SQLite Data Base decryption using AES

Question

I'm trying to encrypt my data base and save it to sdCard using the answer of this post . But the problem is when I put back the file in the databases folder in my app package, it can't be read by SQLiteOpenHelper. the error :

08-30 10:58:35.692: E/SQLiteLog(3801): (26) file is encrypted or is not a database

08-30 10:58:35.692: E/DefaultDatabaseErrorHandler(3801): Corruption reported by sqlite on database: /data/data/com.padra_tech.karamad/databases/PrimaryInformation

08-30 10:58:35.692: E/DefaultDatabaseErrorHandler(3801): !@ make .back file

and this is my class :

package dataBases;


public class BackupHelper {

public static int SECURITY_NONE = 1 ;
public static int SECURITY_ENCRYPTED = 2 ;

public static void backup(Context context, int securityMode) {
    
    File backup = new File(Environment.getExternalStorageDirectory()+ 
            "/" + "KarAmad" + "/" + "backup");
    backup.mkdirs();
    
    List<File> src = new ArrayList<File>();
    List<File> dst = new ArrayList<File>();
    
    
    try {
        src.add( new File(new PrimaryInformationDataBase(context).getDirectory()) );
        dst.add( new File(backup.getPath() + "/" + "PI") );
        
        src.add( new File(new TransactionDataBase(context).getDirectory()) );
        dst.add( new File(backup.getPath() + "/" + "T") );
        
        src.add( new File(new NoteDataBase(context).getDirectory()) );
        dst.add( new File(backup.getPath() + "/" + "N") );
        
        src.add( new File(new PictureDataBase(context).getDirectory()) );
        dst.add( new File(backup.getPath() + "/" + "P") );
        
        for(int i = 0 ; i < src.size() ; i ++) {
            dst.get(i).createNewFile();
            if(securityMode == SECURITY_ENCRYPTED)
                BackupHelper.encrypt(src.get(i), dst.get(i));
            else
                LeftFragment.copy(src.get(i), dst.get(i));
        }
        
        Toast.makeText(context, "پشتیبان گیری انجام شد", Toast.LENGTH_SHORT).show();
        
    } catch (Exception e) {
        
        Toast.makeText(context, "پشتیبان گیری انجام نشد!", Toast.LENGTH_SHORT).show();
        e.printStackTrace();

    }
}

public static void restore(Context context, int securityMode) {
    
    NoteDataBase dummyNoteDataBase = new NoteDataBase(context);
    String temp = dummyNoteDataBase.getDirectory();
    String dataBasesPath = temp.substring(0, temp.lastIndexOf("/"));
    
    File source = new File(Environment.getExternalStorageDirectory()+ 
            "/" + "KarAmad" + "/" + "backup");
    
    List<File> src = new ArrayList<File>();
    List<File> dst = new ArrayList<File>();
    
    try {
        src.add( new File(source.getPath() + "/" + "PI") );
        dst.add( new File(dataBasesPath + "/" + "PrimaryInformation") );
        
        src.add( new File(source.getPath() + "/" + "T") );
        dst.add( new File(dataBasesPath + "/" + "Transaction") );
        
        src.add( new File(source.getPath() + "/" + "N") );
        dst.add( new File(dataBasesPath + "/" + "Note") );
        
        src.add( new File(source.getPath() + "/" + "P") );
        dst.add( new File(dataBasesPath + "/" + "Picture") );
        
        for(int i = 0 ; i < src.size() ; i++) {
            
            dst.get(i).createNewFile();
            
            if(securityMode == SECURITY_ENCRYPTED)
                BackupHelper.decrypt(src.get(i), dst.get(i));
            else
                LeftFragment.copy(src.get(i), dst.get(i));
        }
        
        
        
        Toast.makeText(context, "بازیابی فایل پشتیبان انجام شد", Toast.LENGTH_SHORT).show();
        
    } catch (Exception e) {
        
        Toast.makeText(context, "بازیابی فایل پشتیبان انجام نشد!", Toast.LENGTH_SHORT).show();
        e.printStackTrace();

    }
}

public static void encrypt(File src, File dst) throws IOException,
    NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
    
    FileInputStream inputStream = new FileInputStream(src);
    FileOutputStream outputStream = new FileOutputStream(dst);
    
    SecretKeySpec keySpec = new SecretKeySpec("1393032613930326".getBytes(), "AES");
    
    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.ENCRYPT_MODE, keySpec);
    
    CipherOutputStream cipherOutputStream = 
            new CipherOutputStream(outputStream, cipher);
    
    int b;
    byte[] d = new byte[8];
    while((b = inputStream.read(d)) > 0) {
        cipherOutputStream.write(d, 0, b);
    }
    
    cipherOutputStream.flush();
    cipherOutputStream.close();
    inputStream.close();
}


public static void decrypt(File src, File dst) throws IOException,
NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {

    FileInputStream inputStream = new FileInputStream(src);
    FileOutputStream outputStream = new FileOutputStream(dst);

    SecretKeySpec keySpec = new SecretKeySpec("1393032613930326".getBytes(), "AES");

    Cipher cipher = Cipher.getInstance("AES");
    cipher.init(Cipher.DECRYPT_MODE, keySpec);

    CipherInputStream cipherOutputStream = 
            new CipherInputStream(inputStream, cipher);

    int b;
    byte[] d = new byte[8];
    while((b = inputStream.read(d)) > 0) {
        outputStream.write(d, 0, b);
    }

    outputStream.flush();
    outputStream.close();
    cipherOutputStream.close();

}
}

Are you using the same code as the post? If not can you provide the code snippets that you use to Encrypt and Decrypt the database — hoomi, Aug 30 '14 at 07:18
I am just wondering. Are you trying to Encrypt the directory or the file? — hoomi, Aug 30 '14 at 07:33

score 2 · Accepted Answer · answered Aug 30 '14 at 07:35

2

The decrypt method reads from inputStream instead of the misnamed cipherOutputStream. So you are making just a copy instead of decrypting the DB.

answered Aug 30 '14 at 07:35

Henry

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score 0 · Answer 2 · answered Aug 30 '14 at 07:56

For Encrypting sql database in android please kindly use SQLCipher open library,
follow this simple steps to change existing database to  CipherDB.

Download the library and extract the files in to lib folder of your project. https://s3.amazonaws.com/sqlcipher/SQLCipher+for+Android+v3.1.0.zip

enter image description here

Change

import android.database.sqlite.SQLiteDatabase;
```
                  To
```
import net.sqlcipher.database.SQLiteDatabase;
Change

OpenHelper cipherHelper = new OpenHelper(Context); SQLiteHelper.sdb = cipherHelper.getWritableDatabase();
```
                  To
```
OpenHelper cipherHelper = new OpenHelper(Context); SQLiteHelper.sdb = cipherHelper.getWritableDatabase(encryptionPassword);

Note:Please uninstall the old application before run.

Source Link: https://www.zetetic.net/sqlcipher/sqlcipher-for-android/

SQLite Data Base decryption using AES

2 Answers2