android - Setup AsyncHttpClient to use HTTPS

Question

I am using com.loopj.android:android-async-http:1.4.9 for my request to server. It was working fine until I SSL/TLS is required in my server. So I need to modify my AsyncHTTPClient to use HTTPS in all URLs.

I checked this similar how to make HTTPS calls using AsyncHttpClient? but did not provide clear solution to the problem. The accepted solution was not secure as well because of this warning from the library itself:

Warning! This omits SSL certificate validation on every device, use with caution.

So I went on and check other solutions. I ended up following the recommendation from: https://developer.android.com/training/articles/security-ssl.html. Thus, I have something similar to this:

// Load CAs from an InputStream
// (could be from a resource or ByteArrayInputStream or ...)
CertificateFactory cf = CertificateFactory.getInstance("X.509");
// From https://www.washington.edu/itconnect/security/ca/load-der.crt
InputStream caInput = new BufferedInputStream(new FileInputStream("load-der.crt"));
Certificate ca;
try {
    ca = cf.generateCertificate(caInput);
    System.out.println("ca=" + ((X509Certificate) ca).getSubjectDN());
} finally {
    caInput.close();
}

// Create a KeyStore containing our trusted CAs
String keyStoreType = KeyStore.getDefaultType();
KeyStore keyStore = KeyStore.getInstance(keyStoreType);
keyStore.load(null, null);
keyStore.setCertificateEntry("ca", ca);

// Create a TrustManager that trusts the CAs in our KeyStore
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
tmf.init(keyStore);

// Create an SSLContext that uses our TrustManager
SSLContext context = SSLContext.getInstance("TLS");
context.init(null, tmf.getTrustManagers(), null);

// Get SocketFactory from our SSLContext
//
//      !!!PROBLEM IS HERE!!!
//   
javax.net.ssl.SSLSocketFactory socketFactory = context.getSocketFactory();

As you can see in the last line, it gives an SSLSocketFactory from javax.net.ssl package. However the AsyncHTTPClient instance requires

asyncHTTPClient.setSSLSocketFactory(cz.msebera.android.httpclient.conn.ssl.SSLSocketFactory)

EDIT:

My server is using a self-signed certificate.

Answer 1

As you can see here, setSSLFactory requires an object of SSLFactory, so you can create your own MySSLFactory class. In the below example I have renamed it to MyCustomSSLFactory. The code for SSL Validaton is in the method checkServerTrusted of X509TrustManager. You can modify it as per your need if needed.

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.UnrecoverableKeyException;
import java.security.cert.Certificate;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import cz.msebera.android.httpclient.HttpVersion;
import cz.msebera.android.httpclient.conn.ClientConnectionManager;
import cz.msebera.android.httpclient.conn.scheme.PlainSocketFactory;
import cz.msebera.android.httpclient.conn.scheme.Scheme;
import cz.msebera.android.httpclient.conn.scheme.SchemeRegistry;
import cz.msebera.android.httpclient.conn.ssl.SSLSocketFactory;
import cz.msebera.android.httpclient.impl.client.DefaultHttpClient;
import cz.msebera.android.httpclient.impl.conn.tsccm.ThreadSafeClientConnManager;
import cz.msebera.android.httpclient.params.BasicHttpParams;
import cz.msebera.android.httpclient.params.HttpParams;
import cz.msebera.android.httpclient.params.HttpProtocolParams;
import cz.msebera.android.httpclient.protocol.HTTP;


/**
 * Created by prerak on 15/03/2017.
 */

public class MyCustomSSLFactory extends SSLSocketFactory {
    final SSLContext sslContext = SSLContext.getInstance("TLS");

    /**
     * Creates a new SSL Socket Factory with the given KeyStore.
     *
     * @param truststore A KeyStore to create the SSL Socket Factory in context of
     * @throws NoSuchAlgorithmException  NoSuchAlgorithmException
     * @throws KeyManagementException    KeyManagementException
     * @throws KeyStoreException         KeyStoreException
     * @throws UnrecoverableKeyException UnrecoverableKeyException
     */
    public MyCustomSSLFactory(KeyStore truststore) throws NoSuchAlgorithmException, KeyManagementException, KeyStoreException, UnrecoverableKeyException {
        super(truststore);

        X509TrustManager tm = new X509TrustManager() {
            public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
            }

            public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
                try {
                    chain[0].checkValidity();
                } catch (Exception e) {
                    throw new CertificateException("Certificate not valid or trusted.");
                }
            }

            public X509Certificate[] getAcceptedIssuers() {
                return null;
            }
        };

        sslContext.init(null, new TrustManager[]{tm}, null);
    }

    /**
     * Gets a KeyStore containing the Certificate
     *
     * @param cert InputStream of the Certificate
     * @return KeyStore
     */
    public static KeyStore getKeystoreOfCA(InputStream cert) {

        // Load CAs from an InputStream
        InputStream caInput = null;
        Certificate ca = null;
        try {
            CertificateFactory cf = CertificateFactory.getInstance("X.509");
            caInput = new BufferedInputStream(cert);
            ca = cf.generateCertificate(caInput);
        } catch (CertificateException e1) {
            e1.printStackTrace();
        } finally {
            try {
                if (caInput != null) {
                    caInput.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        // Create a KeyStore containing our trusted CAs
        String keyStoreType = KeyStore.getDefaultType();
        KeyStore keyStore = null;
        try {
            keyStore = KeyStore.getInstance(keyStoreType);
            keyStore.load(null, null);
            keyStore.setCertificateEntry("ca", ca);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return keyStore;
    }

    /**
     * Gets a Default KeyStore
     *
     * @return KeyStore
     */
    public static KeyStore getKeystore() {
        KeyStore trustStore = null;
        try {
            trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
            trustStore.load(null, null);
        } catch (Throwable t) {
            t.printStackTrace();
        }
        return trustStore;
    }

    /**
     * Returns a SSlSocketFactory which trusts all certificates
     *
     * @return SSLSocketFactory
     */
    public static SSLSocketFactory getFixedSocketFactory() {
        SSLSocketFactory socketFactory;
        try {
            socketFactory = new MyCustomSSLFactory(getKeystore());
            socketFactory.setHostnameVerifier(SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
        } catch (Throwable t) {
            t.printStackTrace();
            socketFactory = SSLSocketFactory.getSocketFactory();
        }
        return socketFactory;
    }

    /**
     * Gets a DefaultHttpClient which trusts a set of certificates specified by the KeyStore
     *
     * @param keyStore custom provided KeyStore instance
     * @return DefaultHttpClient
     */
    public static DefaultHttpClient getNewHttpClient(KeyStore keyStore) {

        try {
            SSLSocketFactory sf = new MyCustomSSLFactory(keyStore);
            SchemeRegistry registry = new SchemeRegistry();
            registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
            registry.register(new Scheme("https", sf, 443));

            HttpParams params = new BasicHttpParams();
            HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
            HttpProtocolParams.setContentCharset(params, HTTP.UTF_8);

            ClientConnectionManager ccm = new ThreadSafeClientConnManager(params, registry);

            return new DefaultHttpClient(ccm, params);
        } catch (Exception e) {
            return new DefaultHttpClient();
        }
    }

    @Override
    public Socket createSocket(Socket socket, String host, int port, boolean autoClose) throws IOException {
        return sslContext.getSocketFactory().createSocket(socket, host, port, autoClose);
    }

    @Override
    public Socket createSocket() throws IOException {
        return sslContext.getSocketFactory().createSocket();
    }

    /**
     * Makes HttpsURLConnection trusts a set of certificates specified by the KeyStore
     */
    public void fixHttpsURLConnection() {
        HttpsURLConnection.setDefaultSSLSocketFactory(sslContext.getSocketFactory());
    }
}

Now you can initialise an object of MyCustomSSLSocketFactory by passing your custom KeyStore to it.

MyCustomSSLFactory socketFactory = new MyCustomSSLFactory(keyStore);

And now you can set the socket factory as:

asyncHTTPClient.setSSLSocketFactory(socketFactory);