Using .pfx certificate in https request error

Question

I have a problem using pfx certificate in my app. I've really tried to do a lot, but I can't send the certificate properly.

public class WebApiManager {

    private static WebApiManager webApiManager;

    private Context appContext;
    private WebApi webApi;
    private OkHttpClient.Builder client;

    private WebApiManager(Context appContext) {
        this.appContext = appContext;
    }

    public static WebApiManager get(Context context) {
        if (webApiManager == null) {
            webApiManager = new WebApiManager(context.getApplicationContext());
        }
        return webApiManager;
    }

    Gson gson = new GsonBuilder()
            .setLenient()
            .create();

    public WebApi getWebApi() throws UnrecoverableKeyException, CertificateException, KeyStoreException, IOException, NoSuchAlgorithmException, KeyManagementException {
        if (webApi == null) {
            webApi = new Retrofit.Builder()
                    .baseUrl(WebApi.BASE_URL)
                    .client(getOkHttpClient())
                    .addConverterFactory(GsonConverterFactory.create(gson))
                    .build()
                    .create(WebApi.class);
        }
        return webApi;
    }

    OkHttpClient getOkHttpClient() throws KeyStoreException, CertificateException, IOException, NoSuchAlgorithmException, KeyManagementException, UnrecoverableKeyException {

        client = new OkHttpClient.Builder()
                .connectTimeout(WebApi.TIMEOUT, TimeUnit.SECONDS)
                .readTimeout(WebApi.TIMEOUT, TimeUnit.SECONDS);

        InputStream inputStream = appContext.getResources().openRawResource(R.raw.stefan);
        KeyStore keyStore = KeyStore.getInstance("PKCS12");
        keyStore.load(inputStream, "nusiceva5".toCharArray());

        SSLContext sslContext = SSLContext.getInstance("TLS");
        KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance("X509");
        keyManagerFactory.init(keyStore, "nusiceva5".toCharArray());

        sslContext.init(keyManagerFactory.getKeyManagers(), null, null);

        return client
                .sslSocketFactory(sslContext.getSocketFactory())
                .protocols(Util.immutableListOf(Protocol.HTTP_1_1))
                .build();
    }
}

And the error i make.

java.io.IOException: exception unwrapping private key - java.security.NoSuchAlgorithmException: 1.2.840.113549.1.5.12 SecretKeyFactory not available W/System.err: at com.android.org.bouncycastle.jcajce.provider.keystore.pkcs12.PKCS12KeyStoreSpi.unwrapKey(PKCS12KeyStoreSpi.java:652) W/System.err: at com.android.org.bouncycastle.jcajce.provider.keystore.pkcs12.PKCS12KeyStoreSpi.engineLoad(PKCS12KeyStoreSpi.java:891) W/System.err: at java.security.KeyStore.load(KeyStore.java:1484)