From d506c71afa8aa1f41441f939eb7942d1d918049f Mon Sep 17 00:00:00 2001
From: Marcin Wozniak <marcinwozniak@zoho.com>
Date: Sat, 16 Nov 2019 23:21:46 +0100
Subject: [PATCH] Added en/de-cryption, fingerprint.

---
 .idea/misc.xml                                |   2 +-
 app/build.gradle                              |   7 +
 app/src/main/AndroidManifest.xml              |   1 +
 .../java/com/zadanie1/mw/FirstPassword.java   |  66 +++++--
 .../java/com/zadanie1/mw/FormPassword.java    |  68 +++++++-
 .../java/com/zadanie1/mw/MainActivity.java    | 165 ++++++++++++++----
 app/src/main/java/com/zadanie1/mw/Noto.java   | 134 +++++++++-----
 build.gradle                                  |   3 +-
 8 files changed, 352 insertions(+), 94 deletions(-)

diff --git a/.idea/misc.xml b/.idea/misc.xml
index dfd2c79..b6ea2b1 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" project-jdk-name="JDK" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="JDK" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/app/build.gradle b/app/build.gradle
index 75a4212..82d1544 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -16,13 +16,20 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
         }
     }
+    compileOptions {
+        sourceCompatibility = 1.8
+        targetCompatibility = 1.8
+    }
+    buildToolsVersion = '29.0.2'
 }
 
 dependencies {
+    implementation 'androidx.biometric:biometric:1.0.0'
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'androidx.appcompat:appcompat:1.0.2'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'androidx.test:runner:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
+
 }
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 9976b68..ab53633 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,6 +3,7 @@
     package="com.zadanie1.mw">
 
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-feature android:name="android.hardware.fingerprint" android:required="true" />
 
     <application
         android:allowBackup="true"
diff --git a/app/src/main/java/com/zadanie1/mw/FirstPassword.java b/app/src/main/java/com/zadanie1/mw/FirstPassword.java
index f3b1627..74c5ad4 100644
--- a/app/src/main/java/com/zadanie1/mw/FirstPassword.java
+++ b/app/src/main/java/com/zadanie1/mw/FirstPassword.java
@@ -1,21 +1,52 @@
 package com.zadanie1.mw;
 
-        import android.content.Intent;
-        import android.os.Bundle;
-        import android.app.Activity;
-        import android.view.View;
-        import android.widget.Button;
-        import android.widget.EditText;
-        import android.widget.TextView;
-        import android.widget.Toast;
+import android.content.Intent;
+import android.os.Bundle;
+import android.app.Activity;
+import android.view.View;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.TextView;
+import android.widget.Toast;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.math.BigInteger;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
-        import java.io.FileNotFoundException;
-        import java.io.FileOutputStream;
-        import java.io.IOException;
-        import java.io.PrintWriter;
 
 public class FirstPassword extends Activity {
     private static final String FILE_NAME = "passwd.txt";
+
+    public static String SHA512(String s)
+    {
+        MessageDigest digest;
+        String generatedPassword = null;
+        String salt = "cnsakn";
+        try
+        {
+            MessageDigest md = MessageDigest.getInstance("SHA-512");
+            md.update(salt.getBytes(StandardCharsets.UTF_8));
+
+            byte[] bytes = md.digest(s.getBytes(StandardCharsets.UTF_8));
+            StringBuilder sb = new StringBuilder();
+            for (int i = 0; i < bytes.length; i++) {
+                sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
+            }
+            generatedPassword = sb.toString();
+
+        }
+        catch (NoSuchAlgorithmException e)
+        {
+            e.printStackTrace();
+        }
+        return generatedPassword;
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -33,17 +64,16 @@ public class FirstPassword extends Activity {
             public void onClick(View arg0) {
                 if (newpassword.getText().toString().equals(renewpassword.getText().toString())) {
 
-                    String text = newpassword.getText().toString();
+                    String text = SHA512(newpassword.getText().toString());
                     FileOutputStream fos = null;
 
-                    Toast toast = Toast.makeText(getApplicationContext(),
-                            "Password has been changed",
-                            Toast.LENGTH_SHORT);
-                    toast.show();
-
                     try {
                         fos = openFileOutput(FILE_NAME, MODE_PRIVATE);
                         fos.write(text.getBytes());
+                        Toast toast = Toast.makeText(getApplicationContext(),
+                                "Password has been changed",
+                                Toast.LENGTH_SHORT);
+                        toast.show();
 
                     } catch (FileNotFoundException e) {
                         e.printStackTrace();
diff --git a/app/src/main/java/com/zadanie1/mw/FormPassword.java b/app/src/main/java/com/zadanie1/mw/FormPassword.java
index 29d0596..7d88c53 100644
--- a/app/src/main/java/com/zadanie1/mw/FormPassword.java
+++ b/app/src/main/java/com/zadanie1/mw/FormPassword.java
@@ -1,6 +1,7 @@
 package com.zadanie1.mw;
 
 import android.content.Intent;
+import android.os.Build;
 import android.os.Bundle;
 import android.app.Activity;
 import android.view.View;
@@ -9,15 +10,21 @@ import android.widget.EditText;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.RequiresApi;
+
 import java.io.File;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.FileReader;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 
 public class FormPassword extends Activity {
     private static final String FILE_NAME = "passwd.txt";
+    private static String input;
 
 
     public String readFile(String filename) throws IOException {
@@ -40,6 +47,56 @@ public class FormPassword extends Activity {
         return content;
     }
 
+    public static String SHA512(String s)
+    {
+        MessageDigest digest;
+        String generatedPassword = null;
+        String salt = "cnsakn";
+        try
+        {
+            MessageDigest md = MessageDigest.getInstance("SHA-512");
+            md.update(salt.getBytes(StandardCharsets.UTF_8));
+
+            byte[] bytes = md.digest(s.getBytes(StandardCharsets.UTF_8));
+            StringBuilder sb = new StringBuilder();
+            for (int i = 0; i < bytes.length; i++) {
+                sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
+            }
+            generatedPassword = sb.toString();
+
+        }
+        catch (NoSuchAlgorithmException e)
+        {
+            e.printStackTrace();
+        }
+        return generatedPassword;
+    }
+
+    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
+    private String unSHA512(String passwordToHash)
+    {
+        String generatedPassword = null;
+        String salt = "cnsakn";
+        try
+        {
+            MessageDigest md = MessageDigest.getInstance("SHA-512");
+            md.update(salt.getBytes(StandardCharsets.UTF_8));
+            byte[] bytes = md.digest(passwordToHash.getBytes(StandardCharsets.UTF_8));
+            StringBuilder sb = new StringBuilder();
+            for(int i=0; i< bytes.length ;i++)
+            {
+                sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
+            }
+            generatedPassword = sb.toString();
+        }
+        catch (NoSuchAlgorithmException e)
+        {
+            e.printStackTrace();
+        }
+        return generatedPassword;
+
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
 
@@ -61,11 +118,17 @@ public class FormPassword extends Activity {
                 final String filename =  getFilesDir() + "/passwd.txt";
                 File file = new File(filename);
 
+                input = currentpassword.getText().toString();
+                String SHAinput = unSHA512(input);
+                currentpassword.setText("");
+                String password = null;
+
                 try {
-                    if (currentpassword.getText().toString().equals(readFile(filename).toString())) {
+                    password = readFile(filename).toString();
+                    if(SHAinput.equals(password)){
                         if (newpassword.getText().toString().equals(renewpassword.getText().toString())) {
 
-                            String text = newpassword.getText().toString();
+                            String text = SHA512(newpassword.getText().toString());
                             FileOutputStream fos = null;
 
                             Toast toast = Toast.makeText(getApplicationContext(),
@@ -106,6 +169,7 @@ public class FormPassword extends Activity {
                 } catch (IOException e) {
                     e.printStackTrace();
                 }
+
                 currentpassword.getText().clear();
                 newpassword.getText().clear();
                 renewpassword.getText().clear();
diff --git a/app/src/main/java/com/zadanie1/mw/MainActivity.java b/app/src/main/java/com/zadanie1/mw/MainActivity.java
index 2434410..343c4b9 100644
--- a/app/src/main/java/com/zadanie1/mw/MainActivity.java
+++ b/app/src/main/java/com/zadanie1/mw/MainActivity.java
@@ -1,10 +1,12 @@
 package com.zadanie1.mw;
+import androidx.annotation.NonNull;
+import androidx.annotation.RequiresApi;
 import androidx.appcompat.app.AppCompatActivity;
-
-import android.Manifest;
+import androidx.biometric.BiometricPrompt;
 import android.content.Intent;
+import android.os.Build;
 import android.os.Bundle;
-import android.os.Environment;
+import android.os.Handler;
 import android.view.View;
 import android.widget.Button;
 import android.view.View.OnClickListener;
@@ -15,6 +17,10 @@ import android.widget.Toast;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.concurrent.Executor;
 
 
 public class MainActivity extends AppCompatActivity {
@@ -24,6 +30,7 @@ public class MainActivity extends AppCompatActivity {
     private EditText textPassword;
     private View viewPassword;
     private static final String filename = "passwd.txt";
+    private static String input;
 
     public String readFile(String filename) throws IOException {
         String content = null;
@@ -50,6 +57,42 @@ public class MainActivity extends AppCompatActivity {
 
     }
 
+    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
+    private String unSHA512(String passwordToHash)
+    {
+        String generatedPassword = null;
+        String salt = "cnsakn";
+        try
+        {
+            MessageDigest md = MessageDigest.getInstance("SHA-512");
+            md.update(salt.getBytes(StandardCharsets.UTF_8));
+            byte[] bytes = md.digest(passwordToHash.getBytes(StandardCharsets.UTF_8));
+            StringBuilder sb = new StringBuilder();
+            for(int i=0; i< bytes.length ;i++)
+            {
+                sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
+            }
+            generatedPassword = sb.toString();
+        }
+        catch (NoSuchAlgorithmException e)
+        {
+            e.printStackTrace();
+        }
+        return generatedPassword;
+
+    }
+
+
+    private Handler handler = new Handler();
+
+    private Executor executor = new Executor() {
+        @Override
+        public void execute(Runnable command) {
+            handler.post(command);
+        }
+    };
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -63,13 +106,15 @@ public class MainActivity extends AppCompatActivity {
                     FirstPassword.class);
             startActivity(myIntent3);
         }
+        else { showBiometricPrompt();
+        }
+
 
         response = (TextView) findViewById(R.id.textView);
         button = (Button) findViewById(R.id.button);
         restartpassword = (Button) findViewById(R.id.restartpassword);
         textPassword = findViewById(R.id.editText);
 
-
         restartpassword.setOnClickListener(new OnClickListener() {
             public void onClick(View arg0) {
                 Intent myIntent = new Intent(MainActivity.this,
@@ -83,39 +128,99 @@ public class MainActivity extends AppCompatActivity {
 
             @Override
             public void onClick(View view) {
-                /*response.setText(textPassword.getText());*/
-
                 File file = new File(filename);
 
-                 try {
-                     if (isFileExists(file)) {
-                         if (textPassword.getText().toString().equals(readFile(filename).toString())) {
-                             Toast toast = Toast.makeText(getApplicationContext(),
-                                     "Password is correct!",
-                                     Toast.LENGTH_SHORT);
-                             toast.show();
-                             Intent myIntent2 = new Intent(MainActivity.this,
-                                     Noto.class);
-                             startActivity(myIntent2);
+                try {
+                    input = textPassword.getText().toString();
+                    String SHAinput = unSHA512(input);
+                    textPassword.setText("");
+                    String password = readFile(filename).toString();
 
-                         } else {
-                             Toast toast = Toast.makeText(getApplicationContext(),
-                                     "Password is NOT correct",
-                                     Toast.LENGTH_SHORT);
-                             toast.show();
-                            }
-                     } else {
-                         Intent myIntent3 = new Intent(MainActivity.this,
-                                 FirstPassword.class);
-                         startActivity(myIntent3);
-                     }
+                    if (isFileExists(file)) {
 
-                 }  catch(IOException e){
-                     e.printStackTrace();
-                 }
+                        if(SHAinput.equals(password)){
+                            Toast toast = Toast.makeText(getApplicationContext(),
+                                    "Password is correct!",
+                                    Toast.LENGTH_SHORT);
+                            toast.show();
+                            Intent myIntent2 = new Intent(MainActivity.this,
+                                    Noto.class);
+                            startActivity(myIntent2);
+
+                        } else {
+                            Toast toast = Toast.makeText(getApplicationContext(),
+                                    "Password is NOT correct",
+                                    Toast.LENGTH_SHORT);
+                            toast.show();
+                        }
+                    } else {
+                        Intent myIntent3 = new Intent(MainActivity.this,
+                                FirstPassword.class);
+                        startActivity(myIntent3);
+                    }
+
+                }  catch(IOException e){
+                    e.printStackTrace();
+                }
                 textPassword.getText().clear();
             }
         });
 
     }
+    public static String getInput() {
+        return input;
+    }
+
+
+    private void showBiometricPrompt() {
+        BiometricPrompt.PromptInfo promptInfo =
+                new BiometricPrompt.PromptInfo.Builder()
+                .setTitle("Biometric login for my app")
+                .setSubtitle("Log in using your biometric credential")
+                .setNegativeButtonText("Cancel")
+                .build();
+
+        BiometricPrompt biometricPrompt = new BiometricPrompt(MainActivity.this,
+                executor, new BiometricPrompt.AuthenticationCallback() {
+            @Override
+            public void onAuthenticationError(int errorCode,
+                                              @NonNull CharSequence errString) {
+                super.onAuthenticationError(errorCode, errString);
+                Toast.makeText(getApplicationContext(),
+                        "Authentication error: " + errString, Toast.LENGTH_SHORT)
+                        .show();
+            }
+
+            @Override
+            public void onAuthenticationSucceeded(
+                    @NonNull BiometricPrompt.AuthenticationResult result) {
+                super.onAuthenticationSucceeded(result);
+                BiometricPrompt.CryptoObject authenticatedCryptoObject =
+                        result.getCryptoObject();
+                // User has verified the signature, cipher, or message
+                // authentication code (MAC) associated with the crypto object,
+                // so you can use it in your app's crypto-driven workflows.
+            }
+
+            @Override
+            public void onAuthenticationFailed() {
+                super.onAuthenticationFailed();
+                Toast.makeText(getApplicationContext(), "Authentication failed",
+                        Toast.LENGTH_SHORT)
+                        .show();
+                try {
+                    Thread.sleep(1000);
+                    System.exit(1);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+
+            }
+        });
+
+        // Displays the "log in" prompt.
+        biometricPrompt.authenticate(promptInfo);
+    }
+
+
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/zadanie1/mw/Noto.java b/app/src/main/java/com/zadanie1/mw/Noto.java
index e631f25..747fc6d 100644
--- a/app/src/main/java/com/zadanie1/mw/Noto.java
+++ b/app/src/main/java/com/zadanie1/mw/Noto.java
@@ -1,29 +1,48 @@
 package com.zadanie1.mw;
 
 import androidx.appcompat.app.AppCompatActivity;
-import android.app.Activity;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
-import android.widget.TextView;
 import android.widget.Toast;
-
-import java.io.BufferedInputStream;
 import java.io.BufferedReader;
+import java.io.DataInputStream;
+import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.io.UnsupportedEncodingException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.CipherOutputStream;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
 
 public class Noto extends AppCompatActivity {
     EditText ChangeNote;
     Button SaveNote;
-
     private static final String FILE_NAME = "notes.txt";
 
+    static String text;
+    private EditText textInputNotes;
+    private static String keyMultiply;
+    private static String key;
+    private static String initVector;
+    protected static String password;
+    protected static String soil= "yWaDPPsFMXxXwEJsTcf42";
+    int pom=0;
+
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -31,58 +50,91 @@ public class Noto extends AppCompatActivity {
 
         ChangeNote = (EditText) findViewById(R.id.changeNote);
         SaveNote = (Button) findViewById(R.id.SaveNote);
-                FileInputStream fis = null;
+        FileInputStream fis = null;
+        password = MainActivity.getInput();
 
-                try {
-                    fis = openFileInput(FILE_NAME);
-                    InputStreamReader isr = new InputStreamReader(fis);
-                    BufferedReader br = new BufferedReader(isr);
-                    StringBuffer sb = new StringBuffer();
-                    String text;
+        try {
+            FileInputStream fileInputStream = null;
+            File file = new File(getFilesDir() + "/" + FILE_NAME);
+            byte[] ciphertext = new byte[(int) file.length()];
+            fileInputStream = new FileInputStream(file);
+            fileInputStream.read(ciphertext);
 
-                    while ((text = br.readLine()) != null) {
-                        sb.append(text).append("\n");
-                    }
+            ChangeNote.setText(ciphertext.toString());
 
-                    if (sb.toString() != null) {
-                        ChangeNote.setText(sb.toString());
-                    }
-                } catch (FileNotFoundException e) {
-                    e.printStackTrace();
-                } catch (IOException e) {
-                    e.printStackTrace();
-                } finally {
-                    if (fis != null){
-                        try {
-                            fis.close();
-                        } catch (IOException e) {
-                            e.printStackTrace();
-                        }
-                    }
-                }
+            keyMultiply = password + soil + password + soil + soil + password + soil;
+            key = keyMultiply.substring(4, 20);
+            initVector = keyMultiply.substring(7, 23);
+
+            byte[] bytesKey = key.getBytes("UTF-8");
+            byte[] bytesIV = initVector.getBytes("UTF-8");
+            IvParameterSpec iv = new IvParameterSpec(bytesIV);
+            SecretKeySpec sKeySpec = new SecretKeySpec(bytesKey, "AES");
+
+            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
+            cipher.init(Cipher.DECRYPT_MODE, sKeySpec, iv);
+            String plaintext = new String(cipher.doFinal(ciphertext), "UTF-8");
+            ChangeNote.setText(plaintext);
+
+
+        } catch (NoSuchAlgorithmException e) {
+            e.printStackTrace();
+        } catch (BadPaddingException e) {
+            e.printStackTrace();
+        } catch (InvalidKeyException e) {
+            e.printStackTrace();
+        } catch (InvalidAlgorithmParameterException e) {
+            e.printStackTrace();
+        } catch (NoSuchPaddingException e) {
+            e.printStackTrace();
+        } catch (IllegalBlockSizeException e) {
+            e.printStackTrace();
+        } catch (UnsupportedEncodingException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 
 
     public void save (View v) throws IOException {
 
+        try {
         String text = ChangeNote.getText().toString();
         FileOutputStream fos = null;
 
-        try {
-            fos = openFileOutput(FILE_NAME, MODE_PRIVATE);
-            fos.write(text.getBytes());
+        keyMultiply = password + soil + password + soil + soil + password + soil;
+        key = keyMultiply.substring(4, 20);
+        initVector = keyMultiply.substring(7, 23);
+        IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
+        SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
 
-            /*ChangeNote.getText().clear();*/
-            Toast.makeText(this, "Saved to " + getFilesDir() + "/" + FILE_NAME, Toast.LENGTH_LONG).show();
+        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding");
+        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);
+
+        byte[] encrypted = cipher.doFinal(text.getBytes());
+
+        fos = openFileOutput(FILE_NAME, MODE_PRIVATE);
+        fos.write(encrypted);
+
+        Toast.makeText(this, "Saved to " + getFilesDir() + "/" + FILE_NAME, Toast.LENGTH_LONG).show();
 
         } catch (FileNotFoundException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
-        } finally {
-            if (fos != null){
-                fos.close();
-            }
+        } catch (NoSuchAlgorithmException e) {
+            e.printStackTrace();
+        } catch (InvalidKeyException e) {
+            e.printStackTrace();
+        } catch (InvalidAlgorithmParameterException e) {
+            e.printStackTrace();
+        } catch (NoSuchPaddingException e) {
+            e.printStackTrace();
+        } catch (BadPaddingException e) {
+            e.printStackTrace();
+        } catch (IllegalBlockSizeException e) {
+            e.printStackTrace();
         }
     }
 }
diff --git a/build.gradle b/build.gradle
index 48947c3..82defb3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -7,8 +7,7 @@ buildscript {
         
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.1'
-        
+        classpath 'com.android.tools.build:gradle:3.5.2'
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }