MLvZ4yzW

1package com.knowledgeflex.myencdycexo;
2
3import androidx.appcompat.app.AppCompatActivity;
4
5import android.os.Bundle;
6import android.util.Log;
7
8import java.io.File;
9import java.io.FileInputStream;
10import java.io.FileNotFoundException;
11import java.io.FileOutputStream;
12import java.io.IOException;
13import java.nio.charset.StandardCharsets;
14import java.security.InvalidAlgorithmParameterException;
15import java.security.InvalidKeyException;
16import java.security.NoSuchAlgorithmException;
17import java.security.SecureRandom;
18
19import javax.crypto.BadPaddingException;
20import javax.crypto.Cipher;
21import javax.crypto.IllegalBlockSizeException;
22import javax.crypto.KeyGenerator;
23import javax.crypto.NoSuchPaddingException;
24import javax.crypto.SecretKey;
25import javax.crypto.SecretKeyFactory;
26import javax.crypto.spec.IvParameterSpec;
27import javax.crypto.spec.SecretKeySpec;
28
29public class MainActivity extends AppCompatActivity {
30    private static Cipher cipher;
31    private int size;
32    private byte[] bytes;
33    private byte[] iv = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16};
34
35    @Override
36    protected void onCreate(Bundle savedInstanceState) {
37        super.onCreate(savedInstanceState);
38        setContentView(R.layout.activity_main);
39
40        try {
41            cipher = Cipher.getInstance("AES/CTR/NoPadding");
42        } catch (NoSuchAlgorithmException e) {
43            e.printStackTrace();
44        } catch (NoSuchPaddingException e) {
45            e.printStackTrace();
46        }
47
48        /*KeyGenerator keyGenerator = null;
49        try {
50            keyGenerator = KeyGenerator.getInstance("AES");
51        } catch (NoSuchAlgorithmException e) {
52            e.printStackTrace();
53        }
54
55        SecureRandom secureRandom = new SecureRandom();
56        int keyBitSize = 256;
57        keyGenerator.init(keyBitSize, secureRandom);
58
59        SecretKey secretKey = keyGenerator.generateKey(); */
60
61        SecretKeySpec key = new SecretKeySpec("abcdefghijklmnop".getBytes(StandardCharsets.UTF_8), "AES");
62
63        try {
64            try {
65                cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
66            } catch (InvalidAlgorithmParameterException e) {
67                e.printStackTrace();
68            }
69        } catch (InvalidKeyException e) {
70            e.printStackTrace();
71        }
72
73       // byte[] testBytes = "This is a test String".getBytes(StandardCharsets.UTF_8);
74
75       String path = getExternalFilesDir("enc_test").getAbsolutePath();
76
77        File file = new File(path, "encTextTest.mp4");
78
79        if (file.exists()) {
80            size = (int) file.length();
81            Log.v("MainActivity" , " File Size :  " + size);
82            bytes = new byte[size];
83
84        }
85            FileInputStream fileInputStream = null;
86            try {
87                fileInputStream = new FileInputStream(file);
88            } catch (FileNotFoundException e) {
89                e.printStackTrace();
90            }
91            try {
92                fileInputStream.read(bytes, 0, size - 1);
93            } catch (IOException e) {
94                e.printStackTrace();
95            }
96            try {
97                fileInputStream.close();
98            } catch (IOException e) {
99                e.printStackTrace();
100            }
101        File outputFile = new File(path, "decTextTest.mp4");
102
103
104        FileOutputStream fileOutputStream = null;
105        try {
106            fileOutputStream = new FileOutputStream(outputFile , false);
107        } catch (FileNotFoundException e) {
108            e.printStackTrace();
109        }
110            if(fileOutputStream != null) {
111                try {
112                    Log.v("MainActivity" , " Dec Started :  " + size);
113                    fileOutputStream.write(cipher.doFinal(bytes));
114                    fileOutputStream.flush();
115                    fileOutputStream.close();
116                    Log.v("MainActivity" , " Dec Done :  " + size);
117                } catch (IOException e) {
118                    e.printStackTrace();
119                } catch (BadPaddingException e) {
120                    e.printStackTrace();
121                } catch (IllegalBlockSizeException e) {
122                    e.printStackTrace();
123                }
124            }
125      /*  try {
126            bytes = cipher.doFinal(testBytes);
127            String normal = new String(testBytes, StandardCharsets.UTF_8);
128            String s = new String(bytes, StandardCharsets.UTF_8);
129            Log.v("MainActivity : ", "Normal : " + normal + "Encryption Succesful :  " + s );
130        } catch (BadPaddingException e) {
131            e.printStackTrace();
132        } catch (IllegalBlockSizeException e) {
133            e.printStackTrace();
134        } */
135
136     /*  Cipher cipher1 = null;
137        try {
138            cipher1 = Cipher.getInstance("AES/CTR/NoPadding");
139        } catch (NoSuchAlgorithmException e) {
140            e.printStackTrace();
141        } catch (NoSuchPaddingException e) {
142            e.printStackTrace();
143        }*/
144      /* try {
145            cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(iv));
146        } catch (InvalidKeyException e) {
147            e.printStackTrace();
148        } catch (InvalidAlgorithmParameterException e) {
149            e.printStackTrace();
150        }
151        try {
152            String s = new String(cipher.doFinal(bytes), StandardCharsets.UTF_8);
153            Log.v("MainActivity : ", "Decryption Succesful : " + s);
154        } catch (BadPaddingException e) {
155            e.printStackTrace();
156        } catch (IllegalBlockSizeException e) {
157            e.printStackTrace();
158        } */
159    }
160}