018 12:16:10 +0800
Subject: [PATCH 1/5] Added QR Code generation in settings for TOTP

---
 .idea/caches/build_file_checksums.ser         | Bin 537 -> 536 bytes
 app/build.gradle                              |   1 +
 .../coderbunker/kioskapp/KioskActivity.java   |  36 ++--
 .../kioskapp/SettingsActivity.java            |  79 ++++++--
 .../com/coderbunker/kioskapp/lib/Base32.java  | 176 ++++++++++++++++++
 app/src/main/res/layout/activity_settings.xml |  16 +-
 app/src/main/res/layout/password_dialog.xml   |  14 ++
 7 files changed, 283 insertions(+), 39 deletions(-)
 create mode 100644 app/src/main/java/com/coderbunker/kioskapp/lib/Base32.java

diff --git a/.idea/caches/build_file_checksums.ser b/.idea/caches/build_file_checksums.ser
index 574d9121d27189faf6ca171181da59cc59d02179..d9501ab451e0815b2578abb30cd2a41e69556a2e 100644
GIT binary patch
delta 208
zcmbQqGJ|Ep43@vA!rUg#@eklHPAw_P%u6rUOD{@H$w@6OVql7PTJu@_2OCGo111KB
ziUI}(27%@Oqz+Ha-1<}_DlRxpUsbw<L0vzzIJKx)KdUq+Gcives$GBbTSn>0EsUB1
z%BLr9PSc8>Xn8SS=aPO&_T;^cvI1*6ZeI_%zF+ypKF{;|c^m2`zhacL6WCoAaQ?04
z4~ta}2MazW>6b7FBo-9tCzWRAq`+KN$WX_?26D(>&HTs@j=iVnuUR%Fg~M5=0sszk
BQeFT6

delta 210
zcmbQiGLvP(43^UpIt3Hw_}2?078JxJm1gFo=%p7WrsSlS7BMhIJFWRF{)3Gp<N*@{
zLq!1t1B1W>r>d6JIrq>1?-SL1`>w^jgn_>}wWK67FTEJ1v5=vTfeoZ~-pz!4Huu@{
zbQAQX!krE;EMd@awu%WYPAw{qaVn}z%!`3)iAkS)fKh647^9{@Rx|&p9ga2mXT!4d
zj`_9knB31OD<Eg+_v%fFvEK#vjwj3Y?sQGw!zd^CxtDp>o`j`-n{3mJpPdy*ssI3I
C!BPtV

diff --git a/app/build.gradle b/app/build.gradle
index a76f02d..e102807 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -23,6 +23,7 @@ dependencies {
     implementation 'com.android.support:appcompat-v7:27.0.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.2'
     implementation 'com.android.support:support-v4:27.1.1'
+    implementation 'com.journeyapps:zxing-android-embedded:3.6.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
diff --git a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
index a1b0de2..62ec944 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
@@ -24,7 +24,7 @@
 public class KioskActivity extends Activity {
 
     private final Context context = this;
-    private  WebView webView;
+    private WebView webView;
     private static String password = "1234";
     private static String URL = "https://naibaben.github.io/";
 
@@ -35,7 +35,7 @@ public class KioskActivity extends Activity {
     private boolean locked = false;
     private Dialog dialog;
 
-    private Button b1, b2, b3, b4;
+    private Button b1, b2, b3, b4, b5, b6;
     private Button n0, n1, n2, n3, n4, n5, n6, n7, n8, n9;
     private ArrayList<Button> numbers;
 
@@ -45,7 +45,7 @@ public class KioskActivity extends Activity {
 
     @Override
     public void onBackPressed() {
-     //Do nothing...
+        //Do nothing...
     }
 
     @Override
@@ -77,7 +77,7 @@ protected void onCreate(Bundle savedInstanceState) {
             public boolean onTouch(View view, MotionEvent motionEvent) {
                 hideSystemUI();
 
-                if(!dialogPrompted && locked) {
+                if (!dialogPrompted && locked) {
                     askPassword();
                     return true;
                 } else
@@ -133,26 +133,18 @@ private void hideNavBar(View view) {
     }
 
 
-
-
     @Override
     public void onWindowFocusChanged(boolean hasFocus) {
         super.onWindowFocusChanged(hasFocus);
         if (hasFocus) {
             hideSystemUI();
-        }else{
+        } else {
             hideSystemUI();
         }
     }
 
 
-    public static void setPassword(String newPwd)
-    {
-        password = newPwd;
-    }
-
-    public static void setURL(String newURL)
-    {
+    public static void setURL(String newURL) {
         URL = newURL;
     }
 
@@ -171,9 +163,15 @@ public void enterNumber(String number) {
             case 3:
                 b4.setText(number);
                 break;
+            case 4:
+                b5.setText(number);
+                break;
+            case 5:
+                b6.setText(number);
+                break;
         }
 
-        if (cptPwd == 3) {
+        if (cptPwd == 5) {
             cptPwd = 0;
             checkPwd();
         } else
@@ -207,14 +205,13 @@ public boolean dispatchKeyEvent(KeyEvent event) {
 
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
-        if(blockedKeys.contains(event.getKeyCode())){
+        if (blockedKeys.contains(event.getKeyCode())) {
             return true;
         }
         return super.onKeyDown(keyCode, event);
     }
 
-    private void askPassword()
-    {
+    private void askPassword() {
         dialogPrompted = true;
 
         dialog = new Dialog(webView.getContext());
@@ -235,6 +232,9 @@ public void onDismiss(DialogInterface dialogInterface) {
         b2 = dialog.findViewById(R.id.b2);
         b3 = dialog.findViewById(R.id.b3);
         b4 = dialog.findViewById(R.id.b4);
+        b5 = dialog.findViewById(R.id.b5);
+        b6 = dialog.findViewById(R.id.b6);
+
 
         n0 = dialog.findViewById(R.id.number0);
         n1 = dialog.findViewById(R.id.number1);
diff --git a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
index 3662295..e0ff1bd 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
@@ -2,29 +2,46 @@
 
 import android.app.Activity;
 import android.content.Context;
+import android.content.SharedPreferences;
+import android.graphics.Bitmap;
+import android.graphics.Color;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.view.View;
 import android.webkit.URLUtil;
 import android.widget.Button;
 import android.widget.EditText;
+import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import com.coderbunker.kioskapp.lib.Base32;
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.WriterException;
+import com.google.zxing.common.BitMatrix;
+import com.google.zxing.qrcode.QRCodeWriter;
+
 import static android.widget.Toast.LENGTH_LONG;
 
 public class SettingsActivity extends Activity {
 
     private Context context = this;
-    private EditText editPassword, editURL;
+    private EditText editURL;
     private Button saveChanges;
 
+    private ImageView imgQRCode;
+
+    private String otp_uri;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_settings);
 
-        editPassword = findViewById(R.id.editText_password);
+        SharedPreferences prefs = this.getSharedPreferences(
+                "com.coderbunker.kioskapp", Context.MODE_PRIVATE);
+
+        imgQRCode = findViewById(R.id.imgQRCode);
         editURL = findViewById(R.id.editText_URL);
 
         saveChanges = findViewById(R.id.button_save);
@@ -34,23 +51,61 @@ protected void onCreate(Bundle savedInstanceState) {
             public void onClick(View view) {
 
                 boolean changed = false;
-                String url =  editURL.getText().toString();
-                String password = editPassword.getText().toString();
+                String url = editURL.getText().toString();
 
-                if(url != "" &&  URLUtil.isValidUrl(url)) {
+                if (url != "" && URLUtil.isValidUrl(url)) {
                     KioskActivity.setURL(editURL.getText().toString());
                     changed = true;
                 }
-                if(password != "" && password.length()>0){
-                    KioskActivity.setPassword(editPassword.getText().toString());
-                    changed = true;
-                }
 
-               if(changed)
-                Toast.makeText(context, "Changes saved!", LENGTH_LONG).show();
+                if (changed)
+                    Toast.makeText(context, "Changes saved!", LENGTH_LONG).show();
 
-               finish();
+                finish();
             }
         });
+
+        String otp = prefs.getString("otp", null);
+        if (otp == null) {
+
+            byte key_1 = (byte) Math.floor(Math.random() * 10);
+            byte key_2 = (byte) Math.floor(Math.random() * 10);
+            byte key_3 = (byte) Math.floor(Math.random() * 10);
+            byte key_4 = (byte) Math.floor(Math.random() * 10);
+            byte key_5 = (byte) Math.floor(Math.random() * 10);
+            byte key_6 = (byte) Math.floor(Math.random() * 10);
+
+            byte[] key = {key_1, key_2, key_3, key_4, key_5, key_6, (byte) 0xDE, (byte) 0xAD, (byte) 0xBE, (byte) 0xEF};
+
+            otp = Base32.encode(key);
+
+            SharedPreferences.Editor editor = prefs.edit();
+
+            editor.putString("otp", otp);
+            editor.apply();
+        }
+
+        otp_uri = "otpauth://totp/Admin:coderbunker.com?secret=" + otp + "&issuer=Coderbunker";
+
+        generateQRCode(otp_uri);
+    }
+
+    private void generateQRCode(String uri) {
+        QRCodeWriter writer = new QRCodeWriter();
+        try {
+            BitMatrix bitMatrix = writer.encode(uri, BarcodeFormat.QR_CODE, 512, 512);
+            int width = bitMatrix.getWidth();
+            int height = bitMatrix.getHeight();
+            Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
+            for (int x = 0; x < width; x++) {
+                for (int y = 0; y < height; y++) {
+                    bmp.setPixel(x, y, bitMatrix.get(x, y) ? Color.BLACK : Color.WHITE);
+                }
+            }
+            imgQRCode.setImageBitmap(bmp);
+
+        } catch (WriterException e) {
+            e.printStackTrace();
+        }
     }
 }
diff --git a/app/src/main/java/com/coderbunker/kioskapp/lib/Base32.java b/app/src/main/java/com/coderbunker/kioskapp/lib/Base32.java
new file mode 100644
index 0000000..5dcf1e4
--- /dev/null
+++ b/app/src/main/java/com/coderbunker/kioskapp/lib/Base32.java
@@ -0,0 +1,176 @@
+/*
+ * Taken with small modifications
+ *
+ * Copyright 2009 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.coderbunker.kioskapp.lib;
+
+import java.security.SecureRandom;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Locale;
+
+/**
+ * Encodes arbitrary byte arrays as case-insensitive base-32 strings.
+ * <p>
+ * The implementation is slightly different than in RFC 4648. During encoding,
+ * padding is not added, and during decoding the last incomplete chunk is not
+ * taken into account. The result is that multiple strings decode to the same
+ * byte array, for example, string of sixteen 7s ("7...7") and seventeen 7s both
+ * decode to the same byte array.
+ * TODO(sarvar): Revisit this encoding and whether this ambiguity needs fixing.
+ *
+ * @author sweis@google.com (Steve Weis)
+ * @author Neal Gafter
+ */
+public class Base32 {
+    // singleton
+
+    private static final int SECRET_SIZE = 10;
+
+    private static final SecureRandom RANDOM = new SecureRandom();
+
+    private static final Base32 INSTANCE =
+            new Base32("ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"); // RFC 4648/3548
+
+    static Base32 getInstance() {
+        return INSTANCE;
+    }
+
+    // 32 alpha-numeric characters.
+    private String ALPHABET;
+    private char[] DIGITS;
+    private int MASK;
+    private int SHIFT;
+    private HashMap<Character, Integer> CHAR_MAP;
+
+    static final String SEPARATOR = "-";
+
+    protected Base32(String alphabet) {
+        this.ALPHABET = alphabet;
+        DIGITS = ALPHABET.toCharArray();
+        MASK = DIGITS.length - 1;
+        SHIFT = Integer.numberOfTrailingZeros(DIGITS.length);
+        CHAR_MAP = new HashMap<Character, Integer>();
+        for (int i = 0; i < DIGITS.length; i++) {
+            CHAR_MAP.put(DIGITS[i], i);
+        }
+    }
+
+    public static byte[] decode(String encoded) throws DecodingException {
+        return getInstance().decodeInternal(encoded);
+    }
+
+    protected byte[] decodeInternal(String encoded) throws DecodingException {
+        // Remove whitespace and separators
+        encoded = encoded.trim().replaceAll(SEPARATOR, "").replaceAll(" ", "");
+
+        // Remove padding. Note: the padding is used as hint to determine how many
+        // bits to decode from the last incomplete chunk (which is commented out
+        // below, so this may have been wrong to start with).
+        encoded = encoded.replaceFirst("[=]*$", "");
+
+        // Canonicalize to all upper case
+        encoded = encoded.toUpperCase(Locale.US);
+        if (encoded.length() == 0) {
+            return new byte[0];
+        }
+        int encodedLength = encoded.length();
+        int outLength = encodedLength * SHIFT / 8;
+        byte[] result = new byte[outLength];
+        int buffer = 0;
+        int next = 0;
+        int bitsLeft = 0;
+        for (char c : encoded.toCharArray()) {
+            if (!CHAR_MAP.containsKey(c)) {
+                throw new DecodingException("Illegal character: " + c);
+            }
+            buffer <<= SHIFT;
+            buffer |= CHAR_MAP.get(c) & MASK;
+            bitsLeft += SHIFT;
+            if (bitsLeft >= 8) {
+                result[next++] = (byte) (buffer >> (bitsLeft - 8));
+                bitsLeft -= 8;
+            }
+        }
+        // We'll ignore leftover bits for now.
+        //
+        // if (next != outLength || bitsLeft >= SHIFT) {
+        //  throw new DecodingException("Bits left: " + bitsLeft);
+        // }
+        return result;
+    }
+
+    public static String encode(byte[] data) {
+        return getInstance().encodeInternal(data);
+    }
+
+    protected String encodeInternal(byte[] data) {
+        if (data.length == 0) {
+            return "";
+        }
+
+        // SHIFT is the number of bits per output character, so the length of the
+        // output is the length of the input multiplied by 8/SHIFT, rounded up.
+        if (data.length >= (1 << 28)) {
+            // The computation below will fail, so don't do it.
+            throw new IllegalArgumentException();
+        }
+
+        int outputLength = (data.length * 8 + SHIFT - 1) / SHIFT;
+        StringBuilder result = new StringBuilder(outputLength);
+
+        int buffer = data[0];
+        int next = 1;
+        int bitsLeft = 8;
+        while (bitsLeft > 0 || next < data.length) {
+            if (bitsLeft < SHIFT) {
+                if (next < data.length) {
+                    buffer <<= 8;
+                    buffer |= (data[next++] & 0xff);
+                    bitsLeft += 8;
+                } else {
+                    int pad = SHIFT - bitsLeft;
+                    buffer <<= pad;
+                    bitsLeft += pad;
+                }
+            }
+            int index = MASK & (buffer >> (bitsLeft - SHIFT));
+            bitsLeft -= SHIFT;
+            result.append(DIGITS[index]);
+        }
+        return result.toString();
+    }
+
+    public static class DecodingException extends Exception {
+        public DecodingException(String message) {
+            super(message);
+        }
+    }
+
+    public static String random() {
+
+        // Allocating the buffer
+        byte[] buffer = new byte[SECRET_SIZE];
+
+        // Filling the buffer with random numbers.
+        RANDOM.nextBytes(buffer);
+
+        // Getting the key and converting it to Base32
+        byte[] secretKey = Arrays.copyOf(buffer, SECRET_SIZE);
+        return encode(secretKey);
+    }
+}
diff --git a/app/src/main/res/layout/activity_settings.xml b/app/src/main/res/layout/activity_settings.xml
index 2c9070d..807055f 100644
--- a/app/src/main/res/layout/activity_settings.xml
+++ b/app/src/main/res/layout/activity_settings.xml
@@ -14,22 +14,20 @@
 
 
         <TextView
-            android:id="@+id/textView_password"
+            android:id="@+id/textView_otp"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:textColor="@android:color/black"
-            android:textSize="22dp"
             android:gravity="center_horizontal"
             android:paddingVertical="20dp"
-            android:text="Password" />
+            android:text="OTP"
+            android:textColor="@android:color/black"
+            android:textSize="22dp" />
 
-        <EditText
-            android:id="@+id/editText_password"
+        <ImageView
+            android:id="@+id/imgQRCode"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:ems="10"
-            android:inputType="numberPassword"
-            android:hint="Enter the new password here..."/>
+            android:src="@drawable/ic_launcher_background" />
 
         <TextView
             android:id="@+id/textView_URL"
diff --git a/app/src/main/res/layout/password_dialog.xml b/app/src/main/res/layout/password_dialog.xml
index 8ee2ac6..2fb7155 100644
--- a/app/src/main/res/layout/password_dialog.xml
+++ b/app/src/main/res/layout/password_dialog.xml
@@ -45,6 +45,20 @@
             android:layout_weight="1"
             android:clickable="false" />
 
+        <Button
+            android:id="@+id/b5"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:clickable="false" />
+
+        <Button
+            android:id="@+id/b6"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:clickable="false" />
+
     </LinearLayout>
 
     <LinearLayout

From d3939b546a18135aed72ec9a2bf45f105aabc914 Mon Sep 17 00:00:00 2001
From: Julian Schmuckli <julian@schmuckli.net>
Date: Mon, 6 Aug 2018 11:25:41 +0800
Subject: [PATCH 2/5] Finished OTP implementation #5

---
 .idea/caches/build_file_checksums.ser         | Bin 536 -> 536 bytes
 app/build.gradle                              |   2 +-
 .../coderbunker/kioskapp/KioskActivity.java   |  24 ++++-
 .../coderbunker/kioskapp/MainActivity.java    |   4 +-
 .../kioskapp/SettingsActivity.java            |   2 +-
 .../com/coderbunker/kioskapp/lib/TOTP.java    |  88 ++++++++++++++++++
 6 files changed, 112 insertions(+), 8 deletions(-)
 create mode 100644 app/src/main/java/com/coderbunker/kioskapp/lib/TOTP.java

diff --git a/.idea/caches/build_file_checksums.ser b/.idea/caches/build_file_checksums.ser
index d9501ab451e0815b2578abb30cd2a41e69556a2e..595be42bb13139df3cd233f4b8f5cb8b61bcb44a 100644
GIT binary patch
delta 33
pcmbQiGJ|Epbe2?}zYH5^=P(NXU=_*m5a^Z>*Xm<S@Z52y0sz6k3!VS~

delta 33
rcmV++0N($Y1egSnmjq<}%2u(PYylDdDQ{WuL5<6wtfrJ?2tzD*{v8hf

diff --git a/app/build.gradle b/app/build.gradle
index e102807..48983f6 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -20,7 +20,7 @@ android {
 
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation 'com.android.support:appcompat-v7:27.0.0'
+    implementation 'com.android.support:appcompat-v7:27.1.1'
     implementation 'com.android.support.constraint:constraint-layout:1.1.2'
     implementation 'com.android.support:support-v4:27.1.1'
     implementation 'com.journeyapps:zxing-android-embedded:3.6.0'
diff --git a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
index 62ec944..c648be2 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
@@ -4,6 +4,7 @@
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
 import android.os.Bundle;
 import android.view.KeyEvent;
@@ -13,6 +14,9 @@
 import android.view.WindowManager;
 import android.webkit.WebView;
 import android.widget.Button;
+import android.widget.Toast;
+
+import com.coderbunker.kioskapp.lib.TOTP;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -43,6 +47,8 @@ public class KioskActivity extends Activity {
 
     private Timer timerLock, timerNav;
 
+    private SharedPreferences prefs;
+
     @Override
     public void onBackPressed() {
         //Do nothing...
@@ -87,6 +93,9 @@ public boolean onTouch(View view, MotionEvent motionEvent) {
             }
         });
 
+        prefs = this.getSharedPreferences(
+                "com.coderbunker.kioskapp", Context.MODE_PRIVATE);
+
         TimerTask lock = new TimerTask() {
             @Override
             public void run() {
@@ -180,13 +189,18 @@ public void enterNumber(String number) {
     }
 
     private void checkPwd() {
-        String pwd = b1.getText().toString() + b2.getText().toString() + b3.getText().toString() + b4.getText().toString();
-        if (password.equals(pwd)) {
-            finish();
+        String otp = prefs.getString("otp", null);
+        String pwd = b1.getText().toString() + b2.getText().toString() + b3.getText().toString() + b4.getText().toString() + b5.getText().toString() + b6.getText().toString();
+        String generated_number = TOTP.generateCurrentNumber(otp, System.currentTimeMillis());
+        String previous_generated_number = TOTP.generateCurrentNumber(otp, System.currentTimeMillis() - 30000);
 
+        if (pwd.equals(generated_number) || pwd.equals(previous_generated_number)) {
+            Toast.makeText(context, "PIN correct", Toast.LENGTH_SHORT).show();
+            finish();
         } else {
             dialog.dismiss();
             dialogPrompted = false;
+            Toast.makeText(context, "Wrong PIN", Toast.LENGTH_SHORT).show();
         }
 
         cptPwd = 0;
@@ -205,8 +219,10 @@ public boolean dispatchKeyEvent(KeyEvent event) {
 
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
+        Toast.makeText(context, "Clicked", Toast.LENGTH_SHORT).show();
         if (blockedKeys.contains(event.getKeyCode())) {
-            return true;
+            Toast.makeText(context, "Blocked", Toast.LENGTH_SHORT).show();
+            return false;
         }
         return super.onKeyDown(keyCode, event);
     }
diff --git a/app/src/main/java/com/coderbunker/kioskapp/MainActivity.java b/app/src/main/java/com/coderbunker/kioskapp/MainActivity.java
index cf0d938..7c28516 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/MainActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/MainActivity.java
@@ -16,8 +16,8 @@ protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
 
-        kioskmode = (Button) findViewById(R.id.button_kioskmode);
-        settings = (Button) findViewById(R.id.button_settings);
+        kioskmode = findViewById(R.id.button_kioskmode);
+        settings = findViewById(R.id.button_settings);
 
         kioskmode.setOnClickListener(new View.OnClickListener() {
             @Override
diff --git a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
index e0ff1bd..1b4d1b5 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
@@ -85,7 +85,7 @@ public void onClick(View view) {
             editor.apply();
         }
 
-        otp_uri = "otpauth://totp/Admin:coderbunker.com?secret=" + otp + "&issuer=Coderbunker";
+        otp_uri = "otpauth://totp/Admin?secret=" + otp + "&issuer=Coderbunker";
 
         generateQRCode(otp_uri);
     }
diff --git a/app/src/main/java/com/coderbunker/kioskapp/lib/TOTP.java b/app/src/main/java/com/coderbunker/kioskapp/lib/TOTP.java
new file mode 100644
index 0000000..5fa7b03
--- /dev/null
+++ b/app/src/main/java/com/coderbunker/kioskapp/lib/TOTP.java
@@ -0,0 +1,88 @@
+package com.coderbunker.kioskapp.lib;
+
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+public class TOTP {
+
+    private static int TIME_STEP_SECONDS = 30, NUM_DIGITS_OUTPUT = 6;
+
+    //Source: https://github.com/airG/java-totp/blob/master/src/main/java/com/j256/totp/TwoFactorAuthUtil.java
+
+    public static String generateCurrentNumber(String secret, long currentTimeMillis) {
+
+        byte[] key = new byte[0];
+        try {
+            key = Base32.decode(secret);
+        } catch (Base32.DecodingException e) {
+            e.printStackTrace();
+        }
+
+        byte[] data = new byte[8];
+        long value = currentTimeMillis / 1000 / TIME_STEP_SECONDS;
+        for (int i = 7; value > 0; i--) {
+            data[i] = (byte) (value & 0xFF);
+            value >>= 8;
+        }
+
+        // encrypt the data with the key and return the SHA1 of it in hex
+        SecretKeySpec signKey = new SecretKeySpec(key, "HmacSHA1");
+        // if this is expensive, could put in a thread-local
+        Mac mac = null;
+        try {
+            mac = Mac.getInstance("HmacSHA1");
+        } catch (NoSuchAlgorithmException e) {
+            e.printStackTrace();
+        }
+        try {
+            mac.init(signKey);
+        } catch (InvalidKeyException e) {
+            e.printStackTrace();
+        }
+        byte[] hash = mac.doFinal(data);
+
+        // take the 4 least significant bits from the encrypted string as an offset
+        int offset = hash[hash.length - 1] & 0xF;
+
+        // We're using a long because Java hasn't got unsigned int.
+        long truncatedHash = 0;
+        for (int i = offset; i < offset + 4; ++i) {
+            truncatedHash <<= 8;
+            // get the 4 bytes at the offset
+            truncatedHash |= (hash[i] & 0xFF);
+        }
+        // cut off the top bit
+        truncatedHash &= 0x7FFFFFFF;
+
+        // the token is then the last 6 digits in the number
+        truncatedHash %= 1000000;
+
+        return zeroPrepend(truncatedHash, NUM_DIGITS_OUTPUT);
+    }
+
+    private static String zeroPrepend(long num, int digits) {
+        String hashStr = Long.toString(num);
+        if (hashStr.length() >= digits) {
+            return hashStr;
+        } else {
+            StringBuilder sb = new StringBuilder(digits);
+            int zeroCount = digits - hashStr.length();
+            sb.append(blockOfZeros, 0, zeroCount);
+            sb.append(hashStr);
+            return sb.toString();
+        }
+    }
+
+    private static String blockOfZeros = null;
+
+    {
+        StringBuilder sb = new StringBuilder(NUM_DIGITS_OUTPUT);
+        for (int i = 0; i < NUM_DIGITS_OUTPUT; i++) {
+            sb.append('0');
+        }
+        blockOfZeros = sb.toString();
+    }
+}

From d741180d9bb767f94f83e55bbc87c40088a0319b Mon Sep 17 00:00:00 2001
From: Julian Schmuckli <julian@schmuckli.net>
Date: Mon, 6 Aug 2018 12:06:22 +0800
Subject: [PATCH 3/5] Implemented function to save URL in SharedPreferences

---
 app/src/main/AndroidManifest.xml              |  2 +-
 .../coderbunker/kioskapp/KioskActivity.java   | 10 +++---
 .../kioskapp/SettingsActivity.java            | 34 +++++++++----------
 app/src/main/res/layout/activity_settings.xml |  8 -----
 4 files changed, 23 insertions(+), 31 deletions(-)

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 6a0aa14..82f5607 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -28,7 +28,7 @@
             </intent-filter>
         </activity>
 
-        <activity android:name=".SettingsActivity"></activity>
+        <activity android:name=".SettingsActivity" />
     </application>
 
 </manifest>
\ No newline at end of file
diff --git a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
index c648be2..c5c440a 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
@@ -30,7 +30,7 @@ public class KioskActivity extends Activity {
     private final Context context = this;
     private WebView webView;
     private static String password = "1234";
-    private static String URL = "https://naibaben.github.io/";
+    private static String URL = "";
 
     private final List blockedKeys = new ArrayList(Arrays.asList(KeyEvent.KEYCODE_VOLUME_DOWN,
             KeyEvent.KEYCODE_VOLUME_UP, KeyEvent.KEYCODE_BACK, KeyEvent.KEYCODE_HOME, KeyEvent.KEYCODE_POWER, KeyEvent.KEYCODE_APP_SWITCH));
@@ -71,6 +71,11 @@ protected void onCreate(Bundle savedInstanceState) {
 
         setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
 
+        prefs = this.getSharedPreferences(
+                "com.coderbunker.kioskapp", Context.MODE_PRIVATE);
+
+        URL = prefs.getString("url", "https://naibaben.github.io/");
+
         //Get the webView and load the URL
         webView = findViewById(R.id.webview);
         webView.setWebViewClient(new KioskWebviewClient());
@@ -93,9 +98,6 @@ public boolean onTouch(View view, MotionEvent motionEvent) {
             }
         });
 
-        prefs = this.getSharedPreferences(
-                "com.coderbunker.kioskapp", Context.MODE_PRIVATE);
-
         TimerTask lock = new TimerTask() {
             @Override
             public void run() {
diff --git a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
index 1b4d1b5..a293250 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
@@ -7,6 +7,7 @@
 import android.graphics.Color;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.view.KeyEvent;
 import android.view.View;
 import android.webkit.URLUtil;
 import android.widget.Button;
@@ -27,7 +28,7 @@ public class SettingsActivity extends Activity {
 
     private Context context = this;
     private EditText editURL;
-    private Button saveChanges;
+    private SharedPreferences prefs;
 
     private ImageView imgQRCode;
 
@@ -38,34 +39,31 @@ protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_settings);
 
-        SharedPreferences prefs = this.getSharedPreferences(
+        prefs = this.getSharedPreferences(
                 "com.coderbunker.kioskapp", Context.MODE_PRIVATE);
 
         imgQRCode = findViewById(R.id.imgQRCode);
         editURL = findViewById(R.id.editText_URL);
 
-        saveChanges = findViewById(R.id.button_save);
-        saveChanges.setOnClickListener(new View.OnClickListener() {
 
-            @Override
-            public void onClick(View view) {
+        /* TODO Save after button press or change listener
 
-                boolean changed = false;
-                String url = editURL.getText().toString();
+        boolean changed = false;
+        String url = editURL.getText().toString();
 
-                if (url != "" && URLUtil.isValidUrl(url)) {
-                    KioskActivity.setURL(editURL.getText().toString());
-                    changed = true;
-                }
-
-                if (changed)
-                    Toast.makeText(context, "Changes saved!", LENGTH_LONG).show();
+        if (url != "" && URLUtil.isValidUrl(url)) {
+            prefs.edit().putString("url", url).apply();
+            changed = true;
+        }
 
-                finish();
-            }
-        });
+        if (changed)
+            Toast.makeText(context, "Changes saved!", LENGTH_LONG).show();*/
 
         String otp = prefs.getString("otp", null);
+        String url = prefs.getString("url", "https://naibaben.github.io/");
+
+        editURL.setText(url);
+
         if (otp == null) {
 
             byte key_1 = (byte) Math.floor(Math.random() * 10);
diff --git a/app/src/main/res/layout/activity_settings.xml b/app/src/main/res/layout/activity_settings.xml
index 807055f..0bb8176 100644
--- a/app/src/main/res/layout/activity_settings.xml
+++ b/app/src/main/res/layout/activity_settings.xml
@@ -46,14 +46,6 @@
             android:inputType="textUri"
             android:hint="Enter the URL here..."/>
 
-        <Button
-            android:id="@+id/button_save"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:layout_gravity="center_horizontal"
-            android:layout_marginTop="50dp"
-            android:text="Save changes" />
-
 
     </LinearLayout>
 

From 72cdea6e288b274a27125551c1d979af9297226b Mon Sep 17 00:00:00 2001
From: Julian Schmuckli <julian@schmuckli.net>
Date: Tue, 7 Aug 2018 16:12:51 +0800
Subject: [PATCH 4/5] Fixed bug with saving URL and implemented function to
 prevent home button click

---
 app/src/main/AndroidManifest.xml              | 14 +--
 .../coderbunker/kioskapp/KioskActivity.java   | 36 +++++---
 .../kioskapp/KioskWebviewClient.java          |  6 +-
 .../kioskapp/SettingsActivity.java            | 29 ++++---
 app/src/main/res/layout/activity_settings.xml | 86 +++++++++++--------
 5 files changed, 99 insertions(+), 72 deletions(-)

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 82f5607..3e66688 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -8,21 +8,21 @@
 
 
     <application
-        android:allowBackup="true"
+        android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
+        android:launchMode="singleTask"
         android:roundIcon="@mipmap/ic_launcher_round"
-        android:supportsRtl="true"
-        android:theme="@style/AppTheme">
+        android:stateNotNeeded="true"
+        android:supportsRtl="true">
         <activity android:name=".MainActivity">
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
 
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
         </activity>
         <activity android:name=".KioskActivity">
             <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
                 <category android:name="android.intent.category.HOME" />
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
diff --git a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
index c5c440a..2d79157 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/KioskActivity.java
@@ -4,6 +4,7 @@
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
+import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
 import android.os.Bundle;
@@ -81,6 +82,7 @@ protected void onCreate(Bundle savedInstanceState) {
         webView.setWebViewClient(new KioskWebviewClient());
         webView.getSettings().setJavaScriptEnabled(true);
         webView.loadUrl(URL);
+        Toast.makeText(this, "Loading " + URL, Toast.LENGTH_SHORT).show();
 
         webView.setOnTouchListener(new View.OnTouchListener() {
 
@@ -190,19 +192,31 @@ public void enterNumber(String number) {
 
     }
 
+    private void launchHome() {
+        Intent intent = new Intent(KioskActivity.this, MainActivity.class);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        startActivity(intent);
+        finish();
+    }
+
     private void checkPwd() {
         String otp = prefs.getString("otp", null);
-        String pwd = b1.getText().toString() + b2.getText().toString() + b3.getText().toString() + b4.getText().toString() + b5.getText().toString() + b6.getText().toString();
-        String generated_number = TOTP.generateCurrentNumber(otp, System.currentTimeMillis());
-        String previous_generated_number = TOTP.generateCurrentNumber(otp, System.currentTimeMillis() - 30000);
-
-        if (pwd.equals(generated_number) || pwd.equals(previous_generated_number)) {
-            Toast.makeText(context, "PIN correct", Toast.LENGTH_SHORT).show();
-            finish();
+        if (otp == null) {
+            Toast.makeText(context, "Please go to the settings and create a password", Toast.LENGTH_SHORT).show();
+            launchHome();
         } else {
-            dialog.dismiss();
-            dialogPrompted = false;
-            Toast.makeText(context, "Wrong PIN", Toast.LENGTH_SHORT).show();
+            String pwd = b1.getText().toString() + b2.getText().toString() + b3.getText().toString() + b4.getText().toString() + b5.getText().toString() + b6.getText().toString();
+            String generated_number = TOTP.generateCurrentNumber(otp, System.currentTimeMillis());
+            String previous_generated_number = TOTP.generateCurrentNumber(otp, System.currentTimeMillis() - 30000);
+
+            if (pwd.equals(generated_number) || pwd.equals(previous_generated_number)) {
+                Toast.makeText(context, "PIN correct", Toast.LENGTH_SHORT).show();
+                launchHome();
+            } else {
+                dialog.dismiss();
+                dialogPrompted = false;
+                Toast.makeText(context, "Wrong PIN", Toast.LENGTH_SHORT).show();
+            }
         }
 
         cptPwd = 0;
@@ -210,8 +224,6 @@ private void checkPwd() {
 
     @Override
     public boolean dispatchKeyEvent(KeyEvent event) {
-
-
         if (blockedKeys.contains(event.getKeyCode())) {
             return true;
         } else {
diff --git a/app/src/main/java/com/coderbunker/kioskapp/KioskWebviewClient.java b/app/src/main/java/com/coderbunker/kioskapp/KioskWebviewClient.java
index f2d8a70..c403bd1 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/KioskWebviewClient.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/KioskWebviewClient.java
@@ -4,15 +4,13 @@
 import android.webkit.SslErrorHandler;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
+import android.widget.Toast;
 
 class KioskWebviewClient extends WebViewClient {
 
-    private String URL = "https://naibaben.github.io/";
-
     @Override
     public boolean shouldOverrideUrlLoading(WebView view, String url) {
-
-        if(url.contains(url)) {
+        if (url.contains(url)) {
             view.loadUrl(url);
         }
         return true;
diff --git a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
index a293250..35eebb5 100644
--- a/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
+++ b/app/src/main/java/com/coderbunker/kioskapp/SettingsActivity.java
@@ -28,9 +28,10 @@ public class SettingsActivity extends Activity {
 
     private Context context = this;
     private EditText editURL;
-    private SharedPreferences prefs;
-
     private ImageView imgQRCode;
+    private Button btnSave;
+
+    private SharedPreferences prefs;
 
     private String otp_uri;
 
@@ -44,20 +45,24 @@ protected void onCreate(Bundle savedInstanceState) {
 
         imgQRCode = findViewById(R.id.imgQRCode);
         editURL = findViewById(R.id.editText_URL);
+        btnSave = findViewById(R.id.btnSave);
 
 
-        /* TODO Save after button press or change listener
+        btnSave.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                boolean changed = false;
+                String url = editURL.getText().toString();
 
-        boolean changed = false;
-        String url = editURL.getText().toString();
-
-        if (url != "" && URLUtil.isValidUrl(url)) {
-            prefs.edit().putString("url", url).apply();
-            changed = true;
-        }
+                if (url != "" && URLUtil.isValidUrl(url)) {
+                    prefs.edit().putString("url", url).apply();
+                    changed = true;
+                }
 
-        if (changed)
-            Toast.makeText(context, "Changes saved!", LENGTH_LONG).show();*/
+                if (changed)
+                    Toast.makeText(context, "Changes saved!", LENGTH_LONG).show();
+            }
+        });
 
         String otp = prefs.getString("otp", null);
         String url = prefs.getString("url", "https://naibaben.github.io/");
diff --git a/app/src/main/res/layout/activity_settings.xml b/app/src/main/res/layout/activity_settings.xml
index 0bb8176..becf23a 100644
--- a/app/src/main/res/layout/activity_settings.xml
+++ b/app/src/main/res/layout/activity_settings.xml
@@ -1,52 +1,64 @@
 <?xml version="1.0" encoding="utf-8"?>
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/root"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical"
     tools:context=".SettingsActivity">
 
-    <LinearLayout
+    <ScrollView
+        android:id="@+id/scrollView"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
-        android:orientation="vertical">
+        android:layout_height="match_parent">
 
-
-        <TextView
-            android:id="@+id/textView_otp"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:gravity="center_horizontal"
-            android:paddingVertical="20dp"
-            android:text="OTP"
-            android:textColor="@android:color/black"
-            android:textSize="22dp" />
-
-        <ImageView
-            android:id="@+id/imgQRCode"
+        <LinearLayout
             android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:src="@drawable/ic_launcher_background" />
+            android:layout_height="match_parent"
+            android:orientation="vertical">
 
-        <TextView
-            android:id="@+id/textView_URL"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:textColor="@android:color/black"
-            android:textSize="22dp"
-            android:gravity="center_horizontal"
-            android:paddingVertical="20dp"
-            android:text="URL" />
-
-        <EditText
-            android:id="@+id/editText_URL"
-            android:layout_width="match_parent"
-            android:layout_height="wrap_content"
-            android:inputType="textUri"
-            android:hint="Enter the URL here..."/>
 
+            <TextView
+                android:id="@+id/textView_otp"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:gravity="center_horizontal"
+                android:paddingVertical="20dp"
+                android:text="TOTP"
+                android:textColor="@android:color/black"
+                android:textSize="22dp" />
+
+            <ImageView
+                android:id="@+id/imgQRCode"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:src="@drawable/ic_launcher_background" />
+
+            <TextView
+                android:id="@+id/textView_URL"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:gravity="center_horizontal"
+                android:paddingVertical="20dp"
+                android:text="URL"
+                android:textColor="@android:color/black"
+                android:textSize="22dp" />
+
+            <EditText
+                android:id="@+id/editText_URL"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:hint="Enter the URL here..."
+                android:inputType="textUri" />
+
+            <Button
+                android:id="@+id/btnSave"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="Save" />
 
-    </LinearLayout>
 
-</LinearLayout>
\ No newline at end of file
+        </LinearLayout>
+    </ScrollView>
+</RelativeLayout>
\ No newline at end of file

From 26a7aa7eae8e02ba15282311714660cfddd7c0d7 Mon Sep 17 00:00:00 2001
From: Julian Schmuckli <julian@schmuckli.net>
Date: Tue, 7 Aug 2018 16:22:25 +0800
Subject: [PATCH 5/5] Set as default landscape mode

---
 app/src/main/AndroidManifest.xml | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 3e66688..e86234e 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -15,7 +15,9 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:stateNotNeeded="true"
         android:supportsRtl="true">
-        <activity android:name=".MainActivity">
+        <activity
+            android:name=".MainActivity"
+            android:screenOrientation="landscape">
 
         </activity>
         <activity android:name=".KioskActivity">
@@ -28,7 +30,9 @@
             </intent-filter>
         </activity>
 
-        <activity android:name=".SettingsActivity" />
+        <activity
+            android:name=".SettingsActivity"
+            android:screenOrientation="landscape" />
     </application>
 
 </manifest>
\ No newline at end of file