Question

I’m having trouble with getting Android to connect to a simple OpenSSL server using the HttpsUrlConnection object (I’ve combed through StackOverflow and a bunch of online tutorials, and followed the examples pretty much line for line and I still can’t figure out why mine is broken when I use my local truststore).

I currently have an Android activity that attempts to connect to a simple OpenSSL server (I can connect to my server using a OpenSSL client), once the HttpsUrlConnection.connect() is called I receive a “javax.net.ssl.SSLException: Connection closed by peer" error during the SSL handshake. Perhaps I am setting up my sample server incorrectly?

Things to note:

• no client authorization at the moment
• am able to connect to https://www.google.com when loading default trust store
• am not able to connect to server on localhost with self-signed certificate
• do not want to trust all certificates
• do not want to use Apache HttpClient
• want to use local truststore only
• created local truststore with bouncy castle
• am able to correctly load truststore into
• behind a proxy firewall, proxy is set on my android virtual device
• AVD set to Android 4.1 API 16.

Things I have already tried:

• connecting to both 127.0.0.1 and 10.0.2.2
• using a new SecureRandom() with the SSLContext.init()
• creating the URL with 'URL u = new URL("https", "10.0.2.2", 443, "/");'
• using TrustManagerFactory.getDefaultAlgorithms() instead of the “X509”
  • gives "Unexpected response code error 503" instead of “Connection closed by peer”

Thank you in advance for taking the time to review my question!

Simple server started with command:

$ sudo openssl s_server -accept 443 -cert server-cert.pem -key server-key.pem -pass file:passphrase.txt -state -www -verify 0

Client connection tested with command:

$ openssl s_client -connect 127.0.0.1:443 

Android activity code (edited to remove complete running code for simplification – please let me know if more code is needed) – error output is below the code.

    try {
        TrustManagerFactory tmf;

        // local trust store
        tmf = TrustManagerFactory.getInstance("X509");
        tmf.init(loadLocalKeyStore(getApplicationContext()));

        // default trust store - works for https://www.google.com
        // tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        // tmf.init((KeyStore) null);

        SSLContext context = SSLContext.getInstance("TLS");
        context.init(null, tmf.getTrustManagers(), null);

        HostnameVerifier hostnameVerifier = org.apache.http.conn.ssl.SSLSocketFactory.STRICT_HOSTNAME_VERIFIER;
        URL u = new URL("https://10.0.2.2");

        HttpsURLConnection urlConnection = (HttpsURLConnection) u.openConnection();

        urlConnection.setSSLSocketFactory(context.getSocketFactory());
        urlConnection.setHostnameVerifier(hostnameVerifier);
        urlConnection.connect();

        System.out.println("Response Code: " + urlConnection.getResponseCode());
        System.out.println("Response Code: " + urlConnection.getCipherSuite());
    } 

    ...

    private KeyStore loadLocalKeyStore(Context context) {
        InputStream in = context.getResources().openRawResource(R.raw.newserverkeystore);
        KeyStore trusted = null;
        try {
           trusted = KeyStore.getInstance("BKS");
           trusted.load(in, "thisisasecret".toCharArray());
        } finally {
           in.close();
        }
       return trusted;
    }

Output when connecting correctly to https://www.google.com:

09-09 21:58:09.947: I/System.out(669): Response Code: 200
09-09 21:58:09.947: I/System.out(669): Response Code: TLS_ECDHE_RSA_WITH_RC4_128_SHA

Output when trying to connect to my server with self-signed certificate:

09-09 22:03:23.377: D/HttpsProxy(717): Https Request error
09-09 22:03:23.377: D/HttpsProxy(717): javax.net.ssl.SSLException: Connection closed by peer
09-09 22:03:23.377: D/HttpsProxy(717):  at org.apache.harmony.xnet.provider.jsse.NativeCrypto.SSL_do_handshake(Native Method)
09-09 22:03:23.377: D/HttpsProxy(717):  at org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:395)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpConnection.setupSecureSocket(HttpConnection.java:210)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:478)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:442)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:289)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:239)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:80)
09-09 22:03:23.377: D/HttpsProxy(717):  at libcore.net.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:165)
09-09 22:03:23.377: D/HttpsProxy(717):  at com.example.myfirstapp.HttpsUrlConnectionActivity$3.doInBackground(HttpsUrlConnectionActivity.java:257)
09-09 22:03:23.377: D/HttpsProxy(717):  at com.example.myfirstapp.HttpsUrlConnectionActivity$3.doInBackground(HttpsUrlConnectionActivity.java:1)
09-09 22:03:23.377: D/HttpsProxy(717):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
09-09 22:03:23.377: D/HttpsProxy(717):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
09-09 22:03:23.377: D/HttpsProxy(717):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
09-09 22:03:23.377: D/HttpsProxy(717):  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
09-09 22:03:23.377: D/HttpsProxy(717):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
09-09 22:03:23.377: D/HttpsProxy(717):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
09-09 22:03:23.377: D/HttpsProxy(717):  at java.lang.Thread.run(Thread.java:856)

Thanks again!!

Answer 1

I solved my problem – I needed to use a certificate with 10.0.2.2 as the common name (CN) so it matched Android localhost ip address of 10.0.2.2 instead of ‘localhost’ or ‘127.0.0.1’.

Edit: you could probably create a certificate with localhost as the CN and ‘127.0.0.1’ and ‘10.0.2.2’ as Subject Alternative Names (SAN).

Once I created 10.0.2.2 cert and private key pem files, I was able to hit my server running with the following command:

openssl s_server -accept 8888 -cert 10.0.2.2-cert.pem -key 10.0.2.2-key.pem  -state -www

If you want to force the client to provide a certificate (though it won’t be checked), add the flag -Verify 1 to the command above.

To test the server at the command line you can use the following (note openssl is able to connect via 127.0.0.1):

openssl s_client -connect 127.0.0.1:8888

And to add a client cert if the server requires it, add the flags -cert client-cert.pem -key client-key.pem

In my Android client I used the following code to connect (error checking removed):

// use local trust store (CA)
TrustManagerFactory tmf;
KeyStore trustedStore = null;
InputStream in = context.getResources().openRawResource(R.raw.mycatruststore); // BKS in res/raw
trustedStore = KeyStore.getInstance("BKS");
trustedStore.load(in, "insertBksPasswordHere".toCharArray());
tmf = TrustManagerFactory.getInstance("X509");
tmf.init(trustedStore);

// load client certificate
KeyStore clientKeyStore = loadClientKeyStore(getApplicationContext());
KeyManagerFactory kmf = KeyManagerFactory.getInstance("X509");
kmf.init(clientKeyStore, "insertPasswordHere".toCharArray());

SSLContext context = SSLContext.getInstance("TLS");

// provide client cert - if server requires client cert this will pass
context.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);
HostnameVerifier hostnameVerifier = org.apache.http.conn.ssl.SSLSocketFactory.STRICT_HOSTNAME_VERIFIER;

// connect to url
URL u = new URL("https://10.0.2.2:8888/");
HttpsURLConnection urlConnection = (HttpsURLConnection) u.openConnection();
urlConnection.setSSLSocketFactory(context.getSocketFactory());
urlConnection.setHostnameVerifier(hostnameVerifier);
urlConnection.connect();
System.out.println("Response Code: " + urlConnection.getResponseCode());

You should get a response code of 200, and can dissect the response from there.

Here’s the code to load the client credentials, which is identical to loading the server key store but with a different resource filename and password:

private KeyStore loadClientKeyStore(Context context) {
    InputStream in = context.getResources().openRawResource(R.yourKeyStoreFile);
    KeyStore trusted = null;
    trusted = KeyStore.getInstance("BKS");
    trusted.load(in, "yourClientPassword".toCharArray());
    in.close();
    return trusted;
}