accepting HTTPS connections with self-signed certificates

Morten picture Morten · Jan 6, 2010 · Viewed 301.6k times · Source

I'm trying to make HTTPS connections, using HttpClient lib, but the problem is that, since the certificate isn't signed by a recognized Certificate Authority (CA) like Verisign,GlobalSIgn, etc., listed on the set of Android Trusted Certificates, I keep getting javax.net.ssl.SSLException: Not trusted server certificate.

I've seen solutions where you simply accept all certificates, but what if I want to ask the user?

I want to get a dialog similar to that of the browser, letting the user decide to continue or not. Preferably I'd like to use the same certificatestore as the browser. Any ideas?

Answer

Nikolay Moskvin picture Nikolay Moskvin · Oct 11, 2010

The first thing you need to do is to set the level of verification. Such levels is not so much:

  • ALLOW_ALL_HOSTNAME_VERIFIER
  • BROWSER_COMPATIBLE_HOSTNAME_VERIFIER
  • STRICT_HOSTNAME_VERIFIER

Although the method setHostnameVerifier() is obsolete for new library apache, but for version in Android SDK is normal. And so we take ALLOW_ALL_HOSTNAME_VERIFIER and set it in the method factory SSLSocketFactory.setHostnameVerifier().

Next, You need set our factory for the protocol to https. To do this, simply call the SchemeRegistry.register() method.

Then you need to create a DefaultHttpClient with SingleClientConnManager. Also in the code below you can see that on default will also use our flag (ALLOW_ALL_HOSTNAME_VERIFIER) by the method HttpsURLConnection.setDefaultHostnameVerifier()

Below code works for me:

HostnameVerifier hostnameVerifier = org.apache.http.conn.ssl.SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER;

DefaultHttpClient client = new DefaultHttpClient();

SchemeRegistry registry = new SchemeRegistry();
SSLSocketFactory socketFactory = SSLSocketFactory.getSocketFactory();
socketFactory.setHostnameVerifier((X509HostnameVerifier) hostnameVerifier);
registry.register(new Scheme("https", socketFactory, 443));
SingleClientConnManager mgr = new SingleClientConnManager(client.getParams(), registry);
DefaultHttpClient httpClient = new DefaultHttpClient(mgr, client.getParams());

// Set verifier     
HttpsURLConnection.setDefaultHostnameVerifier(hostnameVerifier);

// Example send http request
final String url = "https://encrypted.google.com/";
HttpPost httpPost = new HttpPost(url);
HttpResponse response = httpClient.execute(httpPost);