Get certificate and add it to a Java truststore, when only having https URL?

Question

I\'m trying to send push notifications to Android devices through the Google Cloud Message servers.

The URL we use to do that is:

https://android.goo         


        

Answer 1

I've been able to save the certificates through the following Java code:

public void testConnectionTo(String aURL) throws Exception {
        URL destinationURL = new URL(aURL);
        HttpsURLConnection conn = (HttpsURLConnection) destinationURL.openConnection();
        conn.connect();
        Certificate[] certs = conn.getServerCertificates();
        System.out.println("nb = " + certs.length);
        int i = 1;
        for (Certificate cert : certs) {
            System.out.println("");
            System.out.println("");
            System.out.println("");
            System.out.println("################################################################");
            System.out.println("");
            System.out.println("");
            System.out.println("");
            System.out.println("Certificate is: " + cert);
            if(cert instanceof X509Certificate) {
                try {
                    ( (X509Certificate) cert).checkValidity();
                    System.out.println("Certificate is active for current date");
                    FileOutputStream os = new FileOutputStream("/home/sebastien/Bureau/myCert"+i);
                    i++;
                    os.write(cert.getEncoded());
                } catch(CertificateExpiredException cee) {
                    System.out.println("Certificate is expired");
                }
            } else {
                System.err.println("Unknown certificate type: " + cert);
            }
        }
    }

And import them to the truststore:

keytool -import -alias GoogleInternetAuthority -file myCert1 -keystore truststore