android Google Play Warning: SSL Error Handler Vulnerability

Atef Daoud picture Atef Daoud · Mar 1, 2016 · Viewed 17.7k times · Source

I use the gorbin/ASNE SDK in my app. I recently received an email from Google with the following subject : "Google Play Warning: SSL Error Handler Vulnerability". In this email, Google explains that my app has an ["unsafe implementation of the WebViewClient.onReceivedSslError handler"]

and they recommended me to ["To properly handle SSL certificate validation, change your code to invoke SslErrorHandler.proceed() whenever the certificate presented by the server meets your expectations, and invoke SslErrorHandler.cancel() otherwise"]

here's my implementation of the method :

   public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
                handler.proceed();
            }

any help please ?

Answer

Anant Shah picture Anant Shah · Jul 15, 2016

To properly handle SSL certificate validation, change your code to invoke SslErrorHandler.proceed() whenever the certificate presented by the server meets your expectations, and invoke SslErrorHandler.cancel() otherwise.

For example, I add an alert dialog to make user have confirmed and seems Google no longer shows warning.

    @Override
    public void onReceivedSslError(WebView view, final SslErrorHandler handler, SslError error) {
    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
    String message = "SSL Certificate error.";
        switch (error.getPrimaryError()) {
            case SslError.SSL_UNTRUSTED:
                message = "The certificate authority is not trusted.";
                break;
            case SslError.SSL_EXPIRED:
                message = "The certificate has expired.";
                break;
            case SslError.SSL_IDMISMATCH:
                message = "The certificate Hostname mismatch.";
                break;
            case SslError.SSL_NOTYETVALID:
                message = "The certificate is not yet valid.";
                break;
        }
        message += " Do you want to continue anyway?";

        builder.setTitle("SSL Certificate Error");
        builder.setMessage(message);
    builder.setPositiveButton("continue", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            handler.proceed();
        }
    });
    builder.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            handler.cancel();
        }
    });
    final AlertDialog dialog = builder.create();
    dialog.show();
}

After this changes it will not show warning. Reference