Android 对用户名密码进行加密操作存储在本地

比眉伴天荒 2022-08-22 03:52 229阅读 0赞

大家都知道当下大多数app都都有保存用户名密码的操作，仅仅将数据保存到SharedPreferences里面谁都能做的到，但是没有经过处理的数据直接以明文的形式存储，那么很容易就被坏人盗取，那么问题来了，如何对数据进行加密操作呢？  
这就要用到加密算法，加密有对称加密，非对称加密。较为常用的有DES,3DES,PBE,AES等  
下面我们所讲的就是其中的3DES  
3DES加密算法属于对称加密，即加密和解密所用的密钥是同一个key  
在进行3DES加密算法时要对加密算法最基础的Base64有一定的了解，因为Base64算法能对数据进行无损的编码  
key是Java虚拟机创建的临时对象，程序结束时会自动回收，因为加解密所用的key必须是一个key，所以我们需要使用ObjectOutputStream对key进行保存  
理清楚步骤：  
1.得到加解密所使用key  
2.对数据进行加密  
3.对key进行保存  
4.对加密后的数据进行保存  
5.对数据进行读取  
6.对key进行读取  
7.解密，得到解密后的正确数据

话不多说直接上代码

package wkk.demo4;
    
    import android.content.Context;
    import android.content.SharedPreferences;
    import android.os.Environment;
    import android.text.TextUtils;
    import android.util.Base64;
    import android.util.Log;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    
    import javax.crypto.Cipher;
    import javax.crypto.KeyGenerator;
    import javax.crypto.SecretKey;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.spec.DESedeKeySpec;
    
    /**
     * Created by wkk on 2016/5/11.
     */
    public class PasswordHelp {
        
    
        /**
         * 保存账号密码
         * @param context
         * @param number
         * @param password
         * @param isRemember 是否记住密码
         */
        public static void savePassword(Context context, String number, String password, boolean isRemember) {
            //对数据进行加密
            //得到key
            SecretKey key = PasswordHelp.readKey(PasswordHelp.getPath("a.a"));
            if (key == null) {
                key = get3DESKey();
                //保存key
                PasswordHelp.saveKey(key, PasswordHelp.getPath("a.a"));
            }
            //对得到number和password进行加密
            byte[] numberByte = encrypt3DES(number, key);
            byte[] passwordByte = encrypt3DES(password, key);
            number = Base64.encodeToString(numberByte, Base64.DEFAULT);
            password = Base64.encodeToString(passwordByte, Base64.DEFAULT);
    
            SharedPreferences sharedPreferences = context.getSharedPreferences("user", Context.MODE_PRIVATE);
            SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putString("number", number);
            editor.putString("password", password);
            editor.putBoolean("isRemember", isRemember);
            editor.commit();
        }
    
        //读取账号密码
        public static String[] readPassword(Context context) {
            SharedPreferences sharedPreferences = context.getSharedPreferences("user", Context.MODE_PRIVATE);
            String str[] = new String[]{sharedPreferences.getString("number", ""), sharedPreferences.getString("password", ""), String.valueOf(sharedPreferences.getBoolean("isRemember", false))};
            str[0] = d(str[0]);
            str[1] = d(str[1]);
            return str;
        }
    
        private static String d(String str) {
            if (!TextUtils.isEmpty(str)) {
                //对数据进行解密
                SecretKey key = readKey(PasswordHelp.getPath("a.a"));
                if (key != null) {
                    str = decoder3DES(Base64.decode(str.getBytes(), Base64.DEFAULT), key);
                }
            }
            return str;
        }
    
        //保存key
        public static boolean saveKey(SecretKey key, String path) {
            try {
                FileOutputStream fileOutputStream1 = new FileOutputStream(path);
                ObjectOutputStream objectOutputStream = new ObjectOutputStream(
                        fileOutputStream1);
                objectOutputStream.writeObject(key);
                objectOutputStream.flush();
                objectOutputStream.close();
                return true;
            } catch (Exception e) {
                Log.d("测试", e.toString());
            }
            return false;
        }
    
        //读取key
        public static SecretKey readKey(String path) {
            SecretKey key = null;
            try {
                ObjectInputStream objectInputStream = new ObjectInputStream(
                        new FileInputStream(path));
                key = (SecretKey) objectInputStream.readObject();
                objectInputStream.close();
            } catch (Exception e) {
                Log.d("测试:读取key:", e.toString());
            }
            return key;
        }
    
        //获取路径
        public static String getPath(String FileName) {
            if (TextUtils.isEmpty(FileName)) {
    
                return null;
            }
            File file = new File(Environment.getExternalStorageDirectory().getPath() + "/yhcm");
            if (!file.exists() || !file.isDirectory()) {
                file.mkdirs();
            }
    
            File file1 = new File(file, FileName);
            if (!file1.exists() || !file1.isFile()) {
                try {
                    file1.createNewFile();
                } catch (IOException e) {
                    Log.d("测试:文件创建失败：", e.toString());
                    return null;
                }
            }
            return file1.getPath();
        }
    
        /**
         * 数据加解密3DES所需要的Key
         */
        public static SecretKey get3DESKey() {
            try {
                // 生成key
                KeyGenerator keyGenerator = KeyGenerator.getInstance("DESede");
                keyGenerator.init(168);// can 168 or 112/new SecureRandom()
                SecretKey secretKey = keyGenerator.generateKey();
                byte[] bytesKey = secretKey.getEncoded();
    
                // 转化key
                DESedeKeySpec deSedeKeySpec = new DESedeKeySpec(bytesKey);
                SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
                SecretKey generateSecret = factory.generateSecret(deSedeKeySpec);
    
                return generateSecret;
            } catch (Exception e) {
                e.printStackTrace();
                Log.d("测试", e.toString());
            }
            return null;
        }
    
        /**
         * 数据加密3DES
         */
        private static byte[] encrypt3DES(String str, SecretKey generateSecret) {
            try {
                // 加密
                Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
                cipher.init(Cipher.ENCRYPT_MODE, generateSecret);
                byte[] result = cipher.doFinal(str.getBytes("utf-8"));
    
                return result;
            } catch (Exception e) {
                System.out.println("加密出错：" + e.getMessage());
            }
            return null;
        }
    
        /**
         * 数据解密3DES
         */
        private static String decoder3DES(byte[] str, SecretKey generateSecret) {
            try {
                // 加密
                Cipher cipher = Cipher.getInstance("DESede/ECB/PKCS5Padding");
                cipher.init(Cipher.DECRYPT_MODE, generateSecret);
                System.out.println(2);
                byte[] result = cipher.doFinal(str);
                System.out.println(3);
    
                return new String(result, "utf-8");
            } catch (Exception e) {
                System.out.println("解密出错:" + e.getMessage());
            }
            return null;
        }
    
    }

这个是我写的帮助类，可以调用savePassword和readPassword两个方法直接使用，当然建议修改下key文件存储的位置  
上面的一些功能也可以用在其他的很多地方，需要自己去灵活应用