javax.net.ssl.SSLException: SSL handshake aborted on android old devices

Question

I have android application that was working fine for most of devices Recently some hackers tried to make DDOS attack on our servers that force us to add some security and so

Answer 1

Different Android API levels have different support for SSL/TLS protocols versions, for details see in Android Documention - https://developer.android.com/reference/javax/net/ssl/SSLSocket.html

To enable TLS 1.1 and 1.2 you need to create a custom SSLSocketFactory - https://blog.dev-area.net/2015/08/13/android-4-1-enable-tls-1-1-and-tls-1-2/

public class TLSSocketFactory extends SSLSocketFactory {

    private SSLSocketFactory internalSSLSocketFactory;

    public TLSSocketFactory() throws KeyManagementException, NoSuchAlgorithmException {
        SSLContext context = SSLContext.getInstance("TLS");
        context.init(null, null, null);
        internalSSLSocketFactory = context.getSocketFactory();
    }

    @Override
    public String[] getDefaultCipherSuites() {
        return internalSSLSocketFactory.getDefaultCipherSuites();
    }

    @Override
    public String[] getSupportedCipherSuites() {
        return internalSSLSocketFactory.getSupportedCipherSuites();
    }

    @Override
    public Socket createSocket() throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket());
    }

    @Override
    public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(s, host, port, autoClose));
    }

    @Override
    public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port));
    }

    @Override
    public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException, UnknownHostException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port, localHost, localPort));
    }

    @Override
    public Socket createSocket(InetAddress host, int port) throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port));
    }

    @Override
    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
        return enableTLSOnSocket(internalSSLSocketFactory.createSocket(address, port, localAddress, localPort));
    }

    private Socket enableTLSOnSocket(Socket socket) {
        if(socket != null && (socket instanceof SSLSocket)) {
            ((SSLSocket)socket).setEnabledProtocols(new String[] {"TLSv1.1", "TLSv1.2"});
        }
        return socket;
    }
}

And then use it in your connection

HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
TLSSocketFactory socketFactory = new TLSSocketFactory();
conn.setSSLSocketFactory(socketFactory);
conn.connect();