java.security.UnrecoverableKeyException: Failed to obtain information about private key
When this error happens and why?
Ans: When loading Android keys and storing public key from Keystore, this error may happen if the state is locked or uninitialized.
Error generating portion code is given below:
@NonNull
public static AndroidKeyStorePublicKey loadAndroidKeyStorePublicKeyFromKeystore(
@NonNull KeyStore keyStore, @NonNull String privateKeyAlias)
throws UnrecoverableKeyException {
KeyCharacteristics keyCharacteristics = new KeyCharacteristics();
int errorCode = keyStore.getKeyCharacteristics(privateKeyAlias, null,
null, keyCharacteristics);
if (errorCode != KeyStore.NO_ERROR) {
throw (UnrecoverableKeyException) new UnrecoverableKeyException(
"Failed to obtain information about private key")
.initCause(KeyStore.getKeyStoreException(errorCode)); // this exception is generated
}
......
......
......
}
KeyStore has 10 response code. They are
// ResponseCodes
NO_ERROR = 1;
LOCKED = 2;
UNINITIALIZED = 3;
SYSTEM_ERROR = 4;
PROTOCOL_ERROR = 5;
PERMISSION_DENIED = 6;
KEY_NOT_FOUND = 7;
VALUE_CORRUPTED = 8;
UNDEFINED_ACTION = 9;
WRONG_PASSWORD = 10;
KeyStore has 3 states. They are UNLOCKED, LOCKED, UNINITIALIZED
NO_ERROR is only happened when the state is UNLOCKED. For your upgrading case the state is LOCKED or UNINITIALIZED for first time, so the error is happened only once.
State Checking code is given below:
public State state() {
execute('t');
switch (mError) {
case NO_ERROR:
return State.UNLOCKED;
case LOCKED:
return State.LOCKED;
case UNINITIALIZED:
return State.UNINITIALIZED;
default:
throw new AssertionError(mError);
}
}
Resource Link:
- AndroidKeyStoreProvider java class
- KeyStore java class
UPDATE:
From your error log, it is now clear that
W/System.err﹕ Caused by: android.security.KeyStoreException: Invalid key blob
this is the main issue which is caused when user tries to UNLOCK from LOCK/UNINITIALIZED. It is by default defined as 30 secs for timing. This problem is it's API related implementation issue.
/**
* If the user has unlocked the device Within the last this number of seconds,
* it can be considered as an authenticator.
*/
private static final int AUTHENTICATION_DURATION_SECONDS = 30;
For encryption/decryption some data with the generated key only works if the user has just authenticated via device credentials. The error occurs from
// Try encrypting something, it will only work if the user authenticated within
// the last AUTHENTICATION_DURATION_SECONDS seconds.
cipher.init(Cipher.ENCRYPT_MODE, secretKey); // error is generated from here.
Actual error is thrown from here. Your error is generated from InvalidKeyException.
Solution:
You have to remove the InvalidKeyException class from the catch argument. This will still allow you to check for InvalidKeyException. After checking you have to try for second time with code so that the problem is not shown in eye but doing 2 times checking it may solve your issue. I have not tested the code but should be like below:
try {
....
KeyStore.PrivateKeyEntry privateKeyEntry = (KeyStore.PrivateKeyEntry) this.keyStore.getEntry("alias", null);
....
} catch (final Exception e) {
e.printStackTrace();
if (e instanceof InvalidKeyException) { // bypass InvalidKeyException
.......
// You can again call the method and make a counter for deadlock situation or implement your own code according to your situation
if (retry) {
keyStore.deleteEntry(keyName);
return getCypher(keyName, false);
} else {
throw e;
}
}
}
Resource Link:
- MainActivity.java
- android.security.KeyStoreException: Invalid key blob
UPDATE (August 2020):
Updating the security library to version 1.0.0-rc03 fixes the problem for me.
In the changle log they mention:
Tink update should gracefully handle AndroidKeyStore concurrency failures.
Old Answer:
There is an open issue on issuetracker for this
Here is a reply of one of Google Engineers
Some OEM implementations of the AndroidKeyStore are broken and do not work properly. Unfortunately, Jetpack Security relies on the AndroidKeyStore to securely store and generate keys. If this is not working, all you can do is trust the devices that have failures, less and not use encryption. Ideally a check would be nice in the library to find these issues so you can know about this without random crashes.
I wrote a test class you could use in the meantime to test the KeyStore. Basically, you have to do an end to end, encrypt/decrypt to know if the device KeyStore is fully working.
https://gist.github.com/jmarkoff/44f5a9cab1a881c8b0abc787791add08
/*
* Copyright 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//packgage com.company.app
import android.content.Context;
import android.content.SharedPreferences;
import android.security.keystore.KeyGenParameterSpec;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.security.crypto.MasterKeys;
import androidx.security.crypto.EncryptedSharedPreferences;
import java.io.IOException;
import java.security.GeneralSecurityException;
/**
* Convenient method to test the Android Keystore before using encryption/decryption. A small number
* OEMs have devices with a bad keystore and KeyStore exceptions will occur.
*
* Requires Jetpack Security - https://developer.android.com/jetpack/androidx/releases/security
*
* Bugs:
*
* https://issuetracker.google.com/issues/147480931
* https://issuetracker.google.com/issues/134417365
* https://issuetracker.google.com/issues/150221071
*
*/
public final class TestKeyStore {
/**
* Test the keystore, encryption and decryption on the device. This is useful to find devices
* that have a bad keystore and encryption should not be used. It is up to the developer to
* decide how to handle when a bad keystore is encountered. We recommend that the device be
* trusted less by your app if possible.
*
* @param keyGenParameterSpec The key encryption scheme
* @return true if the keystore can be relied on, false otherwise
*/
public static boolean trustDeviceKeyStore(@NonNull KeyGenParameterSpec keyGenParameterSpec,
@NonNull Context context) {
try {
String keyAlias = MasterKeys.getOrCreate(keyGenParameterSpec);
SharedPreferences sharedPreferences =
EncryptedSharedPreferences.create("test_keystore", keyAlias,
context,
EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("TestKeyStore", "Testing");
editor.commit();
String value = sharedPreferences.getString("TestKeyStore", "Failed");
if (value.equals("Testing")) {
return true;
}
} catch (GeneralSecurityException ex) {
Log.e(TestKeyStore.class.getSimpleName(),
"SecurityException: Could be a keystore issue, check the error for more "
+ "details message: " + ex.getMessage() + ".\n Stacktrace:\n"
+ ex.getStackTrace().toString());
} catch (IOException ex) {
Log.e(TestKeyStore.class.getSimpleName(),
"IOException: Check to make sure you have enough disk space and that the "
+ "file doesn't exist." + ex.getMessage());
}
return false;
}
}