Detect installed certificate in my android device

Question

I am installing a certificate in my application when application starts. I have gone through few of the links as below and successfully install the certificate.

• http://nelenkov.blogspot.in/2011/12/ics-trust-store-implementation.html

• http://pastebin.com/Bn6qSYHx

• How to programmatically install a CA Certificate (for EAP WiFi configuration) in Android?

• how to install CA certificate programmatically on Android without user interaction

I came to know we cannot install the certificate silently without user interaction.Currently I don't know how to stop prompt each time user open my app.

Whenever my application starts currently every time it ask user to install certificate. Is there some way I can detect whether a certificate(in this case my certificate) is already installed or not, programmatically.

Code snippet where I have installing certificate in my app

private void installCertificate()
    {
        try 
        {
            BufferedInputStream bis = new BufferedInputStream(getAssets().open(MY_CERT));
            byte[] keychain = new byte[bis.available()];
            bis.read(keychain);

            Intent installIntent = KeyChain.createInstallIntent();
            X509Certificate x509 = X509Certificate.getInstance(keychain);
            installIntent.putExtra(KeyChain.EXTRA_CERTIFICATE, x509.getEncoded());
            installIntent.putExtra(KeyChain.EXTRA_NAME, MY_CERT);
            startActivityForResult(installIntent, INSTALL_KEYCHAIN_CODE);
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        catch (CertificateException e) 
        {
            e.printStackTrace();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) 
    {
        if (requestCode == INSTALL_KEYCHAIN_CODE) 
        {
            switch (resultCode) 
            {  
                case Activity.RESULT_OK:
                    doTheTask();
                    break;
                case Activity.RESULT_CANCELED:
                    finish();
                    break;                  
                default:
                    super.onActivityResult(requestCode, resultCode, data);
            }
        }
    }

Also FYI, installCertificate() is called from onCreate().

Please help me out for the same. Any help will appreciated.

---

Query: When prompt comes for certificate name, entered text comes as selected and on orientation change cut/copy option comes. Any body knows how to stop text selection when prompt comes?!!!

Answer 1

I used the below piece of Java code to check whether or not my certificate is installed:

try
{
    KeyStore ks = KeyStore.getInstance("AndroidCAStore");
    if (ks != null) 
    {
        ks.load(null, null);
        Enumeration aliases = ks.aliases();
        while (aliases.hasMoreElements()) 
        {
            String alias = (String) aliases.nextElement();
            java.security.cert.X509Certificate cert = (java.security.cert.X509Certificate) ks.getCertificate(alias);

            if (cert.getIssuerDN().getName().contains("MyCert")) 
            {
                isCertExist = true;
                break;
            }
        }
    }
} catch (IOException e) {
    e.printStackTrace();
} catch (KeyStoreException e) {
    e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
    e.printStackTrace();
} catch (java.security.cert.CertificateException e) {
    e.printStackTrace();
}