问题可能很长，但我会尽量详细描述。
这是一个演示，有我的问题。
我有一个 android 应用程序，我想添加一个函数，允许用户在 SharedPreferences 中加密和保存他们的密码，并从 SharedPreferences 读取和解密它们。仅当指纹已注册且指纹有效可作为验证方式获取这些密码时才可用。
存储时：
- 用户输入密码
- 通过 AndroidKeyStore 生成的 SecretKey 创建加密模式密码
public Cipher getEncryptCipher() {
try {
Cipher cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
+ KeyProperties.BLOCK_MODE_CBC + "/"
+ KeyProperties.ENCRYPTION_PADDING_PKCS7);
mKeyStore.load(null);
SecretKey key = (SecretKey) mKeyStore.getKey(KEY_NAME, null);
cipher.init(Cipher.ENCRYPT_MODE, key);
return cipher;
} catch (Exception e) {
throw new RuntimeException("Failed to encrypt pin ", e);
}
}
- FingerprintManager 验证密码（密码 A）并获得真正的加密密码（密码 B）
//mCryptoObject is generated by cipher in step 2
mFingerprintManager.authenticate(mCryptoObject, mCancellationSignal, 0 /* flags */, FingerprintManager.AuthenticationCallback, null);
//in FingerprintManager.AuthenticationCallback
javax.crypto.Cipher cipher = result.getCryptoObject().getCipher();
- 由指纹管理器支持的密码（密码 B）加密密码
- 在 SharedPreferences 中存储加密的密码和密码 iv
//In my app, we have many device, every could have one password. Pin is password.
public void encryptPin(String deviceId, String pin, javax.crypto.Cipher cipher) {
try {
if (cipher == null) return;
byte[] encryptedBytes = cipher.doFinal(pin.getBytes("utf-8"));
byte[] cipherIv = cipher.getIV();
String encodedPin = Base64.encodeToString(encryptedBytes, Base64.DEFAULT);
String encodeCipherIv = Base64.encodeToString(cipherIv, Base64.DEFAULT);
SharedPreferences.Editor editor = mSharedPreferences.edit();
editor.putString(createPinKey(deviceId), encodedPin);
editor.putString(createIvKey(deviceId), encodeCipherIv);
editor.apply();
} catch (IOException | IllegalBlockSizeException | BadPaddingException e) {
throw new RuntimeException("Failed to encrypt pin ", e);
}
}
阅读时：
- 读取密码 iv 并创建解密模式密码（密码 C）
public Cipher getDecryptCipher(String deviceId) {
try {
String encodedIv = mSharedPreferences.getString(createIvKey(deviceId), "");
byte[] cipherIv = Base64.decode(encodedIv, Base64.DEFAULT);
Cipher cipher = Cipher.getInstance(KeyProperties.KEY_ALGORITHM_AES + "/"
+ KeyProperties.BLOCK_MODE_CBC + "/"
+ KeyProperties.ENCRYPTION_PADDING_PKCS7);
mKeyStore.load(null);
SecretKey key = (SecretKey) mKeyStore.getKey(KEY_NAME, null);
cipher.init(Cipher.DECRYPT_MODE, key, new IvParameterSpec(cipherIv));
return cipher;
} catch (Exception e) {
throw new RuntimeException("Failed to encrypt pin ", e);
}
}
- 有效指纹并获得真正的解密密码（密码D）
//mCryptoObject is generated by cipher in step 1
mFingerprintManager.authenticate(mCryptoObject, mCancellationSignal, 0 /* flags */, FingerprintManager.AuthenticationCallback, null);
//in FingerprintManager.AuthenticationCallback
javax.crypto.Cipher cipher = result.getCryptoObject().getCipher();
- 读取加密密码并用真正的解密密码（密码D）解密
public String decryptPin(String deviceId, javax.crypto.Cipher cipher) {
String encryptedPin = mSharedPreferences.getString(createPinKey(deviceId), "");
if (TextUtils.isEmpty(encryptedPin)) {
return "";
}
try {
if (cipher == null) return "";
byte[] decodedBytes = Base64.decode(encryptedPin, Base64.DEFAULT);
//BadPaddingException in this line
byte[] decryptBytes = cipher.doFinal(decodedBytes);
return new String(decryptBytes, Charset.forName("UTF8"));
} catch (Exception e) {
MyLog.d(TAG, "Failed to decrypt the data with the generated key." + e.getMessage());
e.printStackTrace();
return "";
}
}
我的初始化方法：
private void init() {
try {
mKeyStore = KeyStore.getInstance("AndroidKeyStore");
mKeyStore.load(null);
KeyGenParameterSpec.Builder builder = new KeyGenParameterSpec.Builder(KEY_NAME,
KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
.setBlockModes(KeyProperties.BLOCK_MODE_CBC)
.setUserAuthenticationRequired(true)
.setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
builder.setInvalidatedByBiometricEnrollment(true);
}
KeyGenerator keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, "AndroidKeyStore");
keyGenerator.init(
builder.build());
keyGenerator.generateKey();
} catch (Exception e) {
throw new RuntimeException("Fail to init:" + e);
}
}
如果不关闭应用程序一切正常！！！
但是，当我终止进程并重新启动它时，在执行 cipher.doFinal() 时，我在 decryptPin() 方法中得到了 BadPaddingException。
System.err: javax.crypto.BadPaddingException
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:482)
at javax.crypto.Cipher.doFinal(Cipher.java:1502)
at com.xiaomi.smarthome.framework.page.verify.DeviceVerifyConfigCache.decryptPin(DeviceVerifyConfigCache.java:156)
at com.xiaomi.smarthome.framework.page.verify.VerifyManager.decryptPin(VerifyManager.java:173)
at com.xiaomi.smarthome.framework.page.verify.FingerPrintVerifyActivity$1.onAuthenticated(FingerPrintVerifyActivity.java:62)
at com.xiaomi.smarthome.framework.page.verify.view.FingerPrintOpenVerifyDialog.onAuthenticationSucceeded(FingerPrintOpenVerifyDialog.java:136)
at android.hardware.fingerprint.FingerprintManager$MyHandler.sendAuthenticatedSucceeded(FingerprintManager.java:805)
at android.hardware.fingerprint.FingerprintManager$MyHandler.handleMessage(FingerprintManager.java:757)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5458)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:738)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:628)
Caused by: android.security.KeyStoreException: Invalid argument
at android.security.KeyStore.getKeyStoreException(KeyStore.java:632)
at android.security.keystore.KeyStoreCryptoOperationChunkedStreamer.doFinal(KeyStoreCryptoOperationChunkedStreamer.java:224)
at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineDoFinal(AndroidKeyStoreCipherSpiBase.java:473)
... 13 more
有谁可以帮我解决这个问题？是不是SecretKey引起的？谢谢！！！