功能简介:SharePreference工具类，提供两种类型的sharePreference，一种是系统的，另一种是加密的
一.加密工具类
/**
* 加密和普通的SharedPreferences工具类
* Created by caoshiyao on 2016/8/13.
*/
public class PreferenceUtil {
private static final String DEFAULT = "DEFAULT";
private static final String SECURE = "SECURE_YAO";
private static boolean sSecurePreferenceInited = false;
private static SecurePreferences sSecurePreferences;
private static SharedPreferences sSharedPreferences;
private static final Object sLock = new Object();
public static SharedPreferences getDefaultPreference(final Context context) {
return context.getSharedPreferences(DEFAULT, Context.MODE_PRIVATE);
}
public static synchronized SharedPreferences getSecurePreference() {
synchronized (sLock) {
if (sSecurePreferences == null) {
if (sSecurePreferenceInited) {
return sSharedPreferences;
}
throw new IllegalStateException(
"initSecurePreference must be called at least once!!!");
}
return sSecurePreferences;
}
}
/**
* 初始化SecurePreferences，应该在应用启动的时候调用
*
* @param context
*/
public static void initSecurePreference(final Context context) {
synchronized (sLock) {
sSecurePreferenceInited = true;
if (sSecurePreferences != null) return;
try {
sSecurePreferences = new SecurePreferences(context, "666yao888", SECURE);
} catch (Exception e) { //部分机型不支持特点的加密算法，导致崩溃
sSharedPreferences = context.getSharedPreferences(DEFAULT, Context.MODE_PRIVATE);
e.printStackTrace();
}
}
}
}
自定义的加密SecurePreferences
public class SecurePreferences implements SharedPreferences {
private static final int ORIGINAL_ITERATION_COUNT = 10000;
//the backing pref file
private SharedPreferences sharedPreferences;
//secret keys used for enc and dec
private AesCbcWithIntegrity.SecretKeys keys;
//the salt used for enc and dec
private String salt;
private static boolean sLoggingEnabled = false;
private static final String TAG = SecurePreferences.class.getName();
//name of the currently loaded sharedPrefFile, can be null if default
private String sharedPrefFilename;
/**
* User password defaults to app generated password that's stores obfucated with the other preference values. Also this uses the Default shared pref file
*
* @param context should be ApplicationContext not Activity
*/
public SecurePreferences(Context context) {
this(context, "", null);
}
/**
* @param context should be ApplicationContext not Activity
* @param iterationCount The iteration count for the keys generation
*/
public SecurePreferences(Context context, int iterationCount) {
this(context, "", null, iterationCount);
}
/**
* @param context should be ApplicationContext not Activity
* @param password user password/code used to generate encryption key.
* @param sharedPrefFilename name of the shared pref file. If null use the default shared prefs
*/
public SecurePreferences(Context context, final String password, final String sharedPrefFilename) {
this(context, password, null, sharedPrefFilename, ORIGINAL_ITERATION_COUNT);
}
/**
* @param context should be ApplicationContext not Activity
* @param iterationCount The iteration count for the keys generation
*/
public SecurePreferences(Context context, final String password, final String sharedPrefFilename, int iterationCount) {
this(context, null, password, null, sharedPrefFilename, iterationCount);
}
/**
* @param context should be ApplicationContext not Activity
* @param secretKey that you've generated
* @param sharedPrefFilename name of the shared pref file. If null use the default shared prefs
*/
public SecurePreferences(Context context, final AesCbcWithIntegrity.SecretKeys secretKey, final String sharedPrefFilename) {
this(context, secretKey, null, null, sharedPrefFilename, 0);
}
/**
* @param context should be ApplicationContext not Activity
* @param iterationCount The iteration count for the keys generation
*/
public SecurePreferences(Context context, final String password, final String salt, final String sharedPrefFilename, int iterationCount) {
this(context, null, password, salt, sharedPrefFilename, iterationCount);
}
private SecurePreferences(Context context, final AesCbcWithIntegrity.SecretKeys secretKey, final String password, final String salt, final String sharedPrefFilename, int iterationCount) {
if (sharedPreferences == null) {
sharedPreferences = getSharedPreferenceFile(context, sharedPrefFilename);
}
this.salt = salt;
if (secretKey != null) {
keys = secretKey;
} else if (TextUtils.isEmpty(password)) {
// Initialize or create encryption key
try {
final String key = generateAesKeyName(context, iterationCount);
String keyAsString = sharedPreferences.getString(key, null);
if (keyAsString == null) {
keys = AesCbcWithIntegrity.generateKey();
//saving new key
boolean committed = sharedPreferences.edit().putString(key, keys.toString()).commit();
if (!committed) {
Log.w(TAG, "Key not committed to prefs");
}
} else {
keys = AesCbcWithIntegrity.keys(keyAsString);
}
if (keys == null) {
throw new GeneralSecurityException("Problem generating Key");
}
} catch (GeneralSecurityException e) {
if (sLoggingEnabled) {
Log.e(TAG, "Error init:" + e.getMessage());
}
throw new IllegalStateException(e);
}
} else {
//use the password to generate the key
try {
final byte[] saltBytes = getSalt(context).getBytes();
keys = AesCbcWithIntegrity.generateKeyFromPassword(password, saltBytes, iterationCount);
if (keys == null) {
throw new GeneralSecurityException("Problem generating Key From Password");
}
} catch (GeneralSecurityException e) {
if (sLoggingEnabled) {
Log.e(TAG, "Error init using user password:" + e.getMessage());
}
throw new IllegalStateException(e);
}
}
}
/**
* if a prefFilename is not defined the getDefaultSharedPreferences is used.
*
* @param context should be ApplicationContext not Activity
* @return
*/
private SharedPreferences getSharedPreferenceFile(Context context, String prefFilename) {
this.sharedPrefFilename = prefFilename;
if (TextUtils.isEmpty(prefFilename)) {
return PreferenceManager
.getDefaultSharedPreferences(context);
} else {
return context.getSharedPreferences(prefFilename, Context.MODE_PRIVATE);
}
}
/**
* nulls in memory keys
*/
public void destroyKeys() {
keys = null;
}
/**
* Uses device and application values to generate the pref key for the encryption key
*
* @param context should be ApplicationContext not Activity
* @param iterationCount The iteration count for the keys generation
* @return String to be used as the AESkey Pref key
* @throws GeneralSecurityException if something goes wrong in generation
*/
private String generateAesKeyName(Context context, int iterationCount) throws GeneralSecurityException {
final String password = context.getPackageName();
final byte[] salt = getSalt(context).getBytes();
AesCbcWithIntegrity.SecretKeys generatedKeyName = AesCbcWithIntegrity.generateKeyFromPassword(password, salt, iterationCount);
return hashPrefKey(generatedKeyName.toString());
}
/**
* Gets the hardware serial number of this device.
*
* @return serial number or Settings.Secure.ANDROID_ID if not available.
*/
@SuppressLint("HardwareIds")
private static 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);
}
}
/**
* Gets the salt value
*
* @param context used for accessing hardware serial number of this device in case salt is not set
* @return
*/
private String getSalt(Context context) {
if (TextUtils.isEmpty(this.salt)) {
return getDeviceSerialNumber(context);
} else {
return this.salt;
}
}
/**
* The Pref keys must be same each time so we're using a hash to obscure the stored value
*
* @param prefKey
* @return SHA-256 Hash of the preference key
*/
public static String hashPrefKey(String prefKey) {
final MessageDigest digest;
try {
digest = MessageDigest.getInstance("SHA-256");
byte[] bytes = prefKey.getBytes("UTF-8");
digest.update(bytes, 0, bytes.length);
return Base64.encodeToString(digest.digest(), AesCbcWithIntegrity.BASE64_FLAGS);
} catch (NoSuchAlgorithmException | UnsupportedEncodingException e) {
if (sLoggingEnabled) {
Log.w(TAG, "Problem generating hash", e);
}
}
return null;
}
private String encrypt(String cleartext) {
if (TextUtils.isEmpty(cleartext)) {
return cleartext;
}
try {
return AesCbcWithIntegrity.encrypt(cleartext, keys).toString();
} catch (GeneralSecurityException e) {
if (sLoggingEnabled) {
Log.w(TAG, "encrypt", e);
}
return null;
} catch (UnsupportedEncodingException e) {
if (sLoggingEnabled) {
Log.w(TAG, "encrypt", e);
}
}
return null;
}
/**
* @param ciphertext
* @return decrypted plain text, unless decryption fails, in which case null
*/
private String decrypt(final String ciphertext) {
if (TextUtils.isEmpty(ciphertext)) {
return ciphertext;
}
try {
AesCbcWithIntegrity.CipherTextIvMac cipherTextIvMac = new AesCbcWithIntegrity.CipherTextIvMac(ciphertext);
return AesCbcWithIntegrity.decryptString(cipherTextIvMac, keys);
} catch (GeneralSecurityException | UnsupportedEncodingException e) {
if (sLoggingEnabled) {
Log.w(TAG, "decrypt", e);
}
}
return null;
}
/**
* @return map of with decrypted values (excluding the key if present)
*/
@Override
public Map<String, String> getAll() {
//wont be null as per http://androidxref.com/5.1.0_r1/xref/frameworks/base/core/java/android/app/SharedPreferencesImpl.java
final Map<String, ?> encryptedMap = sharedPreferences.getAll();
final Map<String, String> decryptedMap = new HashMap<String, String>(
encryptedMap.size());
for (Entry<String, ?> entry : encryptedMap.entrySet()) {
try {
Object cipherText = entry.getValue();
//don't include the key
if (cipherText != null && !cipherText.equals(keys.toString())) {
//the prefs should all be strings
decryptedMap.put(entry.getKey(),
decrypt(cipherText.toString()));
}
} catch (Exception e) {
if (sLoggingEnabled) {
Log.w(TAG, "error during getAll", e);
}
// Ignore issues that unencrypted values and use instead raw cipher text string
decryptedMap.put(entry.getKey(),
entry.getValue().toString());
}
}
return decryptedMap;
}
@Override
public String getString(String key, String defaultValue) {
final String encryptedValue = sharedPreferences.getString(
SecurePreferences.hashPrefKey(key), null);
String decryptedValue = decrypt(encryptedValue);
if (encryptedValue != null && decryptedValue != null) {
return decryptedValue;
} else {
return defaultValue;
}
}
/**
* Added to get a values as as it can be useful to store values that are
* already encrypted and encoded
*
* @param key pref key
* @param defaultValue
* @return Encrypted value of the key or the defaultValue if no value exists
*/
public String getEncryptedString(String key, String defaultValue) {
final String encryptedValue = sharedPreferences.getString(
SecurePreferences.hashPrefKey(key), null);
return (encryptedValue != null) ? encryptedValue : defaultValue;
}
@Override
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public Set<String> getStringSet(String key, Set<String> defaultValues) {
final Set<String> encryptedSet = sharedPreferences.getStringSet(
SecurePreferences.hashPrefKey(key), null);
if (encryptedSet == null) {
return defaultValues;
}
final Set<String> decryptedSet = new HashSet<String>(
encryptedSet.size());
for (String encryptedValue : encryptedSet) {
decryptedSet.add(decrypt(encryptedValue));
}
return decryptedSet;
}
@Override
public int getInt(String key, int defaultValue) {
final String encryptedValue = sharedPreferences.getString(
SecurePreferences.hashPrefKey(key), null);
if (encryptedValue == null) {
return defaultValue;
}
try {
return Integer.parseInt(decrypt(encryptedValue));
} catch (NumberFormatException e) {
throw new ClassCastException(e.getMessage());
}
}
@Override
public long getLong(String key, long defaultValue) {
final String encryptedValue = sharedPreferences.getString(
SecurePreferences.hashPrefKey(key), null);
if (encryptedValue == null) {
return defaultValue;
}
try {
return Long.parseLong(decrypt(encryptedValue));
} catch (NumberFormatException e) {
throw new ClassCastException(e.getMessage());
}
}
@Override
public float getFloat(String key, float defaultValue) {
final String encryptedValue = sharedPreferences.getString(
SecurePreferences.hashPrefKey(key), null);
if (encryptedValue == null) {
return defaultValue;
}
try {
return Float.parseFloat(decrypt(encryptedValue));
} catch (NumberFormatException e) {
throw new ClassCastException(e.getMessage());
}
}
@Override
public boolean getBoolean(String key, boolean defaultValue) {
final String encryptedValue = sharedPreferences.getString(
SecurePreferences.hashPrefKey(key), null);
if (encryptedValue == null) {
return defaultValue;
}
try {
return Boolean.parseBoolean(decrypt(encryptedValue));
} catch (NumberFormatException e) {
throw new ClassCastException(e.getMessage());
}
}
@Override
public boolean contains(String key) {
return sharedPreferences.contains(SecurePreferences.hashPrefKey(key));
}
/**
* Cycle through the unencrypt all the current prefs to mem cache, clear, then encypt with key generated from new password.
* This method can be used if switching from the generated key to a key derived from user password
* <p>
* Note: the pref keys will remain the same as they are SHA256 hashes.
*
* @param newPassword
* @param context should be ApplicationContext not Activity
* @param iterationCount The iteration count for the keys generation
*/
@SuppressLint("CommitPrefEdits")
public void handlePasswordChange(String newPassword, Context context, int iterationCount) throws GeneralSecurityException {
final byte[] salt = getSalt(context).getBytes();
AesCbcWithIntegrity.SecretKeys newKey = AesCbcWithIntegrity.generateKeyFromPassword(newPassword, salt, iterationCount);
Map<String, ?> allOfThePrefs = sharedPreferences.getAll();
Map<String, String> unencryptedPrefs = new HashMap<String, String>(allOfThePrefs.size());
//iterate through the current prefs unencrypting each one
for (String prefKey : allOfThePrefs.keySet()) {
Object prefValue = allOfThePrefs.get(prefKey);
if (prefValue instanceof String) {
//all the encrypted values will be Strings
final String prefValueString = (String) prefValue;
final String plainTextPrefValue = decrypt(prefValueString);
unencryptedPrefs.put(prefKey, plainTextPrefValue);
}
}
//destroy and clear the current pref file
destroyKeys();
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.clear();
editor.commit();
//refresh the sharedPreferences object ref: I found it was retaining old ref/values
sharedPreferences = null;
sharedPreferences = getSharedPreferenceFile(context, sharedPrefFilename);
//assign new key
this.keys = newKey;
SharedPreferences.Editor updatedEditor = sharedPreferences.edit();
//iterate through the unencryptedPrefs encrypting each one with new key
Iterator<String> unencryptedPrefsKeys = unencryptedPrefs.keySet().iterator();
while (unencryptedPrefsKeys.hasNext()) {
String prefKey = unencryptedPrefsKeys.next();
String prefPlainText = unencryptedPrefs.get(prefKey);
updatedEditor.putString(prefKey, encrypt(prefPlainText));
}
updatedEditor.commit();
}
public void handlePasswordChange(String newPassword, Context context) throws GeneralSecurityException {
handlePasswordChange(newPassword, context, ORIGINAL_ITERATION_COUNT);
}
@Override
public Editor edit() {
return new Editor();
}
/**
* Wrapper for Android's {@link android.content.SharedPreferences.Editor}.
* <p>
* Used for modifying values in a {@link SecurePreferences} object. All
* changes you make in an editor are batched, and not copied back to the
* original {@link SecurePreferences} until you call {@link #commit()} or
* {@link #apply()}.
*/
public final class Editor implements SharedPreferences.Editor {
private SharedPreferences.Editor mEditor;
/**
* Constructor.
*/
private Editor() {
mEditor = sharedPreferences.edit();
}
@Override
public SharedPreferences.Editor putString(String key, String value) {
mEditor.putString(SecurePreferences.hashPrefKey(key),
encrypt(value));
return this;
}
/**
* This is useful for storing values that have be encrypted by something
* else or for testing
*
* @param key - encrypted as usual
* @param value will not be encrypted
* @return
*/
public SharedPreferences.Editor putUnencryptedString(String key,
String value) {
mEditor.putString(SecurePreferences.hashPrefKey(key), value);
return this;
}
@Override
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public SharedPreferences.Editor putStringSet(String key,
Set<String> values) {
final Set<String> encryptedValues = new HashSet<String>(
values.size());
for (String value : values) {
encryptedValues.add(encrypt(value));
}
mEditor.putStringSet(SecurePreferences.hashPrefKey(key),
encryptedValues);
return this;
}
@Override
public SharedPreferences.Editor putInt(String key, int value) {
mEditor.putString(SecurePreferences.hashPrefKey(key),
encrypt(Integer.toString(value)));
return this;
}
@Override
public SharedPreferences.Editor putLong(String key, long value) {
mEditor.putString(SecurePreferences.hashPrefKey(key),
encrypt(Long.toString(value)));
return this;
}
@Override
public SharedPreferences.Editor putFloat(String key, float value) {
mEditor.putString(SecurePreferences.hashPrefKey(key),
encrypt(Float.toString(value)));
return this;
}
@Override
public SharedPreferences.Editor putBoolean(String key, boolean value) {
mEditor.putString(SecurePreferences.hashPrefKey(key),
encrypt(Boolean.toString(value)));
return this;
}
@Override
public SharedPreferences.Editor remove(String key) {
mEditor.remove(SecurePreferences.hashPrefKey(key));
return this;
}
@Override
public SharedPreferences.Editor clear() {
mEditor.clear();
return this;
}
@Override
public boolean commit() {
return mEditor.commit();
}
@Override
@TargetApi(Build.VERSION_CODES.GINGERBREAD)
public void apply() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
mEditor.apply();
} else {
commit();
}
}
}
public static boolean isLoggingEnabled() {
return sLoggingEnabled;
}
public static void setLoggingEnabled(boolean loggingEnabled) {
sLoggingEnabled = loggingEnabled;
}
@Override
public void registerOnSharedPreferenceChangeListener(
final OnSharedPreferenceChangeListener listener) {
sharedPreferences
.registerOnSharedPreferenceChangeListener(listener);
}
/**
* @param listener OnSharedPreferenceChangeListener
* @param decryptKeys Callbacks receive the "key" parameter decrypted
*/
public void registerOnSharedPreferenceChangeListener(
final OnSharedPreferenceChangeListener listener, boolean decryptKeys) {
if (!decryptKeys) {
registerOnSharedPreferenceChangeListener(listener);
}
}
@Override
public void unregisterOnSharedPreferenceChangeListener(
OnSharedPreferenceChangeListener listener) {
sharedPreferences
.unregisterOnSharedPreferenceChangeListener(listener);
}
}
其中需要在app的build.gradle中添加AES的依赖库
compile 'com.scottyab:aes-crypto:0.0.5'
使用之前先在Application中初始化
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
//初始化加密SP
PreferenceUtil.initSecurePreference(getApplicationContext());
}
}
二.普通的SharePreferences工具类
/**
* 普通的SharedPreferences工具类
* Created by caoshiyao on 2016/8/13.
*/
public class SPUtil {
private static String PRI_TOKEN = "token";
/**
* 设置token
*
* @param context
* @param token
*/
public static void setToken(Context context, String token) {
SharedPreferences sharedPreferences = context.getSharedPreferences(PRI_TOKEN, Context.MODE_PRIVATE);
SharedPreferences.Editor edit = sharedPreferences.edit();
edit.putString("token", token);
edit.commit();
}
/**
* 获取token
*
* @param context
* @return
*/
public static String getToken(Context context) {
SharedPreferences sharedPreferences = context.getSharedPreferences(PRI_TOKEN, Context.MODE_PRIVATE);
return sharedPreferences.getString("token", "");
}
}
1.保存数据
String token = "1234567";
//普通SP工具类
SPUtil.setToken(MainActivity.this, token);
//加密SP工具类,使用加密存储
PreferenceUtil.getSecurePreference()
.edit()
.putString("secureToken", token)
.commit();
//加密SP工具类,使用非加密存储
PreferenceUtil.getDefaultPreference(MainActivity.this)
.edit()
.putString("",token)
.commit();
2.获取数据
//普通SP工具类
String tokenInfo = SPUtil.getToken(MainActivity.this);
//加密工具类获取加密数据
String secureToken = PreferenceUtil.getSecurePreference().getString("secureToken", "");
//加密工具类获取非加密数据
String noEncryptionToken = PreferenceUtil.getDefaultPreference(MainActivity.this).getString("", "");
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