Android 自定义加密SharedPreferences

在项目开发中涉及到用户敏感信息在本地的储存问题，而SharedPreference是以明文的形式写在本地，非常不安全，要进行相应的加密。
正好有网上有dalao已经做好了轮子，非常Thanks♪(･ω･)ﾉ。我在dalao的基础上增加了一个静态方法来删除存储的内容来贴合目前的项目，具体的使用方法可以参考原文，由于是继承自SharedPreference，如果懂SharedPreference怎么用的话非常好上手。
【Android安全】自带加密光环的SharedPreference - CSDN博客 http://blog.csdn.net/voidmain_123/article/details/53338393

import android.annotation.TargetApi;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Build;
import android.preference.PreferenceManager;
import android.support.annotation.Nullable;
import android.text.TextUtils;
import android.util.Log;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * 自动加密SharedPreference
 */

public class SecuritySharedPreference implements SharedPreferences {

    private SharedPreferences mSharedPreferences;
    private static final String TAG = SecuritySharedPreference.class.getName();
    private Context mContext;

    //清空存储的内容
    public static void clear(Context context,String name) {
        SecuritySharedPreference preferences = new SecuritySharedPreference(context, name, Context.MODE_PRIVATE);
        SecuritySharedPreference.Editor editor = preferences.edit();
        editor.clear();
        editor.commit();
    }

    /**
     * constructor
     * @param context should be ApplicationContext not activity
     * @param name file name
     * @param mode context mode
     */
    public SecuritySharedPreference(Context context, String name, int mode){
        mContext = context;
        if (TextUtils.isEmpty(name)){
            mSharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
        } else {
            mSharedPreferences =  context.getSharedPreferences(name, mode);
        }

    }

    @Override
    public Map<String, String> getAll() {
        final Map<String, ?> encryptMap = mSharedPreferences.getAll();
        final Map<String, String> decryptMap = new HashMap<>();
        for (Map.Entry<String, ?> entry : encryptMap.entrySet()){
            Object cipherText = entry.getValue();
            if (cipherText != null){
                decryptMap.put(entry.getKey(), entry.getValue().toString());
            }
        }
        return decryptMap;
    }

    /**
     * encrypt function
     * @return cipherText base64
     */
    private String encryptPreference(String plainText){
        return EncryptUtil.getInstance(mContext).encrypt(plainText);
    }

    /**
     * decrypt function
     * @return plainText
     */
    private String decryptPreference(String cipherText){
        return EncryptUtil.getInstance(mContext).decrypt(cipherText);
    }

    @Nullable
    @Override
    public String getString(String key, String defValue) {
        final String encryptValue = mSharedPreferences.getString(encryptPreference(key), null);
        return encryptValue == null ? defValue : decryptPreference(encryptValue);
    }

    @Nullable
    @Override
    public Set<String> getStringSet(String key, Set<String> defValues) {
        final Set<String> encryptSet = mSharedPreferences.getStringSet(encryptPreference(key), null);
        if (encryptSet == null){
            return defValues;
        }
        final Set<String> decryptSet = new HashSet<>();
        for (String encryptValue : encryptSet){
            decryptSet.add(decryptPreference(encryptValue));
        }
        return decryptSet;
    }

    @Override
    public int getInt(String key, int defValue) {
        final String encryptValue = mSharedPreferences.getString(encryptPreference(key), null);
        if (encryptValue == null) {
            return defValue;
        }
        return Integer.parseInt(decryptPreference(encryptValue));
    }

    @Override
    public long getLong(String key, long defValue) {
        final String encryptValue = mSharedPreferences.getString(encryptPreference(key), null);
        if (encryptValue == null) {
            return defValue;
        }
        return Long.parseLong(decryptPreference(encryptValue));
    }

    @Override
    public float getFloat(String key, float defValue) {
        final String encryptValue = mSharedPreferences.getString(encryptPreference(key), null);
        if (encryptValue == null) {
            return defValue;
        }
        return Float.parseFloat(decryptPreference(encryptValue));
    }

    @Override
    public boolean getBoolean(String key, boolean defValue) {
        final String encryptValue = mSharedPreferences.getString(encryptPreference(key), null);
        if (encryptValue == null) {
            return defValue;
        }
        return Boolean.parseBoolean(decryptPreference(encryptValue));
    }

    @Override
    public boolean contains(String key) {
        return mSharedPreferences.contains(encryptPreference(key));
    }

    @Override
    public SecurityEditor edit() {
        return new SecurityEditor();
    }

    @Override
    public void registerOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener listener) {
        mSharedPreferences.registerOnSharedPreferenceChangeListener(listener);
    }

    @Override
    public void unregisterOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener listener) {
        mSharedPreferences.unregisterOnSharedPreferenceChangeListener(listener);
    }

    /**
     * 处理加密过渡
     */
    public void handleTransition(){
        Map<String, ?> oldMap = mSharedPreferences.getAll();
        Map<String, String> newMap = new HashMap<>();
        for (Map.Entry<String, ?> entry : oldMap.entrySet()){
            Log.i(TAG, "key:"+entry.getKey()+", value:"+ entry.getValue());
            newMap.put(encryptPreference(entry.getKey()), encryptPreference(entry.getValue().toString()));
        }
        Editor editor = mSharedPreferences.edit();
        editor.clear().commit();
        for (Map.Entry<String, String> entry : newMap.entrySet()){
            editor.putString(entry.getKey(), entry.getValue());
        }
        editor.commit();
    }

    /**
     * 自动加密Editor
     */
    public final class SecurityEditor implements Editor {

        private Editor mEditor;

        /**
         * constructor
         */
        private SecurityEditor(){
            mEditor = mSharedPreferences.edit();
        }

        @Override
        public Editor putString(String key, String value) {
            mEditor.putString(encryptPreference(key), encryptPreference(value));
            return this;
        }

        @Override
        public Editor putStringSet(String key, Set<String> values) {
            final Set<String> encryptSet = new HashSet<>();
            for (String value : values){
                encryptSet.add(encryptPreference(value));
            }
            mEditor.putStringSet(encryptPreference(key), encryptSet);
            return this;
        }

        @Override
        public Editor putInt(String key, int value) {
            mEditor.putString(encryptPreference(key), encryptPreference(Integer.toString(value)));
            return this;
        }

        @Override
        public Editor putLong(String key, long value) {
            mEditor.putString(encryptPreference(key), encryptPreference(Long.toString(value)));
            return this;
        }

        @Override
        public Editor putFloat(String key, float value) {
            mEditor.putString(encryptPreference(key), encryptPreference(Float.toString(value)));
            return this;
        }

        @Override
        public Editor putBoolean(String key, boolean value) {
            mEditor.putString(encryptPreference(key), encryptPreference(Boolean.toString(value)));
            return this;
        }

        @Override
        public Editor remove(String key) {
            mEditor.remove(encryptPreference(key));
            return this;
        }

        /**
         * Mark in the editor to remove all values from the preferences.
         * @return this
         */
        @Override
        public Editor clear() {
            mEditor.clear();
            return this;
        }

        /**
         * 提交数据到本地
         * @return Boolean 判断是否提交成功
         */
        @Override
        public boolean commit() {

            return mEditor.commit();
        }

        /**
         * Unlike commit(), which writes its preferences out to persistent storage synchronously,
         * apply() commits its changes to the in-memory SharedPreferences immediately but starts
         * an asynchronous commit to disk and you won't be notified of any failures.
         */
        @Override
        @TargetApi(Build.VERSION_CODES.GINGERBREAD)
        public void apply() {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
                mEditor.apply();
            } else {
                commit();
            }
        }
    }
}

import android.annotation.SuppressLint;
import android.content.Context;
import android.os.Build;
import android.provider.Settings;
import android.text.TextUtils;
import android.util.Base64;
import android.util.Log;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

/**
 * AES加密解密工具
 */
public class EncryptUtil {

    private String key;
    private static EncryptUtil instance;
    private static final String TAG = EncryptUtil.class.getSimpleName();


    private EncryptUtil(Context context){
        String serialNo = getDeviceSerialNumber(context);
        //加密随机字符串生成AES key
        key = SHA(serialNo + "#$ERDTS$D%F^Gojikbh").substring(0, 16);
        Log.e(TAG, key);
    }

    /**
     * 单例模式
     * @param context context
     * @return
     */
    public static EncryptUtil getInstance(Context context){
        if (instance == null){
            synchronized (EncryptUtil.class){
                if (instance == null){
                    instance = new EncryptUtil(context);
                }
            }
        }

        return instance;
    }

    /**
     * Gets the hardware serial number of this device.
     *
     * @return serial number or Settings.Secure.ANDROID_ID if not available.
     */
    @SuppressLint("HardwareIds")
    private String getDeviceSerialNumber(Context context) {
        // We're using the Reflection API because Build.SERIAL is only available
        // since API Level 9 (Gingerbread, Android 2.3).
        try {
            String deviceSerial = (String) Build.class.getField("SERIAL").get(null);
            if (TextUtils.isEmpty(deviceSerial)) {
                return Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
            } else {
                return deviceSerial;
            }
        } catch (Exception ignored) {
            // Fall back  to Android_ID
            return Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
        }
    }


    /**
     * SHA加密
     * @param strText 明文
     * @return
     */
    private String SHA(final String strText){
        // 返回值
        String strResult = null;
        // 是否是有效字符串
        if (strText != null && strText.length() > 0){
            try{
                // SHA 加密开始
                MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
                // 传入要加密的字符串
                messageDigest.update(strText.getBytes());
                byte byteBuffer[] = messageDigest.digest();
                StringBuffer strHexString = new StringBuffer();
                for (int i = 0; i < byteBuffer.length; i++){
                    String hex = Integer.toHexString(0xff & byteBuffer[i]);
                    if (hex.length() == 1){
                        strHexString.append('0');
                    }
                    strHexString.append(hex);
                }
                strResult = strHexString.toString();
            } catch (NoSuchAlgorithmException e) {
                e.printStackTrace();
            }
        }

        return strResult;
    }


    /**
     * AES128加密
     * @param plainText 明文
     * @return
     */
    public String encrypt(String plainText) {
        try {
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.ENCRYPT_MODE, keyspec);
            byte[] encrypted = cipher.doFinal(plainText.getBytes());
            return Base64.encodeToString(encrypted, Base64.NO_WRAP);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * AES128解密
     * @param cipherText 密文
     * @return
     */
    public String decrypt(String cipherText) {
        try {
            byte[] encrypted1 = Base64.decode(cipherText, Base64.NO_WRAP);
            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
            SecretKeySpec keyspec = new SecretKeySpec(key.getBytes(), "AES");
            cipher.init(Cipher.DECRYPT_MODE, keyspec);
            byte[] original = cipher.doFinal(encrypted1);
            String originalString = new String(original);
            return originalString;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}