如何在android中加密和解密我的应用程序数据库

My problem is that how to secure my application database file using encryption algorithm if i use hardcoded key then after decompiling it will be also accessible.if device is rooted then anyone can access my db file so i want to secure my db that is not accessible or readable by anyone. thanks in advance

我的问题是如何使用加密算法保护我的应用程序数据库文件如果我使用硬编码密钥然后反编译它也将是可访问的。如果设备已植根然后任何人都可以访问我的数据库文件所以我想保护我的无法访问的数据库或任何人都可读。提前致谢

2 个解决方案

#1

    package com.kushal.utils;

    import java.security.spec.KeySpec;
    import javax.crypto.Cipher;
    import javax.crypto.SecretKey;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.spec.DESedeKeySpec;
    import sun.misc.BASE64Decoder;
    import sun.misc.BASE64Encoder;

    public class DESedeEncryption {

        private static final String UNICODE_FORMAT = "UTF8";
        public static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
        private KeySpec myKeySpec;
        private SecretKeyFactory mySecretKeyFactory;
        private Cipher cipher;
        byte[] keyAsBytes;
        private String myEncryptionKey;
        private String myEncryptionScheme;
        SecretKey key;

        public DESedeEncryption() throws Exception
        {
            myEncryptionKey = "ThisIsSecretEncryptionKey";
            myEncryptionScheme = DESEDE_ENCRYPTION_SCHEME;
            keyAsBytes = myEncryptionKey.getBytes(UNICODE_FORMAT);
            myKeySpec = new DESedeKeySpec(keyAsBytes);
            mySecretKeyFactory = SecretKeyFactory.getInstance(myEncryptionScheme);
            cipher = Cipher.getInstance(myEncryptionScheme);
            key = mySecretKeyFactory.generateSecret(myKeySpec);
        }

        /**
         * Method To Encrypt The String
         */
        public String encrypt(String unencryptedString) {
            String encryptedString = null;
            try {
                cipher.init(Cipher.ENCRYPT_MODE, key);
                byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
                byte[] encryptedText = cipher.doFinal(plainText);
                BASE64Encoder base64encoder = new BASE64Encoder();
                encryptedString = base64encoder.encode(encryptedText);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return encryptedString;
        }
        /**
         * Method To Decrypt An Ecrypted String
         */
        public String decrypt(String encryptedString) {
            String decryptedText=null;
            try {
                cipher.init(Cipher.DECRYPT_MODE, key);
                BASE64Decoder base64decoder = new BASE64Decoder();
                byte[] encryptedText = base64decoder.decodeBuffer(encryptedString);
                byte[] plainText = cipher.doFinal(encryptedText);
                decryptedText= bytes2String(plainText);
            } catch (Exception e) {
                e.printStackTrace();
            }
            return decryptedText;
        }
        /**
         * Returns String From An Array Of Bytes
         */
        private static String bytes2String(byte[] bytes) {
            StringBuffer stringBuffer = new StringBuffer();
            for (int i = 0; i < bytes.length; i++) {
                stringBuffer.append((char) bytes[i]);
            }
            return stringBuffer.toString();
        }

        /**
         * Testing The DESede Encryption And Decryption Technique
         */
        public static void main(String args []) throws Exception
        {
            DESedeEncryption myEncryptor= new DESedeEncryption();

            String stringToEncrypt="Sanjaal.com";
            String encrypted=myEncryptor.encrypt(stringToEncrypt);
            String decrypted=myEncryptor.decrypt(encrypted);

            System.out.println("String To Encrypt: "+stringToEncrypt);
            System.out.println("Encrypted Value :" + encrypted);
            System.out.println("Decrypted Value :"+decrypted);

        }

    }

output:
String To Encrypt: Sanjaal.com
Encrypted Value :aArhqI25Y1SkYrdv9gxYDQ==
Decrypted Value :Sanjaal.com

http://sanjaal.com/java/189/java-encryption/tutorial-encryption-and-decryption-using-desede-triple-des-in-java/

#2

Use sqlite cipher to encrypt your database. and store your key in parts.and generate your key at runtime. you can not prevent anyone from de-compiling your application. all you can do is to make it too difficult for the de-compiler to understand your algo. you can try obfuscation on your application.

使用sqlite密码加密数据库。并将您的密钥存储在parts中。并在运行时生成密钥。你不能阻止任何人去编译你的申请。你所能做的就是让反编译器很难理解你的算法。你可以尝试在你的应用程序上进行模糊处理。

use dexGuard to encrypt Strings of your application.

使用dexGuard加密应用程序的字符串。