java - Android 9 - KeyStore exception android.os.ServiceSpecificException

Question

If I run this code on Android 9, I receive the follow exception:

private static KeyStore.PrivateKeyEntry getPrivateKeyEntry(String alias) {
        try {
            KeyStore ks = KeyStore
                    .getInstance(SecurityConstants.KEYSTORE_PROVIDER_ANDROID_KEYSTORE);
            ks.load(null);
            KeyStore.Entry entry = ks.getEntry(alias, null);

            if (entry == null) {
                Log.w(TAG, "No key found under alias: " + alias);
                Log.w(TAG, "Exiting signData()...");
                return null;
            }

            if (!(entry instanceof KeyStore.PrivateKeyEntry)) {
                Log.w(TAG, "Not an instance of a PrivateKeyEntry");
                Log.w(TAG, "Exiting signData()...");
                return null;
            }
            return (KeyStore.PrivateKeyEntry) entry;
        } catch (Exception e) {
            Log.e(TAG, e.getMessage(), e);
            return null;
        }
    }

Exception:

KeyStore exception android.os.ServiceSpecificException: (code 7) at android.os.Parcel.createException(Parcel.java:1956) at android.os.Parcel.readException(Parcel.java:1910) at android.os.Parcel.readException(Parcel.java:1860) at android.security.IKeystoreService$Stub$Proxy.get(IKeystoreService.java:786) at android.security.KeyStore.get(KeyStore.java:195) at android.security.keystore.AndroidKeyStoreSpi.engineGetCertificateChain(AndroidKeyStoreSpi.java:118) at java.security.KeyStoreSpi.engineGetEntry(KeyStoreSpi.java:484) at java.security.KeyStore.getEntry(KeyStore.java:1560) at com.phenodev.testenc.KeyStoreHelper.getPrivateKeyEntry(KeyStoreHelper.java:151) at com.phenodev.testenc.KeyStoreHelper.encrypt(KeyStoreHelper.java:173) at com.phenodev.testenc.KeyStoreEncryptor.encrypt(KeyStoreEncryptor.java:19)

Please help to fix it.

Answer 1

Finally I found a solution. It looks like since Android P (KeyStore.PrivateKeyEntry) keyStore.getEntry("alias", null) is not a proper way to get private key.

I was able to get rid of this warning by accessing private/public key this way

KeyStore keyStore = KeyStore.getInstance("AndroidKeyStore");
keyStore.load(null);

PrivateKey privateKey = (PrivateKey) keyStore.getKey("alias", null);
PublicKey publicKey = keyStore.getCertificate("alias").getPublicKey();